多应用场景低压配网无缝合环转电解决方案

合环转电作为一种重要的网络重构技术,对提高配电网运行的可靠性与经济性具有重要意义。常规合环转电不仅存在合环冲击,而且合环点的选取受到两侧电源相角差的限制。文章针对广州配电网存在的大角度差不停电转供技术难题,提出两种无缝合环转电解决方案,分别是基于串并联补偿的合环方案和基于背靠背拓扑的合环方案。它们能够适用于多种转供场景,并提供交、直流两种转供电源接口。文章给出了每种方案的接线方式,对它们的结构特点、性能参数以及工作原理进行了分析。为了适应配电网三相不平衡与谐波污染的运行环境,从结构与控制两方面提出了装置的改进措施。最后,仿真验证了几种典型场景下无缝合环转电装置的运行原理,从而为实际开展低压无缝合环转电提供计算支撑。

Solutions for Seamless Closed-Loop Load Transfer of Low-Voltage Distribution Network in Multiple Application Scenarios

As an important network reconfiguration technology, the closed-loop load transfer (CLLT) is of great significance to improve the reliability and economic efficiency of the distribution network. The conventional CLLT has a loop closing impact and the selection of loop closing point is limited by the phase angle difference between two substations. In this paper, two solutions are proposed to solve the technical problems of CLLT with the large angle difference in the Guangzhou distribution network, which are based on series-parallel compensation and back-to-back topology, respectively. They can be applied to a variety of scenarios and provide AC and DC interfaces. The wiring modes of these schemes are given, and their structural characteristics, performance parameters, and operating principles are analyzed. To adapt to the condition of three-phase imbalance and harmonic pollution, the improvement measures of the two schemes are proposed from the structure and control perspective. Finally, the operating principle of the seamless CLLT device in several typical scenarios is verified by simulation, thus providing computational support for the actual development of seamless CLLT.