从光伏并网逆变器的内部结构和控制策略出发,首先分别建立了分布式光伏电源在单位功率因数、功率因数滞后性质和超前性质下的三种运行策略;然后,分析了其运行特性;最后,对光伏电源在不同运行策略下的短路暂态过程以及配电网静态电压分布情况进行了仿真分析。结果表明:光伏电源提供的短路电流可以控制在其额定电流的1.3倍以内;光伏电源在滞后功率因数运行时对配电网静态电压有支撑作用,而超前功率因数运行时可以有效缓解高电压越限的问题。
Based on the internal structure and control strategy of grid-connected PV inverter,three photovoltaic power operation strategies(unity power factor,lagging power factor and leading power factor)are established.Through simulation analysis of short circuit transient process and quiescent voltage of distribution network under different operation models,the following conclusions are drawn:the short-circuit current of photovoltaic power can be controlled within 1.3times of its rated current,and the photovoltaic power running under lagging power factor can be supportive for the voltage of distribution network,while the photovoltaic power running under leading power factor can solve the problem of voltage off-limit efficiently.