Motor vehicle with a solar cell arrangement, method for operating such a motor vehicle, and computer program product

Abstract

The invention relates to a motor vehicle (1) with an electric drive unit (2), a traction battery (4) electrically connected to the drive unit (2) via a switch assembly (5), and a solar cell assembly (8) for providing electrical energy. The solar cell assembly (8) is electrically connected to the traction battery (4) via the switch assembly (5), with the drive unit (2) being electrically connected to the traction battery (4) in a first switching state of the switch assembly (5), and the solar cell assembly (8) being electrically connected to the traction battery (4) in a second switching state of the switch assembly (5). The invention further relates to a method for operating a motor vehicle (1) and a computer program product.

Description

[0001] The invention relates to a motor vehicle with an electric drive unit, a traction battery electrically connected to the drive unit via a switch arrangement, and a solar cell arrangement for providing electrical energy. The invention further relates to a method for operating a motor vehicle and a computer program product.

[0002] For example, the prior art is known from German patent application DE 10 2021 119 729 A1. This describes a charging device in an electric vehicle that enables the use of electricity from a photovoltaic system to charge a high-voltage battery in the electric vehicle. The charging device is connected to the high-voltage battery via a dedicated input. Furthermore, a battery management system is designed to switch the photovoltaic feed-in to the high-voltage battery on and off via at least one additional switch.

[0003] Furthermore, US Patent 11,325,495 B2 describes a solar charge controller comprising: a processor configured to receive electricity generated by a solar panel; to determine when a charging operating condition is met, based on state information relating to the solar panel; and to determine when to activate a charging mode, based on a vehicle's starting state and state information relating to a vehicle battery. The solar charge controller further comprises an inverter connected to the solar panel that converts the solar panel's output into charging energy and delivers the charging energy to the battery in response to a command from the processor, the vehicle's battery comprising a first battery and a second battery.

[0004] The processor is configured to perform the following steps: comparing the state of charge of the first battery and the state of charge of the second battery by a battery management system when it is determined that a vehicle start is enabled; selecting the first battery or the second battery as a charging target based on the result of comparing the state of charge of the first battery and the state of charge of the second battery; and activating the charging mode to charge the selected battery, that is, the first battery or the second battery.

[0005] Further state of the art can be found in publications such as WO 2020 / 229475 A1, WO 2022 / 224210 A1 and WO 2023 / 077035 A1.

[0006] The object of the invention is to propose a motor vehicle which has advantages over known motor vehicles, in particular enabling the efficient use of solar energy for the operation of the motor vehicle.

[0007] This is achieved according to the invention with a motor vehicle having the features of claim 1. It is provided that the solar cell arrangement is electrically connected to the traction battery via the switch arrangement, wherein in a first switching state of the switch arrangement the drive unit and in a second switching state of the switch arrangement the solar cell arrangement is electrically connected to the traction battery.

[0008] Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims. It should be noted that the exemplary embodiments described in the description are not limiting; rather, any variations of the features disclosed in the description, the claims, and the figures are possible.

[0009] The motor vehicle has at least the electric drive system, the switch assembly, the traction battery, and the solar cell assembly. The drive system serves to propel the motor vehicle and thus to provide the drive torque directed towards propelling the motor vehicle. To provide the drive torque, the drive system has at least one drive unit, which is designed as an electric traction motor.

[0010] The electric traction motor is electrically connected to the traction battery. The traction battery serves as an intermediate storage medium for electrical energy to operate the drive system. The drive system, or drive unit, is thus operated, at least temporarily, with electrical energy drawn from the traction battery. However, it is also possible to feed electrical energy generated by the electric drive system into the traction battery. The connection between the drive system and the traction battery is established via a switch assembly. A switch assembly is defined as an arrangement with any number of switches by which an electrical connection between the traction battery and the drive system can be selectively established or broken.

[0011] The switch arrangement therefore includes at least one switch, for example a single switch, but preferably several switches. The switch is preferably in the form of a contactor. A contactor is understood to be an electrical switch that can be electrically controlled. For example, the contactor is normally open. This means that it only establishes an electrical connection when it is energized. If it is not energized, the electrical connection between the drive unit and the traction battery is interrupted.

[0012] In the first switching state of the switch arrangement, the traction battery is electrically connected to the drive unit, whereas in the second switching state, it is electrically disconnected from the drive unit. In the case of multiple switches, these are arranged, for example, between different electrical terminals of the traction battery and the drive unit; a first switch is thus located between a first electrical terminal of the traction battery and a first electrical terminal of the drive unit, and a second switch is located between a second electrical terminal of the traction battery and a second electrical terminal of the drive unit. The switches preferably serve to switch different electrical potentials, in particular different electrical poles.For example, the first terminal of the traction battery is a positive terminal and the second terminal of the traction battery is a negative terminal.

[0013] The vehicle also features a solar cell array for generating electrical energy. This array is preferably mounted externally on the vehicle. It converts solar energy into electrical energy, thereby increasing the vehicle's range. The term "solar cell array" refers to any number of solar cells. It can include one or more individual solar cells. In other words, the solar cell array comprises at least one solar cell.

[0014] The space available for the solar cell array on the vehicle is limited, which also limits the area of ​​the solar cell array. This means that the solar cell array can only provide a relatively small amount of electrical energy to power the vehicle. Under optimal conditions, the electrical energy provided by the solar cell array can increase the vehicle's range by several hundred or a few thousand kilometers.

[0015] Under realistic assumptions, the additional range amounts to a few hundred kilometers per year, meaning that at most a few dozen kilometers of additional range can be achieved per month. Such a small additional range is hardly noticeable to a vehicle user. For example, the solar panel array is only electrically connected to the drive system when the traction battery is also electrically connected to the drive system. If the solar panel array is to be connected to the traction battery even when the drive system is not connected to it, particularly to charge the battery with the supplied electrical energy, an additional switch arrangement is necessary. The comparatively high cost outweighs the minimal additional benefit.

[0016] For this reason, the invention proposes to electrically connect the solar cell arrangement to the traction battery via the same switch arrangement as the drive unit. The switch arrangement consequently has several connections, namely a first switching connection for the traction battery, a second switching connection for the solar cell arrangement, and a third switching connection for the drive unit. The switch arrangement is adjustable to one of several switching states, namely at least to the first switching state and the second switching state.

[0017] The switch arrangement is designed such that in the first switching state, the drive unit and in the second switching state, the solar cell arrangement are electrically connected to the traction battery. Preferably, the switching states adjustable on the switch arrangement comprise only the first and second switching states. Accordingly, the traction battery can be selectively connected either to the drive unit or to the solar cell arrangement. This allows for a comparatively simple electrical connection of the solar cell arrangement to the traction battery.

[0018] For example, it is intended that the drive unit is electrically connected to the traction battery only while the vehicle is in motion, via the switch arrangement. When the vehicle is not in motion, i.e., when it is stationary or parked, the drive unit is electrically disconnected from the traction battery by adjusting the switch arrangement accordingly. The described vehicle design thus provides that the solar cell arrangement is electrically connected to the traction battery specifically, for example, always and / or only when the battery is electrically disconnected from the drive unit.

[0019] This means that the traction battery is charged with the electrical energy provided by the solar cell array, and specifically only charged while the drive system is electrically disconnected from the traction battery, particularly when the vehicle is stationary or parked. Since the vehicle typically has idle periods that are longer than its driving times, a larger proportion of the supplied electrical energy can be used for driving the vehicle in this way, namely indirectly by charging the traction battery.

[0020] A further development of the invention provides that the switch arrangement is configured such that, in the first switching state, the traction battery is electrically connected to the drive unit and electrically disconnected from the solar cell arrangement, and / or that, in the second switching state, the traction battery is electrically disconnected from the drive unit and electrically connected to the solar cell arrangement. In other words, the traction battery is connected by means of the switch arrangement either to the drive unit or to the solar cell arrangement, but not to both simultaneously.

[0021] Accordingly, the switch arrangement is preferably designed and configured exclusively for setting the first and second switching states, but not for setting a further switching state in which, for example, the drive unit and the traction battery are simultaneously electrically connected to the solar cell arrangement. The described design of the motor vehicle achieves the advantages already mentioned.

[0022] A further development of the invention provides that the switch arrangement is electrically controlled and is in the first switching state when energized with a switching current and in the second switching state when de-energized. This means that the switch arrangement must be continuously energized with the switching current to establish and maintain the first switching state. As soon as the switching current is removed, i.e., the switch arrangement is no longer energized, the switch arrangement switches from the first switching state to the second switching state. It remains in the second switching state until it is again energized with the switching current. Preferably, the at least one switch of the switch arrangement is configured as a contactor. The switching current is preferably applied to the switch arrangement only while the vehicle is in motion, but not when the vehicle is stationary or parked.This also serves to achieve the aforementioned advantages.

[0023] A further development of the invention provides that the switch arrangement includes an electrically controlled magnetic coil for the magnetic displacement of a busbar, wherein the busbar is electrically connected to the traction battery on one side and, in the first switching state, to the drive unit and, in the second switching state, to the solar cell arrangement on the other. The magnetic coil is designed and configured to be supplied with the aforementioned switching current. The magnetic coil serves to displace the busbar, by means of which the traction battery is electrically connected either to the drive unit or the solar cell arrangement, or electrically connected to the respective unit.

[0024] In the first switching state, the busbar is in a first position, and in the second switching state, it is in a second position. It is subjected to a spring force by means of a spring element, which pushes it towards the second position. Thus, when the magnetic coil is energized with the switching current, the busbar is moved into the first position against the spring force exerted by the spring element and remains there only as long as the magnetic coil is also energized with the switching current. When the switching current is removed, i.e., when the magnetic coil is no longer energized, the spring force pushes the busbar from the first position towards the second position, specifically into the second position. This ensures both a high level of vehicle safety and a reliable integration of the solar cell array using simple means.

[0025] A further development of the invention provides that the switch arrangement has a first switch which has a first switching terminal electrically connected to the traction battery, a second switching terminal electrically connected to the solar cell arrangement and a third switching terminal electrically connected to the drive system, wherein the first switch is in a first switching position in the first switching state and in a second switching position in the second switching state, wherein the third switching terminal is electrically connected to the first switching terminal and electrically disconnected from the second switching terminal in the first switching position and is electrically disconnected from the first switching terminal and electrically connected to the second switching terminal in the second switching position.

[0026] The first switch is therefore electrically connected to the traction battery, the drive unit, and the solar cell array. Preferably, the first switch is permanently electrically connected to both the traction battery and the solar cell array.

[0027] Preferably, it is electrically connected to the drive unit via a second switch and is therefore only temporarily electrically connected to the drive unit.

[0028] The first switch has three switching terminals: the first switching terminal, the second switching terminal, and the third switching terminal. The first switching terminal is electrically connected to the traction battery, preferably permanently. The second switching terminal is electrically connected to the solar cell array, preferably permanently. The third switching terminal is electrically connected to the drive unit, for example, permanently or via the aforementioned second switch.

[0029] In the first switching state of the switch arrangement, the first switch is in the first switching position, and in the second switching state, it is in the second switching position. In the first switching state, the third switching terminal is electrically connected to the first switching terminal and electrically disconnected from the second switching terminal. In the second switching state, the third switching terminal is electrically disconnected from the first switching terminal and electrically connected to the second switching terminal. This achieves the aforementioned advantages, and the solar cell arrangement can be electrically integrated into the vehicle with minimal circuitry complexity.

[0030] A further development of the invention provides that the switch arrangement has a second switch which has a first switching terminal electrically connected to the third switching terminal of the first switch and a second switching terminal electrically connected to the drive unit, or which has a first switching terminal electrically connected to the traction battery, a second switching terminal electrically connected to the solar cell arrangement and a third switching terminal electrically connected to the drive unit, wherein the second switch is in a first switching position in the first switching state and in a second switching position in the second switching state.wherein the third switching terminal is electrically connected to the first switching terminal and electrically disconnected from the second switching terminal in the first switching position, and electrically disconnected from the first switching terminal and electrically connected to the second switching terminal in the second switching position.

[0031] Basically, two different versions of the second switch can be distinguished. In the first version, the second switch has a first switching terminal and a second switching terminal. The first switching terminal of the second switch is electrically connected to the third switching terminal of the first switch, preferably permanently. The second switching terminal of the second switch is electrically connected to the drive unit, preferably permanently. Therefore, the drive unit can be electrically connected to the first switch, or rather to the third switching terminal of the first switch, using the second switch.

[0032] In a second variant, the second switch is designed analogously to the first, meaning it also has a first, second, and third switching terminal. These are connected analogously to the first switch: the first terminal to the traction battery, the second to the solar panel array, and the third to the drive unit. For example, different electrical potentials can be switched using the first and second switches, specifically a positive terminal using the first switch and a negative terminal using the second switch, or vice versa. In each case, the aforementioned advantages are achieved.

[0033] A further development of the invention provides that an electrical intermediate storage device is electrically connected to the solar cell arrangement, in particular via a switch, wherein the electrical intermediate storage device is electrically connected to the solar cell arrangement in the first switching state of the switch arrangement and electrically disconnected from the solar cell arrangement in the second switching state of the switch arrangement. The intermediate storage device is preferably an intermediate storage device that can absorb and / or release electrical energy with a higher nominal power than the traction battery. For example, the intermediate storage device is designed as a capacitor, preferably as a supercapacitor or supercap. This means that the intermediate storage device has a lower energy density than the traction battery, but a higher power density.

[0034] Preferably, the intermediate storage device is electrically connected to the solar cell array whenever the switch assembly is in its first switching state. Conversely, the intermediate storage device is electrically disconnected from the solar cell array when the switch assembly is in its second switching state. In other words, the electrical energy provided by the solar cell array is temporarily stored using the intermediate storage device until it is used by the traction battery.

[0035] Preferably, the intermediate storage device is electrically connected to the solar cell array via the switch. The switch is closed, for example, whenever the switch array is in its first switching state, and opened when it is in its second switching state. In other words, the intermediate storage device serves to temporarily store the electrical energy provided by the solar cell array while the vehicle is in operation, but not while the vehicle is stationary or parked. This measure also utilizes the electrical energy provided during operation.

[0036] A further development of the invention provides that the electrical energy storage device can be electrically connected to the drive unit when the first switching state of the switch arrangement is present. This means that the electrical energy temporarily stored in the storage device is used to operate the drive unit, at least temporarily. The storage device serves as support for the traction battery; preferably, it enables at least short-term operation of the drive unit with higher power than when using the traction battery alone. The storage device thus enables a so-called boost mode for the vehicle. This allows the electrical energy provided by the solar cell arrangement to be used in a clearly perceptible way for the vehicle's user.

[0037] The invention further relates to a method for operating a motor vehicle, in particular a motor vehicle as described in this description, wherein the motor vehicle has an electric drive unit, a traction battery electrically connected to the drive unit via a switch arrangement, and a solar cell arrangement for providing electrical energy. It is provided that the solar cell arrangement is electrically connected to the traction battery via the switch arrangement, wherein in a first switching state of the switch arrangement the drive unit and in a second switching state of the switch arrangement the solar cell arrangement is electrically connected to the traction battery.

[0038] The advantages of such a vehicle design or such a procedure have already been mentioned. Both the vehicle and the method for operating it may be further developed as explained in this description, and reference is made to these explanations in that regard.

[0039] Furthermore, the invention relates to a computer program product comprising commands that cause the motor vehicle to execute the described method in accordance with the details of this description. For the advantages and possible advantageous developments, reference is made to the description in its entirety.

[0040] The features and combinations of features described in the description, in particular those described in the following figure description and / or shown in the figures, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. Thus, embodiments that are not explicitly shown or explained in the description and / or the figures, but which emerge from or can be derived from the explained embodiments, are also to be considered as encompassed by the invention.

[0041] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without limiting the invention. The only embodiment shown is... Fig. 1 A schematic representation of a motor vehicle with an electric drive system, a traction battery and a solar cell arrangement.

[0042] The Fig.Figure 1 shows a highly schematic representation of a motor vehicle 1, which has a drive unit 2, of which an inverter 3, in particular a pulse inverter, is shown here purely by way of example. The drive unit 2 is electrically connected to a traction battery 4 of the motor vehicle 1, namely via a switch assembly 5. The switch assembly 5 has at least a first switch 6 and a second switch 7. Furthermore, the motor vehicle 1 has a solar cell assembly 8 and an (optional) intermediate storage device 9. The intermediate storage device 9 is electrically connected to the switch assembly 5 via a further switch assembly 10. The switch assembly 10 includes, purely by way of example, a first switch 11 and a second switch 12.

[0043] The first switch 6 of the switch arrangement 5 has a first switching terminal 13, a second switching terminal 14, and a third switching terminal 15. The first switching terminal 13 is electrically connected to the traction battery 4, the second switching terminal 14 to the solar cell arrangement 8, and the third switching terminal 15 to the drive unit 2. Preferably, the first switching terminal 13 is permanently electrically connected to the traction battery 4 and the second switching terminal 14 is permanently electrically connected to the solar cell arrangement 8. The third switching terminal 15, however, is connected to the drive unit 2 via the second switch 7, so that it is only electrically connected to the drive unit 2 when the second switch 7 is closed and is otherwise disconnected from it. It should be noted that the second switch 7 can be omitted in the configuration shown here; it is therefore optional.

[0044] The switch arrangement 10, by means of which the intermediate storage device 9 is electrically connected to the switch arrangement 5, enables an electrical connection of the intermediate storage device 9 to the solar cell arrangement 8 and to the drive unit 2. In particular, it is directly electrically connected to the solar cell arrangement 8 when the first switch 11 is closed, even when the first switch 6 is in a switching state in which the solar cell arrangement 8 is disconnected from the traction battery 4. The second switch 12 of the switch arrangement 10 also enables the intermediate storage device 9 to be electrically connected to the drive unit 2, especially when the second switch 7 is closed.

[0045] By means of the switch arrangement 10, the intermediate storage device 9 can be charged with electrical energy provided by the solar cell arrangement 8, while the solar cell arrangement 8 is otherwise electrically isolated from the traction battery 4 and the drive unit 2. The electrical energy temporarily stored in the intermediate storage device 9 can then be used to operate the drive unit 2, preferably in addition to the electrical energy drawn from the traction battery 4. The electrical energy drawn from the intermediate storage device 9 serves to perform a boost operation of the drive unit.

[0046] Preferably, the motor vehicle 1 has a display device (not shown here). This display device shows the user of the motor vehicle 1 the amount of energy stored in the intermediate storage unit 9. Based on this information, the user can decide whether to use the corresponding energy to operate the drive unit 2, in particular to perform the aforementioned boost operation. The electrical energy provided by the solar cell arrangement 8 is therefore not only used for a comparatively small increase in range, but is also intended to be temporarily stored when the motor vehicle 1 is parked, and is used during the operation of the motor vehicle 1 for a short-term increase in power. REFERENCE MARK LIST: 1 motor vehicle 2 Drive unit 3 inverters 4 traction batteries 5 Switch arrangement 6 1. Switch 7 2. Switch 8 Solar cell arrangement 9 buffers 10 Switch arrangement 11 1. Switch 12 2. Switch 13 1. Switching connection 14 2. Switching connection 15 3. Switching connection QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 119 729 A1

[0002] US 11,325,495 B2

[0003] WO 2020 / 229475 A1

[0005] WO 2022 / 224210 A1

[0005] WO 2023 / 077035 A1

[0005]

Claims

[1] Motor vehicle (1) with an electric drive unit (2), with a traction battery (4) electrically connected to the drive unit (2) via a switch arrangement (5) and with a solar cell arrangement (8) for providing electrical energy, characterized by , that the solar cell arrangement (8) is electrically connected to the traction battery (4) via the switch arrangement (5), wherein in a first switching state of the switch arrangement (5) the drive unit (2) and in a second switching state of the switch arrangement (5) the solar cell arrangement (8) is electrically connected to the traction battery (4). [2] Motor vehicle according to claim 1, characterized by, that the switch arrangement (5) is designed such that in the first switching state the traction battery (4) is electrically connected to the drive unit (2) and electrically disconnected from the solar cell arrangement (8) and / or that in the second switching state the traction battery (4) is electrically disconnected from the drive unit (2) and electrically connected to the solar cell arrangement (8). [3] Motor vehicle according to any of the preceding claims, characterized by , that the switch arrangement (10) is electrically controlled and is in the first switching state when supplied with a switching current and in the second switching state when not supplied with the switching current. [4] Motor vehicle according to any of the preceding claims, characterized by, that the switch arrangement (5) has an electrically controlled magnetic coil for magnetic displacement of a busbar, wherein the busbar is electrically connected on the one hand to the traction battery (4) and on the other hand to the drive unit (2) in the first switching state and to the solar cell arrangement (8) in the second switching state. [5] Motor vehicle according to any one of the preceding claims, characterized by, that the switch arrangement (5) has a first switch (6) which has a first switching terminal (13) electrically connected to the traction battery (4), a second switching terminal (14) electrically connected to the solar cell arrangement (8) and a third switching terminal (15) electrically connected to the drive unit (2), wherein the first switch (6) is in a first switching position in the first switching state and in a second switching position in the second switching state, wherein the third switching terminal (15) is electrically connected to the first switching terminal (13) and electrically disconnected from the second switching terminal (14) in the first switching position and is electrically disconnected from the first switching terminal (13) and electrically connected to the second switching terminal (14) in the second switching position. [6] Motor vehicle according to any one of the preceding claims, characterized by, that the switch arrangement (5) has a second switch (7) which has a first switching terminal electrically connected to the third switching terminal (15) of the first switch (6) and a second switching terminal electrically connected to the drive unit (2), or which has a first switching terminal electrically connected to the traction battery (4), a second switching terminal electrically connected to the solar cell arrangement (8) and a third switching terminal electrically connected to the drive unit (2), wherein the second switch (7) is in a first switching position in the first switching state and in a second switching position in the second switching state,wherein the third switching terminal is electrically connected to the first switching terminal and electrically disconnected from the second switching terminal in the first switching position, and electrically disconnected from the first switching terminal and electrically connected to the second switching terminal in the second switching position. [7] Motor vehicle according to any of the preceding claims, characterized by , that an electrical intermediate storage device (9) is electrically connected to the solar cell arrangement (8), wherein the electrical intermediate storage device (9) is electrically connected to the solar cell arrangement (8) in the first switching state of the switch arrangement (5) and is electrically disconnected from the solar cell arrangement (8) in the second switching state of the switch arrangement (5). [8] Motor vehicle according to any of the preceding claims, characterized by, that the electrical intermediate storage device (9) can be electrically connected to the drive device (2) when the first switching state of the switch arrangement (5) is present. [9] Method for operating a motor vehicle (1), in particular a motor vehicle (1) according to one or more of the preceding claims, wherein the motor vehicle (1) has an electric drive unit (2), a traction battery (4) electrically connected to the drive unit (2) via a switch arrangement (5) and a solar cell arrangement (8) for providing electrical energy, characterized by , that the solar cell arrangement (8) is electrically connected to the traction battery (4) via the switch arrangement (5), wherein in a first switching state of the switch arrangement (5) the drive mechanism (2) is electrically connected and in a second switching state of the switch arrangement (5) the solar cell arrangement (8) is electrically connected to the traction battery (4). [10] Computer program product comprising instructions that cause the motor vehicle (1) according to one or more of claims 1 to 8 to perform the method according to claim 9.

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