Inspection And Diagnosis Analysis Of Current Transformer In GIS Equipment

GIS substation has rapid development in recent years since the small footprint,excellent dust resistance,long maintenance cycle and other advantages.However GIS has closed apparatus.When testing the internal current transformer the primary circuit become long,primary resistance and inductance multiplied.Use of the existing traditional up-flow measuring differential principle technology when testing current transformer,Up-flow capacity,the volume and weight of up-flow devices have multiplied.Detection is difficult to complete all the rules of the current point,even unable to carry out verification work in some places where space is limited.Therefore,developing GIS Current Transformer site verification of new technologies is important.This paper studies the principles of GIS within the current transformer and its characteristics,unified and simplified circuit model and completed hardware circuit design according to the characteristics of each parameter.By applying different signals to measure the influence of the parameters of the current transformer error,and ultimately completed measuring of current transformer for GIS energy metering.The testing method use of different frequency small-signal based on the classical error theory of transformer,using iso-frequency small signal injection to measure parameter characteristic values which has effect on transformer error.Including 1.6 kHz signal measuring ratio and symmetry offset frequency signal measuring admittance two technical improvements.The test signal is digitized.The transformer characteristic parameters and error obtained according to classical theory of transformer errors after the Fourier transform and arithmetic.Development of GIS type CT calibrator,achieve without the use of a constant current source,standard CT,GIS can be detected formula CT.Solved the problems of traditional of testing way which heavy equipment,large capacity,primary wiring difficulties,detect problems and high cost indirect measurement device anti-interference ability,GIS formula can not be measured,the higher ratio and non-ratio CT issues.It developed a GIS Current Transformer testing equipment to achieve a field test equipment portable and miniaturization.GIS can be used in field testing within the conventional current transformers and current transformers.