Analysis and Design of a High-Frequency Isolated Dual-Tank LCL Resonant AC-DC Converter

An integrated single-phase single-stage high-frequency (HF) isolated dual-tank LCL-type series resonant ac-dc converter with fixed frequency, phase-shift control strategy is presented. The circuit configuration combines a diode rectifier, boost converter and two identical halfbridge dc-dc LCL resonant converters. A high power factor (PF) and low total harmonic distortion (THD) is achieved by discontinuous current mode (DCM) operation of the front-end power factor correction (PFC) circuit. The output voltage is regulated by fixed-frequency, phase-shift between two identical half-bridge LCL resonant converters. Soft-switching operation is achieved for all the switches. The operation of intervals and steady-state analysis are presented briefly. Design example of a 100 W proposed converter is given together with its simulated and experimental results for different input voltages.