一种基于柜式母线故障特性的中低压母线精准保护

为了快速切除柜式布置的中低压母线故障,针对开关柜密封结构故障的特点,结合运行方式,给出一种新型中低压快速母线精准保护。利用燃弧试验要求和实际运行故障的录波数据,研究发现柜式布置的设备两相故障最终都会发展为三相短路故障的特征。新保护只在三相故障时才启动,同时结合三相故障电流自动判断系统运行方式,做到保护和方式智能融合,综合判断决定跳母联开关策略,缩短隔离故障时间,同时利用母线三相电压闭锁,杜绝线路环网和远区故障的误动风险。新保护突破传统保护多重配合的弊端,能够高效快速切除母线故障,解决了当今电网的燃眉之急。安装简单,接线少,适合现场和产业化的需要,是继电保护的发展方向之一。

A kind of accurate protection of mid-low voltage bus based on the fault characteristics of cabinet bus

In order to quickly remove the mid-low voltage bus fault arranged in the cabinet, according to the characteristics of the switch cabinet sealing structure fault, combined with the operation mode, a new type of medium and low voltage fast bus precise protection is given. Based on the requirements of arcing test and the recording data of actual operation faults, it is found that the equipment faults arranged in cabinet will eventually develop into three-phase short-circuit faults. New protection only starts when the three-phase fault appears, at the same time judges system operation mode combined with three-phase fault current, achieves protection and the way intelligent integration and strategy which is chosen to jump bus coupler after comprehensive judgement, shortening the time of isolation fault. In the meanwhile using the three-phase voltage lockout, it puts an end to risks of false action of ring network and remote area. The new protection breaks through the disadvantages of the traditional multiple protection, and can efficiently and quickly remove the bus fault, thus solving the extremely urgency problem of today''s power grid. Simple installation, less wiring, and suitable for the needs of field and industrialization, is one of the development directions of relay protection. This work is supported by National Key Research and Development Program of China (No. 2017YFB0903201) and Science and Technology Project of China Southern Power Grid Co., Ltd. (No. GDKJXM20161906).