Synchronization through a YNd11 Xformer

[hmurayam]

We need to sync to the 345kV grid a Steam Turbine generator and would appreciate some help. We do not have a generator breaker and the idea is to sync using the 345kV switchyard breaker. Our generator is 23kV rated and we have a YNd11 345/23kV step up Xformer. Since we have 30 deg phase shift between HS and LS of the Xformer we plan to use at delta side Vab for sync reference and at the switchyard Vcn. This way we would not need a auxiliary PT to accomplish the phase shift. Does anybody faced the similar situation before??

 

[jbartos]

Suggestion: A single particular phase PTs might be applied and used. Also, there are being developed and applied various devices for synchronization of different equipment at the power distribution systems based on GPS (New York City Con Edison).

 

[davidbeach]

Many modern (microprocessor based) synchronizing devices can be programmed to sync across a fixed phase shift.

 

[digitrex]

Don't you have another PT at feeder side of 345kV CB? If you have this PT, the synchronizer will have a direct comparison between 345kV's busbar voltage and feeder voltage from YNdn11 transfromer.

 

[busbar]

Because of the potential for loss and delays from a simple mistake, it may pay to check and recheck VTs, components, wiring and synchronizing-relay calculations, settings and tests. Seasoned commissioning personnel should readily accept a degree of birdogging/oversight/rubbernecking inherent with “shared” accomplishment/responsibility/blame.