一种新型低漏电流光伏并网逆变器的研究

A New Grid-tied Photovoltaic Inverter With Low Leakage Currents

提出了一种新型低漏电流非隔离光伏并网逆变器,该拓扑具有优秀的共模电压箝位效果,以及低的共模电流水平。在逆变电感续流时,提供一条两个开关管的续流回路,通过另一个开关管将电路桥臂中点对直流母线负端的电位箝位在1/2光伏阵列输出电压。通过一种有效的驱动逻辑,实现了两个续流开关管和箝位开关管的软开通。详细分析了该拓扑的各个工作模态,并与几种常用的非隔离光伏并网逆变器拓扑进行了比较。通过与Heric拓扑的对比实验证明了该拓扑的有效性和低的共模电流水平。

A novel non-isolated grid-tied photovoltaic inverter with low leakage currents is proposed.This topology can better suppress common-mode current and voltage.Two power switches provide freewheeling loop for the inductor current.This clamp the voltage between the midpoint of bridge arm and the negative DC bus terminal to 1/2 output voltage of photovoltaic array,and also separate the solar panel from power grid.The soft switching of two transistors can be achieved by using a valid drive logic.All operating modes were analyzed compared with that of traditional ones.And an experiment compared with Heric topology verifythe validity and low common-mode current.