主动配电网低压分布式光伏连锁故障分析

分布式光伏发电系统大规模离散式接入配电网的趋势日益明显,电网节点光伏渗透率升高,功率传输流向发生改变,影响配电网电压分布。含分布式光伏发电系统的主动配电网模型通常是在单一节点处并联等效光伏电源模型,难以体现分布式电源离散性分布的特点。为此,建立含低压分布式光伏发电系统的主动配电网仿真模型,模拟低压分布式光伏系统脱网所引发的配电网电压波动以及各节点分布式电源连锁故障。基于牛顿-拉夫逊法潮流计算原理,提出关于节点功率变化对配电网电压分布影响的分析方法;仿真结果表明,低压分布式光伏发电系统连锁故障的分析方法能够较为准确地描述相应主动配电网在电压跌落情况下的连锁故障情况。

Analysis of Low Voltage Distributed Photovoltaic Cascading Failure in Active Distribution Network

The trend of large-scale discrete access of distributed photovoltaic power generation system connected to the distribution network is growing obviously.The penetration level of distributed photovoltaic generation has increased,and the power distribution network may feed power into the transmission network,affecting the voltage distribution of the network.Scholars usually set up a parallel equivalent photovoltaic power model at a single node in the active distribution network model,which is difficult to reflect the discrete distribution characteristics of photovoltaic distribution generation.To this end,an active distribution network simulation model with high-penetrationlow-voltage distributed photovoltaic generation system is established to simulate the voltage fluctuation and the cascading failure of the distribution network caused by the disconnection of the distributed photovoltaic generation system and the cascading failure of distributed generation at each node.Based on the Newton-Raphson method of power flow calculation principles.The simulative results show that the proposed analysis method of cascading failures can more accurately describe the cascading failures of the active distribution networks with high-penetrationlow-voltage distributed photovoltaic generation system under large disturbances voltage drops.