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Publication numberUS20030143080 A1
Publication typeApplication
Application numberUS 10/276,913
PCT numberPCT/KR2001/000867
Publication dateJul 31, 2003
Filing dateMay 24, 2001
Priority dateMar 26, 2001
Also published asCN1430702A, DE60108427D1, DE60108427T2, EP1373728A1, EP1373728A4, EP1373728B1, WO2002077453A1
Publication number10276913, 276913, PCT/2001/867, PCT/KR/1/000867, PCT/KR/1/00867, PCT/KR/2001/000867, PCT/KR/2001/00867, PCT/KR1/000867, PCT/KR1/00867, PCT/KR1000867, PCT/KR100867, PCT/KR2001/000867, PCT/KR2001/00867, PCT/KR2001000867, PCT/KR200100867, US 2003/0143080 A1, US 2003/143080 A1, US 20030143080 A1, US 20030143080A1, US 2003143080 A1, US 2003143080A1, US-A1-20030143080, US-A1-2003143080, US2003/0143080A1, US2003/143080A1, US20030143080 A1, US20030143080A1, US2003143080 A1, US2003143080A1
InventorsJae-Yoo Yoo, Gye-Young Song, Kyung-Bum Hur, Hyeong-Kook Lee
Original AssigneeJae-Yoo Yoo, Gye-Young Song, Kyung-Bum Hur, Hyeong-Kook Lee
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Driving controlling apparatus for reciprocating compressor
US 20030143080 A1
Abstract
A driving controlling apparatus for reciprocating compressor using resonance, uses resonance increased in the current corresponding characteristic by compensating the inductance valve of a coil turned inner part of the motor using a capacitor. A electric circuit further comprises a capacitor for compensating the inductance of the coil which is wound around the motor of the reciprocating compressing unit, accordingly, the burden of the applied voltage against the inductance is reduced, so low applied voltage can generate the stroke needed and the variation of the current hardly effect to the variation of the stroke. Therefore, stable load characteristic is maintained because the stroke variation is low even if the load variation is generated.
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Claims(3)
1. A driving controlling apparatus of a reciprocating compressor having a reciprocating compressing unit controlling a cooling force by varying a stroke according to a piston's movement by a voltage applied to an internal motor according to a stroke command value and an electric circuit unit for switching an AC power with a triac and applying it to the motor of the reciprocating compressing unit,
wherein the electric circuit unit includes a capacitor for offsetting an inductance of a coil wound at a motor itself of the reciprocating compressing unit.
2. The apparatus of claim 1, wherein the capacitor is positioned between the motor and a power supply unit.
3. The apparatus of claim 1, wherein the capacitor is positioned between the motor an the triac.
Description
TECHNICAL FIELD

[0001] The present invention relates a driving controlling apparatus of a reciprocating compressor using resonance, and more particularly, to a driving controlling apparatus of a reciprocating compressor using resonance with high current counteracting characteristics by offsetting an inductance value of a coil wound inside a motor by employing a capacitor.

BACKGROUND ART

[0002] In general, in a reciprocating compressor, power supplied to a coil wound at a polyphase stator is switched off by using a switching device to thereby generate a rotational torque. In this respect, by sequentially varying an excitation state between a rotor and a stator, a forward rotational torque can be generated by a magnetic suction force.

[0003] If a specific excitation state is not varied, the rotor can be stopped at a certain position, and by controlling a phase of an input pulse signal applied to the switching device by taking a maximum inductance as a starting point, a reverse-rotational force can be generated

[0004] With such various driving control availability, the reciprocating compressor is adopted for use to electric products requiring a direction control of the motor.

[0005] Especially, the reciprocating compressor used for a refrigerator or air-conditioner, a compression ratio can be varied by a voltage applied to the motor, and accordingly, a cooling force can be varied according to a user's intention.

[0006] The reciprocating motor will now be described in detail with reference to FIG. 1.

[0007]FIG. 1 is a block diagram showing the construction of a driving controlling apparatus of a general reciprocating compressor.

[0008] As shown in FIG. 1, the general reciprocating compressor includes: a reciprocating compressing unit (L.COMP) for varying a stroke by piston's movement to control a cooling force by a voltage applied to an internal motor according to a stroke command value; a voltage detector 30 for detecting a voltage generated at the reciprocating compressing unit (L.COMP) as the stroke is increased by the applied voltage; a current detector 20 for detecting a current applied to the reciprocating compressing unit (L.COMP) as the stroke is increased by the applied voltage; a microcomputer 40 for calculating a stroke with the voltage and the current detected by the voltage detector 30 and the current detector 20, comparing the stroke with the stroke command value and outputting a corresponding switching control signal; and an electric circuit unit 10 for switching off an AC power with a triac according to the switching control signal of the microcomputer 40 to apply a voltage to the reciprocating compressing unit (L.COMP).

[0009] The operation of the conventional reciprocating motor constructed as described will now be explained.

[0010] First, in the reciprocating compressing unit (L.COMP), the piston is moved by the voltage applied according to the stroke command value set by a user, and accordingly, a stroke is varied to control a cooling force.

[0011] Meanwhile, as the turn-on period of the triac (Tr1) of the electric circuit unit 10 is lengthened by the switching control signal of the microcomputer 40, the stroke of the reciprocating compressing unit (L.COMP) is increased. At this time, the voltage and current applied to the motor (M) of the reciprocating compressing unit (L.COMP) are detected by the voltage detector 30 and the current detector 20 and applied to the microcomputer 40.

[0012] Then, the microcomputer 40 calculates a stroke by using the voltage and current detected by the voltage detector 30 and the current detector 20.

[0013] The stroke is compared with the stroke command value to output a corresponding switching control signal.

[0014] That is, if the calculated stroke is smaller than the stroke command value, the microcomputer 40 outputs a switching control signal for lengthening the ON period of the triac (Tr1) in order to increase the voltage applied to the reciprocating compressing unit (L.COMP).

[0015] If, however, the calculated stroke is greater than the stroke command value, the microcomputer 40 outputs a switching control signal for shortening the ON period of the triac (Tr1) to reduce the voltage applied to the reciprocating compressing unit (L.COMP).

[0016] The relation between the voltage applied to the motor (M) and the stroke can be expressed by the following equation (1) V = L i t + R i + α S -> ( 1 )

[0017] wherein α indicates a motor constant for converting an electric force to a mechanic force, {overscore (S)} indicates a stroke, “R” is a internal resistance of the motor, and “L” indicates an inductance of the motor (M) itself.

[0018] The inductance voltage ( L i t )

[0019] is almost similar to a back electromotive force (α{overscore (S)}), and the voltage by the internal resistance (R) can be negligible compared with the back electromotive force (α{overscore (S)}).

[0020] Accordingly, the voltage (V) applied to the motor (M) is determined by sum of the inductance voltage ( L i t )

[0021] and the back electromotive force (α{overscore (S)}), and in order to generate a required stroke, the voltage (V) applied to the motor should be increased.

[0022] At this time, in order to improve an efficiency of the reciprocating compressor, the inductance (L) value of the coil wound on the motor (M) itself should be small, and the inductance (L) value of the coil becomes small as the size of the motor (magnet) is increased.

[0023] Thus, in order to improve the efficiency of the reciprocating motor, if the size of the mover (the thickness of the magnet) is increased, an air gap is increased, causing a problem that the overall size and cost of the reciprocating compressor is increased.

[0024] Meanwhile, if the size of the mover (the thickness of the magnet) is reduced, the inductance (L) value of the coil wound at the motor (M) is increased. Then, the current according to the voltage value for the stroke control of the reciprocating compressor would slowly work, so that the stroke is not smoothly controlled.

TECHNICAL GIST OF THE PRESENT INVENTION

[0025] Therefore, an object of the present invention is to provide a driving controlling apparatus of a reciprocating compressor which has an excellent current counteracting capacity by offsetting a quality which slows current operation characteristics as an inductance value of a coil wound inside a motor is increased by employing a capacitor.

DETAILED DESCRIPTION OF THE INVENTION

[0026] In order to achieve the above objects, there is provided a driving controlling apparatus of a reciprocating compressor having a reciprocating compressing unit controlling a cooling force by varying a stroke according to a piston's movement by a voltage applied to an internal motor according to a stroke command value and an electric circuit unit for switching an AC power with a triac and applying it to the motor of the reciprocating compressing unit, wherein the electric circuit unit includes a capacitor for offsetting an inductance of a coil wound at a motor itself of the reciprocating compressing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a block diagram showing the construction of a driving controlling apparatus of a conventional reciprocating compressor; and

[0028]FIG. 2 is a block diagram showing the construction of a driving controlling apparatus of a reciprocating compressor using a resonance according to the present invnetion.

MODE FOR CARRYING OUT THE PREFERRED EMBODIMENTS

[0029] The operation and effect of a driving controlling apparatus of a reciprocating compressor will now be described in detail with reference to the accompanying drawings.

[0030]FIG. 2 is a block diagram showing the construction of a driving controlling apparatus of a reciprocating compressor using a resonance according to the present invnetion.

[0031] As shown in FIG. 2, a driving controlling apparatus of a reciprocating compressor includes: a reciprocating compressing unit (L.COMP) for varying a stroke by piston's movement to control a cooling force by a voltage applied to an internal motor according to a stroke command value; a voltage detector 30 for detecting a voltage generated at the reciprocating compressing unit (L.COMP) as the stroke is increased by the applied voltage; a current detector 20 for detecting a current applied to the reciprocating compressing unit (L.COMP) as the stroke is increased by the applied voltage; a microcomputer 40 for calculating a stroke with the voltage and the current detected by the voltage detector 30 and the current detector 20, comparing the stroke with the stroke command value and outputting a corresponding switching control signal; and an electric circuit unit 10 having a capacitor (C) to offset an inductance of a coil (L) wound at the motor (M) itself of the reciprocating compressing unit (L.COMP) and switching off an AC power with a triac according to the switching control signal of the microcomputer 40 to apply a voltage to the reciprocating compressing unit (L.COMP).

[0032] The operation of the driving controlling apparatus of a reciprocating compressor will now be described in detail.

[0033] First, the piston is moved by an applied voltage according to a stroke command value set by a user, and accordingly, a stroke is varied to control a cooling force.

[0034] Meanwhile, as the turn-on period of the triac (Tr1) of the electric circuit unit 10 is lengthened by the switching control signal of the microcomputer 40, the stroke of the reciprocating compressing unit (L.COMP) is increased. At this time, the voltage and current applied to the motor (M) of the reciprocating compressing unit (L.COMP) are detected by the voltage detector 30 and the current detector 20 and applied to the microcomputer 40.

[0035] Then, the microcomputer 40 calculates a stroke by using the voltage and current detected by the voltage detector 30 and the current detector 20.

[0036] The stroke is compared with the stroke command value to output a corresponding switching control signal.

[0037] In this respect, in the present invention, the capacitor (C) is connected in series to the motor (M) to offset an inductance (L) of a coil wound at the motor (M), which will now be described in detail.

[0038] First, a voltage (V) applied to both ends of the motor (M) and the capacitor (C) can be deduced to the following equation (2): V = L i t + 1 C i t + R i + α S -> ( 2 )

[0039] At this time, a capacitance can be set by the following equation (3): C = 1 ( 2 π f ) 2 L ( 3 )

[0040] At this time, the capacitance (C) and the inductance (L) are previously set with values causing a resonance.

[0041] Accordingly, since the capacitance (C) and the inductance (L) are mutually resonated and offset, so that the voltage (V) applied to both ends of the motor (M) and the capacitor is deduced to the following equation (4):

[0042] ti V=Ri+α{overscore (S)}  (4)

[0043] In equation (4), the applied voltage (V) has the similar size to the back electromotive force (α{overscore (S)}) as the inductance voltage ( L i t )

[0044] is offset by the capacitor voltage ( 1 C i t ) ,

[0045] and accordingly, a required stroke is generated at the low applied voltage (V).

[0046] In addition, since the voltage filled in the capacitor (C) is applied to the motor (M) like the applied voltage (V), a big stroke is generated with the small applied voltage. Thus, an overload counteracting capacity is improved.

[0047] Industrial Applicability

[0048] As so far described, according to the driving controlling apparatus of a reciprocating compressor, since the current operation characteristics according to the increase in the inductance of the coil inside the motor is offset by employing the capacitor, the load of the applied voltage to inductance is reduced, and thus, a required stroke can be generated with the low applied voltage.

[0049] In addition, since the current change makes a little influence on the stroke variation, even though a load change occurs, the stroke variation is small, so that stable load characteristics are obtained.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2151733May 4, 1936Mar 28, 1939American Box Board CoContainer
CH283612A * Title not available
FR1392029A * Title not available
FR2166276A1 * Title not available
GB533718A Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7520730 *Jan 12, 2005Apr 21, 2009Lg Electronics Inc.Apparatus and method for controlling operation of compressor
US7628591 *Jan 11, 2005Dec 8, 2009Lg Electronics Inc.Apparatus and method for controlling operation of compressor
US8109736 *Dec 28, 2006Feb 7, 2012Lg Electronics Inc.Apparatus and method for controlling operation of a linear compressor using a phase difference inflection point detecting unit
US8221090 *Oct 18, 2006Jul 17, 2012Lg Electronics Inc.Reciprocating compressor stroke control by compensating motor inductance influences
Classifications
U.S. Classification417/44.1, 417/45, 417/44.11
International ClassificationF04B49/06, F04B35/04, F04B49/00
Cooperative ClassificationF04B35/045
European ClassificationF04B35/04S
Legal Events
DateCodeEventDescription
Nov 20, 2002ASAssignment
Owner name: LG ELECTRONICS INC., KOREA, REPUBLIC OF
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YOO, JAE-YOO;SONG, GYE-YOUNG;HUR, KYUNG-BUM;AND OTHERS;REEL/FRAME:013866/0868
Effective date: 20021111