距离保护在具有分布式电源的配电网系统中的应用

研究了分布式电源接入放射状配电网对配电网继电保护的影响。利用Matlab/Simulink建立了直接并网和逆变并网两种分布式电源模型,并对配电网进行距离保护整定计算。针对分布式电源的类型、容量和接入位置等因素,探讨了在有分布式电源接入的配电网系统中,电流速断保护和距离保护的工作情况。分析了运行中可能出现的问题,如长短线配合、短路点过渡电阻对测量阻抗的影响,并给出了相应解决办法。结果表明分布式电源对配电网继电保护的灵敏度,选择性有一定的影响。

Application Study of Distance Relay in The Distribution System With Distributed Generations

The effects of DG on the protection of radial distribution system are discussed.Two types of distribution generation (DG) models that are directly connected and connected through an inverter are built by Matlab/Simulink software.The setting value of the relay protection is calculated.According to the type,capacity and location of the distributed generation (DG),the working situations of the current protection and distance relay in the distribution system with DGs are studied.Questions that may appear in operation, such as the coordination in long-short line system,the impact of transition resistance are analyzed and corresponding solutions are also advanced.The result indicates DG has some influences on the sensitivity and selectivity of relay protection in the distribution system.