A Modified Discontinuous Modulation Signal Based on 12-Sector SVPWM with Modulation Offset Injection for a Vienna Rectifier

The increasing demand for high-efficiency AC–DC conversion in modern power systems, such as Electric Vehicle (EV) charging, renewable energy integration, and industrial motor drives, has intensified research into advanced modulation techniques for Vienna rectifier. Conventional 6-sector Space Vector Pulse Width Modulation (SVPWM) strategies often suffer from limited modulation flexibility and insufficient performance at low modulation indices, where high DC-link voltage operation is required. To address these challenges, this paper proposes a modified discontinuous modulation signal based on a novel 12-sector SVPWM combined with a topology-aware switching scheme and modulation offset injection. A seven-segment switching sequence is designed for the proposed 12 sectors, enabling effective generation of Discontinuous PWM (DPWM) waveforms, improved current shaping, and Power Factor Correction (PFC). The simulation results indicate that the proposed method achieves a 9.24% reduction in Total Harmonic Distortion (THD) in the low-modulation region (ma<0.50) compared to the conventional method. Furthermore, dynamic tests confirm robust transient response under DC-link voltage steps, stable capacitor voltage balancing, and minimized switching commutation. These results demonstrate that the proposed modulation approach significantly enhances power quality, efficiency, and dynamic performance, making it a promising solution for next-generation high-performance Vienna rectifier systems.