Design considerations for non-destructible fault current breakers in land mobile power converter systems

The Army is currently investigating new means of power conversion that eventually will lead toward new light weight hardware in order to improve land mobility. Application of solid state power technology has been of particular interest to the Army due to its potentially attractive cost to life cycle performance ratio. However, one of the important design considerations for this new equipment is correct fusing since some means for protection of components is necessary in case of a catastrophic failure elsewhere in the system. The presently available cartridge type thyristor fuse must be replaced after each catastrophic failure. This imposes latent logistic problems assuming the Army must stock fuses worldwide to sustain its global mission. It is in this context that various forms of re-usable fuse mechanisms are discussed, existing ways as well as proposed means, to protect solid state switches, especially thyristors, against catastrophic fault current amplitudes.