Model-based Optimization of the Switching Performance of a Switch Disconnector

Low voltage switch disconnectors (SD) combine rated load switching with disconnector functionality, providing safe electrical isolation. Electrical contacts are separated forming an arc discharge that needs to be quenched at first current zero (CZ) protect the and SD itself. With increased line voltage, interruption CZ crossing is getting more difficult due transient recovery (TRV) larger post current, leading excessive contact erosion longer arcing time. Arc simulation methodology was utilized improve design for better cooling close CZ. Therefore, benchmark values of resistance thermal time constant were evaluated a successful test lower voltage. The efficiency different designs higher analyzed by 3D simulation. A revised able clear overload currents voltages CZ, preventing damage.