Electric vehicle is the development trend of the automobile industry. We all know that the core of its principle is to replace the engine with motor to realize electric drive. Compared with conventional induction motor, electric vehicle motor has great differences in performance requirements and driving principle
1. Electric vehicle motor should have large starting torque, good starting performance and good acceleration performance to meet the requirements of frequent start stop, acceleration and deceleration or climbing. In the motor test, it is required that the response time of the motor should be short when the speed or torque control is carried out; at the same time, when the external load changes step by step, the motor itself should reflect fast enough to adjust the output power and speed;
2. The constant power range of electric vehicle motor should be designed to meet the torque output of electric vehicle at high speed and ensure the vehicle can achieve high speed;
3. The electric vehicle motor should have a wide range of speed regulation ability, with large torque at low speed and high power at high speed. It can adjust the driving speed and corresponding driving force at any time according to the driving needs;
4. The electric vehicle motor should have good efficiency characteristics, and obtain excellent efficiency in a wide range of speed / torque. Generally, 85% ~ 93% efficiency should be obtained in the typical driving cycle area for the continuous driving mileage after secondary charging;
5. The size of electric vehicle motor should be as small as possible, the weight should be as light as possible, and the power density should be optimized;
6. The electric vehicle motor should have good reliability, strong temperature and humidity resistance, long-term operation in harsh environment, low noise during operation and convenient maintenance;
7. Whether the motor controller can effectively recover the energy generated by braking.
Brush low-speed motor, no reducer gear device, simple structure, low cost, starting uphill overload capacity is poor, large power consumption. Because the speed of brush high-speed motor is high (high-speed motor is 3000 rpm, and low-speed motor is 500 rpm), it needs to output large torque power after deceleration by gear reducer, so its noise is relatively larger than that of low-speed motor. The production process of high-speed motor is more complex than that of low-speed motor, the cost is high, and the price is about 200 yuan.