Variable reluctance motor systems
First Claim
1. A variable reluctance electric motor system including a variable reluctance motor having a main winding for each of an even number of phases greater than two, and a power converter circuit including a main thyristor connected in series with each main winding of the motor across a source of direct voltage having a positive terminal and a negative terminal, with the current in each main winding being independent of that in the other main winding, and means for firing the main thyristors in sequence, the main windings of each pair being connected, one to the positive terminal of the source and the other to the negative terminal of the source, the one main winding having a commutating thyristor which connects the junction of the main thyristor and main winding to a capacitor unit so as, when fired, to allow the current flowing from the positive source terminal through the main winding to bypass the main thyristor, while charging the capacitor unit positively, and the other main winding having a commutating thyristor which connects the junction of its main thyristor and main winding to the said capacitor unit so as, when fired, to allow the other current flowing through the main winding to the negative source terminal to bypass the main thyristor while charging the capacity unit negatively, whereby a commutation of each main thyristor, initiated by firing its commutating thyristor and terminated when this commutating thyristor ceases to conduct leaves the capacity unit charged with the polarity opposite to the polarity prior to the commutation.
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Accused Products
Abstract
A variable reluctance electric motor system includes a variable reluctance motor having a main winding for each phase and a power converter circuit including a main thyristor in series with each main winding connected across a direct voltage source from which the main windings are supplied sequentially with uni-directional current pulses, characterized by a commutating thyristor (16) for starving the main thyristor (12) of the current flowing through one main winding (11) while charging a capacitor unit (51,52) in one sense, and a commutating thyristor (26) for starving the main thyristor (22) of the next phase winding (21) of the current flowing through the next main winding (21) while charging the capacitor unit in the other sense. The arrangement is such that commutation of a main thyristor initiated by firing a commutating thyristor and terminated when this commutating thyristor ceases to conduct, leaves the commutating capacitor unit charged with the correct polarity and adequate voltage for the commutation of the next main thyristor in the conducting sequence.
29 Citations
19 Claims
- 1. A variable reluctance electric motor system including a variable reluctance motor having a main winding for each of an even number of phases greater than two, and a power converter circuit including a main thyristor connected in series with each main winding of the motor across a source of direct voltage having a positive terminal and a negative terminal, with the current in each main winding being independent of that in the other main winding, and means for firing the main thyristors in sequence, the main windings of each pair being connected, one to the positive terminal of the source and the other to the negative terminal of the source, the one main winding having a commutating thyristor which connects the junction of the main thyristor and main winding to a capacitor unit so as, when fired, to allow the current flowing from the positive source terminal through the main winding to bypass the main thyristor, while charging the capacitor unit positively, and the other main winding having a commutating thyristor which connects the junction of its main thyristor and main winding to the said capacitor unit so as, when fired, to allow the other current flowing through the main winding to the negative source terminal to bypass the main thyristor while charging the capacity unit negatively, whereby a commutation of each main thyristor, initiated by firing its commutating thyristor and terminated when this commutating thyristor ceases to conduct leaves the capacity unit charged with the polarity opposite to the polarity prior to the commutation.
- 2. A variable reluctance electric motor system including a variable reluctance motor having a main winding for each of an even number of phases greater than two and a power converter circuit including a main thyristor in series with each main winding for connecting that main winding across a direct voltage source, from which the main windings are supplied sequentially with uni-directional current pulses, the current in each main winding being independent of those in the other main windings, and means for firing the main thyristors in sequence, a first commutating thyristor for allowing the current flowing through one main winding to bypass the main thyristor while charging a capacitor unit in one sense, and a second commutating thyristor allowing the current flowing through the next main winding to bypass its main thyristor while charging the capacitor unit in the other sense.
Specification