High speed disconnect switch with piezoelectric actuator for medium voltage direct current grids

With the future adoption of intermittent sources of power generation and the need for dynamic and reconfigurable power systems, a shift in power system design leans towards power electronics based, fault current limited distribution systems. Design requirements for breakers will focus on fast operation to handle dynamic changes, rather than breaking large magnitude fault currents, as in conventional breakers. High-speed disconnect switches are expected to play a vital role in future DC shipboard power systems. Previous work on an NSF funded project resulted in the development of a 200 A, 15 kV fast mechanical disconnect switch for AC applications. This paper explores the use of the same type of technology for DC power systems, describes the differences and identifies the research and development work needed to make the technology fit for shipboard applications.