含DG的智能配电网快速自愈技术研究

Research on rapid self-healing technology of smart distribution network with DG

由于我国城镇配电网在建设之初并没有考虑到智能电网导致目前难以配置通信通道,且分布式电源接入配电网使传统的三段式过流保护难以适应拓扑的变化而失去判据。为解决这一问题,首先分析了正序分量控制策略下逆变型分布式电源的等值数学模型,然后结合对称分量法以相间短路为例分析了分布式电源对故障电流的影响。最后提出了一种适用于含分布式电源的配电线路的无通道保护快速自愈方案,按区域划分断路器分别进行整定,并结合涡流斥力真空高速开关使故障线路快速切除。该方案不依靠通信通道,节省了建设维护通信通道的成本,配电线路可在0.3 s内实现自愈,符合中压配电网继电保护整定原则的要求。通过PSCAD/EMTDC仿真验证了所提方法的正确性。

Since the urban distribution network in China did not consider the smart grid at the beginning of construction,it is difficult to configure the communication channel at present,and the access of distributed power supply into distribution network makes the traditional three-stage over-current protection difficult to adapt to the topology change and loses the criterion.In order to solve this problem,this paper firstly analyzes the equivalent mathematical model of the inverter-type distributed power supply under the positive sequence component control strategy,and then,analyzes the influence of the distributed power source on the fault current by using the symmetrical component method as an example.Finally,a non-channel protection rapid self-healing scheme suitable for distribution lines with distributed power supply is proposed.The circuit breakers are divided according to the area,and the fault line is quickly cut off by combining the eddy current repulsive vacuum high-speed switch.The solution does not rely on the communication channel,which saves the cost of constructing and maintaining the communication channel.The distribution line can achieve self-healing within 0.3 s,which meets the requirements of the relay protection setting principle of the medium voltage distribution network.The correctness of the proposed method is verified by PSCAD/EMTDC simulation.