摘要
在分析基于负序电压极化量的自适应接地距离继电器的基础上,为解决此类继电器在受电侧因高阻接地引起的同相区域不正确动作问题,引入一组可变圆限定性动作方程。该动作方程利用故障前补偿电压与故障后同相临界补偿电压之差始终与受端电压相互垂直的特性,将同相区域完全闭锁并最大限度地保持了原有耐过渡电阻能力,且方程本身不受同相区随系统功角变化而改变的影响。由此提出可变圆限定性负序电压极化距离继电器的修正判据,讨论了其阻抗动作特性。理论分析表明,采用此判据后,受电侧保护不会出现误动与拒动现象,具备较高的动作灵敏度及明确的方向性。EMTDC仿真实例验证了理论分析的正确性以及该继电器在线路保护中的有效性。
On the basis of analyzing adaptive earthing distance relay based on negative-sequence voltage polarization, to solve the malfunction of such kind of relay in same-phase region due to high resistance grounding at the receiving side a set of changeable circle restrictive operation equations are introduced in.Using the feature that the difference between the compensation voltage before the fault and post-fault critical compensation voltage in the same phase is perpendicular to the voltage at receiving end,the same-phase region is fully blocked by the operation equations and the original ability of withstanding transition resistance is kept to the hilt,and the equations themselves are not affected by the change of the same-phase region varying with system power angle.From this, a modified criterion for distance relay with changeable circle restrictive characteristics based on negative-sequence voltage polarization is proposed and its operation characteristic is discussed.Theoretical analysis shows that using the proposed criterion the malfunction and misoperation of protection relay at receiving side will not occur,and the protection relay possesses higher operation sensitivity and definite directionality.The correctness of theoretical analysis and effectiveness of such a relay in transmission line protection are verified by results of EMTDC simulation.
出处
《电网技术》
EI
CSCD
北大核心
2012年第11期240-246,共7页
Power System Technology
基金
广西教育厅科研基金资助项目(10593103004)
关键词
距离继电器
负序电压
可变圆特性
过渡电阻
线路保护
distance relay
negative-sequence voltage
changeable circle characteristic
transition resistance
transmission line protection
