反凸极永磁同步容错电机的短路特性分析

Short Circuit Characteristic Analysis of Negative-salient Permanent Magnet Synchronous Fault-tolerant Machine

反凸极永磁同步容错电机的直轴电感大于交轴电感,电机运行于基速及基速以下时,直轴电流为增磁性电流,其空载反电动势低。将反凸极与正凸极永磁同步电机的空载反电动势、电感特性、电流控制规律、恒功率调速范围、转矩密度、永磁体用量和过载能力等做对比分析,归纳出反凸极电机的特点;分别通过端部短路和匝间短路仿真及解析验证了反凸极电机有更强的短路电流抑制能力。具体而言,反凸极电机在绕组端部短路时,短路电流相比正凸极更小。在分析反凸极电机绕组匝间短路时,采用等效磁路法对电感参数进行解析,得出短路电流的变化规律,结果显示,反凸极永磁同步容错电机的空载反电动势低,因此在不牺牲过载能力情况下可以有效抑制短路电流。

As Ld of negative-salient permanent magnet synchronous fault-tolerant machines is greater than Lq.D-axis current strengthens the permanent magnetic field at rated speed or lower than the rated speed.So it’s no-load back EMF is lower.Firstly,we analyzed and compared negative-salient and positive-salient permanent magnet synchronous machine(NSPMSM and PSPMSM)of the no-load back EMF,inductance characteristics,current control technology,constant-power speed rang,torque density,permanent magnet usage and overload capacity.Basing on these research,we summarized the characteristics of NSPMSM.Then,by the simulation and analyzing of the winding terminal short-circuit(SC)and the interturn SC respectively,it is verified that the NSPMSM has stronger SC current suppression capability.Specifically,as NSPMSM winding terminal is short-circuited,the SC current is smaller than PSPMSM.As we analyzed winding interturn SC of the NSPMSM,we calculated the inductance parameters of interturn SC by equivalent magnetic circuit method and obtained the rule of SC current varying with the number of SC turns.Results show that the no-load back EMF of NSPMSM is lower.Thus,it can suppress SC current in the case of maintaining the overload capability.