单极性移相控制电压源高频交流环节AC/AC变换器研究

该文首次提出并深入研究了基于正激Forward变换器的单极性移相控制电压源高频交流环节AC／AC变换器。这类变换器由输入周波变换器、高频变压器、输出周波变换器、以及输入、输出滤波器构成。输入周波变换器将输入不稳定劣质的交流电压调制成双极性三态的高频交流电压，输出周波变换器将此高频交流电压解调成单极性三态SPWM波，经输出滤波后得到稳定优质的正弦交流电压。通过输入周波变换器右桥臂相对左桥臂的移相，让输出周波变换器功率开关在输入周波变换器输出的高频交流电压为零期间进行换流，并借助输出周波变换器换流重叠和输入电压极性选择，从而实现了变压器漏感能量和输出滤波电感电流的自然换流、输出周波变换器的ZVS开关。详细分析了这类变换器在1个高频开关周期内的12个工作模式及其等效电路，获得了变换器外特性曲线与关键电路参数设计准则。原理试验结果证实了这类变换器新概念，为实现新型电子变压器、正弦交流稳压器和交流调压器奠定了基础。

RESEARCH ON THE UNI-POLARITY PHASE-SHIFTED CONTROLLED VOLTAGE MODE AC/AC CONVERTERS WITH HIGH FREQUENCY AC LINK

An uni-polarity phase-shifted controlled voltage mode AC/AC converters with high frequency ac link based on Forward converter are initially proposed and deeply investigated.These converters are constituted of an input cycloconverter,a high frequency transformer,an output cycloconverter, and an input and output filters .The unsteady input AC voltage with high harmonic is modulated into bi-polarity three-state high frequency ac voltage by the input cycloconverter,bi-polarity three-state high frequency ac voltage is demodulated into uni-polarity three-state SPWM wave by the output cycloconverter ,and the uni-polarity three-state SPWM wave filtes into steady sinusoidal voltage with low harmonic. By using a phase shifting control between right and left both bridge legs, the output cycloconverter commutating while the bi-polarity three-state high frequency ac voltage from the input cycloconveter becomes zero,and commutation overlap of the output cycloconverter and polarity selection of the input voltage, the leakage inductance energy and the output filtering inductance current are naturally commutated , while ZVS switching of the output cycloconverter are realized. Twelve kinds of modes and equivalent circuits within one switching period are carefully analysed.The output characteristic and design criterion of key circuit parameters are given. The theoretical analysis is verified by a pricinple test.