公开(公告)号：US09887647B2

公开(公告)日：2018-02-06

申请号：US14039984

申请日：2013-09-27

Applicant: SHENZHEN BYD AUTO R&D COMPANY LIMITED ,  BYD COMPANY LIMITED

Inventor： Hui Luo ,  Zhiyong Du ,  Xuguang Zhou ,  Xinxin Zhang ,  Xing Chen ,  Taotao Yang ,  Lipin Cheng

IPC: H02H7/08 ,  H02P21/00 ,  H02P6/00 ,  H02P6/12 ,  H02P6/34 ,  H02P29/024

CPC classification number: H02P6/12 ,  H02P6/34 ,  H02P29/0241

Abstract: A method for checking an out-of-step of a synchronous motor includes detecting three-phase currents of the synchronous motor; determining whether a relationship between the three-phase currents satisfies a preset requirement; and if no, determining that the synchronous motor is out of step. It is determined that the synchronous motor is out of step when amplitudes of each current of the three-phase currents are not equal or when the phase difference between the three-phase currents is not 120°.