Influence of converters on the superconducting field-circuit of a three-phase synchronous generator

Experimental investigations of the influence of converter feeding the field circuit of a three-phase synchronous generator with a superconducting field winding have been performed. Four converter circuits have been tested: a B6 three-phase bridge, two parallel B6 three-phase bridges, a three-phase bridge with bypass thyristors, and a high-current power-MOSFET converter. Steady-state and transient operation have been tested. There was a special interest in the harmonics generated by the converter circuits and their power dissipation in the low-temperature region. The thermal reaction of the field circuit has also been considered. A method has been developed to prevent the superconducting winding from the quenching in transient operation