摘要
国内750 kV输变电示范工程已投入运行近两年.在国内对于750 kV设备尚无明确整定规程的情况下,结合现有的继电保护相关规程,探讨了750 kV示范工程线路保护配置和整定原则.针对750 kV超高压系统的有关特点,提出750 kV线路保护必须满足双重化要求,并且主保护应采用不同原理.同时,结合750 kV输变电示范工程实际,研究分析了差动保护有关定值的整定,并对750 kV线路距离和零序后备保护的灵敏度要求作了论述.最后,对零序电流保护最末段的抗过渡电阻能力的深入分析表明,该段设置为300 A时能够适应400 Ω过渡电阻.
Up to now,the 750 kV transmission pilot project in our country has safely operated for about two years.Without exact code to follow,this paper discusses the protection configuration and setting calculation for Guan-dong 750 kV line according to existing regulations.According to the characteristics of 750 kV super-high vottage networks,this paper points out that 750 kV line also needs duplicate protection with different theories.At the same time,the paper analyses the current-differential relay settings of Guan-dong 750 kV line based on its actual operation mode and the sensitivity requirement for backup protections.Finally,the paper analyses the capacity to detect high arc-resistance fault of the last stage zero-sequence overcurrent relay.
