A High-Frequency Link Three-Phase Dual-Inverter System Using Two Phase-Shifted Single-Phase Series Resonant Inverters

Abstract

A novel inverter system to synthesize three-phase sinusoidal currents with a combination of two units using two phase-shifted single-phase series resonant inverters is proposed. The structure and operating principle of the proposed system are described and its features are compared with conventional inverters. Each unit consists of a high-frequency single-phase reasonant inverter, a single-phase transformer for electrical isolation, a rectifier, a low-pass filter, and a three-phase inverter to unfold the DC link current. The system has advantages of both a high-frequency resonant inverter and a high-frequency AC link. The simulated and experimental results show that the system can produce high quality output current waveforms. Effects of the cutoff frequency of the low-pass filter in the DC link on the output waveforms are, also, discussed.