Modified Gating Signal Controlled High-Frequency Transformer Isolated LCL-T Type DC-DC Resonant Power Converter

In this paper, a LCL-T type of resonant power converter using modified gating signals is proposed for PV applications. The fixed-frequency modified gating is adopted to process and control the power flow in the circuit. The converter is designed to operate in lagging pf mode to ensure zero-voltage switching (ZVS) of the inverter switches. Fourier series method is used to analyze the converter in steady-state. The main advantage of LCL-T converter is that it provides protection against load short circuit. It is shown that a small change in pulse width is required to regulate the output voltage for variations in input voltage and load. A 300 W converter is designed and its performance is studied using PSIM simulations. Power loss breakdown analysis is performed.