Electronic commutation method and related apparatus
First Claim
Patent Images
1. A method of controlling an electronically commutated motor having multiple phase windings by applying PWM drive signals in accordance with a series of commutation states, where a commutation event occurs when a rotor moves from a position associated with one commutation state to a position associated with another commutation state, the method comprising the steps of:
- (a) applying PWM drive signals at a set frequency on a cyclical basis;
(b) detecting a commutation event that is asynchronous with and occurs during an ongoing PWM drive signal cycle at a set frequency;
(c) responsive to detection of the asynchronous commutation event in step (b), increasing frequency of PWM drive signals applied during the ongoing PWM drive signal cycle to a frequency above the set frequency in order to reach the end of the ongoing PWM drive signal cycle more quickly than without such a frequency increase.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for electronic commutation of a pulse width modulation (PWM) controlled motor involves temporarily increasing the frequency of one or more PWM drive signals applied to the motor upon the occurrence of an asynchronous commutation event.
-
Citations
8 Claims
-
1. A method of controlling an electronically commutated motor having multiple phase windings by applying PWM drive signals in accordance with a series of commutation states, where a commutation event occurs when a rotor moves from a position associated with one commutation state to a position associated with another commutation state, the method comprising the steps of:
-
(a) applying PWM drive signals at a set frequency on a cyclical basis; (b) detecting a commutation event that is asynchronous with and occurs during an ongoing PWM drive signal cycle at a set frequency; (c) responsive to detection of the asynchronous commutation event in step (b), increasing frequency of PWM drive signals applied during the ongoing PWM drive signal cycle to a frequency above the set frequency in order to reach the end of the ongoing PWM drive signal cycle more quickly than without such a frequency increase. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A motor control system comprising:
-
a motor having multiple phase windings and a movable rotor, the position of the rotor defines multiple commutation states for the phase windings; a sensor arrangement for indicating the occurrence of commutation events when the rotor moves from a position associated with one commutation state to a position associated with another commutation state; and a controller for selectively energizing the phase windings with PWM drive signals, the controller operatively connected with the sensor arrangement and operable, upon occurrence of a commutation event that is asynchronous to an ongoing PWM drive signal of an initial frequency to increase frequency of the ongoing PWM drive signal to a frequency above the initial frequency in order to reach an end of cycle for the ongoing PWM drive signal more quickly than without such a frequency increase. - View Dependent Claims (8)
-
Specification