计及分布式光伏和储能主动支撑的配电网日前日内协调优化运行策略

Coordinated Optimal Strategy for Day-Ahead and Intra-Day Operation of Distribution Network Considering the Active Support of Distributed Photovoltaic and Energy Storage System

为充分挖掘分布式光伏与储能对配电网的主动支撑能力,提高配电网运行效益与供电质量,提出计及分布式光伏和储能主动支撑的配电网日前日内协调优化运行策略。考虑到光伏和负荷预测误差所带来的调度成本风险,采用条件风险价值的方法对其进行量化。日前优化模型以配电网运行成本与成本风险最小为优化目标,制定日前优化方案,为日内优化提供参考;日内优化模型对分布式光伏与储能的有功无功功率进行调度,以加权电压偏差、线路损耗、储能有功功率偏差最小为优化目标,在提升配电网供电质量的同时保证日内运行的经济性。将所提出的模型转化成便于求解的二阶锥规划模型,采用IEEE 33节点算例对所提出的策略进行验证。算例结果表明,所提出的日前日内协调优化策略充分挖掘了分布式光伏与储能的主动支撑能力,有效降低了配电网的运行成本,并对电压越限问题有明显的缓解作用。

In order to fully excavate the active support capability of distributed photovoltaic(PV)and energy storage system(ESS)and improve the economic benefits and power supply quality of the distribution network,a coordinated optimal strategy for day-ahead and intra-day operation of distribution network considering the active support distributed PV and ESS is proposed.Considering the dispatch cost risk caused by PV and load prediction error,the conditional value-at-risk(CVaR)method is used to quantify the cost risk.Day-ahead optimization model takes the minima of operation cost and cost risk of distribution network as the optimization objec⁃tive,and formulates day-ahead optimization scheme to provide reference for intra-day optimization.The intra-day optimization model dispatches the active and reactive power of PV and ESS.The minimum weighted voltage deviation,the line loss and the ac⁃tive power deviation are taken as the optimization objective to improve the power supply quality of the distribution network to ensure the economy of intra-day operation as well as improve the quality of power supply in the distribution network.The proposed model is transformed into a two-order cone programming model which is easy to solve,and the proposed strategy is verified by an IEEE 33 node example.Results show that the proposed coordinated optimal strategy fully exploits the active support capability of PV and ESS,ef⁃fectively reduces the operating cost of the distribution network,and has an obvious easing effect on the voltage violation problem.