Modeling of calibration circuit for partial discharge measurement

Abstract

Most of the high voltage equipment suffers from failure due to internal faults. The type of fault caused due to insulation failure as a consequence of local electrical stress concentration in the insulation, whether gas, solid or liquid is very widely prevalent. This is called as partial discharge. So, partial discharge detection is highly important for an early detection of insulation failure. In this study, the simulation of partial discharge has been carried out with consideration of a cylindrical void inside an epoxy resin. The PD characteristic is studied by applying different high voltages across the insulation, which is necessary for designing of a calibration circuit. A calibration circuit has been modeled in SIMULINK for generation of PD pulses of known charge magnitude. The calibrator was connected across the test object and the pulses were detected via detector. A physical model of calibrator was made and output calibrating pulses were observed at Digital Storage Oscilloscope.