Compressor and control method of compressor

Abstract

The compressor and the compressor control method according to the present embodiment aim to prevent damage to the compressor and ensure stable operation by detecting the state of the suction refrigerant.

Description

Technology Field

[0001] The present invention relates to a compressor, and more specifically, to a compressor and a method for controlling the compressor that detects the state of the suction refrigerant in a compressor equipped in an eco-friendly vehicle to protect the compressor and enable stable operation. Background Technology

[0003] Generally, a brief overview of a vehicle's air conditioning system shows that the refrigerant, initially in a high-temperature, low-pressure gaseous state, is first converted into a high-temperature, high-pressure gaseous state by the compressor. This high-temperature, high-pressure gaseous refrigerant then passes through a condenser and becomes a high-temperature, high-pressure liquid state through the condensation action of the condenser. Finally, this high-temperature, high-pressure liquid refrigerant passes through an expansion valve and becomes a low-temperature, low-pressure liquid state through the throttling action of the expansion valve.

[0004] The above-mentioned low-temperature, low-pressure liquid refrigerant passes through an evaporator and returns to a high-temperature, low-pressure gaseous state through heat exchange occurring in the evaporator, and the high-temperature, low-pressure gas is then compressed by the compressor to become a high-temperature, high-pressure gaseous state. The vehicle's air conditioning system operates by repeating this process.

[0005] Compressors that perform refrigerant compression are classified into reciprocating types, which perform compression through reciprocating motion, and rotary types, which perform compression through rotational motion.

[0006] Reciprocating types include the crank type, which transmits the driving force of a drive source to multiple pistons using a crank; the swash plate type, which transmits the force using a rotating shaft equipped with a swash plate; and the wobble plate type, which uses a wobble plate.

[0007] Rotary types include vane rotary types that use a rotating rotary shaft and vanes, and scroll types that use a rotary scroll and a fixed scroll.

[0008] Among these compressors, those using an electric motor as a power source are commonly referred to as electric compressors, and among the types of compressors, swashplate compressors are widely used in automotive air conditioning systems.

[0009] The aforementioned compressor relates to a compressor installed in internal combustion engine vehicles. Recently, with the advancement of technology and the widespread adoption of infrastructure, it is being installed in eco-friendly vehicles such as pure electric vehicles, plug-in hybrids, and electric vehicles, and compressors with new drive mechanisms different from those in conventional internal combustion vehicles are being used. Prior art literature

[0011] Japanese Patent Publication No. 2019-174048 The problem to be solved

[0012] The embodiments of the present invention aim to provide a compressor and a method for controlling the compressor that can prevent damage to the compressor and improve efficiency by preventing in advance risk factors, such as insufficient cooling or insufficient lubrication, which may occur due to a lack of intake refrigerant when the compressor installed in an eco-friendly vehicle is operating. means of solving the problem

[0014] The compressor according to the present embodiment comprises: a compression unit (5) equipped with a compression means for compressing a refrigerant; a motor unit (3) coupled to the compression unit (5) and into which suction refrigerant sucked in through a suction port (22) flows, and which generates rotational power for compressing the suction refrigerant; an inverter unit (50) coupled to the outside of the motor unit (3); and a control unit (100) that determines the state of the suction refrigerant in real time, wherein the control unit (100) performs control by comparing the actual flow rate state of the suction refrigerant sucked into the motor unit (3) when the compression unit (5) is actually operated with the state when it is operated in a low flow rate state. The motor unit is equipped with a sensing unit to detect the state of the suction refrigerant. The low flow rate state is set based on the state in which the compressor operates under operating conditions of a low amount of refrigerant.

[0015] The above-mentioned sensing unit (80) includes a first sensing unit (82) for sensing the pressure of the suction refrigerant and a second sensing unit (84) for sensing the temperature of the suction refrigerant, and the low flow rate state is characterized by applying a correction density value of the suction refrigerant to the pressure of the suction refrigerant measured by the first sensing unit (82).

[0016] The above correction density value is characterized by applying a density value corresponding to 40% of the total density value corresponding to the pressure of the suction refrigerant.

[0017] The actual flow rate state of the suction refrigerant is characterized by determining that the amount of refrigerant sucked into the motor unit (3) is reduced when the pressure of the suction refrigerant is lower than the low flow rate state.

[0018] The above control unit (100) is characterized by controlling the motor unit (3) such that the rotational speed per minute (rpm) of the compression unit (5) is reduced when the suction refrigerant is at a suction pressure relatively lower than the low flow rate state.

[0019] The above control unit (100) is characterized by controlling the motor unit (3) after confirming whether the rotational speed (rpm) of the compression unit (5) is operating at the minimum rotational speed (minimum rpm) when the suction refrigerant is at a suction pressure relatively lower than the low flow rate state.

[0020] The control unit (100) controls the compressor (5) so that when the rotational speed (rpm) of the compressor (5) is maintained at the minimum rotational speed (minimum rpm), the rotational speed is fixed or after waiting for t seconds, the compressor (5) continues to operate when the suction pressure of the refrigerant is higher than the low flow rate condition, and the compressor (5) stops operating when the suction pressure of the refrigerant is lower than the low flow rate condition.

[0021] The first sensing unit (82) and the second sensing unit (84) are positioned at the shortest distance from the inverter unit (50) and are connected to each other via a wiring harness with the control unit (100).

[0022] This embodiment can be installed and used in a vehicle air conditioning system equipped with a compressor.

[0024] A control method for a compressor according to the present embodiment comprises: a first step (ST100) of determining the power status of the compressor; a second step (ST200) of detecting the pressure and temperature of the suction refrigerant sucked into the compressor; a third step (ST300) of determining whether the compressor currently corresponds to a low flow rate state after comparing the actual flow rate state of the detected suction refrigerant with a preset low flow rate state; and a fourth step (ST400) of controlling the compressor so that the actual suction pressure increases if the compressor currently corresponds to a low flow rate state.

[0025] The above third step (ST300) includes a first determination step (ST310) for determining whether the temperature of the suction refrigerant corresponds to a normal range and whether the pressure of the suction refrigerant corresponds to a normal range; and a second determination step (ST320) for determining whether the temperature of the suction refrigerant corresponds to a normal range and whether the pressure of the suction refrigerant corresponds to a pressure state relatively lower than the pressure of a low flow rate state.

[0026] The above fourth step (ST400) further includes a first rotational speed control step (ST410) that controls the rotational speed of the compressor to decrease after waiting for t seconds.

[0027] The above fourth step (ST400) further includes a second rotational speed control step (ST420) that stops the operation of the compressor if, after waiting for t seconds, the rotational speed of the compressor is lower than the rotational speed of the low flow rate state. Effects of the invention

[0029] These embodiments can determine the condition of the suction refrigerant in a compressor installed in an eco-friendly vehicle and ensure stable operation of the compressor under optimal conditions, thereby preventing failures and malfunctions in advance.

[0030] These embodiments enable enhanced safety and protection of the compressor and air conditioning system as a whole by detecting the temperature condition along with the pressure of the suction refrigerant, thereby preventing in advance the phenomenon of operation with insufficient cooling and lubrication due to a lack of suction refrigerant. Brief explanation of the drawing

[0032] FIG. 1 is a cross-sectional view of a compressor according to the present embodiment. FIG. 2 is a drawing showing the exterior of a compressor according to the present embodiment. FIG. 3 is a drawing illustrating the motor section, inverter section, and sensing section of a compressor according to the present embodiment. FIG. 4 is a drawing illustrating the motor part of a compressor according to the present embodiment. FIG. 5 is a compressor according to the present embodiment FIG. 6 is a flowchart illustrating a control method of a compressor according to the present embodiment. FIG. 7 is an operation flowchart according to the compressor control method of the present embodiment. Specific details for implementing the invention

[0033] A compressor according to the present embodiment will be described with reference to the drawings.

[0034] Furthermore, the embodiments described below are provided as examples to ensure that the concept of the invention is sufficiently conveyed to those skilled in the art. Accordingly, the invention is not limited to the embodiments described below and may be embodied in other forms. Also, in the drawings, the size and thickness of the device, etc., may be exaggerated for convenience. Throughout the specification, the same reference numerals indicate the same components.

[0035] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described in detail below together with the accompanying drawings.

[0036] However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity of description.

[0037] The terms used herein are for describing embodiments and are therefore not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprise" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0038] For reference, FIG. 1 is a cross-sectional view of a compressor according to the present embodiment, FIG. 2 is a drawing showing the exterior of a compressor according to the present embodiment, FIG. 3 is a drawing showing the motor section, inverter section, and sensing section of a compressor according to the present embodiment, and FIG. 4 is a drawing showing the motor section of a compressor according to the present embodiment.

[0040] Referring to the attached FIGS. 1 to 4, the compressor according to the present embodiment is used to ensure stable operation of the compressor under low flow rate and low lubrication conditions and to prevent damage, due to the need for protection logic resulting from the increasing complexity of the system and expansion of the operating range of eco-friendly vehicles.

[0041] For example, this embodiment uses a scroll compressor, but it can be applied to other compressors and is not limited to the compressors shown in the drawings.

[0043] The compressor according to the present embodiment includes a compression unit (5) equipped with a compression means for compressing a refrigerant, a motor unit (3) coupled to the compression unit (5) and into which suction refrigerant sucked in through a suction port (22) flows, and which generates rotational power for compressing the suction refrigerant, an inverter unit (50) coupled to the outside of the motor unit (3), and a control unit (100) that determines the state of the suction refrigerant in real time. And the control unit (100) is characterized by performing control by comparing the actual flow rate state of the suction refrigerant sucked into the motor unit (3) when the compressor unit (5) is actually operated with the state when it is operated in a low flow rate state. The low flow rate state is set based on the state in which the compressor is operated under operating conditions of a low amount of refrigerant. The control unit (100) performs control by comparing the low flow rate state set based on the state of operation under operating conditions of a low amount of refrigerant with the actual flow rate state of the suction refrigerant sucked into the motor unit (3) when the compressor unit (5) is actually operated, thereby preventing damage to the compressor under conditions where the cooling and lubrication performance of the compressor may be reduced due to the reduced amount of suction refrigerant.

[0044] delete

[0046] The above compression unit (5) is a part that compresses the refrigerant by rotating by the rotational driving force generated by the motor unit (3), and is configured to include a rotating scroll (53) and a fixed scroll (51) that is rotatably coupled to the rotating scroll (53) and compresses the refrigerant to discharge it outside the compressor (1).

[0047] The above compression unit (5) is a cylindrical body open toward the motor unit (3) and is configured to separate the refrigerant into gaseous and liquid phases through a gas-liquid separation tube (60) and discharge the compressed gaseous refrigerant through a discharge port (58) opened on one side.

[0048] The above-mentioned pivot scroll (53) has a pivot scroll wrap (59) protruding in a spiral shape so as to converge toward the center, and an eccentric axis (38) of the rotation axis (37) is coupled to the center portion of the pivot scroll wrap (59). The above-mentioned pivot scroll (53) is configured to revolve in synchronization with the rotor (41) around the rotation axis (37).

[0049] The fixed scroll (51) is configured to form a compression chamber (54) when assembled with the rotating scroll (53), and the fixed scroll wrap (61), which is curved in a spiral shape to match the scroll wrap (59) of the rotating scroll (53), is arranged to converge toward the center.

[0050] Therefore, when the rotating scroll (53) rotates, the mutually matched rotating scroll (53) and fixed scroll (51) compress the refrigerant sucked from the motor part (3) into the outer edge of the rotating and fixed scroll wraps (59, 61) by the interaction of the respective rotating and fixed scroll wraps (59, 61) into the center, and then discharge it to the compressor housing (57) through the discharge port (62) in a high-pressure state.

[0052] The motor unit (3) is coupled with the compression unit (5) and is a driving source that generates rotational power for compressing the suction refrigerant sucked in through the suction port (22), and includes a driving unit housing (30) forming the outer shape, a stator (90) fixed inside the driving unit housing (30), and a rotor (41) that rotates inside the stator (90).

[0053] The above drive unit housing (30) is formed in a cylindrical shape as a part forming the outer body of the motor unit (3), and is composed of a front housing (32) that supports the front end portion of the rotor (41) and a rear housing (31) that supports the rear end portion of the rotor (41).

[0054] The above stator (90) is an electromagnet that creates rotational driving force together with a rotor (41) mounted coaxially on the inside, and is composed of a stator core that is fixedly mounted on the inner surface of a drive unit housing (30) by means of press-fitting, etc., and a stator coil (92) wound on the stator core.

[0055] The above stator core is a hollow cylindrical member, and a through hole is formed on the central axis into which a rotor (41) is inserted.

[0056] In addition, the rotor (41) is a part that is coaxially mounted on the inside of the stator (90) and rotated, and is rotatably inserted into the through hole in the center of the stator core of the stator (90).

[0057] A rotation shaft (37) is inserted along a central axis line into the rotor (41), and a rotor core (39) is coupled to the outer surface of the rotation shaft (37). When the stator (90) is energized, the rotor (41) is driven by rotation through interaction with the stator (90) according to the driving principle of the motor, and the rotation shaft (37) is supported rotatably in the drive unit housing (30) through bearings (B1, B2).

[0059] The above control unit (100) is a part that controls the operation of the motor unit (3) and is mounted on a PCB provided inside the inverter unit (50) to be described later, and is mounted on one side of the drive unit housing (30) by a cover housing (75).

[0060] The control unit (100) is electrically connected to the terminal assembly of the stator (35) and can drive or stop the rotor (41) by energizing or demagnetizing the stator (35) through an external power supply provided through a pair of connectors (20).

[0061] A control unit (100) is supplied with external power through a pair of connectors (20), and the connectors (20) and the control unit (100) are structurally connected through a terminal block and have an intermediary member (9), and the intermediary member (9) is detachably connected to the connectors (20) by fastening means such as bolts.

[0063] The above-mentioned sensing unit (80) is coupled to the motor unit (3) and is provided to detect the state of the suction refrigerant. For example, the sensing unit (80) includes a first sensing unit (82) that detects the pressure of the suction refrigerant and a second sensing unit (84) that detects the temperature of the suction refrigerant. For example, the first sensing unit (82) uses a pressure sensor, and the second sensing unit (84) uses a temperature sensor.

[0064] The first and second sensing units (82, 84) are positioned at the shortest distance from the inverter unit (50) and are connected to each other via a wiring harness (H) with the control unit (100) so that the state of the suction refrigerant can be accurately detected.

[0065] The first and second sensing parts (82, 84) are located in a position adjacent to the suction port (22) on the inner side of the rear housing (31), and after an insertion hole (not shown) is machined to be installed in the rear housing (31), the sealing is performed through a sealing member such as a gasket (not shown) or an O-ring (not shown).

[0067] In this embodiment, the compressor can be protected by setting the compressor to a low flow rate state when operating under low refrigerant amount conditions, and then detecting the temperature and pressure of the suction refrigerant sucked into the suction port (22) when the compressor is actually operated in various environments, determining whether there is a decrease in the amount of refrigerant, and then performing rotations per minute or stopping the operation of the compressor.

[0068] For example, the above low flow rate state is selected by applying the correction density value of the suction refrigerant to the pressure of the suction refrigerant measured by the first sensing unit (82).

[0069] For example, the above correction density value is applied as a density value corresponding to 40% of the total density value corresponding to the pressure of the suction refrigerant.

[0070] The reason the standard for the low flow rate state is defined as described above is that the suction refrigerant sucked in through the suction port (22) normally maintains a sufficient amount of refrigerant for stable operation of the compressor, but the suction refrigerant sucked in at a relatively low flow rate state lacks the amount of refrigerant for stable operation of the compressor.

[0071] As such, the insufficient amount of refrigerant reduces the density corresponding to the mass of the substance per unit volume, making cooling due to friction in the compressor unfavorable and reducing the amount of oil, which may cause friction, so the above correction density (defined as 40% in this embodiment) is applied to determine the low flow rate state.

[0072] In addition, the correction density value is calculated by arithmetically determining the insufficient intake refrigerant amount based on the normal intake refrigerant amount or by simulating, and is applied and explained in this embodiment, but it may also be possible to apply an error value within a certain range. For example, the aforementioned correction density value may have an error value of ±5% and may vary depending on the specifications of various compressors.

[0074] In this embodiment, the temperature information of the suction refrigerant detected by the second detection unit (84) together with the first detection unit (82) is input as an important variable for control in the control unit (100).

[0075] The temperature of the intake refrigerant mentioned above may fluctuate for various reasons. For example, it may fluctuate due to the temperature of the engine compartment, the load condition of the compressor or the vehicle, or errors or failures occurring in the condenser and evaporator; therefore, considering all of the aforementioned reasons, it acts as an important variable for the stable operation of the compressor.

[0076] For example, the control unit (100) can determine the current intake refrigerant amount more accurately by using additional information such as the temperature information of the intake refrigerant detected by the second detection unit (84) rather than determining the flow rate status of the intake refrigerant based only on the pressure information detected by the first detection unit (82).

[0077] In this case, the accuracy of the control unit (100) is improved, and the operational stability of the compressor and the occurrence of failure are prevented in advance, thereby preventing the expensive compressor from stopping operation due to failure and protecting the compressor, so that stable operation is possible even when used for a long period of time.

[0078] As the actual flow rate of the suction refrigerant decreases when the compressor is turned ON and increases when it is turned OFF, and in seasons when the ambient temperature rises to high temperatures such as summer, the temperature of the engine room also remains high, causing pressure fluctuations, it is more advantageous to use temperature information together with pressure information rather than using pressure information alone as information for the stable operation of the compressor in terms of ensuring the stability of the compressor.

[0079] In addition, since the correction density value is used as additional judgment information, accuracy and safety are improved compared to compressor control that relies solely on existing suction refrigerant pressure information.

[0081] In this way, the present embodiment detects the actual flow rate of the suction refrigerant flowing into the motor unit (20) through the suction port (22) in real time through the detection unit (80) after the suction refrigerant is set to a low flow rate state and the refrigerant amount is insufficient.

[0082] And when the pressure of the suction refrigerant is lower than the above low flow rate state, it is determined that the amount of refrigerant sucked into the motor unit (3) has decreased.

[0084] The control unit (100) according to the present embodiment controls the motor unit (3) so that the rotational speed (rpm) of the compressor unit (5) is reduced when the suction refrigerant has a suction pressure relatively lower than the pressure preset at the low flow rate state, thereby reducing the pressure of the suction refrigerant and controlling the compressor to operate.

[0085] For example, referring to the attached FIG. 5, when the suction refrigerant is introduced through the suction port (22) at a first pressure (P1) in the pH diagram, the temperature is maintained at a first temperature (T1). For reference, the X-axis represents the enthalpy of the refrigerant, and the Y-axis represents the pressure of the refrigerant.

[0086] Since the first pressure (P1) above corresponds to a pressure relatively lower than the low flow rate pressure set in the low flow rate state, the control unit (100) controls the rotational speed per minute (rpm) to decrease, thereby performing compressor control according to the suction pressure.

[0087] In this case, if the compressor is controlled so that the suction pressure gradually rises from the first pressure (P1) to the second pressure (P2) by reducing the rotational speed per minute, the temperature also rises from the first temperature (T1) to the second temperature (T2), so the flow rate of the suction refrigerant increases simultaneously with the increase in the suction pressure, thereby ensuring stable operation of the compressor.

[0088] In this case, the amount of refrigerant capable of stably performing compression is secured in the suction refrigerant raised to the second pressure (P2), and the amount of oil for lubrication is also secured, thereby preventing normal operation of the compressor and preventing damage.

[0090] The control unit (100) controls the motor unit (3) after checking whether the rotational speed (rpm) of the compression unit (5) is operating at the minimum rotational speed (minimum rpm) when the suction refrigerant is at a suction pressure relatively lower than the low flow rate state.

[0091] The above control unit (100) does not adjust the rotational speed per minute simply because the suction pressure of the compressor has decreased, but also checks whether there is a minimum rotational speed per minute and then performs control on the motor unit (3). When the minimum rotational speed per minute changes temporarily, it is limited to event-based cases and is not used as data for controlling the motor unit (3), but is used as control data for the motor unit (3) only when it continues for a certain period of time or longer.

[0093] The above compressor is equipped with an expansion valve, and the expansion valve can maintain a state in which the compressor's rotational speed per minute is kept at a minimum when the flow of refrigerant becomes unstable at a specific location.

[0094] In this case, the control unit (100) determines whether the cause of the current compressor maintaining a low suction pressure is a problem of the actual suction refrigerant being sucked in at a low suction pressure, or a problem caused by an operating error resulting from a failure in the evaporator that maintains a minimum rotational speed per minute, and performs control.

[0096] For example, the control unit (100) controls the compressor (5) so that when the rotational speed (rpm) of the compressor (5) is maintained at the minimum rotational speed (minimum rpm), the rotational speed is fixed or after waiting for t seconds, the compressor (5) continues to operate when the suction pressure of the refrigerant is higher than the low flow rate condition, and the compressor (5) stops operating when the suction pressure of the refrigerant is lower than the low flow rate condition.

[0097] When the above control unit (100) controls in this manner, low flow rate control can be performed by considering various risk factors together with the pressure state of the suction refrigerant and whether there is an abnormality in the compressor components, thereby minimizing unnecessary friction during operation and preventing wear and noise of components due to oil shortage, thereby ensuring stable operation.

[0098] This embodiment can be applied to a vehicle air conditioning system equipped with the aforementioned compressor, and the vehicle air conditioning system may include an eco-friendly vehicle.

[0100] A method for controlling a compressor according to the present embodiment will be explained with reference to the drawings.

[0101] Referring to the attached FIGS. 6 and 7, the control method of a compressor according to the present embodiment includes a first step (ST100) of determining the power status of the compressor, a second step (ST200) of detecting the pressure and temperature of the suction refrigerant sucked into the compressor, a third step (ST300) of determining whether the compressor is currently in a low flow rate state after comparing the actual flow rate state of the detected suction refrigerant with a preset low flow rate state, and a fourth step (ST400) of controlling the compressor so that the actual suction pressure increases when the compressor is currently in a low flow rate state.

[0102] The aforementioned control unit determines whether the compressor is in an ON or OFF state (ST100) before controlling the compressor. For example, if the compressor is in an ON state, the pressure and temperature of the suction refrigerant are detected after the suction refrigerant is sucked in through the suction port.

[0103] The pressure and temperature of the suction refrigerant are detected by the aforementioned sensing unit and transmitted to the control unit through the harness in order to prevent the compressor from operating in a low flow rate state as described above (ST200).

[0105] In this embodiment, the pressure and temperature of the suction refrigerant and the pressure corresponding to the temperature of the suction refrigerant are used to determine whether the current state of the suction refrigerant corresponds to a low flow rate state (ST300).

[0106] For example, the third judgment step (ST300) includes a first judgment step (ST310) for determining whether the temperature of the suction refrigerant is within a normal range and whether the pressure of the suction refrigerant is within a normal range, and a second judgment step (ST320) for determining whether the temperature of the suction refrigerant is within a normal range and whether the pressure of the suction refrigerant is in a pressure state relatively lower than the pressure of a low flow rate state.

[0107] The above first judgment step (ST310) operates stably without insufficient flow rate or lack of lubricating oil during compressor operation because the temperature and pressure of the suction refrigerant fall within the normal range.

[0108] The second judgment step (ST310) determines that if the suction refrigerant temperature is normal but the pressure is lower than the pressure of the low flow rate state, the amount of suction refrigerant required for stable operation of the compressor is insufficient.

[0109] In this case, the control unit waits for t seconds to increase the actual suction pressure of the suction refrigerant, and then controls the compressor to decrease the rotational speed per minute so that the pressure of the suction refrigerant increases, thereby performing a first rotational speed control per minute (ST410). The t seconds is applied differently depending on the specifications of the compressor, but for example, it is selected from a time selected from 10 seconds or less than 10 seconds.

[0110] If, after waiting for t seconds, the rotational speed per minute of the compressor is lower than the rotational speed per minute of the low flow rate state, a second rotational speed control step (ST420) is performed to stop the operation of the compressor.

[0111] The second rotational speed control per minute is implemented as described above to protect the components constituting the compressor, thereby preventing additional failures and ensuring stable operation of the compressor.

[0112] In particular, considering the complex systems and diverse operating ranges of eco-friendly vehicles, the compressor can be protected from malfunction and damage.

[0114] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention. Explanation of the symbols

[0115] 3 : Motor section 5 : Compression section 22: Suction port 50: Inverter section 80 : Detector 82, 84: 1st and 2nd detection units 100 : Control unit

Claims

Claim 1 A compression unit equipped with a compression means for compressing a refrigerant; a motor unit coupled to the compression unit, into which suction refrigerant sucked in through a suction port flows, and which generates rotational power for compressing the suction refrigerant; and an inverter unit coupled to the outside of the motor unit; A compressor comprising a control unit that determines the state of the suction refrigerant in real time, wherein the control unit performs control by comparing the actual flow rate state of the suction refrigerant sucked into the motor unit when the compressor unit is actually operated with the state when it is operated in a low flow rate state, wherein the control unit performs control by comparing the low flow rate state set based on the state in which the compressor unit is operated under low refrigerant amount operating conditions with the actual flow rate state of the suction refrigerant sucked into the motor unit when the compressor unit is actually operated, wherein a sensing unit is provided in the motor unit to detect the state of the suction refrigerant, and the sensing unit includes a first sensing unit that detects the pressure of the suction refrigerant and a second sensing unit that detects the temperature of the suction refrigerant, wherein the first and second sensing units are located at a position adjacent to the suction port to detect the state of the suction refrigerant flowing into the suction port, and wherein the low flow rate state is characterized by applying a correction density value of the suction refrigerant to the pressure of the suction refrigerant measured by the first sensing unit. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A compressor according to claim 1, characterized in that the correction density value is applied as a density value corresponding to 40% of the total density value corresponding to the pressure of the suction refrigerant. Claim 6 A compressor according to claim 1, wherein the actual flow rate state of the suction refrigerant is determined to be a reduced amount of refrigerant sucked into the motor unit when the pressure of the suction refrigerant is lower than the low flow rate state. Claim 7 In claim 1, the compressor wherein the control unit controls the motor unit so that the rotational speed per minute (rpm) of the compressor unit is reduced when the suction refrigerant is at a suction pressure relatively lower than the low flow rate state. Claim 8 A compressor according to claim 1, wherein the control unit controls the motor unit after confirming whether the rotational speed (rpm) of the compressor unit is operating at a minimum rotational speed (minimum rpm) when the suction refrigerant is at a suction pressure relatively lower than the low flow rate state. Claim 9 A compressor according to claim 1, wherein the control unit controls the compressor such that when the rotational speed (rpm) of the compressor is maintained at a minimum rotational speed (minimum rpm), the rotational speed is fixed or after waiting for t seconds, the compressor continues to operate when the suction pressure of the refrigerant is higher than the low flow rate state, and the compressor stops operating when the suction pressure of the refrigerant is lower than the low flow rate condition state. Claim 10 A compressor according to claim 1, wherein the first sensing unit and the second sensing unit are positioned at the shortest distance from the inverter unit and are connected to the control unit via a wiring harness. Claim 11 A vehicle air conditioning system equipped with a compressor as described in any one of Clause 1 or Clauses 5 through 10. Claim 12 A first step of determining the power status of the compressor; a second step of detecting the pressure and temperature of the suction refrigerant sucked into the compressor; and a third step of determining whether the compressor currently corresponds to a low flow rate state after comparing the actual flow rate state of the detected suction refrigerant with a preset low flow rate state. A method for controlling a compressor, comprising a fourth step of controlling the actual suction pressure to increase when the compressor is currently in a low flow rate state, wherein the third step includes a first judgment step of determining whether the temperature of the suction refrigerant is in a normal range and the pressure of the suction refrigerant is in a normal range, and a second judgment step of determining whether the temperature of the suction refrigerant is in a normal range and the pressure of the suction refrigerant is in a pressure state relatively lower than the pressure of the low flow rate state, wherein the fourth step further includes a first rotational speed control step of controlling the compressor to decrease the rotational speed per minute after waiting for t seconds, and the fourth step further includes a second rotational speed control step of stopping the operation of the compressor if, after waiting for t seconds, the rotational speed per minute of the compressor is lower than the rotational speed per minute of the low flow rate state. Claim 13 delete Claim 14 delete Claim 15 delete

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