Lightning impulse electric field measurement in long air gap based on the integrated electro-optical measurement system

The electric field is crucial to the research on the characteristics of long air gap discharge, which is of great importance to the development of ultra high voltage (UHV) projects. The measuring of electric field is one of the hot spots and makes great sense while doing the research. In this paper, an electric field measurement system based on the integrated electro-optical technology was proposed and calibrated between parallel plane electrodes, by which the input-output characteristic and measurement range of the system were obtained. Using this measurement system, the axial electric field was measured in 1m rod(different radii of curvature)-plane gap energized by positive lightning impulse voltage. Furthermore, the Laplace fields on the measuring points were calculated by charge simulation method (CSM). Comparing the measurement and calculation results, it was found that they agree very well and the maximum error is less than 5%. It is proved that this electric field measurement system is feasible for quantitative measurement of electric field of long air gap discharge.