CALIBRATION METHOD OF AMOUNT OF PARTIAL DISCHARGING CHARGE IN PARTIAL DISCHARGE MEASUREMENT

摘要

PURPOSE: To obtain a method for calibrating the amount of partial discharging charge which can measure the amount of partial discharging charge accurately when a partial discharge occurs in a power cable. ;CONSTITUTION: A detection impedance 4 is connected to both sides which sandwich an intermediate insulating connection part 2 of a power cable 1 and a charge for calibration is injected from both sides of the intermediate insulating connection part 2 of the power cable 1 via capacitances Cp₁ or Cp₂ and C_h. At that time, the values of partial capacitances Cp₁ and Cp₂ which are already known out of the capacitances Cp₁. Cp₂, and C_h are switched and a voltage across both terminals of the detection impedance 4 is measured in each case. Then, the value of the capacitance C_h which cannot be grasped is calculated based on the voltage across both terminals of the detection impedance 4 which was measured and the amount of injected calibration charge is obtained based on the calculated capacitance. Also, the ratio of Cp₁ and Cp₂ to C_h is set to 0.05 or less to determine whether the partial discharge is caused by pincushion defect or void defect.;COPYRIGHT: (C)1993,JPO&Japio