电力系统变配用协同分级保护分析与应用研究

电力系统继电保护是保障电网安全稳定运行最重要的防线,电力系统能量传输网络根据功能的不同可以分为发、输、变、配、用等多个环节,各个部分均存在保护装置。当用户侧发生故障时,由于保护之间配置的不匹配,经常会出现越级跳闸的情况,导致故障扩大甚至造成电网的裂解。尤其是当前配电网高比例可再生能源渗透下对继电保护的协同分级配合提出了更高的要求,配电网的故障特征发生了明显的改变。本文在考虑分布式电源并网对电力系统变配用分级保护的影响的基础上,首先讨论逆变型分布式电源的运行特性,重点讨论了其控制方式和低电压穿越能力,其次分析分布式电源接入配电网故障特征,分上游、下游和相邻馈线分析分布式电源对电力系统继电保护的影响,尤其是变、配、用保护之间的协同配合问题,提出了低电压穿越矩阵、用户分支系数矩阵和分布式电源系数矩阵并给出了他们之间的相互关系公式。最后,针对提出的电力系统协同分级保护优化方法进行实例分析,证明了所提方法的有效性与科学性。

Analysis and application of cooperative hierarchical protection for power system transformation, distribution and consumption

Power system relay protection is the most important defense line to ensure the safe and stable operation of the power grid. According to different functions, the power system energy transmission network can be divided into multiple links, such as generation, transmission, transformation, distribution and user, and each part has protection devices. When a fault occurs on the user side, due to the mismatching of the configuration between the protections, there will often be leapfrog tripping, resulting in the expansion of the fault and even the cracking of the power grid. In particular, under the current high proportion of renewable energy penetration in the distribution grid, higher requirements are put forward for the coordination and classification of relay protection, and the fault characteristics of the distribution network have changed significantly. Based on the consideration of the influence of the grid connection of distributed generation on the hierarchical protection of power system transformation and distribution, this paper first establishes calculation models for the distributed generation, then analyzes the fault characteristics of the distributed generation connected to the distribution grid, and discusses the influence of distributed generation on the relay protection of power system, especially the coordination among transformation, distribution and user protection.? Finally, an example of the proposed collaborative hierarchical protection optimization method for power system is analyzed, which proves the effectiveness and scientificity of the proposed method.