单相高频链正弦波逆变器的一种新拓扑

高频变压器一次侧H桥高频逆变产生MSPWM(Modified SPWM)脉冲波,MSPWM含有SPWM所有信息,但不含调制波的低频分量。二次侧采用倍流同步式周波变换器(CDSC)将其解调为常规的SPWM脉冲波,然后滤波得到需要的正弦波输出。这种全桥\CDSC结构,其特性不同于已有拓扑族中的任何一种。可以方便地实现双向开关、滤波电感的安全换流。无需依据负载电流的极性及换流重叠控制双向开关的换向。消除了该类变换器中固有的电压、电流过冲。拓扑结构简单,硬件投资少。文中分析了MSPWM脉冲波及CDSC输出的频谱特性,详细解析了新拓扑的工作模式。仿真和实验证实了理论分析的正确性及新拓扑的可行性。

A New Topology of Single-Phase Sinusoidal Inverter With High Frequency Link

A new topology of single phase sinusoidal inverter with high-frequency link(HF-L) is proposed.Modified SPWM(MSPWM) pulse sequence is generated by H bridge in primary side of the high-frequency transformer.The MSPWM includes the whole information of SPWM wave except modulation signal low frequency component.Conventional SPWM pulse sequence is demodulated by current doubler synchronous cycloconverter(CDSC) in secondary side.Finally,expectant sine-wave is obtained by filter from the SPWM.This full bridge、CDSC structure is different from prior any kind of this converter family in characteristics.As a result,filtering inductance and bidirectional switches can easily implement natural commutation.Commutation of devices will be independent of load current polarity and commutation overlap of CDSC.Innate voltage and current surge of this sort of converters is overcome.So,control structure can be simply,and hardware investment can be reduced.Spectrum characteristics of MSPWM and output of CDSC,the work principle are deeply analyzed,in this paper.Simulations and experiments show that the theory analysis is correct,and the new topology is feasibility.