含分布式电源配电网保护方案

分布式电源（DG）接入配电网会对传统的配电线路电流保护产生影响，可能导致保护不正确动作。针对这一问题，文中提出一种新的保护方案，对传统的配电线路保护配置进行了改进。该保护方案根据DG接入点的位置，对被保护馈线进行了分区，在DG的上游区域配置了方向纵联保护，而整条馈线则保留了过电流保护。为了能方便整定工作以及更快地切除故障，根据DG接入位置的不同，馈线的过电流保护分别采用定时限或反时限形式。采用该保护方案后，无论DG的输出功率如何变化，故障都能被可靠切除。最后，对一个10 kV配电系统进行了仿真，验证了保护方案的有效性。

A Protection Scheme for Distribution System with Distributed Generations

When distributed generation(DG)is connected to the distribution system,it may have some effect on the traditional current protection and lead to the protection of maloperation.By improving the traditional protection configuration,a new protection scheme is introduced to solve this problem.According to the connected point of DGs,the protected feeders are divided into different zones,with directional pilot protection configured at the upstream side of DG and the overcurrent protection retained for the whole feeder.In order to make the value setting convenient and the fault clearing quick,the definite-time or inverse-time overcurrent protection is adopted for the feeders based on different locations of DGs.No matter how the output power of the DG changes,the fault can be reliably cleared with this protection scheme.Simulation results on a 10 kV distribution system have verified the validity of the scheme proposed.