Calculation Analysis of 5% Error Test Data for Protective Current Transformer
Ru Liu · 2015
Make a 5%error filed test for a unit of protective current transformer in a wind farm.The test data included the load impedance and the accuracy limit coefficient,etc.Based on three different checking criteria in DL/T 886-2004 The guide for selection and calculation of current transtormers and voltage transtormers,including general choice checking,rated limiting secondary e.m.f.checking,and the accuracy limit coefficient checking,with which calculating the secondary measurement value as short-circuit fault occured on the main transformer high voltage side.The measurement result showed that the current transformer met the requirement of 5%error,which could guarantee the secondary current value correct and effective,and avoid the maloperation and refuse operation resulted from the overlarge current value.