What motors are used in electric vehicles. Modern electric motor. The structure and principle of work.

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From the very moment of the appearance of factories and waste from them, mankind began to worry about the environment. This served as a branch for a whole new science that looked for analog power sources. Electricity became such a source. It can be produced in an absolutely environmentally friendly way - with the help of turbines driven by water, wind and even sunlight.

The same situation happened with the car. People have been trying to make an electric car for a long time. But there was always some kind of deterrent. The most important thing was the lack of a suitable power source. But not so long ago, the world saw the first version of SMART - a smart car powered by electricity, which was distributed throughout the car in a specific pattern.

Its characteristics could compete with cars on the internal combustion engine. At that moment, the entire community was divided into two camps - those who predicted a great future for Smart and those who argued that this idea would be crushed by the oil tycoons. Indeed, the development of this automotive industry has progressed too slowly.

This situation persisted until recently. Tesla released its first electric car, it was sporty and not widely used. And then they decided to launch a mass electric car on the market. And it was then that their company began to flourish. And now, after a short course in history, let's figure out what kind of beast it is - an electric car, what kind of device it has, what it consists of, and what characteristics are worth paying attention to.

Electric vehicle structure

An electric car has a fairly simple structure:

• body;
• suspension;
• electric motors (we will talk about their types later);
• battery.

This is where the design of an electric car ends. Yes, it contains a huge number of electronic devices connected according to a certain scheme, an air conditioner and everything else. But the main parts are listed above. In fact, this is the same car from which the engineers threw out all the propulsion and fuel system... That is, there is no gas tank or gas cylinders. But the most important thing is different - there is no air filters, engine and exhaust system... This significantly improves the acceleration and some other characteristics of the car. And what is there? and how does such a car generally go?

Propulsion system

In order to understand how an electric car drives, you first need to understand the types of electric motors and their characteristics:

• electric motors alternating current;
• electric motors direct current.

As you remember from your high school physics course, an alternating current is created using a huge magnetic core that rotates inside a ferromagnetic casing. Each time the magnet makes one complete revolution, the direction of the electric flow in the circuit changes. And this is called alternating current.

And if electricity flows in one direction according to the scheme, then such a current is called constant. The most obvious example of such schemes is accumulators and batteries, which are installed in alarm clocks, smartphones, control panels, and so on.

At first, there were attempts to make a car on an electric AC motor. But then the loss of electricity was simply catastrophic. In addition, a generator for changing the direction of the current had to be inserted into the car. And this is a loss of precious space and an increase in the weight of the car. Such characteristics of the car did not suit the designers. As a result, it was decided to proceed from the use of direct current.

Ultimately, a huge DC battery was placed under the car, and a DC electric motor was connected to each of the four wheels. The circuit was extremely simple, and therefore it worked. There are a couple of issues left to solve: cooling, current distribution, and a few others.

All motors are controlled by a single computer that regulates the power of the electric flow, and, accordingly, the speed of rotation of the wheels. And earlier the electric engine was one and was located under the hood. But later it was decided to use four different engine attached directly to the suspension right next to the wheels.

In this mode, the haste ability is sacrificed to the radius. If the driver is in an area where the car needs to climb steep degrees, the range selector can be set so that the maximum current power of the engine controller and engine can be used. The ranging function is a valuable feature that improves the efficiency of the motor controller. The ultimate goal of the control system is to maximize the energy stored in the traction battery and prevent unsafe conditions inside the vehicle.

Therefore, an unprepared driver with great experience can experience the shock of contemplating the separation of the hood, there is a full luggage compartment, and not the usual "giblets" of a car with an internal combustion engine.

Batteries

By the way, another interesting point is the batteries. It is their characteristics that determine how much a car can travel on a single charge. They here, as a rule, consist of a set of ordinary batteries, which are used in laptops, electronic cigarettes, and so on. Their connection scheme is such that at the output we get enough power to spin up the engine and sufficient capacity to drive the maximum distances. To ensure that the battery does not discharge immediately, a special device is responsible - a charge and discharge controller.

Cooling

Another problem is the cooling system for the battery. As you know, when working, he, and all electronic circuit, it gets pretty hot. And when heated, lithium-ion batteries give off a certain amount of gas. The more it comes out, the worse performance devices. Accordingly, overheating should not be allowed. Therefore, a reasonable cooling system must be used. Everyone does their own thing. Someone is doing a complicated oil or water system cooling, and someone simply positions the battery so that it is constantly blown with air. The last move allows you to abandon cooling systems in principle.

In addition, the wires through which the current flows, as well as all other electrical and electronic parts, heat up. If you do not take care of high-quality cooling, then in the summer it is simply impossible to drive in such a car. Therefore, car cooling is another scourge that pursues electric vehicles.

Engine types

Let's see what else you need to know about the device and on electric cars. So, here are the types of electric motors that are installed on modern electric vehicles:

Voltage type

• Permanent. Its use is more rational, since with constant current its waste is significantly reduced.
• Variable (after all, some people manage to put them).

Number of phases

• single-phase (one winding around the core);
• two-phase (two windings: one wraps around the core from below and from above, the second - to the left and right);
• three-phase (three windings are used here, which are located with a lag of 120 degrees from each other).

Design

• Collector. You met with them in grinders, drills and so on. They are characterized by the presence of brushes. Quite unreliable.
• Brushless. Here the core is in a constant magnetic field and does not touch the stator walls. Found in aquarium compressors and individual heating systems. They are more reliable.

Principle of operation

The scheme of work can be as follows:

• Synchronous motor. The running speed of the magnetic flux in the winding is equal to the rotor speed.
• Asynchronous. Here the rotor rotates at a different speed than the magnetic flux flows.

Advantages and disadvantages of electric vehicles over cars with internal combustion engines

Let's start with the benefits:

1. Environmental friendliness (for many, the ability to leave their children a clean planet is above all else).
2. Durability.
3. Easy to use.

No torque limit. It reaches its peak from the very first revolution. Therefore, the overclocking characteristics here are simply frantic.

1. Excellent efficiency.
2. No gearbox needed.
3. The electric motors themselves for electric vehicles are very small in size. Some copies are located directly in the wheel. This system is called a motor-wheel.

1. There are difficulties in the feeding elements. Until scientists invent innovative energy banks, electrically powered cars will cost and weigh a lot because of the batteries.

For example, it weighs about 700 kg in a Tesla car. And this is with a power reserve of 350 km.

1. This disadvantage applies specifically to Russia and neighboring countries. It is unlikely that soon we will have extensive networks of filling stations for electric cars, so buying this car is justified only when you are constantly in the metropolis.
2. Cooling. If it is insufficient, then the battery life will not be too long. Therefore, when choosing a car, you should pay special attention to the cooling system.

Conclusion

As we can see, the device of an electric vehicle is quite complex. Engineers are trying to provide these cars with all sorts of innovations, as well as extend the power reserve. We can only wait for perfect technologies and admire them.

› Conversion of cars to electro! Choice of motor and controller!

By far the most expensive part of an EV is the battery!
And as described in the last article, the range depends on the battery capacity, but
and a lot also depends on the efficiency of the engine and the energy consumed by it per 1 km!
In terms of cost, the duo of motor and controller ranks second after battery!

What kind of engines can you drive?
In fact, there are 3 types of them!
1. DC motor of mixed, series or parallel excitation (DC);
2. DC motors with permanent magnets or also called without brush (BLDC);
3. AC motors asynchronous with copper or aluminum squirrel cage rotor (AC);

The most budgetary set of these three is option 1. As a rule, it consists of a used or a new traction engine from a Bulgarian-made Balkankar loader or well-proven engines of the DS-3.6 and DS-6.3 brands. Many auto conversions began with the fact that such an engine was tucked into a person, and with it the idea of ​​switching to electric traction. The price of such an engine, depending on the state, can be different, but on average it is about 400 USD. There are American monsters such as Varp and Advanced, starting at $ 700. and higher! It is not difficult to pick up a counterler for it, many dare to solder them at home. Of those widely used in our country, these are Kelly, Comet and the so-called Controller from "Romantic" (Yuri Logvin, Romantic - a nickname on the electric car forum). The price of such controllers is also not high, from 300 to 500 USD. For American monsters Varp and Advanced, a high power controller can cost up to $ 2000. Advantages of a propulsion system with a DC motor sequential excitation which was discussed above, undoubtedly the price and high overload capacity, i.e. with a rated power of 3.6 kW, the motor can produce 3-5 times more if necessary! Depending on the power of the controller used. Minus the absence or complexity of organizing the recuperation process (the property of the engine becomes a generator and charge the battery during braking or driving downhill) relatively low efficiency of 75-85% at rated speed. Engines with parallel excitation among homemade products were less widespread, but they were equipped with serial Renault and Citroen Saxo electric vehicles. These machines can be bought relatively inexpensively at secondary market in Germany, it only remains to complete the battery.

Option 2 More expensive than the previous one, as a rule, it is sold by a pair of engine + controller, (on average, about 1.5 thousand cu) has a high efficiency of more than 90%, but has a low overload capacity, if we take the minimum design power of 6 kW per 1 ton curb weight, then for option 1, 3.6 kW is enough for option 2 - 10-12 kW. Recovery on such a set is organized without problems and is most often present as a standard controller option.

Option 3 is the most expensive! Most progressive! It has one drawback - the Price! But how many pluses ?!
Suffice it to say that an induction motor with a copper rotor is equipped with Tesla car model S!
But not everything is so sad! For conversion, you can use the usual general industrial asynchronous motor, let's say AIR112MB8! But the stator windings will need to be rewound in a special way. The type of such a winding is called "Slavyanka" such a name was given to it by its developers, our compatriots. This type of winding allows you to get an excellent traction motor from a conventional asynchronous motor, with energy consumption per km 30-40% lower than on DC motors! This means that with the same battery on the asynchronous circuit with the "Slavyanka" your mileage will be greater. The range of revolutions is up to 6000 and above. The controller for such an engine costs from 1.5 to 2.5 thousand cu. can be found on trading floors for 700-1000 USD. boo. mainly Curtis. Now such a controller is being actively developed by Russian scientists-enthusiasts! Perhaps the first small-scale samples will be ready by spring. They will be cheaper.

Let's summarize!

If you want to not expensively electrify a car up to 800 kg, look for a drive from a forklift! The engine weight must be at least 40-50 kg! It is important! An engine of 30 kg with a power of 6 kW will not have the required torque and will heat up to a critical 110 degrees! Also on the shield of the engine, its operating mode can be indicated - S1, S2, S3, S4. You need S1 or S2. The engine speed for the conversion with the gearbox must be comparable to the internal combustion engine, i.e. not less than 1800 revolutions. Their number can be increased by increasing the voltage from the nominal, say 48V to 72V. Choose a controller for the engine you have found!

If you want a compact motor with recuperation and not expensive, get the brushless motor plus controller kit! It is better to take the kit because this will simplify installation and ensure that the controller and motor are compatible and perform optimally.

If you decide to take the conversion seriously and want to get a car with excellent characteristics with recuperation and maximum speed for 100 km, then your choice is in favor of an asynchronous device with "Slavyanka"!
It is better to start such a conversion by finding and buying a controller! And already for the controller and its characteristics, select the engine.

These are the pies!

2 years

Comments 7

Hey! A lot of letters, Nov mastered!)
Where did you get the idea that Duyunov disclosed the winding data of the "Slav"?
For example, we have a license agreement with him for its use, and his patent right is protected by law. Everything is logical in your idea! Personally, I am confused by 2 points:
The quality of ensuring electrical safety when using hazardous voltages on serial samples.
The absolute unsuitability of industrial chastotniki for consumer use in transport.
What do you think?

In light of the fact that Mr. D. A. Duyunov revealed his secret of the combined winding of the Slavyanka type, we drew up a debugging block diagram of a hybrid vehicle with such an engine, since at low revs such an engine creates 4 times the torque, according to compared to a conventional induction motor.
Initially, it was assumed that it is better to wind the engine at a non-standard reduced voltage, in order to reduce the number of battery cells. However, having familiarized ourselves with the range and prices for low-voltage inverters, we came to the conclusion that it is more expedient to use an industrial inverter designed for power supply from a 3-phase AC 200 ... 240V - for medium-duty vehicles, and ~ 115V - for lighter applications. ...
An example of the first inverter can be VARISPEED CIMR-F7Z-2018 - 18kW,
the second - VACON0010-1L-0005-1-MACHINERY ~ 115V 1.1kW.
The diode bridge at the input of the inverter is excluded, the supply voltage from the batteries is supplied directly to the filter capacitor.
When using VFDs with vector control, you can abandon the gearbox - checkpoint.
Batteries can be used in different ways, each type has its own advantages and disadvantages. Lead-acid is the cheapest, but also the heaviest, but does not require balancing devices on each can. However, their most unpleasant drawback is the small number of charge-discharge cycles. Therefore, let's leave them in the past.
Nickel - metal - hydride is better, but in industrial hybrids they are now being abandoned in favor of LiFePO4.
This is the best option, the price for 1Ah is about 70… 80 rubles, unfortunately, balancing devices for 3.65V are required. However, their plus is that during the discharge cycle, the voltage across them remains more or less stable within 3.2V. Although, the operating range is considered to be 2.8 ... 3.65V.
LiIon and LiPo batteries are lighter with the same power, but their price is more than 100 rubles. for 1ah. Requires balancing devices on each 4.2V bank. In addition, they have a smaller number of charge-discharge cycles.
Thus, it is advisable to use one of the latest types of batteries: LiPo or LiFePO4, the latter will have a lower price, a little more weight, a slightly lower voltage spread, more charge-discharge cycles.
It should be noted that for a hybrid, a particularly large battery capacity is not needed. Their main function is a buffer between the generator and the inverter. During acceleration, energy is taken from the battery, while driving smoothly - from the generator, at the same time the battery is recharged for the next acceleration. The secondary function of the battery is to take energy into itself when braking by the engine - recuperation.
A lot of different devices can be used as a generator. These are standard generators that run on gasoline, diesel oil or gas. top scores should give linear (vibration) generators in which there is no crank mechanism, as a result, their efficiency increases. You can use an external combustion engine - Stirling, combined with a linear generator and heat the hybrid with wood)))

Let's take a hybrid Toyota car Prius NHW20.
The VVB high-voltage battery uses NiMH (nickel-metal hydride) batteries (cells) with a capacity of 6500 mAh and a nominal voltage of 7.2v.
Each cell consists of six "cans" with a voltage of 1.2v combined into one common package with two leads along the edges. There are 28 such cells in a high-voltage battery,
divided into 14 computer controlled pairs.
The total number of batteries is 6 * 28 = 168pcs. Average voltage 1.2 * 168 = 201.6V. Total power (6500mah / 1000) * 7.2V * 28pcs. = 1310.4 W.

We recalculate for LiPo and PiFePO4 batteries, taking into account that they will power an industrial inverter - VARISPEED F7.
Rated voltage - 3 phases, 200/220/230 / 240V + 10%, - 15%, 50/60 Hz
Consequently, the inverter remains operational with an alternating voltage at its input from 170 to 264 volts.
Constant - this is 170 * sqrt (2) = 240.4 minus the drop across the diodes of the bridge 239V
264 * sqrt (2) = 373.3 minus the drop across the diodes of the 372V bridge
For LiIon, select 84 cans. The voltage range will be:
84 * 2.85 = 239 ... 84 * 3.7 = 311 ... 84 * 4.2 = 353V
Pel = 1300/84 = 15.5W; Iel = 1000 * 15.5 /3.7 = 4200mah.
For LiFePO4, 96 cans are optimal. The voltage range will be:
96 * 2.8 = 268.8 ... 96 * 3.2 = 307.2 ... 96 * 3.65 = 350.4V
Pel = 1300/96 = 13.5W; Iel = 1000 * 13.5 /3.2 = 4232mah.
The cost of 96 LiFePO4 5500mah cells will be about 45000r. The cost of balancing devices for them is 5000 rubles. And addition: 50,000r. Weight 15kg.

Now let's make a calculation using a 115Vac drive, suitable, say, for an electric moped.
VACON0010-1L-0005 (4,3,2,1) -1-MACHINERY ~ 115V;
1.1 (0.75, 0.55, 0.37, 0.25) kW; 4.7 (3.7, 2.8, 2.4, 1.7) A
Input voltage Uin 115 V, -15%… + 10% 1 ~ 97.75… 126.5V
For a constant, this is: 138.24 ... 178.9V, minus the drop on the bridge 137 ... 177.5V
For LiIon, select 44 cans. The voltage range will be:
44 * 3.11 = 137 ... 44 * 3.7 = 163 ... 44 * 4.2 = 184.8V, conclusion: you can take about 90 ... 94% of the capacity.
For LiFePO4, 48 cans are optimal. The voltage range will be:
48 * 2.85 = 136.8 ... 48 * 3.2 = 153.6 ... 48 * 3.65 = 175.2V, conclusion: you can take about 98% of the capacity.

I'll take a 180W asynchronous motor (I have one), rewind it to 115Vac, "Slavyanka". 48 LiFePO4 5.5ah cells will cost 22.2 tons, plus balancing boards 2.5 tons. the mass of the battery will be 7.1kg. With a consumption of 180W on such a battery, you can go for 4.7 hours. At 500W - 1.7 hours.

In light of the fact that the inventor, Mr. Duyunov Dmitry Alexandrovich, revealed his secret of the combined winding of the Slavyanka type, I decided to draw up an approximate block diagram of a hybrid vehicle with such an engine.
I would like the forum participants to make their suggestions, comments, corrections.
In the calculations, I will proceed from the fact that the equipment will be installed on a car, for example VAZ 2109.
I'll start with the engine itself. A search on the Internet showed that a 4 kW motor can be used for rewinding, but a slightly more powerful motor such as 5kW should be used to achieve higher powers and speeds. After rewinding to "Slavyanka", the rated motor power should be more than 15kW, and the peak (during acceleration) 55 ... 65kW.
Initially, I assumed that it would be better to wind the engine at a lower voltage in order to reduce the number of battery cans, however, having familiarized myself with the range and prices for low-voltage frequency converters, I decided that it would be cheaper to use a standard industrial frequency converter, designed for power supply from a single-phase network ~ 220V or from 3 -x phase 200V.
An example of the first one can be "Aries" ПЧВ3-11К-Б - 11kW.
- the second VARISPEED CIMR-F7Z-2018 - 18kW.
However, what power the frequency converter should have is worth considering additionally, since at its peak it should produce up to 65kW.
It is supposed not to use a diode bridge at the input of the frequency converter, but to supply the supply voltage from the batteries directly to the filter capacitor. At the same time, the range of power supply from fully charged and completely discharged batteries is very large. For example, for a LiIon battery made up of 74 cans, the spread is 210.8 ... 307.2V. Therefore, it will be necessary to change the undervoltage protection circuitry inside the inverter so that it can operate with this variation. Perhaps the number of cans in the battery should be increased, for example, up to 83, then the voltage spread will be in the range 236 ... 348.6V, however, then you will have to make a non-standard generator, with alternating voltage the output is not ~ 220V, but ~ 250V.
If you use an inverter with vector control, then you can abandon the gearbox - gearbox.
Batteries can be used in different ways, each type has its own advantages and disadvantages. Lead-acid is the cheapest, but also the heaviest, but does not require balancing devices on each can. However, their most unpleasant drawback is the small number of charge-discharge cycles. That is why you shouldn't mess with them. As a result, it will turn out to be more expensive. Nickel - manganese, I don't know, you might think, but for some reason in industrial hybrids they are now being abandoned in favor of LiFePO4.
it a good option, the price for 1Ah is about 70 ... 80 rubles, balancing devices for 3.65V are required. Another plus of them is that during the discharge cycle, the voltage across them remains more or less stable within 3.3 ... 3V. Although, the operating range is considered to be 2.8 ... 3.65V. LiIon and LiPo have less weight with the same power, but their price is more than 100 rubles. For 1ah. Balancing devices are required on each 4.2V bank.
In general, it is advisable to use one of the latest types of batteries: LiIon or LiFePO4, the latter will have a lower price, more weight, and a slightly lower voltage spread.
It should be noted that a particularly large battery capacity is not needed. Their main function is a buffer between the generator and the frequency converter. During acceleration, energy is taken from the battery, while driving smoothly - from the generator, at the same time the battery is recharged for the next acceleration. The secondary function of the battery is to take energy into itself during engine braking.
A lot of different devices can be used as a generator. These are standard generators that run on gasoline, diesel oil or gas. The best results should be given by linear (vibration) generators, in which there is no crank mechanism, as a result of which, theoretically, their efficiency rises. You can use a Stirling external combustion engine combined with a linear generator and heat the hybrid with wood)))
I don't know what the power of the generator should be, I think you can try, start with 6kW.

Better, worse, it's not entirely appropriate here ...
Each type of engine has its own pros and cons.
One of the important advantages of a traction motor from a loader is the price and total cost of the motor + controller set and its high overload capacity, as mentioned above.
At this point, what is closer to you, more accessible, more interesting. Well, where and how are you going to operate the car.

This engine is used in rewound form. Its stator winding is replaced by a combined "Slavyanka" winding, with which the power it develops significantly increases and, in fact, is limited by the controller's power.