System and method for heating an electric vehicle

Abstract

The present disclosure relates to systems and methods for heating an electric vehicle. An exemplary electric vehicle includes a passenger compartment and an infrared heater configured to radiate heat to condition the passenger compartment. The vehicle further includes a heating device configured to heat airflow to condition the passenger compartment. Furthermore, the vehicle includes a controller configured to selectively command a change in the output of the heating device based on the amount of power available to the infrared heater.

Description

Technical Field

[0001] The present disclosure relates to systems and methods for heating an electric vehicle. An exemplary electric vehicle includes a passenger compartment conditioned by an infrared heater configured to radiate heat and a heating device configured to heat airflow. Background Art

[0002] The need to reduce automotive fuel consumption and emissions is well known. Consequently, vehicles are being developed with the goal of reducing reliance on internal combustion engines. Electric vehicles are one type of vehicle developed for this purpose. Generally, electric vehicles differ from conventional motor vehicles in that they are selectively powered by one or more battery-powered electric motors. In contrast, conventional motor vehicles rely solely on internal combustion engines for propulsion.

[0003] Electric vehicles often present unique thermal management challenges. For example, achieving the desired level of passenger cabin comfort within an electric vehicle must be balanced with maximizing fuel economy and the range of the electric vehicle. Summary of the Invention

[0004] According to an exemplary aspect of the present invention, an electric vehicle includes, among other things, a passenger compartment, an infrared heater configured to radiate heat to condition the passenger compartment, a heating device configured to heat airflow to condition the passenger compartment, and a controller. The controller is configured to selectively command a change in the output of the heating device based on an amount of power available to the infrared heater.

[0005] In a further non-limiting embodiment of the foregoing vehicle, the heating device is controlled based on a target value, and the controller is configured to selectively vary the target value based on an amount of power available to the infrared heater.

[0006] In a further non-limiting embodiment of any of the foregoing vehicles, the controller is configured to selectively reduce the target value when sufficient power is available to the infrared heater.

[0007] In a further non-limiting embodiment of any of the foregoing vehicles, the controller is configured to gradually decrease the target value when sufficient power is available to the infrared heater.

[0008] In a further non-limiting embodiment of any of the foregoing vehicles, the heating device includes a heater core fed by coolant, and the target value is a temperature of the coolant at an inlet of the heater core.

[0009] In a further non-limiting embodiment of any of the foregoing vehicles, the heating device includes an air heater, and the target value is an amount of power consumed by the air heater.

[0010] In a further non-limiting embodiment of any of the foregoing vehicles, the heating device includes an air heater, and the target value is an exhaust air temperature.

[0011] In a further non-limiting embodiment of any of the foregoing vehicles, the heating device is a coolant heater, and wherein the target value is a coolant temperature.

[0012] In a further non-limiting embodiment of any of the foregoing vehicles, the controller is configured to selectively vary the output of the heating device based on an amount of power available to the infrared heater, a temperature of the passenger compartment, and an occupancy level of the passenger compartment.

[0013] In a further non-limiting embodiment of any of the foregoing vehicles, the infrared heater is one of a plurality of infrared heaters configured to radiate heat to condition the passenger compartment.

[0014] In a further non-limiting embodiment of any of the foregoing vehicles, the infrared heater is powered by a DC / DC converter.

[0015] According to an exemplary aspect of the invention, a method includes, among other things, conditioning a passenger cabin of a vehicle by radiating heat with an infrared heater and heating an airflow with a heating device, and varying an output of the heating device based on an amount of power available to the infrared heater.

[0016] In a further non-limiting embodiment of the foregoing method, the method includes controlling the heating device based on a target value and varying the target value based on an amount of power available to the infrared heater.

[0017] In a further non-limiting embodiment of any of the foregoing methods, the method further includes decreasing the target value when sufficient power is available to the infrared heater.

[0018] In a further non-limiting embodiment of any of the foregoing methods, the method further includes gradually decreasing the target value when sufficient power is available to the infrared heater.

[0019] In a further non-limiting embodiment of any of the foregoing methods, the heating device includes a heater core fed by coolant, and wherein the target value is a temperature of the coolant at an inlet of the heater core.

[0020] In a further non-limiting embodiment of any of the foregoing methods, the heating device comprises an air heater, and wherein the target value is an amount of power consumed by the air heater.

[0021] In a further non-limiting embodiment of any of the foregoing methods, the heating device comprises an air heater, and wherein the target value is an exhaust air temperature.

[0022] In a further non-limiting embodiment of any of the foregoing methods, the heating device is a coolant heater, and wherein the target value is a coolant temperature.

[0023] In a further non-limiting embodiment of any of the foregoing methods, the method further includes varying an output of the heating device based on an amount of power available to the infrared heater, a temperature of the passenger compartment, and an occupancy level of the passenger compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 schematically illustrates a powertrain system for an electric vehicle;

[0025] Figure 2 A vehicle system of an electric vehicle is shown;

[0026] Figure 3 A top view of a vehicle is shown, and a plurality of infrared heaters within the vehicle are shown;

[0027] Figure 4 An exemplary control strategy for controlling an infrared heater and a heating device configured to heat an air flow is shown. Figure 4 In the embodiment, the heating device is a heater core controlled based on a coolant inlet target temperature;

[0028] Figure 5 An exemplary control strategy for controlling an infrared heater and a heating device configured to heat an air flow is shown. Figure 5 In the embodiment, the heating device is an air heater controlled based on the amount of power consumed by the air heater;

[0029] Figure 6 An exemplary control strategy for controlling an infrared heater and a heating device configured to heat an air flow is shown. Figure 6 In the case of a condenser, the heating device is an air heater controlled based on the exhaust air temperature;

[0030] Figure 7 An exemplary control strategy for controlling an infrared heater and a heating device configured to heat an air flow is shown. Figure 7 In the embodiment, the heating device is a coolant heater which is controlled based on the coolant temperature. DETAILED DESCRIPTION

[0031] The present disclosure relates to systems and methods for heating an electric vehicle. An exemplary electric vehicle includes a passenger compartment and an infrared heater configured to radiate heat to condition the passenger compartment. The vehicle further includes a heating device configured to heat an airflow to condition the passenger compartment. Further, the vehicle includes a controller configured to selectively command a change in the output of the heating device based on the amount of power available to the infrared heater. In this manner, the vehicle uses the infrared heater to provide localized heating to vehicle occupants, which increases comfort while also reducing the load on the heating device, which in turn improves vehicle efficiency and, in the case of a battery electric vehicle (BEV), extends vehicle range.

[0032] With reference to the accompanying drawings, Figure 1 Schematically illustrated is a powertrain 10 for an electric vehicle 12. Although described as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and may extend to other electric vehicles including, but not limited to, plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs).

[0033] In a non-limiting embodiment, the powertrain 10 is a power split powertrain that utilizes a first drive system and a second drive system. The first drive system includes a combination of an engine 14 and a generator 18 (i.e., a first electric machine). The second drive system includes at least a motor 22 (i.e., a second electric machine), the generator 18, and a battery pack 24. In this example, the second drive system is considered to be the electric drive system of the powertrain 10. The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels 28 of the electric vehicle 12. Although Figure 1 A power-split configuration is depicted in FIG, but the present disclosure extends to any hybrid or electric vehicle, including full hybrid electric vehicles, parallel hybrid electric vehicles, series hybrid electric vehicles, mild hybrid electric vehicles, micro hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles.

[0034] The engine 14, which in one embodiment is an internal combustion engine, and the generator 18 can be connected via a first power transfer unit 30, such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, can be used to connect the engine 14 to the generator 18. In a non-limiting embodiment, the power transfer unit 30 is a planetary gear set including a ring gear 32, a sun gear 34, and a carrier assembly 36.

[0035] Generator 18 can be driven by engine 14 through power transfer unit 30 to convert kinetic energy into electrical energy. Alternatively, generator 18 can function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to shaft 38 connected to power transfer unit 30. Because generator 18 is operatively connected to engine 14, the speed of engine 14 can be controlled by generator 18.

[0036] The ring gear 32 of the power transfer unit 30 can be connected to a shaft 40, which is connected to the vehicle drive wheels 28 via a second power transfer unit 44. The second power transfer unit 44 can include a gear set having a plurality of gears 46. In other examples, other power transfer units may be suitable. The gears 46 transfer torque from the engine 14 to a differential 48, which ultimately provides traction to the vehicle drive wheels 28. The differential 48 can include a plurality of gears that enable torque to be transferred to the vehicle drive wheels 28. In one example, the second power transfer unit 44 is mechanically connected to an axle 50 via the differential 48, thereby distributing torque to the vehicle drive wheels 28.

[0037] The motor 22 can also be used to drive the vehicle drive wheels 28 by outputting torque to a shaft 54 ​​that is also connected to the second power transfer unit 44. In one embodiment, the motor 22 and the generator 18 cooperate as part of a regenerative braking system, in which both the motor 22 and the generator 24 can be used as motors to output torque. In another example, the motor 22 and the generator 18 can each output electrical energy to the battery pack 14.

[0038] Battery pack 24 is an exemplary electric vehicle battery. Battery pack 24 may be a high-voltage traction battery pack that includes a plurality of battery assemblies 25 (i.e., a battery array or grouped battery cells) that are capable of outputting power to operate motor 22, generator 18, and / or other electrical loads of electric vehicle 12. Other types of energy storage devices and / or output devices may also be used to power electric vehicle 12.

[0039] In a non-limiting embodiment, the electric vehicle 12 has two basic operating modes. The electric vehicle 12 can operate in an electric vehicle (EV) mode, in which the motor 22 (typically without assistance from the engine 14) is used for vehicle propulsion, thereby depleting the state of charge of the battery pack 24 to its maximum allowable discharge rate under certain driving modes / cycles. The EV mode is an example of a charge-depleting operating mode of the electric vehicle 12. During EV mode, the state of charge of the battery pack 24 can increase under certain circumstances, such as during regenerative braking. The engine 14 is typically off in the default EV mode, but can be operated as needed based on vehicle system conditions or with operator permission.

[0040] In addition, the electric vehicle 12 can operate in a hybrid electric vehicle (HEV) mode, in which both the engine 14 and the motor 22 are used for vehicle propulsion. The HEV mode is an example of a charge-maintaining operating mode for the electric vehicle 12. During the HEV mode, the electric vehicle 12 can reduce the propulsion use of the motor 22 in order to maintain the state of charge of the battery pack 24 at a constant or approximately constant level by increasing the propulsive force of the engine 14. In addition to the EV and HEV modes within the scope of the present disclosure, the electric vehicle 12 can also operate in other operating modes.

[0041] To improve the fuel economy and overall efficiency of the electric vehicle 12, the engine 14 may be downsized and operated at a higher efficiency, potentially reducing the vehicle's warm-up capability. Therefore, a system and method for actively compensating for this reduced heat generated by the engine 14 is described in detail below.

[0042] Figure 2 is a vehicle that can be used in electric vehicles (e.g. Figure 1 A highly schematic diagram of a vehicle system 54 for use within an electric vehicle 12 (e.g., an electric vehicle 12). Various components of the vehicle system 54 are shown schematically to better illustrate features of the present disclosure. However, these components are not necessarily depicted in their exact locations in an actual vehicle and are not necessarily shown to scale.

[0043] The vehicle system 54 is adapted to deliver a conditioned air flow 74-1 at a desired temperature to the passenger compartment 56 of the electric vehicle 12. In a non-limiting embodiment, the heating device H is controlled to increase the temperature of the conditioned air flow 74-1 delivered to the passenger compartment 56. In one specific embodiment, such as in a PHEV, the heating device H is controlled to increase the temperature of the conditioned air flow 74-1 delivered to the passenger compartment 56 via the heater core 70, which transfers heat from the heat source 14', which may be the engine 14, via the engine coolant C circulating between the heat source 14' and the heater core 70. In another embodiment, such as in a BEV, the heat source 14' is provided by a coolant heater, which may be electric. The coolant heater heats the coolant circulating between the coolant heater and the heater core 70. Although Figure 2 , both the electric heater 58 and the heater core 70 are shown, but it should be understood that in some examples, the heating device H may include only one of the electric heater 58 and the heater core 70. Alternatively, the heating device H may include both the electric heater 58 and the heater core 70, both of which may be used simultaneously to increase the temperature of the conditioned airflow 74-1.

[0044] An exemplary vehicle system 54 may include a heating, ventilation, and air conditioning (HVAC) system 60, a heat source 14', a heater H, a DC / DC converter 62, a battery pack 24, and a controller 64. The HVAC system 60 is configured to regulate the temperature within the passenger compartment 56. In a non-limiting embodiment, the HVAC system 60 includes an HVAC housing 66, in which the heater H and an evaporator 72 are housed, and a blower 68. The blower 68 can be controlled to force an airflow 74 through the HVAC housing 66 and into the passenger compartment 56. In a non-limiting embodiment, the blower 68 is a variable speed blower for forcing the airflow 74 through the HVAC housing 66, through various heating and cooling elements, and then into the passenger compartment 56.

[0045] In one example, if heating is required within the passenger compartment 56 (e.g., by the driver / operator / passenger), the coolant C heated by the heat source 14' flows to the heater core 70 to exchange heat with the airflow 74 blown through the heater core 70 by the blower 68. For example, the airflow 74 may enter the HVAC housing 66 from outside the vehicle. The relatively warm coolant C from the heat source 14' loses its heat to the airflow 74 within the heater core 70, and the conditioned airflow 74-1 then flows into the passenger compartment 56, thereby heating the passenger compartment 56.

[0046] In another example, the airflow 74 heated by the heater core 70 can be additionally heated by activating the electric heater 58. In yet another example, the heater core 70 is not present and the airflow 74 is heated solely by the electric heater 58. As examples, the electric heater 58 can be a positive temperature coefficient (PTC) heater or a resistive heating device. Further, the electric heater 58 can be a low voltage device or a high voltage device and can be selected so that its maximum regulation temperature is within the optimal comfort level temperature range for the passenger compartment 56. Although Figure 2 A single electric heater 58 is shown, but it should be understood that the vehicle system 54 may include one or more electric heaters 58 .

[0047] The electric heater 58 may be mounted at various locations within the HVAC housing 66. For example, in a non-limiting embodiment, the electric heater 58 is positioned between the heater core 70 and the passenger compartment 56. Other mounting locations are also contemplated within the scope of the present disclosure.

[0048] In a first non-limiting embodiment, for example, when the electric heater 58 is a high-voltage device, the first DC output 75 from the battery pack 24 can be used to power the electric heater 58. In a second non-limiting embodiment, for example, when the electric heater 58 is a low-voltage device, the second DC output from the DC / DC converter 62 can be used to power the electric heater 58. For example, the first DC output 75 from the battery pack 24 can be received by the DC / DC converter 62. The DC / DC converter 62 can be configured as a step-down converter that changes the first DC output 75 from the battery pack 24 from one voltage level to another, lower voltage level. Subsequently, the second DC output 76 from the DC / DC converter 62 is used to power the electric heater 58.

[0049] The controller 64 may be programmed with executable instructions for interfacing with and operating the various components of the vehicle system 54. The controller 64 includes various inputs and outputs for interfacing with the components of the vehicle system 54, including but not limited to the HVAC system 60, the heat source 14', the battery pack 24, the DC / DC converter 62, and the electric heater 58. The controller 64 further includes a processing unit and non-transitory memory for executing various control strategies and modes of the vehicle system 54.

[0050] In a non-limiting embodiment, the controller 64 controls the HVAC system 60 to heat the passenger compartment 56 to a desired comfort level. In the present disclosure, the passenger compartment 56 includes a plurality of infrared heaters 80 that are configured to provide localized heating within the passenger compartment 56, which in turn can reduce the load on the HVAC system 60 to achieve the same level of passenger comfort. The infrared heaters 80 can be low-voltage devices powered by the output of the DC / DC converter 62, or they can be high-voltage devices powered by the output of the battery pack 24. The controller 64 is configured to selectively activate one or more infrared heaters 80 to provide radiant heat at desired locations within the passenger compartment 56.

[0051] The infrared heater 80 may be any known type of infrared heater configured to radiate heat. The infrared heater 80 is used to provide localized heating directly to the passengers of the vehicle to improve passenger comfort and thereby reduce the load on the heating device H.

[0052] Figure 3 A top perspective view of an exemplary electric vehicle 12 is shown, and specifically three infrared heaters 80 are shown. The controller 64 is configured to selectively activate each infrared heater 80, including selectively turning the infrared heater 80 on and off, and varying the output level of the infrared heater 80. Figure 2 and Figure 3Three infrared heaters 80 are shown, but it should be understood that the present disclosure extends to vehicles having one or more infrared heaters. Further, the infrared heaters 80 do not need to be as Figure 3 As shown, the infrared heater 80 is placed in the passenger compartment 56, so long as the radiant heat from the infrared heater 80 can be directed to the occupants of the vehicle. Figure 3 Infrared heater 80 is shown in exemplary locations, and the present disclosure extends to vehicles having infrared heater 80 in locations other than those shown.

[0053] The controller 64 is configured to selectively vary the output of the heating device H based on the amount of power available to the one or more infrared heaters 80. That is, during operation of the vehicle 12, the amount of power available, for example, from the DC / DC converter, may vary depending on certain vehicle conditions. If sufficient power is available to the infrared heaters 80, they may operate, and the target control value (e.g., power) for the heating device H may be shifted, thereby reducing system load and improving efficiency. For example, in the case of a BEV, the reduced system load ultimately extends the range of the electric vehicle 12 by, for example, reducing the power consumption of the electric coolant heaters due to the reduced system load.

[0054] As described above, the present disclosure contemplates many different heating devices H. Different heating devices H are controlled to produce outputs based on different target control values ​​(e.g., "target values" or "targets"). For example, when the heating device H is the heater core 70, the target control value may be the heater core coolant inlet temperature. When the heating device H is the electric heater 58, the target control value may be the amount of power consumed by the electric heater 58. Figure 4-7 Describe these and more examples.

[0055] Figure 4 A method according to the present disclosure is schematically illustrated as embodied in a control strategy 100 for controlling a vehicle system 54 . Figure 4 Specifically, the present invention relates to a vehicle system 54 in which the heating device H is a heater core, such as heater core 70. A control strategy 100 includes varying the output of the heating device H based on the amount of power available to one or more infrared heaters 80. The controller 64 may be programmed with one or more algorithms suitable for executing the control strategy 100 or any other control strategy. In a non-limiting embodiment, the control strategy 100 is stored as executable instructions in a non-transitory memory of the controller 64.

[0056] The control strategy 100 begins at block 102. At block 104, the control strategy 100 undergoes a series of calculations to determine the amount of power available to power the infrared heater 80. In this example, the amount of power available to the infrared heater 80 can be obtained by subtracting the used DC / DC power from the available DC / DC power.

[0057] Based on these factors, at block 106, the control strategy 100 determines whether the DC / DC power available to the infrared heater 80 is sufficient to operate the infrared heater 80. Whether the power is sufficient can be based on a minimum value of the power values ​​required for known operation. If the available power is sufficient for operation, the control strategy continues to block 108.

[0058] At box 108, the control strategy 100 determines the load on the HVAC system 60, including inputs 110 such as the desired passenger cabin temperature, the intake temperature of the airflow 74, the vehicle occupancy, and the flow rate of the blower 68. The load on the HVAC system 60 may also be determined by referencing a lookup table stored in the memory of the controller 64.

[0059] At this point in the control strategy 100, the present disclosure varies based on the type of heating device H in the vehicle system 54 and how the heating device (or devices) H are controlled. Specifically, the heating device H is a specific heating device that is controlled based on a target value, and the control strategy 100 selectively changes the target value to reduce the overall load on the system. Likewise, in Figure 4 In the example of FIG, the heating device specific portion of the control strategy 112 relates to the vehicle system 54 including the heater core 70 controlled based on a target value, which is the temperature of the coolant C at the inlet of the heater core 70. Although in Figure 5-7 , but each control strategy is configured to selectively change the target value of the heating device H, and thereby change the output of the heating device H, based on the amount of power available to the infrared heater 80. Specifically, the control strategy 100 is configured to reduce the target value of the heating device H when sufficient power is available to the infrared heater 80.

[0060] exist Figure 4 In block 114A, the control strategy 100 determines a base target value for coolant C entering the heater core 70 . For example, the base target value is determined based on the determination in block 108 .

[0061] At block 116A, the control strategy then determines an offset from the base target value based on the available power to the infrared heater 80 obtained at block 104. In this example, the offset is a decrease in the temperature of the coolant C at the inlet of the heater core. By reducing the required coolant inlet temperature of the heater core 70, the load on the HVAC system 60 is reduced. The offset can be determined based on the load on the HVAC system 60 obtained at block 108 and the available power to the infrared heater obtained at block 104. The offset can be proportional to the amount of power available to the infrared heater 80. For example, if a relatively large amount of power is available to the infrared heater 80, the offset may be relatively large.

[0062] Next, at block 118 , a modified target value for the heater core coolant inlet temperature is determined by subtracting the offset (obtained at block 116A) from the base value (obtained at block 114A).

[0063] At block 120 , the base target value is gradually changed by an offset amount, sometimes referred to as a gap-to-target amount, until the base target reaches the modified target value. Gradually changing the base target value over time prevents undesirable vehicle behavior, such as rapid changes in engine operation or rapid changes in passenger compartment 56 temperature. The gradual change can be a linear change between the base target value and the modified target value. Alternatively, the gradual change can be a series of relatively small incremental changes over time or some other transition method, where the transition can be smoothed by nonlinear means, such as various types of signal filtering.

[0064] At block 122, power to the infrared heaters 80 is set, and at block 124, the number of infrared heaters 80 to be operated is determined based on the vehicle occupancy and the power set at block 122. At block 126, power is distributed to the IR heaters, and the infrared heaters 80 are operated according to the determinations made at blocks 122 and 124.

[0065] Figure 5-7 The control strategy 100 is shown when applied to different heating devices H. Figure 5-7 In the control strategy and about Figure 4 The description is essentially the same, with changes only occurring in the thermal device specific portion 112 .

[0066] Figure 5The control strategy 100 is shown when the heating device H is an air heater controlled based on a target value for the amount of power consumed by the air heater. The air heater can be provided by an electric heater, such as electric heater 58. At block 114B, the control strategy 100 determines a base target amount of power to be consumed by the air heater based on the determination made in block 108, and then determines an offset to that amount at block 116B. At block 114B, the base target amount of power can be determined based on a lookup table that correlates power consumption with the temperature of the conditioned airflow 74-1, or by directly calculating the temperature of the conditioned airflow. The offset from block 116B can be determined based on the amount of power available to the infrared heater 80, as determined in block 104, and other factors that influence the climate load, as described above.

[0067] Figure 6 FIG. 1 shows a control strategy 100 when the heating device H is an air heater controlled based on a target value of the exhaust air temperature. Figure 5 Likewise, air heating may be provided by an electric heater, such as electric heater 58. Figure 5 Involving target values ​​for power consumption, but in Figure 6 In , the air heater is controlled based on the sensed or derived temperature of the conditioned airflow 74 - 1 . Figure 6 In block 114C, the control strategy 100 determines a base target value for the exhaust air temperature based on the decision in block 108. In block 116C, the control strategy 100 then determines an offset to the target value based on the decision in block 104.

[0068] Figure 7 The control strategy 100 is shown when the heating device H is a coolant heater, which can be an electric coolant heater or other type of coolant heater controlled based on coolant temperature. In this example, the control strategy 100 determines a base target value for the temperature of the coolant C at block 114D based on the decision at block 108. At block 116D, the control strategy 100 determines an offset to the target value based on the decision at block 104.

[0069] It should be understood that terms such as "about," "substantially," and "typically" are not intended to be open-ended terms, and should be interpreted consistent with how those terms are interpreted by those skilled in the art.

[0070] Although the different examples have specific components shown in the drawings, the embodiments of the present disclosure are not limited to only those specific combinations. It is possible to use some components or features from one of the examples in combination with components or features from any other example.

[0071] It should be understood by those skilled in the art that the above embodiments are exemplary and non-restrictive, that is, the present disclosure may be modified within the scope of the claims. Therefore, the scope of their legal protection should be determined by studying the following claims.

Claims

1. An electric vehicle comprising: passenger compartment; an infrared heater configured to radiate heat to condition the passenger compartment; a heating device configured to heat an air flow to condition the passenger compartment; as well as a controller configured to selectively command a change in the output of the heating device based on the amount of power available to the infrared heater, wherein the heating device is controlled based on a target value, and wherein the controller is configured to selectively reduce the target value when sufficient power is available for the infrared heater.

2. The electric vehicle according to claim 1, wherein: The controller is configured to gradually decrease the target value when sufficient power is available for the infrared heater.

3. The electric vehicle according to claim 1 or 2, wherein: The heating device includes a heater core supplied by a coolant, and wherein the target value is a temperature of the coolant at an inlet of the heater core.

4. The electric vehicle according to claim 1 or 2, wherein: The heating device includes an air heater, and wherein the target value is the amount of power consumed by the air heater.

5. The electric vehicle according to claim 1 or 2, wherein: The heating device includes an air heater, and wherein the target value is an exhaust air temperature.

6. The electric vehicle according to claim 1 or 2, wherein: The heating device is a coolant heater, and wherein the target value is a coolant temperature.

7. The electric vehicle according to claim 1 or 2, wherein: The controller is configured to selectively vary the output of the heating device based on the amount of power available to the infrared heater, a temperature of the passenger compartment, and an occupancy level of the passenger compartment.

8. A method for a vehicle, comprising: conditioning a passenger compartment of a vehicle by radiating heat using infrared heaters and by heating an air flow using a heating device; varying the output of the heating device based on the amount of power available to the infrared heater; controlling the heating device based on the target value; as well as The target value is selectively reduced when sufficient power is available for the infrared heater.

9. The method according to claim 8, wherein The heating device includes a heater core supplied by a coolant, and wherein the target value is a temperature of the coolant at an inlet of the heater core.

10. The method according to claim 8, wherein The heating device includes an air heater, and wherein the target value is the amount of power consumed by the air heater.

11. The method according to claim 8, wherein The heating device includes an air heater, and wherein the target value is an exhaust air temperature.

12. The method according to claim 8, wherein The heating device is a coolant heater, and wherein the target value is a coolant temperature.

Images