FAULT CURRENT MANAGING BRANCH FOR SURGE-LESS CURRENT INTERRUPTION IN DC SYSTEM

摘要

Circuit breaker and fault current managing branch thereof, for power transmission using Direct Current (DC) applications, in particular for meshed DC grids, multi-terminal High Voltage Direct Current (HVDC) grids or HVDC lines, with a surge suppressor having DC bus terminal (1), transmission line terminal (2), and common terminal (3), comprising an auxiliary branch comprising a pre-chargeable capacitor (Ccb), wherein the capacitor is charged by the DC bus before the circuit breaker is closed for operation; and the capacitor is connected to be discharged to the transmission line when the circuit breaker is opened in operation, for suppressing the surge voltage across the circuit breaker. The auxiliary branch may comprise a charge sub- branch comprising a first controlled semiconductor switch (Tch) for closing the charge sub-branch and charging the capacitor by the DC bus before the circuit breaker is closed. The auxiliary branch may comprise a discharge sub-branch comprising a second controlled semiconductor switch (Tf) for closing the discharge sub-branch and discharging the capacitor to the transmission line when the circuit breaker is opened in operation.