The Resonant Optimization and Inverse Analysis of Vibration Capacitance Electrostatic Probe

The phenomenon of charge accumulation poses a significant threat to the electrical and aerospace industries. The accurate measurement and inverse analysis of surface charge has been a topic of great interest among scholars. To enhance the performance of electrostatic sensors, this article proposes a mechanical vibration structure with a double resonator resonance driving method. A new vibration structure has been designed and its vibration stability is analyzed based on modal analysis. According to test results, using the new driving mode and vibration plate can significantly improve the stability and accuracy of the sensor, and the measurement error is better than 0.5%. The simulation analysis shows that intervention of the probe leads to the accumulation of surface charge, which is intensified with decreasing probe distance. An inverse calculation method based on the charge of the annular region has been proposed, which can be used to calculate the initial potential before probe intervention.

I. Introduction

The ultrahigh-voltage direct current (UHVdc) transmission technology has the advantages of being suitable for long-distance transmission, large power transmission capacity, and easy to manage and regulate. The dry-type value-side bushing, as a crucial component, performs important functions such as mechanical support and current carrying [1]. The flashover on the surface is a common type of fault during dry bushing operation. The accumulation of charge can easily distort the electric field on the surface of the insulation material, resulting in a reduction of the flashover voltage along the surface at the weak point of the insulation at the gas-solid interface [2], [3]. It poses a significant threat to the stability and safety of the power system. Ma et al. [4] and Xue et al. [5] used a series of sensors to carry out the surface charge distribution on basin insulators and column insulators. However, considering that the multilayer structure of dry-type value-side bushing consisting of epoxy rubber-impregnated paper generates a strong vertical electric field component [6], it leads to a more complex charge distribution on its surface than that of basin insulator and post insulator. Optimizing the high accuracy and miniaturization of surface charge sensors is the priority to accurately grasp the surface charge distribution of dry bushing. It is of great significance to further grasp the surface flashover voltage characteristics of dry bushing and optimize its insulation structure design.