分布式电源对配电网距离保护的影响及优化

The Influence and Optimization of Distributed Generation on the Distance Protection of Distribution Network

分布式电源并网后,传统配电网的继电保护受到重大影响,输电线路中的距离保护相对于配电网中的电流保护更加完善成熟。分析了不同容量的DG从不同位置并网时对3段式距离保护产生的不同影响,在此基础上,结合逆变型DG并网时的短路电流特性,分2种情况进行讨论分析考虑,即DG输出最大短路电流受限和不考虑DG输出最大短路电流受限的情况,并提出基于距离保护的DG优化策略。结合PSCAD仿真软件,通过某10 kV实际配电网进行仿真,验证了该方法的有效性和合理性。

The connection of distributed generation(DG)has a great impact on the relay protection of traditional distribution network.The influences on the three-step distance protection are analyzed when different capacity DG are connected to different positions of the distribution network.On this basis,combined with the short-circuit current characteristics of the inverter type DG connected to the grid,2 situations are discussed and considered,that is,the maximum short-circuit current of DG output is limited and the maximum short-circuit current of DG output is not considered,and the DG optimization strategy based on distance protection is proposed.The method is simulated by a 10 kV practical distribution network with the simulation software PSCAD,verifying the validity and rationality.