Compressor control device

Abstract

A compressor control device according to one aspect of the present disclosure comprises: an inverter that drives a compressor for compressing a refrigerant; a compressor control unit for supplying a control signal to the inverter; and a detection unit for detecting state information of the compressor, wherein the compressor control unit calculates a plurality of parameters on the basis of the state information detected by the detection unit, and combines at least two parameters from among the plurality of parameters so as to determine whether the compressor operates abnormally, and thus the accuracy of compressor abnormality diagnosis can be improved.

Description

Compressor control unit

[0001] The present disclosure relates to a compressor control device, and more particularly, to a compressor control device and a diagnostic method thereof that can accurately diagnose the status of a reciprocating compressor.

[0002] A compressor is a device that generally increases the pressure by compressing a refrigerant or other various operating gases, and is widely used in refrigeration equipment such as refrigerators and air conditioners.

[0003] Compressors are broadly classified into reciprocating compressors, rotary compressors, and scroll compressors.

[0004] In a reciprocating compressor, a compression space is formed between a piston and a cylinder where the working gas is sucked in and discharged, and the piston compresses the refrigerant as it moves back and forth in a straight line inside the cylinder.

[0005] In a rotary compressor, a compression space is formed between an eccentrically rotating roller and a cylinder, where the working gas is sucked in and discharged, and the roller compresses the refrigerant as it rotates eccentrically along the inner wall of the cylinder.

[0006] In a scroll compressor, a compression space is formed between an orbiting scroll and a fixed scroll, into which a working gas is sucked and discharged, and the orbiting scroll compresses the refrigerant as it rotates along the fixed scroll.

[0007] Among them, reciprocating compressors can be classified into recipro type (recipro compressor) and linear type (linear compressor) depending on the method of driving the piston.

[0008] Specifically, the reciprocating method is a method of converting the rotational power of the rotary motor into linear reciprocating motion by connecting a crank shaft to a rotary motor and a piston to the crank shaft, whereas the linear method is a method of directly connecting a piston to the actuator of a linear motor and reciprocating the piston with the linear motion of the motor.

[0009] These reciprocating compressors consist of an electric motor that generates driving force and a compression unit that receives driving force from the electric motor and compresses the fluid. A motor is generally used as the electric motor, and in the case of the linear type, a linear motor is used.

[0010] When the above reciprocating compressor is used in a refrigerator or air conditioner, the voltage input to the reciprocating compressor can be varied to vary the compression ratio of the reciprocating compressor, thereby controlling the freezing capacity.

[0011] As mentioned above, a linear reciprocating compressor has a higher compression efficiency than a reciprocating compressor because it has less friction loss due to the absence of a crankshaft that converts rotational motion into linear motion.

[0012] When applying linear compressors to refrigeration cycles, it is necessary to diagnose abnormal and normal operation. However, while existing individual compressor and motor protection technologies have required numerous data points and sensors, accurately diagnosing the fault location has been challenging.

[0013] For example, the prior art (Korean Patent Publication No. 10-2016-0107855) predicts the suction pressure using RPM, DC current, and discharge pressure information immediately before the air conditioner compressor is turned off to determine the restart time, so it is difficult to accurately diagnose and determine the location of anomalies during operation because the discharge pressure must be known.

[0014] The purpose of the present disclosure is to provide a compressor control device and a diagnostic method thereof capable of accurately diagnosing the status of a compressor.

[0015] The purpose of the present disclosure is to provide a compressor control device and a diagnostic method thereof capable of accurately diagnosing the status of a linear compressor.

[0016] The purpose of the present disclosure is to provide a compressor control device and a diagnostic method thereof that can respond quickly and accurately in the event of a compressor abnormality.

[0017] The purpose of the present disclosure is to provide a compressor control device and a diagnostic method thereof that can distinguish and determine the location of an abnormality when an abnormality occurs in a product to which a refrigeration cycle including a compressor is applied.

[0018] In order to achieve the above or other purposes, a compressor control device according to one aspect of the present disclosure includes a compressor control unit that calculates a plurality of parameters and determines whether the compressor is operating abnormally by combining at least two parameters among the plurality of parameters.

[0019] In order to achieve the above or other purposes, a compressor control device according to one aspect of the present disclosure calculates a plurality of parameters based on voltage information and current information of the compressor, and diagnoses whether the compressor is operating abnormally based on a correlation between at least two parameters.

[0020] In order to achieve the above or other purposes, a compressor control device according to one aspect of the present disclosure includes an inverter for driving a compressor that compresses a refrigerant, a compressor control unit for supplying a control signal to the inverter, and a detection unit for detecting status information of the compressor, wherein the compressor control unit generates a plurality of parameters based on the status information detected by the detection unit, and determines whether the compressor is operating abnormally by combining at least two parameters among the plurality of parameters, thereby improving the accuracy of compressor abnormality diagnosis.

[0021] The compressor control unit may include a parameter calculation unit that calculates a plurality of parameters based on voltage information and current information of the compressor, and an abnormality diagnosis unit that diagnoses whether the compressor is operating abnormally based on a correlation between at least two parameters among the plurality of parameters calculated by the parameter calculation unit.

[0022] The above compressor control unit can diagnose whether the compressor is operating abnormally by combining two or more parameters among stroke, current, voltage, power, phase difference between current and stroke, phase difference between current and speed, phase difference between current and acceleration, gas spring, gas damping, and mechanical resonance frequency.

[0023] The compressor control unit can divide the plurality of parameters into a first group including phase difference or frequency-related parameters and a second group including the remaining parameters.

[0024] The above compressor control unit can diagnose whether the compressor is operating abnormally by combining at least one parameter of the first group and at least one parameter of the second group.

[0025] The above compressor control unit can diagnose whether the compressor is operating abnormally based on the phase difference between the current and the stroke and the combination of the current.

[0026] The above compressor control unit can diagnose whether the compressor is operating abnormally by combining the phase difference between the current and stroke and the power.

[0027] The above compressor control unit can diagnose whether the compressor is operating abnormally by combining the phase difference between the current and the stroke and the gas spring.

[0028] The above compressor control unit can distinguish between a normal operation area and an abnormal operation area based on the combined first parameter and second parameter.

[0029] The compressor control unit can diagnose whether the compressor is operating abnormally based on the areas corresponding to the values ​​of the first parameter and the second parameter.

[0030] The above abnormal operation area can be divided into multiple abnormal operation areas depending on the cause of the abnormality.

[0031] The above abnormal operation area may include an overload abnormal operation area and a low load abnormal operation area.

[0032] The above abnormal operation area may include an overload abnormal operation area, a low load abnormal operation area, and a compression failure area.

[0033] The above compressor control unit can determine the type of abnormal operation based on the values ​​of the combined first parameter and second parameter.

[0034] The above compressor control unit can generate and output an error code corresponding to the type of abnormal operation determined.

[0035] The above compressor control unit can stop the operation of the compressor when it is determined that the compressor is in an abnormal operation state.

[0036] The above detection unit can detect current information of the compressor.

[0037] The above detection unit can detect voltage information and current information of the compressor.

[0038] The above detection unit may include a pressure sensor arranged on the suction side of the compressor.

[0039] According to at least one of the embodiments of the present disclosure, the condition of the compressor can be accurately diagnosed, thereby improving product reliability.

[0040] According to at least one of the embodiments of the present disclosure, a compressor control device and a diagnostic method thereof capable of accurately diagnosing the state of a linear compressor can be provided.

[0041] According to at least one of the embodiments of the present disclosure, when a compressor malfunctions, it is possible to respond quickly and accurately, thereby improving the product lifespan and reducing parts replacement costs and maintenance costs.

[0042] According to at least one of the embodiments of the present disclosure, when a problem occurs in a product to which a refrigeration cycle including a compressor is applied, the location of the problem can be identified and determined, thereby enabling a quick and accurate response to the problem.

[0043] According to at least one of the embodiments of the present disclosure, a compressor can be stably controlled even with a small number of sensors.

[0044] Meanwhile, various other effects will be disclosed directly or implicitly in the detailed description according to the embodiments of the present invention to be described later.

[0045] FIG. 1 is a schematic diagram illustrating a refrigeration cycle according to one embodiment of the present disclosure.

[0046] FIG. 2 is a block diagram of the main configuration of a compressor control device according to an embodiment of the present disclosure.

[0047] FIG. 3 is an internal block diagram of a compressor control unit according to an embodiment of the present disclosure.

[0048] FIG. 4 and FIG. 5 are drawings for reference in the explanation of normal operation and abnormal operation determination according to an embodiment of the present disclosure.

[0049] FIG. 6 is a flowchart of a compressor control method according to an embodiment of the present disclosure.

[0050] Figure 7 is a flowchart of an abnormality diagnosis process according to one embodiment of the present disclosure.

[0051] FIGS. 8 to 10 are drawings for reference in the description of parameter operations according to embodiments of the present disclosure.

[0052] FIG. 11 is a drawing for reference in the description of abnormal diagnosis according to one embodiment of the present disclosure.

[0053] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. However, the present disclosure is not limited to these embodiments and can be modified in various forms.

[0054] In the drawings, parts that are not related to the description are omitted in order to clearly and concisely explain the present disclosure, and the same drawing reference numerals are used for the same or extremely similar parts throughout the specification.

[0055] Meanwhile, the suffixes "module" and "part" used in the following description are given solely for the convenience of writing this specification, and do not impart any particularly significant meaning or role to them. Therefore, the terms "module" and "part" may be used interchangeably.

[0056] Additionally, while terms such as "first" and "second" may be used in this specification to describe various elements, these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0057] Fig. 1 is a schematic diagram illustrating a refrigeration cycle (1) according to an embodiment of the present disclosure. Fig. 2 is a block diagram illustrating the main components of a compressor control device according to an embodiment of the present disclosure.

[0058] Referring to FIGS. 1 and 2, the refrigeration cycle (1) may include a compressor (10), a condenser (20), an expander (40), and an evaporator (30).

[0059] The compressor (10) is a device for compressing a gas such as air or refrigerant gas, and can be formed to compress the refrigerant and provide it to the condenser (20).

[0060] The condenser (20) can be formed to cool the refrigerant by exchanging heat with the high-temperature, high-pressure refrigerant discharged from the compressor (10) and passing through the condenser (20).

[0061] The expander (40) is formed with an expansion valve or microtube and can expand the refrigerant that has passed through the condenser (20).

[0062] The evaporator (30) can be formed so that heat is exchanged while the refrigerant evaporates.

[0063] The refrigeration cycle (1) can be applied to home appliances such as refrigerators and air conditioners. Below, the refrigeration cycle (1) is explained using a refrigerator as an example.

[0064] A refrigerator may include a compressor (10), a condenser (20) that condenses the refrigerant compressed in the compressor (10), a freezer evaporator (30) that receives the refrigerant condensed in the condenser (20) and evaporates it, and is disposed in a freezer (not shown), and a freezer expansion valve (40) that expands the refrigerant supplied to the freezer evaporator (30).

[0065] Meanwhile, in the drawing, it is illustrated that one evaporator is used, but it is also possible to use separate evaporators for the refrigerator and freezer.

[0066] That is, the refrigerator may further include a refrigerator evaporator (not shown) disposed in the refrigerator compartment (not shown), a three-way valve (not shown) that supplies refrigerant condensed in the condenser (20) to the refrigerator evaporator (not shown) or the freezer evaporator (30), and a refrigerator expansion valve (not shown) that expands the refrigerant supplied to the refrigerator evaporator (not shown).

[0067] Additionally, the refrigerator may further include a gas-liquid separator (not shown) in which the refrigerant passing through the evaporator (30) is separated into liquid and gas.

[0068] In addition, the refrigerator may further include a refrigerator fan (not shown) and a freezer fan (51) that suck in cold air that has passed through the freezer evaporator (30) and blow it into the refrigerator compartment (not shown) and the freezer compartment (not shown), respectively.

[0069] In addition, it may further include a compressor motor (11) that drives the compressor (10), a refrigerator fan motor (not shown) that drives the refrigerator fan (not shown) and a freezer fan motor (52) that drive the freezer fan (51).

[0070] Meanwhile, in the case where a common evaporator (30) is used in the refrigerator and freezer, a damper (not shown) may be installed between the refrigerator and freezer, and a fan (not shown) may be used to forcefully blow cold air generated from one evaporator to the freezer and refrigerator.

[0071] The compressor (10) of Fig. 1 may be driven by a motor drive device (not shown) that drives the compressor motor. The motor drive device may include an inverter.

[0072] Additionally, the refrigerator fan (not shown) or the freezer fan (51) may be driven by a motor drive device that drives the refrigerator fan motor (not shown) and the freezer fan motor (not shown), respectively.

[0073] Additionally, the refrigerator can be equipped with a heater to defrost, melt ice, or for use as a home bar.

[0074] Referring to FIG. 2, an inverter (210) can drive a compressor (10) that compresses a refrigerant used in a refrigeration cycle (1). The inverter (210) can generate an AC voltage from an input AC or DC voltage and supply it to the compressor (10). The inverter (210) can control the compressor (10) by adjusting the voltage supplied to the compressor motor (11) that provides power to the compressor (10).

[0075] The compressor control unit (100) can generate a control signal and supply it to the inverter (210). For example, the compressor control unit (100) can generate a control signal in the form of PWM (Pulse Width Modulation) and supply it to the inverter (210).

[0076] The inverter (210) can drive the compressor (10) in response to the received control signal. The inverter (210) can vary the voltage and frequency applied to the compressor (10), specifically, the compressor motor (11), according to the received control signal. Specifically, the inverter (210) controls the on / off time of the internal switching element according to the PWM control signal, so that the frequency and voltage level of the DC voltage output from the power source can be varied and applied to the compressor motor (11).

[0077] For example, the inverter (210) can vary the voltage supplied to the motor (11) of the compressor (10) and control the stroke in response to the received control signal. The compressor (10) can be controlled by a switching operation within the inverter (210).

[0078] The detection unit (230) can detect status information of the compressor (10) and / or the refrigeration cycle (1). For example, the detection unit (230) can detect voltage information of the compressor (10). In addition, the detection unit (230) can detect voltage information and current information of the compressor (10).

[0079] The detection unit (230) may include a current detection unit (not shown) that detects the current supplied to the compressor (10). The current detection unit may detect the motor current applied to the compressor motor (11). The motor current may be a current flowing in a coil of the compressor motor. The current detection unit may include a current sensor or a shunt resistor, and may detect the motor current.

[0080] In addition, the detection unit (230) may further include a voltage detection unit (not shown) that detects the voltage supplied to the compressor (10). The voltage detection unit may detect the motor voltage applied to both ends of the compressor motor (11). The voltage detection unit may include a voltage sensor (for example, a voltage differential amplifier, etc.) and may detect the motor voltage.

[0081] The detection unit (230) may include one or more sensors that detect pressure, temperature, and humidity. The detection unit (230) may include a pressure sensor disposed on the suction side of the compressor (10) and / or a pressure sensor disposed on the discharge side of the compressor (10).

[0082] According to one embodiment of the present disclosure, the compressor control unit (100) can diagnose the compressor (10) and the refrigeration cycle (1) by combining parameters calculated based on current and voltage information of the compressor motor. Accordingly, the compressor (10) and the refrigeration cycle (1) can be stably operated even if some sensors are removed. The pressure sensor is a relatively expensive sensor, and one of the pressure sensors can be removed. For example, the detection unit (230) may include a pressure sensor arranged on the suction side of the compressor (10), and may not include a pressure sensor on the discharge side.

[0083] The memory (220) can store data required for the operation of the compressor (10) and / or home appliance (e.g., refrigerator).

[0084] The home appliance control unit (300) can control the overall operation of the home appliance (e.g., refrigerator). For example, the home appliance control unit (300) can transmit a cooling capacity command value based on the load of the refrigerator to the compressor control unit (100), and the compressor control unit (100) can generate a control signal for the compressor (10) based on the received cooling capacity command value.

[0085] The compressor control unit (100) can calculate a plurality of parameters based on the status information detected by the detection unit (230). For example, the compressor control unit (100) can calculate parameters such as stroke and power based on the current and voltage information of the compressor (10) detected by the detection unit (230), more specifically, the current and voltage flowing in the compressor motor (11).

[0086] In addition, the compressor control unit (100) can calculate other parameters using the parameters corresponding to the current and voltage information obtained from the detection unit (230) and the calculated parameters. For example, the phase difference between current and stroke, the phase difference between current and velocity, the phase difference between current and acceleration, gas spring, gas damping, mechanical resonance frequency, etc. can be calculated.

[0087] Meanwhile, the compressor control unit (100) can determine whether the compressor (10) and / or the refrigeration cycle (1) is operating abnormally and its current status by combining at least two parameters among a plurality of parameters.

[0088] The compressor control unit (100) can diagnose whether the compressor (10) and / or the refrigeration cycle (1) is operating abnormally and its current status by combining two or more parameters among stroke, current, voltage, power, phase difference between current and stroke, phase difference between current and speed, phase difference between current and acceleration, gas spring, gas damping, and mechanical resonance frequency.

[0089] The compressor control unit (100) can determine normal operation and abnormal operation based on the correlation of two or more parameters among stroke, current, voltage, power, phase difference between current and stroke, phase difference between current and speed, phase difference between current and acceleration, gas spring, gas damping, and mechanical resonance frequency.

[0090] For example, the compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally by using the phase difference between the current and the stroke, and the combination of the current.

[0091] The compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally by combining the phase difference between the current and the stroke and the power.

[0092] The compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally by using the phase difference between the current and the stroke and the combination of the gas spring.

[0093] The compressor control unit (100) can divide the above-described plurality of parameters into a first group including phase difference or frequency-related parameters and a second group including the remaining parameters. For example, the phase difference between current and stroke, the phase difference between current and velocity, the phase difference between current and acceleration, mechanical resonance frequency, etc. can be classified into the first group, and current, power, gas spring, gas damping, etc. can be classified into the second group.

[0094] The compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally by combining at least one parameter from the first group and at least one parameter from the second group.

[0095] The compressor control unit (100) can determine the type of abnormal operation based on the values ​​of the combined first and second parameters.

[0096] The compressor control unit (100) can stop the operation of the compressor (10) when it is determined that the compressor (10) is in an abnormal operation state, thereby preventing safety accidents, inefficient operation, and additional damage to the compressor (10) and other components.

[0097] In addition, the compressor control unit (100) can generate an error code corresponding to the type of abnormal operation determined and output it to the appliance control unit (300). The appliance control unit (300) can display the error code on a display and transmit the error code to a server and / or a user's terminal. Accordingly, the user can know the current occurrence of an abnormality in the compressor (10) and refrigeration cycle (1) and the cause of the abnormality, and can respond quickly.

[0098] According to the present disclosure, by using two or more parameters of a compressor (10) exhibiting different characteristics, abnormal operation and normal operation can be distinguished and diagnosed, and low pressure leakage, high pressure leakage, cycle blockage, and compressor valve destruction / damage can be diagnosed to identify the specific cause of failure.

[0099] FIG. 3 is an internal block diagram of a compressor control unit according to an embodiment of the present disclosure.

[0100] Referring to FIG. 3, the compressor control unit (100) may include a parameter calculation unit (110) that calculates a plurality of parameters based on voltage information and current information of the compressor (10), and an abnormality diagnosis unit (120) that diagnoses whether the compressor (10) is operating abnormally based on a correlation between two or more parameters.

[0101] The abnormal diagnosis unit (120) can diagnose whether the compressor (10) is operating abnormally based on the correlation between at least two parameters among the plurality of parameters calculated in the parameter calculation unit (110).

[0102] Meanwhile, the parameter calculation unit (110) can generate voltage parameters and current parameters in response to the (motor) voltage and current information received from the detection unit (230). The abnormality diagnosis unit (120) can also handle voltage parameters and current parameters in the same way as other calculated parameters.

[0103] The parameter calculation unit (110) can calculate the stroke based on the (motor) voltage and current information received from the detection unit (230). In addition, the parameter calculation unit (110) can calculate the power based on the (motor) voltage and current information received from the detection unit (230).

[0104] Additionally, the parameter calculation unit (110) can calculate the phase difference between the current and the stroke by comparing the phase of the calculated stroke and the phase of the current.

[0105] Additionally, the parameter calculation unit (110) can calculate the gas spring using the phase difference between the calculated current and stroke, and other values.

[0106] The compressor control unit (100) can distinguish between a normal operation area and an abnormal operation area based on the combined first parameter and second parameter.

[0107] FIG. 4 and FIG. 5 are drawings for reference in the explanation of normal operation and abnormal operation determination according to an embodiment of the present disclosure.

[0108] Fig. 4 is a suction pressure-discharge pressure map showing the pressure distribution of the suction pressure (Ps) on the suction side and the discharge pressure (Pd) on the discharge side of the compressor (10), and indicates a normal operation area (410). The X-axis of Fig. 4 is the suction pressure (Ps) and the Y-axis is the discharge pressure (Pd).

[0109] Meanwhile, a contour map for a given parameter can be created by connecting points where power and current have the same value on the suction pressure-discharge pressure map. However, since parameters (e.g., power and current) often have similar patterns on the suction pressure and discharge pressure maps, it is difficult to diagnose overload abnormal operation, underload abnormal operation, and compressor compression failure during operation.

[0110] To improve service quality, it is necessary to distinguish between refrigeration cycle failures and compressor failures in refrigerators and air conditioners, and to do so, it is necessary to distinguish parameter characteristics.

[0111] The present disclosure distinguishes between normal operation and abnormal operation by using correlations of two or more parameters reflecting compressor characteristics to distinguish between refrigeration cycle failures and compressor failures of refrigerators and air conditioners, and specifically diagnoses the type of failure by distinguishing between overload abnormal operation, low load abnormal operation, and compressor compression failure among abnormal operations.

[0112] Figure 5 illustrates a normal operation area (510) and an abnormal operation area (520, 530) when the X-axis is the first parameter and the Y-axis is the second parameter.

[0113] The compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally and whether the refrigeration cycle (1) is abnormal based on the area corresponding to the values ​​of the first parameter and the second parameter.

[0114] The abnormal operation area (520, 530) can be divided into multiple abnormal operation areas depending on the cause of the abnormality.

[0115] For example, the abnormal operation area (520, 530) may include an overload abnormal operation area (520) and a low load abnormal operation area (530).

[0116] Alternatively, the abnormal operation area (520, 530) may include an overload abnormal operation area (520), a low load abnormal operation area (520), and a compression failure area (not shown).

[0117] By applying the diagnostic logic of the present disclosure, it is possible to distinguish between cycle abnormalities and compressor abnormalities, and to distinguish and determine low-pressure leakage, high-pressure leakage, and cycle blockage among cycle abnormalities.

[0118] For example, if a low pressure leak occurs between the suction side of the expander (40) and the compressor (10), the parameter values ​​gradually move to the overload abnormal operation area (520). The abnormal diagnosis unit (120) can determine that the parameter values ​​fall within the overload abnormal operation area (520) as overload abnormal operation. Meanwhile, if a problem occurs in the fan, it can also be determined as overload abnormal operation.

[0119] If a high-pressure leak occurs between the discharge side of the compressor (10) and the expander (40) due to reasons such as a weld break at the rear of the condenser (20), the parameter values ​​move to the low-load abnormal operation area (530). The abnormal diagnosis unit (120) can determine that the low-load abnormal operation is occurring if the parameter values ​​fall within the low-load abnormal operation area (530).

[0120] Meanwhile, if a cycle failure occurs, such as a clogging of the microtubes of the expander (40), the parameter values ​​may drop further in the low-load abnormal operation area (530).

[0121] Additionally, if a defect occurs in the compressor (10), the parameter values ​​may drop more than the cycle value.

[0122] Therefore, the abnormal diagnosis unit (120) can determine the cause of the failure based on the parameter values.

[0123] Meanwhile, although Fig. 5 intuitively illustrates a normal operation area (510) and an abnormal operation area (520, 530) on a map, the present disclosure is not limited thereto. Specifically, the compressor control unit (100) stores reference data for distinguishing each area (510, 520, 530) according to combined parameters in the memory (220) without generating a map, and can determine whether abnormal operation occurs by comparing the current parameter value with the reference data.

[0124] According to the present disclosure, by distinguishing between normal operation areas and abnormal operation areas based on parameters having different characteristics and patterns, it is possible to more clearly determine whether there is abnormal operation and also diagnose the cause of the abnormality.

[0125] According to the present disclosure, accurate diagnosis enables accurate response to failures, thereby reducing management and service costs. For example, while compressors were previously replaced even in the event of a cycle failure, the diagnostic logic of the present disclosure allows for response to cycle failures without compressor replacement.

[0126] FIG. 6 is a flowchart of a compressor control method according to an embodiment of the present disclosure, and FIG. 7 is a flowchart of an abnormality diagnosis process according to an embodiment of the present disclosure.

[0127] Referring to Fig. 6, first, the compressor (10) is operated with the stroke increasing according to the applied voltage (S610).

[0128] The detection unit (230) detects current during operation (S620). The detection unit (230) can also detect voltage during operation (S620).

[0129] Meanwhile, the parameter calculation unit (110) can estimate multiple parameters (S630). The parameter calculation unit (110) can calculate parameters based on voltage and current (S630). Here, the parameters include stroke, speed, acceleration, power, current and stroke phase difference, gas spring, gas damping, etc.

[0130] FIGS. 8 to 10 are drawings for reference in the description of parameter operations according to embodiments of the present disclosure.

[0131] Figure 8 shows the motor voltage (V) of the compressor (10) M ) and the process of calculating stroke based on current, and Fig. 9 illustrates the calculation formulas and factors for stroke and power calculation.

[0132] The parameter calculation unit (110) can calculate a stroke based on the current and voltage information detected by the detection unit (230). According to an embodiment, the stroke can be calculated based on the voltage supplied to the motor (11) of the known compressor (10) and the current detected by the detection unit (230).

[0133] The parameter calculation unit (110) can calculate the stroke (x) by applying the voltage and current of the compressor motor (11) to the first mathematical equation of FIG. 9.

[0134] In addition, the parameter calculation unit (110) can calculate power based on the current and voltage information detected by the detection unit (230). The parameter calculation unit (110) can calculate power (P) by applying the voltage and current of the compressor motor (11) to the second mathematical equation of FIG. 9.

[0135] The cooling capacity of a compressor can be defined by the distance between the bottom dead center (BDC) and top dead center (TDC) of a piston during a linear reciprocating motion. Furthermore, the cooling capacity of a compressor can also be defined by the operating frequency of the compressor motor, or by the power supplied to the compressor motor.

[0136] The compressor control unit (100) can increase the cooling capacity of the compressor if it is determined that the load of the compressor is large or the load of the compressor has increased.

[0137] In addition, the parameter calculation unit (110) can detect the phase difference by comparing the phase of the stroke and the phase of the motor current.

[0138] Figure 10 illustrates the calculation formulas for gas spring (Kg), gas damping (Cg), and natural frequency (fmc).

[0139] The gas spring (Kg) constant can be calculated based on the motor current and the calculated stroke (x). The gas spring (Kg), gas damping (Cg), and natural frequency (fmc) can be calculated based on the mechanical equations illustrated in Fig. 10.

[0140] The parameter calculation unit (110) can calculate the gas spring (Kg) and gas damping (Cg). The parameter calculation unit (110) can calculate the phase difference between the motor current applied to the compressor motor (11) and the stroke (x) of the piston. The parameter calculation unit (110) can calculate the gas spring constant (Kg) based on the motor current, the stroke, and the phase difference.

[0141] Additionally, the parameter calculation unit (110) can calculate the gas damping constant (Cg) based on the motor current, the stroke, and the phase difference.

[0142] Additionally, the parameter calculation unit (110) can calculate the natural frequency (fmc) using the calculated gas spring (Kg) and mechanical spring constant.

[0143] A linear motor operates at a predetermined driving frequency (fc) to cause a piston to reciprocate linearly with a predetermined stroke. A spring is installed so that the piston can be elastically supported in the direction of movement even when reciprocating linearly by the linear motor.

[0144] For example, a coil spring, which is a type of mechanical spring, is installed to be elastically supported on the sealed container and cylinder in the direction of movement of the piston. In addition, the refrigerant sucked into the compression space also acts as a gas spring. The coil spring has a constant mechanical spring constant (Km), and the gas spring has a gas spring constant (Kg) that varies depending on the load. Therefore, the natural frequency (fmc) of the piston (or linear compressor) is calculated by considering the mechanical spring constant (Km) and the gas spring constant (Kg). The natural frequency (fmc) of the piston is as shown in the last mathematical equation of Fig. 10.

[0145] The abnormal diagnosis unit (120) can determine the operating point by combining two or more parameters, distinguish between normal operation and abnormal operation, and diagnose the cause of abnormal operation (S640).

[0146] If the abnormal diagnosis unit (120) diagnoses an overload abnormality (S710), an underload abnormality (S720), or a compressor compression failure (S730) during abnormal operation, it generates a corresponding error code (S750).

[0147] According to an embodiment, the abnormality diagnosis unit (120) can determine an abnormality not included in overload abnormality (S710), underload abnormality (S720), and compressor compression failure (S730) as other abnormality (S740) and generate a corresponding error code (S750).

[0148] Meanwhile, in case of abnormal operation (S650), the abnormal diagnosis unit (120) can transmit the abnormal diagnosis result to the control unit (300) of the home appliance such as a refrigerator or air conditioner (S660), stop the compressor (10) (S670), and prepare to provide service according to the type of failure.

[0149] Meanwhile, if it is not an abnormal operation (S650), the compressor control unit (100) can control the compressor (10) according to the normal operation logic and monitor the status of the compressor (10) and the refrigeration cycle (1) by applying the above-described diagnostic logic (S610 to S650) (S680).

[0150] FIG. 11 is a drawing for reference in the description of abnormal diagnosis according to one embodiment of the present disclosure.

[0151] Figure 11 illustrates a normal operation area (1110) and an abnormal operation area (1120, 1130, 1140) when the X-axis is the first parameter and the Y-axis is the second parameter.

[0152] The abnormal diagnosis unit (120) can determine normal operation and abnormal operation based on the correlation between parameters such as stroke, current, voltage, current and velocity phase difference, current and acceleration phase difference, mechanical resonance frequency, gas spring, and gas spring.

[0153] For example, the first parameter may be the phase difference between the current and the stroke, and the second parameter may be the current. Alternatively, the first parameter may be the phase difference between the current and the stroke, and the second parameter may be power. Alternatively, the first parameter may be the phase difference between the current and the stroke, and the second parameter may be a gas spring.

[0154] Alternatively, as the first parameter of the X-axis, other parameters such as current and stroke phase difference, current and velocity phase difference, current and acceleration phase difference, gas spring, mechanical resonance frequency, etc. can be used, and as the second parameter of the Y-axis, other than current and power, voltage, gas damping, etc. can be used.

[0155] Meanwhile, the compressor control unit (100) can diagnose whether the compressor (10) is operating abnormally and whether the refrigeration cycle (1) is abnormal based on the area corresponding to the values ​​of the first parameter and the second parameter.

[0156] The abnormal operation area (1120, 1130, 1140) may include an overload abnormal operation area (1120), a low load abnormal operation area (1120), and a compression failure area (1130).

[0157] The abnormal diagnosis unit (120) can accurately diagnose the status of the compressor by comparing the first and second parameter values ​​(x, y) with reference data to determine which area they correspond to, thereby improving product reliability.

[0158] The abnormal diagnosis unit (120) can diagnose overload abnormal operation if the second parameter value (y) is greater than c1 and the first and second parameter values ​​(x, y) satisfy the inequality y>a1x+b1 corresponding to the boundary line (1121) of the overload abnormal operation area (1120). Here, a1, b1, and c1 may vary depending on the selected parameters.

[0159] The abnormal diagnosis unit (120) is an inequality y in which the first parameter value (x) is smaller than d1, the second parameter value (y) is larger than c2 and smaller than c3, and the first and second parameter values ​​(x, y) correspond to the boundary line (1131) of the low-load abnormal operation area (1130). <a2x+b2을 만족하면, 저부하 이상운전이라고 진단할 수 있다. 여기서, a2, b2, c2, c3, d1은 선정되는 파라미터에 따라 달라질 수 있다.

[0160] The abnormal diagnosis unit (120) can diagnose a compressor compression failure if the first parameter value (x) is less than d1 and the second parameter value (y) is greater than c2.

[0161] According to at least one of the embodiments of the present disclosure, when a problem occurs in a product to which a refrigeration cycle including a compressor is applied, the product lifespan can be improved and parts replacement costs and maintenance costs can be reduced by responding quickly and accurately.

[0162] Although the preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made by a person having ordinary skill in the art to which the present disclosure pertains without departing from the gist of the present disclosure as claimed in the claims.

Claims

1. An inverter that drives a compressor that compresses the refrigerant; A compressor control unit that supplies a control signal to the inverter; and A detection unit for detecting status information of the compressor is included; The above compressor control unit, Generate multiple parameters based on the status information detected by the above detection unit, A compressor control device that determines whether the compressor is operating abnormally by combining at least two parameters among the above plurality of parameters.

2. In paragraph 1, The above compressor control unit, A parameter calculation unit that calculates multiple parameters based on voltage information and current information of the compressor, A compressor control device including an abnormality diagnosis unit that diagnoses whether the compressor is operating abnormally based on the correlation of at least two parameters among a plurality of parameters calculated in the parameter calculation unit.

3. In paragraph 1, The above compressor control unit, A compressor control device that diagnoses whether the compressor is operating abnormally by combining two or more parameters among stroke, current, voltage, power, phase difference between current and stroke, phase difference between current and speed, phase difference between current and acceleration, gas spring, gas damping, and mechanical resonance frequency.

4. In paragraph 3, The above compressor control unit, The above plurality of parameters are divided into a first group including phase difference or frequency-related parameters and a second group including the remaining parameters, A compressor control device that diagnoses whether the compressor is operating abnormally by combining at least one parameter of the first group and at least one parameter of the second group.

5. In paragraph 3, The above compressor control unit, A compressor control device that diagnoses whether the compressor is operating abnormally based on the phase difference between the current and stroke and the combination of the current.

6. In paragraph 3, The above compressor control unit, A compressor control device that diagnoses whether the compressor is operating abnormally by combining the phase difference between the current and stroke and the power.

7. In paragraph 3, The above compressor control unit, A compressor control device that diagnoses whether the compressor is operating abnormally by combining the phase difference between the current and stroke and the gas spring.

8. In paragraph 1, The above compressor control unit, Based on the combined first and second parameters, the normal operation area and the abnormal operation area are distinguished, A compressor control device that diagnoses whether the compressor is operating abnormally based on the areas corresponding to the values ​​of the first parameter and the second parameter.

9. In paragraph 8, The above abnormal driving area is, A compressor control device that is divided into multiple abnormal operation areas depending on the cause of the abnormality.

10. In paragraph 9, The above abnormal driving area is, A compressor control device including an overload abnormal operation area and an underload abnormal operation area.

11. In paragraph 9, The above abnormal driving area is, A compressor control device including an overload abnormal operation area, an underload abnormal operation area, and a compression failure area.

12. In paragraph 1, The above compressor control unit, Based on the values ​​of the combined first and second parameters, the type of abnormal driving is determined, A compressor control device that generates and outputs an error code corresponding to the type of abnormal operation identified.

13. In paragraph 1, The above compressor control unit, If the above compressor is determined to be in an abnormal operating state, A compressor control device that stops the operation of the above compressor.

14. In paragraph 1, The above detection unit is a compressor control device that detects voltage information and current information of the compressor.

15. In paragraph 1, The above detection unit is a compressor control device including a pressure sensor arranged on the suction side of the compressor.

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