一种能够抑制共模电流的单级单相Buck-Boost光伏逆变器

A SINGLE-STAGE SINGLE-PHASE BUCK-BOOST PV INVERTER WHICH CAN SUPPRESS LEAKAGE CURRENT

该文给出一种能抑制共模电流的单级单相Buck-Boost光伏逆变器,该逆变器是通过将H桥逆变器与Buck-Boost斩波电路级联以及对相关的元件进行复用并对电路进行简化得到的,可同时实现升降压以适应宽输入范围的直流侧电压,无电解电容应用且具备有效抑制漏电流的能力,保证系统的可靠性和安全性,非常适用于中小功率光伏系统。此外,利用一种基于调制波重构的非线性调制策略,能显著降低直流侧储能电感大小,有效提高功率密度,实现均衡升降压。详述其工作原理,通过共模分析验证其能对阴阳两极漏电流实现有效抑制以及新型调制策略下可实现均衡升降压控制。在理论分析基础上,完成逆变器并网控制的仿真和实验,结果与理论分析相契合。

This paper presents a single-stage single-phase buck boost photovoltaic inverter which can suppress common mode current the inverter is obtained by cascading H-bridge inverter with buck boost chopper circuit,reusing related components and simplifying the circuit. It can simultaneously achieve voltage up and down to adapt to the wide input range of DC side voltage,without electrolytic capacitor application,and has the ability to effectively suppress leakage current,ensuring the reliability and safety of the system,It is very suitable for small and medium power photovoltaic system. In addition,a nonlinear modulation strategy based on modulation wave reconstruction can significantly reduce the size of the DC side energy storage inductor,effectively improve the power density,and achieve balanced voltage up and down. The working principle is described in detail,and the common mode analysis shows that it can effectively suppress the leakage current of the anode and cathode,and realize the balanced voltage up and down control under the new modulation strategy. Based on the theoretical analysis,the simulation and experiment of grid connected inverter control are completed,and the results are consistent with the theoretical analysis.