This paper proposes an optimal zero-current distortion compensation (ZDC) method for Vienna rectifier to improve dynamic characteristics at driving start-point. In the conventional ZDC method, the magnitude of output reference voltage is not considered. Therefore, at driving start-point where the modulation index of the output reference voltage is relatively large, the output reference voltage of a certain phase enters the overmodulation area by being added the ZDC components. It causes surge and distortion in the phase current. In this paper, the optimal ZDC (OPTM-ZDC) method is proposed, which re-derives the OPTM-ZDC component by considering whether overmodulation of output reference voltage occurs. When the output reference voltage of a specific phase exceeds the linear modulation area due to the ZDC component, the ZDC component applied to the other phases except for the phase in which the output voltage is in the uncontrollable region is modified. As a result, it is possible to reduce surge and distortion in the phase current due to overmodulation at driving start-point, even while maintaining the application of ZDC.
.jpg "Juyeon Lee, MS (she/her/hers) photo")