一种补偿谐波电流的无刷双馈电机转矩脉动抑制方法

Torque ripple suppression method for brushless doubly-fed machine with harmonic current compensation

针对无刷双馈电机存在较强转矩脉动的问题,根据旋转坐标系下电流与转矩之间的关系,明确了功率绕组电流中含有的谐波分量会导致电机运行时产生转矩脉动的结论,提出以谐波补偿电流的方式抵消电机运行时产生的谐波分量来抑制无刷双馈电动机转矩脉动,采取了功率绕组谐波电流瞬时检测方法与空间矢量滞环控制方法来满足系统对实时性和准确性的要求。该转矩脉动抑制方法能有效提高无刷双馈电机的机械特性和调速性能,对于降低无刷双馈电机绕组谐波含量提高整机效率提供了参考。最后以一台45 kW的绕线转子无刷双馈电机为例进行了验证,通过对谐波电流补偿法在电机异步、同步以及超同步运行状态下的仿真对比分析,结果表明该方法可有效抑制电机的谐波转矩脉动,提高电机运行性能。

The harmonic component contained in the power winding current will lead to torque ripple when the motor is running.Aiming at the problem of strong torque ripple in brushless doubly fed motor,according to the relationship between current and torque in rotating coordinate system,it is proposed to suppress the torque ripple of brushless doubly fed motor by offsetting the harmonic component generated by the motor in the way of harmonic compensation current.The instantaneous detection method of harmonic current of power winding and space vector hysteresis control method were adopted to meet the requirements of real-time and accuracy of the system.This torque ripple suppression method effectively improved the mechanical characteristics and speed regulation performance of brushless doubly fed machine,and provided a reference for reducing the harmonic content of brushless doubly fed machine windings and improving the efficiency of the whole machine.Finally,a 45 kW wound rotor brushless doubly fed machine was taken as an example to verify the method.Through the simulation and comparative analysis of the harmonic current compensation method in the asynchronous,synchronous and super synchronous operation state of the motor,the results show that the method can effectively suppress the harmonic torque ripple of the motor and improve the operation performance of the motor.