Pulse generator for a brushless direct-current rotor excited electrical machine having rotor mounted thyristors

Claim 1

In a brushless direct-current excited electrical rotating machine such as a reactive power machine or the like operable at constant or nearly constant rpm and having a rotor mounted on a rotor shaft, a field excitation winding mounted on the rotor, an exciting machine mounted on the rotor shaft and having a winding of at least one phase rotatable with the rotor shaft, controllable thyristors also rotatable with the rotor for supplying the field excitation winding with excitation current from the winding of the exciting machine, and a pulse generator for generating control voltages to trigger the thyristors, the pulse generator comprising a laminated rotor mounted on the rotor shaft and having a plurality of slots, a pulse generator winding disposed in said slots and having a number of poles corresponding to the number of poles of the exciting machine, said pulse generator winding also having a number of phases equal to a whole number, n, times the number of phases of the exciting machine where n > OR = 1, at least two laminated magnetic systems for inducing respective voltages in said pulse generator winding, each of said systems having the same pole pitch and being spaced from said laminated rotor the same air gap distance, said systems being fixedly disposed relative to said laminated rotor and displaced with respect to each other a distance corresponding to a given electrical angle so as to cause the voltages induced in said pulse generator winding to add to form a voltage adaptable for triggering the thyristors.