Phase-Controlled Three-Phase Rectifiers Without Grid Synchronization: A New Approach

Three-phase rectifiers play a vital role in industry, often requiring grid synchronization for proper operation. However, existing synchronization methods typically rely on AC voltage sensors, besides being complex systems. This paper introduces a novel approach to controlling phase-controlled three-phase rectifiers without the need for grid synchronization, and notably, without digital controllers, based only on simple average voltage measurement and a feedback control, thus enabling assembly using only analog hardware. The operational principle is explained, accompanied by a mathematical analysis demonstrating asymptotic stability under specified conditions. Comparative simulations against a conventional synchronization method, the Synchronous Reference Frame Phase-Locked Loop (SRF-PLL), indicate comparable, if not superior performance, with notably improved average settling times. These results suggest that the proposed system could effectively replace SRF-PLL in suitable applications. Nonetheless, further research is warranted to enhance system performance and increase reliability.