电励磁双凸极电机起动全过程励磁控制策略

电励磁双凸极电机由于励磁电流可控制,用于起动工作时理论上能够调节励磁电流实现恒功率控制。但是由于双凸极电机的非线性特性导致其反电势为不规则方波形状,类似直流电机采用相电压反馈控制励磁电流实现恒功率控制困难较大。本文在双凸极电机恒转矩起动阶段,恒流控制励磁电流,根据起动机转速反馈实现控制模式的平稳切换;在恒功率阶段利用三相端电压整流值间接测量反电势来控制励磁电流,实现双凸极电机弱磁控制,保证恒功率阶段电机的出力最大。仿真和实验结果验证了该方法的有效性。

Flux Control for Start Process of Doubly Salient Electrical Motor

In the process of starting, the electro motive force(EMF) of doubly salient electrical motor (DSEM) can be maintained for the constant power control by the flux weakening in theory as the flexible flux. However, the nonlinear magnetic characteristics of DSEM cause EMF to be anomalous square wave. It is difficult to control the excitation current by the close loop of EMF as DC motor. In this paper, the excitation current of DSEM is constantly controlled in the process of constant torque. The flux weakening control method with the feed back of the rectified voltage for three terminal phases is given. The switch process from the state of constant torque to constant power is smooth and the maxim output of DSEM is maintained in the process of constant power. Simulation and experimental results confirm the theory of the flux weakening method.