The dynamoelectric machine with devices for the rapid excitation degradation and method for fast excitation degradation in the case of buerstenlosen exciter machines

摘要

Thyristors are substituted for conventional diodes in the rotating rectifier assembly of a brushless exciter in a synchronous dynamoelectric machine. In contrast with prior systems in which thyristors are switched at relatively high ceiling voltages (requiring thyristors of high power rating and additional components for fast de-excitation), the gates of the thyristors in the present invention are fired only at a low voltage point of the negative half cycle of the polyphase armature voltage waveforms for fast de-excitation and are maintained in a fully conducting condition during the positive half cycle. This permits the use of thyristors having a relatively lower power rating and makes unnecessary additional components to achieve fast de-excitation.