Ultra Fast DC Switch

Abstract

With advancements in power electronics, DC power systems are a strong contender forfuture power system and shipboard application studies. However, to ensure proper DC power systems, protection engineers must develop different DC protection schemes to maintain proper system protection levels. The critical issue behind developing DC protection devices is that the signal never crosses zero naturally, as in AC circuit breakers and AC disconnect switches. There is also a necessity for galvanic isolation in the DC protection system. A method developed is pairing a mechanical commercial-off-the-shelf vacuum interrupter, a Thomson coil actuator, and a current commutating drive circuit (CCDC). The Thomson coil offers fast repulsion capabilities to separate the interrupter. Next, the vacuum interrupter produces strong galvanic isolation and is rated for high current arcs. Finally, the CCDC extinguishes the arc by injecting a counter-current from a precharge capacitor and commuting the fault current into a separate semiconductor branch via coupled inductors. The Virtual Prototyping Process and Particle Swarm Optimization is implemented based on input parameters such as voltage and current and optimizes component-level values based on system-level requirements. After the optimization, the physical sizing of switch packaging can be optimized and sizes for the higer-level DC power system.