新型单级升降压并网逆变器的研究

Study on Novel Single-stage Boost-Buck Grid-connected Inverter

针对于小型分布式发电机输入源变化范围较大的问题,提出一种新型三开关器反激式单级单相升压降压逆变器拓扑结构。对该逆变器进行了系统的数学建模,阐述了其工作原理和电流控制策略,比较了DCM和CCM控制模式的区别,提出了闭环SPWM调制策略。该逆变器能够实现独立负载运行和并网发电运行,且具有器件最少、控制简单和效率高等优点。最后通过仿真和实验表明,对该逆变器的数学分析是正确可行的,且能够实现独立负载和并网运行。

Considering that the input source of a small distributed generator usually varies widely,a topology configura-tion of a novel single-stage boost-buck flyback inverter composed of three switches is proposed. Through the mathematical modeling of the inverter,its operation principle and current control strategy are illustrated. The difference between discontinuous conduction mode（DCM）and continuous conduction mode（CCM）is compared,and a closed-loop sinusoidal pulse width modulation（SPWM）strategy is proposed. The inverter can realize standalone load and grid-connected operations,and it has advantages such as least switches,simple control and high efficiency. Finally,simulation and experimental results show that the mathematical analysis of the converter is correct and feasible,and the standalone load and grid-connected operations can be realized.