Variable Resonant and Switching Frequency Charging Control Strategy of LCC Converter with Wide Range Load

A function between output current of LCC resonant converter with capacitive load and normalized switching frequency is established using Fundamental Harmonic Approximation (FHA). A two-stage charging control strategy is proposed using a switch to change the resonant frequency to reduce the switching frequency range in constant charging (CC) mode with wide range load. The accuracy of the proposed technology is verified through a 800V, 1A LCC converter model built in SIMULINK of MATLAB. A prototype is manufactured which verifies that the two-stage charging control can reduce the switching frequency range by 50kHz