US 4,459,519 AGranted

Electronically commutated motor systems and control therefor

AssigneeGeneral Electric Company

InventorDavid M. Erdman

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Abstract

Electronically commutated motor and control arrangements particularly adapted for use with refrigeration systems and methods of operating refrigeration systems are disclosed. In one form, a fan control means is provided for responding to temperature of a compartment being cooled by a refrigeration system; comparing the compartment temperature with a desired temperature; and varying the speed of an evaporator fan, thereby varying the movement of refrigerated air across an evaporator and into the compartment. A regulating circuit is provided for maintaining the evaporator at a reference temperature by controlling the output signal of an alternator which supplies energization power to winding stages of a brushless DC motor. By varying the energization level of the winding stages, a compressor, which is coupled to the motor, is caused to vary the flow rate of refrigerant through the evaporator so as to maintain the evaporator at the reference temperature. The regulating circuit includes means for responding to a signal from the fan control means, which is indicative of the fan speed and relative compartment cooling demand, for changing the reference temperature for the evaporator thereby to cause variance in the temperature of air moved about the evaporator by the fan for controlling temperature within the compartment. The regulating circuit also includes: means for limiting and controlling motor winding current to a maximum value; means for limiting motor speed to a predetermined low value; means for limiting and controlling motor speed to a maximum high value; means for assuring a minimum energization level for the motor winding stages; means for limiting the energization level of the winding stages to a maximum voltage value; and means for inhibiting motor operation if the evaporator temperature is less than a predetermined low temperature value.

A brushless DC motor and control arrangement for use with a refrigeration system comprising an evaporator, a compressor for moving a refrigerant through the evaporator, an evaporator fan for moving air about the evaporator for maintaining a desired temperature within a compartment by moving refrigerated air thereto, and wherein said brushless DC motor is coupled to said compressor and comprises a stationary armature having a core and winding means arranged to establish at least two winding stages;

said winding means comprising concentric winding turns accommodated by said core and arranged to establish a predetermined number of magnetic poles, and the winding turns of each winding stage having a number of sets of axially extending conductor portions with such number equal to the predetermined number of magnetic poles;
the axially extending conductor portions within each given set being disposed in said armature to conduct current instantaneously in a common axial direction along the core thereby contributing to establishment of a magnetic pole when the winding stage containing the given set is energized;
a rotor having constant magnetic polar regions equal in number to the predetermined number of poles, said rotor being adapted to rotate in response to the magnetic poles established by the winding turns;
a commutation circuit for energizing the windings in a predetermined manner wherein said commutation circuit includes a detector circuit for sensing a back emf signal indicative of the back emf condition of at least one winding, position determining circuit means responsive to the emf signal from the detector circuit for integrating the emf signal to a predetermined value of volt-seconds whereupon the position determining circuit means produces a simulated relative position output signal;
means responsive to the simulated relative position output signal from the position determining circuit means for supplying an output signal for energizing a selected one of the winding stages;
and said control arrangement further including a regulating means adapted for controlling the supply of energization power to the winding stages;
said regulating means comprising means for responding to evaporator temperature and for varying the supply of power to the winding stages to thereby vary the speed of the brushless DC motor and control the flow rate of the refrigerant so as to maintain a selected portion of the evaporator at a first preselected reference temperature;
and said regulating means also comprising means for responding to a signal indicative of cooling demand within the compartment for automatically changing the first reference temperature of the selected portion of the evaporator in accordance with the relative cooling demand thereby to cause variance in the temperature of air moved about the evaporator for controlling temperature within the compartment.

5 more elements

Facts

Application

06/191,056Filed 25 Sep 1980 · continuation

Priority

24 Jun 1974

Granted

10 Jul 1984

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

F23N 3/082
By power-assisted systems: using electronic means
H02K 29/10
With position sensing devices: using light effect devices
H02P 6/16
Electronic commutators: circuit arrangements for detecting position
F23N 2233/04
In stacks: with variable speed

Family

Serial482,409Parent of this continuation-in-part · filed 24 Jun 1974

Serial729,761Parent of this continuation-in-part · filed 5 Oct 1976

Serial802,484Parent of this continuation-in-part · filed 1 Jun 1977

Serial943,490Parent of this continuation · filed 18 Sep 1978

US 4,005,347 AParent of this continuation-in-part

US 4,459,519 AThis patent

From the US filing history. Foreign family members aren’t listed.

Abstract

Claims11