When buying traditional fuel vehicles, people often pay the most attention to the "three major parts" of the car, of which the engine is called the "heart" of the car, which is also the part that everyone cares about most.
"Self-priming engines are good, or turbocharged engines are good", this was a topic that was often discussed. Talking about the color change of the three-cylinder engine also proves that consumers will really give up a car because of the engine.
However, with the blowout rise of new energy electric vehicles, electric vehicles also have "three major parts" of batteries, electronic controls and motors, but consumers' attention to the "engine of electric vehicles" - motors is almost zero. No one chooses or does not choose a model because of the quality of the motor.
Today's car consumers, why do not pay attention to the "three major pieces" in electric vehicles?
Buying a car is a prudent process, and everyone wants to know something about the car they want. However, we are extremely unfamiliar with the criteria for judging motors, and we do not understand what is good or bad. Even some models of motors can not be seen or touched, and it is more difficult to identify the level of hardware. Therefore, it may be necessary to know more about the motors of electric vehicles.
Today, Pin Play/Pin Drive will come to talk to you about the electric vehicle motor.
What are the types of electric vehicle motors?
In fact, the earliest use of electric vehicles is a DC motor, when the DC motor is relatively mature. The control method is simple and the speed regulation is fast, so the DC motor is used in the early electric vehicles.
However, almost no manufacturers use DC motors anymore. The reason is that the DC motor structure is complex, and it restricts the instantaneous load capacity and speed capacity, which not only wastes energy, heat dissipation difficulties, but also produces electromagnetic interference, which is not good for the mileage of electric vehicles and safe driving. In addition, the DC motor can not achieve the braking kinetic energy recovery function, so it gradually withdrew from the automotive stage.
At present, there are two types of motors most commonly used in electric vehicles: "permanent magnet synchronous motors" and "AC asynchronous motors".
Permanent magnet synchronous motors are the most widely used
Check the configuration table of mainstream electric vehicles on the market, Tesla Model 3, Mercedes-Benz EQS, Polar Fox Alpha S, BYD Han EV, WM W6, Weilai EC6, Xiaopeng P7, etc., two-wheel drive models almost all use permanent magnet synchronous motors. Four-wheel drive dual-motor models also mostly use a combination of "front permanent magnet synchronous motor" + "rear AC asynchronous motor".
Why has permanent magnet synchronous motors become the first choice in the industry?
The rotor of the permanent magnet synchronous motor is a permanent magnet, and the speed of the rotor is always consistent with the current frequency of the stator windings. Since there is no need to install brushes and mechanical steering structures, there is no spark when working, so it is safer and more reliable to operate.
Compared to other motors at the same power, permanent magnet synchronous motors are smaller in size and weight. More importantly, it has a high power density and torque density, which can meet the performance needs of most electric vehicles.
Permanent magnet synchronous motors are good at running between 4000rpm-10000rpm, and at the same mass and volume, it can provide greater power output and acceleration for new energy vehicles. To put it bluntly, this kind of product price ratio and comprehensive capabilities are better, which is why car companies prefer permanent magnet synchronous motors.
Of course, everything is not absolutely good, and the permanent magnet synchronous motor also has its weaknesses. The price of permanent magnet materials is higher, which makes the cost of permanent magnet synchronous motors higher. Secondly, the permanent magnet material on the rotor will produce magnetic decay under the conditions of high temperature, vibration and overcurrent, and there is a certain risk of motor damage.
AC asynchronous motors are "complementary"
It is not difficult to find from the car configuration table that many four-wheel drive dual-motor models use the combination of front permanent magnet synchronous motor and rear AC asynchronous motor.
Why is AC asynchronous motor used in four-wheel drive models?
First of all, AC asynchronous motors are less expensive than permanent magnet synchronous motors, have a simple structure, and are reliable and durable. The use of such a combination in four-wheel drive models is certainly cheaper than the front and rear dual permanent magnet synchronous motors.
Secondly, the AC asynchronous motor can withstand a large number of working temperature changes, the working number of revolutions is wide, the peak number of revolutions can reach about 20000rpm, even if it does not match the secondary differential can also meet the high-speed cruise speed requirements of the vehicle. This is conducive to the acceleration performance of electric vehicles as well as the performance of high-speed driving.
However, the disadvantages of AC asynchronous motors are low power density, volume and weight are larger than permanent magnet synchronous motors. This is certainly not the first choice for electric vehicles with high requirements for weight and efficiency, and it is the most common way on the market to use it with permanent magnet synchronous motors.
Does the type of motor determine the performance of the vehicle?
For auto consumers, even if you know that your car uses a permanent magnet synchronous motor or an AC asynchronous motor, you don't know why the same type of motor will accelerate faster or perform better than yours.
In addition to the type, the motor also depends on indicators such as efficiency and NVH. High efficiency can lead to higher mileage, and good NVH can bring better comfort to electric vehicles.
Motor efficiency can generally be tested by the bench, and the ratio of output mechanical energy to input electrical energy is the efficiency of the motor. Of course, the motor efficiency performance can be shown by MAP diagram, which is more intuitive and clear.
However, when you buy an electric car, how the motor performs, the continuous power of the motor, the peak power and the continuous torque, peak torque and other information are basically ignored. Most of us only focused on the issues of range and intelligent driving assistance level.
However, in addition to the performance of the motor, the quality of the motor and the performance of the good or bad, but also affected by the manufacturer, the performance and quality of the motor out of the big factory are basically better. At present, the more well-known motors on the market are BorgWarner, Bosch, Jingjin Motor, Dayang Motor and so on.
However, how many consumers who buy an electric car know what brand of motor their car is? This has to reflect a little on why the "engine" of electric vehicles has been forgotten by consumers.
Write at the end:
From the perspective of the types of motors used by major manufacturers, permanent magnet synchronous motors and AC asynchronous motors are undoubtedly the most mainstream choices. There may also be people who will mention "switched reluctance motor", but noise and vibration problems also lead to the type of motor that automakers prefer, and we will not discuss it too much.
In today's rise of new energy electric vehicles, we buy electric vehicles and do not care as much about hardware as when buying traditional fuel vehicles, and even know nothing about important components such as motors, but are attracted by intelligent driving, intelligent cockpits and other icing on the cake. This is obviously contrary to the thinking of the past when we bought a car.
Looking at the quality of an electric car is not just how many kilometers it can run and how many radar cameras it can. We need to look at electric vehicles more comprehensively, and even what kind of steel is used is worthy of consumer attention. After reading this article, I hope that you will also pay more comprehensive attention to electric vehicles, and do not let the manufacturer's emphasis on publicity obscure your eyes.