Application of Integrated Optical E-field Sensor for Non-Contact Transient Voltage Measurements

As power grids evolve towards smarter, more transparent systems, there is an increasing demand for highprecision, high-reliability, and cost-effective voltage measurement techniques. Unlike traditional contact methods, integrated optical E-field sensor offers safe, accurate voltage measurement without altering system topology. This paper established a non-contact voltage measurement system using integrated optical electric field sensors based on the Pockels effect. The system employed Common Path Interferometer (CPI) electric filed sensors, known for high stability and bandwidth, to measure transformer overvoltage caused by delayed closing and switching off in substations. Experiments show that the maximum delayed closing overvoltage occurs during the second closing action, while switching off overvoltage are lower and decay faster. This system provides a precise, reliable, and cost-effective solution for transient voltage measurement in modern power grids.