7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

24 / 2024-03-28 08:16:44

The Influence of Conformal Mesh and Discrete Ordinates Radiation Model on the Simulation Accuracy of HVCB Short-Circuit Current

conformal mesh, discrete ordinates radiation model, HVCB, short-circuit current

Nowadays, computer simulation technology has been widely used in the research and development process of HVCB. In order to improve the accuracy of simulation, various mathematical models and simulation techniques have been proposed. The purpose of this paper is to verify the impact of conformal mesh (shared topology) and discrete ordinates (DO) radiation model on simulation accuracy, and the simulated pressure of the thermal expansion chamber is the comparison index in this article.



The main contents of this paper include:



(1) Due to the existence of moving parts in HVCB, most simulation methods divide the simplified model into movable and fixed parts, and the interfaces between them are only connected by non-conformal mesh. Even with some compensation algorithm, non-conformal mesh will still cause a loss in simulation accuracy, and this loss is accumulated as the parts move. In order to improve the simulation accuracy, this non-conformal method is replaced by the conformal/remeshing method. Specifically, the same nodes are used to connect the movable and fixed parts, and a remeshing operation is performed every 1mm distance for achieving relative movement.



(2) In past simulation techniques, exposure ratio was used to describe the portion of arc energy absorbed by the nozzles, which was considered low precision. Even if a certain part of the nozzle has not yet been exposed to the arc, this part of the nozzle has actually begun to absorb arc energy because proximity of the arc. Therefore, the exposure ratio is replaced by a discrete ordinates (DO) radiation model, which improves the accuracy of calculations regarding the energy absorbed by the nozzle.



(3) The updated simulation method was applied to 6 models and compared with past simulation techniques. The results showed that the simulation results of thermal expansion chamber pressure had a 10% to 20% improvement in accuracy.