基于限流电抗器电压特性的直流线路保护研究

Research on DC Line Protection Based on Voltage Characteristics of Current-limiting Reactor

高压直流配电网保护是柔性直流配电网亟待解决的关键问题之一。基于限流电抗器的电压特性设计了一种新型的多端柔性直流线路保护方法。计及线路边界特性,提出了故障快速、可靠识别的方法,利用直流电抗器电压变化判据实现了保护的方向性。搭建了复合式环状结构的高压直流配电网模型,验证了所提方法能够满足直流配电系统保护速动性、可靠性和选择性的要求。

DC distribution network protection is one of the key issues to be solved urgently in flexible DC distribution net works.Based on the voltage characteristics of current-limiting reactors,a new multi-terminal flexible DC line protection method is designed.Use the line boundary c haracteristics for fast and reliable fault identification.And the DC reactor voltage change cri terion is used to achieve the directionality of protection.Finally,a DC grid model with composite ring structure is constructed on the RT-lab simulation platform,and this method can meet the fast-acting,reliable and selectivity requirements of DC distribution systems for protection.