The choice of the rated motor power of the reducer is a very important and complex issue.When the load is too high, if the rated power of the motor is too large, the motor will often be in a light-load operation state, the capacity of the motor itself will not be fully utilized, and it will become a "big horse" car, and the motor operation efficiency is low. Poor performance will increase. Operating expenses. On the contrary, the rated power of the motor is very small, that is, "small horse-drawn carriage", the motor current exceeds the rated current, the motor loss increases, the efficiency is low, and the most important thing is to affect the service life of the motor, Even if there is not much overload, the service life of the motor will be reduced even more; the overload will destroy the insulation performance of the motor insulation material or even burn out. Of course, the rated power of the motor is very small, and the load may not be dragged at all, which may cause the motor to be long The time is in the starting state and is damaged due to overheating. Therefore, the rated power of the motor should be selected strictly according to the operation of the electric vehicle.