Parallel diode‐clamped linear converter for withstand test and partial discharge measurement of electric equipment

Abstract

High-voltage withstand tests are essential for electric equipment like power transformers, electric cable lines, gas insulated switchgears etc. The partial discharge (PD) measurement for such equipment under applied high voltage is also required at the same time. Pulse Width Modulation (PWM)-based variable frequency power supply (VFPS) finds wide applications in the series resonance high-voltage testing circuits. However, the steep rising and falling voltage edges in the PWM process will produce large amount of partial discharge interference in a wide spectrum range, which will confuse the real partial discharge signal of the device and lead to the wrong estimation of the insulation status. This paper proposes a new VFPS based on the highefficiency linear power amplifier without PD interference. The topology and principle of the VFPS are given and discussed. A prototype rated at 232 V/35 A was designed and constructed to verify the feasibility of the proposed VFPS. Physical experiments were carried out on the prototype.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Design and implementation of a novel high-frequency current transformer for partial discharge measurements

“…High-voltage cables are widely used in city power supply, large-scale industrial and mining enterprises, railroad departments, and so on. Manufacturing process, workers' construction technology, aging, and other factors will lead to partial discharge phenomenon in cables, and when accumulated to a certain extent, insulation defects deteriorate, and even breakdown or burn phenomenon [1][2][3][4][5][6][7]. Partial discharge detection is an important method to determine the performance of cable insulation [8][9][10][11][12].…”