用于光伏低电压穿越测试的电压跌落发生器设计与试验

摘要

A general design scheme of voltage sag generators(VSGs)is proposed for low voltage ride-through(LVRT)test of photovoltaic (PV) systems.The VSG can also be adapted to a variety of power grid voltage levels.Based on the requirements of LVRT curve specified in the national standard GB/T 19964-2012,the working principle of the typical impedance-type VSG is expounded.A design method is then proposed for the topology structure and electrical parameters of current limiting reactor and grounding reactor of a VSG.Furthermore,a design example of VSG at 10 kV voltage rating is given.The VSG has 20 different sag depths ranging from 0% to 100% of rated voltage with the step of 5%.Finally,for a grid-connected 500 kW PV inverter,the single-phase and three-phase voltage sag tests with several sag depths,especially 0%,are conducted and the test results prove the effectiveness of the design scheme.%针对光伏低电压穿越测试,提出一种能适应多种电网电压等级的电压跌落发生器通用设计方案。依据国家标准 GB/T 19964-2012中规定的低电压穿越曲线要求,阐述了典型阻抗形式电压跌落发生器的工作原理；提出一种该电压跌落发生器中限流电抗器和接地电抗器的拓扑结构及电气参数设计方法；给出一个电压等级为10 kV,且可以5%步长实现从0%至100%电网额定电压的全范围20种电压跌落深度的电压跌落发生器设计实例。最后,针对一台500 kW光伏并网逆变器,进行了多种深度尤其是零电压穿越的单相和三相跌落试验,试验结果证明了该方案的有效性。