EP0218017A1
Expired / Lapsed
EP
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Electronically commutated motors
Assignee: General Electric Co
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Filing: 1981-04-16
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Granted: —
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Expires: 2001-04-16
Abstract
Abstract A control system for an electronically commutated motor (30) has a power conditioning circuit (72) for controlling the voltage (V M ) applied to the winding stages (a, b, c) of a stator (1161) by a commutation circuit (76) via a power switching circuit (74) so that the applied voltage (V M ) varies as a function of an input signal. The input signal is provided by a function generator (140) which selectively generates one of a plurality of electrically varying signals, corresponding to one of a plurality of waveshapes to which the rotor is to be selectively made to conform in at least one sense of rotation. The input signal is variable over many commutation periods according to the selected waveshape substantially independently from any variation of the applied voltage during any one of the commutation periods.
Inventors
- 👤 David Marvin Erdmann
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 21:35
CPC Classifications
F; F23; F23N; F23N3/00; F23N3/08; F23N3/082; D; D06; D06F; D06F34/00; D06F34/08; D06F37/00; D06F37/30; D06F37/304; H; H02; H02K; H02K29/00; H02K29/06; H02P; H02P6/00; H02P6/08; H02P6/085; H02P6/14; H02P6/16; D06F2103/00; D06F2103/44; D06F2103/46; D06F2105/00; D06F2105/46; F23N2233/00; F23N2233/02; F23N2233/04; F25; F25B; F25B2600/00; F25B2600/02; F25B2600/021; Y; Y02; Y02B; Y02B40/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
210 words
A control system for use with an electronically commutated motor (30) including a stationary assembly (1161) having a plurality of winding stages (a, b, c) associated therewith and adapted to be selectively commutated, and a rotatable assembly (1151) associated with the stationary assembly in selective magnetic coupling relation with the winding stages and with means (74, 76) for commutating the winding stages by applying a voltage thereto in at least one preselected sequence during successive commutation periods thereby to drive the rotatable assembly in at least one sense of rotation, the control system being characterised by means (72) for controlling the voltage (V M ) applied to the winding stages by the commutating means (74, 76) so that the applied voltage (V M ) varies as a function of an input signal thereto; and means (140) for selectively generating one of a plurality of electrically varying signals, corresponding to one of a plurality of waveshapes to which the at least one sense of rotation is to be selectively made to conform, as the input signal to said controlling means, the input signal being variable over many commutation periods in accordance with the selected waveshape substantially independently from any variation of the applied voltage during any one of the commutation periods.
Claim 2
Dependent Claim
210 words
A control system for use with an electronically commutated motor (30) including a stationary assembly (1161) having a plurality of winding stages (a, b, c) associated therewith and adapted to be selectively commutated, and a rotatable assembly (1151) associated with the stationary assembly in selective magnetic coupling relation with the winding stages and with means (74, 76) for commutating the winding stages by applying a voltage thereto in at least one preselected sequence during successive commutation periods thereby to drive the rotatable assembly in at least one sense of rotation, the control system being characterised by means (72) for controlling the voltage (V M ) applied to the winding stages by the commutating means (74, 76) so that the applied voltage (V M ) varies as a function of an input signal thereto; and means (140) for selectively generating one of a plurality of electrically varying signals, corresponding to one of a plurality of waveshapes to which the at least one sense of rotation is to be selectively made to conform, as the input signal to said controlling means, the input signal being variable over many commutation periods in accordance with the selected waveshape substantially independently from any variation of the applied voltage during any one of the commutation periods.
Claim 3
Dependent Claim
31 words
A control system according to claim 1 characterised in that said signal generating means includes means (140, 136) for also selectively generating a second input signal for said controlling means (72).
Claim 4
Dependent Claim
90 words
A control system according to claim 1 characterised in that said controlling means includes means (320, 418) for deriving voltage and current values representative respectively of the actual angular velocity of the rotatable assembly and the actual torque develoed thereby, means (322, 410) for comparing the respective derived voltage and current values with the input signal and the second input signal respectively to provide respective voltage and current error signals, and means (90) for adjusting the applied voltage under control of the voltage error signal and the current error signal.
Claim 5
Dependent Claim
72 words
A control system according to any one of the claims 1 to 3 characterised in that said signal generating means (140) includes means for electrically storing sets of values corresponding to points on the selected waveshapes, and for selecting one of the sets of values and scaling the values, and at a controlled rate successively supplying the scaled values of the selected one set as the input signal to said controlling means.
Claim 6
Dependent Claim
98 words
A control system according to claim 1 characterised in that the current flowing in the winding stages as a result of the applied voltage varies as a function of the input signal to said controlling means (72) and said signal generating means (140) includes means (140, 136) for generating waveshapes to which the torque during the at least one sense . of rotation is to be selectively made to conform, as the input signal to said controlling means, the at least one sense of rotation having substantially the same duration as the selectively generated one electrically varying signal.
Claim 7
Dependent Claim
69 words
A control system according to claim 1, 2, 4 or 5 characterised in that said controlling means (72) includes means (90) connected to the commutating means (74, 76) for producing the voltage ( VM ) from a full wave rectified sinusoidal voltage in response to a first signal so that the commutating means commutates at least some of the winding stages by applying the voltage (V M ) thereto.
Claim 8
Dependent Claim
136 words
A control system according to claim 6 characterised by means (322) for deriving a first error signal as a function of the difference between the actual angular velocity of the rotatable assembly and a desired angular velocity represented by the input signal from said signal generating means, means (356, 368, 370) for initiating a ramp signal at a predetermined time after the beginning of each of a plurality of successive half cycles of the full wave rectified sinusoidal voltage, and means (350) for comparing a sum of signals at least including the ramp signal and the first error signal in each of the successive half cycles with a reference voltage and, upon the sum exceeding the reference voltage, initiating the first signal to control the voltage producing means (90) in each of the successive half cycles.
Claim 9
Dependent Claim
96 words
Laundry apparatus having an electronically commutated motor energised by a control system according to any one of the claims 1 to 7, said laundry apparatus having means (12, 10) operable generally in a laundering mode for agitating fluid and fabrics to be laundered therein and operable generally in a spin mode for thereafter spinning the fabrics to effect centrifugal displacement of fluid from the fabrics, the rotatable assembly of the motor driving said agitating and spinning means in the laundering mode operation and in the spin mode operation thereof upon the commutation of the winding stages.
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