BRUSHLESS AND SENSORLESS DC MOTOR CONTROL SYSTEM WITH LOCKEDAND STOPPED ROTOR DETECTION

摘要

A motor control system (20) for a brushless and sensorless DC motor (22) for driving a compressor (28), pump or other application, includes a protection and fault detection circuit (42) for detecting a locked rotor (26) and a rot or which has stopped because of lost rotor phase lock. The motor control system also includes an off-the~shelf motor control integrated circuit (40) having an input for disabling power outputs to the motor phase coils. The protection a nd fault detection circuit uses a back EMF sampling circuit (54) coupled to the motor phase coils (24a-24c) and momentarily disables power to the motor phas e coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.