Very fast transient overvoltage monitoring of GIS equipment based on non-contact voltage sensors

The operating voltage and frequency of GIS equipment are high, and the speed of voltage change is very fast. Monitoring methods are required to have the ability to respond quickly. This article studies a fast VFTO non-contact monitoring method for GIS equipment based on inductively coupled voltage sensors. Based on the principle of transient overvoltage generation, we select an inductive sensor with better anti-interference performance to collect transient overvoltage signals. We use the wavelet transform method to filter and process the collected signals, removing noise and unnecessary frequency components, preserving the signal within the target frequency range, and improving signal stability. Based on the signal filtering results, the FFT method is used to extract the waveform of transient overvoltage signals, obtain the relevant characteristic parameters of transient overvoltage, and accurately capture the transient overvoltage events suffered by ultra-high voltage GIS equipment. The experimental results indicate that the proposed method is an effective and promising solution that can provide more reliable voltage monitoring and protection for ultra-high voltage transmission systems.