输电线路相差保护新原理  

A novel phase comparison protection principle for transmission lines

作　　者：张苏敏[1] 古斌[1] 曹良丰 朱烈锋[1] 

机构地区：[1]绍兴文理学院,浙江绍兴312000 [2]湖南省常德供电分公司,湖南常德415001

出　　处：《电力系统保护与控制》2015年第2期76-83,共8页Power System Protection and Control

摘　　要：相差纵联保护具有区别电力系统振荡与短路的优越性能,但传统相差保护在内部故障时灵敏度易受负荷电流和过渡电阻的影响,且应用于双回线或环网时其性能受线路分布电容影响,在外部故障时保护可能误动。基于无损线路分布参数模型及故障分量保护原理,提出了新型相差保护原理。理论上保护性能不受负荷电流和过渡电阻的影响,且完全杜绝了外部故障时保护误动的可能性,极大地提高了保护安全性,且各种内部故障时可靠动作。理论分析表明所提原理适用于各种故障类型,其性能不受故障电阻及系统运行状态等的影响。大量的仿真也证明了该原理的正确性。Phase comparison protection possesses the superior performance of distinguishing between power system oscillation and fault, but the sensitivity of conventional phase comparison protection during internal faults is susceptible to the influence of load current and the fault resistance, and its performance is significantly influenced by the distributed capacitance of ultra high voltage （UHV） transmission lines, which leads to the maloperation of phase comparison relay. A novel distributed parameters model based positive sequence superimposed components phase comparison protection principle is proposed. The protection performance of the novel principle is not affected by load current and the fault resistance theoretically. On the other hand, the novel principle completely overcomes the effects of distributed capacitance to protection, greatly improves the security of protection. The protection maloperation problem as the external fault of long distance UHV line occurs as well as the maloperation of non-faulty circuit as fault occurs in one of the double-circuit line on the same tower can be solved. Extensive simulations are performed to evaluate the performance of the proposed algorithm. The results show that the algorithm is reliable for UHV power transmission line protections. Also it is immune to fault resistances and system condition.

关 键 词：安全性 分布参数模型 双回输电线路 相差保护 故障分量网络 

分 类 号：TM773[电气工程—电力系统及自动化]