考虑规模化电动汽车负荷的柔性台区安全经济运行边界

柔性台区将若干个传统交流台区通过柔性装置互联,能够充分利用各台区变压器的容量,提升对电动汽车的接纳能力。文中首先针对柔性台区建立了一维安全经济运行边界模型,并提出采用安全裕度百分数作为度量机制,为调度人员提供直观的系统运行状态和安全裕度,实现主动调度。进一步地,基于凸包络构建柔性台区的二维安全经济运行域模型,方便调度人员对多个充电站进行协同管理。仿真结果表明,安全经济运行边界能够同时计及系统的安全性和经济性,可拓展性强;经济指标对安全经济边界的形态有较大影响;柔性台区中的直流充电桩和交流充电桩的安全经济运行边界具有不同的形态;基于凸包络的二维安全经济运行域模型能够有效反映系统运行状态的安全性和经济性。

Security-economy operational boundary of flexible district considering large-scale EV charging loads

Flexible district, which interconnects several AC districts through the flexible devices, is able to make full use of capacity of transformers and to cope with large-scale EV charging loads. The coupled districts could be co-operated and hence enhancing both the security and economy. This paper firstly constructs the security-economy operational boundary for the flexible district and then proposes the concept of security margin percentage. Furthermore, we construct the convex-hull based two-dimensional security-economy region to promote the co-operation among numerous charging stations. Numerical results demonstrate both the extensibility and the practicality of the proposed security-economy operational boundary. Besides, numerical results reveal that economic index has strong influence on the shape of security-economy operational boundary, and that the boundary shape for AC charging station and DC charging station are different.#$NLKeywords: distribution district low voltage interconnection; fast charging load of electric vehicle; security operational boundary; economy operational boundary; AC-DC distribution network