Interlaboratory Comparison of EHV Shunt Reactor Loss Measurements

A comparison of loss measurements on a 0.002 power factor, 110 MVA, 735 kV shunt reactor at the Hydro-Quebec Institute of Research using four different bridges from three independent laboratories, is described. The special features of the bridges, which were all basically of the three-winding transformer (current comparator) type, are discussed and their estimated uncertainties are given. In the region where all bridges were judged to be operable, the measured values lie within ±3% of the mean. For the two bridges which were specifically adapted for shunt reactor loss measurements, the measured values are within ±1% of the mean. The test conditions, results, and some of the problems encountered are discussed and recommendations for future comparisons are made.