Shape Optimization of High Voltage Electrodes
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Electric power engineering (MPEPO), MSc
Publicerad
2024
Författare
Shema, Junior
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Abstract
Electrostatic screens and electrodes used in high voltage apparatuses and in test setups in high voltage laboratories are essential for proper operation of the equipment and for performing high voltage withstand tests. Electrostatic fields generated on their surfaces must be minimized to prevent parasitic discharges in surrounding air especially under conditions of limited space. To realize this, shape of the electrodes can be optimized in a way that the maximum electric field strength is kept below the critical level corresponding to the initiation of breakdown in air. In the thesis, the optimization methods provided in COMSOL Multiphysics software were examined and shape optimization was employed in the electrostatic problem for minimizing the maximum field strength. Several 2D study cases reflecting typical electrode shapes providing different field enhancement factors were implemented. The effects of various parameters in the optimization algorithms on the shapes of the electrodes and respective reductions of the maximum field were analyzed. The influence of the proximity of the boundaries to the energized electrodes was also investigated and best practices for selecting numerical parameters for the optimization were established. Furthermore, 3D scanning of the real 400 kV high voltage divider equipped with a toroidal electrostatic screen was performed using Scaniverse software installed on iPhone. The obtained scan was cleaned up and imported into COMSOL Multiphysics for conducting electrostatic field calculations. The procedure developed with the 2D study cases was used for shape optimization of the 3D high voltage divider to demonstrate the validity of the method for real scale high voltage devices.
Beskrivning
Ämne/nyckelord
high voltage electrodes , Electrostatic screens