长时间尺度下计及光伏不确定性的配电网无功优化调度

针对高渗透率分布式光伏接入配电网所引起的电压控制问题,分析了无功补偿型和电压控制型两种光伏发电系统的无功电压调控特点,在考虑负荷和光伏出力不确定性的基础上,以系统总运行成本最小为目标,提出了长时间尺度下考虑电压越限风险的配电网无功优化调度模型。针对电压控制型光伏无功电压调控特点,提出了含PV类型节点的配电网概率潮流计算方法。最后,通过时间解耦并采用灾变遗传算法求解得到含高渗透率光伏的配电网长时间尺度下的无功优化调度方案。仿真算例表明:与现有光伏无功控制方法相比,所提方法能够有效降低光伏并网引起的电压越限风险,其中基于电压控制型光伏的配电网无功调度方案在降损和抑制电压波动方面的控制效果更明显。

Optimal Reactive Power Dispatch with Long-time Scale in Distribution Network Considering Uncertainty of Photovoltaic

In order to deal with the voltage control problem caused by the distributed photovoltaic(DPV)of high penetration level, the voltage control characteristics of the reactive power compensated PV and the voltage-controlled PV are analyzed. Considering the uncertainty of the output of load and DPV, an optimal reactive power dispatch(ORPD)model with long-time scale in distribution network considering the risk of voltage violation is proposed to minimize the operating cost. A probabilistic power flow calculation method in the distribution network is proposed, which contains PV nodes in order to solve the control problem caused by the voltage-controlled PV. The ORPD model aforementioned can be solved by the time decoupling and the catastrophic genetic algorithm. The simulation results show that the proposed method is able to effectively reduce the risk of voltage violation when compared with the existing DPV reactive power control methods. The ORPD scheme based on the voltage-controlled PV has a more significant effect on reducing the operation loss and suppressing the voltage fluctuation.