Method and System for Determining Motor Shaft Position

摘要

The present disclosure provides methods and systems for determining the rotor position of a BLDC motor having a saliency. Techniques according to the present disclosure advantageously may be used to determine a rotor position of a rotor which is not moving.

主权项

1. A method for determining a rotational position of a rotor of a brushless DC motor having at least a first phase and a second phase, the first phase and second phase being driven by a first pulse-width modulated (“PWM”) drive signal and a second PWM drive signal, the rotational position of the rotor being determined relative to a stator of the motor, the method comprising the steps of:
shifting a phase of the first PWM drive signal relative to a phase of the second PWM drive signal to produce a current ripple; obtaining a plurality of measurements, over a sampling period, of a current of the first phase of the motor and a current of the second phase of the motor; determining a current ripple based on the plurality of measurements; determining an inductance of the stator over time based on the current ripple and the first and second PWM drive signals; and determining the rotational position of the rotor based on the determined inductance.