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.
关键词
CLLLC谐振变换器/谐振电流/电流近似拟合法/改进型解析法/迭代计算
Key words
CLLLC resonant converter/resonant current/approximate fitting of current/improved analytical method/iterative computation
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