KR100783218B1 - Control apparatus for linear compressor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear compressor, and more particularly, to a control device of a linear compressor that performs cooling power variation and prevention of an inrush current.

A control device of a linear compressor according to the present invention comprises a coil winding body laminated in the circumferential direction of a linear compressor and having at least one or more winding tabs formed thereon, a first capacitor having one end connected in series to the coil winding body, A capacitance variable portion having one end connected to the winding tab of the coil winding body and the other end connected to the other end of the first capacitor and having a parallel structure with the first capacitor; and a control portion for controlling the total capacitance of the control device by controlling the capacitance variable portion And a controller for changing the output of the linear compressor.

Description

[0001] CONTROL APPARATUS FOR LINEAR COMPRESSOR [0002]

1 is a configuration diagram of a control apparatus of a linear compressor according to the prior art.

2 is a sectional view showing a linear compressor according to the present invention.

3 is a configuration diagram of a first embodiment of a control apparatus for a linear compressor according to the present invention.

4 is a configuration diagram of a second embodiment of a control apparatus for a linear compressor according to the present invention.

5 is a flow chart of the first embodiment of the control method for the control apparatus of Figs. 3 and 4. Fig.

Fig. 6 is a flowchart of a second embodiment of the control method for the control apparatus of Figs. 3 and 4. Fig.

Description of the Related Art

40: On-off switch 50, 50a: Capacitance variable part

60:

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear compressor, and more particularly, to a control device of a linear compressor that performs cooling power variation and prevention of an inrush current.

Generally, a compressor is a mechanical device that receives power from an electric motor or turbine, and compresses air, refrigerant or various other operating gases to increase the pressure. The compressor is used in a household appliance such as a refrigerator and an air conditioner, It is widely used throughout.

Such a compressor is broadly classified into a reciprocating compressor that compresses the refrigerant while linearly reciprocating the piston inside the cylinder so as to form a compression space in which a working gas is sucked and discharged between the piston and the cylinder. A rotary compressor for compressing the refrigerant while eccentrically rotating the roller along the inner wall of the cylinder so as to form a compression space in which a working gas is sucked and discharged between the rollers and the cylinders rotating eccentrically; A scroll compressor for compressing the refrigerant while the orbiting scroll is rotated along the fixed scroll so that a compression space in which the working gas is sucked and discharged is formed between the orbiting scroll and the fixed scroll, Is divided.

Generally, a linear compressor sucks, compresses, and discharges a refrigerant using a linear driving force of a motor. The linear compressor mainly includes a compression unit including a cylinder and a piston for compressing refrigerant gas, and a linear motor for supplying a driving force to the compression unit And is divided into a driving part included.

Specifically, the linear compressor is installed so that a cylinder is fixed in a hermetically sealed container, and a piston is reciprocally linearly movably installed in the cylinder, and as the piston reciprocates linearly in the cylinder, And a suction valve assembly and a discharge valve assembly are installed in the compression space to regulate the inflow and discharge of the refrigerant according to the pressure inside the compression space.

In addition, a linear motor for generating a linear motion force to the piston is installed so as to be connected to each other. In the linear motor, an inner stator and an outer stator are arranged with a predetermined clearance so that a plurality of laminations are stacked in the circumferential direction around the cylinder A coil (or coil winding body) is wound around the inner stator or the outer stator, and a permanent magnet is installed in the gap between the inner stator and the outer stator so as to be connected to the piston.

At this time, the permanent magnet is installed to be movable in the direction of movement of the piston, and reciprocates linearly in the direction of movement of the piston by an electromagnetic force generated as a current flows through the coil. In general, Not only is it operated at the frequency f _c , but also allows the piston to linearly reciprocate to a predetermined stroke S.

1 is a configuration diagram of a control apparatus of a linear compressor according to the prior art. As shown in the figure, the control device includes a coil winding body L which is wound around the linear compressor and is supplied with power, a branching stage 100 for applying power to a part or the whole of the coil winding body L, And a controller 200 for controlling the branching means 100 to adjust the cooling power according to the load.

More specifically, one end of the coil winding body L is connected to a power source, and a connection terminal 100a of the branching means 100 is formed at the other end of the coil winding body L. The connection terminal 100b is connected to the coil winding- A switching element 100c connected to the intermediate point M of the connection point L or a branch line of the intermediate point M and applying power to the connection terminal 100a or 100b under the control of the controller 200 ) Are included in the branching means (100).

The control unit 200 may be configured to perform a power mode in which power is applied to a part of the coil winding body L in order to output a high cooling power at the time of overload in the refrigeration cycle, So that a power saving mode in which power is applied to the entire coil winding body L is performed in order to output a low cooling power or an intermediate cooling power at an intermediate load. For this purpose, the controller 200 controls the switching element 100c of the branching means 100 to be connected to the connection terminal 100b, or the controller 200 controls the switching of the branching means 100 So that the switching element 100c is connected to the connection terminal 100a.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control apparatus for a linear compressor which controls an output by varying a capacitance of an overall control apparatus while preventing an inrush current accordingly.

It is another object of the present invention to provide a control apparatus for a linear compressor that performs control on an on-off switch of a linear compressor to prevent an inrush current when the capacitance is variable.

A control device of a linear compressor according to the present invention comprises a coil winding body laminated in the circumferential direction of a linear compressor and having at least one or more winding tabs formed thereon, a first capacitor having one end connected in series to the coil winding body, A capacitance variable portion having one end connected to the winding tab of the coil winding body and the other end connected to the other end of the first capacitor and having a parallel structure with the first capacitor; and a control portion for controlling the total capacitance of the control device by controlling the capacitance variable portion And a controller for changing the output of the linear compressor.

Preferably, the capacitance variable unit comprises at least one second capacitor and a capacitor switch for controlling current flow between the second capacitor and the winding tab.

Preferably, the control device further includes an on-off switch of the linear compressor.

In addition, the control unit preferably turns off the on-off switch in order to control the capacitance variable unit.

Preferably, the controller turns off the capacitor switch after turning off the on-off switch.

According to the present invention, there is also provided a control apparatus for a linear compressor including: a coil winding body laminated in a circumferential direction of a linear compressor; a first capacitor having one end connected in series to the coil winding body; a first capacitor connected in parallel to the first capacitor, And a control unit for controlling the capacitance variable unit to vary the total capacitance of the control unit to induce a change in output of the linear compressor.

Hereinafter, the present invention will be described in detail based on embodiments of the present invention and the accompanying drawings, in which a linear motor of a moving magnet type is operated and a piston connected thereto is linearly reciprocated in a cylinder to thereby suck, compress and discharge a refrigerant. Which will be described in detail by way of example. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the content of the following claims.

2, the linear compressor according to the present invention is provided with an inlet pipe 2a and an outlet pipe 2b through which a refrigerant flows in and out of a sealed container 2 at one side thereof, A piston 6 is installed in the cylinder 4 so as to be capable of reciprocating linear motion so as to compress the refrigerant sucked into the compression space P in the cylinder 4, Various springs are installed to be elastically supported in the direction of motion of the piston 6, and the piston 6 is installed to be connected to the linear motor 10 which generates a linear reciprocating driving force.

A suction valve 22 is provided at one end of the piston 6 in contact with the compression space P and a discharge valve assembly 24 is installed at one end of the cylinder 4 in contact with the compression space P The suction valve 22 and the discharge valve assembly 24 are automatically adjusted so as to be opened and closed in accordance with the pressure inside the compression space P, respectively.

Here, the closed container 2 is provided so that the upper and lower shells are coupled to each other so that the inside of the closed container 2 is hermetically sealed. An inlet pipe 2a through which the refrigerant flows into one side and an outlet pipe 2b through which the refrigerant flows out are provided. The linear motor 10 is mounted on the outer side of the cylinder 4 by the frame 18 so as to constitute an assembly. And the assembly is mounted on the inner bottom surface of the closed container 2 so as to be resiliently supported by the support springs 29.

A predetermined oil is contained in the bottom surface of the closed container 2 and an oil supply device 30 for pumping oil is installed at the bottom of the assembly. In addition, oil is supplied into the lower frame 18 through the piston 6 An oil supply pipe 18a is formed so as to be supplied between the cylinders 4 so that the oil supply device 30 is operated by the vibration generated as the reciprocating linear motion of the piston 6 to pump the oil, The oil is supplied along the oil supply pipe 18a to the clearance between the piston 6 and the cylinder 4 to cool and lubricate it.

Next, the cylinder 4 is formed in a hollow shape so that the piston 6 can reciprocate linearly. In addition, a compression space P is formed on one side of the cylinder 4, and one end of the cylinder 4 is positioned close to the inside of the inflow pipe 2a. And it is preferably provided on the same straight line as the inflow pipe 2a.

Of course, the cylinder 4 is provided with one end of the piston 6 that is reciprocatingly linearly movable in one end close to the inflow pipe 2a, and the discharge valve assembly 24 is provided at one end of the cylinder 4 opposite to the inflow pipe 2a Respectively.

The discharge valve assembly 24 includes a discharge cover 24a provided to form a predetermined discharge space on one end side of the cylinder 4 and a discharge valve 24b provided to open and close one end of the cylinder on the compression space P side And a valve spring 24c which is a kind of coil spring that applies an elastic force in the axial direction between the discharge cover 24a and the discharge valve 24b. An O-ring R is provided around one end of the cylinder 4, So that the discharge valve 24a is brought into close contact with one end of the cylinder 4. [

A loop pipe 28 formed to be bent is connected to one side of the discharge cover 24a and the outlet pipe 2b. The loop pipe 28 guides the compressed refrigerant to be discharged to the outside The vibrations due to the interaction of the cylinder 4, the piston 6 and the linear motor 10 are buffered from being transmitted to the entire airtight container 2.

When the pressure of the compression space P becomes equal to or higher than a predetermined discharge pressure as the piston 6 reciprocates linearly in the cylinder 4, the valve spring 24c is compressed to open the discharge valve 24b And the refrigerant is discharged from the compression space P and then completely discharged to the outside along the loop pipe 28 and the outlet pipe 2b.

The refrigerant passage 6a is formed at the center of the piston 6 so that the refrigerant flowing from the inlet pipe 2a can flow. One end of the piston 6 close to the inlet pipe 2a is connected to the linear motor A suction valve 22 is installed at one end of the inlet pipe 2a opposite to the inlet pipe 2a and is elastically supported by various springs in the direction of movement of the piston 6. [

At this time, the suction valve 22 is formed in a thin plate shape so that a central portion thereof is partially cut so as to open and close the refrigerant passage 6a of the piston 6, and one side of the suction valve 22 is fixed to one end of the piston 6a with a screw Respectively.

Therefore, when the pressure in the compression space P becomes equal to or lower than a predetermined suction pressure lower than the discharge pressure as the piston 6 reciprocates linearly in the cylinder 4, the suction valve 22 is opened, The refrigerant in the compression space P is compressed when the suction valve 22 is closed when the pressure in the compression space P becomes equal to or higher than a predetermined suction pressure.

Particularly, the piston 6 is installed to be elastically supported in the direction of movement. Specifically, a piston flange 6b protruding radially from one end of the piston 6 adjacent to the inlet pipe 2a is connected to a mechanical spring 8a and 8b so that the refrigerant contained in the compression space P opposite to the inlet pipe 2a acts as a gas spring due to the self- .

Here, the mechanical springs (8a, 8b) will be of a constant mechanical spring constant (K _m), regardless of the load, the mechanical spring (8a, 8b) is the ridge near the motor 10 on the basis of the piston flange (6b) A mechanical spring 8a supported on the support frame 26 and a machine 4 mounted on the cylinder 4. The mechanical spring 8a supported on the support frame 26 and the cylinder 4 that the spring (8a) so that two kinds of configuration the same mechanical spring constant (K _m) is preferred.

3 is a configuration diagram of a first embodiment of a control apparatus for a linear compressor according to the present invention.

2, the linear motor 10 includes an inner stator 12 that is configured to laminate a plurality of laminations 12a in the circumferential direction and is fixed to the outside of the cylinder 4 by a frame 18, And a plurality of laminations 14b are stacked in the circumferential direction around the coil winding body 14a configured to wind the inner stator 12 and the inner stator 12 by a predetermined gap And an outer stator 14 disposed in the gap between the inner stator 12 and the outer stator 14 and connected to the piston 6 by the connecting member 17 And the coil winding hull 14a may be fixed to the outside of the inner stator 12.

3, the control device of the linear compressor includes an on / off switch SW1 (40) to be supplied with power and to be supplied to the motor 10, a coil winding body A capacitor C1 connected in series with the coil winding body L and a capacitance variable portion 50 connected in parallel to the capacitor C1 are connected in parallel to the coil winding body L, And a control unit 60 for controlling the capacitance variable unit 50 to change the output of the linear compressor.

Specifically, the on-off switch (SW1) 40 corresponds to a main switch that applies power to the linear motor 10 under the control of the control unit 60. [ Here, the power source is an external commercial power source, or a power source applied from a power supply part of a device (for example, a refrigerator or the like) to which the linear compressor is mounted.

Next, the capacitor C1 and the capacitance variable portion 50 determine the total capacitance of the linear motor 10 and are connected in parallel as shown.

The capacitance variable section 50 is formed by a series connection of the capacitor C2 and the capacitor switch SW2 and the inrush current prevention element 52. [ A plurality of capacitance varying units 50 may be connected to the capacitor C1 in parallel.

Here, the capacitor C2 is connected to a capacitor having a capacitance smaller than that of the capacitor C1. The capacitor switch SW2 controls the connection of the coil winding body L so that a current or voltage from the power source is applied to the coil winding body L through the capacitor C2. The control section 60 controls the capacitance variable section 50 Means that the on / off of the capacitor switch SW2 is controlled.

When the capacitor switch SW2 is turned on in a state in which the on-off switches SW1 and SW40 are closed, the inrush current prevention element 52 instantaneously charges the capacitor C1 to the capacitor C2. The contact of the capacitor switch SW2 can be welded to prevent the breakage of the capacitor switch SW2 due to the rush current. The inrush current prevention element 52 is a resistor or a negative temperature coefficient (NTC) element or an inductor in order to prevent the inrush current from being excessively applied to the capacitor switch SW2 by converting the inrush current into another type of energy. And at least one of them.

The control unit 60 controls the above-described capacitance variable unit 50 to vary the total capacitance of the linear motor 10 to vary the operating frequency due to the variable capacitance and the coil winding body L, The output of the compressor, that is, the cooling power, can be changed. In particular, the output of the linear compressor must vary in size depending on the load, but the output of the linear compressor may be increased or decreased regardless of the magnitude of the load. The control of the control unit 60 for such output change and prevention of inrush current will be described with reference to Figs. 5 and 6 below.

4 is a configuration diagram of a second embodiment of a control apparatus for a linear compressor according to the present invention.

4, the controller of the linear compressor includes an on / off switch SW1 (40) to be supplied with power and to be supplied to the motor 10, a coil winding body (L) wound around the linear compressor in the circumferential direction, A capacitor C1 connected in series with the coil winding body L and a capacitor C1 having one end connected to one end of the capacitor C1 and the other end connected to the coil winding body L (the same element as the coil winding body 14a in Fig. 2) And a control unit 60 for controlling the capacitance variable unit 50a to change the output of the linear compressor. The capacitance variable unit 50a is connected to the coil tap T of the capacitor C1 and connected in parallel to the capacitor C1.

Here, the on-off switch (SW1) 40 and the coil winding body (L) and the capacitor C1 in Fig. 4 are the same elements as the elements having the same identification numbers in Fig.

The capacitance variable portion 50a of FIG. 4 is formed by a series connection of a capacitor C3 and a capacitor switch SW2. In particular, the capacitance variable portion 50a of FIG. 4 does not include the inrush current prevention element 52 and the other end is connected to the winding tab T of the coil winding body L, unlike the capacitance variable portion 50 of FIG. Since the coil between the capacitor C1 and the winding tab T functions as an inductor, the inrush current is prevented from breaking the capacitor switch SW2 when an inrush current is generated in the case described above . By connecting the capacitance variable portion 50a and the coil winding body L, it is not necessary to provide a separate inrush current prevention element mentioned in FIG. 3, thereby reducing the area occupied by the entire linear motor 10 In addition, a reduction in production cost is achieved. In particular, although the inrush current is consumed by the heat generated in the case of the resistor, since the heat generated by the current is continuously generated during the operation, there may arise a problem of raising the temperature of the linear motor 10, The effect of preventing the inrush current may be deteriorated. In the case of the inductor, since the size of the inductor is relatively large, the area occupied by the linear compressor may become considerably large. Therefore, 50a and the coil winding body L can be solved.

A plurality of the capacitance variable portions 50a may be connected to the capacitor C1 in parallel. The number of the coil taps T for the capacitance variable portion 50a may be one or more.

Here, the capacitor C3 is the same in terms of its elemental surface (including the capacitance) and the function of the capacitor C2 in Fig. The control unit 60 controls the capacitance variable unit 50a to control the on / off state of the capacitor switch SW2.

The control unit 60 controls the above-described capacitance variable portion 50a to vary the total capacitance of the linear motor 10 to vary the operating frequency due to the variable capacitance and the coil winding body L, The output of the compressor, that is, the cooling power, can be changed. In particular, the output of the linear compressor must vary in size depending on the load, but the output of the linear compressor may be increased or decreased regardless of the magnitude of the load. The control of the control unit 60 for such output change and inrush current prevention will be described with reference to FIGS. 5 and 6 below.

5 is a flow chart of the first embodiment of the control method for the control apparatus of Figs. 3 and 4. Fig. At the beginning of this flowchart, the controller 60 closes the on-off switches SW1 and 40 so that the power is applied to the coil winding body L and the capacitor C1 so that the linear compressor generates a predetermined output .

In step S51, the control unit 60 determines whether the linear compressor should generate additional cooling power. This determination may be required, depending on the load or irrespective of the load, as described above, and it may be appropriate for each case. If the cooling power is required (i.e., in the case of high cooling power control), the process proceeds to step S52; otherwise, it is determined that high cooling power control is not required, that the low cooling power control is maintained, The control is ended and the control is changed to the low cooling power control), the process proceeds to step S55.

In step S52, the control unit 60 turns off (i.e., opens) the on-off switch SW1. Here, the controller 60 maintains the off state for a predetermined time (for example, several seconds), so that the charge charged in the capacitor C1 can be consumed to some extent.

In step S53, the control unit 60 controls the capacitance variable units 50 and 50a, that is, the capacitor switch SW2 is turned on, that is, closed. Here, the control unit 60 maintains the on state (SW1 is off and SW2 is on) so that almost all of the charges charged in the capacitor C1 can be consumed. This consumption is made by the inrush current prevention element 52 or a coil of the coil winding body L. [

In step S54, the controller 60 turns on the capacitor C1 and the capacitance variable parts 50 and 50a (that is, the capacitors C2 and C3) by turning on the on-off switch SW1 ), I.e., the total capacitance is increased more than before, so that the high-cooling operation is performed.

In step S55, the control unit 60 determines whether the current capacitor switch SW2 is in an on-state, that is, closed. If the capacitor switch SW2 is in the on-state (current high-cooling operation state), the process proceeds to step S56. Otherwise, the current low-cooling operation is maintained.

In step S57, the control unit 60 turns off the on-off switch SW1. This off-time is maintained as in step S52 for a predetermined time. When the controller 60 performs the step S58 without performing the step S57, the rush current due to the charges charged in the capacitors C2 and C3 flows to the on-off switch SW1, The step S57 is required.

In step S58, the controller 60 opens the capacitor switch SW2 by turning it off. The control unit 60 causes the electric charges charged in the capacitors C1 and / or C2 and C3, particularly the charges charged in the capacitors C2 and C3, to be maintained for a predetermined period of time To be consumed.

In step S59, the controller 60 turns on the on-off switch SW1 so that the power source is applied through the capacitor C1 and the coil winding body L, that is, the total capacitance is lower than before, Let the operation take place.

In the control method according to the first embodiment described above, the controller 60 controls the ON / OFF switches SW1 and SW40 to be turned off before the total capacitance is changed through the control of the capacitor variable units 50 and 50a , It is possible to prevent an additional inrush current in addition to the inrush current prevention according to the configurations of FIGS.

Fig. 6 is a flowchart of a second embodiment of the control method for the control apparatus of Figs. 3 and 4. Fig.

In step S61, the controller 60 determines whether to stop the operation of the linear compressor performing the current high-cooling operation or low-cooling operation. Such interruption may be made in accordance with an instruction from a device equipped with this linear compressor, or when it is determined that sufficient cooling power is maintained and further cooling power is not required. If the operation of the linear compressor is to be stopped, the process proceeds to step S62. Otherwise, if the current operation is maintained, the process is terminated.

In step S62, the controller 60 turns off the on-off switches SW1 and 40 so that the power is no longer applied to the coil winding body L and the capacitor C1 and / or the capacitors C2 and C3 And the charge of the capacitor C1 and / or the capacitors C2 and C3 is consumed. Off state of the on-off switch (SW1) 40 can be maintained for a predetermined time.

In step S63, the controller 60 determines whether the capacitor switch SW2 is in the ON state. If the capacitor switch SW2 is in the ON state (the current high-cooling operation mode), the control unit 60 proceeds to step S64, ).

In step S64, the control unit 60 turns off the capacitor switch SW2 so that the charges of the capacitors C2, C3 and / or the capacitor C1 are consumed.

As described above, even when the operation of the linear compressor is stopped, the control unit 60 preferentially turns off the on-off switches SW1 and 40, then turns off the capacitor switch SW2, Breakage of the switch SW2 or SW1 due to the inrush current can be prevented.

The present invention having such a configuration has an effect of preventing an inrush current by controlling the output by varying the capacitance of the entire control device.

In addition, the present invention also has an effect of more effectively preventing the inrush current by performing control on the on-off switch of the linear compressor when the capacitance is variable.

Further, the present invention has an effect of effectively preventing the inrush current by controlling the on or off sequence of these switches in a linear motor or a control apparatus having a plurality of switches.

Claims (11)

delete delete A coil winding body formed in a linear compressor; A first capacitor having one end connected to the coil winding body and the other end connected to the other end of the capacitor variable portion; A capacitance variable portion having one end connected to the winding tab of the coil winding body and the other end connected to the other end of the first capacitor to prevent an inrush current; A control unit for controlling the capacitance variable unit to vary the total capacitance of the control device to induce a change in output of the linear compressor; And a power on / off switch for supplying and cutting off power from the coil winding body. 4. The control apparatus for a linear compressor according to claim 3, wherein the control unit preferentially controls the power on / off switch to control the capacitance variable unit to cut off the power. 4. The apparatus of claim 3, wherein the capacitance variable unit comprises at least one second capacitor, and a capacitor switch for controlling the current flow between the second capacitor and the winding tab, wherein the control unit controls the power on / And controls the capacitor switch to cut off the current flow. A coil winding body formed in a linear compressor; A first capacitor connected in series to the coil winding; A capacitance variable section connected in parallel to the first capacitor, the capacitance variable section including at least one second capacitor, a rush current prevention element, and a capacitor switch for controlling current flow between the second capacitor and the rush current prevention element; A power on / off switch for supplying and cutting off power by a coil winding body; And a control unit controlling the power on / off switch and the capacitance variable unit to vary the total capacitance of the control unit to induce a change in output of the linear compressor. The control device for a linear compressor according to claim 6, wherein the control unit controls the capacitor switch. 7. The control apparatus for a linear compressor according to claim 6, wherein the inrush current prevention element includes at least one of a resistor, a negative temperature coefficient (NTC) element, and an inductor. delete 7. The control apparatus for a linear compressor according to claim 6, wherein the control unit controls the power on / off switch to control the capacitance variable unit to cut off the power supply. 7. The control apparatus for a linear compressor according to claim 6, wherein the control unit controls the power on / off switch to cut off the power, and then controls the capacitor switch to cut off the current flow.

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