时谊,陈海龙,丘慧龙,沈燕华,刘志文,牛志雷.核电站辅助变压器缺相保护研究[J].电测与仪表,2018,55(11):125-129. Shi Yu,Chen Hailong,Qiu Huilong,Shen Yanhua,Liu Zhiwen,Niu Zhilei.Research on Open Phase Protection For Auxiliary Transformer[J].Electrical Measurement & Instrumentation,2018,55(11):125-129.
核电站辅助变压器缺相保护研究
Research on Open Phase Protection For Auxiliary Transformer
Open phase Detection is of prime concern in the nuclear industry. Events at several nuclear power plants have shown that the open phases on the HV side of a transformer may be difficult to detect by existing plant instrumentation and electrical protection schemes. If an open phase condition is not quickly detected and the transformer not isolated from the system, tripping of critical motor driven loads and loss of plant safety systems can occur. An open phase condition on heavily loaded to moderately loaded transformers can however be reliably detected and protected against with conventional protection relay schemes. Conversely, reliable open phase detection for all transformer connections which are lightly loaded or unloaded is challenging.This paper describes the issues from loss of a phase for nuclear power plants auxiliary transformers and proposes a new universal protection scheme applicable to most power transformer configurations. The new scheme uses optical CTs to reliably detect open phase from heavy loads to medium load transformers and reliably detect open phase from no load transformer.
