Circuit Breakers for Fault Current Interruption in HVDC Grids

Abstract:
Today, the interest in HVDC connections is growing throughout the world. First multi-terminal HVDC networks based on VSC technology have been built already and the need for HVDC circuit breakers with extremely fast reaction time is increasing. This contribution is introduced by an overview of factors that influence fault currents in HVDC networks and a comparison to frequently used test currents. In the following, the dimensioning of different circuit breaker topologies is explained using an example fault current. After comparing the interruption performance of selected topologies, the influence of changes in the fault current on the topology dependent interruption behavior is qualitatively discussed. A comparison with currently used test currents indicates, in which areas further investigation is needed.