System Inductance for MVDC Circuit Breakers

One option for implementing circuit protection in Medium Voltage Direct Current (MVDC) naval power systems is to employ Solid-State Circuit Breakers (SSCB) in a manner similar to the employment of conventional circuit breakers in Medium Voltage Alternating Current (MVAC) applications. One important system design characteristic that impacts the operation of SSCBs is the system inductance measured on either side of the SSCB. Because cable resistance is very small, this inductance limits the rate of current rise during a fault. A minimum inductance is required to enable the SSCB to interrupt the fault current within the time needed to detect, localize and isolate the fault. This paper provides a method for approximating the system inductance, offers strategies for increasing it should it prove to be too small, and discusses stability and pulsed load implications.