Development of automatic integrative tester forelectric power protection CT

Basic functions,principle of automatic test,main hardware structure and software flowcharts of an automatic integrative tester for electric power protection CT(Current Transformer)are discussed.The tester can automatically test the transformation ratio-polarity of the protection CT,secondary load,10 % error curve,volt-ampere characteristic curve and so on,real-timely display the test procedures and data result,and print the test data and characteristic curves at site.All parts are integrated in one portable casing.It can use the automatic voltage-regulation sine AC power supply controlled by internal motor,or an external booster to enlarge the test range.A rotating mouse instead of keyboard makes operation easy.Chinese characters are shown on a 320 × 240 LCD(Liquid Crystal Display),and the interface is friendly.Digital technology and high pre-cision sensor technology ensure the test accuracy and efficiency.