D.C.-to-d.c. thyristor chopper for traction application

The paper discusses design principles together with a novel firing mode which enables the advantages of the resonant power controller to be utilised to produce a fixed-frequency chopper circuit, which has complete control over output power even at low output voltages. The resonant arrangement may be designed such that resonant currents are less than the peak load current to be commutated with a consequent reduction of the rating of the semiconductor and wound commutation components.