Investigation on DC interruption based on artificial current zero of vacuum switch

Abstract

Direct current interruption utilizing vacuum switch based on artificial current zero is investigated. A high-speed vacuum switch, which is driven by electromagnetic repulsion force, is adopted as the main switch. The injection of high-frequency countercurrent is controlled by a triggered vacuum switch. The main experimental current is supplied by a LC circuit. The overvoltage generated during interruption is suppressed by metal oxide arrester. The interruption process is also simulated via a circuit model, with which the two important current commutation processes are analyzed, i.e., the current commutation from main switch to countercurrent branch, and the current commutation from countercurrent branch to arrester branch. Simulation results are compared with measured waveforms of voltage and current.