Time-continuous Kerr electro-optic field mapping measurement under impulse voltage using array photodetector

Abstract

Space charge affects the electric field distribution in high voltage-stressed liquid dielectrics and can cause insulation degradation. This letter reports on research using a Kerr electro-optic measurement system with an array photodetector for Kerr electro-optic field mapping measurements in propylene carbonate under application of switching impulse voltages to investigate the electric field and space charge effects in high voltage-stressed liquid dielectrics. The electric field distribution between parallel aluminum electrodes is measured, and the results are compared with those measured using a charge-coupled device measurement system. The array photodetector measurement system has the advantages of higher sensitivity and higher time resolution because simultaneous optical Kerr measurements can be taken at multiple positions using a multi-element array photodetector. The results show that bipolar homo-charge injection occurs between the parallel aluminum electrodes. In the near future, this measurement system will be used in continuing research into the measurement of space charge effects using low Kerr constant liquids such as transformer oil.