Transformer having improved voltage and phase characteristics

Abstract

A coupling capacitor voltage transformer or potential transformer has its secondary winding tapped to provide a predetermined voltage across a portion of the secondary winding. The transformer is improved by an inductive reactance added in series with the secondary tap. The magnitude of the added inductive reactance is selected so that the sum of the added reactance and the leakage reactance between the transformer primary winding and the portion of the secondary winding referred to the primary is equal to the leakage reactance between the primary winding and the full secondary winding referred to the primary. Under this equality condition, the phase relation between the primary and secondary voltages will be the same for a standard type burden or equivalent burdens connected either across the portion of the secondary winding or across the full secondary winding. The added inductive reactance may also be used with a separate secondary winding having a lower referred leakage reactance to provide a phase relation for that secondary winding that is the same as the phase relation for the secondary winding having a higher referred leakage reactance.

Dependencies are inferred from the claim text.