基于改进模拟退火-粒子群的配电网分布式光伏承载力评估

Evaluation of distributed photovoltaic hosting capacity of distribution networks based on improved simulated annealing-particle swarm optimization

大规模分布式光伏并网给中压配电网带来严重功率反送,导致中压配电网出现节点电压越限和配电变压器反向过载问题.以系统潮流平衡、节点电压偏差、配电变压器反向负载率和线路载流量为约束条件,以分布式光伏并网容量与系统网络损耗之差的分布式光伏等效并网容量为目标函数,建立中压配电网分布式光伏承载力评估模型,并提出改进模拟退火-粒子群(SA-PSO)算法.对IEEE33系统和实际中压配电网进行分布式光伏承载力计算,结果表明,所建立的分布式光伏承载力评估模型适用于中压配电网节点电压稳定性与配电变压器安全运行问题评估;相较于其他算法,改进SA-PSO算法提高了评估模型计算的收敛速度与寻优能力,在相同约束条件限值下,所得线路分布式光伏承载力更高,且系统网络损耗更低.

Large-scale distributed photovoltaic grid-connection has brought serious power back-feeding to the medium-voltage distribution network,resulting in node voltage limit violations and reverse overload of distribution transformers in the medium-voltage distribution network.An evaluation model for distributed photovoltaic hosting capacity in medium-voltage distribution networks was established,and an improved simulated annealing-particle swarm optimization(SA-PSO)algorithm was proposed.The system power flow balance,node voltage deviation,reverse load rate of distribution transformers,and line current carrying capacity were taken as constraints,and the distributed photovoltaic equivalent grid-connection capacity was taken as the objective function,which was the difference between the distributed photovoltaic grid-connection capacity and the system network loss.The distributed photovoltaic hosting capacity calculation was performed on the IEEE33 system and an actual mediumvoltage distribution network.Results showed that the established distributed photovoltaic hosting capacity evaluation model was suitable for evaluating the stability of node voltage and safe operation of distribution transformers in medium-voltage distribution networks.Compared with other algorithms,the improved SA-PSO algorithm improved the convergence speed and optimization ability of the evaluation model calculation.Under the same constraints,the obtained line distributed photovoltaic hosting capacity was higher and the system network loss was lower,compared with those of other algorithms.