Distributed generators are usually connected via distribution network, which makes revolutionary change of the radial structure of distributed network. A series of problems, such as voltage regulation, reactive power balance and relay protection, will have effect on power system operation. 分布式电源大多通过配电网接入系统,这使得原有的辐射形配电网单向电源馈电潮流特性发生了根本性变化,一系列包括电压调整、无功平衡、继电保护在内的问题都将影响系统运行。