Electronic transformer protection
Electronic transformer protection
(OP)
Interested to know if anyone has experienced problems with modern electronic protection relays designed for power transformers. I have recently experienced failure to operate with a close in secondary earth fault on a recently commissioned 66/22kV power transformer. The device appears to have gone to sleep as the event log is competely clear of any events involving the fault. Subsequent primary and secondary tests indicate the relay is now operating perfectly. The manufacturer states no knowledge of problems to date. Leaves me nervous about the possibility of another failure. Reluctant to give manufacturer of relay.
Would appreciate comments
Would appreciate comments






RE: Electronic transformer protection
Have had multiple problems with two styles of harmonic-restrained transformer-differential relays, but they were false trips.
Hindsight suggestions are: 1.) Had the device been polled for seeming logical “meter data”? and 2.) Were “watchdog” alarm contacts monitored?
You may want to propose to the relay producer sending a new relay and use the packing materials to return the suspect device. Although not an ideal situation, they are likely most qualified to evaluate the device.
Check the IEEE PES-PSRC for Manufacturer’s Service Letter Database Project at http://www.pes-psrc.org/i/ServiceData.html or other materials at http://www.pes-psrc.org/Apublications.html
RE: Electronic transformer protection
RE: Electronic transformer protection
RE: Electronic transformer protection
RE: Electronic transformer protection