微网并网与孤岛运行模式下的无功优化策略

Reactive Power Optimization Strategy for Microgrid in Grid-Connected and Islanded Operation Modes

高渗透率的间歇性分布式电源(DG)使微网在并网或孤岛模式的运行可靠性降低,而传统的无功优化方法往往因忽略微网可靠性导致优化效果较差。依据有功及无功功率充足和电压极限限制,以概率方式来评估微网的可靠性,提出了一种微网在并网及孤岛模式下的无功优化规划模型,以系统年电能损耗最小和微网可靠性最大为目标进行求解。最后,采用PG&E 69节点进行算例分析,研究了优化系数的作用效果和算法的鲁棒性,并通过成本-效益分析来确定系统的电容器组的最优容量。结果表明,对微网进行分布式无功电源的优化配置能有效改善网损,并提高系统的可靠性。

High permeability intermittent distributed generation(DG)reduces the reliability of microgrid in grid-connected or island mode,while the traditional reactive power optimization methods often neglect the reliability of microgrid,resulting in poor optimization results.The reliability of microgrid is assessed in a probabilistic manner according to the sufficient active and reactive power and voltage limit limits.A reactive power optimization planning model of micro-grid in grid-connected and island mode is proposed,which aims at minimizing the annual power loss and maximizing the reliability of micro-grid.Finally,an example is given by using PG&E 69 nodes.The effect of the optimization coefficient and the robustness of the algorithm are studied,and the optimal capacitor capacity of the system is determined by cost-benefit analysis.The results show that the optimal configuration of distributed reactive power supply in microgrid can effectively improve the network loss and the reliability of the system.