含分布式电源的配电网过电流保护机制

Overcurrent protection scheme in distribution network with distributed generation

分布式电源接入配电网给继电保护机制带来了新的问题,甚至导致保护装置误动作。而保护装置的可靠性和安全性需要保护元件的最优配合,在分布式电源接入之后,需要考虑分布式电源对保护装置配合的影响。本文提出了一种在含有分布式电源电网中的保护装置的配合机制。首先说明了分布式电源对继电保护动作范围的影响。然后建立了以保护动作时间最小为目标,考虑配合时间阶段、保护动作时间、每个保护装置时间整定倍数、启动电流、保护特性等约束的优化模型。接着根据IEC 60909标准对不同位置节点的短路电流进行计算,并利用差分进化算法对本文所建模型进行求解。最后在IEEE14节点中进行仿真分析,说明了本文所提方法的正确性和有效性。

The access of distributed generation to the distribution network brings new problems to the protection relay,and even causes the protection device to malfunction.The reliability and security of the protection device require the optimal coordination of the protection components.After the distributed power supply is connected,the influence of the distributed power supply on the cooperation of the protection device needs to be considered.A coordination scheme is proposed for protection relay in distribution network.First,the influence of distributed power supply on the range of relay operation is explained.Then,an optimization model is established with the minimum protection action time as the goal,considering the constraints of the time coordination,the protection operation time,the time multiplier setting of each protection device,the pickup current,and the protection characteristics.Then the short-circuit currents of different location nodes are calculated according to IEC 60909 standard,and the differential evolution algorithm is used to solve the model.Finally,simulation analysis is carried out in IEEE14 nodes,which illustrates the correctness and effectiveness of the proposed method.