Test specialist Megger is using Coulomb, a tool from Canadian firm Integrated Engineering Software, to model a 40kV two channel discharge switch.
The tool is a 3D 'boundary element method' (BEM) electric field solver.
"In these types of switches, accurate estimation of electric fields is crucial," said Integrated. "To model such problems, the voltage on the electrodes is specified, whereas the metallic parts embedded within the dielectric materials will float to a voltage which Coulomb will determine."
BEM evaluates field problems by solving an equivalent source problem.
In the case of electric fields, it solves for equivalent charge, while in the case of magnetic fields, it solves for equivalent currents. It also uses an integral formulation of Maxwell's Equations.
"Unlike finite element analysis, the electric and magnetic fields are computed directly from the source," claimed Integrated. "This technique produces accuracies not attainable by finite element method.
The switch are rated at 40kV from 0 -1,500m altitude, -20 to +50°C, and up to 90% humidity. Each channel handles 2kJ under normal operation and 6kJ for emergency operation.
