Surface Electric Field Measurement of Composite Insulator Using an Optical Waveguide Sensor

In this article, an integrated optical waveguide sensor is designed and developed to comprehensively analyze the surface electric field distribution characteristics of composite insulators. Based on the optical waveguide electric field sensor, an experimental system is set up for measuring the axial and radial electric fields along the surface of composite insulators under normal, damaged, and internally defective conditions. The experimental results show that when a 10kV power frequency voltage is connected, the radial and axial electric fields at the low and high voltage (HV) ends of the normal insulator are 21.53, 53.07 kV/m and 47.55, 105.12 kV/m, respectively. When the insulator surface is damaged, the radial and axial electric field intensities at the damaged locations increase by 37.59%–204.85% and 12.89%–32.69%, respectively. When an internal defect occurred, the radial and axial electric fields along the defect area increase by 18% and decrease by 127.72%, respectively. The radial electric field is more affected by the defect. The comparison with the calculation results shows that the integrated optical waveguide electric field sensor has great potential capability to be used for measuring the surface electric field of insulators.