Experience with 550 kV current transformers

At Manitoba Hydro the first 550 kV current transformers were placed in service in 1980 followed by additional units in 1994 and 2014. A total of three different designs are now in service. In-service failures or troubles occurred in 1986, 2004 and 2014. The paper summarizes what has been learned from the investigations.

[1]  M. Duval,et al.  Dielectric Behavior and Stabilization of Insulation Oils in EHV Current Transformers , 1985, IEEE Transactions on Electrical Insulation.

[2]  W. McDermid,et al.  Experience with 15-500 kV instrument transformers and bushings , 2009, 2009 IEEE Electrical Insulation Conference.