Patent Publication Number: US-2023158860-A1

Title: Method for Controlling Vehicle Thermal Management System

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 10-2021-0161624, filed on Nov. 22, 2021, which application is hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a method for controlling a vehicle thermal management system. 
     BACKGROUND 
     With a growing interest in energy efficiency and environmental issues, there is a demand for development of eco-friendly vehicles that can replace internal combustion engine vehicles. Such eco-friendly vehicles are classified into electric vehicles which are driven by using fuel cells or electricity as a power source and hybrid vehicles which are driven by using an engine and a battery. 
     Existing electric vehicles and hybrid vehicles have employed an air-cooled battery cooling system using interior cold air. In recent years, research is underway on a water-cooled battery cooling system that cools the battery by water cooling in order to extend all electric range (AER) to 300 km (200 miles) or more. Specifically, energy density may be increased by adopting a system that cools the battery in a water-cooled manner using a heating, ventilation, and air conditioning (HVAC) system, a radiator, and the like. In addition, the water-cooled battery cooling system may make the battery system compact by reducing gaps between battery cells, and improve battery performance and durability by maintaining a uniform temperature between the battery cells. 
     In order to implement the above-described water-cooled battery cooling system, research is being conducted on a vehicle thermal management system integrated with a powertrain cooling subsystem for cooling an electric motor and power electronics, a battery cooling subsystem for cooling a battery, and an HVAC subsystem for heating or cooling air in a passenger compartment. 
     The HVAC subsystem may include an evaporator, a compressor, a condenser, and a refrigerant loop fluidly connected to an expansion valve located on the upstream side of the evaporator, and a refrigerant may circulate through the refrigerant loop. 
     The powertrain cooling subsystem may include a powertrain coolant loop fluidly connected to the power electronics (an electric motor, an inverter, etc.), and a coolant may circulate through the powertrain coolant loop. The coolant circulating in the powertrain coolant loop may be cooled by an electric radiator. 
     The battery cooling subsystem may include a battery coolant loop fluidly connected to the battery and a battery chiller, and a coolant may circulate through the battery coolant loop. The battery chiller may be configured to transfer heat between a branch line branching off from the refrigerant loop and the battery coolant loop, and the coolant cooled by the refrigerant in the battery chiller may cool the battery. 
     The compressor in the HVAC subsystem may be an inverter compressor including an inverter, and the refrigerant may pass through a refrigerant passage adjacent to the inverter so as to properly cool the inverter. When the flow rate of the refrigerant passing through the refrigerant passage is insufficient or the temperature of the refrigerant is relatively high, the inverter may be overheated, and thus the inverter may not be normally controlled or elements of the inverter may be damaged. 
     The above information described in this background section is provided to assist in understanding the background of the inventive concept, and may include any technical concept which is not considered as the prior art that is already known to those skilled in the art. 
     SUMMARY 
     The present disclosure relates to a method for controlling a vehicle thermal management system. Particular embodiments relate to a method for controlling a vehicle thermal management system preventing an inverter of an electric compressor from overheating. 
     Embodiments of the present disclosure can solve problems occurring in the prior art while advantages achieved by the prior art are maintained intact. 
     An embodiment of the present disclosure provides a method for controlling a vehicle thermal management system effectively preventing an inverter of an electric compressor from overheating. 
     According to an embodiment of the present disclosure, a method for controlling a vehicle thermal management system may include determining, by a controller, a target temperature of an evaporator by subtracting a predetermined temperature from a measured temperature of the evaporator when only the interior cooling of a passenger compartment is performed and a measured temperature of an inverter is higher than a threshold temperature, and adjusting the RPM of a compressor in response to the determined target temperature of the evaporator. 
     As the RPM of the compressor increases, the flow rate of a refrigerant passing through a refrigerant passage adjacent to the inverter may increase, and accordingly the inverter may be properly cooled. 
     The predetermined temperature may increase as the measured temperature of the inverter increases. 
     The target temperature of the evaporator may be variably lowered according to the measured temperature of the inverter. 
     According to another embodiment of the present disclosure, a method for controlling a vehicle thermal management system may include determining, by a controller, a super heat degree of a refrigerant exiting from a battery chiller by subtracting a predetermined temperature from a temperature of the refrigerant measured at an outlet of the battery chiller when the interior cooling of a passenger compartment is not performed, only the cooling of a battery pack is performed, and a measured temperature of an inverter is higher than a threshold temperature, and increasing an opening degree of a chiller-side expansion valve according to the determined super heat degree of the refrigerant. 
     As the opening degree of the chiller-side expansion valve increases, the flow rate of the refrigerant passing through the refrigerant passage adjacent to the inverter may increase, and accordingly the inverter may be properly cooled. 
     According to another embodiment of the present disclosure, a method for controlling a vehicle thermal management system may include determining, by a controller, a target temperature of an evaporator by subtracting a predetermined temperature from a measured temperature of the evaporator when the interior cooling of a passenger compartment and the cooling of a battery pack are performed simultaneously and a measured temperature of an inverter is higher than a threshold temperature, increasing a maximum threshold pressure of a refrigerant compressed by a compressor by a predetermined pressure, and increasing the RPM of the compressor according to the increased maximum threshold pressure of the refrigerant. 
     As the RPM of the compressor increases, the flow rate of the refrigerant passing through the refrigerant passage adjacent to the inverter may increase, and accordingly the inverter may be properly cooled. 
     The method may further include limiting an opening degree of a chiller-side expansion valve. By limiting the opening degree of the chiller-side expansion valve, the flow rate of the refrigerant passing through a first passage of a battery chiller may be relatively limited, and accordingly an increase in the temperature of the refrigerant passing through the refrigerant passage adjacent to the inverter may be minimized. 
     The opening degree of the chiller-side expansion valve may be variably limited according to the measured temperature of the inverter. 
     The opening degree of the chiller-side expansion valve may be reduced as the measured temperature of the inverter increases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of embodiments of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    illustrates a vehicle thermal management system according to an exemplary embodiment of the present disclosure; 
         FIG.  2    illustrates an inverter of a compressor in a vehicle thermal management system according to an exemplary embodiment of the present disclosure; and 
         FIG.  3    illustrates a flowchart of a method for controlling a vehicle thermal management system according to an exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals will be used throughout to designate the same or equivalent elements. In addition, a detailed description of well-known techniques associated with the present disclosure will be omitted in order not to unnecessarily obscure the gist of the present disclosure. 
     Terms such as first, second, A, B, (a), and (b) may be used to describe the elements in exemplary embodiments of the present disclosure. These terms are only used to distinguish one element from another element, and the intrinsic features, sequence or order, and the like of the corresponding elements are not limited by the terms. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those with ordinary knowledge in the field of art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted as having meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted as having ideal or excessively formal meanings unless clearly defined as having such in the present application. 
     Referring to  FIG.  1   , a vehicle thermal management system according to an exemplary embodiment of the present disclosure may include a heating, ventilation, and air conditioning (HVAC) subsystem  11  including a refrigerant loop  21  through which a refrigerant circulates, a battery cooling subsystem  12  including a battery coolant loop  22  through which a battery-side coolant for cooling a battery pack  41  circulates, and a powertrain cooling subsystem  13  including a powertrain coolant loop  23  through which a powertrain-side coolant for cooling an electric motor  51  and power electronics  52  of a powertrain circulates. 
     The HVAC subsystem  11  may be configured to heat or cool air in the passenger compartment of the vehicle using the refrigerant circulating in the refrigerant loop  21 . The refrigerant loop  21  may be fluidly connected to an evaporator  31 , a compressor  32 , an interior condenser  33 , a heating-side expansion valve  16 , a water-cooled heat exchanger  70 , an exterior heat exchanger  35 , and a cooling-side expansion valve  15 . In  FIG.  1   , the refrigerant may sequentially pass through the compressor  32 , the interior condenser  33 , the heating-side expansion valve  16 , the water-cooled heat exchanger  70 , the exterior heat exchanger  35 , the cooling-side expansion valve  15 , and the evaporator  31  through the refrigerant loop  21 . 
     The evaporator  31  may be configured to evaporate the refrigerant received from the cooling-side expansion valve  15 . That is, the refrigerant expanded by the cooling-side expansion valve  15  may be evaporated by absorbing heat from the air in the evaporator  31 . During a cooling operation of the HVAC subsystem  11 , the evaporator  31  may be configured to cool the air using the refrigerant cooled by the exterior heat exchanger  35  and expanded by the cooling-side expansion valve  15 , and the air cooled by the evaporator  31  may be directed into the passenger compartment. 
     The compressor  32  may be configured to compress the refrigerant received from the evaporator  31  and/or a battery chiller  37 . According to an exemplary embodiment, the compressor  32  may be an inverter compressor including an inverter  80 . 
     The compressor  32  may include a compressor motor and a compression section driven by the compressor motor. The refrigerant loop  21  may be fluidly connected to the compression section of the compressor  32 . 
     Referring to  FIG.  2   , the compressor  32  may include a motor housing  32   a  covering the compressor motor, and the inverter  80  may be disposed adjacent to the motor housing  32   a  of the compressor  32 . In the inverter  80 , one or more elements  81  such as an insulated gate bipolar transistor (IGBT) may be mounted on the motor housing  32   a  by a clamp  82 . A printed circuit board (PCB)  83  may be disposed above the element  81  and the clamp  82 , and a temperature sensor  84  for sensing a temperature of the inverter  80  may be mounted on the PCB  83 . The motor housing  32   a  may have a refrigerant passage  32   b , and the refrigerant passage  32   b  may be connected to the refrigerant loop  21 . Specifically, the refrigerant passage  32   b  of the motor housing  32   a  may be fluidly connected to an accumulator  38 . As the refrigerant discharged from the accumulator  38  passes through the refrigerant passage  32   b , the inverter  80  may be properly cooled by the refrigerant. 
     The interior condenser  33  may be configured to condense the refrigerant received from the compressor  32 , and accordingly the air passing through the interior condenser  33  may be heated by the interior condenser  33 . As the air heated by the interior condenser  33  is directed into the passenger compartment, the passenger compartment may be heated. 
     The exterior heat exchanger  35  may be disposed adjacent to a front grille of the vehicle. Since the exterior heat exchanger  35  is exposed to the outside, heat may be transferred between the exterior heat exchanger  35  and the ambient air. During the cooling operation of the HVAC subsystem  11 , the exterior heat exchanger  35  may be configured to condense the refrigerant received from the interior condenser  33 . That is, the exterior heat exchanger  35  may serve as an exterior condenser that condenses the refrigerant by transferring heat to the ambient air during the cooling operation of the HVAC subsystem  11 . During a heating operation of the HVAC subsystem  11 , the exterior heat exchanger  35  may be configured to evaporate the refrigerant received from the water-cooled heat exchanger  70 . That is, the exterior heat exchanger  35  may serve as an exterior evaporator that evaporates the refrigerant by absorbing heat from the ambient air during the heating operation of the HVAC subsystem  11 . In particular, the exterior heat exchanger  35  may exchange heat with the ambient air forcibly blown by a cooling fan  75  so that a heat transfer rate between the exterior heat exchanger  35  and the ambient air may be further increased. 
     The water-cooled heat exchanger  70  may be configured to transfer heat among the refrigerant loop  21  of the HVAC subsystem  11 , the battery coolant loop  22  of the battery cooling subsystem  12 , and the powertrain coolant loop  23  of the powertrain cooling subsystem  13 . Specifically, the water-cooled heat exchanger  70  may be disposed between the interior condenser  33  and the exterior heat exchanger  35  in the refrigerant loop  21 . The water-cooled heat exchanger  70  may include a first passage  71  fluidly connected to the powertrain coolant loop  23 , a second passage  72  fluidly connected to the battery coolant loop  22 , and a third passage  73  fluidly connected to the refrigerant loop  21 . 
     During the heating operation of the HVAC subsystem  11 , the water-cooled heat exchanger  70  may be configured to evaporate the refrigerant which is received from the interior condenser  33  using heat which is received from the powertrain cooling subsystem  13 . That is, during the heating operation of the HVAC subsystem  11 , the water-cooled heat exchanger  70  may serve as an evaporator that evaporates the refrigerant by recovering waste heat from the electric motor  51  and the power electronics  52  of the powertrain cooling subsystem  13 . 
     During the cooling operation of the HVAC subsystem  11 , the water-cooled heat exchanger  70  may be configured to condense the refrigerant received from the interior condenser  33 . The water-cooled heat exchanger  70  may serve as a condenser that condenses the refrigerant by cooling the refrigerant using the battery-side coolant circulating in the battery coolant loop  22  of the battery cooling subsystem  12  and the powertrain-side coolant circulating in the powertrain coolant loop  23  of the powertrain cooling subsystem  13 . 
     The heating-side expansion valve  16  may be located on the upstream side of the water-cooled heat exchanger  70  in the refrigerant loop  21 . Specifically, the heating-side expansion valve  16  may be disposed between the interior condenser  33  and the water-cooled heat exchanger  70 . During the heating operation of the HVAC subsystem  11 , the heating-side expansion valve  16  may adjust the flow of the refrigerant or the flow rate of the refrigerant into the water-cooled heat exchanger  70 . The heating-side expansion valve  16  may be configured to expand the refrigerant received from the interior condenser  33  during the heating operation of the HVAC subsystem  11 . 
     According to an exemplary embodiment, the heating-side expansion valve  16  may be an electronic expansion valve (EXV) having a drive motor  16   a . The drive motor  16   a  may have a shaft which is movable to open or close an orifice defined in a valve body of the heating-side expansion valve  16 , and the position of the shaft may be varied depending on the rotation direction, rotation degree, and the like of the drive motor  16   a , and thus the opening degree of the orifice of the heating-side expansion valve  16  may be varied. A controller  100  may control the operation of the drive motor  16   a . The heating-side expansion valve  16  may be a full open type EXV. 
     The opening degree of the heating-side expansion valve  16  may be varied by the controller  100 . As the opening degree of the heating-side expansion valve  16  is varied, the flow rate of the refrigerant into the third passage  73  may be varied. The heating-side expansion valve  16  may be controlled by the controller boo during the heating operation of the HVAC subsystem  11 . 
     The cooling-side expansion valve  15  may be disposed between the exterior heat exchanger  35  and the evaporator  31  in the refrigerant loop  21 . As the cooling-side expansion valve  15  is located on the upstream side of the evaporator  31 , the cooling-side expansion valve  15  may adjust the flow of the refrigerant or the flow rate of the refrigerant into the evaporator  31 . During the cooling operation of the HVAC subsystem  11 , the cooling-side expansion valve  15  may be configured to expand the refrigerant received from the exterior heat exchanger  35 . 
     According to an exemplary embodiment, the cooling-side expansion valve  15  may be a thermal expansion valve (TXV) which senses the temperature and/or pressure of the refrigerant and adjusts the opening degree of the cooling-side expansion valve  15 . Specifically, the cooling-side expansion valve  15  may be a TXV having a shut-off valve  15   a  selectively blocking the flow of the refrigerant toward an internal passage of the cooling-side expansion valve  15 , and the shut-off valve  15   a  may be a solenoid valve. The shut-off valve  15   a  may be opened or closed by the controller  100 , thereby blocking or unblocking the flow of the refrigerant toward the cooling-side expansion valve  15 . When the shut-off valve  15   a  is opened, the refrigerant may be allowed to flow into the cooling-side expansion valve  15 , and when the shut-off valve  15   a  is closed, the refrigerant may be blocked from flowing into the cooling-side expansion valve  15 . According to an exemplary embodiment, the shut-off valve  15   a  may be mounted in the inside of a valve body of the cooling-side expansion valve  15 , thereby opening or closing the internal passage of the cooling-side expansion valve  15 . According to another exemplary embodiment, the shut-off valve  15   a  may be located on the upstream side of the cooling-side expansion valve  15 , thereby selectively opening or closing an inlet of the cooling-side expansion valve  15 . 
     When the shut-off valve  15   a  is closed, the flow of the refrigerant into the cooling-side expansion valve  15  may be blocked, and accordingly the refrigerant may only be directed into the battery chiller  37  without flowing into the cooling-side expansion valve  15  and the evaporator  31 . That is, when the shut-off valve  15   a  of the cooling-side expansion valve  15  is closed, the cooling operation of the HVAC subsystem  11  may not be performed, and only the battery chiller  37  may be cooled or the heating operation of the HVAC subsystem  11  may be performed. When the shut-off valve  15   a  is opened, the refrigerant may be directed into the cooling-side expansion valve  15  and the evaporator  31 . That is, when the shut-off valve  15   a  of the cooling-side expansion valve  15  is opened, the cooling operation of the HVAC subsystem  11  may be performed. 
     The HVAC subsystem  11  may include an HVAC housing  30  having an inlet and an outlet. The HVAC housing  30  may be configured to allow the air to be directed into the passenger compartment of the vehicle. The evaporator  31  and the interior condenser  33  may be located in the HVAC housing  30 . An air mixing door  34 a may be disposed between the evaporator  31  and the interior condenser  33 , and a positive temperature coefficient (PTC) heater  34   b  may be located on the downstream side of the interior condenser  33 . 
     The HVAC subsystem  11  may further include the accumulator  38  disposed between the evaporator  31  and the compressor  32  in the refrigerant loop  21 , and the accumulator  38  may be located on the downstream side of the evaporator  31 . The accumulator  38  may separate a liquid refrigerant from the refrigerant which is received from the evaporator  31 , thereby preventing the liquid refrigerant from entering the compressor  32 . 
     The HVAC subsystem  11  may further include a branch conduit  36  branching off from the refrigerant loop  21 . The branch conduit  36  may branch off from an upstream point of the cooling-side expansion valve  15  and be connected to the compressor  32  in the refrigerant loop  21 . The battery chiller  37  may be fluidly connected to the branch conduit  36 , and the battery chiller  37  may be configured to transfer heat between the branch conduit  36  and the battery coolant loop  22  to be described below. That is, the battery chiller  37  may be configured to transfer heat between the refrigerant circulating in the HVAC subsystem  11  and the battery-side coolant circulating in the battery cooling subsystem  12 . 
     Specifically, the battery chiller  37  may include a first passage  37   a  fluidly connected to the branch conduit  36  and a second passage  37   b  fluidly connected to the battery coolant loop  22 . The first passage  37   a  and the second passage  37   b  may be adjacent to or contact each other within the battery chiller  37 , and the first passage  37   a  may be fluidly separated from the second passage  37   b . Accordingly, the battery chiller  37  may transfer heat between the battery-side coolant passing through the second passage  37   b  and the refrigerant passing through the first passage  37   a . The refrigerant may be vaporized and superheated by absorbing heat from the battery-side coolant, and the battery-side coolant may be cooled by releasing heat to the refrigerant. 
     The branch conduit  36  may be fluidly connected to the accumulator  38 , and the refrigerant passing through the branch conduit  36  may be received in the accumulator  38 . 
     A chiller-side expansion valve  17  may be located on the upstream side of the battery chiller  37  in the branch conduit  36 . The chiller-side expansion valve  17  may adjust the flow of the refrigerant or the flow rate of the refrigerant into the battery chiller  37 , and the chiller-side expansion valve  17  may be configured to expand the refrigerant received from the exterior heat exchanger  35 . 
     According to an exemplary embodiment, the chiller-side expansion valve  17  may be an EXV having a drive motor  17   a . The drive motor  17   a  may have a shaft which is movable to open or close an orifice defined in a valve body of the chiller-side expansion valve  17 , and the position of the shaft may be varied depending on the rotation direction, rotation degree, and the like of the drive motor  17   a , and thus the opening degree of the chiller-side expansion valve  17  may be varied. That is, the controller  100  may control the operation of the drive motor  17   a  so that the opening degree of the chiller-side expansion valve  17  may be varied. The chiller-side expansion valve  17  may be a full open type EXV. The chiller-side expansion valve  17  may have a structure which is the same as or similar to that of the heating-side expansion valve  16 . 
     As the opening degree of the chiller-side expansion valve  17  is varied, the flow rate of the refrigerant into the battery chiller  37  may be varied. For example, when the opening degree of the chiller-side expansion valve  17  is greater than a reference opening degree, the flow rate of the refrigerant into the battery chiller  37  may be relatively increased above a reference flow rate, and when the opening degree of the chiller-side expansion valve  17  is less than the reference opening degree, the flow rate of the refrigerant into the battery chiller  37  may be similar to the reference flow rate or be relatively lowered below the reference flow rate. Here, the reference opening degree refers to an opening degree of the chiller-side expansion valve  17  required for maintaining a target evaporator temperature, and the reference flow rate refers to a flow rate of the refrigerant which is allowed to flow into the battery chiller  37  when the chiller-side expansion valve  17  is opened to the reference opening degree. When the chiller-side expansion valve  17  is opened to the reference opening degree, the refrigerant may be directed into the battery chiller  37  at a corresponding reference flow rate. 
     As the opening degree of the chiller-side expansion valve  17  is adjusted by the controller  100 , the flow rate of the refrigerant into the battery chiller  37  may be varied, and accordingly the flow rate of the refrigerant into the evaporator  31  may be varied. As the opening degree of the chiller-side expansion valve  17  is adjusted, the refrigerant may be distributed to the evaporator  31  and the battery chiller  37  at a predetermined ratio, and thus the cooling of the HVAC subsystem  11  and the cooling of the battery chiller  37  may be performed simultaneously or selectively. 
     The HVAC subsystem  11  may further include a refrigerant bypass conduit  39  connecting a downstream point of the third passage  73  of the water-cooled heat exchanger  70  and the branch conduit  36 . An inlet of the refrigerant bypass conduit  39  may be connected to the downstream point of the water-cooled heat exchanger  70 , and an outlet of the refrigerant bypass conduit  39  may be connected to the branch conduit  36 . Specifically, the inlet of the refrigerant bypass conduit  39  may be connected to a point between the water-cooled heat exchanger  70  and the exterior heat exchanger  35 , and the outlet of the refrigerant bypass conduit  39  may be connected to a point between the battery chiller  37  and the compressor  32  in the branch conduit  36 . A first three-way valve  61  may be disposed at a junction between the inlet of the refrigerant bypass conduit  39  and the refrigerant loop  21 . The first three-way valve  61  may be disposed between the exterior heat exchanger  35  and the water-cooled heat exchanger  70  in the refrigerant loop  21 . When the first three-way valve  61  is switched to open the inlet of the refrigerant bypass conduit  39 , the refrigerant exiting from the third passage  73  of the water-cooled heat exchanger  70  may be directed into the compressor  32  through the refrigerant bypass conduit  39  and the accumulator  38 . That is, when the inlet of the refrigerant bypass conduit  39  is opened by the switching of the first three-way valve  61 , the refrigerant may bypass the exterior heat exchanger  35 . When the first three-way valve  61  is switched to close the inlet of the refrigerant bypass conduit  39 , the refrigerant exiting from the third passage  73  of the water-cooled heat exchanger  70  may be directed into the exterior heat exchanger  35  without passing through the refrigerant bypass conduit  39 . That is, when the inlet of the refrigerant bypass conduit  39  is closed by the switching of the first three-way valve  61 , the refrigerant may pass through the exterior heat exchanger  35 . 
     The controller  100  may control respective operations of the shut-off valve  15   a  of the cooling-side expansion valve  15 , the heating-side expansion valve  16 , the chiller-side expansion valve  17 , the compressor  32 , and the like, and thus the overall operation of the HVAC subsystem  11  may be controlled by the controller  100 . According to an exemplary embodiment, the controller  100  may be a full automatic temperature control (FATC) system. 
     When the HVAC subsystem  11  operates in a cooling mode, the shut-off valve  15   a  of the cooling-side expansion valve  15  may be opened, and the refrigerant may sequentially circulate through the compressor  32 , the interior condenser  33 , the heating-side expansion valve  16 , the third passage  73  of the water-cooled heat exchanger  70 , the exterior heat exchanger  35 , the cooling-side expansion valve  15 , and the evaporator  31 . 
     When the HVAC subsystem  11  operates in a heating mode, the shut-off valve  15   a  of the cooling-side expansion valve  15  may be closed, and the refrigerant may sequentially circulate through the compressor  32 , the interior condenser  33 , the heating-side expansion valve  16 , the third passage  73  of the water-cooled heat exchanger  70 , the exterior heat exchanger  35 , the chiller-side expansion valve  17 , the first passage  37   a  of the battery chiller  37 , and the compressor  32 . During the heating operation of the HVAC subsystem  11 , when the shut-off valve  15   a  of the cooling-side expansion valve  15  is closed, and the inlet of the refrigerant bypass conduit  39  is opened by the switching of the first three-way valve  61 , the refrigerant may sequentially circulate through the compressor  32 , the interior condenser  33 , the heating-side expansion valve  16 , the third passage  73  of the water-cooled heat exchanger  70 , and the compressor  32 . 
     The battery cooling subsystem  12  may be configured to cool the battery pack  41  using the battery-side coolant circulating in the battery coolant loop  22 . The battery coolant loop  22  may be fluidly connected to the battery pack  41 , a heater  42 , the battery chiller  37 , a second battery-side pump  45 , a battery radiator  43 , a reservoir tank  48 , and a first battery-side pump  44 . In  FIG.  1   , the battery-side coolant may sequentially pass through the battery pack  41 , the heater  42 , the battery chiller  37 , the second battery-side pump  45 , the battery radiator  43 , the reservoir tank  48 , the second passage  72  of the water-cooled heat exchanger  70 , and the first battery-side pump  44  through the battery coolant loop  22 . 
     The battery pack  41  may have a coolant passage provided inside or outside thereof, and the battery-side coolant may pass through the coolant passage. The battery coolant loop  22  may be fluidly connected to the coolant passage of the battery pack  41 . 
     The heater  42  may be disposed between the battery chiller  37  and the battery pack  41 , and the heater  42  may heat the battery-side coolant circulating through the battery coolant loop  22  to warm-up the coolant. According to an exemplary embodiment, the heater  42  may be a water-heating heater that heats the coolant by exchanging heat with a high-temperature fluid. According to another exemplary embodiment, the heater  42  may be an electric heater. 
     The battery radiator  43  may be disposed adjacent to the front grille of the vehicle, and the battery-side coolant passing through the battery radiator  43  may be cooled using the ambient air forcibly blown by the cooling fan  75 . The battery radiator  43  may be adjacent to the exterior heat exchanger  35 . 
     The first battery-side pump  44  may be configured to allow the battery-side coolant to circulate through at least a portion of the battery coolant loop  22 , and the second battery-side pump  45  may be configured to allow the battery-side coolant to circulate through at least a portion of the battery coolant loop  22 . 
     The first battery-side pump  44  may be disposed at an upstream point of the battery pack  41  in the battery coolant loop  22 . The first battery-side pump  44  may forcibly pump the battery-side coolant into the battery pack  41 , thereby allowing the battery-side coolant to pass through the battery pack  41 . 
     The second battery-side pump  45  may be disposed at an upstream point of the battery radiator  43  in the battery coolant loop  22 . The second battery-side pump  45  may forcibly pump the battery-side coolant into an inlet of the battery radiator  43 , thereby allowing the battery-side coolant to pass through the battery radiator  43 . 
     The first battery-side pump  44  and the second battery-side pump  45  may operate individually and selectively according to the thermal condition and charging condition of the battery pack  41 , the operating condition of the HVAC subsystem  11 , and the like. 
     The reservoir tank  48  may be disposed between an outlet of the battery radiator  43  and an inlet of the first battery-side pump  44 . 
     The battery cooling subsystem  12  may further include a first battery bypass conduit  46  allowing the battery-side coolant to bypass the battery radiator  43 . The first battery bypass conduit  46  may directly connect the upstream point of the battery radiator  43  and a downstream point of the battery radiator  43  in the battery coolant loop  22 . 
     An inlet of the first battery bypass conduit  46  may be connected to a point between the battery chiller  37  and the inlet of the battery radiator  43  in the battery coolant loop  22 . Specifically, the inlet of the first battery bypass conduit  46  may be connected to a point between the battery chiller  37  and an inlet of the second battery-side pump  45  in the battery coolant loop  22 . 
     An outlet of the first battery bypass conduit  46  may be connected to a point between the battery chiller  37  and the outlet of the battery radiator  43  in the battery coolant loop  22 . Specifically, the outlet of the first battery bypass conduit  46  may be connected to a point between the inlet of the first battery-side pump  44  and an outlet of the reservoir tank  48  in the battery coolant loop  22 . 
     As the battery-side coolant flows from the downstream side of the battery chiller  37  to the upstream side of the first battery-side pump  44  through the first battery bypass conduit  46 , the battery-side coolant may bypass the second battery-side pump  45 , the battery radiator  43 , the reservoir tank  48 , and the water-cooled heat exchanger  70 , and accordingly the battery-side coolant passing through the first battery bypass conduit  46  may sequentially circulate through the battery pack  41 , the heater  42 , and the battery chiller  37  by the first battery-side pump  44 . 
     The battery cooling subsystem  12  may further include a second battery bypass conduit  47  allowing the battery-side coolant to bypass the battery pack  41 , the heater  42 , and the battery chiller  37 . The second battery bypass conduit  47  may directly connect a downstream point of the battery chiller  37  and the upstream point of the battery pack  41  in the battery coolant loop  22 . 
     An inlet of the second battery bypass conduit  47  may be connected to a point between the outlet of the first battery bypass conduit  46  and the outlet of the battery radiator  43  in the battery coolant loop  22 . Specifically, the inlet of the second battery bypass conduit  47  may be connected to a point between the outlet of the first battery bypass conduit  46  and the outlet of the reservoir tank  48  in the battery coolant loop  22 . 
     An outlet of the second battery bypass conduit  47  may be connected to a point between the inlet of the first battery bypass conduit  46  and the inlet of the battery radiator  43  in the battery coolant loop  22 . Specifically, the outlet of the second battery bypass conduit  47  may be connected to a point between the inlet of the first battery bypass conduit  46  and the inlet of the second battery-side pump  45  in the battery coolant loop  22 . As the battery-side coolant flows from the downstream side of the battery radiator  43  to the upstream side of the second battery-side pump  45  through the second battery bypass conduit  47 , the battery-side coolant may bypass the battery pack  41 , the heater  42 , and the battery chiller  37 , and accordingly the battery-side coolant passing through the second battery bypass conduit  47  may sequentially circulate through the battery radiator  43 , the reservoir tank  48 , and the second passage  72  of the water-cooled heat exchanger  70  by the second battery-side pump  45 . 
     The first battery bypass conduit  46  and the second battery bypass conduit  47  may be parallel to each other. 
     The battery cooling subsystem  12  may further include a second three-way valve  62  disposed at the inlet of the first battery bypass conduit  46 . That is, the second three-way valve  62  may be disposed at a junction between the inlet of the first battery bypass conduit  46  and the battery coolant loop  22 . When the second three-way valve  62  is switched to open the inlet of the first battery bypass conduit  46 , a portion of the battery-side coolant (from the battery chiller  37 ) may pass through the first battery bypass conduit  46  so that it may bypass the battery radiator  43 , and the remaining battery-side coolant (from the battery radiator  43 ) may pass through the second battery bypass conduit  47  so that it may bypass the battery pack  41 , the heater  42 , and the battery chiller  37 . That is, when the inlet of the first battery bypass conduit  46  is opened by the switching of the second three-way valve  62 , the battery coolant loop  22  may form a circulation loop in which the first battery bypass conduit  46  and the second battery bypass conduit  47  are independent of each other. The battery-side coolant passing through the first battery bypass conduit  46  may bypass the second battery-side pump  45 , the battery radiator  43 , the reservoir tank  48 , and the water-cooled heat exchanger  70 , and may sequentially circulate through the battery pack  41 , the heater  42 , and the battery chiller  37  by the first battery-side pump  44 . The battery-side coolant passing through the second battery bypass conduit  47  may bypass the first battery-side pump  44 , the battery pack  41 , the heater  42 , and the battery chiller  37 , and may sequentially circulate through the battery radiator  43 , the reservoir tank  48 , and the water-cooled heat exchanger  70  by the second battery-side pump  45 . 
     When the second three-way valve  62  is switched to close the inlet of the first battery bypass conduit  46 , the battery-side coolant may not pass through the first battery bypass conduit  46 . That is, when the inlet of the first battery bypass conduit  46  is closed by the switching of the second three-way valve  62 , the battery-side coolant may circulate through the battery coolant loop  22 . 
     The battery cooling subsystem  12  may be controlled by a battery management system no. The battery management system no may monitor the state of the battery pack  41 , and perform the cooling of the battery pack  41  when the temperature of the battery pack  41  is higher than or equal to a threshold temperature. The battery management system no may transmit an instruction for the cooling of the battery pack  41  to the controller  100 , and accordingly the controller  100  may control the compressor  32  to operate and control the chiller-side expansion valve  17  to open. When the operation of the HVAC subsystem  11  is not required during the cooling operation of the battery pack  41 , the controller  100  may control the cooling-side expansion valve  15  to close. In addition, the battery management system no may control the operation of the first battery-side pump  44  and the switching of the second three-way valve  62  as necessary so that the battery-side coolant may bypass the battery radiator  43  and circulate through the battery pack  41  and the battery chiller  37 . 
     The powertrain cooling subsystem  13  may be configured to cool the electric motor  51  and the power electronics  52  of the powertrain using the powertrain-side coolant circulating through the powertrain coolant loop  23 . The powertrain coolant loop  23  may be fluidly connected to the electric motor  51 , a powertrain radiator  53 , a reservoir tank  56 , the first passage  71  of the water-cooled heat exchanger  70 , a powertrain-side pump  54 , and the power electronics  52 . In  FIG.  1   , the powertrain-side coolant may sequentially pass through the electric motor  51 , the powertrain radiator  53 , the reservoir tank  56 , the first passage  71  of the water-cooled heat exchanger  70 , the powertrain-side pump  54 , and the power electronics  52  through the powertrain coolant loop  23 . 
     The electric motor  51  may have a coolant passage provided inside or outside thereof, and the powertrain-side coolant may pass through the coolant passage. The powertrain coolant loop  23  may be fluidly connected to the coolant passage of the electric motor  51 . 
     The power electronics  52  may be one or more power electronics components related to the driving of the electric motor  51 , such as an inverter, an on-board charger (OBC), and a low DC-DC converter (LDC). The power electronics  52  may have a coolant passage provided inside or outside thereof, and the powertrain-side coolant may pass through the coolant passage. The powertrain coolant loop  23  may be fluidly connected to the coolant passage of the power electronics  52 . 
     The powertrain radiator  53  may be disposed adjacent to the front grille of the vehicle, and the powertrain radiator  53  may be cooled by the ambient air forcibly blown by the cooling fan  75 . The exterior heat exchanger  35 , the battery radiator  43 , and the powertrain radiator  53  may be disposed adjacent to each other on the front of the vehicle. The cooling fan  75  may be disposed behind the exterior heat exchanger  35 , the battery radiator  43 , and the powertrain radiator  53 . 
     The powertrain-side pump  54  may be located on the upstream side of the electric motor  51  and the power electronics  52 , and the powertrain-side pump  54  may allow the powertrain-side coolant to circulate in the powertrain coolant loop  23 . 
     The powertrain cooling subsystem  13  may further include a powertrain bypass conduit  55  allowing the powertrain-side coolant to bypass the powertrain radiator  53 . The powertrain bypass conduit  55  may directly connect an upstream point of the powertrain radiator  53  and a downstream point of the powertrain radiator  53  in the powertrain coolant loop  23  so that the powertrain-side coolant from an outlet of the electric motor  51  may be directed toward an inlet of the powertrain-side pump  54  through the powertrain bypass conduit  55 , and thus the powertrain-side coolant may bypass the powertrain radiator  53 . 
     An inlet of the powertrain bypass conduit  55  may be connected to a point between the electric motor  51  and the powertrain radiator  53  in the powertrain coolant loop  23 . An outlet of the powertrain bypass conduit  55  may be connected to a point between the reservoir tank  56  and the power electronics  52  in the powertrain coolant loop  23 . Specifically, the outlet of the powertrain bypass conduit  55  may be connected to a point between the reservoir tank  56  and the inlet of the powertrain-side pump  54  in the powertrain coolant loop  23 . 
     The powertrain cooling subsystem  13  may further include a third three-way valve  63  disposed at the inlet of the powertrain bypass conduit  55 . The powertrain-side coolant may bypass the powertrain radiator  53  through the powertrain bypass conduit  55  by the switching of the third three-way valve  63 , and the powertrain-side coolant may sequentially pass through the electric motor  51 , the first passage  71  of the water-cooled heat exchanger  70 , and the power electronics  52  by the powertrain-side pump  54 . 
     The reservoir tank  56  may be located on the downstream side of the powertrain radiator  53 . In particular, the reservoir tank  56  may be disposed between the powertrain radiator  53  and the first passage  71  of the water-cooled heat exchanger  70  in the powertrain coolant loop  23 . 
     In the powertrain cooling subsystem  13 , the switching of the third three-way valve  63  and the operation of the powertrain-side pump  54  may be controlled by the controller  100 . 
       FIG.  3    illustrates a flowchart of a method for controlling a vehicle thermal management system according to an exemplary embodiment of the present disclosure. 
     The controller  100  may determine whether only the interior cooling of the passenger compartment is performed as the HVAC subsystem  11  only operates in the cooling mode (S 1 ). 
     When only the interior cooling of the passenger compartment is performed, it may be determined whether a temperature T of the inverter  80  measured by the temperature sensor  84  of the inverter  80  is higher than a threshold temperature A (S 2 ). The threshold temperature A refers to a reference temperature of the inverter  80  at which the operation of the compressor  32  is stopped due to overheating of the inverter  80 . For example, the threshold temperature A may be 125° C. or higher. 
     When the temperature T of the inverter  80  is higher than the threshold temperature A, the controller  100  may lower a target temperature T E  of the evaporator  31  by subtracting a predetermined temperature from a temperature of the evaporator  31  measured by a temperature sensor (S 3 ). The controller  100  may predetermine the target temperature T E  of the evaporator  31  to correspond to a cooling temperature of the passenger compartment set by a user. That is, the target temperature T E  of the evaporator  31  may be a control parameter determined by the controller  100  to match a set cooling mode of the HVAC subsystem  11 . 
     According to a specific exemplary embodiment, the controller  100  may variably reset the target temperature T E  of the evaporator  31  according to the measured temperature T of the inverter  80 . The predetermined temperature may be varied according to the measured temperature T of the inverter  80 . In particular, as the measured temperature T of the inverter  80  increases, the predetermined temperature may increase. For example, when the measured temperature T of the inverter  80  is 126° C., the predetermined temperature may be 1° C., and the controller  100  may subtract 1° C. from the measured temperature T of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . When the measured temperature T of the inverter  80  is 128° C., the predetermined temperature may be 2° C., and the controller  100  may subtract 2° C. from the measured temperature T of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . When the measured temperature T of the inverter  80  is 130° C., the predetermined temperature may be 3° C., and the controller  100  may subtract 3° C. from the measured temperature T of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . 
     As the target temperature T E  of the evaporator  31  is reset (lowered) by the controller  100 , a work amount or rate of the compressor  32  may relatively increase, and accordingly the controller  100  may increase the RPM of the compressor  32  (S 4 ). As the RPM of the compressor  32  increases, the flow rate of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may increase, and accordingly the inverter  80  may be properly cooled. 
     When it is determined in S 1  that the interior cooling of only the passenger compartment is not performed, it may be determined whether only the cooling of the battery pack  41  is performed (S 5 ). 
     When only the cooling of the battery pack  41  is performed, it may be determined whether the temperature T of the inverter  80  measured by the temperature sensor  84  of the inverter  80  is higher than the threshold temperature A (S 6 ). 
     When the temperature T of the inverter  80  is higher than the threshold temperature A, the controller  100  may reduce a super heat degree of the refrigerant exiting from the battery chiller  37  (S 7 ). As the refrigerant passes through the first passage  37   a  of the battery chiller  37 , and the battery-side coolant passes through the second passage  37   b  of the battery chiller  37 , the refrigerant may absorb heat from the battery-side coolant to thereby be vaporized and superheated, and the battery-side coolant may release heat to the refrigerant to thereby be cooled. As the temperature of the battery pack  41  increases, the controller  100  may predetermine the super heat degree of the refrigerant exiting from the battery chiller  37 . That is, the super heat degree of the refrigerant exiting from the battery chiller  37  may be a control parameter determined by the controller  100  to match a cooling mode of the battery cooling subsystem  12 . According to an exemplary embodiment, the super heat degree of the refrigerant may be a temperature of the refrigerant measured at an outlet of the battery chiller  37 , and the temperature of the refrigerant at the outlet of the battery chiller  37  may be measured by a refrigerant sensor. For example, the controller  100  may reset the super heat degree of the refrigerant by subtracting a predetermined temperature (for example, 10° C.) from the temperature of the refrigerant measured at the outlet of the battery chiller  37 , and thus the super heat degree of the refrigerant may be reduced. 
     As the super heat degree of the refrigerant exiting from the battery chiller  37  is reduced by the controller  100 , the controller  100  may increase an opening degree of the chiller-side expansion valve  17  accordingly (S 8 ). As the opening degree of the chiller-side expansion valve  17  increases, the flow rate of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may increase, and accordingly the inverter  80  may be properly cooled. 
     When it is determined in S 5  that only the cooling of the battery pack  41  is not performed, it may be determined whether the interior cooling of the passenger compartment and the cooling of the battery pack  41  are performed simultaneously (S 9 ). 
     When the interior cooling of the passenger compartment and the cooling of the battery pack  41  are performed simultaneously, it may be determined whether a temperature T 1  of the inverter  80  measured by the temperature sensor  84  of the inverter  80  is higher than a threshold temperature A (S 10 ). The threshold temperature A refers to a reference temperature of the inverter  80  at which the operation of the compressor  32  is stopped due to overheating of the inverter  80 . For example, the threshold temperature A may be 125° C. or higher. 
     When the temperature T 1  of the inverter  80  is higher than the threshold temperature A, the controller  100  may lower a target temperature T E  of the evaporator  31  by subtracting a predetermined temperature from a temperature of the evaporator  31  measured by the temperature sensor (S 11 ). The controller  100  may predetermine the target temperature T E  of the evaporator  31  to meet a cooling temperature of the passenger compartment set by the user. That is, the target temperature T E  of the evaporator  31  may be a control parameter determined by the controller  100  to match a set cooling mode of the HVAC subsystem  11 . 
     According to a specific exemplary embodiment, the controller  100  may variably reset the target temperature T E  of the evaporator  31  according to the measured temperature T 1  of the inverter  80 . The predetermined temperature may be varied according to the measured temperature T 1  of the inverter  80 . In particular, as the measured temperature T 1  of the inverter  80  increases, the predetermined temperature may increase. For example, when the measured temperature T 1  of the inverter  80  is 125° C., the predetermined temperature may be 1° C., and the controller  100  may subtract 1° C. from the measured temperature T 1  of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . When the measured temperature T 1  of the inverter  80  is 128° C., the predetermined temperature may be 2° C., and the controller  100  may subtract 2° C. from the measured temperature T 1  of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . When the measured temperature T 1  of the inverter  80  is 130° C., the predetermined temperature may be 3° C., and the controller  100  may subtract 3° C. from the measured temperature T 1  of the inverter  80 , thereby lowering the target temperature T E  of the evaporator  31  below the predetermined target temperature of the evaporator  31 . As the target temperature T E  of the evaporator  31  is reset (lowered) by the controller  100 , a work amount or rate of the compressor  32  may relatively increase, and accordingly the controller  100  may increase the RPM of the compressor  32  (S 11 ). As the RPM of the compressor  32  increases, the flow rate of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may increase, and accordingly the inverter  80  may be properly cooled. 
     After S 11 , a temperature T 2  of the inverter  80  may be secondarily measured by the temperature sensor  84 , and it may be determined whether the measured temperature T 2  of the inverter  80  is higher than the threshold temperature A (S 12 ). 
     When the temperature T 2  of the inverter  80  is higher than the threshold temperature A, the controller  100  may increase a maximum threshold pressure of the refrigerant compressed by the compressor  32  by a predetermined pressure (S 13 ). When the pressure of the refrigerant compressed by the compressor  32  increases excessively, some components of the HVAC subsystem  11  may be damaged or the compressor  32  may be overloaded. In order to prevent the pressure of the refrigerant discharged from the compressor  32  from excessively increasing, the controller  100  may control the compressor  32  according to high-pressure protection logic so that the pressure of the refrigerant compressed by the compressor  32  may not exceed the maximum threshold pressure (for example, 350 psi). That is, the high-pressure protection logic may be designed to determine the maximum threshold pressure to limit the pressure of the refrigerant compressed by the compressor  32 . 
     For example, when the vehicle performs rapid charging at a high ambient temperature or a maximum cooling operation of the passenger compartment is performed, the inverter  80  attached to the compressor may be overheated. However, since the operation of the compressor is limited by the high-pressure protection logic, the flow rate of the refrigerant for cooling the overheated inverter may be insufficient. Accordingly, the inverter  80  may be stopped, and the compressor  32  may be stopped. The controller  100  may add a predetermined pressure to the maximum threshold pressure of the refrigerant determined by the high-pressure protection logic, thereby increasing the maximum threshold pressure of the refrigerant. For example, the maximum threshold pressure of the refrigerant may increase from 350 psi to 380 psi. 
     The controller  100  may increase the RPM of the compressor  32  according to an increase in the maximum threshold pressure of the refrigerant (S 14 ). As the RPM of the compressor  32  increases, the flow rate of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may increase, and accordingly the inverter  80  may be properly cooled. 
     After S 14 , a temperature T 3  of the inverter  80  may be thirdly measured by the temperature sensor  84 , and it may be determined whether the measured temperature T 3  of the inverter  80  is higher than the threshold temperature A (S 15 ). 
     Meanwhile, when the interior cooling of the passenger compartment and the cooling of the battery pack  41  are performed simultaneously, the refrigerant may be distributed to the evaporator  31  and the first passage  37   a  of the battery chiller  37 . Here, when the flow rate of the refrigerant into the first passage  37   a  of the battery chiller  37  is higher than the flow rate of the refrigerant into the evaporator  31 , the temperature of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may relatively increase. When the temperature of the refrigerant increases, the inverter  80  may not be properly cooled even if the flow rate of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  relatively increases. 
     According to an exemplary embodiment of the present disclosure, when the temperature T 3  of the inverter  80  measured in S 15  is higher than the threshold temperature A, the controller  100  may limit an opening degree of the chiller-side expansion valve  17  (S 16 ). By limiting the opening degree of the chiller-side expansion valve  17 , the flow rate of the refrigerant passing through the first passage  37   a  of the battery chiller  37  may be relatively limited, and accordingly an increase in the temperature of the refrigerant passing through the refrigerant passage  32   b  adjacent to the inverter  80  may be minimized. As the measured temperature T 3  of the inverter  80  varies, the controller  100  may variably limit the opening degree of the chiller-side expansion valve  17 . In particular, as the measured temperature T 3  of the inverter  80  increases, the controller  100  may variably reduce the opening degree of the chiller-side expansion valve  17 . For example, when the measured temperature T 3  of the inverter  80  is 125° C., the controller  100  may limit the opening degree of the chiller-side expansion valve  17  to 80%. When the measured temperature T 3  of the inverter  80  is 130° C., the controller  100  may limit the opening degree of the chiller-side expansion valve  17  to 70%. When the measured temperature T 3  of the inverter  80  is 135° C., the controller  100  may limit the opening degree of the chiller-side expansion valve  17  to 60%. 
     As set forth above, the method for controlling a vehicle thermal management system according to exemplary embodiments of the present disclosure may be designed to temporarily reduce the flow rate and temperature of the refrigerant passing through the refrigerant passage adjacent to the inverter, thereby effectively preventing the inverter of the electric compressor from overheating. 
     Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.