Why do motors with the same power have significant differences in size?

A netizen left a message: Why is the 200KW automobile motor so small and the 200KW industrial motor so huge? Can't industrial motors be replaced by automobile motors?

Aiming at the problem of the size difference between automobile motor and ordinary industrial motor with the same power, its substantive content is about the size and value of motor power density.

For motors with different applications, in addition to the necessary parameters such as power, rated voltage, torque, and speed, the matching relationship between the motor size and the space available for the accompanying equipment is particularly important, especially in cases where the space available for the motor is very limited. In such cases, there will be more constraints on the size and shape of the motor.

For most industrial motors, the supporting equipment for the volume of the motor is not particularly high, so the volume of the industrial motor is relatively large, therefore, the industrial motor for the electromagnetic wire, iron core materials and other conductor materials, the choice of freedom is larger, the product design process can also be adjusted through the motor volume, Optimize and meet motor temperature rise, efficiency and other performance indicators. In other words, due to the relative flexibility of the installation of industrial motors, the pursuit of power density of industrial motors is not very strict, and the direction of the output of the motor, the cooling method and other constraints affecting the volume and shape are relatively few.

For automotive motors, subject to the overall requirements of car body space and performance improvement, the capacity of the motor is subject to many limitations, so it can only be achieved by maximizing the power density of the motor to achieve the overall match with the car body. The power density of automotive motors is currently at the level of 3.5-4kW /kg, and with the popularization of new energy vehicles and the continuous improvement of motor technology, the index is expected to further increase. To this end, the automobile motor in the design and material is very sophisticated, such as in the selection of electromagnetic wire, winding type improvement, motor core material control, permanent magnet material selection and other aspects, relative to the ordinary industrial motor requirements are higher, especially for the higher endurance requirements of electric vehicles, the matching motor put forward higher satisfaction requirements.

Therefore, due to the different application characteristics of automotive motors and ordinary industrial motors, there will be a large difference in the volume requirements.