Research on influence factors of corona onset characteristics of AC grading rings based on three‐dimensional calculation physical model

Abstract

In order to obtain the influence laws and mechanisms of size parameters (ring diameter and pipe diameter) of the grading ring and environmental parameters (atmospheric pressure, temperature, and humidity) on corona onset characteristics of a grading ring, a threedimensional (3-D) calculation physical model of corona onset considering the influence of size parameters of the grading ring and environmental parameters is established by proposing an area factor of a photon absorption function suitable for the grading ring. Combined with the thickness of ionised layer and the effective ionisation coefficient, the influence mechanisms of size parameters of the grading ring and environmental parameters on corona onset characteristics are given. The calculation results show that with the increase of the pipe diameter and ring diameter, the corona onset voltage increases gradually and the corona onset field intensity decreases gradually. The increase of the effective ionisation coefficient leads to the expansion of ionisation region, which leads to the decrease of corona onset voltage with the decrease of atmospheric pressure and the increase of temperature. The enhancement of capacity for collisional ionisation in the region with the high field intensity leads to the decrease of corona onset voltage with the increase of humidity.

A physical model for the calculation of the corona onset voltage gradient of AC spacers

“…However, due to different photon area factors (PAFs) of electrode structures with different shapes, no physical model used to calculate the COG applicable to spacers, grading rings, and other electrodes with irregular structures has been proposed. Recently, our research group proposed a PAF suitable for grading rings and established the physical model for the calculation of the COG suitable for grading rings [18,19]. However, because the structure of the spacer is more complex and irregular, herein we focus on the physical model for calculating the COG of AC spacers.…”

Nonlinear Dynamic Characteristics of Automotive Gear Transmission System Based on Pure Torsion Model

“…The research on the dynamic characteristics of gear transmission system has always been one of the topics concerned and interested by many scholars at home and abroad, and it has also become an important topic. This technology has been deeply explored abroad [5][6]. Some European and American countries attach great importance to this new technology.…”