标题：Demagnetization Study of Line-start Permanent Magnet Synchronous Motor Under Out-of-step and Supersynchronous Faults
作者：Tang, Xu; Wang, Xiuhe; Li, Guanqun; Tian, Mengmeng
作者机构：[Tang, Xu; Wang, Xiuhe; Li, Guanqun; Tian, Mengmeng] Shandong Univ, Sch Elect Engn, Jinan, Peoples R China.
会议名称：IEEE 11th Conference on Industrial Electronics and Applications (ICIEA)
会议日期：JUN 05-07, 2016
来源：PROCEEDINGS OF THE 2016 IEEE 11TH CONFERENCE ON INDUSTRIAL ELECTRONICS AND APPLICATIONS (ICIEA)
关键词：line-start permanent magnet synchronous motor; out-of-step fault;; supersynchronous fault; demagnetization
摘要：When the line-start permanent magnet synchronous motor (LSPMSM) operates stably, sudden change of load torque may result in out-of-step and supersynchronous faults. The currents in stator windings and rotor bars will increase under the two faults, so will the strength of demagnetization field, which is likely to cause the irreversible demagnetization of permanent magnets in LSPMSM. This paper adopts two-dimensional finite-element method (2-D FEM) to analyze the demagnetization characteristics of LSPMSM under out-of-step and supersynchronous faults. The operating points of all positions in permanent magnets are not exactly the same, and the variation of magnets' minimum operating point, which is the minimum value of operating points of all positions in permanent magnets, is used to reflect the variation of demagnetization field strength. The influences of initial load condition, load torque change time as well as the load torque after change are studied, and corresponding conclusions are drawn.