宽范围双向LLC变换器轻载低增益下移相控制的分析与应用

Analysis and Application of Phase Shift Control for Wide Range Bidirectional LLC Converter under Light Load and Low Gain

开关器件工作频率越高对开关器件的要求越大。为了在工作频率不变的条件下扩大双向LLC反向工作时的输入和输出电压范围,提出了LLC定频移相的控制策略,并采用FHA方法分析电路。对移相控制时的增益进行理论分析,由器件效率的影响界定工作频率点及最大移相角度,最后基于样机验证了试验结果,得到实际的效率曲线与工作波形。

The higher the working frequency of the switch device, the higher the requirement of the switch device.In order to expand the input and output voltage range of two-way LLC reverse working under the condition of the same operating frequency, a control strategy of LLC fixed frequency and phase shift is proposed, and the FHA method is used to analyze the circuit.The gain of phase shift control is analyzed theoretically.The operating frequency point and maximum phase shift angle are defined by the influence of device efficiency.Finally, the experimental results are verified based on the prototype, and the actual efficiency curve and working waveform are obtained.