Wide-Frequency Range Voltage Monitoring Device for Current Transformer

Abstract

To optimize the online voltage monitoring technology of the power grid and realize real-time fault warning for the power grid and capacitive devices such as current transformers (CT), this paper proposes a wide-frequency range voltage monitoring method based on current transformers according to the idea of measuring the leakage current of capacitive devices to restore the line voltage. The method measures the current transformer leakage current to invert the bus voltage and uses a wide frequency range current sensor to meet the measurement of high-frequency waveforms. This paper designs a CT wide-frequency range voltage monitoring device based on this method and conducts field tests of the device’s measurement effects. Through the fault monitoring test and voltage monitoring test, it is verified that the monitoring device is fully functional and can achieve accurate monitoring of harmonics, end shield current, relative dielectric loss, high-frequency partial discharge, and bus-voltage with high amplitude and high frequency, which can provide support for fault analysis and insulation design improvement and is of great significance to ensure safe and stable operation of the power grid.