If possible, the compensation should be done in a way

that a single phase compensation VT is required only

If there is a step-up transformer between measuring VT and

circuit breaker, the connection group is usually Yd1 (+30 DEG)

or Yd11 (-30 DEG).

With the appropriate selection of the phases, the phase shift

can be compensated without any additional components. In

this example the compensation of the amplitude by factor √3

remains. This can be done by a single phase compensation VT.

In order to achieve higher accuracy, especially if higher load

(synchronizing instruments) is connected, the compensation

should be carried out on the generator side.

If a three-phase compensation is inevitable, 3 single-phase VTs

have to be selected which will then be connected according

to the needs. Be aware that the single phase ratio has to

be calculated.