具备高压解耦电路的新型无电解电容微逆变器研究

A Novel Electrolytic Capacitor-less Micro-inverter with High Voltage Gain Power Decoupling Circuit

提出了一种新颖的单相无电解电容光伏并网微逆变器。该微逆变器主电路拓扑由光伏器件输出侧功率解耦电路和反激式逆变器构成。解耦电路将光伏器件输出能量储存在高电压电容中,以减小解耦电容容量,实现小容量薄膜电容替代大容量电解电容。反激式变换器以薄膜电容为主要电源,避免光伏器件工作受逆变干扰,简化了微逆变器控制策略。同时,详细分析微逆变器电路的工作原理,并阐述电路主要参数的设计依据。最后,搭建一台100W并网微逆变器样机,实验结果验证了所提出微逆变器及控制策略的有效性。

A novel micro-inverter topology without electrolytic capacitor is proposed, which is applied in a single stage photovoltaic power conversion system. The topology is based on a conventional flyback combining with decoupling circuit located in the photovoltaic module output side. The power decoupling circuit can store the PV output power in high voltage capacitor, which reduces the decoupling capacitance, thus allowing for long lifetime film capacitor to be used. The flyback inverter uses the film capacitor as main power source and avoids interference with the photovoltaic module, which simple the control strategy of micro-inverter. Operation principle of the novel micro-inverter is analyzed in detail and the design principle of the main parameters is presented in this paper. A 100W prototype of the proposed micro-inverter has been built and tested. Experimental results are provided to demonstrate the validity of the proposed circuit and its control scheme.