Design of the parallel resonant converter as a low harmonic rectifier

A 1.4 kW single-phase high-efficiency AC-DC converter which draws sinusoidal and in-phase current has been designed, constructed, and experimentally tested. The converter is based on the parallel resonant converter (PRC) with active control of the input line current. It operates in the frequency range from 44 kHz to 71 kHz below resonance, and features zero current switching (ZCS) of insulated gate bipolar transistors (IGBTs). The converter steady-state input characteristics and component stresses are derived in closed form and in a new manner, which allows easy determination of how applied voltages, currents, and stresses on components vary with instantaneous input line voltage and load. Relevant transfer functions and equivalent circuit models in the presence of an input filter are also derived. The input filter is damped and the input current feedback loop is closed to actively regulate the input current waveshape. The results are verified by computer simulation and laboratory experiment.<>