计及储能及负荷转供协同调度的城市电网弹性运行策略

Flexible operation strategy of an urban transmission network considering energy storage systems and load transfer characteristics

随着多种新型负荷的不断增长及新能源的大规模接入,城市配电网输电阻塞问题日益频繁,严重威胁电网安全运行和可靠供电。利用高压配电网网架重构以及储能电站充放电特性,实现负荷及发电的时间-空间转移,可有效缓解城市输电网局部阻塞问题,降低负荷损失,保证供电可靠性。因此,提出了一种同时考虑高压配电网重构和储能电站充放电协同控制的弹性运行策略。首先,建立了储能电站充放电功率调度模型及高压配电网可重构模型。然后,定义安全距离作为安全裕度指标,将线路传输容量和网络拓扑结构结合,以全面评估所提协同控制策略对提升220 kV电网运行安全的效果。最后以我国某城市局部高压配电系统为算例验证所提协同控制的有效性。结果表明,所提方法能有效均衡大尺度时空范畴内的源荷分布,改善城市输电网运行阻塞问题,提升220 kV输电网安全裕度。

With the growing multiple types of electricity load and greater integration of new energy into a power grid,congestion in and urban distribution network becomes more serious.This threatens the security of the power grid and the reliability of power supply.The local congestion of the urban transmission network can be alleviated by the spatial load transfer characteristics of high voltage distribution network reconfiguration and time load transfer characteristics of charge/discharge of battery energy storage systems.Thus,a coordinated dispatch strategy considering both these strategies is proposed.First,the model of the distributed network reconfiguration and the flexible scheduling model of a battery energy storage system are introduced.Then security distance is defined as the security index,which combines the available transmission capacity and topology to assess the effect of the proposed coordinated dispatch strategy comprehensively.Finally,a local high voltage distribution network of a city is used to verify the effectiveness of the proposed coordinated dispatch strategy.The simulation results show that the proposed method can improve the distribution of source and load over a large temporal-time scale.It is an effective way of alleviating congestion and promoting the security margin of a 220 kV transmission network.