Abstract:
Aiming at the circulating voltage of parallel high-frequency resonant inverter caused by parameter difference, a modulation strategy is proposed to realize the decoupling and independent regulation of the output voltage phase and amplitude. By adopting the proposed modulation strategy, the circulating voltage between the parallel inverter can be effectively suppressed. Firstly, the characteristics of resonant inverter are analyzed, the fundamental wave circuit model is established based on the fundamental wave analysis method, and the equivalent impedance model of parallel inverter is derived by combining KVL equation. After that, the mathematical model of circulating voltage is defined, and the factors influencing circulating voltage are analyzed and compared. Then, the decoupling characteristics of proposed modulation strategy and the double closed-loop voltage sharing strategy are analyzed. Finally, the simulation and experimental platform with an operating frequency of 25 kHz and an output power of 250 W is built. The simulation and experimental results verify the feasibility and effectiveness of the proposed modulation strategy.