This paper presents a design methodology of modular medium-voltage direct current (MVDC) solid-state circuit breakers (SSCBs) based on scalable power electronics building block (PEBB) units. A 1.33kV/40A PEBB prototype is successfully implemented, which is experimentally validated by 40A/1hour continuous conduction test and 1.33kV/200A fault interruption test. A 1.33kV/400A power disk prototype is then implemented based on 10 paralleled PEBBs and symmetrical busbar connections. A 400A/1hour continuous dc conduction test is conducted to verify its state-of-the-art 99.98% steady state efficiency, which paves the way for the next generation of high efficiency ultrafast solid-state breakers for MVDC systems.
