The protection functions can be divided into the following two categories:

(1) Corrective actions are automatically performed after detecting abnormal conditions, such as overcurrent stall prevention and regeneration overvoltage stall prevention.

(2) After the abnormality is detected, the PWM control signal of the power semiconductor device is blocked to make the motor stop automatically. Such as overcurrent cutoff, regeneration overvoltage cutoff, semiconductor cooling fan overheating and instantaneous power failure protection.