摘要
自并励励磁系统误强励使发电机电压和转子电流形成正反馈关系,当发电机过电压保护按照1.3 g、0.3 s^0.5 s设定时,实际发电机跳闸时,定子电压和转子电流已上升至更高值,此时,跳闸灭磁时常出现灭磁失败甚至烧毁磁场断路器。为此,本文提出在大型发电机继电保护中增设发电机空载过电压保护,可有效防止因励磁系统误强励导致励磁、发电机等设备损坏。
If self-shunt excitation system is fault forcing excitation, it can form a positive feedback relationship between the generator voltage and rotor current. When the overvoltage protection for generator is set in accordance with the 1.3 Ug,0.3s^0.5s, the stator voltage and rotor current have risen to a higher value at the actual generator tripping. Trip demagnetization failure or even burning on field circuit breaker often appear if trip demagnetization is carried out under the high voltage. This paper proposes that the no-load over-voltage protection shall be installed in large generator relay protection system to effectively prevent the excitation and generator damage due to faulty forced excitation.
出处
《水电站机电技术》
2015年第6期11-13,32,共4页
Mechanical & Electrical Technique of Hydropower Station
关键词
自并励励磁
误强励
空载过电压保护
Self-shunt excitation
Faulty forced excitation
No-load over-voltage protection
