Hybrid vehicles

Abstract

The present invention relates to a hybrid vehicle, which comprises: an internal combustion engine; an electric motor; an interior air conditioning device; a catalytic converter assigned to the internal combustion engine, the catalytic converter having a catalytic converter heating device that can be operated at a first voltage from a medium-voltage power grid, in particular a voltage of 48V; a high-voltage power grid at a second voltage higher than the first voltage, to which the electric motor is connected; a voltage converter for converting the second voltage into the first voltage; a heat exchange device for heating a temperature control medium of the interior air conditioning device circulating in a temperature control circuit using waste heat from the internal combustion engine; and a control device for operating the catalytic converter heating device in accordance with the operation of the internal combustion engine, wherein an air conditioning and heating device of the interior air conditioning device that operates at the first voltage is connected to the medium-voltage power grid, wherein the control device is designed to operate the air conditioning and heating device from the medium-voltage power grid at least when the internal combustion engine is not operating and / or the catalytic converter heating device is not operating.

Description

Technical Field

[0001] The present invention relates to a hybrid vehicle, which comprises: an internal combustion engine; an electric motor; an interior air conditioning device; a catalytic converter assigned to the internal combustion engine, the catalytic converter having a catalytic converter heating device operable at a first voltage, in particular 48 V, from a medium-voltage power grid; a high-voltage power grid at a second voltage higher than the first voltage, the electric motor being connected to the high-voltage power grid; a voltage converter for converting the second voltage into the first voltage; a heat exchange device for heating a temperature control medium circulating in a temperature control circuit of the interior air conditioning device using waste heat from the internal combustion engine; and a control device for operating the catalytic converter heating device in accordance with the operation of the internal combustion engine. Background Art

[0002] A hybrid vehicle is characterized in that it has both a particularly conventional internal combustion engine and an electric motor in the drive train that can be operated in generator mode and can also be used for driving. The electric motor is usually connected to the high-voltage power grid of the hybrid vehicle, the high voltage of which can in particular be greater than 200 V, for example 450 V. A high-voltage battery is usually also provided in the high-voltage power grid, from which the electric motor can be fed. In so-called plug-in hybrid vehicles, the hybrid vehicle also includes a charging device that allows the high-voltage battery to be charged, for example, via a corresponding charging post, a wall box and / or a common household connection.

[0003] In modern motor vehicles, an internal combustion engine is usually associated with a catalytic converter for treating exhaust gas. Such a catalytic converter begins to work effectively when a certain operating temperature is reached. In order to allow effective use of the catalytic converter even at low temperatures, for example directly after starting the internal combustion engine, it has been proposed to equip the catalytic converter with a catalytic converter heating device, which can be designed as a heating disk, for example. Such a heating disk is formed by a wound metal bracket, which can be powered if necessary and is installed in the housing of the catalytic converter.

[0004] The desired heating power of such a catalyst heater can be, for example, in the range of several kilowatts, for example, 4 kW. However, conventional motor vehicle onboard power grids usually only provide a low voltage of 12V, which requires an extremely high current supply in order to be able to operate the catalyst heater accordingly, which results in a corresponding design that is both expensive and cumbersome. Therefore, at least for hybrid vehicles, it has been proposed to operate the catalyst heater at a medium voltage (medium voltage), in particular at 48V. For example, the medium voltage can be provided by the high voltage grid of the motor through a corresponding voltage converter, and a lower current intensity can be used, thereby greatly reducing the requirements for the catalyst heater and its input pipeline. For example, such a design can be found in the document DE 198 04 098 A1. According to the document DE 10 2012 209 202 A1, an alternative is proposed, namely, using a regenerative braking system to provide energy for heating the motor vehicle catalyst.

[0005] Hybrid vehicles also usually have an interior air conditioning system, which is specially designed to heat the interior to a comfortable temperature, in particular a temperature that can be selected by the passengers. For this purpose, it is known in conventional motor vehicles that only have an internal combustion engine to transfer the waste heat of the internal combustion engine to a temperature control circuit, for example using cooling water, or, if necessary, directly to the air to be supplied to the interior, in order to provide the desired heating. However, in hybrid vehicles, at least no waste heat is generated for heating the interior when the hybrid vehicle is driven purely electrically. Accordingly, it is proposed to operate a temperature control medium, in particular cooling water, in the temperature control circuit by means of a high-voltage resistance heater, in particular a high-voltage PTC, which is operated by the high-voltage power grid. When the internal combustion engine generates corresponding waste heat, this high-voltage heating device does not have to be operated all the time, and this waste heat is also discharged through the water of the temperature control circuit, which is also used to cool the internal combustion engine.

[0006] In addition to this possibility for heating the temperature-control medium, the heat of which is in turn used to heat the air to be supplied to the interior space, in particular with the aid of a heat exchanger, the interior air-conditioning systems of known hybrid vehicles usually also have a low-voltage heating device for the air to be supplied to the interior space, which is operated in the 12V onboard power supply system and is operated by the low-voltage onboard power supply system and is unable to provide sufficient power itself to provide the required sufficient heat, but can be used for initial heating of the air in the case of a cold internal combustion engine and / or can be used for subsequent regulation / supplementary heating actions at a later point in time.

[0007] The known designs of hybrid vehicles have the problem that, due to the high-voltage components involved, the high-voltage heating device requires complex and space-consuming additional components in terms of design and safety requirements, which in current hybrid vehicles cannot always be integrated into the vehicle structure or can only be integrated into the vehicle structure if damaged. Summary of the invention

[0008] It is therefore an object of the present invention to specify a relatively improved hybrid vehicle, in particular with regard to the required components and space requirements.

[0009] To achieve this object, it is proposed according to the invention in a hybrid vehicle of the type mentioned at the outset that an air-conditioning and heating device of an interior air-conditioning system operated at a first voltage is connected to a medium-voltage network, wherein the control device is designed to operate the air-conditioning device from the medium-voltage network when the internal combustion engine and / or the catalytic converter heating device are not operating.

[0010] The invention makes use of the fact that, in particular in connection with the development of a replacement of a conventional 12V onboard electrical system with a 48V onboard electrical system, an air conditioning and heating system for air to be introduced into the interior of a motor vehicle has been developed, which can therefore be operated with an operating voltage of 48V, which preferably corresponds to a first voltage (medium voltage). According to the invention, it has now been recognized that if a first voltage between a second voltage (high voltage) of the high-voltage electrical system and a third voltage (low voltage) of the low-voltage electrical system (onboard electrical system) is already available, which is used to operate a catalytic converter heater, then this catalytic converter heater can also be used to operate such an air conditioning and heating system at the first voltage instead of a 12V heater. This is particularly evident from the further recognition that, when the catalytic converter heater is in operation, the air conditioning and heating system is not required precisely because the internal combustion engine then provides waste heat. On the other hand, when an electric machine that does not provide waste heat is used, the catalytic converter heater is usually not required or a low power of the catalytic converter heater is required, so that the air conditioning and heating system of the interior air conditioning system is required to provide the desired interior heating. In other words, when the electric machine is operated via the voltage converter, the first voltage present in the medium voltage network is provided even if the catalytic converter heating device is not currently required (or is required only to a small extent), so that the voltage converter for providing the first voltage from the second voltage can ultimately be used for other purposes.

[0011] In the hybrid vehicle according to the invention, the hybrid vehicle also has an onboard power supply system at a third voltage lower than the first voltage or the second voltage, the third voltage being in particular 12 V, i.e. making full use of the availability of a medium voltage, i.e. a first voltage between the second voltage and the third voltage, for providing an alternative device for providing sufficient heating power at a sufficiently low current intensity for heating the air supplied to the interior of the motor vehicle, which alternative device replaces the conventional 12 V heating device of the interior air conditioning system and the high-voltage heating device for the temperature control medium, so that by providing an air conditioning heating device that can be operated at the first voltage, a high-voltage heating device that can be operated at the second voltage of the high-voltage power supply system, i.e. in particular a high-voltage PTC heater, can be omitted. This in turn means that costs and weight can be significantly reduced and more free installation space is available in the hybrid vehicle for other components or as space that can be used by passengers.

[0012] Since the application of the present invention in plug-in hybrid electric vehicles (PHEV) is particularly advantageous, the present invention can of course also be used in other hybrid vehicles, for example mild hybrid vehicles using a 12V onboard electrical system.

[0013] There are basically two operating scenarios within the scope of the present invention. In the first operating state, the internal combustion engine is turned off or cold, and the hybrid vehicle is driven electrically using the electric machine. Since the hybrid vehicle is then driven purely electrically, the internal combustion engine does not generate any waste heat to heat the interior of the hybrid vehicle. It is also not necessary to heat the catalytic converter, since the internal combustion engine does not generate exhaust gas that must be cleaned. The full power can then be used by the voltage converter for the air conditioning and heating system to achieve heating of the interior.

[0014] In the second operating state, the internal combustion engine is started or heated up, so that waste heat is generated by combustion, which is dissipated via a temperature control circuit, in particular cooling water, and, for example, via a heat exchanger of an interior air conditioning system, to heat the interior of the motor vehicle. The voltage converter therefore does not have to be used to heat the interior, so that during operation the voltage converter is used to heat the catalytic converter via the catalytic converter heating device and to heat the catalytic converter as quickly as possible so that the catalytic converter can function quickly.

[0015] In this case, the control device naturally controls the interior air conditioning system as a function of specifications made, in particular by the user, for example a selected desired interior temperature.

[0016] As already indicated, the air conditioning and heating device is particularly advantageously an air conditioning and heating device designed to heat the air to be introduced into the interior to be heated. Thus, the air to be introduced into the interior to be heated can be heated by means of a temperature control circuit, in particular by cooling water of the internal combustion engine, and by the air conditioning and heating device operated at a first voltage. In particular, the interior air conditioning device can also have a further heat exchange device for transferring heat from a temperature control medium heated by the waste heat of the engine to the air to heat the interior.

[0017] The air conditioning device can particularly advantageously be or include a resistance heater, in particular a PTC heater (PTC-“Positive Temperature Coefficient”). As already mentioned, such air conditioning and heating devices have been developed for motor vehicles which use a 48V onboard power supply instead of a 12V onboard power supply, so that the corresponding components can be used as identical components in hybrid vehicles according to the invention and in vehicles which operate essentially with a 48V onboard power supply.

[0018] As already mentioned, the control device can be designed to operate exclusively the catalytic converter heating device or exclusively the air conditioning heating device in at least two first operating modes. This means in particular that the air conditioning heating device can be operated when the internal combustion engine is turned off (and in particular cold) and the electric machine is used, while the catalytic converter heating device can be used only during the operation of the internal combustion engine and the waste heat is provided. However, within the scope of the present invention, it is also conceivable that the control device is designed to operate the catalytic converter heating device and the air conditioning heating device simultaneously from the medium voltage network in at least one operating mode. This means that a mixed form of the operating states already discussed above is conceivable, in which, for example, the catalytic converter is kept hot, while the interior is to be heated by means of the air conditioning heating device at the same time. The voltage converter can be designed accordingly in terms of the output power of the voltage converter, for example, in order to operate two heating devices, if necessary, with a reduced but sufficient heating power. Specifically, it can be provided, for example, that the control device is designed to operate the catalytic converter heating device with a reduced heating power in the second operating mode to maintain the minimum temperature of the already heated catalytic converter. In this case, the corresponding second operating mode can be a warming mode, which can generally lead to energy saving.

[0019] In order to be able to use the catalytic converter heater and the air conditioning heater accordingly, the control device may have at least one switching device for switching the power supply to the catalytic converter heater and the power supply to the air conditioning heater. For example, the at least one switching device may be connected downstream of the voltage converter accordingly. If the switching device is not considered to be part of the control device, the switching device may also be implemented outside the control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages and details of the invention are apparent from the following description of the exemplary embodiments and from the accompanying drawings. Here, the following are shown:

[0021] Figure 1 A hybrid vehicle according to the invention is shown in a first operating state, and

[0022] Figure 2 The hybrid vehicle according to the invention is shown in a second operating state. DETAILED DESCRIPTION

[0023] Figure 1 The schematic diagram of a hybrid vehicle 1 according to the invention is shown. The hybrid vehicle has both an electric machine 2 and an internal combustion engine 3 in the powertrain. The electric machine 2 is connected to a high-voltage grid 4 at a second voltage (high voltage). In addition, a high-voltage battery 5 is also connected to the high-voltage grid 4, which can be charged by a charging device not shown in detail, so that the hybrid vehicle 1 is a plug-in hybrid vehicle.

[0024] The internal combustion engine 3 is provided with a catalytic converter 6, which has a catalytic converter heating device 7, which is designed as a heating disk. The catalytic converter heating device 7 can be operated at a first voltage (medium voltage), which is obtained from the second voltage of the high-voltage power grid 4 by means of a voltage converter 8, so that the voltage converter 8 provides the medium-voltage power grid 9 with a first voltage. The hybrid vehicle 1 also has an onboard power grid (low-voltage power grid) which is not shown in detail for the sake of clarity, and the third voltage of the onboard power grid is lower than the first voltage and the second voltage. In the example, the first voltage can be 48V, the second voltage can be 450V, and the third voltage can be 12V.

[0025] Furthermore, the internal combustion engine 3 is coupled to a temperature control circuit 11 via a heat exchange device 10, so that the waste heat of the internal combustion engine 3 during its operation can be used to heat a temperature control medium, here cooling water. With the aid of a further heat exchange device 13, this heat can be used in an interior air conditioning device 12 to heat the air to be supplied to the interior of the motor vehicle 1. The interior air conditioning device 12 accordingly comprises an air source 14 for external air and / or circulated interior air and a distribution device 15 for distributing the heated air in the interior of the hybrid vehicle 1 to achieve heating of the interior.

[0026] However, the interior air conditioning device 12 also comprises an electrical air conditioning heater 16 which can also be used to heat the air to be supplied to the interior. The air conditioning heater 16 is designed as a PTC heater and is also operated at a first voltage, here 48 V, generated by the voltage converter 8. By means of the only schematically shown switching devices 17, 18 of the control device 19 which can also include a controller 20, the voltage converter 8 can supply both the catalytic converter heater 7 and the air conditioning heater 16 with current and thus with corresponding electrical power.

[0027] exist Figure 1 and Figure 2 In both operating states shown, the interior is now to be heated, which can be selected, for example, by the occupants of the hybrid vehicle 1 via corresponding operating devices. Figure 1 In the first operating state, the internal combustion engine 3 is not used and is cold. The electric machine 2 is used for driving. Accordingly, no heat is output to the temperature control circuit 11, so that the other heat exchange device 13 cannot be used to heat the air of the air source 14 to be supplied to the interior of the motor vehicle 1. On the other hand, no exhaust gas is produced either, so that the catalytic converter 6 does not need to be heated, and therefore the catalytic converter heating device 7 does not need to be operated. As shown according to the switching devices 17 and 18, the control device 19 is designed to exclusively supply power to the air conditioning heating device 16 in this operating state, so that despite the absence of waste heat from the internal combustion engine 3, the air can still be heated by the air conditioning heating device 16 according to the arrow 21 (see arrow 22) and can be output to the interior of the motor vehicle 1 through the air distribution device 15 (see arrow 23). For this purpose, a high-pressure heating device for the cooling water of the temperature control circuit 11 is not required as in conventional hybrid vehicles.

[0028] Figure 2 A second operating state is shown, in which the internal combustion engine 3 is running and waste heat is therefore introduced into the temperature control circuit 11 according to arrow 24. In this case, see arrows 25 and 26, the air to be introduced into the interior can be heated by means of the further heat exchange device 13, while the air conditioning heating device 16 is not running, see the position of the switch device 17. Instead, see the position of the switch device 18, electrical power is supplied to the catalytic converter heating device 7 by the voltage converter 8 via the control device 19 in order to heat the catalytic converter 6.

[0029] Apart from Figure 1 and Figure 2In addition to the operating modes shown, in which either only the air conditioning heater 16 or only the catalytic converter heater 7 is operated, mixed states are also conceivable, for example, operating the catalytic converter heater 7 at reduced power to maintain a certain minimum temperature while heating the air for the interior via the air conditioning heater 16. Of course, other second operating modes of this type can also be implemented accordingly by the control device 19.

Claims

1. A hybrid vehicle (1), comprising: an internal combustion engine (3); an electric motor (2); an interior air conditioning system (12); a catalytic converter (6) assigned to the internal combustion engine (3), the catalytic converter having a catalytic converter heating device (7) operable at a first voltage from a medium voltage network (9); a high voltage network at a second voltage higher than the first voltage, the electric motor (2) being connected to the high voltage network; a voltage converter (8) for converting the second voltage into a first voltage; a heat exchange device (10) for heating a temperature control medium of the interior air conditioning system (12) circulating in a temperature control circuit (11) using waste heat from the internal combustion engine (3); and a control device (19) for operating the catalytic converter heating device (7) in accordance with the operation of the internal combustion engine (3), It is characterized in that An air conditioning and heating device (16) of the interior air conditioning device (12) operating at the first voltage is connected to the medium-voltage power grid (9), and the control device (19) is designed to operate the air conditioning and heating device (16) from the medium-voltage power grid (9) at least when the internal combustion engine (3) is not operating and / or the catalytic converter heating device (7) is not operating.

2. The hybrid vehicle (1) according to claim 1, characterized in that The hybrid vehicle (1) further comprises an onboard electrical system at a third voltage, which is lower than the first voltage and the second voltage.

3. The hybrid vehicle (1) according to claim 1 or 2, characterized in that: The air conditioning and heating device (16) is designed to heat air to be introduced into an interior space to be heated.

4. The hybrid vehicle (1) according to claim 3, characterized in that: The interior air conditioning device (12) also has a further heat exchange device (13) for transferring heat from a temperature control medium heated by waste heat from the internal combustion engine (3) to air for heating the interior.

5. The hybrid vehicle (1) according to claim 1 or 2, characterized in that: The air conditioning heating device (16) is a resistance heater or includes a resistance heater.

6. The hybrid vehicle (1) according to claim 1 or 2, characterized in that: The control device (19) is designed to operate the catalytic converter heating device (7) exclusively or the air conditioning heating device (16) exclusively from the medium-voltage power grid (9) in at least two first operating modes, and / or to operate the catalytic converter heating device (7) and the air conditioning heating device (16) simultaneously from the medium-voltage power grid (9) in at least one second operating mode.

7. The hybrid vehicle (1) according to claim 6, characterized in that The control device (19) is designed to operate the catalytic converter heating device (7) at a reduced heating power in the second operating mode in order to maintain a minimum temperature of the heated catalytic converter (6).

8. The hybrid vehicle (1) according to claim 1 or 2, characterized in that: The control device (19) has at least one switching device (17, 18) for switching the power supply to the catalytic converter heating device (7) and the power supply to the air conditioning heating device (16).

9. The hybrid vehicle (1) according to claim 1 or 2, characterized in that: The hybrid vehicle is designed as a plug-in hybrid vehicle (1).

10. The hybrid vehicle (1) according to claim 1, characterized in that The first voltage is 48V.

11. The hybrid vehicle (1) according to claim 2, characterized in that The third voltage is 12V.

12. The hybrid vehicle (1) according to claim 5, characterized in that The resistance heater is a PTC heater.

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