Phase-shift current to match voltage shift through delta-wye XFRMR

[sschindlbeck]

I am in need of a method and hardware to utilize the secondary of an existing CT circuit (wye connected) connected to the high side bus of a 12470/480V Delta/Wye transformer and have its phase and magnitude referenced to the low side. In other words, I need a thirty degree phase shifting auxiliary ct circuit that does not interfere with the existing mains ct circuit.

Does anyone have any experience in auxilliary CT circuits to accomplish this phase-shift. Metering equipment will not allow a phase-shift to the 480V voltage reference, so the shift needs to take place on the current. Please recommend what components you might have used and a configuration to accomplish this task.

 

[busbar]

Given “…auxiliary ct circuit that does not interfere with the existing mains ct circuit”… ‘Cutting in’ to existing-component wiring where currently used for another purpose may initially be logistically cumbersome and a headache to maintain.

Have you considered using a fully secondary-connected watthour meter with a programmable loss-compensation algorithm? {One would need to use data from the power-transformer production test report, but the procedure seems a well-documented and accepted method.}

Using auxiliary CTs in a phase-shifting [id est, wye/delta] arrangement where revenue transfer is involved may present special accuracy-class considerations; will always be difficult to test and likely unmanageable in securing against “modification,” particularly if any of the needed metering components are owned ‘by others.’