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1. (WO2018176720) METHOD AND SYSTEM FOR CORRECTING ZERO POINT OF ROTARY TRANSFORMER OF PERMANENT MAGNET SYNCHRONOUS MOTOR

Pub. No.:    WO/2018/176720    International Application No.:    PCT/CN2017/097374
Publication Date: Fri Oct 05 01:59:59 CEST 2018 International Filing Date: Tue Aug 15 01:59:59 CEST 2017
IPC: H02P 6/18
Applicants: SUZHOU INOSA UNITED POWER SYSTEM CO., LTD
苏州汇川联合动力系统有限公司
Inventors: JIANG, Jianjun
蒋建军
Title: METHOD AND SYSTEM FOR CORRECTING ZERO POINT OF ROTARY TRANSFORMER OF PERMANENT MAGNET SYNCHRONOUS MOTOR
Abstract:
A method and system for correcting a zero point of a rotary transformer of a permanent magnet synchronous motor. The method comprises: S100. sampling a counter-electromotive force and a rotary transformer signal of a line voltage of a motor under a free rotation state, and comparing the time difference between the counter-electromotive force and the rotary transformer signal at the same position; S200, calculating the zero point offset of a rotary transformer according to the motor frequency and the time difference; and S300, compensating, on the basis of the zero point offset, a position signal fed back by the rotary transformer so as to correct the zero point of the rotary transformer. Implementation of the method and system for correcting the zero point of the rotary transformer of the permanent magnet synchronous motor has the following beneficial effects: a zero point is captured using a counter-electromotive force of a line voltage of a motor, and the zero point offset is related to the motor frequency; therefore, the precision is high, and the method and the system can be suitable for motors of different types and different models; the sampling and calculation process is simple, the delay is low, and the precision of the zero point offset obtained by calculation is higher.