基于直流断路器的多端柔性直流配电网智能化保护配置

Research on Intelligent Protection Configuration Based on DC Breakers for Multi-terminal Flexible DC Distribution Network

为提高多端柔性直流配电网的运行可靠性、缩短故障的影响时间,提出一种基于直流断路器的智能化保护配置方案。首先从拓扑结构、换流设备种类及运行方式等角度分析系统故障特征,随后划分保护区域,制定完整的保护原理、分层配置和直流线路故障选线方法。通过与一次设备及二次控制系统动作逻辑的协同配合,配置可适应于不同运行方式的具有动态定值自我切换、故障后系统快速恢复以及准确故障选线功能的保护方案。最后在PSCAD软件下搭建三端柔性直流配电网数字仿真模型并测试典型故障情况下的保护响应特性,验证了保护方案的有效性。

In order to improve the operation reliability of multi-terminal flexible DC distribution network and shorten the time of fault impact,an intelligent protection configuration scheme based on DC circuit breaker is proposed. Firstly,the typical fault characteristics of system are analyzed from the aspects of topology,converter and load types. Subsequently,after the protection area has been divided,the complete protection principle,the layered configuration and the DC line fault line selection method is developed. By cooperating with the operation logic of primary equipment and secondary control system,a protection scheme with self-switching dynamic settings,quick system recovery after fault,and accurate fault line selection is configured,which can be adapted to different operation modes. Finally,a digital simulation model of threeterminal flexible DC distribution network is built in PSCAD software and the protection response characteristics under typical failures are tested,which verifies the effectiveness of the proposed protection scheme.