Method for operating a hydrogen fuel cell system in a vehicle and hydrogen fuel cell system for operating in said vehicle

Abstract

A method for operating a hydrogen fuel cell system in a vehicle, wherein the vehicle includes a vehicle control unit VCU, the vehicle control unit VCU is used to control the power supplied to the vehicle's transmission system from any one of a battery management system BMS and the hydrogen fuel cell system, the battery management system BMS includes at least one battery, and the hydrogen fuel cell system includes a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system further includes a fuel cell control unit FCCU and a direct current (DC) to DC converter, the method comprising the steps of: receiving an indication of a state of charge of the at least one battery; determining a demand for power to be supplied by the plurality of hydrogen fuel cells based on the indication of the state of charge of the at least one battery and based on an instantaneously requested amount of power; requesting the demand for power to be supplied by the plurality of hydrogen fuel cells; requiring an amount of current to be supplied by the plurality of hydrogen fuel cells, and supplying the required amount of current.

Description

Technical Field

[0001] The present disclosure relates to a method for operating a hydrogen fuel cell system in a vehicle. Background Art

[0002] A hydrogen fuel cell system according to the present disclosure includes a plurality of hydrogen fuel cells. Each of these fuel cells may include a fuel cell stack and a controller. A fuel cell stack is an electrochemical cell capable of converting chemical energy from hydrogen fuel and oxygen into electricity. The electricity may be used, for example, to drive an electric motor.

[0003] A hydrogen fuel cell stack is therefore different from a conventional battery. A fuel cell operates based on a fuel supplied to the fuel cell, ie in the form of hydrogen. In a battery, electricity is generated based on chemicals already present in the battery.

[0004] The present disclosure relates to the concept that in a vehicle, a hydrogen fuel cell system operates together with at least one battery. Whenever the vehicle needs electricity, for example due to the fact that the accelerator pedal is activated, the electricity can originate from the hydrogen fuel cell system and / or from the at least one battery.

[0005] One of the disadvantages of systems in which both a hydrogen fuel cell system and at least one battery are operated in a vehicle is related to the service life of the battery and / or the service life of the hydrogen fuel cell system. Summary of the invention

[0006] It is an object of the present disclosure to provide a method for operating a hydrogen fuel cell system in a vehicle.

[0007] The present disclosure provides in a first aspect a method for operating a hydrogen fuel cell system in a vehicle, wherein the vehicle includes a vehicle control unit VCU, and the vehicle control unit VCU is used to control the power supplied to the transmission system of the vehicle from any one of a battery management system BMS and the hydrogen fuel cell system, the battery management system BMS includes at least one battery, and the hydrogen fuel cell system includes a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system also includes a fuel cell control unit FCCU and a direct current (DC) to DC converter.

[0008] The method comprises the steps of:

[0009] receiving, by the FCCU from the VCU, an indication of a state of charge of the at least one battery;

[0010] determining, by the FCCU, a demand for electrical power to be provided by the plurality of hydrogen fuel cells based on the indication of the state of charge of the at least one battery and based on an instantaneously requested amount of electrical power;

[0011] requesting, by the FCCU, from the DC to DC converter, the demand for power to be provided by the plurality of hydrogen fuel cells;

[0012] requesting from the FCCU, by the DC to DC converter, an amount of current to be provided by the plurality of hydrogen fuel cells;

[0013] The required amount of current is supplied from the plurality of hydrogen fuel cells to the DC to DC converter by the FCCU.

[0014] The inventors have found that the VCU cannot control when the amount of power to be supplied by the hydrogen fuel cell system is required. The VCU is typically a physically separate function from the FCCC. The VCU may not know the characteristics of multiple hydrogen fuel cells. That is, the VCU may not understand how to efficiently pressurize the hydrogen fuel cell.

[0015] Therefore, the inventors have found a way for the FCCU to be responsible. The FCCU can determine to what extent multiple hydrogen fuel cells will be pressurized based on the state of charge of at least one battery. The FCCU can have a deep understanding of multiple hydrogen fuel cells, which the FCCU can use to determine to what extent the hydrogen fuel cells can be pressurized.

[0016] According to the present disclosure, the indication of the state of charge of at least one battery may be considered as information about how full the at least one battery actually is. Such information may be used by the FCCU to determine how much power may be consumed from the at least one battery. The inventors have noted that the useful life of a battery may be related to the state of charge maintained by the battery. Thus, for example, not completely depleting a battery may be advantageous, as completely depleting a battery may be detrimental to the useful life of the battery.

[0017] According to the above, the FCCU determines the demand for power to be provided by multiple hydrogen fuel cells based on an indication of the state of charge of at least one battery and based on the amount of power requested instantaneously. Here, the FCCU can consider power ramps that are beneficial to the service life of the hydrogen fuel cells, and can consider power ramps that are beneficial to the service life of at least one battery.

[0018] More specifically, the FCCU may follow a preferred power ramp curve for drawing power from multiple hydrogen fuel cells, and may entrust the VCU to draw the remaining power from at least one battery, i.e., the shortfall power as the difference between the instantaneously requested power amount and the power ramp curve.

[0019] According to the above, the DC to DC converter will request the amount of current to be provided by the plurality of hydrogen fuel cells based on the demand for power to be provided by the plurality of hydrogen fuel cells.

[0020] Note that according to the present disclosure, the DC to DC controller is controlled by the FCCU. For example, the FCCU can send a current request to the DC to DC converter via a bus (e.g., CANBUS). The DC to DC converter can then send back what amount of current flows through the DC to DC converter, for example, multiple times per second. This information can be used by the FCCU to control multiple fuel cells so that current can be maintained. As described above, one of the advantages of this is that the FCCU controls the amount of power to be provided by multiple hydrogen fuel cells.

[0021] The present application is therefore directed to the concept of the FCCU determining the amount of power to be provided by a plurality of hydrogen fuel cells based on, inter alia, the state of charge of at least one battery.

[0022] Another advantage of the present disclosure is that the FCCU is physically separated from the VCU. The FCCU is responsible for controlling the fuel cell. The VCU is responsible for controlling the vehicle. These two blocks operate independently of each other. This has the advantage that the FCCU can ensure that the fuel cell is safely stopped even when the VCU stops operating, or when the VCU experiences some error or the VCU experiences an error. Since the FCCU and the VCU are physically and operationally separated, the FCCU can ensure that the fuel cell is safely controlled.

[0023] This is true, for example, if there is a collision with a respective vehicle, a leak occurs in a fuel cell, a sensor begins to malfunction, and so on.

[0024] Further note that a DC to DC converter may be located between the plurality of hydrogen fuel cells and the vehicle (eg, at least one battery).

[0025] According to the present disclosure, the DC to DC converter may include a DC to DC converter controller that is responsible for controlling the operation of the DC to DC converter. The DC to DC converter controller may, for example, receive a demand for power and may send a demand for an amount of current, as described in the present disclosure.

[0026] According to the present disclosure, the instantaneous requested power can be defined as the total amount of power requested by the vehicle (more specifically, by the driver of the vehicle). The instantaneous requested power can be based on the vehicle's gas pedal, i.e., the accelerator. The instantaneous requested power can be communicated to the FCCU in several ways.

[0027] According to the present disclosure, the method includes the step of receiving, by the FCCU, an indication of the state of charge of the at least one battery from the VCU. This can be achieved in various ways. For example, the state of charge of the at least one battery can be calculated by a battery management system BMS and can be sent to the VCU via a bus (e.g., CANBUS). The VCU can then communicate the state of charge to the FCCU via a bus (e.g., CANBUS).

[0028] In the example, the determining step includes:

[0029] The FCCU determines a requirement for power to be provided by the plurality of hydrogen fuel cells so that the expected state of charge of the at least one battery does not fall below a predetermined threshold based on the indication of the state of charge of the at least one battery and based on the instantaneous requested amount of power.

[0030] An advantage of this particular example is that the service life of the at least one battery is ensured.

[0031] In a further example, the predetermined threshold is between 30%-55%, preferably between 45%-55%, and more preferably about 50%.

[0032] In an example, the method further comprises the steps of:

[0033] The FCCU receives fuel cell information from the plurality of hydrogen fuel cells, the fuel cell information including any of the following:

[0034] a voltage of each of the plurality of hydrogen fuel cells;

[0035] a voltage of the plurality of hydrogen fuel cells as a whole;

[0036] a relative voltage of the weakest cell compared to an average voltage of each of the plurality of hydrogen fuel cells;

[0037] Wherein, the determining step includes:

[0038] The demand for power to be provided by the plurality of hydrogen fuel cells is also determined by the FCCU based on the fuel cell information.

[0039] An advantage of this particular example is that the FCCU is able to operate multiple fuel cells in this way based on information which can directly influence the service life.

[0040] In another example, the FCCU includes a power-up curve and a power-down curve for indicating a preferred ramp-up curve for increasing power from the plurality of fuel cells and a preferred ramp-down curve for decreasing power from the plurality of fuel cells, respectively, and wherein the determining step includes:

[0041] The demand for electric power to be provided by the plurality of hydrogen fuel cells is determined by the FCCU further based on any of the power increase curve and the power decrease curve.

[0042] Preferably, the FCCU controls the amount of power to be provided by the plurality of hydrogen fuel cells so that the power actually delivered over time corresponds to the power increase curve. This ensures that the service life of the plurality of fuel cells is improved.

[0043] In a second aspect, a hydrogen fuel cell system for operating in a vehicle is provided, wherein the vehicle includes a vehicle control unit VCU, and the vehicle control unit VCU is used to control the power supplied to the transmission system of the vehicle from any one of a battery management system BMS and the hydrogen fuel cell system, the battery management system BMS includes at least one battery, and the hydrogen fuel cell system includes a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system also includes a fuel cell control unit FCCU and a direct current (DC) to DC converter.

[0044] The FCCU also includes:

[0045] a receiving device configured to receive an indication of a state of charge of the at least one battery from the VCU;

[0046] a processing device configured to determine a demand for electrical power to be provided by the plurality of hydrogen fuel cells based on the indication of the state of charge of the at least one battery and based on an instantaneously requested amount of electrical power;

[0047] a requesting device configured to request, from the DC-to-DC converter, the demand for electric power to be provided by the plurality of hydrogen fuel cells;

[0048] a demand device configured to demand from the FCCU an amount of current to be provided by the plurality of hydrogen fuel cells;

[0049] A supply device is configured to supply the required amount of current to the DC to DC converter.

[0050] Please note that the advantages and definitions disclosed with respect to the example of the first aspect of the present disclosure (which is a method for operating a hydrogen fuel cell system in a vehicle) also correspond to the example of the second aspect of the present disclosure (which is a hydrogen fuel cell system for operating in a vehicle).

[0051] In an example, the processing device is further configured to determine, based on the indication of the state of charge of the at least one battery and based on the instantaneously requested amount of power, a requirement for power to be provided by the plurality of hydrogen fuel cells so that an expected state of charge of the at least one battery does not fall below a predetermined threshold.

[0052] In another example, the predetermined threshold is 50%.

[0053] In another example, the receiving device is further configured to receive fuel cell information from the plurality of hydrogen fuel cells, the fuel cell information including any of the following:

[0054] a voltage of each of the plurality of hydrogen fuel cells;

[0055] a voltage of the plurality of hydrogen fuel cells as a whole;

[0056] a relative voltage of the weakest cell compared to an average voltage of each of the plurality of hydrogen fuel cells;

[0057] And wherein the processing device is further configured to determine the demand for power to be provided by the plurality of hydrogen fuel cells also based on the fuel cell information.

[0058] In another example, the FCCU includes a power-up curve and a power-down curve for indicating a preferred ramp-up curve for increasing power from the plurality of fuel cells and a preferred ramp-down curve for reducing power from the plurality of fuel cells, respectively, and wherein the processing device is further configured to determine the demand for power to be provided by the plurality of hydrogen fuel cells based also on any of the power-up curve and the power-down curve.

[0059] In a third aspect, a computer program product is provided, comprising a computer-readable medium having instructions stored thereon, which, when executed by a hydrogen fuel cell system, causes the hydrogen fuel cell system to implement a method according to any of the method examples provided above.

[0060] The above-mentioned features and advantages and other features and advantages of the present disclosure will be best understood from the following description with reference to the accompanying drawings.In the accompanying drawings, the same reference numerals represent the same components or components that perform the same or comparable functions or operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A schematic diagram illustrating the cooperation of a battery and a fuel cell system according to the present disclosure is schematically shown.

[0062] Figure 2A schematic diagram illustrating a hydrogen fuel cell system according to the present disclosure is schematically shown. DETAILED DESCRIPTION

[0063] Figure 1 Schematically showing the cooperation of the battery 3 and the fuel cell system according to the present disclosure Figure 1 .

[0064] The drive train of the vehicle is indicated by reference numeral 2. The drive train 2 of the vehicle is the collection of components that deliver electrical power to the drive wheels. This typically excludes the engine or electric motor that generates the electricity. In contrast, a powertrain is considered to include both the engine or electric motor and the drive train. In this particular scenario, the electricity originates from either a battery 3 or a hydrogen fuel cell, or a combination thereof.

[0065] The power delivered 12 to the drive train 2 is controlled by a vehicle control unit VCU 9. The VCU 9 draws 13 power from a battery 3 or is provided 14 with power originating from a hydrogen fuel cell.

[0066] The present disclosure relates to a method for operating a hydrogen fuel cell system in a vehicle. The fuel cell system comprises a fuel cell control unit FCCU 7, a direct current DC to DC converter 6 and a plurality of hydrogen fuel cells.

[0067] Hint Figure 1 3 represents a single functional block called battery 3. Please note that the present disclosure can deal with a battery management system BMS comprising at least one battery. Typically, a plurality of batteries can be provided for storing sufficient energy for driving the vehicle. The battery can be recharged by inductive electrical energy during braking of the vehicle.

[0068] The method may begin with the FCCU 7 receiving 11 an indication of the state of charge of the battery 3 from the VCU 9. The inventors have observed that in order to increase the useful life of a battery, the battery should ideally be operated within an operating window of between 40% and 65%.

[0069] According to the present disclosure, the FCCU 7 is separate from the VCU 9 and is responsible for distributing the requested power among the hydrogen fuel cells and the battery 3. To this end, the FCCU 7 may receive an indication of the state of charge of the battery 3 as described above.

[0070] The FCCU 7 may then determine the demand for electrical power to be provided by the plurality of hydrogen fuel cells based on the received indication of the state of charge and based on the amount of electrical power momentarily requested.

[0071] In other words, the FCCU 7 can determine, for example, how much power is to be provided by the plurality of hydrogen fuel cells so that the state of charge of the battery 3 may not drop below a certain threshold. This increases the service life of the plurality of fuel cells.

[0072] Next, the FCCU 7 may request 15 the demand for power to be provided by the plurality of hydrogen fuel cells from the DC to DC converter 6. The DC to DC converter then requests 16 from the FCCU 7 the amount of current to be provided by the plurality of hydrogen fuel cells, which is ultimately supplied 17 by the FCCU 7 to the DC to DC converter 6.

[0073] Please note that the current demand is indicated by reference numeral 4 , the current supply is indicated by reference numeral 8 , the state of charge is indicated by reference numeral 10 , and the fuel cell is indicated by reference numeral 5 .

[0074] Figure 2 A schematic diagram 51 illustrating a hydrogen fuel cell system according to the present disclosure is schematically shown.

[0075] The hydrogen fuel cell system 51 is configured to operate in a vehicle, wherein the vehicle includes a vehicle control unit VCU, and the vehicle control unit VCU is used to control the power supplied to the transmission system of the vehicle from any one of a battery management system BMS and the hydrogen fuel cell system, the battery management system BMS includes at least one battery, and the hydrogen fuel cell system includes a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system also includes a fuel cell control unit FCCU and a direct current DC to DC converter.

[0076] The FCCU also includes:

[0077] a receiving device 52 configured to receive an indication of a state of charge of the at least one battery from the VCU;

[0078] a processing device 53 configured to determine a demand for electrical power to be provided by said plurality of hydrogen fuel cells based on said indication of said state of charge of said at least one battery and based on an instantaneously requested amount of electrical power;

[0079] a request device 56 configured to request the demand for power to be provided by the plurality of hydrogen fuel cells from the DC to DC converter;

[0080] a demand device 54 configured to demand from the FCCU an amount of current to be provided by the plurality of hydrogen fuel cells;

[0081] The supply device 55 is configured to supply the required amount of current to the DC to DC converter.

[0082] Those skilled in the art will be able to understand and implement other variations of the disclosed examples when practicing the claimed disclosure according to the study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" does not exclude a plurality. A single processor or other unit may satisfy the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. The computer program may be stored / distributed on appropriate media such as optical storage media or solid-state media, etc., provided with or as part of other hardware, but may also be distributed in other forms (such as via the Internet or other wired or wireless telecommunications systems). Any reference numerals in the claims should not be considered to limit their scope.

[0083] The present disclosure is not limited to the examples disclosed above and can be modified and enhanced by those skilled in the art without having to apply inventive skills, beyond the protection scope of the present disclosure as disclosed in the appended claims.

Claims

1. A method for operating a hydrogen fuel cell system in a vehicle, wherein: The vehicle comprises a vehicle control unit VCU, the vehicle control unit VCU is used to control the power supplied to the drive train of the vehicle from any one of a battery management system BMS and a hydrogen fuel cell system, the battery management system BMS comprises at least one battery, and the hydrogen fuel cell system comprises a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system further comprises a fuel cell control unit FCCU and a direct current DC to DC converter, the FCCU is responsible for controlling the hydrogen fuel cell, the VCU is responsible for controlling the vehicle, and the FCCU and the VCU are physically and operationally separated so that the FCCU ensures that the hydrogen fuel cell is safely controlled, the method comprising the steps of: receiving, by the FCCU from the VCU, an indication of a state of charge of the at least one battery; determining, by the FCCU, a demand for electrical power to be provided by the plurality of hydrogen fuel cells based on the indication of the state of charge of the at least one battery and based on an instantaneously requested amount of electrical power; requesting, by the FCCU, from the DC to DC converter, the demand for power to be provided by the plurality of hydrogen fuel cells; requesting from the FCCU, by the DC to DC converter, an amount of current to be provided by the plurality of hydrogen fuel cells; The required amount of current is supplied from the plurality of hydrogen fuel cells to the DC to DC converter by the FCCU.

2. The method according to claim 1, wherein: The step of determining a demand for electrical power to be provided by the plurality of hydrogen fuel cells comprises: The FCCU determines a requirement for power to be provided by the plurality of hydrogen fuel cells so that an expected state of charge of the at least one battery does not fall below a predetermined threshold based on the indication of the state of charge of the at least one battery and based on the instantaneous requested amount of power.

3. The method according to claim 2, wherein: The predetermined threshold is 50%.

4. A method according to any preceding claim, wherein: The method further comprises the steps of: The FCCU receives fuel cell information from the plurality of hydrogen fuel cells, the fuel cell information including any of the following: a voltage of each of the plurality of hydrogen fuel cells; a voltage of the plurality of hydrogen fuel cells as a whole; a relative voltage of the weakest cell compared to an average voltage of each of the plurality of hydrogen fuel cells; Wherein, the determining step comprises: The demand for power to be provided by the plurality of hydrogen fuel cells is also determined by the FCCU based on the fuel cell information.

5. The method according to any one of claims 1 to 3, wherein: The FCCU includes a power-up curve and a power-down curve for indicating a preferred ramp-up curve for increasing power from the plurality of hydrogen fuel cells and a preferred ramp-down curve for decreasing power from the plurality of hydrogen fuel cells, respectively, and wherein the determining step includes: The demand for electric power to be provided by the plurality of hydrogen fuel cells is determined by the FCCU further based on any one of the electric power increase curve and the electric power decrease curve.

6. A hydrogen fuel cell system for operation in a vehicle, wherein: The vehicle comprises a vehicle control unit VCU for controlling power supplied to a powertrain of the vehicle from any one of a battery management system BMS and a hydrogen fuel cell system, the battery management system BMS comprising at least one battery, and the hydrogen fuel cell system comprising a plurality of hydrogen fuel cells, wherein the hydrogen fuel cell system further comprises a fuel cell control unit FCCU and a direct current DC to DC converter, the FCCU being responsible for controlling the hydrogen fuel cells, the VCU being responsible for controlling the vehicle, and the FCCU and the VCU being physically and operationally separate such that the FCCU ensures that the hydrogen fuel cells are safely controlled, the FCCU further comprising: a receiving device configured to receive an indication of a state of charge of the at least one battery from the VCU; a processing device configured to determine a demand for electrical power to be provided by the plurality of hydrogen fuel cells based on the indication of the state of charge of the at least one battery and based on an instantaneously requested amount of electrical power; a requesting device configured to request, from the DC-to-DC converter, the demand for electric power to be provided by the plurality of hydrogen fuel cells; a demand device configured to demand from the FCCU an amount of current to be provided by the plurality of hydrogen fuel cells; A supply device is configured to supply the required amount of current to the DC to DC converter.

7. The hydrogen fuel cell system according to claim 6, wherein: The processing device is further configured to determine, based on the indication of the state of charge of the at least one battery and based on the instantaneously requested amount of power, a requirement for power to be provided by the plurality of hydrogen fuel cells so that an expected state of charge of the at least one battery does not fall below a predetermined threshold.

8. The hydrogen fuel cell system according to claim 7, wherein: The predetermined threshold is 50%.

9. The hydrogen fuel cell system according to any one of claims 7-8, wherein: The receiving device is further configured to receive fuel cell information from the plurality of hydrogen fuel cells, the fuel cell information including any of the following: a voltage of each of the plurality of hydrogen fuel cells; a voltage of the plurality of hydrogen fuel cells as a whole; a relative voltage of the weakest cell compared to an average voltage of each of the plurality of hydrogen fuel cells; And wherein the processing device is further configured to determine the demand for power to be provided by the plurality of hydrogen fuel cells also based on the fuel cell information.

10. The hydrogen fuel cell system according to any one of claims 7-8, wherein: The FCCU includes a power increase curve and a power decrease curve, which are used to respectively indicate a preferred ramp-up curve for increasing the power from the multiple hydrogen fuel cells and a preferred ramp-down curve for reducing the power from the multiple hydrogen fuel cells, and wherein the processing device is further configured to determine the demand for power to be provided by the multiple hydrogen fuel cells based on any one of the power increase curve and the power decrease curve.

11. A computer program product comprising a computer readable medium having instructions stored thereon, which, when executed by a hydrogen fuel cell system, cause the hydrogen fuel cell system to implement the method according to any one of claims 1-5.

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