Abstract

This paper proposes a symmetrical sine-carrier pulse width modulation (SSCPWM)-based space vector modulation (SVM) strategy for enhancing the performance of a three-phase two-level Wye rectifier. Unlike conventional triangular-carrier PWM (TCPWM) and inverted sine-carrier PWM (ISCPWM), the proposed method employs a symmetrical sinusoidal carrier waveform to reshape the pulse distribution while preserving the simplicity of comparator-based carrier PWM implementation. The modulation signals are generated from a current-sector-based SVM framework. These signals are then directly compared with the proposed carrier to generate the switching signals. Analytical expressions for the switching instants and duty ratios are derived to clarify the nonlinear carrier-crossing characteristics introduced by the sinusoidal carrier. The proposed method was evaluated under both open-loop and voltage-oriented control (VOC) operations using detailed MATLAB/Simulink simulations. The results demonstrated that the proposed SSCPWM achieved improved harmonic performance relative to TCPWM and ISCPWM schemes. The proposed method also reduced the DC-link voltage ripple. Comparable switching-loss characteristics were still preserved. Under VOC operation, the proposed method achieved a phase-current THD of 3.21%. This value corresponded to 16.0% and 16.8% reductions compared with TCPWM and ISCPWM, respectively. The DC-link voltage regulation performance remained comparable to that of the conventional methods. The proposed strategy exhibits improved transient current quality during load variations without increasing the switching frequency or modifying the conventional VOC structure. The results indicated that the proposed SSCPWM can provide a practically feasible solution for improving the power quality of a grid-connected two-level Wye rectifier.