DE102004009947A1 - Hydrogen-oxygen fuel cell hybrid drive in particular for sailing boat, to be operated under two different conditions - Google Patents

Abstract

The hybrid drive comprises an arrangement of hydrogen-oxygen fuel cells (1), a battery (2), and at least one motor (4), all connected by an electrical power transformer unit (3, 5) as well as an electronic control and monitoring system (6) for the use of the hydrogen-oxygen fuel cells (1), the motor (4), and the battery (2). The control system (6) can initiate a first operating condition using the hydrogen-oxygen fuel cell arrangement (1) for charging the battery (2) or a second condition with a fully charged battery (2) and the motor (4) driven by the hydrogen-oxygen fuel cell arrangement (1) with the required energy supply.

Description

The The invention relates to a fuel cell hybrid drive, in particular for a Watercraft, in particular as an auxiliary drive for a sailing watercraft, according to the preamble of claim 1, and a method of operation such according to the preamble of claim 9.

For one environmentally friendly propulsion of a watercraft, in particular as Auxiliary drive for one Sailing watercraft, are increasingly fuel cell hybrid drives. Such a fuel cell hybrid drive comprises a fuel cell arrangement, a drive battery and at least one drive motor, wherein the fuel cell assembly, the drive battery and the drive motor via a electrical power converter arrangement are coupled together and an electronic control and monitoring system for operation the fuel cell assembly, the drive motor and the drive battery, also for no further details here designated tasks is provided.

The Fuel cell assembly typically includes fuel cells with proton exchange membrane (PEM) operating in the low temperature range of about 65 ° Celsius are operable and therefore, compared to the high operating temperature of molten carbonate fuel cells at about 650 ° C, also referred to as "cold" fuel cells.

A Difficulty in such a fuel cell hybrid drive is that on the one hand in most applications the current output of the fuel cell for a full load operation of Drive motor is insufficient and on the other hand, the capacity of the drive battery is limited, so it is unfavorable make due to the high current consumption of the drive motor soon to a performance bottleneck can come.

The The object of the invention is therefore a fuel cell hybrid drive indicate, in which the fuel cell assembly, drive battery and the drive motor to be configured as possible always optimal performance is available.

Farther intended by the invention, a corresponding method for operation be specified of such a fuel cell hybrid drive.

The Asked object is by a fuel cell hybrid drive with the features of claim 1 and by a method of operation such a fuel cell hybrid drive with the features of claim 9 solved.

advantageous Further developments of the invention are. specified in the respective subclaims.

By The invention will be a fuel cell hybrid drive, in particular for a Watercraft, in particular as an auxiliary drive for a sailboat with a fuel cell assembly, a drive battery and at least created on a drive motor. The fuel cell assembly, the The drive battery and the drive motor are via an electrical power converter assembly coupled with each other and it is an electronic control and surveillance system for the Operation of the fuel cell assembly, the drive motor and the Drive battery provided. According to the invention, the control and monitoring system to carry out a first operating state of the fuel cell hybrid drive, in which when not fully charged drive battery and optional existing (or nonexistent) current consumption of the drive motor an operation of the fuel cell assembly with set to full load Current is given to charge the drive battery, and a second Operating state, in which at fully charged drive battery and existing current consumption of the drive motor, an operation of Fuel cell assembly with according to the load requirement of Drive motor set current specification takes place.

One significant advantage of the fuel cell hybrid drive according to the invention is it that charging the not fully charged drive battery in the fastest possible Time is going on, so with a possible load request by the drive motor the full capacity of the drive battery soon again available stands. Another advantage is that when fully charged Drive battery by adjusting the current specification of the fuel cell assembly to the actual Power requirement of the drive motor maximum fuel economy given is.

According to one preferred embodiment of Fuel cell hybrid drive according to the invention is the control and monitoring system for execution the first operating state with set to full load Current specification of the fuel cell assembly until it reaches a first Limit temperature of the drive battery and when the first limit temperature is exceeded the drive battery until reaching a second limit temperature, the higher than the first limit temperature, with to a reduced charging current set current specification of the fuel cell assembly is provided. As a result, the charging current as a function of the temperature reduces the drive battery, allowing overheating and overcharging the drive battery is prevented.

Especially In this case, it may be provided that the control and monitoring system to cancel the charging process of the drive battery when exceeded be provided the second limit temperature. A destruction of the battery by overloading is thereby reliably prevented.

According to one another preferred embodiment the fuel cell hybrid drive according to the invention can the control and monitoring system to carry out the second operating state with a lower than the Load request of the drive motor corresponding value set Current specification for the fuel cell assembly may be provided. Thus, advantageously even in a load range, which is covered solely by the fuel cell assembly could be taken from a minimal battery power, which in turn overcharging the Battery is avoided.

With Advantage may also be at least one backup battery for on-board and / or operating power supply to be provided via a electrical power converter assembly is chargeable. The on-board or Operating power supply is thus on the state of charge of the drive battery independently, so that all important functions even at low charge of the drive battery can be maintained.

Farther can be a network charger be provided with the drive battery and / or the backup battery via a Shore supply are rechargeable.

According to one preferred embodiment of Fuel cell hybrid drive according to the invention the drive battery is connected to a common busbar, to the fuel cell assembly via a first power converter and the drive motor over a second power converter are connected.

Finally are Advantageously, the backup battery via the power converter arrangement or also the mains charger completed to the common busbar.

Farther the invention provides a method for operating a fuel cell hybrid drive, especially for a watercraft, in particular created as an auxiliary drive for a sailing watercraft, a fuel cell assembly, a drive battery and at least contains a drive motor, wherein the fuel cell assembly, the drive battery and the Drive motor over an electrical power converter arrangement coupled together and wherein the operation of the fuel cell assembly, the drive motor and the drive battery through an electronic control and monitoring system is controlled and monitored. It is according to the invention provided that in a first operating condition at not full charged drive battery and optional (or not existing) current consumption of the drive motor, the fuel cell assembly with set to full load current specification for charging the drive battery is operated, and that in a second operating state at full charged drive battery and existing current consumption of the drive motor the fuel cell assembly with according to the load requirement the drive motor set current specification is operated.

Preferably becomes the first operating state by the control and monitoring system with set to full load operation current specification of the fuel cell assembly until reaching a first limit temperature of the drive battery and when crossing the first limit temperature of the drive battery until reaching a second limit temperature higher than the first limit temperature is, with set to a reduced charging current current specification operated the fuel cell assembly.

Preferably it is envisaged that the control and monitoring system will charge the drive battery when exceeding the second limit temperature stops.

According to one another preferred embodiment the method according to the invention it is envisaged that the second operating state is controlled by the control and surveillance system with a lower than the load request of the drive motor corresponding value set current specification for the fuel cell assembly is performed.

Farther can at least one backup battery, which provided for on-board and / or operating power supply is over an electric power converter assembly are charged.

Also can the drive battery and / or the backup battery by means of a continue intended mains charger via a Land connection to be charged.

advantageously, It can be provided that the drive battery with a common busbar is connected to the also the fuel cell assembly via a first power converter and the drive motor via a second power converter are connected.

Finally, it may be provided that also the backup battery via the power converter order or the mains charger are completed to the common busbar.

in the The following will be from embodiment of the Fuel cell hybrid drive according to the invention and a method for operating such with reference to the drawing explained.

It shows:

1 a block diagram of the overall system of a fuel cell hybrid drive according to an embodiment of the invention, in which the hybrid drive is provided as an auxiliary drive for a sailing watercraft;

2 a further block diagram of the fuel cell hybrid drive for displaying the relevant measurement and control variables of the drive;

3 a table explaining the main operating conditions occurring in the drive;

4 a first flowchart for explaining an advantageous possibility of operation of the fuel cell hybrid drive according to the described embodiment; and

5 a second flowchart for explaining another advantageous way of operating the fuel cell hybrid drive according to the described embodiment.

At the in 1 in the block diagram illustrated fuel cell hybrid drive, which is provided as a drive for a watercraft, in particular as an auxiliary drive for a sailing boat, is a fuel cell assembly formed by four fuel cell modules 1 provided, which consists of an arrangement of three hydrogen tanks 16 is supplied with hydrogen as fuel. Each of the modules of the fuel cell assembly 1 has in the illustrated embodiment, a nominal electrical power of 1.2 kW, the entire fuel cell assembly 1 So an electric power of 4.8 kW. The hydrogen is in the hydrogen tanks 16 held under a pressure of about 300 bar.

The modules of the fuel cell assembly 1 are about respective first power converters 3 to a common busbar 17 connected, with which in turn a drive battery 2 and, via a second power converter 5 , a drive motor 4 the hybrid drive are connected. The fuel cell assembly 1 thus forms together with the drive battery 2 , the drive motor 4 and by the first power converter 3 and the second power converter 5 formed power converter assembly 3 . 5 the core of the fuel cell hybrid drive of the present embodiment.

To control and monitor the fuel cell hybrid drive is an electronic control and monitoring system 6 intended. This records all parameters relevant to the operation and safety of the hybrid drive and then controls the individual components of the drive system. A display 14 serves the visualization of the essential parameters.

The first power converter 3 accomplish a conversion of the unregulated, load-dependent output voltage of the modules of the fuel cell assembly 1 from about 26 V to 43 V to a voltage of the common busbar 17 and the drive battery 2 of 96 V, the second power converter 5 is a three-phase converter, which determines the voltage of the common busbar 17 to a three-phase current for operating the drive motor 4 implements.

Furthermore, the hybrid drive includes a first backup battery 8th , which in the illustrated embodiment has a voltage of 24 V, the operating power supply of the hybrid drive is used and a power converter 10 from the common busbar 17 and a second backup battery 9 , which has a voltage of 12 V, the on-board power supply of the vessel is used and another power converter 11 also from the common busbar 17 is charged.

Finally, a network charger 7 provided, which for charging the batteries 2 . 8th . 9 is provided from a shore connection and converts the voltage of the shore connection, typically 220 V, to the busbar voltage 96V.

The electronic control and monitoring system 6 regulates the power distribution between the modules of the fuel cell assembly 1 , the drive battery 2 and the drive motor 4 and, as mentioned above, also handles the security-related tasks of the system. On the display 14 of the control and monitoring system 6 Among other things, the power output of the fuel cell assembly 1 , the drive battery 2 and the current consumption of electric power displayed and the hydrogen storage of the hydrogen tanks 16 displayed in the form of, for example, color bar charts. Furthermore, the display shows 14 Status and error messages and the state of charge and the voltage of the drive battery 2 at.

Hereinafter, the operation of the fuel cell hybrid drive is under the control the control and monitoring system 6 explained. Depending on the availability of the fuel cell of the fuel cell assembly 1 and the state of charge of the drive battery 2 on the one hand and the power requirement of the boat drive forming drive motor 4 and the on-board and on-board power supplies through the backup batteries 8th . 9 On the other hand, there are different operating states. These are provided by the control and monitoring system 6 detected and issued appropriate control signals to the individual components.

2 shows a block diagram of the fuel cell hybrid drive and the main measurement and manipulated variables in the control and monitoring system 6 are processed. The mains voltage U _mains is connected to the common busbar 17 removed, as well as from this to the motor power converter 5 for the operation of the drive motor 4 output motor current I _Mot From a battery charge control unit 18 A battery charge _{state signal} C _{Bat is} output, which should be between a nominal value C _Nenn and a lower limit C _uGW . An actuating signal I _BZ is used as a current input to the fuel cell arrangement 1 entered. An _actuating signal I _MotoGW forms the _actuating signal for that of the motor power converter 5 to the drive motor 4 delivered engine power, which is limited to an upper limit.

In the 3 shown table of operating states indicates to which values the control variables by the control and monitoring system 6 be set depending on the respective measured variables for the respective operating states.

Lines 1 and 2 of the table indicate an operating condition in which the engine is not in operation, I _Mot = 0. In row 1, the charge of the battery corresponds to the intended _rated charge, C _Bat = C _nominal . This is no current specification for the fuel cell assembly 1 before, I _BZ = 0. If an operation of the fuel cells have taken place beforehand, then these are after a certain time, for. B. switched off after 5 minutes, t = t ₁ .

If the motor is switched off, I _Mot = 0, but the charge of the battery is less than the nominal charge, C _Bat <C _rated line 2 of the table, so the battery is charged with maximum charging current, I _BZ = I _BZ-max , where the charging but only after a certain delay of z. B. 30 minutes, t> t ₂ .

If the mains voltage is greater than a predetermined maximum value, U _network > U _max , then the fuel cell current I _{BZ is} linearly reduced until U _mains <= U _max .

If the temperature of the battery exceeds a predetermined threshold, T _Bat > T _max , then the current input I _BZ for the fuel cell arrangement 1 reduced until the battery temperature is below the limit, T _Bat <= T _max .

Lines 3 and 4 show operating states in which the motor is operated, the motor current being smaller than the maximum current that can be supplied by the fuel cells, 0 <I _Mot <I _BZ-max .

If the batteries are charged up to the nominal charge, C = C _{Bat nominal,} the power requirement for the fuel cell is such that the from the fuel cells in the common busbar 17 supplied current of the current consumption of the motor from the common busbar 17 corresponds to, I _BZ = I _Mot . This means limiting the fuel cell current to the current consumed by the motor (line 3 of the table).

If the charge of the battery is less than the _rated charge, C _Bat <C _Nom (line 4 of the table), the fuel cells must be adjacent to the power to drive the drive motor 4 also a power to charge the drive battery 2 give off what is done with maximum fuel cell current, so that the current specification to the fuel cell assembly 1 maximum, I _BZ = I _BZ-max . The power not consumed by the motor is used to charge the battery, charging does not start until after a delay of a predetermined time, for example 15 minutes, t> t ₃ .

Finally, line 5 of the table shows the case that the power consumption of the engine is greater than the maximum output of the fuel cells, I _Mot > I _BZ-max . This means that in addition to the current supplied by the fuel cells, power from the drive battery 2 must be removed. Condition for this is that the capacity of the traction battery 2 is sufficient, C _Bat > C _uGW . The fuel cells are operated again with maximum current specification, I _BZ = I _BZ-max .

For the operating states shown in lines 3 to 5 of the table applies with respect to the mains voltage U _network on the common busbar 17 and the temperature T _{Bat of} the drive battery 2 the same as for the operating state described in line 2 of the table, namely that when the voltage U _net exceeds a predetermined maximum value U _max , the current command I _{BZ is} linearly reduced to the fuel cells until U _net <= U _max , and that if the temperature of the drive battery 2 T _Bat exceeds a predetermined maximum temperature, also the current input I _{BZ is} reduced for the fuel cell assembly until the battery temperature T _Bat <= T _max .

The lower limit of the battery charge C _uGW means a _{Tiefentladeschwelle} , under which the drive battery 2 may not be unloaded. When the permissible maximum temperature T _{max of} the drive battery is exceeded 2 the current specification for the fuel cells I _BZ is reduced by a constant amount and, if no improvement occurs, further linearly reduced until finally I _BZ = 0.

This in 4 Flowchart I shown shows the basic sequence of the control and monitoring system 6 carried out in the manner of a program sequence.

In program step 10 the switching on of the fuel cells takes place. In program step 12 is queried whether the battery temperature is less than the upper limit temperature HI-HI, in the illustrated embodiment, less than 60 ° C. If this is not the case, ie if the upper limit temperature HI-HI is exceeded, then an immediate switch-off takes place in the program step 20 ,

Otherwise, in the next program step 14 asked whether the battery temperature is lower than the lower limit temperature HI, less than 50 ° C in the illustrated embodiment. If this is the case, then in the next program step 16 queried whether the battery is fully charged.

If this is the case, then no power is required to charge the battery in the next program step 18 the current specification of the fuel cells is set to a value I = 0.9 × I _mot / n, where I _{Mot is} the motor current and n is the number of available fuel cells. By the factor 0.9, the current specification for the fuel cells is thus 10% lower than corresponds to the actually required motor current I _Mot , so that the difference is taken from the battery. This has the purpose to prevent overcharging or a permanent fully charged state of the battery.

But was in the program step 16 found that the battery is not fully charged, so is in the program step 22 the power requirement for the fuel cell is set to the value I = P _lim / U _batt, said _batt P _lim, the output limitation [W] per U converter and the battery voltage is. This corresponds to charging the battery with the permitted full load capacity.

Was in the previous program step 14 However, determined that the battery temperature is not less than 50 ° C, again in a further program step 24 the request whether the battery is fully charged.

If this is the case, ie no power is required to charge the battery, but only power for the motor drive, so will in the subsequent program step 28 the current specification for the fuel cells is set to a value I = 0.9 × I _Mot / (2 × n), ie to half the value of the current specification in the program step 18 , This takes into account the fact that because of the program step 14 ascertained too high battery temperature, this should only be charged with a reduced charging current, so that it can cool down.

But was in the program step 24 If the battery is not fully charged then it will branch to the program step 26 where the current command is set to a value I = P _bur / (U _batt * 2), ie to half the value of the full load current command of program step 22 , This also takes into account the fact that, due to the battery temperature, charging of the battery may only take place with reduced power.

From the program steps 18 . 22 . 26 respectively. 28 then a return to the beginning of the program takes place.

Table II shows a modification of the program flow of Table I in which respective start-up delays and additional requests for feedback from the individual in the fuel cell assembly 1 contained fuel cell modules are provided.

In the program step 40 it will first ask if the battery is fully charged.

If this is the case, then is in program step 56 asked whether the motor current I _{Mot is} greater than 8 A. This is a threshold which decides whether the fuel cells should be started despite a fully charged battery due to the comparatively high motor current.

If this is the case, then takes place in program step 58 a start of the fuel cells.

In the following program step 68 become the modules of the fuel cell assembly 1 queried after their feedback, ie a status message, whether they are ready or not.

In the event that at least the feedback of a fuel cell module is not present, ie for the (unlikely) case that none of the fuel cell modules is ready for operation, takes place in program step 76 the end of the program, ie a shutdown of the system.

Was in the program step 68 However, the operational readiness of at least one fuel cell module is detected, is in the program step 70 the current specification for the individual fuel cell mo dule set to I = 0.9 · I _Mot / n, ie the one already mentioned above in connection with the program step 18 from Table I, 90% of the engine power corresponding current.

Was in contrast to the initial program step 40 denies that the battery is fully charged, so in the next program step 42 asked whether the battery temperature exceeds the upper limit HI-HI, ie in the illustrated embodiment, whether the battery temperature is higher than 60 ° C.

If this is the case, it is done in the program step 54 a shutdown of the battery.

Otherwise, in the next program step 44 asked whether the battery temperature is higher than the lower limit temperature of the battery, that is higher than 50 ° C in the illustrated embodiment.

If this is the case, then after a start-up delay (program step 48 ) in the program step 52 a start of the fuel cells.

Thereafter, in the program step 64 again asked the feedback of the fuel cell modules to their operational readiness.

For the (rare) case, that at least one of the fuel cell modules should not be ready, takes place in the program step 72 End of program with system shutdown.

Was in the program step 64 but the operational readiness of at least one fuel cell module reported back, so takes place in program step 78 with a ramp-up over a period of 2 minutes setting the current setting to I = 0.5 · P _bur / U _batt , ie to half the full load. This contributes to the program step 44 detected increased battery temperature bill.

Was in the program step 44 However, it has been determined that the battery temperature is also below the lower temperature limit, ie below 50 ° C, after a startup delay (program step 46 ) in program step 50 a start of the fuel cells.

In program step 66 then the status feedback of the fuel cells is queried again.

If at least the feedback of a fuel cell module is not present, the program step is carried out 72 End of program with system shutdown.

Was in the program step 66 however, determined that at least one fuel cell module is ready, so is in program step 62 the current input is set after a ramp-up over a period of 2 minutes to the value I = P _bur / U _batt , ie to the permissible full load value.

The program flows shown in Tables I and II are of course only two possible embodiments of suitable methods for controlling the fuel cell hybrid drive. Other suitable methods can also be found. Also, the program flows shown are limited only to the control of the fuel cell modules in terms of state of charge and temperature of the battery and current demand of the drive motor, but here are not the other requirements for the operation of the entire system taken into account, such as stock in the hydrogen tank 16 , Security queries and the like.

1

A fuel cell assembly

2

traction battery

3

first power converter

4

drive motor

5

second power converter

6

control and surveillance system

7

AC charger

8th

Backup battery

9

Backup battery

10

power converter

11

power converter

12

Battery Monitor

13

I-driving

14

display

15

Board power system

16

Hydrogen tank

17

common conductor rail

Claims (16)

Fuel cell hybrid drive, in particular for a watercraft, in particular as an auxiliary drive for a sailing watercraft, with a fuel cell arrangement ( 1 ), a traction battery ( 2 ), and at least one drive motor ( 4 ), wherein the fuel cell assembly ( 1 ), the drive battery ( 2 ) and the drive motor ( 4 ) via an electrical power converter arrangement ( 3 . 5 ) and an electronic control and monitoring system ( 6 ) for the operation of the fuel cell assembly ( 1 ), the drive motor ( 4 ) and the drive battery ( 2 ), characterized in that the control and monitoring system ( 6 ) for carrying out a first operating state of the fuel cell hybrid drive, in which when the drive battery is not fully charged ( 2 ) and optional current consumption of the Drive motor ( 4 ) an operation of the fuel cell assembly ( 1 ) with full load current set for charging the traction battery ( 2 ), and a second operating state in which, when the drive battery is fully charged ( 2 ) and existing current consumption of the drive motor ( 4 ) an operation of the fuel cell assembly ( 1 ) with according to the load requirement of the drive motor ( 4 ) set current specification, is provided. Fuel cell hybrid drive according to claim 1, characterized in that the control and monitoring system ( 6 ) for carrying out the first operating state with current setpoint of the fuel cell arrangement set at full load ( 1 ) until reaching a first limit temperature HI of the drive battery ( 2 ) and when the first limit temperature HI of the drive battery ( 2 ) until reaching a second limit temperature HI-HI, which is higher than the first limit temperature HI, with set to a reduced charging current current specification of the fuel cell assembly ( 1 ) is provided. Fuel cell hybrid drive according to claim 2, characterized in that the control and monitoring system ( 6 ) for stopping the charging process of the drive battery ( 2 ) is provided at the second limit temperature HI-HI is exceeded. Fuel cell hybrid drive according to claim 1, 2 or 3, characterized in that the control and monitoring system ( 6 ) for carrying out the second operating state with a lower than that of the load request of the drive motor ( 4 ) corresponding value set current specification for the fuel cell assembly ( 1 ) is provided. Fuel cell hybrid drive according to one of claims 1 to 4, characterized in that further comprises at least one backup battery ( 8th . 9 ) is provided for on-board and / or operating power supply, which via an electrical power converter arrangement ( 10 . 11 ) is rechargeable. Fuel cell hybrid drive according to one of claims 1 to 5, characterized in that further comprises a mains charger ( 7 ) is provided, with which the drive battery ( 2 ) and / or the backup battery ( 8th . 9 ) are chargeable via a shore connection. Fuel cell hybrid drive according to one of claims 1 to 6, characterized in that the drive battery ( 2 ) with a common busbar ( 17 ), to which the fuel cell arrangement ( 1 ) via a first power converter ( 3 ) and the drive motor ( 4 ) via a second power converter ( 5 ) are connected. Fuel cell hybrid drive according to claim 7 in conjunction with claim 5 or 6, characterized in that the buffer battery ( 8th . 9 ) via the power converter arrangement ( 10 . 11 ) or the mains charger ( 7 ) to the common busbar ( 17 ) Are completed. Method for operating a fuel cell hybrid drive, in particular for a watercraft, in particular as an auxiliary drive for a sailing watercraft, having a fuel cell arrangement ( 1 ), a drive battery ( 2 ) and at least one drive motor ( 4 ), wherein the fuel cell assembly ( 1 ), the drive battery ( 2 ) and the drive motor ( 4 ) via an electrical power converter arrangement ( 3 . 5 ) are coupled together, and wherein the operation of the fuel cell assembly ( 1 ), the drive motor ( 4 ) and the drive battery ( 2 ) by an electronic control and monitoring system ( 6 ) is controlled and monitored, characterized in that in a first operating state with not fully charged drive battery ( 2 ) and optionally existing current consumption of the drive motor ( 4 ) the fuel cell assembly ( 1 ) with full load current set for charging the traction battery ( 2 ) and that in a second operating state when the drive battery is fully charged ( 2 ) and existing current consumption of the drive motor ( 4 ) the fuel cell assembly ( 1 ) with according to the load requirement of the drive motor ( 4 ) set current consumption is operated. A method according to claim 9, characterized in that the first operating state with set to full load operation current specification of the fuel cell assembly ( 1 ) until reaching a first limit temperature HI of the drive battery ( 2 ) and when the first limit temperature HI of the drive battery ( 2 ) until reaching a second limit temperature HI-HI, which is higher than the first limit temperature HI, with set to a reduced charging current current specification of the fuel cell assembly ( 1 ) is carried out. Method according to claim 9 or 10, characterized in that the control and monitoring system ( 6 ) the charging process of the drive battery ( 2 ) breaks off when the second limit temperature HI-HI is exceeded. Method according to claim 9, 10 or 11, characterized in that the control and monitoring system ( 6 ) the second operating state with a lower than the load request of the drive motor ( 4 ) corresponding value set current specification for the fuel cell assembly ( 1 ). Method according to one of claims 9 to 12, characterized in that at least one provided for on-board and / or operating power supply backup battery ( 8th . 9 ) via an electrical power converter arrangement ( 10 . 11 ) is charged. Method according to one of claims 9 to 13, characterized in that the drive battery ( 2 ) and / or the backup battery ( 8th . 9 ) by means of a further provided network charger ( 7 ) is charged via a shore connection. Method according to one of claims 9 to 14, characterized in that the current output of the fuel cell assembly ( 1 ) via a first power converter ( 3 ) and the current consumption of the drive motor ( 4 ) via a second power converter ( 5 ), via which the fuel cell arrangement ( 1 ) and the drive motor ( 4 ) to a common busbar ( 17 ), with which the drive battery ( 2 ) connected is. Method according to Claim 15 in conjunction with Claim 13 or 14, characterized in that the current consumption of the buffer battery ( 8th . 9 ) via the power converter arrangement ( 10 . 11 ) from the common busbar ( 17 ) or the current output of the network charger ( 7 ) to the common busbar ( 17 ) he follows.