Development of a Three-Dimensional Optical Waveguide Sensor for Pulsed Electric Field Measurement

Non-contact electric field sensing technology is currently a solution for voltage measurement at critical nodes in power systems. This study focuses on the development of a small-sized, high-resolution, and wide frequency range three-dimensional(3D) pulsed electric field measurement technique. A three-dimensional integrated optical waveguide electric field sensor(OWEFS) based on the Mach-Zehnder interference effect is proposed. An asymmetric waveguide structure with two conical electrodes and one segmented electrode is introduced. A 3D electric field measurement probe is designed, and simulation studies and experimental verification are conducted to assess its measurement range, directionality, and temporal waveform measurement capabilities. The volume of this 3D probe is approximately 3 cmx I cm> 10 cm, which is about 10 times smaller than conventional probes, thus improving the spatial resolution of electric field measurements. After assembling the electric field measurement system, calibration of the proportionality coefficients for each direction in the three-dimensional coordinate system is performed. Experimental results demonstrate that the probe accurately captures the temporal waveform of the tested lightning-induced pulsed electric field and exhibits good directionality. Under lightning-induced pulsed voltage, the comprehensive measurement error of the sensor is less than 3%.