Development of ultrahigh‐voltage standard voltage transformer based on series voltage transformer structure

Abstract

An ultrahigh‐voltage standard voltage transformer (VT) based on series voltage transformer (SVT) structure is described. A precise isolation VT is designed to realise the connection between the VTs of an SVT. Moreover, the ratio and errors of the SVT are discussed and calculated to reduce the magnetic error of the isolation VT, and capacitor compensation is proposed. Two calibration methods for the SVT are compared. The results are very approaching, and the largest differences between the two methods are <0.08 × 10 −4 and 0.08 min. The results indicate that the errors of an SVT can be obtained by testing at only half the voltage of the SVT.