System and method for controlling power of a fuel cell vehicle

Abstract

The present invention provides a system and method for controlling power in a fuel cell vehicle. The system includes a fuel cell, a battery, a sensor, and a controller. The fuel cell generates electricity by receiving fuel and an oxidizing gas. The battery receives the fuel cell's electrical energy to charge the battery or discharge the battery to provide electrical energy. The sensor senses the vehicle's driving state. The controller controls the charging or discharging of the battery based on the driving state sensed by the sensor.

Description

Technical Field

[0001] The present invention relates to a system and method for controlling electric power in a vehicle having a fuel cell, and more particularly to a strategy for charging and discharging a high-voltage battery according to the grade of a road on which the vehicle is traveling. Background Art

[0002] A fuel cell is a power generation device that converts chemical energy generated by the oxidation of a fuel directly into electrical energy. Fuel cells are similar to chemical batteries in that they utilize a redox reaction. However, unlike chemical batteries, which operate within a closed system, fuel cells continuously supply reactants and remove reaction products from the system. In recent years, fuel cell power generation systems have entered practical use, and because the reaction product of fuel cells is pure water, they are being actively researched for use as an energy source for environmentally friendly vehicles.

[0003] The fuel cell system includes a fuel cell stack, an air supply device, and a hydrogen supply device. The fuel cell stack generates electricity through chemical reactions. The air supply device supplies air to the cathode of the fuel cell stack, and the hydrogen supply device supplies hydrogen to the anode of the fuel cell stack. In other words, oxygen-containing air is supplied to the cathode of the fuel cell stack, while hydrogen is supplied to the anode of the fuel cell stack.

[0004] The fuel cell system also includes a high-voltage battery that stores the electricity generated by the fuel cell stack. The high-voltage battery is charged by the electricity generated by the fuel cell stack and the energy recovered by the drive motor, and provides electricity to assist the fuel cell stack during discharge.

[0005] When power generation is not required, the fuel cell stack enters Fuel Cell (FC) Stop Mode, where it stops generating electricity. In FC Stop Mode, air supply to the fuel cell stack is blocked. In particular, situations where the fuel cell stack is not required to generate power include: parking; driving using the discharged energy of the high-voltage battery; and recovering regenerative braking energy during downhill driving or deceleration.

[0006] In other words, in order to fully assist the power of the fuel cell stack and maximally maintain the FC stop mode of stopping power generation to ensure the durability of the fuel cell stack, the maximum rechargeable capacity of the high-voltage battery of the fuel cell vehicle should be increased, but the weight and cost also increase accordingly.

[0007] The above background technology is only used to enhance the understanding of the background of the present invention and should not be considered by those skilled in the art to correspond to conventional technology. Summary of the Invention

[0008] The present invention provides a technology for efficiently using a battery by sensing a driving state of a vehicle and adjusting the state of charge of the battery according to the driving state of the vehicle.

[0009] One aspect of the present invention provides a system for controlling the power of a vehicle having a fuel cell, the system may include a fuel cell, a battery, a sensor and a controller, the fuel cell being configured to generate electrical energy by receiving fuel and an oxidizing gas; the battery being configured to receive electrical energy from the fuel cell to charge the battery, or to discharge the battery to provide electrical energy; the sensor being configured to sense the driving state of the vehicle; and the controller being configured to adjust the charging or discharging of the battery based on the driving state sensed by the sensor.

[0010] The sensor may be configured to sense the slope of a road on which the vehicle is traveling or the inclination of the vehicle. The sensor may be configured to sense that the vehicle is traveling uphill when the slope of the road or the inclination of the vehicle is equal to or greater than a predetermined first reference value. Alternatively, the sensor may be configured to sense that the vehicle is traveling downhill when the slope of the road or the inclination of the vehicle is equal to or less than a predetermined second reference value.

[0011] The sensor may be configured to sense that the vehicle is traveling uphill when the slope of the road or the inclination of the vehicle remains equal to or greater than a predetermined first reference value for a predetermined reference time or longer. The sensor may be configured to sense that the vehicle is traveling downhill when the slope of the road or the inclination of the vehicle remains equal to or less than a predetermined second reference value for a predetermined reference time or longer. In addition, the sensor may be configured to sense the slope of the road on which the vehicle is traveling based on atmospheric pressure sensed by the vehicle, or to sense the inclination of the vehicle based on vehicle acceleration sensed by the vehicle.

[0012] The controller may be configured to set a target state of charge for the battery based on the sensed driving state and adjust charging or discharging of the battery to correspond to the set target state of charge. The controller may be configured to increase the target state of charge when the sensor determines that the vehicle is traveling uphill. The controller may be configured to decrease the target state of charge when the sensor determines that the vehicle is traveling downhill.

[0013] In addition, the controller may be configured to continuously increase or decrease the target state of charge if the sensor senses that the vehicle is traveling uphill or downhill. The controller may be configured to set the target state of charge to a predetermined state of charge when the sensor determines that the vehicle is traveling on flat ground. The controller may be configured to charge the battery when the current state of charge of the battery is less than the target state of charge, and to discharge the battery when the current state of charge of the battery exceeds the target state of charge. The controller may be configured to control the power generation of the fuel cell based on the state of charge of the battery to stop or continue.

[0014] Another aspect of the present invention provides a method for controlling power in a fuel cell vehicle, which may include: sensing a driving state of the vehicle; setting a target state of charge of a battery based on the sensed driving state; and charging or discharging the battery based on the set target state of charge.

[0015] Sensing the vehicle's driving state may include sensing the slope of a road on which the vehicle is traveling or the inclination of the vehicle. Setting the battery's target state of charge may include increasing the target state of charge in response to determining that the vehicle is traveling uphill. Setting the battery's target state of charge may include decreasing the target state of charge in response to determining that the vehicle is traveling downhill.

[0016] In addition, setting the target state of charge of the battery may include continuously increasing or decreasing the target state of charge when it is sensed that the vehicle is continuously traveling uphill or downhill. According to the system and method for controlling the power of a fuel cell vehicle of the present invention, the state of charge of the battery can be increased or decreased by charging or discharging the battery based on the driving state of the fuel cell vehicle, and the battery can be used efficiently. In other words, the battery can be used efficiently by increasing or decreasing the state of charge of the battery within the limited maximum state of charge of the battery as needed. In addition, by reducing the frequency of entering or releasing the fuel cell to stop power generation, fuel efficiency can be improved while improving the durability of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a block diagram illustrating a power control system of a fuel cell vehicle according to an exemplary embodiment of the present invention.

[0019] Figure 2 is a graph illustrating a target state of charge according to a duration of uphill traveling or downhill traveling according to an exemplary embodiment of the present invention.

[0020] Figure 3 is a graph illustrating a target state of charge during vehicle traveling according to an exemplary embodiment of the present invention.

[0021] Figure 4 is a flowchart illustrating a method for controlling electric power of a fuel cell vehicle according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0022] It should be understood that the term "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, ships including various boats, vessels, aircraft, etc., and include hybrid vehicles, electric vehicles, internal combustion engine vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from non-petroleum energy sources).

[0023] Although the exemplary embodiments are described as using multiple units to perform the exemplary processes, it should be understood that the exemplary processes can also be performed by one or more modules. Furthermore, it should be understood that the term controller / control unit refers to a hardware device that includes a memory and a processor and is specifically programmed to perform the processes described herein. The memory is configured to store the modules, and the processor is specifically configured to execute the modules to perform one or more processes described further below.

[0024] Unless otherwise stated or apparent from the context, the term "about" as used herein is understood to mean within the normal tolerance range in the art, for example, within 2 standard deviations of the mean. "About" can be understood to mean within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the specified value. Unless otherwise clear from the context, all numerical values ​​provided herein are modified by the term "about."

[0025] Furthermore, the control logic of the present invention can be implemented as non-volatile computer-readable media on a computer-readable medium, which includes executable program instructions executed by a processor, controller / control unit, etc. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable recording medium can also be distributed among network-connected computer systems so that the computer-readable media is stored and executed in a distributed manner, for example, via a telematics server or a controller area network (CAN).

[0026] The specific structural or functional descriptions of the exemplary embodiments of the present invention disclosed in this specification or application are merely for describing the exemplary embodiments of the present invention, and the exemplary embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the exemplary embodiments described in this specification or application.

[0027] Since the exemplary embodiments of the present invention can be modified in various ways and have various forms, specific exemplary embodiments will be shown in the drawings and described in detail in this specification or application. However, it should be understood that the exemplary embodiments according to the concepts of the present invention are not limited to the specific disclosed forms, but include all modified forms, equivalent forms or alternative forms that fall within the spirit and technical scope of the present invention.

[0028] It will be understood that although the terms "first," "second," etc. may be used herein to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the present invention.

[0029] When referring to an element being "coupled" or "connected" to another element, it should be understood that the element can be directly coupled or connected to the other element, or another element can be present between them. On the other hand, when referring to an element being "directly coupled" or "directly connected" to another element, it should be understood that another element does not exist between them. Other expressions describing the relationship between elements, namely, "between" and "directly between" or "adjacent" and "directly adjacent" should also be interpreted in the same manner.

[0030] The terms used in this specification are intended only to describe specific exemplary embodiments and are not intended to limit the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise," "include," and "comprising" are used to indicate the presence of the described features, quantities, steps, operations, elements, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, steps, operations, elements, parts, or combinations thereof.

[0031] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning within the scope of the relevant technology and should not be interpreted as an ideal meaning or an overly formal meaning unless clearly defined in this specification.

[0032] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each of the drawings, the same reference numerals represent the same elements.

[0033] Figure 1 1 is a block diagram showing a power control system of a vehicle having a fuel cell 10 according to an exemplary embodiment of the present invention. Figure 1 According to an exemplary embodiment of the present invention, a system for controlling electric power of a vehicle having a fuel cell 10 may include: a fuel cell 10, a battery 20, a sensor 50 and a controller 60, wherein the fuel cell 10 receives fuel and oxidizing gas and generates electric energy, the battery 20 receives the electric energy of the fuel cell 10 to be charged, or discharges to provide electric energy, the sensor 50 is configured to sense a driving state of the vehicle, and the controller 60 is configured to adjust the charging or discharging of the battery 20 based on the driving state sensed by the sensor 50.

[0034] The sensor 50 and the controller 60 according to the exemplary embodiment of the present invention can be implemented by a non-volatile memory (not shown) and a processor (not shown), wherein the non-volatile memory is configured to store data related to the following: an algorithm configured to control the operation of various components of the vehicle or software instructions for reproducing the algorithm, and the processor is configured to use the data stored in the memory to perform the operations described below. In particular, the memory and the processor can be implemented in the form of separate chips. Alternatively, the memory and the processor can be implemented in the form of a single chip integrated with each other. The processor can adopt one or more types of processors.

[0035] The fuel cell 10 may be a fuel cell stack 10 that receives hydrogen and oxygen-containing air as fuel through an anode and a cathode, respectively, and generates electricity through chemical reactions. Specifically, the fuel cell 10 may have a plurality of unit cells stacked therein, wherein fuel and air are introduced into each unit cell to generate electricity, and the fuel cell 10 may output high-voltage electricity through the unit cells connected in series.

[0036] The battery 20 may be electrically connected to the fuel cell 10, the drive device 30, and the auxiliary machine 40. As an exemplary embodiment, the fuel cell 10 may be connected in series to the drive device 30 and the auxiliary machine 40 via a main bus terminal, and the battery 20 may be connected in parallel to the main bus terminal. The battery 20 may be connected to the fuel cell 10 via a converter 21 interposed therebetween, and the converter 21 may be a bidirectional high-voltage direct current / direct current (DC / DC) converter (BHDC) configured to convert power in either a direction for charging the battery 20 or a direction for discharging the battery 20.

[0037] The controller 60 may be configured to operate the high-voltage converter 21 to control the charging or discharging of the battery 20. Specifically, the controller 60 may be a battery management system (BMS) configured to regulate the charging or discharging of the battery 20. The sensor 50 may be configured to sense the driving state of the fuel cell 10 vehicle. Specifically, the sensor 50 may be configured to sense whether the vehicle having the fuel cell 10 is driving on flat ground, driving uphill, or driving downhill, as described below.

[0038] In another exemplary embodiment, the sensor 50 may be configured to sense the vehicle having the fuel cell 10 being stopped, traveling at a low speed, traveling at a high speed, or traveling in a turn. The controller 60 may be configured to adjust the charge or discharge of the battery 20 based on the driving state sensed by the sensor 50. In other words, the controller 60 may be configured to increase or decrease the state of charge (SOC) of the battery 20 and efficiently use the battery 20 by adjusting the charge or discharge of the battery 20 based on the driving state of the fuel cell 10 vehicle.

[0039] Therefore, according to the present application, the battery 20 can be efficiently used by increasing or decreasing the SOC of the battery 20 as needed within the limited maximum SOC of the battery 20. In particular, the sensor 50 can be configured to sense the slope of the road on which the vehicle is traveling or the inclination of the vehicle. In other words, the sensor 50 can be configured to determine the slope of the road to determine the driving state of the vehicle while grounded, and the sensor 50 can be configured to directly sense the inclination of the vehicle to determine the driving state of the vehicle.

[0040] As an exemplary embodiment, the sensor 50 may be configured to sense the slope of the road on which the vehicle is traveling based on the atmospheric pressure sensed by the vehicle. An atmospheric pressure sensor 51 configured to measure the atmospheric pressure outside the vehicle may be installed in the vehicle, and the sensor 50 may be configured to sense the height of the road on which the vehicle is traveling based on the atmospheric pressure sensed by the atmospheric pressure sensor 51, and may determine whether the vehicle is traveling uphill, downhill, or on flat ground by sensing a change in height.

[0041] In another exemplary embodiment, the sensor 50 can be configured to directly sense changes in atmospheric pressure sensed by the atmospheric pressure sensor 51, thereby determining whether the vehicle is traveling uphill, downhill, or on flat ground. As another exemplary embodiment, the sensor 50 can be configured to sense the vehicle's inclination based on vehicle acceleration sensed by the vehicle. The vehicle can include a G-sensor 52 configured to sense gravity acceleration or a gyroscopic sensor for sensing yaw, roll, and pitch. The sensor 50 can be configured to use the vehicle acceleration sensed by the G-sensor 52 or the gyroscopic sensor to determine the vehicle's inclination.

[0042] In another exemplary embodiment, global positioning system (GPS) information and navigation information can be used to sense the slope of the road on which the vehicle is traveling. In particular, the navigation information can be used to sense in advance the slope of the road on which the vehicle is about to travel. The sensor 50 can be configured to sense that the vehicle is traveling uphill when the slope of the road or the inclination of the vehicle is equal to or greater than a predetermined first reference value, and can be configured to sense that the vehicle is traveling downhill when the slope of the road or the inclination of the vehicle is equal to or less than a predetermined second reference value.

[0043] Uphill driving may refer to a vehicle traveling on an uphill road, while downhill driving may refer to a vehicle traveling on a downhill road. Specifically, a first reference value may be preset to a slope greater than 0, at which the driving force required for vehicle travel increases by a predetermined level, and a second reference value may be preset to a slope less than 0, at which the driving force required for vehicle travel decreases by a predetermined level. Furthermore, sensor 50 may be configured to sense that the vehicle is traveling uphill or downhill when the road slope or vehicle inclination is equal to or greater than a predetermined first reference value or equal to or less than a predetermined second reference value and is maintained for a predetermined reference time T1 or longer.

[0044] Specifically, the sensor 50 may be configured to sense that the vehicle is traveling uphill when the road slope or the vehicle's inclination is equal to or greater than a predetermined first reference value and remains on the uphill road for a predetermined reference time T1 or longer. Alternatively, the sensor 50 may be configured to sense that the vehicle is traveling downhill when the road slope or the vehicle's inclination is equal to or less than a predetermined second reference value and remains on a downhill road for a predetermined reference time T1 or longer. Furthermore, the sensor 50 may be configured to sense that the vehicle is traveling on flat ground when the road slope or the vehicle's inclination is less than the predetermined first reference value and greater than the predetermined second reference value.

[0045] Figure 2 is a diagram showing a target state of charge according to a duration of uphill driving or downhill driving according to an exemplary embodiment of the present invention, and Figure 3 is a diagram showing a target state of charge during vehicle travel according to an exemplary embodiment of the present invention. Figure 2 and Figure 3 , the controller 60 may be configured to set a target state of charge of the battery 20 based on the sensed driving state, and adjust charging or discharging of the battery 20 to correspond to the set target state of charge.

[0046] According to the prior art, the target state of charge of the battery 20 can be set to a predetermined state of charge based on the performance of the battery 20. According to the present application, the controller 60 can be configured to set the target state of charge of the battery 20 based on the driving state sensed by the sensor 50. In addition, the controller 60 can be configured to adjust the charging or discharging of the battery 20 to correspond to the target state of charge. In particular, the controller 60 can be configured to operate the battery 20 to charge when the current state of charge of the battery 20 is less than the target state of charge, and to operate the battery 20 to discharge when the current state of charge of the battery 20 is greater than the target state of charge.

[0047] Specifically, the controller 60 may be configured to charge the battery 20 using the electric energy generated by the fuel cell 10, or to charge the battery 20 using the electric energy recovered from the drive device 30 or the auxiliary machine 40 through regenerative braking. Alternatively, the controller 60 may be configured to discharge the battery 20 by driving the drive device 30 or the auxiliary machine 40, thereby reducing the electric power generated by the fuel cell 10. The controller 60 may be configured to increase the target state of charge when the sensor 50 determines that the vehicle is traveling uphill.

[0048] In particular, the controller 60 may be configured to increase the target state of charge to a state greater than the previous state in response to determining that the vehicle is traveling uphill. As an exemplary embodiment, an increased state of charge that is greater than a predetermined state of charge may be set as the target state of charge in response to determining that the vehicle is traveling uphill. The controller 60 may be configured to decrease the target state of charge when the sensor 50 determines that the vehicle is traveling downhill. As an exemplary embodiment, a decreased state of charge that is less than a predetermined state of charge may be set as the target state of charge in response to determining that the vehicle is traveling downhill. The controller 60 may be configured to continuously increase or decrease the target state of charge if the sensor 50 senses that the vehicle is traveling uphill or downhill, if the sensor 50 senses that the vehicle is continuing to travel uphill or downhill.

[0049] like Figure 2 As shown, the sensor 50 can be configured to sense uphill driving or downhill driving when the slope of the road or the inclination of the vehicle is maintained on such a road for a predetermined reference time T1 or longer, and the controller 60 can be configured to increase or decrease the target state of charge. In addition, in a state where the sensor 50 senses that the vehicle is traveling uphill or downhill, when the sensor 50 senses that the slope of the road or the inclination of the vehicle is maintained for a predetermined reference time T1 or longer, the controller 60 can be configured to continuously increase or decrease the target state of charge.

[0050] In particular, the controller 60 may be configured to continuously increase or decrease the target state of charge, or to increase or decrease the target state of charge in predetermined steps. However, the controller 60 may be configured to set the target state of charge to be less than or equal to a predetermined maximum state of charge (H / W maximum state of charge) and greater than or equal to a predetermined minimum state of charge (H / W maximum state of discharge).

[0051] In an exemplary embodiment, the controller 60 may be configured to set the target state of charge to a predetermined state of charge when the sensor 50 determines that the vehicle is traveling on flat ground. In other words, the controller 60 may be configured to restore the target state of charge to a predetermined state of charge when the sensor 50 determines that the vehicle is traveling on flat ground. In particular, referring to Figure 3 , the controller 60 may be configured to first set the target state of charge to a predetermined state of charge.

[0052] The controller 60 may be configured to increase (+α) the target state of charge (①) when an uphill driving condition is satisfied (e.g., the slope of the road or the inclination of the vehicle is equal to or greater than a predetermined first reference value and is maintained for a predetermined reference time T1 or longer). The controller 60 may be configured to further increase (+β) the target state of charge (②) when the sensor 50 senses that the vehicle is traveling uphill and the uphill driving condition is satisfied again (e.g., the slope of the road or the inclination of the vehicle is equal to or greater than a predetermined first reference value and is maintained for a predetermined reference time T1 or longer).

[0053] The controller 60 may be configured to maintain the target state of charge without further increasing it (③) even if the vehicle continues to travel uphill at a predetermined first reference value or greater, when the vehicle does not continue to travel uphill for a predetermined reference time T1 or longer. The controller 60 may be configured to reduce (-β) the target state of charge (④) when a downhill travel condition is satisfied (e.g., the slope of the road or the inclination of the vehicle is equal to or less than a predetermined second reference value and is maintained for a predetermined reference time T1 or longer).

[0054] The controller 60 may be configured to maintain the target state of charge without further decreasing it when the sensor 50 senses that the vehicle is traveling downhill, even if the vehicle continues traveling downhill at a predetermined second reference value or less, if the vehicle does not continue traveling downhill for a predetermined reference time T1 or longer (⑤). The controller 60 may be configured to maintain the target state of charge without further increasing it when the vehicle does not continue traveling uphill for a predetermined reference time T1 or longer, even if the vehicle continues traveling uphill at a predetermined first reference value or more, if the vehicle does not continue traveling uphill for a predetermined reference time T1 or longer, in the downhill traveling state (⑥).

[0055] In addition, the controller 60 may be configured to maintain the target state of charge without further reduction (⑦) when the vehicle does not continue downhill driving for a predetermined reference time T1 or longer, even if the vehicle continues downhill driving at a predetermined second reference value or less in the downhill driving state. When the sensor 50 senses that the vehicle is traveling on flat ground, the controller 60 may be configured to restore the target state of charge to the predetermined state of charge (⑧).

[0056] Furthermore, the controller 60 can be configured to control the power generation of the fuel cell 10 to stop or continue the power generation based on the state of charge of the battery 20. Specifically, the controller 60 can be configured to control the power generation of the fuel cell 10 based on whether the state of charge of the battery 20 is equal to or greater than a target state of charge or less than a target state of charge. Furthermore, the controller 60 can be configured to control the power generation of the fuel cell 10 based on the power required by the drive device 30 and the auxiliary machinery 40.

[0057] In an exemplary embodiment, the controller 60 may be configured to stop power generation by the fuel cell 10 (e.g., FC stop mode) when the state of charge of the battery 20 is equal to or greater than the target state of charge and the power required by the drive device 30 and the auxiliary machinery 40 is equal to or less than a predetermined power. Alternatively, the controller 60 may be configured to resume power generation by the fuel cell 10 when the state of charge of the battery 20 is less than the target state of charge or the power required by the drive device 30 and the auxiliary machinery 40 is equal to or greater than a predetermined power.

[0058] Therefore, the controller 60 can be configured to increase the target state of charge to reduce the FC stop mode of the fuel cell 10, thereby continuously maintaining power generation. In particular, when the vehicle is traveling uphill, the drive device 30 may require more power than the fuel cell 10 can generate. Accordingly, power generation by the fuel cell 10 can be continued without unnecessarily stopping power generation by the fuel cell 10.

[0059] Furthermore, the controller 60 can be configured to increase the number of times the fuel cell 10 stops generating electricity by reducing the target state of charge. Specifically, when the vehicle is traveling downhill, the power required by the drive device 30 can be reduced and the amount of energy recovered through regenerative braking can be increased, thereby improving the durability of the fuel cell 10 and enhancing fuel efficiency. This is achieved by rapidly stopping power generation from the fuel cell 10 to maintain the FC stop mode. In other words, according to the present invention, the frequency of entering and exiting the fuel cell 10 power stop mode can be reduced, thereby improving the durability of the fuel cell 10 and enhancing fuel efficiency.

[0060] Figure 4 1 is a flowchart illustrating a method for controlling vehicle power of a fuel cell 10 according to an exemplary embodiment of the present invention. The method described below may be executed by a controller. Figure 4 , a method for controlling vehicle power of a fuel cell 10 according to an exemplary embodiment of the present invention may include: sensing a driving state of the vehicle (step S100); setting a target state of charge of the battery 20 based on the sensed driving state (step S200); and controlling charging or discharging of the battery 20 based on the set target state of charge (step S300).

[0061] In step S100 of sensing the driving state of the vehicle, the inclination of the vehicle or the slope of the road on which the vehicle is traveling may be sensed. In step S200 of setting the target state of charge of the battery 20, in response to determining that the driving state of the vehicle is uphill driving (S110), the target state of charge may be increased (step S210). In step S200 of setting the target state of charge of the battery 20, in response to determining that the driving state of the vehicle is downhill driving (S120), the target state of charge may be decreased (step S220).

[0062] In step S200 of setting the target state of charge of the battery 20, in response to determining that the driving state of the vehicle is level ground driving (S130), the target state of charge may be set to a predetermined state of charge (step S230). In step S200 of setting the target state of charge of the battery 20, if it is sensed that the vehicle is driving uphill (S110) or downhill (S120), if it is sensed that the vehicle continues to drive uphill (S110) or downhill (S120), the target state of charge may be continuously increased or decreased (steps S210 and S220).

[0063] Although one or more exemplary embodiments have been described with reference to the drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A system for controlling electric power in a vehicle having a fuel cell, comprising: a fuel cell configured to generate electrical energy by receiving a fuel and an oxidizing gas; a battery configured to receive the electrical energy from the fuel cell to charge the battery, or to discharge the battery to provide electrical energy; a sensor configured to sense a driving state of the vehicle; as well as a controller configured to control charging or discharging of the battery based on a driving state sensed by the sensor; In which, the controller is configured to increase the target power state in response to the sensor determining that the vehicle is traveling uphill, and to decrease the target power state in response to the sensor determining that the vehicle is traveling downhill; the controller is configured to continuously increase or decrease the target power state in a step-by-step manner when the sensor senses that the slope of the road or the inclination of the vehicle is maintained for a predetermined reference time or longer when the sensor senses that the vehicle is traveling uphill or downhill.

2. The system for controlling electric power of a fuel cell vehicle according to claim 1, wherein: The sensor is configured to sense the slope of a road on which the vehicle is traveling or the inclination of the vehicle.

3. The system for controlling electric power of a fuel cell vehicle according to claim 2, wherein: The sensor is configured to sense that the vehicle is traveling uphill when the slope of the road or the inclination of the vehicle is equal to or greater than a predetermined first reference value, and The sensor is configured to sense that the vehicle is traveling downhill when the slope of the road or the inclination of the vehicle is equal to or less than a predetermined second reference value.

4. The system for controlling electric power of a fuel cell vehicle according to claim 3, wherein: The sensor is configured to sense that the vehicle is traveling uphill when the slope of the road or the inclination of the vehicle remains equal to or greater than a predetermined first reference value for a predetermined reference time or longer, and The sensor is configured to sense that the vehicle is traveling downhill when the gradient of the road or the inclination of the vehicle remains equal to or less than a predetermined second reference value for a predetermined reference time or longer.

5. The system for controlling electric power of a fuel cell vehicle according to claim 2, wherein: The sensor is configured to sense a slope of a road on which the vehicle is traveling based on atmospheric pressure sensed by the vehicle, or to sense an inclination of the vehicle based on vehicle acceleration sensed by the vehicle.

6. The system for controlling electric power of a fuel cell vehicle according to claim 1, wherein: The controller is configured to set a target state of charge of the battery based on the sensed driving state, and control charging or discharging of the battery to correspond to the set target state of charge.

7. The system for controlling electric power of a fuel cell vehicle according to claim 6, wherein: The controller is configured to set the target state of charge to a predetermined state of charge in response to the sensor determining that the vehicle is traveling on level ground.

8. The system for controlling electric power of a fuel cell vehicle according to claim 6, wherein: The controller is configured to charge the battery in response to determining that the current state of charge of the battery is less than a target state of charge, and to discharge the battery in response to determining that the current state of charge of the battery exceeds the target state of charge.

9. The system for controlling electric power of a fuel cell vehicle according to claim 1, wherein: The controller is configured to control the power generation of the fuel cell to stop or continue the power generation based on the state of charge of the battery.

10. A method for controlling power in a vehicle having a fuel cell, comprising: sensing the driving state of the vehicle through a controller; setting, by a controller, a target state of charge of the battery based on the sensed driving state; Controlling the charging or discharging of the battery based on a set target state of charge through a controller; The target state of charge of the battery is set as follows: In response to determining that the vehicle is traveling uphill, increasing the target state of charge; in response to determining that the vehicle is traveling downhill, decreasing the target state of charge; In a state where it is sensed that the vehicle is traveling uphill or downhill, when it is sensed that the slope of the road or the inclination of the vehicle is maintained for a predetermined reference time or longer, the target state of charge is continuously increased or decreased in a step-by-step manner.

11. The method according to claim 10, wherein: Sensing the vehicle's driving status includes: The gradient of the road on which the vehicle is traveling or the inclination of the vehicle is sensed by the controller.

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