E2c: Developing a fast DC breaker

Abstract: Good concepts for DC circuit-breakers have been searched throughout the whole history of electrical power systems. Visions for wide-spread transmission of electrical power, nation-wide or even covering continents, would benefit from HVDC transmission technology. This technology allows connections over long distances with low losses, small requirements for right-of-way and freedom to use overhead lines or cables of any length. Such transmission systems will support the use of green power, which is not always available nearby the load. Fast-acting circuit-breakers, available at reasonable costs, are severely needed for this vision to come true. We will talk about DC circuit-breakers in general, and in particular about development of a certain concept for fast DC interruption, which we are working on at SCiBreak. This concept integrates power electronics with an extremely fast-acting mechanical actuator operating on a Vacuum Interrupter. Cost aspects are most important, and we are exploiting a new principle that allows a significant reduction of the required amount of semiconductor devices as compared with other approaches. Testing of a laboratory prototype rated for 40 kV and 10 kA with operating time in the range of a few milliseconds is on-going and we will present some results from these efforts.   Bios: Lennart Ängquist: MSc from LTH 1968, PhD from KTH 2002. Worked with ASEA/ABB 1968-2008 with development of power electronics for industrial and traction motor drives and for power transmission applications. He was Adjunct Professor at KTH 2004-2010. One of the founders of SCiBreak AB 2014. Antoine Baudoin: MSc from Ecole Polytechnique, France 2007 and from KTH 2008, PhD from Uppsala University 2016. He is with SCiBreak AB since 2017 working with development of fast actuators for vacuum interrupter.