A battery hybrid vehicle with a switchable electric energy source

Abstract

A battery hybrid vehicle (100) has an electric motor (318) for propelling the battery hybrid vehicle (100), an electric energy storage (304) in terms of a battery configured to provide electric energy to the electric motor (318), an electric energy source (344) configured to provide electric energy to the electric motor (318), an input device (346) for selecting a hybrid mode or a battery only mode as an operation mode of the battery hybrid vehicle (100), and a control unit (114) configured to receive a selection of an operation mode, activate the electric energy source (344) if the hybrid mode is selected as operation mode and deactivate the electric energy source (344) if the battery only mode is selected as operation mode.

Description

A BATTERY HYBRID VEHICLE WITH A SWITCHABLE ELECTRIC ENERGY SOURCEFIELD

[0001] The present disclosure relates generally to a battery hybrid vehicle.BACKGROUND

[0002] A battery hybrid vehicle is an electric vehicle having a battery and an additional electric energy source to provide electric energy for propelling the vehicle. The additional electric energy source may comprise a battery, a capacitor, a generator or a fuel cell, for example. The electric energy source provides electric energy to at least one electric motor to propel the battery hybrid vehicle and to operate other electric consumers such as a fan or an electric heater. The electric components are electrically connected by a common link. The at least one electric motor may be operated in a generator mode for recuperative braking of the battery hybrid vehicle. The battery is configured to be operable as a buffer and can be charged by electric energy. The battery can be charged if more electric energy is supplied than consumed.BRIEF SUMMARY

[0003] It is an objective to provide a battery hybrid vehicle that is configured to activate or deactivate the additional electric energy source based on user inputs. Hence, an operator of the battery hybrid vehicle can decide on his own when to use the electric energy source. For example, the operator may decide to deactivate the electric energy source for saving energy costs or protecting the electric energy source. Or he may activate the electric energy source for providing additional electric energy for high power operations of the battery hybrid vehicle.

[0004] According to an aspect of the invention there is provided a battery hybrid vehicle comprising an electric motor for propelling the battery hybrid vehicle, an electric energy storage in terms of a battery configured to provide electric energy to the electric motor, an electric energy source configured to provide electric energy to the electric motor and an input device for selecting a hybrid mode or a battery only mode asan operation mode of the battery hybrid vehicle and a control unit. The control unit is configured to receive a selection of an operation mode, activate the electric energy source if the hybrid mode is selected as operation mode, and deactivate the electric energy source if the battery only mode is selected as operation mode.

[0005] The battery hybrid vehicle may be an agricultural vehicle such as a tractor, a harvester, a combine, a sprayer, etc., optionally connected with an implement. The battery hybrid vehicle may be configured as a hybrid electric vehicle (HEV) having a battery as electric energy storage and an additional electric energy source both for providing electric energy to the electric motor when operated in motor mode. The electric energy storage and / or the electric energy source may also supply any other electric consumer of the battery hybrid vehicle with electric energy. The electric motor may also be operated in generator mode, for example during recuperative braking of the battery hybrid vehicle. The electric energy storage may be a passive energy storage without any active control of the (de-)charge power. The electric energy storage may be used as a bufferto compensate electric imbalances. The control unit may control any electric components of the battery hybrid vehicle such as the electric motor (e. g. the inverter) or any electric consumer. The operator of the battery hybrid vehicle may select the battery only mode to deactivate the electric energy source, for example to save energy costs or protecting the electric energy source. For example in agricultural applications, it is possible to have an increased concentration of harmful gases to a fuel cell in the intake air, like ammonia or sulfur. So, the operator may select the battery only mode to prevent the fuel cell from damage due to driving through a barn with a high concentration of harmful gases. The operator may select the hybrid mode to activate the electric energy source again when he has left the barn. The hybrid mode may also be selected for providing additional electric energy for high power operations of the battery hybrid vehicle. The different operation modes may be selected by the input device. For example, the input device may comprise a button, a switch or a speech recognition system for switching of the different operation modes. The button or the switch may be implemented as a virtual input element of a graphical user interface (GUI).

[0006] The electric energy source may comprise a fuel cell.

[0007] Alternatively, the electric energy source may comprise an electric generator or any other component controllable by the control unit and configured to provide electric energy.

[0008] The control unit may select the battery only mode at vehicle start-up.

[0009] An activation of the battery only mode at vehicle start-up may be beneficial for various scenarios, e. g. if the vehicle should only be moved some meters away from the actual position. A start-up process and / or a shutdown process of a fuel cell will last disproportional long and will waste expensive energy unnecessarily. Or, the operator may intend to do some small workjust with the battery only mode as this electric energy may be cheaper than the energy of the additional energy source.

[0010] The control unit may be configured to determine a boundary condition, and to activate or to deactivate the electric energy source in dependence of the boundary condition irrespectively of the selected operation mode.

[0011] The boundary condition may be stored in a memory of the control unit. There may be a boundary condition for operating the battery hybrid vehicle 100 in hybrid mode and a different boundary condition for operating the battery hybrid vehicle 100 in battery only mode. If an operation mode has been selected, the control unit may check whetherthe boundary condition for operating the battery hybrid vehicle 100 in the selected operation mode is fulfilled. If the boundary condition is fulfilled, the control unit may control the electric energy source according to the selected operation mode. If not, the control unit 114 may control the electric energy source so that a conflict with the boundary condition can be avoided.

[0012] The boundary condition may require at least one of a sufficient state of health (SOH) of the electric energy storage, a sufficient state of charge (SOC) of the electric energy storage, a sufficient temperature of the electric energy storage, faultlessness of the electric energy source, readiness of the electric energy source, a sufficient fuel (e. g. hydrogen) supply or freedom of leakage of fuel.

[0013] For example, sufficient state of health (SOH) of the electric energy storage or a sufficient state of charge (SOC) of the electric energy storage may be required to enable the battery only mode of the battery hybrid vehicle and to allow a deactivation of the electric energy source. For example, a sufficient fuel (e. g. hydrogen) supply or freedomof leakage of fuel may be required to enable the hybrid mode of the battery hybrid vehicle and to allow an activation of the electric energy source.

[0014] The control unit may be configured to activate the electric energy source if the boundary condition is fulfilled.

[0015] When the control unit detects that the hybrid mode has been selected, the control unit may check whether the boundary conditions for operating the battery hybrid vehicle 100 are fulfilled.

[0016] The control unit may be configured to ignore the selected operation mode if the boundary condition is not fulfilled.

[0017] For example, the control unit may ignore a selected battery only mode if the state of health of the electric energy storage is not sufficient or if the required electric energy to propel the battery hybrid vehicle cannot be provided by the electric energy storage alone. For example, the control unit may ignore a selected hybrid mode if the electric energy source cannot be supplied with fuel or if a leakage of fuel has been detected. The control unit may ignore the selected operation mode as long as the at least one boundary condition is not fulfilled. The control unit may be configured to automatically accept the selected operation mode when the at least one boundary condition is fulfilled.

[0018] The control unit may be configured to switch from the selected operation mode to the other operation mode if the boundary condition prevents an operation of the battery hybrid vehicle in the selected operation mode.

[0019] The control unit may also indicate the automatic switchingto the other operation mode to the operator, e. g. by providing an optical and / or acoustic signal.

[0020] The input device may be configured to set an energy level to be provided by the electric energy source being lower than a required energy level for the propulsion of the battery hybrid vehicle.

[0021] For example, the input device may comprise a potentiometer or a slider for setting the energy level. The potentiometer or a slider may be implemented as a virtual input element. The operator may adjust the input device to set an energy level between 0% and 100% to be provided by the electric energy source for the propulsion of the vehicle. The set energy level may correspond to an energy level to be provided by theelectric energy source when the hybrid mode is active. For example, the operator may set an energy level of 70%.

[0022] The control unit may be configured to control the electric energy source to provide electric energy according to the set energy level to be provided by the electric energy source. The electric energy storage may be configured to provide electric energy according to a difference between the required energy level for the propulsion of the battery hybrid vehicle and the set energy level to be provided by the electric energy source.

[0023] For example, the energy level may be set by the operator to 70%. The control unit may receive the value of the energy level from the input device. In response thereof, the control unit may control the electric energy source to provide 70% of the total electric energy required for the propulsion of the battery hybrid vehicle. Then, the electric energy storage would provide the remaining 30% of the total electric energy required for the propulsion of the battery hybrid vehicle. I. e., as long as the energy level is set below 100%, the electric energy storage will be discharged over time. Hence, the operator may control the discharge of the electric energy storage by setting a corresponding energy level.

[0024] The control unit may be configured to control the electric energy source to provide electric energy according to the set energy level to be provided by the electric energy source if the hybrid mode may be selected as operation mode.

[0025] Another aspect includes a method for switching the activation of an electric energy source of a battery hybrid vehicle. The method comprises steps for receiving a selection of an operation mode, activating the electric energy source if a hybrid mode is selected as operation mode, and deactivating the electric energy source if a battery only mode is selected as operation mode.

[0026] As disclosed above, the control unit is configured to execute different actions. Each action may be implemented as one or more method steps of the method executable by the control unit. Hence, each action for which the control unit is configured to execute may be defined as a method step.

[0027] Within the scope of this application it should be understood that the various aspects, embodiments, examples and alternatives set out herein, and individual features thereof may be taken independently or in any possible and compatiblecombination. Where features are described with reference to a single aspect or embodiment, it should be understood that such features are applicable to all aspects and embodiments unless otherwise stated or where such features are incompatible.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Several aspects of the invention will now be described, byway of example only, with reference to the accompanying drawings, in which:

[0029] FIG. 1 illustrates a battery hybrid vehicle.

[0030] FIG. 2 illustrates a simplified view of a control unit.

[0031] FIG. 3 illustrates a schematic block diagram of the battery hybrid vehicle.

[0032] FIG. 4 illustrates a flow chart of a method executable by the control unit of FIG. 2.DETAILED DESCRIPTION

[0033] FIG. 1 shows an electrically powered battery hybrid vehicle 100 comprising front wheels 102 and rear wheels 104. An electric motor 318 (see FIG. 3) installed in the battery hybrid vehicle 100 may generate a tractive force to propel the front and / or rear wheels 102, 104. The battery hybrid vehicle 100 may be a vehicle or a vehicleimplement combination. The implement may be fixed to the vehicle or detachably connected with the vehicle. The vehicle may be an agricultural vehicle such as a tractor, a harvester, a combine, a sprayer or of any other type such as a truck. The implement may be used for an operation in an agricultural field and may be of the type of a plough, a rake, a planter, a sprayer, a mower, a trailer, etc. Depending on the type of the implement, the implement may comprise one or more tools such as a rake rotor, a mower knife, a seeding unit, a spray nozzle, a shovel, a dumper, etc.

[0034] The battery hybrid vehicle 100 is exemplarily designed as a fuel cell vehicle having an electric energy source 344 with a fuel cell 306 (see FIG. 3). Alternatively, the battery hybrid vehicle 100 may be of a different type having an electric energy source 344 with a generator, a capacitor or any other component for providing electric energy.The fuel cell 306 can be supplied with fuel such as hydrogen or methane stored in tanks 110. The battery hybrid vehicle 100 may comprise five tanks, for example. The tanks 110 are arranged in an enclosure 112 attached on top of a cabin 108 of the battery hybrid vehicle 100. An operator may sit in the cabin 108 of battery hybrid vehicle 100 and manually control the battery hybrid vehicle 100.

[0035] The battery hybrid vehicle 100 comprises also a control unit 114. The control unit 114 as shown in FIG. 2 in more detail may be installed anywhere in the battery hybrid vehicle 100, for example under the hood 106.

[0036] FIG. 2 shows the control unit 114 comprising an I / O interface 202, a controller 204 and a memory 206. The I / O interface 202, the controller 204 and the memory 206 may be attached to a printed circuit board (PCB). The control unit 114 may receive and send signals or data via the I / O interface 202. The I / O interface 202 may be a wireless interface or a connector. The controller 204 may store the data or signals received by the control unit 114 in the memory 206. The memory 206 may contain additional data or executable computer program products, for example in terms of a computer- implemented method, that may be retrieved, processed or executed by the controller 204. Data or signals resulting from the processing of data or signals or from the execution of a computer program product may be stored to the memory 206 or sent to the I / O interface 202 by the controller 204.

[0037] FIG. 3 shows a simplified block diagram of the battery hybrid vehicle 100 shown in FIG. 1 . Additionally to the components shown in FIG. 1 , the battery hybrid vehicle 100 comprises several components that are electrically connected with each other such as a power distribution unit 302 (PDU), an electric energy storage 304 (e. g. a battery) configured to provide electric energy to the electric motor 318, the electric energy source 344 configured to provide electric energy to the electric motor 318, a DC / DC converter 308 arranged between the electric energy source 344 and the power distribution unit 302, a first electric consumer 310, a second electric consumer 312, an inverter 314, the electric motor 318, a third electric consumer 316, a fourth electric consumer 322, another DC / DC converter 326 connected with a first on-board power supply 328, another DC / DC converter 330 connected with a second on-board power supply 332, an on-board charging device 334, and additional consumers such as an AC compressor 340, an air compressor 342 and an input device 346 for selecting a hybridmode or a battery only mode as an operation mode of the battery hybrid vehicle 100. As mentioned above, the electric energy source 344 comprises the fuel cell 306.

[0038] The inverter 314 is electrically connected with the electric motor 318 and controls the modes of operation of the electric motor 318. When the electric motor 318 is operated in a motor mode, the electric motor 318 converts electric energy into mechanical energy for providing a torque to drive a transmission 320 mechanically coupled to the electric motor 318. The transmission 320 may be an automatic gearbox such as a continuous variable transmission (CVT). From the transmission 320, the torque is transferred to the front and / or rear wheels 102, 104 to drive the battery hybrid vehicle 100. When the electric motor 318 is operated in a generator mode, the electric motor 318 converts a torque transferred from the transmission 320 into electric energy. The electric motor 318 may be operated in generator mode for recuperative braking of the battery hybrid vehicle 100. The electric energy generated by the electric motor 318 operated in generator mode may be used to supply any electric component of the battery hybrid vehicle 100 and / or to charge the electric energy storage 304. 1, e., the electric motor 318 as well as the electric energy storage 304 or the fuel cell 306 may be used as an electric energy source.

[0039] The first electric consumer 310 is a brake resistor to consume excessive electric energy generated by the electric motor 318 operated in generator mode that cannot be saved by the electric energy storage 304. The first electric consumer 310 may protect the power management system 300 from damage in error cases, for example in a load drop scenario. The second electric consumer 312 is a fan for cooling electric components and protect them against overheating. The third electric consumer is a positive temperature coefficient (PTC) resistance installed in the cabin 108 and used for climatization of the cabin 108 (heating) together with the AC compressor 340. The fourth electric consumer 322 is an indirect electric consumer in terms of a retarder mechanically coupled to the electric motor 318 via the transmission 320 for decelerating the battery hybrid vehicle 100 by providing a brake torque for braking the wheels. The brake torque induced by the fourth electric consumer 322 has effect on the electric motor 318 to consume electric energy.

[0040] The additional DC / DC converters 326 and 332 connected with the power distribution unit 302 may provide different voltage values for the first on-board powersupply 328 and the second on-board power supply 332. For example, the first on-board power supply 328 may provide 12 V and the second on-board power supply 332 may provide 24 V. Additionally, a charging receptacle 336 is connected via a 3-phase onboard charging device 334 (OBC) with the power distribution unit 302. The charging receptacle 336 may be connected with an external electric energy source, e. g. a wallbox, to supply the power distribution unit 302 with electric energy and to charge the electric energy storage 304.

[0041] The electric energy source 344 with the fuel cell 306 and the electric motor 318 are covered by a hood 106 of the battery hybrid vehicle 100. The tanks 110 are fluidly connected with the fuel cell 306 and a refilling receptacle 338 by means of a hydraulic line. Via the refilling receptacles 338, the tanks 110 can be refilled with fuel at a gas station. From the tanks 110, the fuel can be delivered via the hydraulic line to the fuel cell 306. A pressure reduction valve 324 arranged in the hydraulic line between the fuel cell 306 and the tanks 110 can be used to adjust the pressure level of the fuel delivered to the fuel cell 306. For example, a pressure of 700 bar within the tanks 110 may be reduced to 12 bar when hydrogen is provided to the fuel cell 306. The fuel cell 306 can convert the chemical energy of the fuel into electric energy to supply any electric component of the battery hybrid vehicle 100 and / or to charge the electric energy storage 304. Hence, the fuel cell 306 can generate electric energy for the electric motor 318 to provide the tractive force. The DC / DC converter 308 arranged between the fuel cell 306 and the power distribution unit 302 converts the voltage of the electric current provided by the fuel cell 306 to a voltage value of the electric energy storage 304, as for example any value between 550 V to 750 V. The fuel cell 306 may be a proton exchange membrane (PEM) fuel cell.

[0042] The battery hybrid vehicle 100 can be operated in a battery only mode or in a hybrid mode. In the hybrid mode, both the electric energy storage 304 and the electric energy source 344 can provide electric energy to the electric motor 318 for propelling the battery hybrid vehicle 100. In the battery only mode, the electric energy source 344 is prevented by the control unit 114 to supply electric energy to the electric motor 318 so that the electric motor 318 is supplied with electric energy provided by the electric energy storage 304 only. But the electric energy source 344 may optionally supplyelectric energy to consumers other than the electric motor 318 in the battery only mode.

[0043] The input device 346 may comprise a button or a switch for manually selecting an operation mode of the battery hybrid vehicle 100. The operator may select the battery only mode if he intends to drive the battery hybrid vehicle 100 with electric energy provided by the electric energy storage 304 only. Or he may select the hybrid mode if he intends to drive the battery hybrid vehicle 100 with electric energy provided by both the electric energy storage 304 and the electric energy source. The input device 346 also comprises an input element to set an energy level to be provided by the electric energy source 344 when the battery hybrid vehicle 100 is operated in hybrid mode. The energy level may define a ratio of the electric energy to be supplied by the electric energy source 344 and the electric energy storage 304 to provide in sum the total electric energy required for the propulsion of the battery hybrid vehicle 100. The input element may be a potentiometer or a slider which may be optionally implemented in form of a virtual input element. The energy level can be set between 0% and 100% to demand an electric energy supply of the electric energy source 344 being lower than a required energy supply for the propulsion of the battery hybrid vehicle. For example, the operator may adjust the input device 346 to set an energy level of 70% to demand an electric energy supply of the electric energy source 344 for providing 70% of the total electric energy required to propel the battery hybrid vehicle 100 and an electric energy supply of 30% of the total electric energy required to propel the battery hybrid vehicle 100 to be supplied from the electric energy storage 304. The total electric energy required to propel the battery hybrid vehicle 100 may depend on different factors such as the vehicle speed, slope of the road, wind speed, and other resistances.

[0044] The control unit 114 is integrated in the power distribution unit 302 and can send and / or receive electrical signals via the I / O interface 202 to / from the components of the battery hybrid vehicle 100 (see FIG. 2 and FIG. 3). The control unit 114 can also receive signals from the input device 346, such as the selected operation mode and / or the energy level of the electric energy source 344 demanded by the operator. Alternatively, the control unit 114 can be arranged external to the power distribution unit 302.

[0045] FIG. 4 shows a flow chart of a method for switching the activation of an electric energy source 344. The method may be at least partly a computer-implemented method stored as a computer program product in the memory 206 of the control unit 114. The control unit 114 is configured to carry out the method. Computer- implemented parts of the method may be executed by the controller 204 of the control unit 114. Non-computer-implemented parts of the method may be executed manually or by other components of the system. The method is described by way of example of several steps without any restriction in respect of the steps. That is, the number or the order of steps may be adapted, for example single steps may be excluded and / or added and executed earlier or later than described. When the method proceeds from one step to a next step, the previous step may still be active so that both the one and the next step may be executed in parallel. Accordingly, the control unit may execute two or more method steps in parallel.

[0046] The method starts with step S101 , for example when the operator starts up the battery hybrid vehicle 100.

[0047] The method proceeds to step S102 and the control unit 114 selects a predefined operation mode. The predefined operation mode is stored in the memory 206 of the control unit 114. For example, the battery only mode is defined as the predefined operation mode. Alternatively, the hybrid mode can be defined as the predefined operation mode. If the hybrid mode is defined as the predefined operation mode, the control unit 114 also sets the energy level for electric energy source 344. Then, the control unit 114 controls the electric energy source 344 according to the selected predefined operation mode. If the battery only mode is the predefined operation mode, then the control unit 114 avoids to activate or deactivates the electric energy sources 344. If the hybrid mode is the predefined operation mode, then the control unit 114 activates the electric energy source 344 and controls the electric energy source 344 to supply the electric motor 318 with a proportion of the total electric energy required for the propulsion of the battery hybrid vehicle 100 according to the energy level. The remaining proportion of the total electric energy required for the propulsion can be drawn from the electric energy storage 304.

[0048] The method proceeds to step S103 and the control unit 114 receives from the input device 346 a set energy level to be provided by the electric energy source 344. Forexample, the operator may has set an energy level of 70% of the total electric energy required for propulsion of the battery hybrid vehicle 100.

[0049] The method proceeds to step S104 and the control unit 114 determines all information required for checking the fulfillment of the boundary condition. For example, the control unit 114 receives a current state of health (SOH) of the electric energy storage 304, a current state of charge (SOC) of the electric energy storage 304, a current temperature of the electric energy storage 304, an error status report of the electric energy source 344, a readiness status signal of the electric energy source 344, a current rate of fuel (e. g. hydrogen) supply or a current rate of a leakage of fuel, and / or other information. The control unit 114 determines also the total electric energy required for propelling the battery hybrid vehicle 100.

[0050] The method proceeds to step S105 and the control unit 114 checks whether the operator has operated the input device 346 to switch the operation mode for the battery hybrid vehicle 100. The operator may select with the input device 346 the battery only mode or the hybrid mode as operation mode. Alternatively, the operator may decide not to switch the operation mode. The control unit 114 receives a corresponding signal form the input device 346. If the operator has selected the battery only mode or the hybrid mode as operation mode, the method proceeds to step S106. If the operator has not switched the operation mode, the method proceeds to step S111 .

[0051] At step S106, the control unit 114 checks depending on the selected operation mode by the operator whetherthe boundary condition forthe selected operation mode is fulfilled. The control unit 114 may compare any determined information at step S104 with the applicable boundary condition forthe selected operation mode. For example, when the battery only mode has been selected by the input device 346 as operation mode, the control unit 114 may check whetherthe electric energy required for propelling the battery hybrid vehicle 100 can be provided by the electric energy storage 304 only. The control unit 114 may also check whether the current state of health (SOH) of the electric energy storage 304, the current state of charge (SOC) of the electric energy storage 304 and / or the current temperature of the electric energy storage 304 are sufficient for the battery only mode. Alternatively, when the hybrid mode has been selected by the input device 346 as operation mode, the control unit 114 may check whether the error status report of the electric energy source 344 does not indicate anyerror, the readiness status signal of the electric energy source 344 indicates readiness of the electric energy source 344, the electric energy source 344 can provide the electric energy for propelling the battery hybrid vehicle 100 according to the selected energy level, the current rate of fuel (e. g. hydrogen) supply is sufficient and / or the current rate of a leakage of fuel is negligible low, for example. If the boundary condition is not fulfilled, the control unit 114 ignores the manual selection of the operation mode and the method proceeds with step S103 again as described above. If the boundary condition is fulfilled, the method proceeds with step S107.

[0052] At step S107, the control unit 114 accepts the manual selection of the operation mode and switches the operation mode accordingto the selection of the operator as determined at step S105. If the operator has switched the input device 346 to the battery only mode, the control unit 114 selects the battery only mode. If the operator has switched the input device 346 to the hybrid mode, the control unit 114 selects the hybrid mode. Then, the method proceeds to step S108.

[0053] At step S108, the control unit 114 checks whether the hybrid mode has been selected. If so, the method proceeds to step S109. If not, then the battery only mode has been selected and the method proceeds to step S110.

[0054] At step S109, the control unit 114 activates the electric energy source 344. Additionally, the control unit 114 controls the electric energy source 344 to provide electric energy according to the set energy level as determined at step S103. Based on the total electric energy required for propelling the battery hybrid vehicle 100 (as determined at step S104), the control unit 114 may determine the proportion of the electric energy to be provided by the electric energy source 344. For example, the control unit 114 may control the electric energy source 344 to provide 70% of the total electric energy required for the propulsion of the battery hybrid vehicle 100 if the operator has set an energy level of 70%. The remaining 30% of the total electric energy may be drawn by the electric motor 318 from the electric energy storage 304. Thus, the electric motor 318 will be supplied in sum with 100% of the total electric energy required for propelling the battery hybrid vehicle 100. Then, the method proceeds with step S113.

[0055] At step S110, the control unit 114 deactivates the electric energy source 344 due to the selected battery only mode. Thus, the total electric energy required for thepropulsion of the battery hybrid vehicle 100 is provided by the electric energy storage 304. Then, the method proceeds to step S113.

[0056] If the operator has not switched the operation mode by the input device 346, the method proceeds after step S105 with step S111 . At step S111 , the control units 114 checks depending on the active operation mode of the battery hybrid vehicle 100 whether the boundary condition is still fulfilled. Analogously to step S106, the control unit 114 may compare any determined information at step S104 with the applicable boundary condition for the active operation mode. For example, when the battery only mode is activated as operation mode, the control unit 114 may check whetherthe electric energy required for propelling the battery hybrid vehicle 100 can be provided by the electric energy storage 304 only. The control unit 114 may also check whether the current state of health (SOH) of the electric energy storage 304, the current state of charge (SOC) of the electric energy storage 304 and / or the current temperature of the electric energy storage 304 are sufficient for the battery only mode. Alternatively, when the hybrid mode is activated as operation mode, the control unit 114 may check whether the error status report of the electric energy source 344 does not indicate any error, the readiness status signal of the electric energy source 344 indicates readiness of the electric energy source 344, the electric energy source 344 can provide the electric energy for propelling the battery hybrid vehicle 100 according to the selected energy level, the current rate of fuel (e. g. hydrogen) supply is sufficient and / or the current rate of a leakage of fuel is negligible low, for example. If the boundary condition is fulfilled, the method proceeds with step S103 again (as described above). If the boundary condition is not fulfilled, the method proceeds with step S1112.

[0057] At step S112, the control unit 114 selects automatically the other operation mode to switch from the active operation mode to the inactive operation mode since the boundary condition for the active operation mode is not fulfilled any more. I. e., the control unit 114 selects the battery only mode as operation mode if the boundary condition of the activated hybrid mode cannot be fulfilled. Analogously, the control unit 114 selects the hybrid mode as operation mode if the boundary condition of the activated battery only mode cannot be fulfilled. The control unit 114 may select the other operation mode irrespectively of the operation mode selected by the input device 346. Hence, the control unit 114 ensures that an operation mode is selected whoseboundary condition is fulfilled. Then, the method proceeds to step S108 as disclosed above.

[0058] At step S113, the control unit 114 checks whether the battery hybrid vehicle100 is still running. If so, the method proceeds with step S103 again. If not, the method proceeds to step S114.

[0059] At step S114, the method ends. The method may be restarted again with step S101 and proceed as described above.

[0060] All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.LISTING OF DRAWING ELEMENTS100 battery hybrid vehicle 306 fuel cell102 front wheel 308 DC / DC converter104 rear wheel 310 first electric consumer106 hood 312 second electric consumer108 cabin 314 inverter110 tank 316 third electric consumer112 enclosure 318 electric motor114 control unit 320 transmission202 I / O interface 322 fourth electric consumer204 controller 324 pressure reduction valve206 memory 326 DC / DC converter300 power management system 328 on-board power supply302 power distribution unit 330 DC / DC converter304 electric energy storage 332 on-board power supplyon-board charging device charging receptacle refilling receptacle AC compressor air compressor electric energy source input device

Claims

CLAIMSWhat is claimed is:1 . A battery hybrid vehicle (100) comprising an electric motor (318) for propelling the battery hybrid vehicle (100); an electric energy storage (304) in terms of a battery configured to provide electric energy to the electric motor (318); an electric energy source (344) configured to provide electric energy to the electric motor (318); and an input device (346) for selecting a hybrid mode or a battery only mode as an operation mode of the battery hybrid vehicle (100); and a control unit (114) configured to receive a selection of an operation mode; activate the electric energy source (344) if the hybrid mode is selected as operation mode; and deactivate the electric energy source (344) if the battery only mode is selected as operation mode.

2. The battery hybrid vehicle (100) of claim 1 , wherein the electric energy source (344) comprises a fuel cell (306).

3. The battery hybrid vehicle (100) of claim 1 or 2, wherein the control unit (114) selects the battery only mode at vehicle start-up.

4. The battery hybrid vehicle (100) of any one of claims 1 to 3, wherein the control unit (114) is configured to determine a boundary condition; and activate or deactivate the electric energy source (344) in dependence of the boundary condition irrespectively of the selected operation mode.

5. The battery hybrid vehicle (100) of claim 4, whereinthe boundary condition requires at least one of a sufficient state of health of the electric energy storage (304), a sufficient state of charge of the electric energy storage (304), a sufficient fuel supply or freedom of leakage of fuel.

6. The battery hybrid vehicle (100) of claim 4 or 5, wherein the control unit (114) is configured to activate the electric energy source (344) if the boundary condition is fulfilled.

7. The battery hybrid vehicle (100) of any one of claims 4 to 6, wherein the control unit (114) is configured to ignore the selected operation mode if the boundary condition is not fulfilled.

8. The battery hybrid vehicle (100) of any one of claims 4 to 7, wherein the control unit (114) is configured to switch from the selected operation mode to the other operation mode if the boundary condition prevents an operation of the battery hybrid vehicle (100) in the selected operation mode.

9. The battery hybrid vehicle (100) of any one of the preceding claims, wherein the input device (346) is configured to set an energy level to be provided by the electric energy source (344) being lower than a required energy level for the propulsion of the battery hybrid vehicle (100).

10. The battery hybrid vehicle (100) of claim 9, wherein the control unit (114) is configured to control the electric energy source (344) to provide electric energy according to the set energy level to be provided by the electric energy source (344); wherein the electric energy storage (304) is configured to provide electric energy according to a difference between the required energy level for the propulsion of the battery hybrid vehicle (100) and the set energy level to be provided by the electric energy source (344).11 . The battery hybrid vehicle (100) of claim 10, whereinthe control unit (114) is configured to control the electric energy source (344) to provide electric energy according to the set energy level to be provided by the electric energy source (344) if the hybrid mode is selected as operation mode.

12. A method for switching the activation of a electric energy source (344) of a battery hybrid vehicle (100), comprising: receive a selection of an operation mode; activate the electric energy source (344) if a hybrid mode is selected as operation mode; and deactivate the electric energy source (344) if a battery only mode is selected as operation mode.

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