配电网中分布式电源的选址定容和电流保护策略

反时限过电流保护常用于配电网的线路保护,而不同容量的分布式电源接入配电网的不同馈线不同区段时,会对原有配电网的继电保护及安全运行产生很大的影响。文中分析了逆变型分布式电源对传统反时限过电流保护的配合特性和动作行为的影响,给出了基于反时限过电流保护的选址定容方法并指出其局限性。在此基础上,研究了故障限流器在电网故障时呈现的高阻抗特性,提出了一种基于故障限流器的含分布式电源的配电网保护策略,并结合福建省湄洲岛储能电站实例,建立PSCAD仿真模型,进行计算验证。仿真结果表明,所述方法能够有效降低逆变型分布式电源对反时限过电流保护的影响,使配电网线路的保护具有良好的协调性,保证配电网的稳定运行。

Locating and Sizing of Distributed Generators and Current Protection Strategy in Distribution Networks

When different capacities of distributed generations (DGs) are connected to different parts of distribution network, they have a great impact on protection, especially time inverse over current protection that is commonly used in the distribution network. The various influences of the inverter-based distributed generations on the properties and action feature of the traditional time inverse over current protection is analyzed, and then a new DG optimization strategy is proposed with its limitations pointed out. Based on the detailed analysis while focusing on the application of the fault current limiter (FCL) in the distribution network with its high impedance characteristics, a new and applicable protection scheme using FCL in the distribution network is put forward. It is then verified by actual simulation of Meizhou island energy storage power station in Fujian province with the PSCAD model. The protection method used in the distribution network can effectively reduce the impact of the inverter-based distributed generations on time inverse over current protection, coordinating the distribution network and traditional protection, and ensuring stable operation of the distribution network.