含间歇电源、储能和电动汽车的配电孤岛短时恢复供电策略

电力系统发生停电事故后,含有分布式电源和储能系统的配电系统可以形成孤岛运行的微网,在短时间内为微网内的停电负荷恢复供电。然而,风电和光伏等间歇性电源的发电出力具有不确定性,难以对孤岛内负荷进行持续、稳定供电。在此背景下,提出了计及间歇性电源出力不确定性的配电系统恢复优化模型。首先,考虑含有分布式电源、储能系统和可控负荷的配电系统,针对停电事故发生后一个较短时段内的供电恢复问题,提出了以最大化恢复供电的负荷用电量为目标的配电系统恢复模型。之后,分析各种分布式电源的出力特性和供电能力,并利用可控负荷平衡间歇性电源出力波动。考虑到间歇性电源出力的不确定性,利用概率模型对其出力预测值进行处理,这样就避免了在模型求解时再处理不确定性因素,从而可将配电系统恢复模型转换为混合整数二次规划问题并用CPLEX求解器求解。最后,以修改的IEEE 33节点配电系统为例,对所提出的模型和方法进行了验证。

Short-period Restoration Strategy in Isolated Electrical Islands with Intermittent Energy Sources, Energy Storage Systems and Electric Vehicles

A distribution system with distributed generators, energy storage systems and electric vehicles can be operated as an isolated microgrid and provide power supply to the interrupted loads in a short period after a fault-caused power supply interruption. However, as the output power of an intermittent energy source such as a wind turbine or a photovoltaic panel is generally fluctuant and stochastic, it is hardly possible to provide sustainable power supply to the power loads in the isolated island operating as a microgrid. Given this background, a strategy for short-period restoration of the isolated island considering the power output uncertainties of intermittent energy sources is presented. A restoration model for the isolated island with distributed generators, energy storage systems, electric vehicles and controllable loads is developed first, with the objective of providing continuous and stable power supply to the maximized amount of power load in a given period. The characteristics of different kinds of intermittent energy resources and their output capabilities are discussed next, and the controllable loads are employed to balance the power output fluctuations of these intermittent energy sources. Probabilistic models are utilized to describe the uncertainties of the predicted power outputs of the intermittent energy sources. The proposed restoration model is then transformed to a definite quadratic constrained integer programming one, and solved by the well-developed CPLEX solver. Finally, the proposed restoration strategy is verified by a modified IEEE 33-bus test system. This work is supported by National Basic Research Program of China (973 Program) (No. 2013CB228202), National Natural Science Foundation of China (No. 51361130152, No. 51377005) and Zhejiang Key Science and Technology Innovation Group Program (No. 2010R50004).