Fast Mechanical Disconnect Switch for Medium Voltage Distribution Systems

T. Damle, C. Xu, L. Graber, J. Goldman, M. Bosworth, M. Steurer
Florida State University, Florida, United States

Keywords: disconnect switch, power and energy systems, fault isolation

Integrated power electronics based medium voltage dc (MVDC) power and energy systems (IPES) are proposed by the Navy as the electrical distribution system for the next generation of surface combatants. IPES supports the ever increasing demand on electrical power by advanced mission loads such as directed energy weapon systems and other emerging electrically powered mission loads. In order to meet the required quality of power delivery service MVDC systems must support rapid fault clearing and system reconfiguration. A key enabling technology to achieve these goals is a fast mechanical disconnect switch. The specific disconnect switch technology proposed herein uses an amplified piezoelectric actuator integrated inside a vacuum switching chamber. The current prototype is rated for 600 A at 12 kVdc with an opening time of less than 1 ms. This disconnect uses innovative techniques in heat management and contact design to maximize current rating and voltage withstand. This technology can also be used within hybrid solid-state circuit breakers or fault current limiters in support of ac or dc DoD microgrid applications to increase fault tolerance and hence the availability of the electric power system to serve mission critical loads