面对配电网供电需求的增大、连接复杂度的增高以及可再生能源接入等问题，研究和发展智能配电网保护控制成为电力系统发展的必然选择和趋势。提出基于广义节点的配电网集中式差动保护方法，根据电网实时结构和测量可用性变化情况，应用广义节点的概念，确定差动保护的最小差动区间，即一个由保护终端构成的、封闭的合围若干电气元件的最小集合。基于广义基尔霍夫定律建立了数学模型，给出了计算方法，通过算例分析验证了该算法的可行性，可以解决分布式电源接入以及出现部分环网情况下配电网的保护问题。%The research and development of protection control in intelligent distribution network become the inevitable outcome and the development trend of electric power system with the increase of demand in power supply demand, increased strength of connection complexity and access of renewable energy access. This paper puts forward the method of distribution network centralized differential protection based on the concept of generalized node in distribution network. It applies the concept of generalized node to determine the minimum differential interval of differential protection, namely the minimum set of electrical components composed by the protection terminal and being in closed and encircled status, according to the power grid structure and real-time measurement available. This paper establishes the mathematical model based on the generalized Kirchhoff's law , and gives the calculation method. Numerical results of calculating examples show that the proposed algorithm is feasible and the method can solve the problems of DG access and the protection of the distribution network included the ring network circumstances. This work is supported by National Natural Science Foundation of China (No. 50977017).
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