KR101299548B1 - Apparatus for controlling compressor and method of the same - Google Patents

Abstract

Embodiments of the present invention expand the cooling power by performing the frequency or the amount of sliding control in accordance with the required cooling power. In addition, the embodiments of the present invention include a plurality of operation modes according to the required cooling power, and performs the stroke control, the frequency control, or the amount of sliding control according to the operation mode to operate the compressor by expanding the cooling power without any additional configuration. Embodiments of the present invention detect the load and increase the frequency, change the position of the piston, or change the frequency and the position of the piston at the same time based on the cooling force according to the load variation.

Description

Compressor control device and control method {APPARATUS FOR CONTROLLING COMPRESSOR AND METHOD OF THE SAME}

The present invention relates to a compressor control device and a control method for operating a compressor by varying the control method according to the required cooling power.

Generally, a compressor is a device that converts mechanical energy into compressed energy of a compressive fluid and is used as part of a refrigeration system, such as a refrigerator or an air conditioner.

The compressor is largely provided with a reciprocating compressor (Reciprocating Compressor) for compressing the refrigerant while the piston reciprocating linearly inside the cylinder to form a compression space between the piston (Piston) and the cylinder (Cylinder) is intake or discharge A rotary compressor and an orbiting scroll for compressing the refrigerant while the roller is eccentrically rotated along the inner wall of the cylinder to form a compression space in which the working gas is sucked or discharged between the eccentrically rotating roller and the cylinder. A scroll compressor is formed between the scroll and the fixed scroll to form a compressed space through which the working gas is sucked or discharged so that the scroll scroll rotates along the fixed scroll to compress the refrigerant.

The reciprocating compressor sucks, compresses and discharges refrigerant gas by linearly reciprocating the inner piston inside the cylinder. The reciprocating compressor is classified into a Recipro method and a Linear method according to a method of driving a piston.

The recipe is a method of coupling a crankshaft to a rotating motor and coupling a piston to the crankshaft to convert the rotational motion of the motor into a linear reciprocating motion. On the other hand, the linear method is a method of reciprocating the piston by the linear motion of the motor by connecting the piston to the mover of the linear motor.

Such a reciprocating compressor is composed of an electric unit generating a driving force, and a compression unit receiving the driving force from the electric unit to compress the fluid. As the electric unit, a motor is generally used a lot, and in the case of the linear method, a linear motor is used.

The linear motor does not require a mechanical conversion device because the motor itself directly generates a linear driving force, and the structure is not complicated. In addition, the linear motor has a characteristic of reducing the loss due to energy conversion and greatly reducing noise because there is no connection site where friction and wear occur. When the linear reciprocating compressor, hereinafter referred to as a linear compressor, is used in a refrigerator or an air conditioner, the compression ratio is changed by changing the stroke voltage applied to the linear compressor. It can be used for variable control of freezing capacity.

On the other hand, the reciprocating compressor, especially the linear compressor, reciprocates in a state in which the piston is not mechanically constrained in the cylinder, so that the piston hits the cylinder wall or the load is suddenly excessively loaded. The piston may not move forward and compression may not be performed properly. Therefore, a control device for controlling the movement of the piston with respect to the load variation or the voltage variation is essential.

Embodiments of the present invention provide a compressor control apparatus and a control method for expanding the cooling power by performing the frequency or the amount of sliding control in accordance with the required cooling power.

Embodiments of the present invention provide a compressor control apparatus and a control method for expanding the cooling power by performing the frequency control or the amount of sliding control or the frequency and the amount of sliding control when the cooling force needs to be expanded in operating the compressor in a sensorless control method. to provide.

Embodiments of the present invention provide a compressor control apparatus and a control method for detecting a load and increasing the frequency, changing the position of the piston, or simultaneously changing the frequency and the position of the piston based on the cooling force according to the load variation. .

Compressor control apparatus according to an embodiment, changing the operating frequency of the compressor motor, the center position of the piston provided in the compressor motor based on the required cooling force according to the load variation, or the operating frequency and the piston Change the center position at the same time.

Compressor control apparatus according to an embodiment, the load detection unit for detecting the magnitude of the load on the compressor motor, and determines the compressor operation mode according to the load, and according to the compressor operation mode of the operating frequency or the piston And a control unit for changing the center position or the operating frequency and the center position of the piston.

According to another embodiment of the present invention, a current detection unit for detecting a motor current applied to a compressor motor, a voltage detection unit for detecting a motor voltage applied to the compressor motor, and calculating the stroke using the motor current and the motor voltage. A stroke calculating unit, a phase difference detecting unit detecting a phase difference between a motor current applied to the compressor motor, and a stroke of the piston, and changing an operating frequency of the compressor motor in accordance with a required cooling force or in the compressor motor. And a control unit for changing the center position of the piston or simultaneously changing the operating frequency and the center position of the piston.

The compressor control apparatus according to the embodiments may further include a frequency detection unit that detects an operating frequency of the compressor motor. The compressor control device may further include a sliding amount detecting unit that detects a sliding amount of the center position of the piston moved from the initial position by using the initial position of the piston and the stroke.

Compressor control method according to an embodiment, the current detection step of detecting the motor current applied to the compressor motor, the voltage detection step of detecting the motor voltage applied to the compressor motor, using the motor current and the motor voltage And a compressor operation step of operating the compressor based on the calculated stroke and stroke command value. Here, the compressor operation step, the operation frequency of the compressor motor or the amount of sliding of the piston provided in the compressor motor in accordance with the required cooling power.

Compressor control method according to another embodiment further comprises a load detection step of detecting the size of the load on the compressor motor.

Embodiments of the present invention can expand the cooling power by performing the frequency or the amount of sliding control in accordance with the required cooling power.

Embodiments of the present invention may include a plurality of operation modes according to the required cooling power, and can operate the compressor by expanding the cooling power without any additional configuration by performing stroke control, frequency control, or sliding amount control according to the operation mode.

Embodiments of the present invention can detect a load and increase the frequency, change the position of the piston, or change the frequency and the position of the piston at the same time based on the cooling force according to the load variation.

Embodiments of the present invention can operate the compressor with a high operating efficiency in a section by changing the operation mode in a high efficiency, while operating a compressor according to the section requiring a large cooling force.

1 and 2 schematically show the configuration of a compressor control apparatus according to one embodiment;
3 and 4 schematically show the configuration of a compressor control apparatus according to another embodiment;
Figure 5 is a graph for explaining the operating efficiency according to the cooling force in embodiments of the present invention;
6 is a view for explaining a plurality of driving modes according to embodiments of the present disclosure;
7 is a view for explaining a sliding amount control according to embodiments of the present invention;
8 is a flowchart schematically illustrating a compressor control method according to an embodiment of the present disclosure;
9 is a flowchart schematically illustrating a compressor control method according to another embodiment.

Embodiments of the present invention relate to a compressor control device that controls the stroke, voltage or frequency of a compressor motor.

First, the configuration of a reciprocating compressor, in particular a linear compressor, to which a compressor control device according to embodiments of the present invention is applied, will be briefly described. However, the following configuration of the linear compressor, if necessary, some of the components may be changed or deleted, or other components may be added.

The linear compressor is provided with an inlet tube and an outlet tube through which refrigerant enters and exits on one side of the sealed container, and a cylinder is fixed inside the sealed container. In order to compress the refrigerant sucked into the compression space inside the cylinder, a piston is installed inside the cylinder to enable reciprocating linear motion. In addition, springs are provided in the direction of movement of the piston and are supported by elastic force. The piston is also connected to a linear motor that generates a linear reciprocating drive force, which controls the stroke of the piston so that the compression capacity is changed. An intake valve is installed at one end of the piston in contact with the compression space, and a discharge valve assembly is installed at one end of the cylinder in contact with the compression space. Here, the suction valve and the discharge valve assembly are automatically adjusted to open and close according to the pressure inside the compression space. The sealed container is sealed by the upper and lower shells coupled to each other, and an inlet tube through which the refrigerant is introduced and an outlet tube through which the refrigerant is discharged are installed at one side thereof. The piston is elastically supported in the movement direction so as to reciprocate linearly inside the cylinder, and the linear motors are assembled to each other by a frame to constitute the assembly outside the cylinder. This assembly is elastically supported on the inner bottom surface of the hermetically sealed container by a support spring. A predetermined oil is present on the inner bottom surface of the sealed container. An oil supply device for pumping oil is installed at a lower end of the assembly, and an oil supply pipe for supplying oil between the piston and the cylinder is formed in the lower frame of the assembly. The oil supply device is operated by the vibration generated by the reciprocating linear motion of the piston to pump oil. This oil is supplied to the gap between the piston and the cylinder along the oil supply pipe for cooling and lubrication.

The cylinder is formed by a hollow phenomenon so that the piston reciprocates linearly, and a compression space is formed at one side, and one end is located close to the inside of the inflow pipe and is installed on the same straight line as the inflow pipe. Of course, the cylinder is installed in one end close to the inlet pipe to enable the reciprocating linear motion, and the discharge valve assembly is installed on one end of the opposite side to the inlet pipe. The discharge valve assembly is a discharge cover for forming a predetermined discharge space of the cylinder, a discharge valve for opening and closing one end of the compression space side of the cylinder, and a kind of coil spring for applying an elastic force in the axial direction between the discharge cover and the discharge valve. Consists of a valve spring. At this time, the one end of the cylinder is provided with an O-ring discharge valve is in close contact with the end of the cylinder. A bent loop pipe is installed between one side of the discharge cover and the outlet pipe. The loop pipe guides the compressed refrigerant to be discharged to the outside, and buffers vibration transmitted by the interaction of the cylinder, the piston, and the linear motor to the entire sealed container. A refrigerant passage is formed in the piston to allow the refrigerant flowing from the inlet pipe to flow. One end close to the inlet pipe is installed to be directly connected to the linear motor by a connecting member, and an inlet valve is installed at one end of the opposite side to the inlet pipe, and is installed to be elastically supported by various springs in the direction of movement of the piston. In this case, the suction valve is formed in a thin plate shape with the center portion partially cut to open and close the refrigerant flow path of the piston, and one side is fixed by a screw to one end of the piston.

As the piston reciprocates linearly inside the cylinder, when the pressure in the compression space becomes lower than or equal to a predetermined suction pressure lower than the discharge pressure, the suction valve is opened to suck the refrigerant into the compression space, and the pressure in the compression space is predetermined. When the suction pressure is higher than the suction pressure, the refrigerant in the compression space is compressed while the suction valve is closed.

The linear motor is configured such that a plurality of laminations are laminated in the circumferential direction, and an inner stator is installed to be fixed to the outside of the cylinder by a frame, and a plurality of laminations are circumferentially around the coil winding body configured to wind the coils. It is configured to be laminated in the direction so that the outer stator (Outer Stator) is installed at a predetermined gap with the inner stator outside the cylinder by the frame, and located in the gap between the inner stator and the outer stator to be connected by the piston and the connecting member It consists of permanent magnets installed. Here, the coil winding may be fixed to the outer side of the inner stator. As the current is applied to the coil winding in the linear motor, electromagnetic force is generated, and the permanent magnet reciprocates linearly by the interaction of the generated electromagnetic force and the permanent magnet, and the piston connected to the permanent magnet reciprocates linearly in the cylinder. Done.

1 and 2, the compressor control apparatus according to an embodiment may change an operating frequency of a compressor motor or change a center position of a piston provided in the compressor motor based on a required cooling force according to a load change. Or simultaneously change the operating frequency and the center position of the piston.

Referring to FIG. 1, a compressor control apparatus according to an embodiment includes a load detection unit 100 and a control unit 200. The load detection unit 100 detects the magnitude of the load on the compressor motor. The control unit 200 determines the compressor operation mode according to the load. The control unit also changes the operating frequency or the center position of the piston or the operating frequency and the center position of the piston in accordance with the compressor operation mode.

Referring to FIG. 2, the compressor control apparatus further includes a current detection unit 610 for detecting a motor current applied to the compressor motor, and a voltage detection unit 620 for detecting a motor voltage applied to the compressor motor. It is composed.

The current detection unit 610 detects a drive current applied to the compressor according to the load of the compressor or the load of the refrigeration system. The current detection unit detects a motor current applied to the compressor motor. The voltage detection unit 620 detects a driving voltage applied to the compressor. The voltage detection unit detects a motor voltage applied between both ends of the compressor motor according to the load of the compressor.

The compressor control device further includes a stroke calculating unit 630 that calculates a stroke of the compressor using the compressor motor current and the compressor motor voltage. The relationship between the motor voltage, the motor current and the stroke is as follows. The stroke calculation unit 630 may calculate a stroke using the following equation based on the motor voltage detected through the voltage detection unit 620 and the motor current detected through the current detection unit 610, respectively.

Where x is the stroke, α is the motor constant, Vm is the motor voltage, R is the resistance, L is the inductance, and i is the motor current.

The control unit 200 receives a stroke command value xref and compares the stroke estimate value x calculated by the stroke calculation unit 630 with the stroke command value. The control unit compares the stroke estimate value and the stroke command value and generates a control signal in accordance with the comparison result. Here, the control signal is generally a PWM signal for controlling the PWM (Pulse Width Modulation) voltage duty for the switching elements of the inverter, or the triac.

Referring to FIG. 2, the compressor control device may further include a frequency detection unit 400 that detects an operating frequency of the compressor motor. In this case, the control unit 200 performs frequency control on the compressor using the frequency command value fref and the detected operating frequency f. The compressor control device may further include a push amount detecting unit 500 that detects a push amount in which the center position of the piston is moved from the initial position using the initial position and the stroke of the piston. In this case, the control unit 200 performs the rolling amount control using the rolling amount command value dref and the detected rolling amount. Here, the push amount represents the displacement of the center position from the initial position of the piston. The amount of sliding may be detected by subtracting the initial position of the piston from (stroke / 2). As shown in Fig. 7, the amount of sliding also increases as the load increases.

The load detection unit 100 detects the size of the compressor load, that is, the load on the compressor motor. The magnitude of the compressor load may be detected using, for example, the phase difference between the motor current and the stroke estimate and the phase difference between the motor voltage and the stroke estimate. In addition, the magnitude of the compressor load can be detected using the gas spring constant K _g . The magnitude of the compressor load can be detected using another gas damping constant (C _g ) as another example.

Referring to FIG. 3, a compressor control apparatus according to another embodiment may include a current detection unit 610, a voltage detection unit 620, a stroke calculation unit 630, a phase difference detection unit 110, and a control unit. And 200.

The current detection unit 610 detects a motor current applied to the compressor motor, and the voltage detection unit 620 detects a motor voltage applied to the compressor motor. The stroke calculating unit 630 calculates the stroke using the motor current and the motor voltage. The stroke may be calculated and detected through Equation 1. The phase difference detecting unit 110 detects a phase difference between the motor current applied to the compressor motor and the stroke of the piston.

The control unit 200 changes the operating frequency of the compressor motor, changes the center position of the piston provided in the compressor motor, or simultaneously changes the operating frequency and the center position of the piston according to the required cooling force. The control unit 200 may directly receive the required cooling power or calculate the required cooling power based on the phase difference detected by the phase difference detection unit 110. In addition, as described below, the control unit 200 may calculate the required cooling force based on the gas spring constant or the gas damping constant.

Referring to FIG. 4, the compressor control device may further include a gas spring constant calculating unit 120 that calculates a gas spring constant based on the motor current, the stroke, and the phase difference. As another example, the compressor control apparatus may further include a gas damping constant calculating unit (not shown) that calculates a gas damping constant based on the motor current, the stroke, and the phase difference.

The piston in the compressor is provided with various springs to be elastically supported in the direction of movement even if the piston in the reciprocating linear motion. Specifically, a coil spring, which is a kind of mechanical spring, is installed to elastically support the sealed container and the cylinder in the direction of movement of the piston. In addition, the refrigerant sucked into the compression space also acts as a gas spring. At this time, the coil spring has a constant mechanical spring constant (Km), and the gas spring has a gas spring constant (Kg) that varies with load. The natural frequency f n of the compressor is determined in consideration of the mechanical spring constant Km and the gas spring constant Kg. The relationship between the natural frequency (fn) and the mechanical and gas spring constants (Km, Kg) is as follows.

Where fn is the natural frequency of the piston, Km is the mechanical spring constant, Kg is the gas spring constant, and M is the mass of the piston.

The gas spring constant may be calculated as shown below based on the motor current and the stroke estimate.

Where α is the motor constant, ω is the operating frequency, Km is the mechanical spring constant, Kg is the gas spring constant, M is the mass of the piston, | I (jω) | is one cycle current peak value, and | X (jω) Represents one cycle stroke peak value.

The magnitude of the compressor load can be detected using another gas damping constant (C _g ) as another example. The gas damping constant C _g may be calculated using the phase difference between the stroke estimate and the motor current (voltage) as shown in the following equation.

Where α is a motor constant, ω is an operating frequency, Cg is a gas damping constant, | I (jω) | is one cycle current peak value, and | X (jω) | is one cycle stroke peak value.

Referring to FIG. 4, the compressor control device may further include a frequency detection unit 400 that detects an operating frequency of the compressor motor. In this case, the control unit 200 performs frequency control on the compressor using the frequency command value fref and the detected operating frequency f. The compressor control device may further include a push amount detecting unit 500 that detects a push amount in which the center position of the piston is moved from the initial position using the initial position and the stroke of the piston. In this case, the control unit 200 performs the rolling amount control using the rolling amount command value dref and the detected rolling amount. Here, the push amount represents the displacement of the center position from the initial position of the piston. The amount of sliding may be detected by subtracting the initial position of the piston from (stroke / 2). As shown in Fig. 7, the amount of sliding also increases as the load increases.

Hereinafter, the operation of the compressor control apparatus according to the embodiments will be described with reference to FIGS. 5 and 6. 5 is a graph showing the efficiency according to the cooling force, Figure 6 is a view showing a change in stroke according to the compressor operation mode.

First, referring to FIG. 6, the compressor operation mode may be divided into four operation modes according to required cooling power. The required cooling power increases from run mode 1 to run mode 4. The compressor operating modes may be stored in advance in the storage unit 210. The control unit 200 may operate the compressor by selecting one of the compressor operation modes according to the required cooling power. For example, the control unit 200 presets one or more reference cooling forces, and selects one operation mode among the compressor operation modes by comparing the required cooling force with the one or more reference cooling forces.

If the required cooling force is smaller than the first reference cooling force, the control unit 200 operates the compressor at a constant stroke (stroke = small) as in the operation mode 1. In this case, the stroke command value becomes small. If the required cooling force is equal to or greater than the first reference cooling force, the control unit 200 operates the compressor at full stroke. In this case, as shown in FIG. 6, the control unit 200 operates the compressor in the operation mode 2. For example, the control unit 200 detects the top dead center by using the phase difference between the motor current and the stroke estimate, and operates the compressor at the maximum stroke considering the position of the piston at the top dead center. As shown in Fig. 5, when the cooling force is 60 to 100%, it is better to maintain efficiency by controlling only the stroke.

The control unit 200 operates the compressor by increasing the operating frequency or increasing the amount of the rolling when the required cooling force is equal to or greater than the second reference cooling force that is larger than the first reference cooling force. For example, 110% of cooling power is required. In this case, as shown in FIG. 6, the control unit 200 operates the compressor in the operation mode 3. For example, the control unit 200 detects an operating frequency and increases the frequency command value so that the detected operating frequency increases. For example, if the compressor is currently operating at the resonant frequency, the control unit increases the operating frequency above the resonant frequency. That is, when the compressor is operated at 60 Hz, the operating frequency is increased to 61 to 65 Hz.

As another example, the control unit 200 allows the compressor capacity to be increased by increasing the amount of sliding, as shown in FIG. For example, the control unit 200 increases the amount of sliding by applying a direct current voltage or direct current so as to have a desired cooling power (capacity) without collision of the piston.

The control unit 200 operates the compressor by increasing the operating frequency and increasing the amount of rolling when the required cooling force is equal to or greater than the third reference cooling force larger than the second reference cooling force. For example, 120% of cold power is required. That is, the control unit 200 increases the driving amount by increasing the operating frequency and at the same time increasing the DC voltage. In this case, as shown in FIG. 6, the control unit 200 operates the compressor in the operation mode 4.

Referring to FIG. 8, the compressor control method according to an embodiment may include: a current detection step S110 for detecting a motor current applied to a compressor motor, and a voltage detection step S120 for detecting a motor voltage applied to the compressor motor. ), A stroke calculation step (S130) of calculating the stroke using the motor current and the motor voltage, and a compressor operation step of driving the compressor based on the calculated stroke and stroke command value. Here, the compressor operation step, the operation frequency of the compressor motor or the amount of sliding of the piston provided in the compressor motor in accordance with the required cooling power.

Referring to FIG. 9, a compressor control method according to another embodiment includes a current detection step S210, a voltage detection step S220, a stroke calculation step S230, and a compressor operation step. In addition, the compressor control method further comprises a load detection step (S240) of detecting the magnitude of the load on the compressor motor. The magnitude of the compressor load may be detected using, for example, the phase difference between the motor current and the stroke estimate and the phase difference between the motor voltage and the stroke estimate. In addition, the magnitude of the compressor load can be detected using the gas spring constant K _g . The magnitude of the compressor load can be detected using another gas damping constant (C _g ) as another example. In addition, the compressor control method presets at least one compressor operation mode (S10).

The compressor control apparatus detects a motor current applied to the compressor motor (S110, S210), and detects a motor voltage applied to the compressor motor (S120, S220). In addition, the compressor control apparatus calculates a stroke using the motor current and the motor voltage (S130, S230). The stroke may be calculated and detected through Equation 1.

5 is a graph showing the efficiency according to the cooling force, Figure 6 is a view showing a change in stroke according to the compressor operation mode. First, referring to FIG. 6, the compressor control apparatus sets one or more compressor operation modes (eg, operation modes 1 to 4) according to required cooling power (S10). The required cooling power increases from run mode 1 to run mode 4. As illustrated in FIG. 8, the compressor control apparatus may preset one or more reference cooling forces, and operate the compressor by comparing the required cooling forces with the one or more reference cooling forces. In addition, as shown in FIG. 9, the compressor control apparatus may operate the compressor by selecting one operation mode among the compressor operation modes according to the required cooling power.

If the required cooling power is less than the first reference cooling power, the compressor control device operates the compressor with a constant stroke (stroke = small) as in the operation mode 1 (S141, S251). In this case, the stroke command value becomes small. If the required cooling force is equal to or greater than the first reference cooling force, the compressor control device operates the compressor at a maximum stroke (S151). In this case, as shown in FIG. 6, the compressor control device operates the compressor in the operation mode 2 (S261). For example, the compressor control device detects the top dead center by using the phase difference between the motor current and the stroke estimate, and operates the compressor at the maximum stroke considering the position of the piston at the top dead center. As shown in Fig. 5, when the cooling force is 60 to 100%, it is better to maintain efficiency by controlling only the stroke.

The compressor controller operates the compressor by increasing the operating frequency or increasing the amount of sliding when the required cooling force is greater than or equal to the second reference cooling force greater than the first reference cooling force (S161). For example, 110% of cooling power is required. In this case, as shown in FIG. 6, the compressor control device operates the compressor in the operation mode 3 (S271). As an example, the compressor control device detects an operating frequency and increases the frequency command value so that the detected operating frequency increases. For example, if the compressor is currently operating at the resonant frequency, the control unit increases the operating frequency above the resonant frequency. That is, when the compressor is operated at 60 Hz, the operating frequency is increased to 61 to 65 Hz.

As another example, the compressor control device, as shown in FIG. 7, allows the compressor capacity to be increased by increasing the amount of sliding. For example, the compressor control device increases the amount of sliding by applying a direct current voltage or direct current so as to have a desired cooling power (capacity) without collision of the piston.

If the required cooling force is equal to or greater than the third reference cooling force greater than the second reference cooling force, the compressor control apparatus increases the operating frequency, increases the amount of sliding, and operates the compressor (S171). For example, 120% of cold power is required. That is, the compressor control device increases the driving frequency and at the same time increases the DC voltage to increase the amount of sliding. In this case, as shown in FIG. 6, the compressor control device operates the compressor in the operation mode 4 (S281).

As described above, embodiments of the present invention expand the cooling power by performing the frequency or the amount of sliding control according to the required cooling power. In addition, the embodiments of the present invention include a plurality of operation modes according to the required cooling power, and performs the stroke control, the frequency control, or the amount of sliding control according to the operation mode to operate the compressor by expanding the cooling power without any additional configuration. Embodiments of the present invention detect the load and increase the frequency, change the position of the piston, or change the frequency and the position of the piston at the same time based on the cooling force according to the load variation.

100: load detection unit 110: phase difference detection unit
120: gas spring constant calculation unit 200: control unit
210: storage unit 300: compressor
400: frequency detection unit 500: rolling amount detection unit
610: current detection unit 620: voltage detection unit
630: stroke calculation unit

Claims (22)

A load detection unit for detecting the magnitude of the load on the compressor motor; And
The compressor operation mode is determined based on the required cooling force according to the load variation, the operation frequency of the compressor motor is changed according to the compressor operation mode, the center position of the piston provided in the compressor motor is changed, or the operation is performed. And a control unit for simultaneously changing a frequency and a center position of the piston. delete The method according to claim 1,
And a frequency detecting unit detecting an operating frequency of the compressor motor. The method according to claim 1 or 3,
And a sliding amount detecting unit that detects a sliding amount of the center position of the piston moved from the initial position by using the initial position of the piston and the stroke of the piston. The method of claim 1, wherein the load detection unit,
And a phase difference detecting unit detecting a phase difference between a motor current applied to the compressor motor and a stroke of the piston. The method of claim 5, wherein the load detection unit,
And a gas damping constant calculating unit that calculates a gas damping constant based on the motor current, the stroke, and the phase difference. The method of claim 5, wherein the load detection unit,
And a gas spring constant calculating unit that calculates a gas spring constant based on the motor current, the stroke, and the phase difference. 8. The method according to any one of claims 5 to 7,
A current detection unit for detecting the motor current;
A voltage detection unit detecting a motor voltage applied to the compressor motor; And
And a stroke calculating unit configured to calculate the stroke by using the motor current and the motor voltage. The method according to claim 1,
And a storage unit configured to set a range of the cooling force required according to the load, and to set and store the compressor operation mode according to the set range of the cooling force. A current detecting unit detecting a motor current applied to the compressor motor;
A voltage detection unit detecting a motor voltage applied to the compressor motor;
A stroke calculating unit that calculates a stroke of a piston provided in the compressor motor by using the motor current and the motor voltage;
A phase difference detecting unit detecting a phase difference between the motor current applied to the compressor motor and the stroke; And
And a control unit for changing the operating frequency of the compressor motor, changing the central position of the piston, or simultaneously changing the operating frequency and the central position of the piston in accordance with the required cooling force. The method of claim 10,
And a gas damping constant calculating unit that calculates a gas damping constant based on the motor current, the stroke, and the phase difference. The method of claim 10,
And a gas spring constant calculating unit that calculates a gas spring constant based on the motor current, the stroke, and the phase difference. The control unit according to any one of claims 10 to 12, wherein
And a top dead center is detected based on the motor current, the stroke, and the phase difference. The method of claim 13,
And a sliding amount detecting unit configured to detect the amount of sliding of the center position of the piston from the initial position using the initial position of the piston and the stroke provided in the compressor motor. 15. The method of claim 14,
And a frequency detecting unit detecting an operating frequency of the compressor motor. The control unit according to any one of claims 10 to 12, wherein
Set one or more compressor operation modes according to the required cooling power range, change the operation frequency of the compressor motor, change the central position of the piston provided in the compressor motor based on the compressor operation mode, or the operation Compressor control device characterized in that for changing the frequency and the center position of the piston at the same time. A current detecting step of detecting a motor current applied to the compressor motor;
A voltage detecting step of detecting a motor voltage applied to the compressor motor;
A stroke calculation step of calculating a stroke of a piston provided in the compressor motor by using the motor current and the motor voltage; And
And a compressor operation step of operating the compressor based on the calculated stroke and stroke command value.
The compressor operation step,
Compressor control method, characterized in that for changing the operating frequency of the compressor motor or the amount of sliding of the piston in accordance with the required cooling power. The method of claim 17,
And a load detection step of detecting a magnitude of a load applied to the compressor motor. The method of claim 17 or 18,
And setting at least one compressor operating mode based on the required cooling power and at least one reference cooling power. 19. The method of claim 17 or 18, wherein the compressor operation step,
And when the required cooling force is equal to or greater than the first reference cooling force, the compressor is operated at the maximum stroke. The method of claim 20, wherein the compressor operation step,
And when the required cooling force is equal to or greater than the second reference cooling force that is greater than the first reference cooling force, the compressor is operated by increasing the operating frequency or increasing the amount of sliding. The method of claim 21, wherein the compressor operation step,
And if the required cooling force is equal to or greater than the third reference cooling force that is greater than the second reference cooling force, increasing the driving frequency and increasing the amount of sliding to operate the compressor.

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