Modelling of hybrid DC circuit breaker based on phase-control thyristors

摘要

This paper presents model of hybrid direct current (DC) circuit breaker (CB) based on phase-control thyristors. The design aspects are shown and the CB parameters are calculated for a 120kV and 1.5kA DC CB assuming 10kA interrupting current. An internal control system for opening and closing is presented. The DC CB is modelled at system level in PSCAD. Simulations are used to evaluate the DC CB performance under different operating conditions such as opening and closing. The model represents well DC CB including main internal subsystems and can be employed for DC grid protection studies. It is also concluded that the thyristor-based hybrid DC CB potentially benefits in higher fault current interruption compared IGBT-based hybrid DC CB. However on the downside, simulations indicate that extinction time of phase-control thyristors results in DC CB longer opening time.