Research and simulation on minimized common-mode voltage based on SVPWM modulation algorithm

The high power domestic and commercial variable-frequency air conditioners powered by three-phase AC power supply have been widely used nowadays. In order to achieve much higher power factor at grid side, voltage source rectifiers (VSR) become popular. However, due to the high output voltage of VSR, the problem of common-mode voltage (CMV) on its DC link caused by traditional SPWM or SVPWM modulation algorithm is too serious to solve. Thus, the existing modulation algorithms of VSR should be modified to settle the problem of CMV. The paper designs a minimized CMV SVPWM modulation algorithm using non-zero vectors to replace the zero vectors, as well as a dead-time arrangement which causes no effect on CMV. Then the above theoretical analysis is verified via simulation by means of MATLAB/SIMULINK. The obtained results show that the minimized CMV SVPWM modulation algorithm can reduce the CMV, bringing about the alleviation of CMV interference.