计及电压越限风险的含分布式光伏配电网三相载荷不平衡多目标优化方法

IMBALANCE MULTI-OBJECTIVE OPTIMIZATION METHOD OF THREE-PHASE LAOD FOR DISTRIBUED PHOTOVOLTAIC POWER DISTRIBUTION NET WORK CONSIDERING RISK OF VOLTAGE OVERRUN

针对含分布式光伏中低压配电网的三相载荷不平衡问题,提出一种计及电压越限风险的含分布式光伏配电网三相载荷不平衡多目标优化方法。以三相不平衡度综合指标、电压越限指标和优化动作复杂度指标为最小化优化目标,构建面向分布式光伏和用户的三相载荷不平衡多目标优化模型。提出日前-日内两阶段优化算法,通过将多目标问题转化为单目标问题求解得到的最优解作为先验知识的方式,对NSGA-Ⅱ算法初始种群的选取方法进行改进,然后采用改进的NSGA-Ⅱ算法对多目标问题进行全局寻优。最后仿真分析,验证了该文所提优化方法能显著改善中低压配电网的三相载荷不平衡问题,同时能有效抑制分布式光伏带来的系统电压越限风险。

In order to solve the three-phase imbalance problem of medium and low voltage distribution network with distributed photovoltaics,a three-phase imbalance optimization method for distribution network considering the risk of voltage overrun is proposed.Taking the three-phase imbalance comprehensive index,voltage overrun risk index and optimization complexity index as the minimizing optimization goals,a three-phase imbalance multi-objective optimization model is constructed.A two-stage optimization algorithm of dayahead and day-during is proposed,and the prior knowledge is obtained by solving the single-objective optimization problem converted by the original multi-objective problem,which improves the traditional NSGA-Ⅱalgorithm in the selection way of the initial population,then the multi-objective problem can be optimized by the improved NSGA-Ⅱalgorithm.Finally,through analyzing the simulation results,the optimization method proposed in this paper can significantly improve the three-phase imbalance problem of medium and low voltage distribution network,and at the same time effectively suppress the risk of voltage overrun of the system caused by distributed photovoltaics.