Design and Optimization of Field Mill Sensors for Accurate Measurement of HVdc Ground Electric Fields Based on Amplifier Parallel Optimization and Wavelet Decomposition Techniques

With the rapid development of high-voltage direct current (HVdc) transmission technology, the demand for monitoring the DC total electric field at ground level has increased significantly. The methods of the traditional electric field measurement are susceptible to noise interference, which affect the accuracy of measurement. This paper investigates the sources of noise interference in electric field measurements and proposes a signal processing method based on amplifier parallel optimisation of the signal conditioning circuit and Morlet wavelet decomposition. By improving the signal-to-noise ratio during the measurement of the device, the anti-interference capability and measurement accuracy of the field mill sensor are significantly enhanced. The experimental results show that the proposed signal processing methods of amplifier parallel optimisation signal conditioning circuit and Morlet wavelet decomposition can effectively eliminate the interfering signals during the measurement process, improve the signal-to-noise ratio of the measurement circuit, and retain the details and response speed of the signals, which improves the accuracy of the measurement of the ground electric field of the ultra-high-voltage direct current transmission.