S/SP非接触谐振变换器的时域特性分析

Time-domain Analysis of S/SP Compensated Contactless Resonant Converters

S/SP非接触谐振变换器因为对系统参数变化尤其是变压器的耦合系数变化不太敏感,具有良好的应用前景。但该变换器中主要波形谐波含量较大,导致基波分析方法误差较大,直接影响到变换器的参数设计以及控制的有效性。为此论文对变换器的时域特性展开研究。论文考虑谐波影响,推导谐振网络的通用等效电路,揭示谐波产生的原因,建立谐振腔各波形的定量表达式。在时域波形分析的基础上,论文进一步研究变换器的输出增益特性,推导精确的电压增益并指出基波分析方法结果偏大的原因。最后,设计一台1.5 k W的S/SP非接触谐振变换器,特征波形、电压增益的实验与分析结果吻合良好,验证了论文所采用的时域特性分析方法的正确性。

The series/series-parallel（S/SP） compensated contactless resonant converter has a desirable feature of being insensitive to variation of parameters including the transformer＇s coupling coefficient. However, the error resulting from the use of fundamental harmonic approximation is significant, which affects the design procedure and the effectiveness of the control. In this paper, a time-domain analysis of the S/SP converter was presented. A generalized equivalent circuit of the S/SP resonant tank was derived, and the cause of the waveform distortion was revealed. Then, more accurate expressions for the key variables of the resonant tank and the output voltage gain were given. Finally, a 1.5 k W contactless resonant converter with S/SP compensation was constructed. Experimental results are in good agreement with the calculated results.