Digital pulse width modulation control of brushless DC motors
First Claim
1. A torque controller for a brushless DC motor having an armature which is rotatably driven by at least one pair of armature windings and a resolver driven by the armature which functions in the sensing of the rotational position of the armature by the application of a time varying electrical signal A to a resolver excitation winding which is picked up by first and second sensing windings which respectively produce signals equal to Asine θ
- and Acosine θ
wherein θ
is the angular position of the armature and resolver comprising;
(a) means for applying a variable torque command A to said resolver excitation winding for controlling the torque produced by said armature;
(b) means for detecting the time varying signal Asine θ
picked up by said first sensing winding;
(c) means for detecting the time varying signal Acosine θ
picked up by said second sensing winding; and
(d) means for controlling the at least one pair of armature windings as a function of the torque command A.
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Abstract
An improved torque control for a brushless DC motor is disclosed. A torque command A of a time varying nature is applied to an excitation winding which is magnetically coupled through a resolver to produce output signals respectively on sensing windings of Acosine θ and of Asine θ wherein θ is the angular position of an armature and resolver of the motor. Armature windings respectively coupled to the sensing windings are driven by signals proportional to or equal to the signals sensed by the sensing windings to produce a torque equal to A.
23 Citations
14 Claims
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1. A torque controller for a brushless DC motor having an armature which is rotatably driven by at least one pair of armature windings and a resolver driven by the armature which functions in the sensing of the rotational position of the armature by the application of a time varying electrical signal A to a resolver excitation winding which is picked up by first and second sensing windings which respectively produce signals equal to Asine θ
- and Acosine θ
wherein θ
is the angular position of the armature and resolver comprising;(a) means for applying a variable torque command A to said resolver excitation winding for controlling the torque produced by said armature; (b) means for detecting the time varying signal Asine θ
picked up by said first sensing winding;(c) means for detecting the time varying signal Acosine θ
picked up by said second sensing winding; and(d) means for controlling the at least one pair of armature windings as a function of the torque command A. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- and Acosine θ
Specification