On a hot summer day, an electric bus full of passengers, running at a crawling speed and unable to start the air conditioner, brought an extremely uncomfortable feeling to the passengers. The driver inadvertently communicated with the passengers about current electric vehicles , It triggered the author's thinking about the performance of automobile motors.

Compared with other motors, the particularity of automotive motor applications has resulted in higher performance requirements than other types of motors, such as specific requirements for vibration and noise control, efficiency and torque, etc. The key factors that determine the endurance index of electric vehicles include motors and batteries. As for the motor itself, a high-efficiency motor can better ensure the battery's duration, which is what we call power saving; and from the overall load analysis of the motor, relatively The lighter weight of the car body is naturally also an important component to ensure battery life. As an integral part of the car body, high power, high efficiency, and high power density naturally become the preferred requirements for motor performance.

For different models and vehicle conditions, the performance requirements for the motor are different. For example, for relatively stationary vehicles such as excavators, the weight index of the motor, that is, the power density index of the motor is not too high, while for models that tend to move, such as various For transportation and passenger cars, the power density requirements of the motor will be higher.

In order to achieve high efficiency and high power density of automobile motors, as well as to cope with the special requirements of different road conditions, permanent magnet synchronous motors based on flat wire windings are more capable, but the guarantee of motor performance and reliability is still a very serious issue. Question, statistics from an automobile insurance association found that the insurance acceptance rate of electric vehicles is much higher than that of ordinary gasoline vehicles. The quality improvement of electric vehicles is still urgent. As the main spare parts of electric vehicles, the efficiency and power of automobile motors The performance guarantee and improvement of density, winding temperature rise, vibration noise, torque, etc. are more urgent than ordinary motors. Design and development based on actual operating conditions will have more practical value.