Commutation configurations for the protection of a line commutated converter

Methods of protecting a line-commutated converter and load in the event of line-induced converter faults are investigated. The protection philosophy is classified in terms of the DC load type. Protection is found to be comprised of a two-part process, namely, detecting a fault and implementing corrective action during the postfault period. The latter process is described. To this end, four commutator configurations are presented, and simplified methods of analysis and their experimental verification are described. The four configurations are compared on the basic of criteria such as application suitability, component sizing, postfault peak line/load currents, and postfault time durations.