基于空间矢量调制的电励磁磁通切换电机转矩角增量控制策略

电励磁磁通切换电机具有转子结构简单坚固,磁链双极性、反电势正弦度高的优点,是一种新型的无刷交流电机。交流电机的2种经典控制策略中,相对于矢量控制(vectorcontrol,VC),直接转矩控制(direct torque control,DTC)具有算法结构简单、动态性能好的优点,但是其电流谐波含量高、转矩和磁链脉动大。为同时提高调速系统的动、静态性能,该文研究了一种基于空间矢量调制(space vectormodulation,SVM)的电励磁磁通切换电机转矩角增量控制策略,定义转矩PI环的输出为转矩角变化量,通过合成空间矢量对定子磁链矢量角增量的直接平滑调节,实现了对电磁转矩的直接线性调节。比较了最大合成空间矢量和基本前进矢量改变定子磁链矢量角的能力。在一台电励磁磁通切换电机上,利用TMS320F2812控制系统进行了传统DTC和该文提出算法的比较实验,验证了所提算法的正确性和有效性,新算法具有优良的动、静态性能。

A Torque Angel Increment Control Strategy for Electrical Excitation Flux-switching Machines Based on Space Vector Modulation

The electrical excitation flux-switching(EEFS) machine,having rugged rotor,bipolar flux linkage and sinusoidal back-EMF,is a new type of brushless ac machine.The direct torque control(DTC),which is one of the two basic control strategies(vector control and direct torque control) of ac machine,has simple structure and good dynamic performance but has high current total harmonic distortion(THD) and big ripple in torque and flux.Thus in this paper,in order to improve both steady and dynamic performances of the EEFS machine control system,an optimized torque control strategy based on space vector modulation(SVM) was proposed,in which the output of PI-based torque controller was defined as the increment of torque angel,and electromagnet torque could be linearly regulated by directly and smoothly controlling stator flux linkage vector increment using space vectors.Further,the capabilities of change stator flux linkage vector increment of maximum space vector and basic forward vector were compared.Comparative experiments of traditional DTC and the proposed strategy were carried on an EEFS machine based on TMS320F2812 control system.The results verify the effectiveness and good dynamic and steady performance of proposed strategy.