TRACTION BATTERY COOLING SYSTEM WITH COOLANT PROPORTIONAL VALVE

Abstract

Cooling system (10) for an electrified motor vehicle comprising: a coolant circuit (12) circulating coolant between a traction battery (14) and a battery cooler (15) or cooling device (16); a refrigerant circuit (18) circulating refrigerant between an air conditioning compressor (20), an air conditioning condenser (22) and a first evaporator (241) or the cooling device (16); multiple flow control valves in the coolant circuit (12) and the refrigerant circuit (18); and a control system (50) comprising a controller (52) designed to (a) control the operation of the multiple flow control valves and (b) prioritize interior cooling over traction battery cooling when the traction battery (14) is at normal operating temperature;wherein the coolant circuit (12) further comprises a coolant bypass (35) and the multiple flow control valves comprise a coolant proportional valve (37) in the coolant circuit (12) between the traction battery (14) and the cooling device (16) for controlling a flow of coolant through the cooling device (16), wherein the controller (52) is designed to determine a maximum opening position of the coolant proportional valve (37) as a function of the air conditioning capacity of the cooling device (16), wherein the controller (52) is designed to determine a setpoint opening position of the coolant proportional valve (37) as an output of a PI control of the battery coolant temperature and to determine a final opening position of the coolant proportional valve (37) as a function of the maximum opening position of the coolant proportional valve (37) and the setpoint opening position of the coolant proportional valve (37).

Description

TECHNICAL FIELDThis document relates generally to the field of automotive equipment and, more particularly, to a traction battery cooling system for an electrified motor vehicle. The cooling system uses a coolant proportional valve and a refrigerant-to-coolant heat exchange cooling device.BACKGROUNDHybrid electric vehicles and electric vehicles use an electric motor for vehicle propulsion. The electric motor is powered by a traction battery. The traction battery is configured to store an electrical charge and may also be used to power other vehicle components. By efficient use of the battery, the range of the motor vehicle can be significantly increased. Because the availability of battery energy is affected by the battery temperature, hybrid and electric vehicles generally include a liquid cooling system for the traction battery. Many such systems utilize a refrigerant-to-coolant cooling device coupled to the vehicle interior cooling / heating, ventilation, and air conditioning (HVAC) system. Thus, use of the cooling device to cool the traction battery may result in temperature fluctuations of the conditioned air discharged into the vehicle interior. Such temperature fluctuations can be noticeable by vehicle occupants and therefore be undesirable. US 2013 / 0 298 583 A1 discloses a battery-centered thermal thermal thermal management system using a heat exchanger mixing valve. DE 10 2017 101 218 A1 discloses a vehicle interior air conditioning and battery cooling system.This document relates to a new and improved traction battery cooling system for an electrified motor vehicle that limits or substantially eliminates these temperature variations under normal operating conditions, thereby increasing vehicle occupant comfort and satisfaction. This object is achieved with the features of the independent claims. Preferred embodiments for this are specified in the further patent claims.SUMMARYIn accordance with the purposes and advantages described herein, a traction battery cooling system for an electrified motor vehicle is provided. The cooling system includes a coolant circuit, a refrigerant circuit, a plurality of flow control valves, and a control system.In the coolant circuit, coolant is circulated between the traction battery and a battery cooler or cooling device. The coolant circuit also includes a cooling device bypass. The refrigerant circuit circulates refrigerant between a compressor, a condenser, and a first evaporator or the cooling device. The plurality of flow control valves are provided in the coolant circuit and the refrigerant circuit. The plurality of flow control valves includes a coolant proportional valve in the coolant circuit between the traction battery and the cooling device for controlling the flow of coolant through the cooling device.The control system includes a controller configured to (a) control operation of the plurality of flow control valves and (b) prioritize cabin cooling over traction battery cooling when the traction battery has a normal or acceptable operating temperature. Advantageously, the cooling system delays use of the cooling device for battery cooling until the HVAC load for the vehicle interior is stabilized and below a total climate capacity, thereby reducing or substantially eliminating undesirable variations in the conditioned air discharged by the HVAC system into the vehicle interior.In some possible embodiments, the controller is configured to include a first data input for an ambient air temperature. Further, the controller is configured to include a second data input for an HVAC blower speed. In addition, the controller is configured to include a third data input for an evaporator temperature. Additionally, the control system may further include an ambient temperature sensor and an evaporator temperature sensor connected to the first and third data inputs, respectively.In some possible embodiments, the plurality of flow control valves includes a battery coolant valve in the coolant circuit downstream of the traction battery and upstream of the battery cooler and coolant proportional valve. The valve controls the flow of coolant from the traction battery to the battery cooler or coolant proportional valve.In some embodiments, the plurality of flow control valves includes a thermal expansion device in the refrigerant circuit between the condenser and the cooling device for controlling a flow of refrigerant from the condenser into the cooling device.In some embodiments, the controller includes a fourth data input for a traction battery temperature. In some embodiments, the controller includes a fifth data input for a coolant temperature. In such embodiments, the control system may further include a traction battery temperature sensor and a coolant temperature sensor.In yet another aspect, a method is provided for controlling traction battery cooling while limiting temperature variations of conditioned air discharged into an interior of an electrified motor vehicle. The method includes the steps of: (a) prioritizing, by a controller, interior cooling over traction battery cooling based on an HVAC load and evaporator deviation; and (b) controlling a flow of battery coolant to a cooling device using a coolant proportional valve controlled by the controller.Further, the method may further comprise the steps of: (a) monitoring, by a first device, an ambient air temperature, (b) monitoring, by a second device, an HVAC blower speed, and (c) monitoring, by a third device, an evaporator temperature.The method may further include the step of determining, by the controller, an HVAC load based on an indicated HVAC blower speed and an indicated ambient air temperature. Additionally, the method may include the steps of determining, by the controller, an evaporator deviation by comparing an indicated evaporator temperature to a desired evaporator temperature and determining, by the controller, an air conditioning capacity of the cooling device as a function of evaporator deviation and HVAC load.Further, the method may further comprise the step of monitoring, by a fourth device, a traction battery coolant temperature. Further, the method may further include the step of calculating, by the controller, a target traction battery coolant temperature based on the traction battery temperature.Additionally, the method may further include other steps, such as controlling, by the controller, the flow of coolant to the cooling device based on an indicated traction battery temperature versus a desired traction battery temperature.Further, the method may further comprise the step of determining, by the controller, a maximum opening position of the coolant proportional valve as a function of the air conditioning capacity of the cooling device. The valve opening position determines the flow rate of coolant to the cooling device. The method may further include the steps of determining, by the controller, a desired opening position of the coolant proportional valve as an output of a proportional-integral (PI) control of the battery coolant temperature and determining, by the controller, a final opening position of the coolant proportional valve as a function of the maximum opening position of the coolant proportional valve and the desired opening position of the coolant proportional valve.The method may also include the steps of fully opening, by the controller, the coolant proportional valve to the cooling device and controlling, by the controller, a compressor speed based on a battery coolant temperature deviation when operating in the battery-only cooling mode.In the following description, there are shown and described several preferred embodiments of the cooling system and method of controlling traction battery cooling while limiting temperature variations of the conditioned air discharged into the interior of an electrified motor vehicle. As it should be realized, other different embodiments of the cooling system and method are possible, and their several details are modifiable in various, obvious aspects without departing from the cooling system and method as set forth and described in the following claims. Accordingly, the drawings and descriptions are to be regarded as exemplary in nature and not as restrictive.BRIEF DESCRIPTION OF THE DRAWING FIGURESThe accompanying drawing figures, which are incorporated herein by reference, illustrate various aspects of the cooling system and method, and together with the description, serve to explain certain principles of the invention. In the drawing figures, FIG. 1 is a schematic block diagram of the traction battery cooling system. FIG. 2 is a schematic block diagram of the control system for the cooling system shown in FIG. 1. FIG. 3 a is a control logic flow diagram illustrating an operation of a possible embodiment of the cooling system. FIG. 3 b is a detailed view of box 92 of the control logic flow chart shown in FIG. 3 a. FIG. 4 is a table indicating an HVAC load for a possible embodiment of the cooling system. FIG. 5 is a table illustrating four different stages or states of cooling device operation management for a possible embodiment of the cooling system based on load and evaporator variation.Reference will now be made in detail to the present preferred embodiments of the traction battery cooling system, examples of which are illustrated in the accompanying drawing figures.DETAILED DESCRIPTIONReference is now made to FIG. 1, which schematically illustrates the cooling system 10 implemented for an electrified motor vehicle, such as a hybrid electric vehicle or an electric vehicle. The cooling system 10 includes a coolant circuit 12 for circulating coolant between a traction battery 14 and a battery cooler 15 and / or a refrigerant-to-coolant cooling device 16 for heat exchange (refrigerant and coolant do not mix). The refrigerant may be a conventional refrigerant mixture such as water and ethylene glycol.The cooling system 10 also includes a refrigerant circuit generally designated by the reference numeral 18. The refrigerant circuit 18 circulates a refrigerant between an air conditioning compressor 20, an air conditioning condenser 22, and one or both of the two evaporators 24 1 or 24 2 and / or the cooling device 16. The refrigerant may be a conventional refrigerant such as R134a or R1234yf.As further shown in FIG. 1, the cooling system 10 also includes a plurality of flow control valves in the coolant circuit 12 and the refrigerant circuit 18. A battery coolant pump 36 circulates the coolant through one or both loops depending on the position of the battery coolant valve 26. a sensor 33 monitors the temperature of the coolant upstream of the traction battery 14.As further shown in FIG. 1, the second loop 34 includes a coolant bypass 35.Referring to the refrigerant circuit 18, the plurality of flow control valves further include a front evaporator refrigerant shut-off valve 38 between the air conditioning condenser 22 and the front evaporator 24 1, a rear evaporator refrigerant shut-off valve 40 between the condenser and the rear evaporator 24 2 and a refrigerant shut-off valve 41 between the condenser and the cooling device 16. Similarly, a second thermal expansion device 44 is provided in the refrigerant circuit 18 between the rear evaporator refrigerant shut-off valve 40 and the rear evaporator 24 in 2 manner. Further, a third thermal expansion device 46 is provided in the refrigerant circuit 18 between the refrigerant cut-off valve 41 and the cooling device 16. It should be understood that the evaporator refrigerant shut-off valve 38 and the first thermal expansion device 42 could be combined into one device if desired to minimize possible refrigerant leakage paths. Similarly, the refrigerant cut-off valve 40 could be combined with the second thermal expansion device 44 and the refrigerant cut-off valve 41 could be combined with the third thermal expansion device 46.As shown in FIG. 2, the cooling system 10 also includes a control system generally designated by the reference numeral 50. As shown, the control system 50 includes a controller 52. the controller 52 is a computing device such as a special purpose microprocessor or electronic control unit (ECU) that operates in accordance with suitable instructions provided by control software. Such a controller 52 may include one or more processors, one or more memories, and one or more network interfaces, all of which communicate with each other over a communication bus.The controller 52 is configured to (a) control operation of the plurality of flow control valves including, but not limited to, the battery coolant valve 26, the coolant proportional valve 37, and the refrigerant shut-off valves 38, 40, and 41, and (b) prioritize cabin cooling over traction battery cooling when the traction battery has a normal or acceptable operating temperature. To this end, the controller 52 is configured to include a first data input 54 connected to a sensor or other device 56, such as another controller, that provides data regarding ambient air temperature. The controller 52 is also configured to include a second data input 58 connected to a sensor or other device 60, such as another controller, to provide data input for an HVAC blower speed.As further shown, the controller 52 is further configured to include a third data input 62 connected to a sensor or device 64, such as another controller, that provides 1, 242 data regarding a temperature of the evaporators 24 (one sensor or device 64 per evaporator). The controller 52 is also configured to include a fourth data input 66 connected to a sensor or device 68, such as another controller, to provide data regarding the traction battery coolant temperature. Although not shown in FIG. 2, it should be appreciated that the controller 52 may include additional data inputs connected to other sensors or devices, including other controllers, that provide data input regarding other system operating parameters including, but not limited to, refrigerant pressure (see sensor 21 in FIG. 1 ), traction battery temperature, and cabin cooling requirements from the HVAC system of the motor vehicle.The controller 52 is generally configured to provide the cooling required for the traction battery 14 while consuming a minimum amount of motor vehicle energy. To this end, the controller 52 is configured to operate in three different battery cooling modes. In the first mode, which consumes the least amount of vehicle energy, the battery coolant valve 26 is in a position such that coolant in the coolant circuit 12 is circulated through the first loop 30 between the traction battery 14 and the battery cooler 15. Ambient air forced through the battery cooler 15 during vehicle movement serves to cool the coolant that is subsequently circulated back through the traction battery 14 by the battery coolant pump 36 to maintain a desired operating temperature of the traction battery. If the temperature of the traction battery 14 rises to a certain predetermined temperature, the controller 52 operates in a second cooling mode in which the fan 74 is activated to force cooling air through the battery cooler 15, thereby providing additional cooling to the coolant and the traction battery 14 through which the coolant is circulated.If the temperature of the traction battery 14 reaches a predetermined higher temperature when operating in the second cooling mode, the controller 52 initiates a third cooling mode by adjusting the battery coolant valve 26 to partially or fully direct the coolant through the second loop 34 such that the selected portion of the coolant flow, as determined by the position of the coolant proportional valve 37, is circulated between the traction battery 14 and the cooling device 16 using the battery coolant pump 36. In this mode, the controller 52 is configured to prioritize cabin cooling over traction battery cooling during normal motor vehicle operation when the cabin is also cooled.To this end, a method is provided for controlling traction battery cooling while limiting temperature variations of the conditioned air discharged into the interior of an electrified motor vehicle. The method includes the steps of: (a) prioritizing, by the controller 52, interior cooling over traction battery cooling based on an HVAC load and evaporator deviation, and (b) controlling a flow of battery coolant to the cooling device 16 using the coolant proportional valve 37. the method may further include the steps of: (a) monitoring, by a first device 56, an ambient air temperature, (b) monitoring, by a second device 60, an HVAC blower speed, and (c) monitoring, by a third device 64, an evaporator temperature. The controller 52 then determines an HVAC load based on an indicated HVAC blower speed and an indicated ambient temperature.More specifically, as shown in FIG. 3 a, the algorithm determines whether battery cooler capacity is available when the cooler 16 is requested, and thus determines how to control the coolant proportional valve 37. If the cooling device 16 is not available, it is assumed that the battery cooling is continued via the battery cooler 15. The method begins at box 76. In a first step, it is determined whether a cooling device request is present (box 78). If the chiller 16 is not requested, the algorithm returns to the beginning. If the cooling device request is present, the controller 52 proceeds to box 80 and determines / calculates an evaporator deviation (box 80) and an HVAC load (box 82). As shown in FIG. 4, the HVAC load is a function of ambient air temperature and HVAC blower speed and is therefore determined by the controller 52 based on data provided by the sensors or devices 56, 60 at the respective data inputs 54, 58. In the embodiment of the cooling system 10 shown in FIG. 4, an ambient temperature of 25 degrees Celsius and a blower speed percentage of 60% result in an HVAC load of 50.Evaporator deviation is determined by comparing the actual evaporator temperature indicated by the sensor or device 64 at the third data input 62 with a desired evaporator temperature stored in the controller 52.As shown in FIG. 3 a, the controller 52 then determines the cooling device climate capacity available for traction battery cooling (see box 84) as a function of the determined evaporator deviation and the HVAC load. FIG. 5 illustrates a function table for a particular embodiment of the cooling system 10. In this embodiment, an evaporator deviation of 3, 4, or 5 indicates that the cooling device 16 is not available for a stage of traction battery cooling (cooling device capacity state 0). In contrast, an evaporator deviation of 2 and a load of 30 indicate that the cooling device 16 is available for battery cooling at a minimum opening (cooling device capacity state 1). Further, an evaporator deviation of 0.5 and a load of 60 also indicate that the cooling device is available for reduced cooling of the traction battery 14 by the cooling device (cooling device capacity state 2). Finally, an evaporator deviation of 0 and a load of 50 indicate that a full stage of the cooling device 16 is available for traction battery cooling (cooling device capacity state 3).As shown in FIG. 3 a, the operating algorithm returns to the beginning when the cooling device's climate capacity is not available for cooling (box 86). In this situation, the battery temperature system continues cooling via the battery cooler 15 (with or without operation of the fan 74) and continues to request the cooling device 16. Once a chiller capacity becomes available, the battery temperature system proceeds to chiller 16. In other words, there are times when the battery cooling mode may request the cooling device 16 but continues to operate the first loop 30.In contrast, in box 88, when evaporator cooling is available for the traction battery 14, the controller 52 transmits the available cooling device air conditioning capacity at the appropriate maximum position of the coolant proportional valve 37. in the embodiment depicted in FIG. 3 a, when the indicated cooling device capacity is at a minimum, the controller 52 may open the coolant proportional valve 37 in the coolant circuit 12 at a maximum opening of 25% (cooling device capacity state 1) to allow the coolant to flow through the cooling device 16 for heat exchange with the refrigerant in the refrigerant circuit 18 and cooling the traction battery 14. In contrast, when the cooling device 16 is available to the reduced stage as determined in FIG. 5, the controller 52 calculates a maximum opening signal for the coolant proportional valve 37 of 50% (cooling device capacity state 2), thereby enabling a maximum increase in the flow of coolant to the cooling device 16 for heat exchange with the refrigerant and cooling the traction battery 14.If both indoor and battery cooling are required (box 90 and box 91), the valve position control algorithm is initiated (box 92). The algorithm for determining valve position is a control algorithm that opens the coolant proportional valve 37 based on a battery coolant temperature. In the step shown above, a maximum valve opening is calculated based on the air conditioning capacity of the cooling device. The valve opens in proportion to the available cooling device capacity. It will also be appreciated that the stated opening percentages are given for purely exemplary purposes and that the coolant proportional valve 37 may provide a full opening range of 0% to 100%.Once controller 52 determines the available cooling device capacity (cooling device capacity state 3), the position of coolant proportional valve 37 is determined in box 92 (see FIGS. 3 aand 3 b ). Thus, the controller 52 implements a PI control of the battery coolant temperature (box 94) to control the coolant temperature in the traction battery 14. The coolant proportional valve 37 makes adjustments (box 96) based on the controller calculated battery coolant temperature deviation (box 98) determined by comparing the actual or indicated battery coolant temperature (box 100) with the controller stored desired battery coolant temperature (box 102).The PI control is continuously executed in the controller 52, but in the cooling device capacity states 1 and 2, the maximum limitation of the position of the refrigerant proportional valve 37 based on the air conditioning capacity of the cooling device is applied (box 104), thereby limiting the opening position of the refrigerant proportional valve 37 (box 106). The controller 52 also controls the speed of the air conditioner compressor 20 based on the evaporator deviation (box 108). See Figure 3a.In contrast, if the HVAC system is not used for indoor cooling as determined in box 90, the cooling system 10 operates in battery-only cooling mode (box 110). See Figure 3a. In this mode, the controller 52 fully opens the refrigerant proportional valve 37 to the cooling device 16 (box 112) and controls the speed of the air conditioner compressor 20 based on the battery refrigerant temperature deviation (box 114).Advantageously, the controller 52 may regulate the flow of coolant to the cooling device 16 at any time. As a result, the traction battery cooling can be started smoothly via the cooling device 16 and can be carried out continuously without any effects on the interior space. As a result, adverse variations in the temperature of the conditioned air passing through the evaporators 24 in 1, 242 and later discharged into the interior space are minimized. The cooling system 10 and the associated method prioritize indoor cooling by delaying the cooling device start and also provide a method of operating at reduced cooling capacity to maintain indoor comfort under changing climate capacity conditions. Only under extreme operating conditions where the traction battery temperatures increase to predetermined critical levels does the controller 52 prioritize battery cooling over cabin cooling by first providing the cooling device 16 with full climate capacity for traction battery cooling and remaining climate capacity for the cabin.The foregoing is for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. In light of the above teachings, obvious modifications and variations are possible. All such modifications and variations are within the scope of the appended claims when interpreted according to the breadth to which they are entitled, juristically and fairly, according to the rules.Explanation of CharactersFIG. 3 a 76 Start 78 Cooling device requirement true? - No + Yes 80 Evaporator deviation calculate 82 Load calculate 84 Available air conditioning capacity of the cooling device = Spark. (Load, Evaporator Deviation) 86 Available Cooling Device Air Conditioning Capacity >0 88 Max. Limiting valve position based on capacity cooler capacity state = minimum = 1 -> refrigerant proportional valve to 25% open cooler capacity state = reduced = 2 -> refrigerant proportional valve to 50% open cooler capacity state = full = 3 -> refrigerant proportional valve open based on battery refrigerant deviation = desired battery inlet refrigerant temperature - actual battery inlet refrigerant temperature 90 indoor cooling true? 91 indoor and battery cooling 92 valve position controller 108 compressor speed based on evaporator deviation 110 only battery cooling 112 refrigerant proportional valve to fully open position to cooling device 114 compressor speed based on battery refrigerant temperature deviation

Claims

A cooling system (10) for an electrified motor vehicle, comprising: a coolant circuit (12) circulating coolant between a traction battery (14) and a battery cooler (15) or cooling device (16); a refrigerant circuit (18) circulating coolant between an air conditioning compressor (20), an air conditioning condenser (22), and a first evaporator (24 1) or the cooling device (16); a plurality of flow control valves in the coolant circuit (12) and the refrigerant circuit (18); and a control system (50) comprising a controller (52) configured to (a) control operation of the plurality of flow control valves and (b) prioritize indoor cooling over traction battery cooling when the traction battery (14) has a normal operating temperature; wherein the coolant circuit (12) further comprises a coolant bypass (35) and the plurality of flow control valves comprise a coolant proportional valve (37) in the coolant circuit (12) between the traction battery (14) and the cooling device (16) for controlling a flow of the coolant through the cooling device (16), wherein the controller (52) is configured to determine a maximum open position of the coolant proportional valve (37) as a function of the air conditioning capacity of the cooling device (16), wherein the controller (52) is configured to determine a target open position of the coolant proportional valve (37) as an output of a PI control of the battery coolant temperature and to determine a final open position of the coolant proportional valve (37) as a function of the maximum open position of the coolant proportional valve (37) and the target open position of the coolant proportional valve (37).A cooling system (10) for an electrified motor vehicle, comprising: a coolant circuit (12) circulating coolant between a traction battery (14) and a battery cooler (15) or cooling device (16); a refrigerant circuit (18) circulating coolant between an air conditioning compressor (20), an air conditioning condenser (22), and a first evaporator (24 1) or the cooling device (16); a plurality of flow control valves in the coolant circuit (12) and the refrigerant circuit (18); and a control system (50) comprising a controller (52) configured to (a) control operation of the plurality of flow control valves and (b) prioritize indoor cooling over traction battery cooling when the traction battery (14) has a normal operating temperature; wherein the coolant circuit (12) further comprises a coolant bypass (35) and the plurality of flow control valves comprise a coolant proportional valve (37) in the coolant circuit (12) between the traction battery (14) and the cooling device (16) for controlling a flow of the coolant through the cooling device (16), wherein the control system (50) comprises a first device configured to monitor an ambient air temperature, a second device configured to monitor an HVAC blower speed, and a third device configured to monitor an evaporator temperature.A cooling system (10) for an electrified motor vehicle, comprising: a coolant circuit (12) circulating coolant between a traction battery (14) and a battery cooler (15) or cooling device (16); a refrigerant circuit (18) circulating coolant between an air conditioning compressor (20), an air conditioning condenser (22), and a first evaporator (24 1) or the cooling device (16); a plurality of flow control valves in the coolant circuit (12) and the refrigerant circuit (18); and a control system (50) comprising a controller (52) configured to (a) control operation of the plurality of flow control valves and (b) prioritize indoor cooling over traction battery cooling when the traction battery (14) has a normal operating temperature; wherein the coolant circuit (12) further comprises a coolant bypass (35) and the plurality of flow control valves comprise a coolant proportional valve (37) in the coolant circuit (12) between the traction battery (14) and the cooling device (16) for controlling a flow of the coolant through the cooling device (16), wherein the controller (52) is configured to determine an HVAC load based on an indicated HVAC blower speed and an indicated ambient air temperature.The refrigeration system (10) of any of claims 1 and 3, wherein the control system (50) further comprises an ambient temperature sensor and an evaporator temperature sensor.The cooling system (10) of any of claims 1 to 4, wherein the plurality of flow control valves comprises a battery coolant valve (26) in the coolant circuit (12) downstream of the traction battery (14) and upstream of (a) the battery cooler (15) and (b) the coolant proportional valve (37) for controlling a flow of the coolant from the traction battery (14) to the battery cooler (15) or the coolant proportional valve (37).The refrigeration system (10) of any of claims 1 to 5, wherein the plurality of flow control valves comprise a thermal expansion device in the refrigerant circuit (18) between the air conditioning condenser (22) and the refrigeration device (16) for controlling a flow of the refrigerant from the air conditioning condenser (22) into the refrigeration device (16).The cooling system (10) of any of claims 1 to 6, wherein the controller (52) is configured to include a fourth data input (66) for a traction battery temperature.The cooling system (10) of any of claims 1 to 7, wherein the controller (52) is configured to include a fifth data input for a coolant temperature.The cooling system (10) of any of claims 1 to 8, wherein the control system (50) further comprises a traction battery temperature sensor and a coolant temperature sensor.A method for controlling traction battery cooling while limiting temperature variations of conditioned air discharged into an interior of an electrified motor vehicle, comprising: prioritizing, by a controller (52), interior cooling over traction battery cooling based on an HVAC load and an evaporator deviation; Controlling a flow of battery coolant to a cooling device (16) using a coolant proportional valve (37) controlled by the controller (52), further comprising determining, by the controller (52), a maximum opening position of the coolant proportional valve (37) as a function of the air conditioning capacity of the cooling device (16), further comprising determining, by the controller (52), a target opening position of the coolant proportional valve (37) as an output of a PI control of the battery coolant temperature and determining, by the controller (52), a final opening position of the coolant proportional valve (37) as a function of the maximum opening position of the coolant proportional valve (37) and the target opening position of the coolant proportional valve (37).A method for controlling traction battery cooling while limiting temperature variations of conditioned air discharged into an interior of an electrified motor vehicle, comprising: prioritizing, by a controller (52), interior cooling over traction battery cooling based on an HVAC load and an evaporator deviation; and controlling a flow of battery coolant to a cooling device (16) using a coolant proportional valve (37) controlled by the controller (52), further comprising: monitoring, by a first device, an ambient air temperature; monitoring, by a second device, an HVAC blower speed; monitoring, by a third device, an evaporator temperature.A method for controlling traction battery cooling while limiting temperature variations of conditioned air discharged into an interior of an electrified motor vehicle, comprising: prioritizing, by a controller (52), interior cooling over traction battery cooling based on an HVAC load and an evaporator deviation; and controlling a flow of battery coolant to a cooling device (16) using a coolant proportional valve (37) controlled by the controller (52), comprising determining, by the controller (52), an HVAC load based on an indicated HVAC blower speed and an indicated ambient air temperature.The method of any of claims 10 to 12, further comprising (a) determining, by the controller (52), an evaporator deviation by comparing an indicated evaporator temperature to a desired evaporator temperature, and (b) determining, by the controller (52), an air conditioning capacity of the cooling device (16) as a function of evaporator deviation and HVAC load.The method of any of claims 10 to 13, further comprising monitoring, by a fourth device, a traction battery temperature.The method of any of claims 10 to 14, comprising calculating, by the controller (52), a target traction battery coolant temperature based on a battery temperature.The method of any of claims 10 to 15, further comprising controlling, by the controller (52), a flow of coolant to the cooling device (16) based on an indicated traction battery temperature as compared to a desired traction battery temperature.The method of any of claims 11 to 16, further comprising determining, by the controller (52), a maximum open position of the refrigerant proportional valve (37) as a function of the air conditioning capacity of the cooling device (16).The method of any of claims 11 to 17, further comprising determining, by the controller (52), a desired opening position of the coolant proportional valve (37) as an output of a PI control of the battery coolant temperature and determining, by the controller (52), a final opening position of the coolant proportional valve (37) as a function of the maximum opening position of the coolant proportional valve (37) and the desired opening position of the coolant proportional valve (37).The method of any of claims 10 to 18, further comprising fully opening, by the controller (52), the coolant proportional valve (37) to the cooling device (16) and controlling, by the controller (52), a compressor speed based on a battery coolant temperature deviation when operating in the battery-only cooling mode.

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