New Three-Phase LLC Resonant Converter

To address the challenge of low output voltage in photovoltaic (PV) systems, which often does not match the bus voltage, a novel three-phase Y-Y LLC resonant converter is proposed. This converter consists of a three-phase inverter network, a three-phase resonant tank, and a newly designed threephase voltage-doubling rectifier network. It achieves twice the voltage gain of conventional three-phase Y-Y LLC resonant converter, with voltage stress on rectifier-side components reduced to half of the output voltage. Additional advantages include low input current ripple, low output voltage ripple, selfbalancing output capacitor voltages on the rectifier side, and electrical isolation. The paper provides a detailed analysis of the converter's operating principles and core characteristics, supported by simulations to validate its feasibility and effectiveness.