A simple method for fast routine testing and dynamic ratio error of current or potential transformer and its instrument

A novel method for the fast routine testing of the dynamic ratio error of a current or potential transformer (CT or PT) is presented. The operating principle and the adopted instrumentation are also discussed. Using a fast Fourier transform technique, the sampled signals in the time domain are converted to the frequency domain. Thus the ratio error and phase error of the CT or PT under test can be determined rapidly, and the ratio error of the dynamic response of the CT to applied harmonics can also be obtained. The effectiveness of this technique has been confirmed experimentally