SENSORLESS ROTOR ANGLE DETECTION CIRCUIT AND METHOD FOR A PERMANENT MAGNET SYNCHRONOUS MACHINE

摘要

An estimate of the initial position of a rotor is made by monitoring sensed motor current signals which are amplitude and phase modulated with the rotor flux position in response to a high frequency voltage signal injection. The motor current signals are envelope detected to determine zero crossing points. Samples are taken of the motor current signals at positive and negative offsets from the zero crossing point, with the samples processed to identify a direction of the rotor flux axis. Further samples of at least one motor current signal are taken with respect to a certain phase reference, and the samples compared to resolve a polarity of the rotor flux axis which is indicative of the angular position of the rotor.

主权项

1. A sensorless rotor angle detection circuit for a motor having multiple phase windings, comprising:
a drive circuit configured to inject a roto-pulsating high frequency flux into the motor; a sensor circuit configured to sense a high frequency motor current in response to the injected roto-pulsating high frequency flux; and a position detection circuit configured to process the sensed high frequency motor current to determine a rotor angle of said motor.