一种新型单相非隔离型光伏并网逆变器研究

Research on a Novel Single-phase Non-isolated PV Grid-connected Inverter

针对传统单相非隔离型全桥光伏并网逆变器的不足,研究并设计了一种新型、高效率且具备漏电流抑制能力的两级式单相非隔离型光伏并网逆变器。该逆变器拓扑电路由前级Boost变换器与后级H6结构逆变拓扑级联而成。电流控制环采用比例谐振(PR)控制器来无静差跟踪给定的正弦电流,以提高并网电流质量。最后,通过一台2 kW的单相光伏并网逆变器样机,对理论分析结果进行了实验验证,结果表明该新型单相非隔离型光伏并网逆变器具有控制简单,变换效率高,可靠性高等优点。

In order to inhibit leakage current of traditional single-phase full-bridge photovoltaic inverter,a novel and high efficiency two-stage single-phase non-isolated photovoltaic inverter with ability of alleviating leakage current is analyzed and designed.This topology circuit is cascaded by a pre-stage of Boost converter and the second-stage of H6 topology.A proportional resonant（PR） regulator is adopted in the current-loop to track the given sinusoidal current to im- prove the quality of grid-connected current.Finally, a 2 kW prototype of single-phase grid-connected inverter is set up to verify theoretical analysis results.Experimental results verify that this novel single-phase non-isolated photovohaic grid-connected inverter features simple control, high efficiency and high power quality.