基于电流矢量角的IPMSM最大转矩电压比深度弱磁控制

Deep Flux Weakening Operation of IPMSM by Using Maximum Torque per VoltageControl Based on Current Vector Angle

电机处于高速轻载工况下,为了使电机效率最佳,需要控制电机电流工作点从最大转矩电压比(MTPV)轨迹沿着电压极限椭圆切换至普通弱磁区。基于直轴电流差的MTPV控制算法能够实现该电流轨迹控制,但是切换过程不平滑,伴随着电流和转矩震荡。在超前角弱磁法的基础上,提出一种基于电流矢量角的MTPV控制算法,利用电流矢量角查表得到MTPV轨迹上的电流矢量幅值,以此作为约束条件来实现MTPV控制,由于未使用开关来完成电流轨迹切换,MTPV轨迹至普通弱磁区实现平滑切换,电流和转矩平滑过渡。Matlab/Simulink仿真验证了所提算法的有效性。

The current operating point is switched from the maximum torque per voltage(MTPV)trajectory to the normal flux weakening region along the voltage limit ellipse in order to optimize the motor efficiency,under the conditions of high speed and light load for motor.That current trajectory control can be realized by the MTPV control algorithm based on direct-axis current difference,but the switching process is not smooth,accompanied by current and torque oscillation.An MTPV control algorithm based on current vector angle was proposed via modification of the leading angle flux weakening method.In the proposed algorithm,the current vector amplitude of the MTPV trajectory was obtained by using current vector angle to lookup table,which was used as a constraint to realize MTPV control.And there was no switch to complete the current track switching,so the switching process from MTPV track to ordinary flux weakening region was smooth,the transition of current and torque was also smooth.The effectiveness of the proposed algorithm was verified by Matlab/Simulink.