Advanced Modulation Control for Three-Phase Single-Stage DC-AC Conversion with Optimized Filter Reduction

The present article introduces a single-stage threephase DC/AC converter that incorporates an optimized filter design, aiming to simplify the power conversion process. Conventionally, to generate three-phase pure sinusoidal waveforms, three-power conversion stages are involved: a DC-DC converter, DC-AC inverter and a filter circuit. The term “single-stage” highlights the integration of these functionalities into a single conversion stage, which significantly reduces the system's complexity and size. Compared to the state-of-art approaches, the converter operates with a quantized sinusoidal modulation technique (QSMT). With an inherent filtering property, the QSMT is able to generate sinusoidal output waveforms, thus reducing the additional filter requirements. The operation of three-phase converter topology along with the suggested control scheme is thoroughly examined mathematically. Further, a brief discussion on the parametric design of passive components is presented with the investigation of filter size reduction compared to other modulation strategies. A comparative analysis with existing literature demonstrates the advantages of the proposed QSMT in terms of filter type, size, device count and harmonic distortion. The provided simulation results illustrate the operations of the converter topology using the control scheme.