Potential Transformer Accuracy at 60HZ Voltages Above and Below Rating and at Frequencies Above 60 HZ

Two standard, commercially available potential transformers designed for 60 Hz power applications are evaluated for use at frequencies of up to 10 kHz and voltages both above and below nominal rating. Using open and short-circuit impedance measurements, an equivalent circuit is developed that allows the calculation of the magnitude of the ratio correction factor (primary voltage divided by the product of turns ratio and secondary voltage) for frequencies up to 25 kHz for a wide range of burdens.