计及网损最小的含分散式风电场配电网多目标优化策略

Multi-Objective Optimization Strategy of Distribution Network Containing Dispersed Wind Farm Considering Minimum Network Loss

提出一种计及网损最小的含分散式风电场配电网多目标优化策略。首先,提出了含分散式风电场配电网的3层功率控制系统,该系统整定层通过对比网损减小值和接入点功率损失值,判断采用恒功率因数为1控制或基于网损最小的多目标优化控制,以便灵活控制分散式风电场有功及无功功率主动参与配电网经济运行。其次,提出2个表征电网损耗的指标:有功网损率和无功网损率,并给出了基于权重的多目标网损最小的优化函数,求解得到最优有功功率和功率因数值。最后,分析了分散式风电场并网后对配电网电压稳定裕度的影响,并通过算例验证了证明所提策略可有效减小配电网网损,提高接入点电压水平,增强电网电压稳定裕度。

Dispersed wind power integration can improve voltage stability and loadablity of distribution network（DN）. Nevertheless, it is a challenge to traditional power grid scheduling mode with non-reasonable control. In order to solve technical problems of economic and stable operation, a multi-objective optimization strategy of DN containing dispersed wind farms（DWF） considering minimum network loss was put forward. Firstly, a three-layer power control system of DN containing DWF was proposed. The multi-objective optimization power control based on minimum network loss and constant power factor control based on maximum power output was proposed for setting layer. Comparison of network loss reduction with power loss for point of interconnection（POI） was used for judgment deciding strategy to be employed. As a result, DWF active and reactive powers can be flexibly controlled to participate actively in DN economic operation. Secondly, two optimal indices characterizing network loss, i.e. active and reactive power network loss rates, were proposed. A method was given to solve multi-objective optimization function based on weighting for optimal active power and power factor（PF）. Finally, the effect of DWF on DN voltage stability margin was analyzed. Engineering example shows that proposed strategy reduces DN power loss effectively, improves voltage level of POI and enhances loadability.