Patent ID: 9184683
Filing Date: 2015-11-10
Classification: H02P

Abstract:
1. An applied-voltage electrical angle setting method for a synchronous motor, the method comprising: detecting an applied voltage applied to a stator coil of the synchronous motor, and a current flowing through the stator coil according to the applied voltage; calculating a present applied voltage phase (or an applied voltage electrical angle) and calculating a current peak value based on the detected applied voltage and current, and calculating a target current phase based on the current peak value followed by calculating a target applied voltage phase (or a target applied voltage electrical angle) corresponding to the target current phase; and calculating a new applied voltage electrical angle instruction value, based on a change angle obtained by correcting a difference between the present applied voltage phase (or the applied voltage electrical angle) and the target applied voltage phase (or the target applied voltage electrical angle) by a response time constant of the synchronous motor, a rotational speed calculated based on the detected applied voltage and current, and the previous applied voltage electrical angle instruction value.