Toyota Prius Hybrid: in the fight for efficiency and environmental friendliness. Avant-garde "Prius II" and inside looks unusual The main parts of the planetary mechanism

30.09.2019

1) Consumption in summer 19-19.5 km per 1 liter of fuel or 5-5.5 l / 100 km (with air conditioning), in winter 17-17.5 km per 1 liter of fuel or 5.5-6 l / 100 km (with oven and heating). It should not be anymore if the car is working. City-highway consumption does not make much difference, on the highway it is more if the speed is above 90 km / h, it increases by 1 liter / 100 km with an increase in speed for every 30 km / h.
2) Reliability. How many copies were broken in disputes about the reliability of hybrids and the Prius in particular, about its winter operation, as a result, there are more and more hybrids on the road, fewer and fewer pessimists. In the bottom line, we have: a simple hybrid installation (which requires replacing the antifreeze pump to cool the inverter after about 100-120 thousand kilometers and replacing antifreeze every 30 thousand kilometers), a planetary gearbox (the simplest, most unpretentious and reliable automatic transmission in Requires a fluid change every 50-70 thousand kilometers), the simplest suspension from a Corolla (MacPherson front, a beam at the back, there is nothing to break), an internal combustion engine from T. Corolla (very simple, but alas disposable).
3) Silence when driving at low speeds.
4) Start in any frost. VVB together with an inverter is the same as spinning it up and in what frost, they just do it and that's it.

1) The quality of interior materials and insulation. Badly. No velor, just a rag with plastic. Interior panel fastenings do not have vibration-damping elements, and the interior has sound-absorbing materials. Over time, it begins to creak, although the plastic is not hard, as in a domestic car, but nevertheless, it creaks anyway. You feel the whole budget of the car, but the Prius is what it is. In all subsequent models (30 and 40 bodies) it did not get better with this.
2) ICE from Corolla of the same model years (1nz). The internal combustion engine is the same, only "strangled" (less power, less emissions), the same aluminum cylinder block, with concomitant rapid wear of the piston group, a small amount of oil (if the engine does not eat it now, it will definitely start in the near future), blunt on the bottom, "bellowing" on the top, stable and efficient at medium speeds. You need to monitor it, change oils and filters regularly, it is advisable to decarbonize and use liquids to clean the injection system, then it does not threaten rapid wear, it takes a very long time.
3) Exterior for an amateur. But if you look closely, the 20 is very harmonious (roundness suits her), but absolutely not aggressive and not athletic (which embodies the 30).

Scheduled replacements (racks after 5 years of operation at home), oil every 5-6 thousand km, all filters as well.
At 90 thousand kilometers, I changed the front hub units (began to buzz), brake pads (there were still about 20% left on the native ones, the pads on the hybrid, if they are of high quality, they go up to 100 thousand km, since the hybrid slows down by recuperating electric energy, save on pads with their rare replacement does not make sense, only the original - then there will be no squeaks and frequent replacements).

By the way, explain to me how the ecological image of a defender of nature fits in with natural leather in interior trim ?! Or was it pleasant for cows to lie on the altar of hybridization of the planet Earth? To justify the Japanese, one can say that, most likely, the upholstery here is made of leatherette, and it is possible that not a single animal was harmed, as is sometimes written in the credits.

At least it's funny and interesting. While you understand this intricacies of buttons, you will master the basics of controlling hybrids. But such an architecture cannot be called comfortable, the feeling that the Japanese saved on interior equipment ...

Although it is not. Because those who choose the Prestige package for 1,374,000 rubles will not be deprived of the benefits of civilization. In winter, heated front seats will please. If it rains or it gets dark, the car will automatically turn on the windshield wipers and headlights. Cruise control maintains the set speed. But for another fashionable option you do not need to pay extra.

Chevrolet Corvette, BMW 5-series, Cadillac STS... But these prestigious cars are not the only ones that boast data projection on the windshield. There is this "trick" and the Toyota Prius. The car can tell you the way, instantaneous speed, fuel economy data.

And is the Prius convenient in terms of not high technology, but simply as a car? Let's put it this way: the car requires a short, but addictive. There are problems with visibility, the instruments are almost invisible, and the usual controls are not in place!

The gray-blue joystick is surprising at first, but you quickly get used to it. It is called the HSD selector and controls the transmission modes. True, to switch to parking mode, you need to press a separate key.

There are no special claims to landing behind the wheel. The seats are almost completely devoid of lateral support, but they are suitable for a quiet ride. When you're behind the wheel, two things are insanely annoying. The first is the disgusting sound of the seatbelt alarm. Here, smart cars understand that if you have a speed of 1.5 km / h, then you are parking the car, and the belt may interfere with you for now. Why is the Prius yelling so much with or without?! And the second wrong thing is a loud squeak while reversing. Is this made for underdeveloped drivers who have forgotten which way they are going?

A rearview camera with parking assistance is a sensible thing. True, it is not supplemented with parking sensors, but thanks to a clear picture and a large screen, it simplifies parking. So we got to the Toyota multimedia system. Oddly enough, it is quite common here, the same can be found on other models of the brand. The difference, perhaps, is only in the display of the hybrid drive. Around the monitor - as many as 14 keys. In my opinion, it's a clear overkill. As well as absolute unnecessary functions in the menu, such as the Calendar, for example.

Russified navigation system with a hard drive proved to be average. It works like a mediocre Range Rover system, for example, but not as well as a Nissan or BMW. The sound quality of the optional audio system with 8 speakers is not a revelation, it does not cause audiophilia. But it allows you to turn on a UBB flash drive or put a CD with your favorite tunes.

Management of almost all functions is displayed on the "beard" going from the dashboard down to the seats. The empty space under this console looks unusual. Under it are the keys for heating the front seats, and a power outlet. Designers have implemented the same idea of a “floating console” in the interiors of modern Volvos and in the related Toyota Auris. In front of the HSD lever we find a deep box covered with a lid. It is convenient to put a mobile phone in it. Just above the "emergency gang" button and the block of hybrid drive operating modes - climate control. You can choose different temperatures for the driver and passenger. But the most interesting thing is that, as in the Toyota Camry, you can adjust the “climate” from the steering wheel.

A rare case - the control of the air conditioning system is displayed on the steering wheel! By clicking here, you can change the temperature in the cabin, but this key controls the recirculation mode.

A very controversial decision seemed to finish the central armrest with dark leather. This "piece" stands out against the backdrop of a bright interior. Although, probably, for practicality it is even better - the dark gets dirty less. Another feature of the Prestige version is the Smart Entry smart car access system. It allows you to open the doors and trunk without getting the key. Convenient, although this feature could be offered at no additional cost.

Peering into the readings of digital instruments in a narrow loophole under the windshield is inconvenient. The energy distribution scheme does not carry any practical benefit, the speed is projected onto the windshield ... Only the circles that appear when you press the keys on the steering wheel are of interest. The feeling that the screen becomes three-dimensional!

Well, I have a feeling that the whole world is becoming, if not three-dimensional, then clearly somehow more modern. Driving a Prius, you want everyone to drive around silently, and the Moscow Ring Road would be covered with green grass with hares jumping on it. But as soon as you leave the Toyota showroom, you realize that no one needs all your concern for the environment in Russia so far. It’s a pity, because it’s already quite possible to drive hybrids!

Text: Dmitry Biryukov, Alexander Ignatiev
Photo: Sergey Usovik, AUTO RESULTS

For inner peace, the Prius gets 70 points. Unusual, modern, but problems with visibility need to be addressed!

PRIUS - leading the way!

11.08.2009

Hello, dear Priusovod! If you hold this book in your hands, then you can be called that with great confidence. This book will help you not only competently maintain and repair your car, but also understand the very principle of operation of the hybrid system and all the main components: high-voltage battery, inverter, motor generators, etc. Many Prius owners will find the book difficult, but let's not forget that some people not only drive Prius, but also want to know at least in general terms how this wonderful car works.

Let's start with why and why you bought this particular car. On the Internet, on forums dedicated to hybrid cars, a survey was repeatedly conducted on this topic. The main driving force that prompted owners to buy a Prius was (and this is not surprising) the desire to save on gasoline. In the context of the current crisis, this momentum becomes even more relevant. But something else surprised: the next argument for purchasing this car was not the desire to save on transport tax and insurance (although the savings, compared to a "simple" car, are really very significant), but "the desire to be at the forefront of technological progress and drive the car of the future"!

To understand this car of the future and fully feel the familiar Toyota slogan "drive the dream", this book will come in handy for you.

What types of hybrid engines exist

All types of hybrids can be divided into three groups:

1. Successive hybrids

2. Parallel hybrids

3. Series-parallel hybrids.

successive hybrids. Principle of operation: the wheels rotate from an electric motor, which is powered by a generator driven by an internal combustion engine. Those. Simplified: The internal combustion engine drives a generator that generates electricity for the traction motor. In this scheme, small volume and low power internal combustion engines and powerful generators are used. A clear drawback is that the batteries are charged and the car moves only when the internal combustion engine is constantly on.

The principle of a sequential hybrid cannot be applied to any mass-produced passenger car. It has more disadvantages than advantages.

parallel hybrids. Here the wheels can rotate both from the ICE drive and from the battery. But for this, the engine already needs a gearbox and the main disadvantage of this system: the engine cannot simultaneously turn the wheels and at the same time charge the battery. A good example of a parallel hybrid is the Honda Insight. It has an electric motor that can drive the car along with the internal combustion engine. This allows you to use a lower power internal combustion engine, because the electric motor will help out when more power is needed.

All these shortcomings are eliminated inseries-parallel hybrid. Depending on the driving conditions, it uses the traction of the electric motor separately, the traction of the gasoline engine with the possibility of simultaneous battery charging. In addition, a variant is possible when the joint effort of both a gasoline and an electric engine is used. Only in this way can the maximum efficiency of the power plant be achieved.

This series-parallel hybrid scheme is also used in your Toyota Prius. From the Latin "Prius" is translated as "advanced", or "going ahead".

I will say right away that today there are Toyota Prius in four bodies: 10, 11, 20 and 30. I will give their comparative data in the table "Comparative data of Prius cars of different years of manufacture."

When I talk about the Prius, I will have in mind the 20th body as the most common, and I will specifically specify all the differences from it in the 10th and 11th bodies.

In addition to the Prius, the hybrid system is used by Toyota on the following models: Alphard, Harrier, Highlander, Coaster, Crown, Camry and FCHV. At Lexus, Toyota's hybrid system is used in the RX400H (and its younger brother the RX450H), GS450H and LS600H.

In this work, many excerpts from the website of an American engineer, a specialist in the field of microprocessor technology, Graham Davis, were used.

The translation was carried out by Oleg Alfredovich Maleev (Burrdozel), a member of the AUTODATA forum, for which many thanks to him. I will try to explain to you the operation of all hybrid components with practical advice on the repair and maintenance of these components.

Hybrid Drive Components

Table. Comparative data of Prius cars of different years of production.

		Prius (NHW10)	Prius (NHW11)	Prius (NHW20)	Prius (ZVW30)
Start of sales		1997	2000	2003	2009
Drag coefficient		Cx = 0.26	Cx = 0.29	Cx = 0.26
Battery	Capacity, Ah	6,0	6,5	6,5	6,5
	Weight, kg	57	50	45	45
	Number of modules (number of segments per module)	40 (6)	38 (6)	28 (6)	28 (6)
	Total segments	240	228	168	168
	Voltage of one segment, V	1,2	1,2	1,2	1,2
	Total voltage, V	288,0	273,6	201,6	201,6
electric motor	power, kWt	30	33	50	60
Gas engine	Power, at rotational speed, kW / rpm	43/4000 (1NZ-FXE)	53/4500 (1NZ-FXE)	57/5000 (1NZ-FXE)	98/5200 (2ZR-FXE)
Engine volume, l		1.5 (1NZ-FXE)	1.5 (1NZ-FXE)	1.5 (1NZ-FXE)	1.8 (2ZR-FXE)
Synergic mode: power, kW (hp)		58 (78,86)	73 (99,25)	82 (111,52)	100 (136)
Acceleration from 0 to 100 km/h, s		13,5	11,8	10,9	9,9
Maximum speed (on the electric motor), km/h		160 (40)	170 (60)	180 (60)	-

Internal combustion engine

The Prius has an internal combustion engine (ICE), unusually small for a car weighing 1300 kg, with a volume of 1497 cm3. This is made possible by the presence of electric motors and batteries that help the internal combustion engine when more power is needed. In a conventional car, the engine is designed for high acceleration and steep climbing, so it almost always runs at low efficiency. On the 30th body, another engine is used, 2ZR-FXE, with a volume of 1.8 liters. Since the car cannot be connected to the city power supply network (which is planned by Japanese engineers in the near future), there is no other long-term source of energy and this engine must supply energy to charge the battery, as well as to move the car and power additional consumers such like air conditioner, electric heater, audio, etc.

The Toyota designation for the Prius engine is 1NZ-FXE.

The prototype of this engine is the 1NZ-FE engine, which was installed on Yaris, Bb, Fun Cargo, Platz cars. The design of many parts of the 1NZ-FE and 1NZ-FXE engines is the same. For example, the cylinder blocks of the Bb, Fun Cargo, Platz and Prius 11 are the same. However, the 1NZ-FXE engine uses a different mixture formation scheme, and therefore design differences are associated with this.

The 1NZ-FXE engine uses the Atkinson cycle, while the 1NZ-FE engine uses the conventional Otto cycle. In an Otto cycle engine, during the intake process, an air-fuel mixture enters the cylinder. However, the pressure in the intake manifold is lower than in the cylinder (because the flow is controlled by the throttle), and so the piston does the extra work of sucking in the air-fuel mixture, acting as a compressor. The intake valve closes near bottom dead center. The mixture in the cylinder is compressed and ignited at the moment the spark is applied. In contrast, the Atkinson cycle does not close the intake valve at bottom dead center, but leaves it open while the piston begins to rise. Part of the air-fuel mixture is forced into the intake manifold and used in another cylinder. Thus, pumping losses are reduced compared to the Otto cycle. Since the volume of the mixture that compresses and burns is reduced, the pressure during compression with this mixture formation scheme also decreases, which makes it possible to increase the compression ratio to 13, without the risk of detonation. Increasing the compression ratio increases the thermal efficiency. All these measures contribute to improving the fuel efficiency and environmental friendliness of the engine. The payoff is a reduction in engine power. So the 1NZ-FE engine has a power of 109 hp, and the 1NZ-FXE engine has 77 hp.

Motor/Generators

The Prius has two electric motors/generators. They are very similar in design, but differ in size. Both are three-phase permanent magnet synchronous motors. The name is more complex than the design itself. The rotor (the part that rotates) is a large, powerful magnet and does not have any electrical connections. The stator (the fixed part attached to the car body) contains three sets of windings. When current flows in a certain direction through one set of windings, the rotor (magnet) interacts with the magnetic field of the winding and is set in a certain position. By passing current in series through each set of windings, first in one direction and then in the other, the rotor can be moved from one position to the next, and so make it rotate.

Of course, this is a simplified explanation, but it shows the essence of this type of engine.

If an external force turns the rotor, the current flows through each set of windings in turn and can be used to charge a battery or power another motor. Thus, one device can be a motor or a generator depending on whether current is passed through the windings to attract the rotor magnets, or current is released when some external force turns the rotor. This is even more simplified, but will serve the depth of the explanation.

Motor/Generator 1 (MG1) is connected to the Power Distribution Device (PSD) sun gear. It is the smaller of the two and has a maximum output of around 18 kW. Usually, he starts the internal combustion engine and regulates the revolutions of the internal combustion engine by changing the amount of electricity produced. Motor/generator 2 (MG2) is connected to the ring gear of the planetary gear (power distribution device) and further through the gearbox to the wheels. Therefore, it directly drives the car. It is the larger of the two motor generators and has a maximum output of 33kW (50kW for the Prius NHW-20). The MG2 is sometimes referred to as a "traction motor" and its usual role is to propel the car as a motor or return braking energy as a generator. Both motors/generators are cooled with antifreeze.

inverter

In the same unit with the inverter, there is also a converter, which is designed to reverse convert AC voltage to DC - 13.8 volts.

To deviate a little from theory, a bit of practice: the inverter, like motor-generators, is cooled by an independent cooling system. This cooling system is powered by an electric pump.

If on body 10 this pump turns on when the temperature in the hybrid cooling circuit reaches about 48 ° C, then on bodies 11 and 20 a different algorithm for the operation of this pump is used: be “overboard” at least -40 degrees, the pump will still start its work already at turning on the ignition. Accordingly, the resource of these pumps is very, very limited. What happens when a pump jams or burns out: according to the laws of physics, under heating from MG (especially MG2), antifreeze rises up - into the inverter. And in the inverter, it must cool the power transistors, which heat up significantly under load. The result is their failure, i.e. the most common error on body 11: P3125 - inverter malfunction due to a burnt out pump. If in this case the power transistors withstand such a test, then the MG2 winding burns out. This is another common error on body 11: P3109. On the 20th body, Japanese engineers improved the pump: now the rotor (impeller) does not rotate in a horizontal plane, where the entire load goes to one support bearing, but in a vertical one, where the load is distributed evenly over 2 bearings. Unfortunately, this added little reliability. In April-May 2009 alone, 6 pumps on 20 bodies were replaced in our workshop. Practical advice for owners of 11 and 20 Prius: make it a rule at least once every 2-3 days to open the hood for 15-20 seconds with the ignition on or the car running. You will immediately see the movement of antifreeze in the expansion tank of the hybrid system. After that, you can drive safely. If there is no antifreeze movement there, you can’t drive a car!

high voltage battery

The Prius high-voltage battery (abbreviated as HVB) in the 10 body consists of 240 cells with a nominal voltage of 1.2 V, very similar to a D-size flashlight battery, combined in 6 pieces, into the so-called "bamboos" (there is a slight resemblance in appearance). "Bamboos" are installed in 20 pieces in 2 buildings. The total nominal voltage of the VVB is 288 V. The operating voltage fluctuates in idle mode from 320 to 340 V. When the voltage drops to 288 V in the VVB, starting the internal combustion engine becomes impossible. In this case, the battery symbol with the "288" icon inside will light up on the display screen. To start the internal combustion engine, the Japanese in the 10th body used a regular charger, which is accessed from the trunk. Frequently asked questions, how to use it? I answer: firstly, I repeat that it can only be used when the "288" icon is on the display. Otherwise, when you press the "START" button, you will simply hear a nasty squeak, and the red "error" light will light up. Secondly: you need to hook up a "donor" to the terminals of a small battery, i.e. either a charger or a well-charged powerful battery (but by no means a starting device!). After that, with the ignition OFF, press the "START" button for at least 3 seconds. When the green light turns on, the VVB will start charging. It will end automatically after 1-5 minutes. This charge is quite enough for 2-3 starts of the internal combustion engine, after which the VVB will be charged from the converter. If 2-3 starts did not lead to the start of the internal combustion engine (and at the same time "READY" ("Ready") on the display should not blink, but burn steadily), then it is necessary to stop useless starts and look for the cause of the malfunction. In the 11th body, the VVB consists of 228 elements of 1.2 V each, combined in 38 assemblies of 6 elements, with a total nominal voltage of 273.6 V.

The entire battery is installed behind the rear seat. At the same time, the elements are no longer orange "bamboos", but are flat modules in gray plastic cases. The maximum battery current is 80 A when discharging and 50 A when charging. The nominal capacity of the battery is 6.5 Ah, however, the car's electronics allow only 40% of this capacity to be used in order to prolong battery life. The state of charge can only change between 35% and 90% of the full rated charge. Multiplying the battery voltage and its capacity, we get the nominal energy reserve - 6.4 MJ (megajoules), and the usable reserve - 2.56 MJ. This energy is enough to accelerate the car, driver and passenger to 108 km / h (without the help of the internal combustion engine) four times. To produce this amount of energy, an internal combustion engine would require approximately 230 milliliters of gasoline. (These figures are only given to give you an idea of the amount of stored energy in the battery.) The vehicle cannot be driven without fuel, even when starting at 90% full rated charge on a long descent. Most of the time you have about 1 MJ of usable battery power. A lot of VVB gets into repair precisely after the owner runs out of gas (in this case, the "Check Engine" icon and a triangle with an exclamation mark will light up on the scoreboard), but the owner tries to "reach out" to refueling. After the voltage drops on the elements below 3 V, they "die". On the 20th body, Japanese engineers went the other way to increase power: they reduced the number of elements to 168, i.e. left 28 modules. But for use in an inverter, the battery voltage is increased to 500 V using a special device - a booster. An increase in the nominal voltage of MG2 in the NHW-20 body made it possible to increase its power to 50 kW without changing the dimensions.

VVB segments: NHW-10, 20, 11.

The Prius also has an auxiliary battery. This is a 12-volt, 28 amp-hour lead-acid battery, which is located in the left side of the trunk (in the 20 body - on the right). Its purpose is to energize the electronics and accessories when the hybrid system is off and the main high voltage battery relay is off. When the hybrid system is running, the 12-volt source is a DC/DC converter from the high-voltage system to 12-volt DC. It also recharges the auxiliary battery when needed.

The main control units communicate via the internal CAN bus. The remaining systems communicate over the Body Electronics Area Network.

The VVB also has its own control unit, which monitors the temperature of the elements, the voltage on them, the internal resistance, and also controls the fan built into the VVB. On the 10th body there are 8 temperature sensors, which are thermistors, on the "bamboos" themselves, and 1 is a common VVB air temperature control sensor. On the 11th body - 4 +1, and on the 20th - 3 + 1.

Power distribution device

The torque and energy of the internal combustion engine and motors/generators are combined and distributed by a planetary set of gears, called by Toyota "power split device" (PSD, Power Split Device). And although it is not difficult to manufacture, this device is quite difficult to understand and even more tricky to consider in full context all modes of operation of the drive. Therefore, we will devote several other topics to the discussion of the power distribution device. In short, this allows the Prius to operate in both series- and parallel-hybrid modes at the same time and get some of the benefits of each mode. The ICE can turn the wheels directly (mechanically) through the PSD. At the same time, a variable amount of energy can be taken from the internal combustion engine and converted into electricity. It can charge a battery or be passed on to one of the motors/generators to help turn the wheels. The flexibility of this mechanical/electrical power distribution allows the Prius to improve fuel efficiency and manage emissions while driving, which is not possible with a rigid mechanical connection between the combustion engine and the wheels, as in a parallel hybrid, but without the loss of electrical energy, as in a series hybrid.

The Prius is often said to have a CVT (Continue Variable Transmission) - continuously variable or "constantly variable" transmission, this is the PSD power distribution unit. However, a conventional continuously variable transmission operates exactly like a normal transmission, except that the gear ratio can change continuously (smoothly) rather than in a small range of steps (first gear, second gear, etc.). A little later, we will look at how the PSD differs from a conventional continuously variable transmission, i.e. variator.

Usually the most asked question about the "box" of a Prius car: what kind of oil is poured there, how much in volume and how often to change it. Very often, there is such a misconception among car service workers: since there is no dipstick in the box, it means that there is no need to change the oil there at all. This misconception has led to the death of more than one box.

10 body: working fluid T-4 - 3.8 liters. 11 body: working fluid T-4 - 4.6 liters.

20 body: ATF WS working fluid - 3.8 liters.

Replacement period: after 40 thousand km. According to Japanese terms, the oil is changed every 80 thousand km, but for especially difficult operating conditions (and the Japanese attribute the operation of cars in Russia to these especially difficult conditions - and we are in solidarity with them), the oil is supposed to be changed 2 times more often.

What else is interesting used in the transmission:

The use of a chain drive is rather uncommon, but all conventional cars have gear reduction gears between the engine and the axles. Their purpose is to allow the engine to spin faster than the wheels and also increase the engine generated torque to more torque at the wheels. The ratios with which rotational speed is reduced and torque increased are necessarily the same (neglect friction) due to the law of conservation of energy. The ratio is called the "total gear ratio". The total gear ratio of the Prius in the 11th body is 3.905. It turns out like this:

The 39-tooth sprocket on the PSD output shaft drives the 36-tooth sprocket on the first intermediate shaft through a silent chain (so-called Morse chain).

The 30-tooth gear on the first countershaft is connected to and drives the 44-tooth gear on the second countershaft.

The 26-tooth gear on the second countershaft is connected to and drives the 75-tooth gear at the differential input.

The value of the output of the differential to the two wheels is the same as the input of the differential (they are, in fact, identical, except when cornering occurs).

If we perform a simple arithmetic operation: (36/39) * (44/30) * (75/26), we get (to four significant digits) a total gear ratio of 3.905.

There is nothing very unusual about a Prius differential, axles and wheels. As in a conventional car, the differential allows the inner and outer wheels to spin at different speeds when the car turns. The axles transmit torque from the differential to the wheel hub and include an articulation to allow the wheels to move up and down following the suspension. The wheels are lightweight aluminum alloy and fitted with high pressure tires with low rolling resistance. The tires have a rolling radius of approximately 11.1 inches, which means the car moves 1.77 meters for each revolution of the wheel. Only the size of stock tires on 10 and 11 bodies is unusual: 165/65-15. This is a rather rare tire size in Russia. Many sellers, even in specialized stores, quite seriously convince that such rubber does not exist in nature. My recommendations: for Russian conditions, the most suitable size is 185/60-15. In the 20 Prius, the size of the rubber has been increased, which has a beneficial effect on its durability.

Now more interesting: what is missing in the Prius, what is in any other car?

This:

There is no stepped transmission, either manual or automatic - the Prius does not use stepped transmissions;

There is no clutch or transformer - the wheels are always hardwired to the ICE and motors/generators;

There is no starter - starting the internal combustion engine is done by MG1 through gears in the power distribution device;

There is no alternator - electricity is generated by motors/generators as needed.

Therefore, the design complexity of the Prius hybrid drive is actually not much greater than that of a conventional car. In addition, new and unfamiliar parts such as motors/generators and PSDs have higher reliability and longer life than some of the parts that have been removed from the design.

Vehicle operation in various driving conditions

Engine starting

To start the motor, MG1 (connected to the sun gear) rotates forward using the power from the high voltage battery. If the vehicle is stationary, the planetary ring gear will also remain stationary. The rotation of the sun gear therefore forces the planet carrier to rotate. It is connected to the internal combustion engine (ICE) and cranks it at 1/3.6 of the rotational speed of MG1. Unlike a conventional car, which supplies fuel and ignition to the internal combustion engine as soon as the starter begins to turn it, the Prius waits until MG1 has accelerated the internal combustion engine to approximately 1000 rpm. This happens in less than a second. The MG1 is significantly more powerful than a conventional starter motor. To rotate the internal combustion engine at this speed, it must itself rotate at a speed of 3600 rpm. Starting an ICE at 1000 rpm creates almost no stress on it because that is the speed at which an ICE would be happy to run on its own power. Also, the Prius starts by firing only a couple of cylinders. The result is a very smooth start, free of noise and twitch, which eliminates the wear and tear associated with conventional car engine starts. At the same time, I will immediately draw attention to a common mistake of repairmen and owners: they often call me and ask what prevents the internal combustion engine from continuing to work, why it starts for 40 seconds and stalls. In fact, while the READY frame is blinking, the ICE DOES NOT WORK! It turns him MG1! Although visually - a complete feeling of starting the internal combustion engine, i.e. The engine makes noise, smoke comes out of the exhaust pipe ...

Once the ICE has started to run on its own power, the computer controls the throttle opening to get the right idle speed during warm up. Electricity no longer powers MG1 and, in fact, if the battery is low, MG1 can generate electricity and charge the battery. The computer simply sets up MG1 as a generator instead of a motor, opens the engine throttle a little more (up to about 1200 rpm) and gets electricity.

Cold start

When you start a Prius with a cold engine, its top priority is to warm up the engine and catalytic converter so that the emission control system can work. The engine will run for several minutes until this happens (how long depends on the actual temperature of the engine and catalytic converter). At this time, special measures are taken to control the exhaust during warm-up, including keeping the exhaust hydrocarbons in the absorber to be cleaned later and running the engine in a special mode.

Warm start

When you start a Prius with a warm engine, it will run for a short time and then stop. Idling will be within 1000 rpm.

Unfortunately, it is not possible to prevent the internal combustion engine from starting when you turn on the car, even if all you want to do is move to a nearby lift. This only applies to 10 and 11 bodies. On the 20th body, a different start algorithm is applied: press the brake and the "START" button. If there is enough energy in the VVB, and you do not turn on the heater to heat the interior or glass, the internal combustion engine will not start. The inscription "READY" ("Ready") will simply light up, i.e. the car is COMPLETELY ready to move. It is enough to switch the joystick (and the choice of modes on the 20th body is done with the joystick) to position D or R and release the brake, you will go!

Starting off

The Prius is always in direct gear. This means that the engine alone cannot provide all the torque to drive the car vigorously. The torque for the initial acceleration is added by the MG2 motor driving directly the planetary ring gear connected to the gearbox input, the output of which is connected to the wheels. Electric motors develop the best torque at low rpm, so they are ideal for starting a car.

Let's imagine that the ICE is running and the car is stationary, which means that the motor MG1 rotates forward. The control electronics starts to take energy from the generator MG1 and transfers it to the motor MG2. Now, when you take energy from a generator, that energy has to come from somewhere. There is some force that slows down the rotation of the shaft and something that rotates the shaft must resist this force in order to maintain speed. Resisting this "generator load", the computer speeds up the internal combustion engine to add more power. So, the ICE is turning the planet carrier more hard, and MG1 is trying to slow down the rotation of the sun gear. The result is a force on the ring gear that causes it to rotate and start moving the car.

Recall that in a planetary gear, the torque of the internal combustion engine is divided 72% to 28% between the crown and the sun. Until we pressed the accelerator pedal, the ICE was just idling and producing no output torque. Now, however, the revs have been added and 28% of the torque is turning MG1 like a generator. The other 72% of the torque is transferred mechanically to the ring gear and therefore to the wheels. While most of the torque comes from the MG2 motor, the ICE does transfer torque to the wheels in this way.

Now we have to figure out how the 28% of the ICE torque that goes to MG1 can possibly boost the car's start with MG2. To do this, we must clearly distinguish between torque and energy. Torque is a rotating force, and just like a straight line force, no energy is required to maintain the force. Suppose you are pulling a bucket of water with a winch. She takes energy. If the winch is driven by an electric motor, you would have to supply it with electricity. But, when you have raised the bucket to the top, you can hook it with some kind of hook or rod or something else to keep it on top. The force (weight of the bucket) that is applied to the rope and the torque transmitted by the rope to the winch drum has not disappeared. But because the force does not move, there is no transfer of energy, and the situation is stable without energy. Likewise, when the vehicle is stationary, even though 72% of the ICE's torque is being sent to the wheels, there is no energy flow in that direction since the ring gear is not rotating. The sun gear, however, rotates quickly, and although it receives only 28% of the torque, this allows a lot of electricity to be generated. This line of reasoning shows that MG2's task is to apply torque to the input of a mechanical gearbox that does not require much power. A lot of current must pass through the motor windings, overcoming electrical resistance, and this energy is wasted as heat. But when the car is moving slowly, this energy comes from MG1.

As the vehicle starts to move and picks up speed, MG1 rotates more slowly and produces less power. However, the computer may increase the speed of the internal combustion engine a little. Now more torque is coming from the ICE and since more torque must also go through the sun gear, MG1 can keep the power generation high. The reduced rotational speed is compensated by an increase in torque.

We've avoided mentioning the battery up to this point to make it clear how it's not necessary to get the car going. However, most starting is the result of the computer transferring power from the battery directly to the MG2 motor.

There are ICE speed limits when the car is moving slowly. They are due to the need to prevent damage to MG1, which will have to rotate very quickly. This limits the amount of power produced by the internal combustion engine. In addition, it would be unpleasant for the driver to hear that the ICE is revving up too much for a smooth start. The harder you press the accelerator, the more the ICE will rev up, but also the more power will come from the battery. If you put the pedal to the floor, approximately 40% of the energy comes from the battery and 60% from the internal combustion engine at a speed of about 40 km / h. As the car accelerates and the ICE revs up at the same time, it delivers most of the power, reaching about 75% at 96 km/h if you're still pushing the pedal to the floor. As we remember, the energy of the internal combustion engine includes what is taken by the generator MG1 and transferred in the form of electricity to the motor MG2. At 96 km/h, the MG2 actually delivers more torque, and therefore more power to the wheels, than is supplied through the planetary gear from the internal combustion engine. But most of the electricity it uses comes from MG1 and therefore indirectly from the ICE and not from the battery.

Accelerating and driving uphill

When more power is needed, the ICE and MG2 work together to generate torque to drive the car in much the same way as described above for starting off. As the vehicle speed increases, the amount of torque the MG2 is able to deliver decreases as it starts to operate at its 33kW power limit. The faster it spins, the less torque it can put out at that power. Fortunately, this is consistent with the driver's expectations. When a conventional car accelerates, the gear box shifts up and torque on the axle is reduced so that the engine can reduce its speed to a safe value. Although it is done using completely different mechanisms, the Prius gives the same overall feel as accelerating in a conventional car. The main difference is the complete absence of "jerking" when shifting gears, because there is simply no gearbox.

So, the internal combustion engine rotates the carrier of the satellites of the planetary mechanism.

72% of its torque is sent mechanically through the ring gear to the wheels.

28% of its torque is sent to the MG1 generator via the sun gear, where it is converted into electricity. This electrical energy feeds the MG2 motor, which adds some extra torque to the ring gear. The more you press the accelerator, the more torque the internal combustion engine produces. It increases both the mechanical torque through the crown and the amount of electricity produced by the MG1 generator for the MG2 motor used to add even more torque. Depending on various factors such as the state of charge of the battery, the grade of the road, and especially how hard you pedal, the computer may direct additional battery power to MG2 to increase its contribution. This is how acceleration is achieved, sufficient to drive such a large car with an internal combustion engine with a power of only 78 hp on the highway. With.

On the other hand, if the required power is not so high, then some of the electricity produced by MG1 can be used to charge the battery even when accelerating! It is important to remember that the ICE both turns the wheels mechanically and turns the MG1 generator, causing it to produce electricity. What happens to this electricity and whether more battery electricity is added depends on a complex of reasons that we cannot all account for. This is handled by the vehicle's hybrid system controller.

Driving at moderate speed

Once you have reached a steady speed on a flat road, the power that should be supplied by the engine is used to overcome aerodynamic drag and rolling friction. This is much less than the power needed to drive uphill or accelerate a car. In order to operate efficiently at low power (and also not create a lot of noise), the internal combustion engine runs at low speeds.

The following table shows how much power is needed to move the car at different speeds on a level road and the approximate rpm.

Vehicle speed, km/h	Power required for movement, kW	Engine speed, rpm	Turns of generator MG1, rpm
64	3,6	1300	-1470
80	5,9	1500	-2300
96	9,2	2250	-3600

We know from the section on power distribution devices that MG1 must reverse torque on the sun gear. This is, as it were, the fulcrum of the lever, with the help of which the internal combustion engine rotates the ring gear (and hence the wheels). Without MG1 drag, the ICE would simply spin MG1 instead of propelling the car. When MG1 rotated forward, it was easy to see that this reverse torque could be generated by the generator load. Therefore, the inverter electronics had to take power from MG1, and then reverse torque appeared. But now MG1 is spinning backwards, so how do we get it to generate this reverse torque? Ok, how would we make MG1 spin forward and produce straight torque? If only it worked like a motor! The opposite is true: if MG1 is rotating backwards and we want to get torque in the same direction, MG1 must be the motor and rotate using the electricity supplied by the inverter.

It's starting to look exotic. ICE pushes, MG1 pushes, MG2, what, pushes too? There is no mechanical reason why this cannot happen. It may look attractive at first sight. The two engines and the internal combustion engine all contribute to the creation of the movement at the same time. But, we must recall that we got into this situation by reducing the speed of the internal combustion engine for efficiency. It wouldn't be an efficient way to get more power to the wheels; to do this, we must increase the ICE RPM and return to the earlier situation where MG1 is spinning forward in generator mode. There is one more problem: we have to figure out where we are going to get energy to rotate MG1 in motor mode? From a battery? We can do this for a while, but soon we will be forced to leave this mode, left without battery power to accelerate or climb the mountain. No, we must receive this energy continuously, without allowing the battery to run low. Thus, we came to the conclusion that the energy should come from MG2, which should work as a generator.

Does generator MG2 produce power for motor MG1? Since both the ICE and MG1 contribute power that is combined by a planetary gear, the name "power combining mode" has been suggested. However, the idea of MG2 producing power for the MG1 motor was so at odds with people's ideas about how the system would work that a name was coined that has become generally accepted - "Heretical Mode".

Let's go over it again and change our point of view. The internal combustion engine rotates the planet carrier at low speed. MG1 rotates the sun gear backwards. This causes the planets to rotate forward and adds more rotation to the ring gear. The crown gear still only receives 72% of the ICE torque, but the speed at which the ring rotates is increased by moving the MG1 motor backwards. Rotating the crown faster allows the car to go faster at low engine speeds. MG2, unbelievably, resists the car's movement like a generator, and produces electricity that powers MG1's motor. The car is propelled forward by the remaining mechanical torque from the internal combustion engine.

You can determine that you are moving in this mode if you are good at determining the engine speed by ear. You are driving forward at a decent speed and you can barely hear the engine. It can be completely masked by road noise. The Energy Monitor display shows the ICE engine's power to the wheels and the motor/generator charging the battery. The picture can change - the processes of charging and discharging the battery to the motor alternate in order to turn the wheels. I interpret this alternation as adjusting the MG2 generator load to keep the driving energy constant.

Coasting

When you take your foot off the accelerator pedal, you can say that you are moving "coasting". The engine does not try to push the car forward. The car gradually slows down due to rolling friction and aerodynamic drag. In a conventional car, the engine is still connected to the wheels by the transmission. The engine cranks without fuel and therefore also slows down the vehicle. This is called "engine braking". While there is no reason for this to happen in the Prius, Toyota decided to give the car the same feel as a regular car by simulating engine braking. When you are coasting, the vehicle slows down faster than if only rolling and aerodynamic drag were acting on it. To generate this additional retarding force, MG2 turns on as a generator and charges the battery. Its generator load simulates engine braking.

Because the engine is not needed to drive the car, it can stop. The pinion carrier is stopped and the ring gear is still rotating. MG2, remember, is connected directly to the ring gear. The satellites rotate forward and MG1 rotates backward. Energy is not produced or consumed by MG1; it just spins freely.

However, we know that MG1 rotates backward 2.6 times faster than the ring gear and MG2 rotates forward. This situation is not safe when the car is driving at high speed. At speeds of 67 km/h or more, if the planet carrier is left stationary, the MG1 will rotate backward at over 6500 rpm. Therefore, to prevent this from happening, the computer turns on MG1 as a generator and starts to remove energy. The generator load prevents MG1 from over-revving, and instead the planetary carrier begins to rotate forward. With the planet carrier and ICE rotating at 1000 rpm, the MG1 is protected at speeds up to 104 km/h. At higher speeds, the planet carrier and ICE should spin faster. The electricity generated by MG1 in this mode can be used to charge the battery.

Braking

When you want to slow the car more quickly than when coasting (coasting) - from rolling resistance, aerodynamic drag and engine braking, you press the brake pedal. In a conventional car, this pressure is transmitted by a hydraulic circuit to the friction brakes in the wheels. The brake pads are pressed against the metal discs or drums and the driving energy of the car is converted into heat and the car slows down. The Prius has exactly the same brakes, but it has something else - regenerative braking. Whereas during coasting, MG2 generates some gen load to simulate engine braking, when the brake pedal is depressed, MG2's power generation increases and the much larger gen load contributes to vehicle deceleration. Unlike friction brakes, which waste the car's kinetic energy to generate heat, the electricity generated by regenerative braking is stored in a battery and will be used later. The computer calculates how much deceleration will be produced by regenerative braking and reduces the hydraulic pressure transmitted to the friction brakes by the appropriate amount.

In a normal car, on a steep downhill, you might decide to downshift to increase the amount of engine braking. The engine spins more quickly and holds the car back more, helping the brakes slow it down. The same choice is available in the Prius if you choose to use it. If you move the mode select lever to position "B", the engine will be used for braking. Whereas the engine is normally stopped in braking mode, in "B" mode the computer and motors/generators are arranged to spin the ICE without fuel and with the throttle nearly closed. The resistance it creates slows the car down by reducing brake heat and allows you to ease your brake pressure.

How the Prius "creeps" and starts on electricity

A conventional automatic transmission car will start moving if you take your foot off the brake pedal. This is a side effect of the torque converter, but it beneficially prevents the car from rolling backwards on a hill while you put your foot on the accelerator pedal. They say that the car "creeps". As with engine braking, there's no reason why the Prius should behave this way, except that Toyota wants drivers to feel familiar. Therefore "crawling" is also simulated. A small amount of battery power is transferred to the MG2 motor when you release the brake. She gently pushes the car forward.

If you press the accelerator a little, the energy supplied to the MG2 motor will be increased and the car will move more quickly. Since the MG2 is quite powerful and has high torque, you can start on electric only up to a decent speed, as long as the traffic allows you to gently accelerate. The more you press down on the accelerator, the sooner the ICE will fire up and start assisting you with its torque and the electricity generated by MG1.

If you press the pedal to the floor, the ICE will start immediately, although you will leave the line before it helps acceleration and contributes a lot of energy. But, for most starts inside the city, you will drive away from the line in near silence, using only the battery-powered MG2 motor. The ICE remains off and MG1 spins freely backwards.

Slow driving and "electric vehicle mode" ("EV mode")

Above, I described how the car will run using only electricity and the MG2 motor if you do not press the accelerator pedal hard. If you reach the desired speed before the engine starts, you can continue driving using only electric power. This is called "EV mode" because the car is powered in exactly the same way as a real EV. The ring gear rotates as MG2 powers the vehicle, the planetary carrier and ICE stop, the sun gear and MG1 rotate freely backwards.

Even if the ICE starts up during acceleration, when you have reached speed and reduced pedal pressure, the energy needed to keep going may drop to a level that the motor can easily provide.

MG2. The ICE will then turn off and you will be in EV mode. It's hard to predict when this will happen as it depends on various factors - how charged the battery is and other driving circumstances. However, after some time of driving in electric vehicle mode, the battery level will definitely decrease and the chances of the ICE to start to run at high speed and recharge the battery will increase.

The way the ICE starts in EV mode when it becomes necessary is similar to a warm start, but the crown and sun gear are not stationary. The sun gear rotates backwards and must first slow down. This may be enough to get the ICE up to its starting speed depending on the speed of the car, and the sun may have to change direction and start spinning forward. To slow down the sun gear, MG1 first works in generator mode and energy is removed. However, as the speed of MG1 drops close to zero, it must be turned on as a forward rotation motor and energized so as to quickly change the direction of rotation, pass the zero point and begin to rotate forward. As a result, as in the case of starting the engine in a stationary car, the carrier of the satellites, and with it the internal combustion engine, rotate forward. The forward rotating ring gear of the planetary gear in the vehicle powered by MG2 helps to accelerate the ICE to starting speed at the lower speed of MG1. However, the start of the internal combustion engine creates resistance to the free rotation of the ring gear. So that this jerk is not felt by the driver and passengers, not to mention the coffee in the cup holder, an additional impulse of energy is applied to MG2 to obtain the extra torque needed to start the internal combustion engine.

In the 20th body (on Japanese and European versions), the "EV" button is included as standard; push button forcing the "electric car" function. On American modifications, this button can be installed additionally.

Slow down and downhill

When you gently decelerate or go downhill, the energy needed to move decreases because inertia or gravity helps you move forward. Therefore, you slightly reduce the pressure on the accelerator pedal. If you slow down a little or go down a small hill quickly, the engine power and rpm will decrease somewhat, but this is difficult to notice. For more deceleration or steeper descents, depending on speed, the ICE may stop producing power altogether if MG2 can supply what is needed.

I have already described how, when moving slowly, the MG2 motor can supply all the necessary energy with the ICE stopped. Accelerating and moving horizontally at a constant speed, electric vehicle mode is hardly possible at speeds above 64 km/h, because the power requirement needed to overcome aerodynamic drag is enough to make the internal combustion engine turn on. EV mode at higher speeds can occur, however, under certain conditions and is very likely to occur when decelerating or going downhill quickly. To operate in EV mode at 67 km/h and above, the vehicle must protect the MG1 from very high RPMs in the same way as when coasting. The only difference is that the ring gear is not driven by vehicle movement, but by the MG2 motor. Alternator MG1 is still producing power to resist over-rotation, so the ICE ends up cranking. Fuel and ignition are not supplied. Of course, by doing this, MG1 removes energy that would otherwise accelerate the car. Some of the losses go to spinning the ICE, but some of it shows up as power generated by MG1. It simply returns to the high voltage source to partially replenish the energy consumed by MG2.

Reverse

The Prius does not have any reverse gears that would allow the car to be driven in reverse by the ICE. Therefore, it can only move backwards with the help of the MG2 electric motor.

DVS cannot help directly. In most cases, the vehicle will stop the ICE when you move the mode selector to the "R" position. Since MG2 rotates the gearbox input backwards, the planetary ring gear will also rotate backwards. The internal combustion engine is motionless, which means that the carrier of the satellites is also motionless. This simply means that MG1 will rotate forward. It rotates freely without consuming or producing energy. It's similar to EV mode, but in reverse. The computer will not allow you to drive in reverse at such a speed that the MG1 spins too fast.

If the ICE continues to run when the mode selector lever is in the R position, for example if the battery charge is low, then MG2 still simply drives the car in reverse as before. The only difference is that the planetary carrier rotates forward, the sun gear and MG1 rotate more rapidly forward, and the computer must limit the vehicle's rear speed to a lower value to protect MG1 from too much rotation. Power can be taken from the MG1 generator to power MG2 and charge the battery.

The Dangers of Hybrid Repair

With all new technologies come dangers, real and imagined. Will using your cell phone for hours on end eventually fry your brain? Will a radial keratotomy improve your vision or ruin it? It can be surprising how new technologies become familiar and taken for granted. We forget even the most real danger. We are calmly rushing with one and a half tons of steel, glass and rubber along the highway at a speed of 90 km / h, a few meters from similar objects traveling at the same speed in the opposite direction, constantly having ten or more liters of flammable liquid in a thin steel tank under the bottom car. But when someone put a powerful electrical system in a car, we suddenly get nervous. In this section, I would like to talk about the dangers of maintaining and repairing a Prius.

High voltage

A home electric heater runs on 220 volts and draws up to 30 amps. The Prius high voltage system operates at approximately 273 volts - slightly more than a heater. Currents can exceed 30 A, but in the event of an electric shock, the current passing through your body, which causes electrical injury, matters. Any electrical system that can produce an amp or more is just as dangerous as any other. The degree of damage that occurs from a 273 V electric shock depends on the electrical resistance of the body and the current path through the body. It happens that a person experiences a shock of 220 volts from one hand to the other, right across the heart, with little more than temporary discomfort. If you are not stupid, you can operate the heater and repair it without worrying about electric shocks. In the same way, and for the same reason, you can repair and service the Prius.

There is only one difference. It's been a long time since I've heard of household appliances crashing into each other in your living room. But you hear about car accidents all the time. Suppose someone broke into your home and attacked your heater with a sledgehammer. You come home and see dangling wires. Do you touch them? No, of course not. This is what Toyota has in mind when it advises you not to touch wires hanging from your vehicle after an accident. In the Prius, the high voltage wires are surrounded by a metal shield to prevent them from breaking. They are colored orange. I would say that the danger of electric shock is zero.

Spilling battery electrolyte

Cars have batteries. Batteries contain acid. Acid is dangerous. A car with powerful batteries must contain a lot of acid and be very dangerous, right?

The electrolyte in Prius NiMH batteries is potassium hydroxide. It's not an acid, it's an alkali, the complete opposite. Of course, concentrated lye can be just as caustic and dangerous as acid, which is why the documentation contains spill warnings. This should not be scary, since the location of the battery in the car protects it well, and each battery cell contains a very small amount of electrolyte. By far the biggest secondary risk in a crash, in my opinion, is gasoline, just like any normal car.

Driving in stealth mode

Its meaning is that you can move silently. This term is unfortunate because it is obviously not always a good idea.

Also, people talk about "stealth mode". In the 20th body, the "stealth" mode can be turned on forcibly with the "EV" button.

You can also influence the car with the way you drive, but you should probably master this "advanced Prius capability" first. In fact, the Prius philosophy of "just drive the dream" allows you to leave problem solving up to the car. Those of us who are looking for extreme economy and a more complete understanding of how a car works are the ones who talk the most about "stealth mode" or "EV" (electric vehicle) mode.

Auxiliary battery discharge

The first precaution in handling the Prius is to prevent the auxiliary battery from draining. Unlike in a conventional car, where a 12V battery has to supply power to the starter, the Prius 12V battery does not have any large stored energy requirements and therefore has a small capacity of 28Ah. It can be discharged in a very short time by leaving the interior lights on, doors ajar, or the interior fan running when the car is not running. It can also be discharged even if all lights and other consumers are turned off. The auxiliary battery current was measured and recorded.

I reproduce the data here: (for the 11th body)

Obviously, if you leave the car for a while, you must make sure that the headlight and parking light switch is turned OFF. Leaving the switch in the "on" position and letting the car turn off the headlights on its own would be fine for a week or two. 0.036 A will use up the 28 Ah capacity in the battery in 28 / 0.036 = 778 hours or 32 days. So, less than a month should be safe, but not longer.

If the Prius hasn't been driven for a month or more (eg, winterized in a garage) for a month or more (eg, waiting for parts), here are some methods to keep the auxiliary battery from draining:

Have someone turn the car on every few weeks and let him charge the auxiliary battery,

Disable auxiliary battery (You will lose radio settings and clock settings),

Connect charger to auxiliary battery.

If you don't take these steps, the worst thing that can happen is a dead battery. You can light up and start the Prius in the usual way from another car (although it is not recommended to start other cars from the Prius). There is no need to turn on the engine on another vehicle due to low energy consumption. You can also start from another battery. Lightweight auxiliary wires will work just as well as thick jumper cables. The only thing to be aware of is that every time a lead-acid battery is completely discharged, its life is shortened.

High voltage battery discharge

The second concern is the discharge of the high voltage battery. It won't happen as quickly as the 12-volt auxiliary battery drains, but when it does happen, something more serious can happen. If the charge level falls below the programmed level, the car will not start. On the 10th body of the VVB, you can recharge, as I said earlier, using a regular charger. On the 11th and 20th bodies, you will have to charge the VVB forcibly. This is quite laborious and requires a certain qualification in the performance of work. The high voltage battery is completely disconnected when the vehicle's ignition is turned off. No current leaks from the battery. Unfortunately, Nickel Metal Hydride (NiMH) batteries have a feature called "self-discharge" whereby they lose charge even when nothing is connected to the battery. 2% charge loss per day is often listed on NiMH batteries (used at home at room temperature), but this may not be true for Prius batteries.

Toyota's recommendation, which appeared on its Web site in the FAQ section, is to start the Prius engine every two months and let it run for 30 minutes. Of course, you will need to reconnect the auxiliary battery if you have previously disconnected it. You can be more relaxed, for example, in winter, as the self-discharge rate decreases at low temperatures. One must be more careful at high temperature when self-discharge increases.

You can find a description of the procedures for repairing, diagnosing and servicing a Toyota Prius in the book "Toyota Prius 2003-2009" at:

You can find individual articles on many elements of a hybrid installation on the Legion-Avtodata website -

Toyota Prius it is a full hybrid vehicle with proprietary Hybrid Synergy Drive technology. Among the main features of the car are high environmental friendliness (with a margin it covers the requirements of Euro-5) and efficiency (combined consumption is less than 5 liters / 100 km). This is the third generation of the model, significantly redesigned and improved. In addition, 2010 models use LED dipped beam.

Let's try to understand the features of the hybrid drive and check the car in the city and on the highway.

2. In fact, there are two big players in the hybrid car market: Toyota Prius and Honda Insight. Of course, there are other models of hybrids, but I will not list them, because they are much less popular and well-known. Both models have been produced since the late 90s, mainly for the US and European markets. The difference between them lies in the types of hybrid installation - the Prius, as I mentioned above, is a full-fledged hybrid (details below), while the Honda Insight hybrid installation works in parallel (the electric motor helps the gasoline engine, but the car cannot move only on electric traction). In Russia, they began to officially sell only the last, third generation Prius.

3. Let's start with a hybrid power plant. Under the hood is a 1.8-liter gasoline engine (in the previous generation, a 1.5-liter engine was used), two motor generators, a planetary gear and an inverter. The battery is located behind the backs of the rear seats, under the floor of the luggage compartment.

4. The gasoline engine runs on the Atkinson cycle, although this is not a completely true statement. In reality, a simplified analogue is used, working according to the Miller cycle, due to the fact that the creation of an engine according to the Atkinson cycle requires a very complex crank mechanism. In a nutshell, the Atkinson cycle is characterized by an increased time phase of the working stroke. In practice, this gives higher rates of efficiency and environmental friendliness, but traction is lost at low speeds. In a hybrid car, this is compensated by an electric motor that delivers maximum torque over a wide rev range. To increase efficiency, all attachments were removed from the engine: a water pump and an electric air conditioner compressor. In addition, there is no starter, its role is played by one of the electric motors.

For clarity, I made a diagram that will allow you to understand the principle of operation of a hybrid drive. In fact, the design is very simple. On the left we have a gasoline engine, which is connected to the first motor-generator. On the right we have the second, traction motor-generator. It is connected to the inverter, which in turn is connected to the battery and the first motor-generator. In the center is a planetary gear, which sums up the power flows on the left and right and transmits the torque to the gearbox and final drive to the wheels. The planetary gear completely replaces the gearbox and works on the principle of a continuously variable variator.

5. How does it work? At the start, only the traction motor works, if necessary, a gasoline engine is automatically connected to it. It is launched by the first motor-generator, which does it very smoothly and imperceptibly by adjusting the speed of revolutions. The moment from the gasoline engine is transmitted to the planetary gear, as well as (!) To the first motor-generator, which operates in generator mode and outputs energy to the inverter, which in turn redirects the received energy either to the battery for recharging, or to the traction electric motor, the moment from which through the planetary gear is transmitted to the wheels. The result is a closed cycle, where the main role is played by the traction electric motor, and the gasoline engine works on the pickup. When braking, the traction motor operates in generator mode and all the energy received is stored in the battery.

The power of the gasoline engine is 98 hp, and the traction electric motor is 79 hp. At the same time, the total power of the hybrid drive is 136 hp. The loss of horsepower is due to the fact that the current given off by the battery is electronically limited, and the electric motor is actually running at half its capacity. But, as the experiment showed, the degree of battery charge has absolutely no effect on the dynamic characteristics and acceleration time to 100 km / h.

6. Prius noticeably stands out in the city stream with its streamlined shape. Past generations of Prius looked really ridiculous, but the latest model is quite cute. The drag coefficient Cx is 0.26. This is one of the best indicators for production cars.

7. LED optics (details below). The rims are fitted with aerodynamic caps. They look the same, to be honest. In practice, their presence reduces fuel consumption by only 1-2 percent. It is more correct to make them completely closed, but then there will be a problem of cooling the brake mechanisms.

8. The main innovation on the 2010 model is the LED low beam. The block headlight consists of several modules. At the top is a parking light (surprisingly with a halogen lamp), on the right is a classic high beam module with a reflector and a halogen lamp. The dipped beam is divided into three modules. Two lensed modules that give a clear and focused light beam into the distance. Above them is a diffused light module to illuminate the area near the car. The front turn signals are placed on the bumper, next to the fog lights. The total power consumption of the low beam section is 33 watts, which is comparable to conventional xenon. But between them there is a colossal difference in the power of light. Light head and shoulders above any, the best xenon.

9. Compared to the previous generation, the rear of the Prius remained virtually unchanged. Similar taillights and a two-piece bevelled glass tailgate with spoiler. The visual absence of the exhaust pipe hints at the car's loyal attitude towards the environment.

10. The most popular Prius received in the US, and this is their main market (without forgetting that at home, in Japan, they are also very popular). There are many owners clubs out there who are trying to squeeze the lowest fuel consumption out of the Prius. Often meaningless, from the point of view of practical application, an occupation attracts a very large number of people.

11. The minimum that enthusiasts managed to squeeze out of the Prius is 1.73 liters per 100 kilometers in urban mode. For this, the tire pressure was raised to 5 atmospheres.

12. Large trunk with easy access. Under the floor there is a stowaway and a fairly spacious drawer for small items. On the sides are huge niches between the rear lights and wheel arches.

13. Inside, the Prius resembles an airliner. Interior trim is made of hard plastic, but with a very pleasant texture. Due to the strong slope of the windshield, the interior seems large and spacious.

14. On the steering wheel touch buttons with duplication of information on the central display. Instead of a gear knob - a non-fixed joystick. "Parking" is activated by a button (in the background). When driving, you can use two modes: D - normal drive, B - engine braking mode, mainly needed for driving on descents in mountainous areas and additional fuel savings if used correctly.

15. On the left in the corner - the control buttons for the projection screen on the windshield (it is shown in the video below). The air conditioning system does not have a division into zones, but uses a fully electric air conditioner. As an option, it is possible to start the interior cooling remotely from the key fob (not in this configuration). Learn more about the media system. Navigation coverage is so-so - Russia does not exist in principle beyond the Urals to the East. The most interesting thing is that this is the first full-time media system that supports the ability to receive music via bluetooth from mobile devices using the A2DP protocol (while ordinary radio tape recorders learned how to do this 5 years ago). By the way - the audio system sounds much better than you expect from it. Below are three hybrid control buttons. In all-electric mode, acceleration is very smooth and you can move at a speed of no more than 50 km / h. On a fully charged battery, you can drive about 1-1.5 kilometers. "Eco" and "Power" modes just change the sensitivity of the gas pedal, setting the driver for a calmer, or vice versa, more sporty driving style.

16. The Ready indicator indicates that the car is “started”, while the gasoline engine in the parking lot will only start if the battery is heavily discharged. There is no tachometer, its place is taken by an economizer, which suggests the optimal driving mode with minimal fuel consumption. Fuel consumption of more than 10 liters for a Prius from the realm of fantasy (conditionally).

17. Salon is especially interesting in detail. The two-compartment glove compartment is very reminiscent of similar luggage boxes on airplanes. With a smooth opening and a characteristic click when closing.

18. Some screens of the media system.

19. And display options on the central display. Two round images duplicate the corresponding buttons on the steering wheel and are activated when touched. On the right are several screens: an energy monitor showing where the energy is going between the motors, wheels and battery; an indicator of the operation of a hybrid installation, so to speak, an advanced economizer; as well as graphs of fuel consumption for the past intervals and the last 5 minutes (real-time operation can be seen in the video below).

21. The dynamics of the car is easiest to compare with a trolleybus. Smooth and constant acceleration from any speed. Acceleration to 100 km / h - 11.5 seconds (according to the passport 10.5 seconds). Feels like a C-class car with a two-liter gasoline engine and an automatic transmission. Dynamics is enough for safe movement.

23. The central tunnel is excellent. The right hand rests very comfortably on top of it. But why were the seat heating buttons placed in this niche, next to the cigarette lighter socket? It's so inconvenient to reach out to turn it on.

24. Multifunctional armrest - slides back to turn into a cup holder, or lifts up to access the drawer. The function of closing the air ducts is very cool, without complicating the structure with unnecessary elements. Turning on the recirculation mode with a button on the steering wheel, Toyota engineers clearly spied on BMW, but the temperature change buttons are clearly superfluous and useless.

25. The back is spacious, but very boring. Of the features of the front seats - the back of the driver's seat does not have a smooth tilt adjustment, and at the same time cannot be fixed in a strictly vertical position.

26. Light gray perforated leather does not seem expensive at all, but it is very practical. Next to the right rear seat is a battery vent grille - according to the instructions, it must not be covered with anything. It's great to sit in the back together, but the three of us will be cramped.

27. View back closes the glass divider with a spoiler. The lower glass is tinted. For me, the biggest mystery remains - why is the rear wiper here? Its cleaning zone is exclusively the upper part of the glass, through which nothing can be seen anyway. There is no parking sensors, it is replaced by a rear view camera. In addition, there is an automatic parking function, its operation is shown in the video (hereinafter).

28. Talking about the intricacies of handling with tires of this dimension is simply pointless. But in fact, not everything is as bad as it might seem at first glance. The electric power steering clearly increases steering effort as speed increases, and the suspension keeps the wheels from losing traction. The long base has a very positive effect on stability and comfort when driving on the highway.

29. The braking system deserves a separate review. Pressing the brake pedal first switches the hybrid powertrain to energy recovery mode. Thus, most of the energy that in a conventional car goes into heating the brake pads and discs is converted into electricity, which is stored in the battery. With a stronger pressure on the brake pedal, the standard brake system additionally starts to work. In this regard, the operation of the anti-lock braking system (ABS) and the dynamic stabilization system have been significantly changed. ABS allows heavy braking with full wheel locks and will turn on only after the car has been slipping with the wheels locked for some distance.

30. On-board computer displays the consumption scale at five-minute intervals. Small cars - accumulated bonuses for the effective use of the hybrid installation, they can be "collected" by braking.

I did a little research to find out the actual fuel consumption. When driving on cruise control on a relatively flat track without elevation changes, the following values were obtained:

Speed 60 km/h - 3 l/100 km
Speed 70 km/h - 3.5 l/100 km
Speed 90 km/h - 4.5 l/100 km
Speed 120 km/h - 6.5 l/100 km
Speed 135 km/h - 7.5 l/100 km

Of course, in this mode, the hybrid installation does not work as intended and consumption is actually determined by the fuel efficiency of the gasoline engine and the drag coefficient (for speeds of 90 km/h and above). Any modern turbodiesel on the track will show comparable consumption figures (eg BMW 123d).

Tests in Moscow traffic jams showed more interesting figures. If you drive calmly at a flow rate, stand in traffic jams (it doesn’t matter which ones - the gasoline engine turns off at stops, so you can stand still for at least a few hours with zero fuel consumption) and don’t think about fuel economy at all, you will get a consumption of 5.5-6 liters per 100 kilometers. If you drive dynamically, with frequent accelerations, then it will be extremely difficult to get an average consumption of more than 7.5-8 liters per 100 kilometers. The most important thing is not to forget to slow down to recharge the battery.

It will be assumed that the average annual mileage of a typical car owner is 30 thousand kilometers. An ordinary car of comparable power (a 2-liter gasoline engine with automatic transmission) in a combined cycle with a predominance of city traffic in traffic jams will consume 10 liters per 100 kilometers. Prius in similar conditions will show a consumption of about 6 liters per 100 km. If we assume that the cost of one liter of 95th gasoline is 25 rubles, then the annual savings when using the Prius will be only 30 thousand rubles.

It should be noted that in pursuit of minimum consumption, one should also take into account the wind, type of road surface, air temperature, and tire pressure. All tests were carried out at a temperature of +5 degrees on winter studded tires with a pressure of 2.5 atm.

The video shows the operation of the parking assistance system. An extremely useless option, which, in addition to turning the steering wheel, can do nothing else, and always requires support from the driver. I filmed only perpendicular parking, because I didn’t have enough strength to fulfill all the conditions of the system for parallel parking so that it would not turn off ahead of time (you can’t press the gas, you need to hold the brake, the car can’t drive up a small hill without gas, the system doesn’t “see” the potential parking space). Pay attention to the nasty squeak when the reverse gear is engaged, which cannot be turned off! In addition, the operation of the projection of the speedometer and economizer on the windshield is shown (the navigation system prompts are also displayed there), an episode of acceleration from standstill to 100 km / h (I want to note right away that the overtaking car in the left lane did not slow down at the traffic lights and already had a speed at the time start Prius) and a screen showing the modes of operation of the hybrid power plant.

32. The Prius is delivered to Russia in two trim levels: Elegance for 1.1 million rubles and Prestige for 1.35 million rubles. The main difference between the trim levels: LED dipped beam, navigation, leather interior, rain and light sensors, climate control and bluetooth.

The Prius is beautiful in its uniqueness. It attracts the attention of others, it is comfortable and reliable, as a Toyota car should be. It is as technologically advanced as possible and stuffed with all modern electronic systems to the eyeballs (up to the option in the form of solar panels on the roof that feed the air conditioning system so that the air in the cabin does not stagnate in the parking lot, but such equipment is not brought to Russia). The only problem with buying a Prius in Russia is that our government does not encourage the purchase of environmentally friendly and economical cars, as is done in civilized countries. And yet our society does not think about environmental problems in principle. And even conscious people understand that their personal contribution to caring for the environment will not be noticeable against the backdrop of the trash that drives on our roads, not meeting any environmental standards.

In any case, this is a great car for city traffic. Buying a Prius is primarily a fashion thing and a reason to be proud that you are the owner of a high-tech and environmentally friendly car. But don't be surprised if society doesn't understand your choice.

Toyota Prius Vehicle operation in various driving modes

Comparative data of Prius cars of various years of manufacture

Internal combustion engine Toyota Prius

Toyota Prius has an internal combustion engine (ICE) with a displacement of 1497 cc, which is unusually small for a car weighing 1300 kg. This is made possible due to the presence of electric motors and batteries that help the ICE when more power is needed. In a conventional car, the engine is designed for high acceleration and driving up a steep hill, so it almost always runs at low efficiency.The 30th body uses a different engine, 2ZR-FXE, 1.8 liter.Because the car can not be connected to the city network power supply (which is planned to be implemented by Japanese engineers in the near future), there is no other long-term source of energy and this engine must supply energy to charge the battery, as well as to move the car and power additional consumers such as air conditioning, electric heater, audio, etc. .e Toyota designation for engine Prius - 1NZ-FXE. The prototype of this engine is the 1NZ-FE engine, which was installed on Yaris, Bb, Fun Cargo", Platz cars. The design of many parts of the 1NZ-FE and 1NZ-FXE engines is the same. For example, cylinder blocks for Bb, Fun Cargo, Platz and Prius 11 However, the 1NZ-FXE engine uses a different carburetion scheme, and therefore the design differences are associated.The 1NZ-FXE engine uses the Atkinson cycle, while the 1NZ-FE engine uses the conventional Otto cycle.

In an Otto cycle engine, during the intake process, an air-fuel mixture enters the cylinder. However, the pressure in the intake manifold is lower than in the cylinder (because the flow is controlled by the throttle), and so the piston does the extra work of sucking in the air-fuel mixture, acting as a compressor. The intake valve closes near bottom dead center. The mixture in the cylinder is compressed and ignited at the moment the spark is applied. In contrast, the Atkinson cycle does not close the intake valve at bottom dead center, but leaves it open while the piston begins to rise. Part of the air-fuel mixture is forced into the intake manifold and used in another cylinder. Thus, pumping losses are reduced compared to the Otto cycle. Since the volume of the mixture that compresses and burns is reduced, the pressure during compression with this mixture formation scheme also decreases, which makes it possible to increase the compression ratio to 13, without the risk of detonation. Increasing the compression ratio increases the thermal efficiency. All these measures contribute to improving the fuel efficiency and environmental friendliness of the engine. The payoff is a reduction in engine power. So the 1NZ-FE engine has a power of 109 hp, and the 1NZ-FXE engine has 77 hp.

Engine/Generators Toyota Prius

Toyota Prius has two electric motors/generators. They are very similar in design, but differ in size. Both are three-phase permanent magnet synchronous motors. The name is more complex than the design itself. The rotor (the part that rotates) is a large, powerful magnet and does not have any electrical connections. The stator (the fixed part attached to the car body) contains three sets of windings. When current flows in a certain direction through one set of windings, the rotor (magnet) interacts with the magnetic field of the winding and is set in a certain position. By passing current in series through each set of windings, first in one direction and then in the other, the rotor can be moved from one position to the next, and so make it rotate. Of course, this is a simplified explanation, but it shows the essence of this type of engine. If an external force turns the rotor, the current flows through each set of windings in turn and can be used to charge a battery or power another motor. Thus, one device can be a motor or a generator depending on whether current is passed through the windings to attract the rotor magnets, or current is released when some external force turns the rotor. This is even more simplified, but will serve the depth of the explanation.

Toyota Prius Inverter

Since motors/generators run on AC three-phase current, and the battery, like all batteries, produces direct current, some device is needed to convert one form of current to another. Each MG has an "inverter" that performs this function. The inverter learns the position of the rotor from a sensor on the MG shaft and controls the current in the motor windings to keep the motor running at the required speed and torque. The inverter changes the current in a winding when the magnetic pole of the rotor passes that winding and moves on to the next one. In addition, the inverter applies battery voltage to the windings and then switches it off again very quickly (at a high frequency) in order to change the average current value and hence the torque. By exploiting the "self-inductance" of the motor windings (a property of electrical coils that resist changing current), the inverter can actually push more current through the winding than is supplied by the battery. It only works when the voltage across the windings is less than the battery voltage, hence energy is saved. However, since the amount of current through the winding determines the torque, this current makes it possible to achieve very high torque at low speeds. Up to approximately 11 km/h, the MG2 is capable of generating 350 Nm (400 Nm for the Prius NHW-20) of torque at the gearbox. That is why the car can start moving with acceptable acceleration without the use of a gearbox, which usually increases the torque of the internal combustion engine. In the event of a short circuit or overheating, the inverter switches off the high voltage part of the machine. In the same unit with the inverter, there is also a converter, which is designed to reverse convert AC voltage to DC -13.8 volts. To deviate a little from theory, a bit of practice: the inverter, like motor-generators, is cooled by an independent cooling system. This cooling system is powered by an electric pump. If on body 10 this pump turns on when the temperature in the hybrid cooling circuit reaches about 48 ° C, then on bodies 11 and 20 a different algorithm for the operation of this pump is used: be “overboard” at least -40 degrees, the pump will still start its work already at turning on the ignition. Accordingly, the resource of these pumps is very, very limited. What happens when a pump jams or burns out: according to the laws of physics, antifreeze under heating from MG (especially MG2) rises up - into the inverter. And in the inverter, it must cool the power transistors, which heat up significantly under load. The result is their failure, i.e. the most common error on body 11: P3125 - inverter malfunction due to a burnt out pump. If in this case the power transistors withstand such a test, then the MG2 winding burns out. This is another common error on body 11: P3109. On the 20th body, Japanese engineers improved the pump: now the rotor (impeller) does not rotate in a horizontal plane, where the entire load goes to one support bearing, but in a vertical one, where the load is distributed evenly over 2 bearings. Unfortunately, this added little reliability. In April-May 2009 alone, 6 pumps on 20 bodies were replaced in our workshop. Practical advice for owners of 11 and 20 Prius: make it a rule at least once every 2-3 days to open the hood for 15-20 seconds with the ignition on or the car running. You will immediately see the movement of antifreeze in the expansion tank of the hybrid system. After that, you can drive safely. If there is no antifreeze movement there, you can’t drive a car!

Toyota Prius high voltage battery

high voltage battery(abbreviated VVB Toyota Prius) Prius in 10 body consists of 240 cells with a nominal voltage of 1.2 V, very similar to a D-size flashlight battery, combined in 6 pieces, into the so-called "bamboos" (there is a slight resemblance in appearance). "Bamboos" are installed in 20 pieces in 2 buildings. The total nominal voltage of the VVB is 288 V. The operating voltage fluctuates in idle mode from 320 to 340 V. When the voltage drops to 288 V in the VVB, starting the internal combustion engine becomes impossible. In this case, the battery symbol with the "288" icon inside will light up on the display screen. To start the internal combustion engine, the Japanese in the 10th body used a regular charger, which is accessed from the trunk. Frequently asked questions, how to use it? I answer: firstly, I repeat that it can only be used when the "288" icon is on the display. Otherwise, when you press the "START" button, you will simply hear a nasty squeak, and the red "error" light will light up. Secondly: you need to hook up a “donor” to the terminals of a small battery, i.e. either a charger or a well-charged powerful battery (but by no means a starting device!). After that, with the ignition OFF, press the "START" button for at least 3 seconds. When the green light turns on, the VVB will start charging. It will end automatically after 1-5 minutes. This charge is quite enough for 2-3 starts of the internal combustion engine, after which the VVB will be charged from the converter. If 2-3 starts did not lead to the start of the internal combustion engine (and at the same time "READY" ("Ready") on the display should not blink, but burn steadily), then it is necessary to stop useless starts and look for the cause of the malfunction. In the 11th body, the VVB consists of 228 elements of 1.2 V each, combined in 38 assemblies of 6 elements, with a total nominal voltage of 273.6 V.

The entire battery is installed behind the rear seat. At the same time, the elements are no longer orange "bamboos", but are flat modules in gray plastic cases. The maximum battery current is 80 A when discharging and 50 A when charging. The nominal capacity of the battery is 6.5 Ah, however, the car's electronics allow only 40% of this capacity to be used in order to prolong the life of the battery. The state of charge can only change between 35% and 90% of the full rated charge. Multiplying the battery voltage and its capacity, we get the nominal energy reserve - 6.4 MJ (megajoules), and the usable reserve - 2.56 MJ. This energy is enough to accelerate the car, driver and passenger to 108 km / h (without the help of the internal combustion engine) four times. To produce this amount of energy, an internal combustion engine would require approximately 230 milliliters of gasoline. (These figures are only given to give you an idea of the amount of stored energy in the battery.) The vehicle cannot be driven without fuel, even when starting at 90% full rated charge on a long descent. Most of the time you have about 1 MJ of usable battery power. A lot of VVB gets into repair precisely after the owner runs out of gas (in this case, the "Check Engine" icon and a triangle with an exclamation mark will light up on the scoreboard), but the owner tries to "reach out" to refueling. After the voltage drops on the elements below 3 V, they "die". On the 20th body, Japanese engineers went the other way to increase power: they reduced the number of elements to 168, i.e. left 28 modules. But for use in an inverter, the battery voltage is raised to 500 V using a special -booster device. An increase in the nominal voltage of MG2 in the NHW-20 body made it possible to increase its power to 50 kW without changing the dimensions.

The Prius also has an auxiliary battery. This is a 12-volt, 28 amp-hour lead-acid battery, which is located on the left side of the trunk (in the 20 body - on the right). Its purpose is to energize the electronics and accessories when the hybrid system is off and the main high voltage battery relay is off. When the hybrid system is running, the 12V source is a DC/DC converter from the high voltage system to 12V DC. It also recharges the auxiliary battery when needed. The main control units communicate via the internal CAN bus. The remaining systems communicate over the Body Electronics Area Network. The VVB also has its own control unit, which monitors the temperature of the elements, the voltage on them, the internal resistance, and also controls the fan built into the VVB. On the 10th body there are 8 temperature sensors, which are thermistors, on the "bamboos" themselves, and 1 is a common VVB air temperature control sensor. On the 11th body -4 +1, and on the 20th -3 +1.

Toyota Prius power distribution unit

Usually the most asked question about the "box" of a Prius car: what kind of oil is poured there, how much in volume and how often to change it. Very often, there is such a misconception among car service workers: since there is no dipstick in the bark, it means that the oil does not need to be changed there at all. This misconception has led to the death of more than one box.

10 body: working fluid T-4 - 3.8 liters.

11 body: working fluid T-4 - 4.6 liters.

20 body: ATF WS working fluid - 3.8 liters. Replacement period: after 40 thousand km. According to Japanese terms, oil is changed every 80 thousand km, but for especially difficult operating conditions (and the Japanese attribute the operation of cars in Russia to these especially difficult conditions - and we are in solidarity with them), the oil is supposed to be changed 2 times more often.

I will tell you about the main differences in the maintenance of the boxes, i.e. about changing the oil. If in the 20th body, in order to change the oil, you just need to unscrew the drain plug and, having drained the old one, fill in new oil, then on the 10th and 11th bodies it is not so simple. The design of the oil pan on these machines is made in such a way that if you simply unscrew the drain plug, then only part of the oil will drain, and not the dirtiest. And 300-400 grams of the dirtiest oil with other debris (pieces of sealant, wear products) remains in the sump. Therefore, in order to change the oil, it is necessary to remove the box pan and, having poured out the dirt and cleaned it, put it in place. When removing the pallet, we get another additional bonus - we can diagnose the condition of the box by the wear products in the pallet. The worst thing for the owner is when he sees yellow (bronze) chips at the bottom of the pan. This box does not have long to live. The pan gasket is cork, and if the holes on it have not acquired an oval shape, it can be reused without any sealants! The main thing when installing the pallet is not to overtighten the bolts so as not to cut the gasket with the pallet. What else is interesting in the transmission: The use of a chain drive is quite unusual, but all ordinary cars have gear reductions between the engine and the axles. Their purpose is to allow the engine to spin faster than the wheels and also increase the engine generated torque to more torque at the wheels. The ratios with which rotational speed is reduced and torque increased are necessarily the same (neglect friction) due to the law of conservation of energy. The ratio is called the "total gear ratio". The total gear ratio of the Prius in the 11th body is 3.905. It turns out like this:

The 39-tooth sprocket on the PSD output shaft drives the 36-tooth sprocket on the first intermediate shaft through a silent chain (so-called Morse chain).

The 30-tooth gear on the first countershaft is connected to and drives the 44-tooth gear on the second countershaft.

The 26-tooth gear on the second countershaft is connected to and drives the 75-tooth gear at the differential input.

The value of the output of the differential to the two wheels is the same as the input of the differential (they are, in fact, identical, except when cornering occurs).

If we perform a simple arithmetic operation: (36/39) * (44/30) * (75/26), we get (to four significant digits) a total gear ratio of 3.905.

Why is a chain drive used? Because it avoids the axial force (force along the axis of the shaft) that would occur with conventional helical gears used in automotive transmissions. This could also be avoided with spur gears, but they produce noise. Thrust is not a problem on the intermediate shafts and can be balanced by tapered roller bearings. However, this is not so easy with the PSD output shaft. There is nothing very unusual about a Prius differential, axles and wheels. As in a conventional car, the differential allows the inner and outer wheels to spin at different speeds when the car turns. The axles transmit torque from the differential to the wheel hub and include an articulation to allow the wheels to move up and down following the suspension. The wheels are lightweight aluminum alloy and fitted with high pressure tires with low rolling resistance. The tires have a rolling radius of approximately 11.1 inches, which means the car moves 1.77 meters for each revolution of the wheel. Only the size of stock tires on 10 and 11 bodies is unusual: 165/65-15. This is a rather rare tire size in Russia. Many sellers, even in specialized stores, quite seriously convince that such rubber does not exist in nature. My recommendations: for Russian conditions, the most suitable size is 185/60-15. In the 20 Prius, the size of the rubber has been increased, which has a beneficial effect on its durability. Now more interesting: what is missing in the Prius, what is in any other car?

There is no stepped transmission, either manual or automatic - the Prius does not use stepped transmissions;

There is no clutch or transformer - the wheels are always hardwired to the ICE and motors/generators;

There is no starter - starting the internal combustion engine is done by MG1 through gears in the power distribution device;

There is no alternator - electricity is generated by motors/generators as needed.

Vehicle operation in various driving conditions

Toyota Prius engine start

Cold start Toyota Prius

When you start a Prius with a cold engine, its top priority is to warm up the engine and catalytic converter so that the emission control system can work. The engine will run for several minutes until this happens (how long depends on the actual temperature of the engine and catalytic converter). At this time, special measures are taken to control the exhaust during warm-up, including keeping the exhaust hydrocarbons in the absorber, which will be cleaned later and running the engine in a special mode.

Warm start Toyota Prius s

When you start a Prius with a warm engine, it will run for a short time and then stop. Idling will be within 1000 rpm.

Unfortunately, it is not possible to prevent the internal combustion engine from starting when you turn on the car, even if all you want to do is move to a nearby lift. This only applies to 10 and 11 bodies. On the 20th body, a different start algorithm is applied: press the brake and the "START" button. If there is enough energy in the VVB, and you do not turn on the heater to heat the interior or glass, the internal combustion engine will not start. The inscription "READY" (Totob ") will just light up, i.e. the car is COMPLETELY ready to move. It is enough to switch the joystick (and the choice of modes on the body 20 is done with the joystick) to position D or R and release the brake, you will go!

Now we have to find out how the 28% of the ICE torque that is sent to the MG1 generator can possibly boost the start of the car - with the help of the MG2 motor. To do this, we must clearly distinguish between torque and energy. Torque is a rotating force, and just like a straight line force, no energy is required to maintain the force. Suppose you are pulling a bucket of water with a winch. She takes energy. If the winch is driven by an electric motor, you would have to supply it with electricity. But, when you have raised the bucket to the top, you can hook it with some kind of hook or rod or something else to keep it on top. The force (weight of the bucket) that is applied to the rope and the torque transmitted by the rope to the winch drum has not disappeared. But because the force does not move, there is no transfer of energy, and the situation is stable without energy. Likewise, when the vehicle is stationary, even though 72% of the ICE's torque is being sent to the wheels, there is no energy flow in that direction since the ring gear is not rotating. The sun gear, however, rotates quickly, and although it receives only 28% of the torque, this allows a lot of electricity to be generated. This line of reasoning shows that MG2's task is to apply torque to the input of a mechanical gearbox that does not require much power. A lot of current must pass through the motor windings, overcoming electrical resistance, and this energy is wasted as heat. But when the car is moving slowly, this energy comes from MG1. As the vehicle starts to move and picks up speed, MG1 rotates more slowly and produces less power. However, the computer may increase the speed of the internal combustion engine a little. Now more torque is coming from the ICE and since more torque must also go through the sun gear, MG1 can keep the power generation high. The reduced rotational speed is compensated by an increase in torque.

Accelerating and driving uphill Toyota Prius

So, the internal combustion engine rotates the carrier of the satellites of the planetary mechanism.

72% of its torque is sent mechanically through the ring gear to the wheels.

On the other hand, if the required power is not so high, iu part of the electricity produced by MG1 can be used to charge the battery even when accelerating! It is important to remember that the ICE both turns the wheels mechanically and turns the MG1 generator, causing it to produce electricity. What happens to this electricity and whether more battery electricity is added depends on a complex of reasons that we cannot all account for. This is handled by the vehicle's hybrid system controller.

Note that the high vehicle speed and low ICE RPM put the power distribution device in an interesting position: MG1 should now be spinning backwards, as you can see from the table. Rotating backward, it causes the satellites to rotate forward. The rotation of the planets adds to the rotation of the carrier (from the internal combustion engine) and causes the ring gear to rotate much faster. Once again, the difference is that in the earlier case, we were happy to get more power with the help of high engine speeds, even moving at a slower speed. In the new case, we want the ICE to stay at a low RPM even if we have accelerated to a decent speed in order to set a lower power draw with high efficiency. We know from the section on power distribution devices that MG1 must reverse torque on the sun gear. This is, as it were, the fulcrum of the lever, with the help of which the internal combustion engine rotates the ring gear (and hence the wheels). Without MG1 drag, the ICE would simply spin MG1 instead of propelling the car. When MG1 rotated forward, it was easy to see that this reverse torque could be generated by the generator load. Therefore, the inverter electronics had to take power from MG1, and then reverse torque appeared. But now MG1 is spinning backwards, so how do we get it to generate this reverse torque? Ok, how would we make MG1 spin forward and produce straight torque? If only it worked like a motor! The opposite is true: if MG1 is rotating backwards and we want to get torque in the same direction, MG1 must be the motor and rotate using the electricity supplied by the inverter. It's starting to look exotic. ICE pushes, MG1 pushes, MG2, what, pushes too? There is no mechanical reason why this cannot happen. It may look attractive at first sight. The two engines and the internal combustion engine all contribute to the creation of the movement at the same time. But, we must recall that we got into this situation by reducing the speed of the internal combustion engine for efficiency. It wouldn't be an efficient way to get more power to the wheels; to do this, we must increase the ICE RPM and return to the earlier situation where MG1 is spinning forward in generator mode. There is one more problem: we have to figure out where we are going to get energy to rotate MG1 in motor mode? From a battery? We can do this for a while, but soon we will be forced to exit this mode, left without battery power to accelerate or climb the mountain. No, we must receive this energy continuously, without allowing the battery to run low. Thus, we came to the conclusion that the energy should come from MG2, which should work as a generator. Does generator MG2 produce power for motor MG1? Since both the ICE and MG1 contribute power that is combined by a planetary gear, the name "power combining mode" has been suggested. However, the idea of MG2 producing power for the MG1 motor was so at odds with people's ideas about how the system would work that a name was coined that has become generally accepted - "Heretical Mode". Let's go over it again and change our point of view. The internal combustion engine rotates the planet carrier at low speed. MG1 rotates the sun gear backwards. This causes the planets to rotate forward and adds more rotation to the ring gear. The crown gear still only receives 72% of the ICE torque, but the speed at which the ring rotates is increased by moving the MG1 motor backwards. Rotating the crown faster allows the car to go faster at low engine speeds. MG2, unbelievably, resists the car's movement like a generator, and produces electricity that powers MG1's motor. The car is propelled forward by the remaining mechanical torque from the internal combustion engine.