Verifying method for ratio error and angle error of high-voltage potential transformer is proposed in this paper, on the basis of traditional measuring methods and the classic formula of potential transformer error, its measuring theory is also researched. Effective computational mathematics model is established to measure leakage reactance. Hardware and software design of potential transformer measuring instrument are given as well. The accuracy of measurement is improved and can meet the requirement of verification regulation. The practical application shows that the measuring instrument has wonderful accuracy and stability.
