Sensitivity analysis of Voltage Transformer compensation to the accuracy of the primary current transducer

A typical approach for the compensation of voltage transformers (VTs) is based on the generation of an auxiliary voltage that has to be added to the secondary electromotive force. The auxiliary voltage has to compensate the voltage drops due to the current flowing in the primary circuit. At this aim, the compensating circuit has to sense the primary current in the different working conditions. It is clear that the accuracy of the employed current transducer affects the compensation effectiveness, since it modifies the auxiliary voltage. In the paper an analysis of the sensitivity of the performances of VT compensation with respect to the variation of the current transducer accuracy is performed. The obtained results allow the selection of the proper current transducer that represents the suitable trade off between the transducer costs and the achievable accuracy class for the compensated VT.