Method of detection null of installation angular difference of rotor magnetic standard of synchronous motor and standard position of position

摘要

PURPOSE:To decide the reference position of the rotor of a motor by fixing the conducting pattern given to the stator of the motor while only the conducting value of the pattern is left variable and driving a power converting section under two conducting conditions, and then, finding the angle difference between the rotor and an encoder from the detected position and conducting value when the motor reaches a stable position at each conducting value. CONSTITUTION:A PWM power converting section 3 is driven by only changing the conducting value of the conducting pattern given to the stator of a three- phase synchronous motor 1 against a current command given to a three-phase distributor 5. When the motor 1 reaches a stable position with the conducting value, the position detecting signal of an encoder 9 and the conducting value are stored. When the measurement is executed by a prescribed number of times, the reference position of the rotor of the motor 1 is found by calculation from the calculating formula of the method of least squares, etc., by using the stored values.