Electronic Commutator Circuits
1 Assignment
0 Petitions
Accused Products
Abstract
The electronic commutator circuits provide forced commutation enhancements that can be embedded within a known electronic commutator to overcome its low speed torque limitation. The forced commutation enhancements to the basic switched stage use a pair of thyristors. Capacitors may be pre-charged and synchronized to supplement coil voltages when discharged, thereby reducing commutation overlap duration and maximizing the turn-off time available to allow the thyristors to attain forward blocking capability. A capacitive discharge can be achieved by initiating the capacitive discharge by the same thyristor that will carry the current following the commutation, or by initiating the capacitive discharge by an auxiliary thyristor.
13 Citations
38 Claims
-
1-19. -19. (canceled)
- 20. An electronic commutator circuit for use with a stator winding of a brushless dc electrical machine, the stator winding having a number of coils linked by the same number of points of common coupling, the electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals and including capacitive commutation forcing means for selectively discharging a voltage into the stator winding.
-
37. A brushless dc rotating machine comprising a rotor, a stator, a stator winding having a number of coils linked by the same number of points of common coupling, and an electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals and including capacitive commutation forcing means for selectively discharging a voltage into the stator winding, wherein each switching stage of the electronic commutator circuit is connected between a respective one of the points of common coupling and the first and second dc terminals.
-
38. A dc linear machine comprising a translator, a stator, a stator winding having a number of coils linked by the same number of points of common coupling, and an electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals and including capacitive commutation forcing means for selectively discharging a voltage into the stator winding, wherein each switching stage of the electronic commutator circuit is connected between a respective one of the points of common coupling and the first and second dc terminals.
Specification