摘要
分析和比较了大型机组各种中性点接地方式,阐述了定子经电阻接地时电阻必须满足的条件,以上海吴泾第二电厂为实例进行了验证。根据基波零序电压定子接地保护和三次谐波定子接地保护原理,以GE公司的DGP保护为例具体分析。针对大型机组100%定子接地保护灵敏度差的问题进行了讨论,提出了采用GE公司的DGP保护解决方案。吴泾第二电厂实验表明,在负荷较大时该方案能明显提高定子接地保护的灵敏度。
Neutral point earthing manners of large-scale generators are analyzed in this paper. The qualifications that the resistance must satisfy are also illustrated and testified by Shanghai Wujing Power Plant No. 2. The paper expounds principles of fundamental zero-sequence voltage protection for stator grounding as well as third harmonic wave protection for stator grounding and analyses the case of DGP supplied by GE in detail. The problem of the poor sensitivity of 100% stator ground protection in large-scale generator is discussed and a solution is proposed. The test at Wujing Power Plant No. 2 indicates that this solution can enhance the sensitivity of stator ground protection obviously under heavy load condition.
出处
《水电能源科学》
2008年第2期167-170,共4页
Water Resources and Power
关键词
定子接地保护
中性点接地方式
三次谐波
基波零序电压
stator ground protection
neutral point earthing manners
third harmonic wave
fundamental zero-sequence voltage
