A WIDE RATIO ERROR POTENTIAL TRANSFORMER WHICH HAVE SAME VALUES IN NOMINAL amp; THEORETICAL RATIOS, AND EVALUATION METHOD OF THE PT RATIO ERROR MEASURING DEVICE

摘要

An accuracy measuring apparatus for a PT(Potential Transformer) ratio error measuring device is provided to accurately obtain a ratio error of the PT by compensating for a measured result using a compensation value of the PT for an overall ratio error. An accuracy measuring apparatus for a PT ratio error measuring device supplies same voltages to primary portions of a reference PT(40) and a PT to be measured(50), respectively. A ratio error measuring device(60) measures voltages at secondary portions of the two PTs, and the measured voltages are compared with each other. A WRE PT(Wide Ratio Error Potential Transformer) having nominal ratio error values matched with theoretical ratio error value is used in the PT to be measured side. A winding number of the primary portion of the WRE PT is maintained to be constant. The winding number of the secondary side is varied according to a ratio error adjusting unit.