Theory and Application of the Commutation Principle for HVDC Circuit Breakers

The commutation principle for HVDC circuit breakers is described whereby the current in the circuit is brought to zero by a bucking current from a precharged capacitor. Circuit features are described to render this procedure easier for the interrupter and typical component requirements are discussed. The functions of current interruption and energy absorption should be separated; to this end, one type of surge suppressor is described. With breakers of this type, multi-terminal HVDC systems could be operated much like comparable AC systems, with only minimal dependence on terminal controls. A tapped line is given as an example.