Improved Current Analytical Method for CLLLC Resonant Converter with Wide Voltage Range Operation
Accurate analysis of resonant current is an important part of calculating the loss of CLLLC resonant convert-er.Aiming at the small ratio of excitation inductance to resonant inductance of wide voltage gain CLLLC resonant con-verter,an improved resonant current analysis method was proposed based on current fitting approximation method.Firstly,we analyzed the equivalent topology of the converter during the ternary resonant period and wrote the phase ana-lytic expression of the resonant current.Secondly,considering the complexity of the calculation of the unknown trigono-metric function,we proposed the concept of the correction coefficient to simplify the calculation.Finally,we had the initial solution of the resonant current according to the waveform characteristics of the resonant current,and further ap-proximated the real value of the resonant current by the piecewise iterative method.The simulation results show that compared with the traditional method,the proposed improved current analytical formula can describe the variation process of resonant current more accurately during the ternary resonance period,which verifies the correctness of the proposed method.
CLLLC resonant converterresonant currentapproximate fitting of currentimproved analytical methoditerative computation
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维普
