Research and Implementation of an Improved Non-Contact Online Voltage Monitoring Method

High-precision non-contact online voltage monitoring has attracted considerable attention due to its improved safety. Based upon existing research works and validation of non-contact voltage measurement techniques, an enhanced approach for online voltage monitoring is proposed in this paper. By analyzing the relationship between distributed capacitance and coupling capacitance, a resistive–capacitive signal input circuit is designed to address scenarios involving large distributed capacitance in engineering applications. Furthermore, to improve measurement accuracy, a phase shift vibration method is introduced based on the investigation of the effect of relative phase shifts in mixed-frequency signals. The proposed circuit architecture and data processing method are simple in design and have been verified through experimental prototype, demonstrating stable long-term performance under room-temperature conditions.