Abstract: A method of performing de-excitation of a brushless synchronous machine having a stator; and a rotor including: a field winding, an exciter armature, a rectifier having thyristors, the rectifier having input terminals connected to the exciter armature and output terminals connected to the field winding, a field discharge resistor connected in series with the field winding, and a bypass switch connected in parallel with the field discharge resistor, the bypass switch being operable between a closed state in which the field discharge resistor is bypassed, and an open state, wherein the method including: a) controlling the thyristors to fire only during a negative half-cycle of the armature voltage waveforms, and b) controlling the bypass switch to obtain the open state from the closed state to thereby discharge a field winding current through the field discharge resistor.

Abstract: Unique systems, methods, techniques and apparatuses of a rotating DC power supply are disclosed. One exemplary embodiment includes a first and second DC bus rail, a first and second leg, and a discharge resistor. The first leg includes a first semiconductor device and a second semiconductor device coupled in series at a first midpoint connection, the first semiconductor device being coupled to a first point on the first DC bus rail and the first midpoint connection being coupled to a field winding. The second leg includes a third semiconductor device and a fourth semiconductor device coupled in series at a second midpoint connection, the third semiconductor device being coupled to a second point on the first DC bus rail and the second midpoint connection being coupled to the field winding. The discharge resistor is operatively coupled to the first DC bus rail between the first point and the second point.

Abstract: Unique systems, methods, techniques and apparatuses of a rotating DC power supply are disclosed. One exemplary embodiment includes a first and second DC bus rail, a first and second leg, and a discharge resistor. The first leg includes a first semiconductor device and a second semiconductor device coupled in series at a first midpoint connection, the first semiconductor device being coupled to a first point on the first DC bus rail and the first midpoint connection being coupled to a field winding. The second leg includes a third semiconductor device and a fourth semiconductor device coupled in series at a second midpoint connection, the third semiconductor device being coupled to a second point on the first DC bus rail and the second midpoint connection being coupled to the field winding. The discharge resistor is operatively coupled to the first DC bus rail between the first point and the second point.