Aiming at the current zero-crossing distortion in VIENNA rectifiers caused by the phase shift between the modulation voltage vector and the input current vector due to grid-side filters, this paper aims to propose a hybrid modulation strategy combining reactive current injection and zero-crossing clamping.
By calculating the minimum reactive current under given operating conditions, this strategy avoids over-modulation and dynamically adjusts the clamping interval to inject a compensation component within the optimized region, thereby suppressing input current distortion.
Experimental results demonstrate that under identical electrical parameters, the proposed strategy effectively improves current waveform quality, reducing the input current total harmonic distortion (THD) from 4.55% to 1.92%, which verifies the feasibility and effectiveness of the method.
The proposed strategy suppresses zero-crossing current distortion by coordinating minimum reactive-current injection and zero-crossing clamping. Compared with pure reactive-current compensation, the proposed method reduces the required reactive-current compensation by applying clamping in the optimized residual distortion interval. The method provides a carrier-based implementation with low computational complexity and is suitable for practical digital control.
