Multi-Physical Coupling Field Study of 500 kV GIL: Simulation, Characteristics, and Analysis

Abstract

With the construction of a large number of hydropower stations, transmission lines crossing a river and urban utility tunnels, gas insulated transmission line (GIL) has been applied widely due to its large transmission capacity, low environmental impact and high reliability. Accurate modelling of physical quantities and their characteristics of GIL provides a theoretical basis for its design and operation, which is of great significance to ensure the safety and reliability of GIL operation. The mathematical model and their relationship of GIL multi-physical fields are analyzed at first, upon which simulation model of GIL is built. Secondly, multi-physical coupling field model of electric, magnetic, thermal, fluid and stress field for GIL is studied, while simulation results are basically in consistent with experimental data to verify effectiveness of the model. Thirdly, distribution of multi-physical fields and their relationship are simulated and analyzed, while proximity effect, edge effect and compression factor of GIL multi-physical field are discussed. The results show that the radial temperature inside GIL is higher at the top, lower at the bottom, leading to uneven distribution of thermal expansion displacement, while the axial temperature distribution is basically uniform, which falls firstly and then rises near basin insulator thus results in edge effect. Proximity effect leads to asymmetric distribution and a slight increase of temperature inside GIL as well as a dramatic increase of air velocity around GIL. In addition, when ambient temperature is lower than-5 ℃, the compression factor is much lower than 1 and the effect of compression factor should be considered in simulation. INDEX TERMS GIL, multi-physical coupling field, finite element method, multi-physical characteristics. I.

Research on Steady‐State Thermal Behavior ofSF6/N2andCF3I/N2Mixtures in High Voltage Gas‐Insulated Lines (GIL)

“…Considering the magneto-hydro-thermal characteristics studied in the presented study, the steady state behavior can be modeled using the coupling form of Maxwell and Navier-Stoke (N-S) equation. The control equations are shown below [30,31].…”

“…[28], the authors studied the thermoelectric performance of the iTED element using fluid-thermoelectric coupled field numerical methods. In addition, research on alternative gases was presented in [29,30]. However, most of the presented reports did not consider the internal gas flow in the GIL and were only combining electromagnetic field and thermal field.…”

Influence of Conducting Particle on DC Flashover Characteristics and Tracking Property of GIS/GIL Insulator

“…Solid insulators are widely applied in gas-insulated apparatus including gas insulated switchgear (GIS) and gas insulated transmission lines (GIL) functioning as the main supporting and isolating components with insulating property [1], [2]. Then, gas/solid interface will form in the system due to the appearance of solid insulator.…”

Research on the Calculation Method of Equivalent Parameters of the Core Wire for the High-Voltage GIL Metal Shell Grounded Through the Copper Bar

“…At present, both the GIL comprehensive pipe gallery project in Sutong, China (Gong et al, 2019;Ning et al, 2020) and the underground comprehensive pipe gallery GIL project in Jiangxia District, Wuhan, China, have adopted the GIL metal shells that are grounded through a copper bar (Cheng et al, 2019;Niu et al, 2020). The voltage and current of the core wire will be affected by the coupling among the metal shell, the copper bar, and the core wire (Jun-qi, 2020).…”