U.S. patent application number 10/538077 was filed with the patent office on 2006-03-09 for operation control apparatus for compressor and method thereof.
Invention is credited to Gyoo-Jong Bae, Young-Hoan Jun, Woo-Geun Lee, Dong-Hee Shin.
Application Number | 20060048530 10/538077 |
Document ID | / |
Family ID | 32677749 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060048530 |
Kind Code |
A1 |
Jun; Young-Hoan ; et
al. |
March 9, 2006 |
Operation control apparatus for compressor and method thereof
Abstract
In an operation control apparatus and a method thereof, the
compressor can be protected from overloading through a current
control device instead of an OLP (Over Load Protector) and a PTC
thermistor (Positive Temperature Coefficient thermistor). The
operation control apparatus includes: a stroke estimated unit for
estimating a stroke of the compressor on the basis of a current and
a voltage applied to an interior motor of the compressor and a
motor constant of the interior motor; a control unit for generating
a control signal for varying a stroke of the compressor on the
basis of the estimated stroke value and a preset stroke reference
value; and a current control means being turned on/off so as to
vary a stroke voltage applied to the interior motor of the
compressor.
Inventors: |
Jun; Young-Hoan;
(Changwon,Gyeongsangnam-Do, KR) ; Shin; Dong-Hee;
(Busan, KR) ; Bae; Gyoo-Jong;
(Changwon,Gyeongsangnam-Do, KR) ; Lee; Woo-Geun;
(Busan, KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
32677749 |
Appl. No.: |
10/538077 |
Filed: |
October 2, 2003 |
PCT Filed: |
October 2, 2003 |
PCT NO: |
PCT/KR03/02045 |
371 Date: |
June 9, 2005 |
Current U.S.
Class: |
62/228.1 |
Current CPC
Class: |
F04B 35/045 20130101;
F04B 2203/0401 20130101; F04B 2203/0402 20130101 |
Class at
Publication: |
062/228.1 |
International
Class: |
F25B 49/00 20060101
F25B049/00; F25B 1/00 20060101 F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2002 |
KR |
10-2002-0081875 |
Claims
1. An operation control apparatus for a compressor comprising: a
stroke estimating unit for estimating a stroke of the compressor on
the basis of a current and a voltage applied to an interior motor
of the compressor and a motor constant of the interior motor; a
control unit for generating a control signal for varying a stroke
of the compressor on the basis of the estimated stroke value and a
preset stroke reference value; and a current control means for
varying a stroke voltage applied to the interior motor of the
compressor in accordance with the control signal.
2. The apparatus of claim 1, wherein an OLP (Over Load Protector)
and/or a PTC thermistor (Positive Temperature Coefficient
thermistor) are not used for the operation control apparatus.
3. The apparatus of claim 1, wherein the control unit outputs the
control signal for increasing the stroke voltage applied to the
compressor when the compressor is initially driven, to the current
control means.
4. The apparatus for claim 1, wherein, when the estimated stroke
value is smaller than the stroke reference value, the control unit
increases a voltage applied to the compressor by lengthening an
on/off period of the current control means, and, when the estimated
stroke value is greater than the stroke reference value, the
control unit decreases a voltage applied to the compressor by
shortening the on/off period of the current control means.
5. An operation control apparatus for a compressor comprising:
detecting means for detecting a current and a voltage which are
applied to a compressor; a storing means for presetting a standard
current value for preventing an overcurrent generated when the
compressor initially starts, and storing the set standard current
value; a comparing means for comparing the detected current value
and the standard current value, and outputting a comparing signal
corresponding to the comparing result; and a control means for
cutting off a current applied to the compressor by turning off a
current control means installed at the compressor by the comparing
result, or for controlling a stroke voltage applied to the
compressor by turning on/off the current control means at a certain
period.
6. The apparatus of claim 5, wherein the current control means is
one of a triac, a GTO transistor (gate turn-off transistor), an
IGBT (Insulated Gate bipolar Transistor), a bipolar transistor and
a relay.
7. The apparatus of claim 5, wherein the compressor is installed at
a refrigerator.
8. The apparatus of claim 5, wherein the control means cuts off a
current applied to the compressor by turning off the current
control means when the detected current value is greater than the
standard current value; and compares the stroke value estimated
based on the detected voltage value, the detected current value and
a motor constant of an interior motor of the compressor with the
preset stroke reference value, and then varies a stroke of the
compressor on the basis of the comparing result when the detected
current value is smaller than the standard current value.
9. The apparatus of claim 5, wherein an OLP (Over Load Protector)
and/or a PTC thermistor (Positive Temperature Coefficient
thermistor) are not used for the operation control apparatus.
10. A method for controlling an operation of a compressor
comprising the steps of; detecting a current and a voltage applied
to the compressor; estimating a stroke of the compressor on the
basis of the detected values of the current and the voltage and a
motor constant of an interior motor of the compressor; when the
estimated stroke value is smaller than a preset stroke reference
value, increasing a voltage applied to the compressor by
lengthening an on/off period of a current control means installed
at the compressor, and when the estimated stroke value is greater
than a preset stroke reference value, decreasing a voltage applied
to the compressor by shortening the on/off period of the current
control means.
11. A method for controlling an operation of a compressor
comprising: detecting a current applied to the compressor;
comparing the detected current value and a preset standard current
value; cutting off a current applied to the compressor by turning
off a current control means installed at the compressor when the
detected current value is greater than the standard current value;
and when the detected current value is the same as or smaller than
the standard current value, estimating a stroke of the compressor,
and controlling a stroke voltage applied to the compressor by
turning on/off the current control means at a certain period on the
basis of the estimated value and the preset stroke standard current
value.
Description
TECHNICAL FIELD
[0001] The present invention relates to a compressor and,
particularly to an operation control apparatus for a compressor
used for a refrigerator and a method thereof.
BACKGROUND ART
[0002] Generally, in a compressor, particularly a reciprocating
compressor, compression efficiency is higher than a general
compressor since there is no crankshaft for converting a rotational
movement into a linear movement and thus a friction loss is
small.
[0003] In case that the reciprocating compressor is used for a
refrigerator or an air conditioner, as varying a stroke voltage
applied to the reciprocating compressor (interior motor of the
compressor), being able to vary a compression ratio, so that
freezing capacity can be controlled. The operation controlling
apparatus for the reciprocating compressor will now be described
with reference to FIG. 1.
[0004] FIG. 1 is a block diagram showing a configuration of the
operation control apparatus for the reciprocating compressor
according to a conventional art.
[0005] As shown therein, the reciprocating compressor according to
the conventional art includes an OLP (Over Load Protector) 11
electrically connected to a common terminal of a reciprocating
compressor 12 and cutting off power applied to the interior motor
(not shown) of the compressor 12 when a temperature of the
compressor 12 is high or an overcurrent flows into the interior
motor of the compressor 12; and a PTC thermistor (Positive
Temperature Coefficient thermistor) 13 electrically connected to a
sub-coil (not shown) of the compressor 12 and initially protecting
the compressor from being over-loaded by cutting off a current
applied to the compressor 12 when a temperature of the compressor
12 increases at an initial stage of driving.
[0006] Herein, the OLP 11 is electrically connected with the
compressor 12, and cuts off power applied to the interior motor of
the compressor 12 when a temperature of the compressor 12 is high
or an overcurrent flows into the interior motor of the compressor.
In addition, if an overload is generated at the compressor 12 due
to a rapid increase of a temperature generated when the compressor
12 starts initially, the PTC thermistor cuts off a current applied
to the interior motor of the compressor so as to protect the
compressor 12 from being over-loaded when the compressor 12
initially starts.
[0007] However, in the reciprocating compressor used for a
refrigerator according to the conventional art, a stroke increases
slowly so that an over current is not generated rapidly when the
compressor initially starts. Accordingly, the PTC thermistor 13 is
not required to be installed at the compressor, and a cost for
producing the compressor increases since the PTC thermistor 13 is
installed at the compressor 12.
[0008] In addition, since the OLP 11 is installed at the compressor
12 according to the conventional art, the operation control
apparatus can not be miniaturized by the size of a current device
(not shown) in the OLP 11. Also, a production cost of the
compressor 12 increases by installing the OLP 11 at the compressor
12.
DISCLOSURE OF THE INVENTION
[0009] Therefore, it is an object of the present invention to
provide an operation control apparatus for a compressor and its
method capable of protecting the compressor from being over-loaded
through a current control device instead of a PTC thermistor and an
OLP.
[0010] It is another object of the present invention to provide an
operation control apparatus for a compressor and its method capable
of reducing a production cost of the compressor by protecting the
compressor from being over-loaded through a current control device
instead of a PTC thermistor and an OLP.
[0011] To achieve the above objects, there is provided an operation
control apparatus for a compressor including: a stroke estimating
unit for estimating a stroke of the compressor on the basis of a
current and a voltage applied to an interior motor of the
compressor and a motor constant of the interior motor; a control
unit for generating a control signal for varying a stroke of the
compressor on the basis of the estimated stroke value and a stroke
reference value; and a current control means for varying a stroke
voltage applied to the interior motor of the compressor by being
turned on/off according to the control signal.
[0012] To achieve the above objects, there is also provided an
operation control apparatus for a compressor including: a detecting
means for detecting a current and a voltage applied to the
compressor; a storing means presetting a standard current value for
preventing an overcurrent generated when the compressor initially
starts, and storing the set standard current value; a comparing
means for comparing the detected current value and the standard
current value, and outputting a comparing signal corresponding to
the comparing result; and a control means for cutting off a current
applied to the compressor by turning off the current control means
installed at the compressor by the comparing signal, or controlling
a stroke voltage applied to the compressor by turning on/off the
current control means at a certain period.
[0013] To achieve the above objects, there is also provided a
method for controlling an operation of a compressor including the
steps of: detecting a current and a voltage applied to the
compressor; estimating a stroke of the compressor on the basis of
the detected values of a current and a voltage and a motor constant
of an interior motor of the compressor; and increasing a voltage
applied to the compressor by lengthening an on/off period of the
current control means installed at the compressor when the
estimated stroke value is smaller than a preset stroke reference
value, and decreasing a voltage applied to the compressor by
shortening the on/off period of the current control means when the
estimated stroke value is greater than the stroke reference
value.
[0014] To achieve the above objects, there is provided a method for
controlling an operation of a compressor including the steps of:
detecting a current applied to the compressor; comparing the
detected current value and a preset standard current value; cutting
off a current applied to the compressor by turning off a current
control means installed at the compressor when the detected current
value is greater than the standard current value; and, when the
detected current value is the same as or smaller than the standard
current value, estimating a stroke of the compressor, and
controlling a stroke voltage applied to the compressor by turning
on/off the current control means at a certain period on the basis
of the estimated value and a preset stroke reference value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a block diagram showing a configuration of an
operation control apparatus for a reciprocating compressor
according to the conventional art;
[0016] FIG. 2 is a block diagram showing a configuration of an
operation control apparatus for a reciprocating compressor
according to a first embodiment of the present invention;
[0017] FIG. 3 is a flow chart showing an operation order of an
operation control apparatus for a reciprocating compressor
according to a first embodiment of the present invention;
[0018] FIG. 4 is a block diagram showing a configuration of an
operation control apparatus for a reciprocating compressor
according to a second embodiment of the present invention; and
[0019] FIG. 5 is a flow chart showing an operation order of an
operation control apparatus for a reciprocating compressor
according to a second embodiment of the present invention.
MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS
[0020] Hereinafter, a preferred embodiment of an operation control
apparatus for a compressor and its method capable of preventing
damage to a compressor, which is caused by the overload
(overcurrent), by using a current control device without using the
OLP and the PTC thermistor, will now be described with reference to
FIGS. 2 to 5. Herein, the compressor is installed at a
refrigerator.
[0021] FIG. 2 is a block diagram showing a configuration of the
operation control apparatus for the reciprocating compressor
according to a first embodiment of the present invention. That is,
the amount of currents applied to the compressor 200 is controlled
through the current control device (triac, Tr) installed at the
compressor 200 without using the OLP (Over Load Protector) and the
PTC thermistor. Also, when the compressor initially starts, a
stroke of the compressor is estimated to slowly increase the stroke
of the compressor, and varies the stroke of the compressor by
turning on/off the current control device (Tr) at a certain period
on the basis of the estimated stroke.
[0022] As shown therein, the operation control apparatus for the
reciprocating compressor includes: a voltage detecting unit 102 for
detecting a voltage applied to an interior motor (not shown) of the
reciprocating compressor 200 when the reciprocating compressor is
operated; a current detecting unit 101 for detecting a current
applied to the interior motor of the compressor when the compressor
200 is operated; a stroke estimating unit 103 for estimating a
stroke of the compressor on the basis of a voltage value detected
from the voltage detecting unit 102, a current value detected from
the current detecting unit 101 and a motor constant of the interior
motor of the compressor; a control unit 104 for comparing the
estimated stroke value and a preset stroke reference value, and
generating a control signal on the basis of the comparing result;
and a power supply unit 105 for on-off controlling an interior
current control device (e.g. Triac, Tr) according to the control
signal generated from the control unit 104 and thus varying a
stroke voltage supplied to the interior motor of the reciprocating
compressor 200. Herein, a resistor (R) in the power supply unit 105
is installed to measure a current applied to the compressor 200. In
addition, the reciprocating compressor 200 varies an inner stroke
by receiving a stroke voltage provided to the interior motor
according to the stroke reference value set by a user, and
vertically moves a piston (not shown) in the compressor.
[0023] Hereinafter, an operation of the operation control apparatus
for the reciprocating compressor according to the first embodiment
of the present invention will now be described in detail with
reference to FIG. 3.
[0024] First, the reciprocating compressor 200 varies the stroke by
receiving a voltage supplied to the interior motor in depending on
the stroke reference value set by a user, and thus vertically moves
the piston. Herein, the stroke means a moving distance of the
piston in the reciprocating compressor 200 while the piston
reciprocally moves.
[0025] A turn-on period of the current control device of the power
supply unit 105 is lengthened by a control signal outputted from
the control unit 104. An alternating current power is supplied to
the reciprocating compressor 200 due to the lengthened turn-on
period, and thus the reciprocating compressor 200 is driven. At
this time the voltage detecting unit 102 and the current detecting
unit 101 detect a voltage and a current applied to the
reciprocating compressor 200 respectively, and then output the
detected value of the voltage and the current to the stroke
estimating unit 103 (S11). The stroke estimating unit 103 estimates
a stroke of the compressor 200 on the basis of the voltage value
detected from the voltage detecting unit 102, the current value
detected from the current detecting unit 101 and a motor constant
of the interior motor, and outputs the estimated stroke value to
the control unit 104 (S12).
[0026] The control unit 104 compares the estimated stroke value and
the preset stroke reference value, and outputs a control signal on
the basis of the comparing result (S13). That is, when the
estimated stroke value is smaller than the stroke reference value,
the control unit 104 outputs a control signal for lengthening the
turn-on period of the Tr to the Tr of the power supply unit 104 and
thus increases a stroke voltage supplied to the reciprocating
compressor 200. On the other hand, when the estimated stroke value
is greater than the stroke reference value, the control unit 104
outputs a control signal for shortening the turn-on period of the
Tr to the Tr of the power supply unit 105 and thus decreases a
stroke voltage supplied to the reciprocating compressor 200 (S14,
S15).
[0027] Herein, the current control device (Tr) is installed instead
of an OLP, and is on/off switched by the control signal of the
control unit 104 so as to be able to vary a stroke of the
compressor 200, or cut off a current applied to the interior motor
of the compressor. In addition, preferably, one of a triac, GTP
transistor (gate turn-off transistor or a gate turn-off thyristor),
an IGBT (Insulated Gate bipolar Transistor) a bipolar transistor
and a relay is used as the current control device.
[0028] Hereinafter, a configuration of an operation control
apparatus for the reciprocating compressor according to a second
embodiment of the present invention will now be described in detail
with reference to FIG. 4.
[0029] FIG. 4 is a block diagram showing the configuration of the
operation control apparatus for the reciprocating compressor
according to the second embodiment of the present invention. That
is, in the operation control apparatus for the reciprocating
compressor according to the second embodiment of the present
invention, a current control device (Tr) instead of the OLP and the
PTC thermistor is installed at the compressor 200, and the amount
of currents applied to the interior motor of the compressor 200 is
controlled through the current control device (Tr). Also, in the
operation control apparatus for the reciprocating compressor
according to the second embodiment of the present invention, in
order to protect the compressor 200 from an overcurrent generated
when the compressor 200 initially starts, a current applied to the
compressor 200 and a preset standard current is compared. Then,
according to the comparing result, a current applied to the
interior motor of the compressor 200 is cut off by turning off the
current control device (Tr) or a stroke of the compressor is
controlled by turning on/off the current control device (Tr) at a
certain period.
[0030] As shown in FIG. 4, the operation control apparatus for the
reciprocating compressor according to the second embodiment of the
present invention includes: a voltage detecting unit 102 for
detecting a voltage applied to an interior motor (not shown) of the
reciprocating compressor when the reciprocating compressor 200 is
operated; a current detecting unit 101 for detecting a current
applied to the interior motor of the compressor 200 when the
compressor 200 is operated; a stroke estimating unit 103 for
estimating a stroke of the compressor on the basis of a voltage
value detected from the voltage detecting unit 102, a current value
detected from the current detecting unit 101 and a motor constant
of the interior motor of the compressor; a standard current value
storing unit 106 for storing a preset standard current value to cut
off an overcurrent generated when the compressor initially starts;
a comparing unit 107 for comparing the current value detected from
the current detecting unit 101 and the standard current value
previously stored at the standard current value storing unit 106,
and outputting a comparing signal corresponding to the comparing
result; a control unit 104 for generating a cut-off signal for
cutting off a current applied to the interior motor of the
compressor on the basis of the comparing signal, or comparing the
estimated stroke value and the stroke reference value, and then
generating a control signal on the basis of the comparing result;
and a power supply unit 105 for cutting off a current applied to
the interior motor of the compressor 200 by turning off the inner
current control device by the cut-off signal generated from the
control unit 104, or controlling a stroke voltage applied to the
interior motor of the reciprocating compressor 200 by on-off
controlling the current control device (Tr) on the basis of the
control signal.
[0031] Herein, when the current value detected from the current
detecting unit 101 is greater than the standard current value
previously stored at the standard current value storing unit 106,
the control unit 104 generates a cut-off signal and outputs the
generated cut-off signal to the current control device (Tr) in the
power supply unit 105. At this time, the current control device
(Tr) is turned off based on the cut-off signal so as to cut off a
current applied to the interior motor of the compressor.
[0032] On the other hand, when the current value detected from the
current detecting unit 101 is the same as or smaller than the
standard current value previously stored at the standard current
value storing unit 106, the control unit 104 generates a control
signal and outputs the generated control signal to the current
control device (Tr) in the power supply unit 105. That is, when the
current value detected from the current detecting unit is the same
as or smaller than the standard current value previously stored at
the standard current value storing unit 106, the control unit 104
controls the turn-on period of the Tr in the power supply unit 105
and thus varies a stroke voltage applied to the interior motor of
the compressor 200.
[0033] Hereinafter, an operation of the operation control apparatus
for the reciprocating compressor according to a second embodiment
of the present invention will now be described in detail with
reference to FIG. 5.
[0034] FIG. 5 is a flow chart showing an operation order of an
operation control apparatus for a reciprocating compressor
according to the second embodiment of the present invention.
[0035] First, when the compressor 200 is operated, the current
detecting unit 101 detects a current applied to the interior motor
of the compressor 200 at a real time, and outputs the detected
current value to the stroke estimating unit 103 and the comparing
unit 107. At this time, when the compressor 200 is operated, the
voltage detecting unit 102 detects a voltage applied to the
interior motor of the compressor 200 at a real time, and outputs
the detected voltage value to the stroke estimating unit 103
(S21).
[0036] The stroke estimating unit 103 estimates a stroke of the
compressor 200 on the basis of the detected voltage value, the
detected current value and the motor constant of the interior
motor, and outputs the estimated value (the estimated stroke value)
to the control unit 104.
[0037] The comparing unit 107 compares the standard current value
previously stored at the standard current value storing unit 106
and the current value detected from the current detecting unit 101,
and outputs a signal corresponding to the comparing result to the
control unit 104.
[0038] When the current value detected from the current detecting
unit 101 is greater than the standard current value, the control
unit 104 generates a cut-off signal, and outputs the generated
cut-off signal to the current control device (Tr) (S22). At this
time, the current control device (Tr) is turned off based on the
cut-off signal so as to cut off a current applied to the interior
motor of the compressor (S23, S24).
[0039] On the other hand, when the current value detected from the
current detecting unit 102 is the same as or smaller than the
standard current value, the control unit 104 generates a control
signal, and outputs the generated control signal to the current
control device. That is, when the current value detected from the
current detecting unit 102 is the same as or smaller than the stand
current value, and the estimated stroke value is smaller than the
stroke reference value, the control unit 104 outputs a control
signal for lengthening a turn-on period of the Tr to the Tr and
thus increases a stroke voltage supplied to the interior motor of
the reciprocating compressor 200. On the other hand, when the
current value detected from the current detecting unit 102 is the
same as or smaller than the stand current value, and the estimated
stroke value is greater than the stroke reference value, the
control unit 104 outputs a control signal for shortening the
turn-on period of the Tr to the Tr and thus decreases the stroke
voltage supplied to the interior motor of the reciprocating
compressor 200. That is, a stroke of the compressor 200 is varied
by increasing or decreasing the stroke voltage (S25-S27).
[0040] Herein, the standard current value is preset by a user, and
means a current value, which should be applied to the motor so that
the interior motor of the compressor 200 is normally operated. That
is, the standard current value is set by previously measuring a
current value applied to the interior motor of the compressor when
the compressor is normally operated, and then storing the measured
value.
[0041] Accordingly, in the present invention, a damage of the
compressor 200, which is caused by an overload (overcurrent), can
be prevented without the OLP and the PTC thermistor, and the
compressor 200 can be controlled closely.
[0042] As so far described, in the present invention, a damage of a
compressor, which is caused by the overcurrent, can be prevented by
cutting off power applied to the interior motor of the compressor
when a compressor is operated, or by applying power to the interior
motor of the compressor, without using the OLP and the PTC
thermistor.
[0043] Also, in the present invention, since the conventional OLP
and the PTC thermistor is not used, but the operation control
apparatus for controlling a stroke of the compressor is used, the
stroke can be controlling closely, and a production cost of the
compressor can be reduced.
[0044] Also, in the present invention, a compressor can be
miniaturized by controlling an operation of the compressor through
the current control device without using the conventional OLP and
the PTC thermistor.
[0045] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover modifications and
variations of this invention provided they come within the scope of
the appended claims and their equivalents.
* * * * *