无刷励磁机两点接地对DNC检测的影响研究  

The Influence Study for Non-Conduction Detection when the Exciter is Grounded at Two Points

作　　者：沈红 段琰璞 向超 SHEN Hong;DUAN Yanpu;XIANG Chao(State Nuclear Power Demonstration Plant Co.,Ltd.,Rongcheng of Shandong Prov.264300,China;China Nuclear Power Engineering Co.,Ltd.Shenzhen of Guangdong Prov.518124,China)

机构地区：[1]国核示范电站有限责任公司,山东荣成264300 [2]中广核工程有限公司,广东深圳518124

出　　处：《核科学与工程》2023年第1期79-84,共6页Nuclear Science and Engineering

摘　　要：无刷励磁机DNC(Non-Conduction Detection)装置通过检测励磁机旋转电枢出线上的脉冲电流的方法检测旋转二极管不导通故障。当检测到断一相故障时发出报警信号,断两相故障时发出跳机信号。某核电站机组功率运行期间经受一个瞬态后,DNC装置先发出断一相故障报警信号,几秒后又发出断两相故障跳机信号,造成机组跳机。经停机后检查,励磁机未发生断两相故障,仅断一相,但磁极存在接地故障。本文通过分析无刷励磁机励磁绕组两点接地对DNC装置检测的影响,解释了DNC装置误发断两相故障跳机信号的原因。The non-conduction detection device of the brushless exciter detects the non conduction fault of the rotating diode by detecting the pulse current on the outgoing line of the rotating armature of the exciter.When one phase failure is detected,an alarm signal is sent;and when two-phase failure is detected,a trip signal is sent.After the unit of a nuclear power plant experienced a transient during power operation,the DNC device first sent out a phase failure alarm signal,and then sent out a phase failure trip signal a few seconds later,resulting in unit trip.Through inspection after shutdown,the exciter did not break two phases,only one phase,but the magnetic pole had grounding fault.By analyzing the influence of two-point grounding of excitation winding of the brushless exciter on the detection of DNC device,this paper explains the reason why DNC device mistakenly sends out two-phase fault tripping signal.

关 键 词：无刷励磁机 磁极接地 DNC 

分 类 号：TL48[核科学技术—核技术及应用]