Common-mode voltage supression of dual Y shift 30° six-phase electric machine

There are two common-mode voltages (CMVs) in a system composed of dual Y shift 30° six-phase electric machine and power converter, which bring detrimental effects on the system. To suppress the amplitude and changing frequency of CMV, a method with six-phase space vector pulse width modulation (SVPWM) is presented. The six intermediate vectors which become zero vectors in o1-o2 and z1-z2 planes are structured by twelve non-zero basic vectors with linear combination method. The two CMVs of each of these twelve basic vectors are equal. The expected vector in d-q plane can be synthesized by intermediate vectors. Experimental results show that the peak-to-peak value of CMV is 1/3 of DC-bus voltage of converter, the changing frequency of CMV is much less than the switching frequency of converter.