五相逆变器的空间矢量PWM控制

多相逆变器由于电压矢量的增加，其空间矢量PWM(SVPWM)控制同三相电机相比具有更大的灵活性，文中通过对五相逆变器电压矢量空间的分析，认为多相逆变器空间矢量PWM控制的线性调制范围及形成的电机定子磁通要优于三相电机。根据五相逆变器的结构特点，在传统的最近两矢量SVPWM(NTV-SVPWM)控制的基础上，提出了两种新的五相逆变器SVPWM控制方式：最近四矢量SVPWM(NFV-SVPWM)控制和最小开关损耗SVPWM(MSL-SVPWM)控制。推导了3种控制方式下的目标输出电压函数及波形，通过对比分析，认为：NTV-SVPWM控制含有较大的低次谐波，不适宜用于多相控制：NFV-SVPWM控制的输出谐波最小，MSL-SVPWM控制的开关损耗最小，分别适用于低调制指数和高调制指数工作区。利用MATLAB对五相同步电机调速控制系统进行了仿真研究，仿真结果验证了上述结论。

SPACE VECTOR PWM CONTOR OF FIVE-PHASE INVERTER

The space vector PWM (SVPWM) control of multi-phase inverter has more flexibility for the additional voltage vectors. According to vectors analyzing, the advantages of multi-phase inverter SVPWM control is presented in this paper. Two new SVPWM control methods for five-phase inverter are proposed comparing to the traditional Near Two Vectors SVPWM (NTV-SVPWM) control, and here they are called Near Four Vectors SVPWM (NFV-SVPWM) control and Minimum Switch Loss SVPWM (MSL-SVPWM) control. The target voltage functions and waveforms of three kind of SVPWM are deduced and compared. The conclusions can be drawn that there are much low frequency harmonics with NTV-SVPWM control, and which is not suitable for multi-phase inverter control; NFV-SVPWM has the best harmonics performance and is fit for low modulation index operation; MSL-SVPWM has the lowest switching loss and is fit for high modulation index operation. MATLAB is adopted to simulate the five-phase variable speed system, and the simulation results validate the conclusions above.