KR100673756B1 - Method for controlling operation of fuel cell hybrid system - Google Patents

Abstract

A method for controlling an operation of a fuel cell hybrid system is provided to prevent the fuel cell hybrid system from being unexpectedly shut down and to protect the battery by preventing a battery from being discharged below a critical capacity. A method for controlling an operation of a fuel cell hybrid system includes the steps of: sensing a discharge current of a battery(S10); extracting a limit voltage of the battery corresponding to the sensed discharge current(S14); sensing a voltage of the battery(S16); and comparing output power of the fuel cell hybrid system with required power of a load to control charge and discharge of the battery when the sensed voltage of the battery is lower than the limit voltage(S18). In the comparing step, the fuel cell hybrid system is stopped when the sensed voltage of the battery is lower than the limit voltage and the output of the fuel cell system is lower than the required power of the load, and an alarming signal for the stopping is outputted. In the comparing step, the battery is charged when the sensed voltage is lower than the limit voltage and the output power exceeds the required power of the load.

Description

{Method for controlling operation of fuel cell hybrid system}

1 is a flowchart illustrating an operation control method of a fuel cell hybrid system according to an exemplary embodiment of the present invention.

FIG. 2 is a graph illustrating a current (capacity) -voltage curve according to a discharge rate of a battery used in the driving control method of FIG. 1.

3 is a graph illustrating a current (capacity) -voltage curve according to the number of cycles of a battery used in the driving control method of FIG. 1.

4 is a block diagram illustrating an operation control apparatus of a fuel cell hybrid system according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating an example of a power distribution device coupled to an operation control device of the fuel cell hybrid system of FIG. 4.

FIG. 6 is a view schematically illustrating a fuel cell device of an operation control apparatus of the fuel cell hybrid system of FIG. 4.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell hybrid system, and more particularly, to a method and apparatus for controlling operation of a fuel cell hybrid system capable of preventing a battery from being discharged below a threshold capacity, preventing an unexpected shutdown of the system and protecting the battery. .

A fuel cell is a device that converts energy contained in a fuel into electrical energy directly by chemical reaction. For example, fuel cells generate electrical energy using a reaction in which water is generated from hydrogen and oxygen, that is, a combustion reaction of hydrogen. This is represented by the following reaction scheme.

2H ₂ + O _2- > 2H ₂ O + 1.23 V

Fuel cells include phosphoric acid type, molten carbonate type, solid oxide type, polymer electrolyte type and alkali type. Among them, the polymer electrolyte fuel cell refers to a fuel cell using a proton conductive polymer electrolyte membrane as an electrolyte. A polymer electrolyte fuel cell generally has a stack structure for high power, and includes a catalyst for smoothly reacting the positive electrode and the negative electrode in the stack. As the catalyst, a platinum catalyst supported on carbon is used. The fuel cell is drawing attention as a next-generation clean energy source with a very low emission of nitrogen compounds and sulfur oxides compared to a power generation system for burning fossil fuels.

On the other hand, the fuel cell system generates electric power of almost constant output by using sufficient fuel and air, and thus it is difficult to suddenly increase the output according to the change of the load. Therefore, when instantaneous high power is required at the load, it is difficult to increase the output power in the fuel cell system and thus it is not possible to respond to the load change quickly.

In order to solve the above problem, the conventional fuel cell system uses a fuel cell hybrid system in which a battery is coupled to supply the output of the battery to the load in response to the instantaneous high power demand of the load.

The battery has a smooth charging / discharging characteristic curve section and a voltage section whose capacity drops rapidly. If the battery consumes power below a sharp drop in capacity, the load on the laptop or mobile phone immediately shuts down, and the battery can be fatally damaged. Thus, the battery must be properly controlled so that its capacity is not used below a voltage that drops sharply.

SUMMARY OF THE INVENTION An object of the present invention is to control the operation of a fuel cell hybrid system capable of preventing the battery from being discharged below a threshold voltage at which the capacity of the battery begins to rapidly decrease, thereby preventing an unexpected shutdown of the system and protecting the battery and the fuel cell device. A method and apparatus are provided.

In order to achieve the above object, according to the first aspect of the present invention, in the operation control method of a fuel cell hybrid system for supplying at least one of the fuel cell device and the battery to the load, (a) in the operation control device Detecting a discharge current of the battery; (b) extracting a limit voltage of the battery corresponding to the detected discharge current; (c) sensing the voltage of the battery; And (d) controlling the charging and discharging of the battery by comparing the output power of the fuel cell device with the required power of the load when the sensed battery voltage is less than or equal to the threshold voltage. A method is provided.

Preferably, step (d) includes stopping the fuel cell hybrid system when the sensed battery voltage is below the threshold voltage and the output of the fuel cell device is below the required power of the load. In this case, the driving control method of the fuel cell hybrid system further includes outputting an alarm signal for stopping operation.

In addition, the step (d) includes the step of charging the battery when the detected battery voltage is less than the threshold voltage, the output power of the fuel cell device exceeds the required power of the load.

Also, in the step (d), when the battery voltage is less than the threshold voltage and the output of the fuel cell device is less than the required power of the load, separating the load from the fuel cell device, and charging the battery with the output power of the fuel cell device. It includes a step. In this case, the operation control method of the fuel cell hybrid system further includes outputting an alarm signal for disconnecting the load from the fuel cell device.

In addition, step (a) is a step of measuring the discharge current only when the battery is discharged.

In addition, the step (b), (b1) calculating the discharge rate of the battery from the discharge current; And (b2) extracting a threshold voltage corresponding to the discharge rate from a previously stored table.

In addition, the step (b1) further comprises the step of compensating for the discharge rate decrease by the cycle degradation of the battery.

According to a second aspect of the present invention, there is provided a fuel cell device that burns fuel to generate electrical energy, a rechargeable battery, and a power distribution device for supplying output power of at least one of the fuel cell device and the battery to a load. An operation control apparatus for a fuel cell hybrid system, comprising: a current detector for detecting a discharge current of a battery; A voltage detector detecting a voltage of the battery; Calculating a discharge rate from the discharge current, extracting a limit voltage of the battery corresponding to the calculated discharge rate from a pre-stored table, and comparing the battery voltage with the limit voltage; And a communication processor for generating a predetermined control signal or an alarm signal in response to an output signal of the arithmetic processing unit.

Preferably, the output signal of the computing unit is a signal for charging the battery when the battery voltage is below the threshold voltage and the output power of the fuel cell apparatus exceeds the required power of the load.

The output signal of the arithmetic processing unit may be configured to disconnect the load from the fuel cell device and charge the battery with the output power of the fuel cell device when the sensed battery voltage is less than the threshold voltage and the output of the fuel cell device is less than or equal to the required power of the load. It is a signal for.

In addition, the output signal of the arithmetic processing unit is a signal for stopping the fuel cell hybrid system when the sensed battery voltage is below the threshold voltage and the output of the fuel cell device is below the required power of the load.

The alarm signal is also an alarm signal for load disconnection or shutdown.

In addition, the operation control apparatus of the fuel cell hybrid system is coupled to the operation processing unit, and further includes a storage unit for storing the limit voltage corresponding to the discharge rate in the table.

In addition, the operation processing unit compensates for the discharge rate decrease due to the cycle deterioration of the battery, the storage unit stores the number of charge and discharge cycles of the battery.

In addition, the operation control apparatus of the fuel cell hybrid system further includes an analog-to-digital converter for converting signals of the current detector and the voltage detector, and for transferring the converted signal to the calculation processor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings for those skilled in the art to easily implement the present invention.

1 is a flowchart illustrating an operation control method of a fuel cell hybrid system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, in the operation control method of a fuel cell hybrid system, a limit voltage of a battery is changed and set according to a discharge rate of a battery in an operation control device to prevent an unexpected shutdown of the system when a high power demand of a load is required. As a result, the discharge of the battery is controlled to prevent the battery from being discharged below a voltage at which the capacity of the battery is sharply lowered.

Specifically, first, when the operation start signal is input to the fuel cell hybrid system (S10), the discharge current of the battery is sensed by the current detector (S12). For example, when the battery is discharged, the discharge current is detected through an ammeter, converted into a digital signal by an analog-to-digital converter, and the converted signal is sensed by an operation processor.

Next, the threshold voltage of the battery corresponding to the sensed discharge current is extracted (S14). This step is implemented to calculate the discharge rate by calculating the discharge current per unit time, and to extract the limit voltage of the battery corresponding to the discharge rate from the table pre-stored in the storage unit in the operation control device, or on the other hand the charge and discharge of the battery in the pre-stored table It can be implemented to extract the limit voltage of the battery corresponding to the number of cycles and the discharge current of the battery. The limit voltage corresponding to the discharge rate can be implemented as a function.

Next, in a state in which the limit voltage of the battery is prepared, the voltage of the battery is detected by the voltage detector (S16). For example, the battery voltage is detected through a voltmeter, converted into a digital signal by an analog-to-digital converter, and the converted signal is sensed by the computing processor.

Next, it is determined whether the detected battery voltage is lower than or equal to the threshold voltage (S18).

If the determination result is YES, it is determined whether the current stack output power exceeds the required power of the load (S20). If the determination result is no, the battery voltage is again sensed, and it is periodically determined whether the detected battery voltage is below the threshold voltage.

As a result of the determination, when the stack output power exceeds the required power of the load, the battery is charged while supplying the output power of the fuel cell device to the load (S22).

On the other hand, if the stack output power is less than or equal to the required power of the load, an alarm signal is output (S24). Here, the alarm signal may be either a signal for notifying load disconnection from the fuel cell device or a signal for notifying operation of the system according to a subsequent setting operation.

Next, the load is separated from the fuel cell device. Alternatively, the fuel cell hybrid system is stopped (S26). This step is for charging the battery first or after shutting down the system because it is difficult to meet the high power demand of the load in the state of low battery capacity. In this step, if the output power of the fuel cell device is greater than or equal to a predetermined value, the battery may be charged after disconnecting the load. If the output power of the fuel cell device is less than the predetermined value, the battery may be separately charged after stopping the system. According to the above-described configuration, it is possible to prevent damage to the battery or the system by failing to adequately meet the high power demand of the load when the capacity of the battery is insufficient.

FIG. 2 is a graph showing a current (capacity) -voltage curve according to a discharge rate of a battery employed in the driving control method of FIG. 1.

For the experiment, the battery was first prepared by charging for 3 hours at 0.5C-4.2V in a temperature atmosphere of 25 ℃. And in the same temperature atmosphere, the battery was discharged by discharge rate 0.2C, 0.5C, 1.0C, 1.5C, and 2.0C, respectively. Here, 1.0C indicates that the battery capacity can be discharged in one hour, and 0.2C indicates that the battery capacity can be discharged in five hours.

As can be seen in Figure 2, the voltage of the discharged battery is about 3.60V, about 3.50V, about 3.40V, about 3.30V and about when the discharge rate is 0.2C, 0.5C, 1.0C, 1.5C and 2.0C, respectively The capacity drops sharply from 3.20V. When power is consumed even under a sharp drop in capacity, the load on the laptop or cell phone is shut down immediately, and the battery has a fatal adverse effect. For example, if the system's cut-off voltage (hereinafter referred to as the limit voltage) of the battery is set at 3.6 V, it will work ideally when the discharge rate is 0.2C, but the capacity remains when the discharge rate is 2.0C. The system must be stopped to prevent unexpected shutdown of the system. Conversely, setting the threshold voltage to 3.25V is ideal when the discharge rate is 2.0C, but shuts down the system for discharge rates below that, which has a catastrophic effect on the battery and the system.

Therefore, in the present invention, by changing the threshold voltage of the battery in accordance with the change of the load, it is possible not only to control the battery and system stably and effectively, but also to utilize the battery stably.

3 is a graph illustrating a current (capacity) -voltage curve according to the number of cycles of a battery employed in the driving control method of FIG. 1.

For the experiment, the battery was first prepared by charging for 3 hours at 0.5C-4.2V in an atmosphere of 25 ℃. And the batteries were discharged 0, 50, 100, 500 times at 0.5C-4.2V in the same temperature atmosphere.

As can be seen in Figure 3, the voltage of the battery according to the number of discharges, 0, 50, 100, 500 times, the capacity sharply drops from about 3.35V, about 3.25V, about 3.20V and about 3.10V, respectively.

Accordingly, in the operation control method according to the present embodiment, the compensation value of the limit voltage corresponding to the number of cycles of the battery, or another limit voltage to which the compensation value is applied is additionally stored in the storage unit, and the battery is stored according to the number of cycles. It compensates for the increased discharge rate and dynamically controls the limit voltage of the battery with greater precision.

4 is a block diagram illustrating an operation control apparatus of a fuel cell hybrid system according to an exemplary embodiment of the present invention. In the following description, when an element is coupled to another element, the element is directly coupled to another element and is coupled to another element.

Referring to FIG. 4, the operation control apparatus 100 (hereinafter referred to as operation control apparatus) of the fuel cell hybrid system includes a voltage detector 110, a current detector 120, and three analog-to-digital converters 132, 134, and 136. (Hereinafter referred to as A / D converter), arithmetic processing unit 140, communication processing unit 150 and storage unit 160. In addition, the operation control device 100 is coupled to the battery 200, the fuel cell device 300, the power distribution device 400 and the electric device 500.

In detail, the voltage detector 110 detects a voltage of the battery 200. The voltage detector 110 may be configured to detect a voltage of the entire battery 200 or measure respective voltages of a plurality of battery cells in the battery 200. The voltage detector 110 provides the detected signal to the calculation processor 140 through the first A / D converter 132. The voltage detector 110 may be implemented with a conventional voltmeter.

The current detector 120 is connected in series to an anode electrode (cathode) of the battery 200 and detects a current discharged from the battery 200. The current detector 120 provides the detected signal to the operation processor 140 through the second A / D converter 134. The current detector 120 may be implemented with a conventional ammeter.

The operation processor 140 detects a signal input from the voltage detector 110 and the current detector 120, and processes the detected signal according to a predetermined processing routine. Here, the detected signal includes a discharge current and a battery voltage of the battery.

In detail, the operation processor 140 extracts a threshold voltage corresponding to the sensed discharge current from the table stored in the storage 160. On the other hand, the calculation unit 140 extracts a limit voltage corresponding to the number of cycles of the battery 200 and the detected discharge current from the table stored in the storage unit 160. In addition, the operation processor 140 detects the current and voltage applied to the input terminal of the fuel cell device 300 and the output terminal of the electric device 500 by the third A / D converter 136 of the power distribution device 400. do. This is for detecting the output power of the fuel cell device 300 and the required power of the electric device 500 as a load. In the above-described case, the power of the input terminal and the output terminal of the power distribution apparatus 400 may be detected by a predetermined current / voltage sensing means, and the current / voltage sensing means may be built in the power distribution apparatus 400 or may be configured separately. have.

In addition, the operation processor 140 compares the threshold voltage and the battery voltage, compares the output power of the fuel cell device 300 with the required power of the electric device 500, and then outputs a predetermined output signal according to the comparison result. Generate. The generated output signal is transmitted to the communication processor 150. The operation processor 140 may be implemented as a digital signal processing device, and in this case, one or more of the three A / D converters may be omitted.

The above-described output signal is a signal for charging the battery when the battery voltage is below the threshold voltage and the output power of the fuel cell apparatus exceeds the required power of the load. Alternatively, the above-described output signal may be used to disconnect the load from the fuel cell device and charge the battery with the output power of the fuel cell device when the detected battery voltage is less than the threshold voltage and the output of the fuel cell device is less than or equal to the required power of the load. It is a signal. Alternatively, the above-described output signal is a signal for stopping the fuel cell hybrid system when the sensed battery voltage is below the threshold voltage and the output of the fuel cell device is below the required power of the load.

The communication processor 150 generates a control signal in response to the output signal of the operation processor 140, and transmits the generated control signal to the power distribution device 400 and / or the electric device 500. In addition, the communication processor 150 generates an alarm signal in response to the output signal of the operation processor 140. The generated alarm signal is transmitted to an imaging device or an audio device coupled to the driving control device 100 or transmitted to the electric device 500 and output through a screen or a speaker of the electric device 500. The communication processor 150 may be implemented as a wired or wireless communication circuit including a wired or wireless interface.

The storage unit 160 may include a table storing the discharge current of the battery 200 and the limit voltage of the battery corresponding to the discharge current. In addition, the storage 160 may store the number of charge / discharge cycles, that is, the cycle number of the battery 200. The storage unit 160 is coupled to the operation processor 140 and may be implemented as any storage device such as a RAM, a ROM, a flash memory, a hard disk, or the like. In addition, the storage 160 may be implemented as a logic circuit implemented by AND, OR, NAND, NOR gate, or the like.

The battery 200 includes a rechargeable battery that can be recharged by the fuel cell device 300 or an external commercial power source. The battery 200 may be implemented with at least one lithium ion secondary battery.

When the battery 200 is composed of a plurality of lithium ion secondary batteries connected in series, each of the secondary batteries may react differently to the charging current when the battery 200 is charged. The voltage detector 110 capable of independently detecting the charging voltage may be combined. In this case, since the failure of a specific secondary battery in the battery 200 can be detected, there is an advantage that the state of the battery 200 can be more accurately identified.

The electric device 500 refers to an electrical load using electric energy of the battery 200 or the fuel cell device 300. The electric device 500 includes all devices that use electricity, such as a laptop, a mobile phone, and a home electric appliance. In addition, the electrical device 500 is coupled to the communication processing unit 150 of the operation control system 100, receives a control signal or an alarm signal of the communication processing unit 150, and in response to the signal to the warning signal to the screen or speaker It includes a device capable of outputting.

FIG. 5 is a diagram schematically illustrating an example of a power distribution device coupled to an operation control device of the fuel cell hybrid system of FIG. 4.

Referring to FIG. 5, the power distribution device 400 includes switching units 410 and 420, current / voltage detectors 432, 434, 436 and 438, and a power converter 440.

The switching units 410 and 420 are controlled by the operation processor and are coupled to supply electric power to at least one of a battery and a fuel cell device. The switching units 410 and 420 may be implemented as semiconductor switches, for example, transistors or thyristors.

The current / voltage detectors 432, 434, 436, and 438 are implemented with conventional voltmeters and ammeters. The current / voltage detector detects the output power of the fuel cell device, detects the required power of the electric device as a load, and transfers the detected signal to the calculation processing unit through the A / D converter.

The power converter 440 converts the output power of the fuel cell device to a level and / or a manner suitable for use in an electric device. The power converter 440 may be implemented as a DC / DC converter for converting the direct current of the fuel cell device to a different level of direct current or a DC / AC converter for converting the direct current of the fuel cell device to AC.

FIG. 6 is a view schematically illustrating a fuel cell device of an operation control apparatus of the fuel cell hybrid system of FIG. 4.

Referring to FIG. 6, the fuel cell apparatus 300 includes an electricity generator 310, a fuel tank 320, a fuel pump 330, a fuel reformer 340, and an oxidant supply device 350.

The fuel tank 320 stores hydrocarbon-based fuels such as methanol, ethanol, and natural gas. The fuel pump 330 supplies fuel stored in the fuel tank 320 to the anode of the electricity generator 310. The fuel reformer 340 reforms the fuel to supply reformed gas rich in hydrogen to the electricity generator 310. The fuel reformer 340 may be omitted when the electricity generating unit 310 is a direct methanol fuel cell method. The oxidant supply device 350 supplies an oxidant such as air or oxygen to the cathode of the electricity generator 310 and may be implemented as an air pump or a blower.

Referring to the above-described electricity generating unit 310 in more detail as follows. The electricity generating unit 310 may be implemented as a fuel cell stack in which a plurality of unit cells are stacked. The electricity generation unit 310 includes an electrolyte membrane 311 and a membrane-electrode assembly including an anode electrode 313 and a cathode electrode 315 bonded to both surfaces of the electrolyte membrane 311. The plurality of membrane-electrode assemblies are stacked with separators 317 and 319 or bipolar plates that independently supply fuel and oxidant to the anode electrode 313 and the cathode electrode 315.

The electrolyte membrane 311 has a function of ion exchange to transfer hydrogen ions generated from the anode electrode 313 to the cathode electrode 315 and has a barrier function to prevent permeation of fuel in the gas phase or liquid phase. The electrolyte membrane 311 is a polymer membrane and has a thickness of about 50 to 200 μm.

The above-described electrolyte membrane 311 is preferably selected from materials having appropriate properties such as high cationic conductivity, high resistance to electron conductivity, high barrier resistance to gas permeation, high chemical stability, mechanical strength, size stability, heat resistance, and the like. Do.

For example, a perfluorosulfonic acid ion exchange membrane, a hydrocarbon electrolyte membrane, or a fullerene electrolyte membrane is used as the electrolyte membrane 311. For example, as the electrolyte membrane 232, a PTEE woven fabric or a PTEE porous membrane is embedded in a perfluorocarbon sulfonic acid (PFSA) polymer membrane, or a membrane is formed by adding PTEE fibers to a PFSA polymer membrane, or polytetrafluoroethylene (Teflon). ) A Gore membrane filled with PFSA in the porous body or a platinum-polymer electrolyte membrane having high dispersion of platinum fine particles can be used.

The anode electrode 313 functions to obtain hydrogen ions from the fuel. The anode electrode 313 is a catalyst layer that oxidizes fuel to convert hydrogen ions and electrons, and a diffusion layer that delivers fuel supplied through the separators 317 and 319 to the catalyst layer relatively uniformly. It is provided. The diffusion layer of the anode electrode 313 is implemented by a carbon layer and a backing layer, the carbon layer is a layer coated with a microporous layer, and the backing layer is carbon cloth. cloth). In addition, the above-described carbon layer functions to uniformly distribute the fuel, excellent electron conduction to the catalyst layer, and maintain a predetermined amount of water in the catalyst layer, and the above-described backing layer easily discharges carbon dioxide while supplying a sufficient amount of fuel. Is provided with pores of the appropriate size.

The cathode electrode 315 functions to react hydrogen ions (proton) with oxygen to obtain heat and water. The cathode electrode 315 supplies a catalyst layer for reacting hydrogen ions moved through the electrolyte membrane 311 and electrons moved through an external electric wire with an oxidant, for example, oxygen in the air, and oxygen in the air to the catalyst layer relatively uniformly. And a diffusion layer for effectively discharging the water produced as a by-product. The diffusion layer of the cathode electrode 315 is fabricated substantially the same as the diffusion layer of the anode electrode 313.

On the other hand, as an electrode catalyst that can be used for the oxidation of fuel in a strongly acidic atmosphere in contact with the electrolyte membrane 311, platinum (Pt) is preferable from the viewpoint of the chemical stability and the viewpoint that the platinum group metal is strong and catalytically active. Therefore, as the electrode catalyst of the cathode electrode 315, a carbon supported platinum catalyst or an unsupported platinum black catalyst is suitable for use.

However, platinum used for the anode electrode 313 is severely poisoned and is not practical. In other words, the poisoning of platinum is because carbon monoxide (CO) or HCO (or COH) generated during the reaction of the fuel cell is strongly adsorbed on the surface of the platinum to block the active site, thereby degrading the catalytic activity. On the other hand, when metal elements such as tin (Sn), ruthenium (Ru), rhenium (Re), molybdenum (Mo), osmium (Os) and iridium (Ir) are added to platinum, the inertness of methanol oxidation is improved. It is known. Therefore, it is preferable to use a platinum-ruthenium (Pt-Ru) -based two-component catalyst as the electrode catalyst of the anode electrode 313 which is most advantageous among the metal elements. For example, a carbon-supported platinum-ruthenium catalyst or an unsupported platinum-ruthenium black catalyst is used as the electrode catalyst of the anode electrode 313. On the other hand, as the electrode catalyst of the anode electrode 313, a catalyst in which tungsten (W) or molybdenum (Mo) is added to platinum-ruthenium may be used to improve the activity of the platinum-ruthenium catalyst.

On the other hand, it is difficult to combine the two devices with each other because the profile of the output voltage of the fuel cell device and the profile of the discharge voltage of the battery are different. In addition, in order to combine the output voltage of the fuel cell device and the battery, an additional expensive control device is required, and a system equipped with such an expensive control device is complicated in construction. Therefore, in the above-described embodiment, a combination of the output voltages of the fuel cell device and the battery is omitted, and a configuration in which the load is performed by the battery only when the high power of the load is required is described as a preferred embodiment.

On the other hand, although not explicitly mentioned in the above-described embodiment, the step of detecting the discharge current and the voltage of the battery includes detecting either one of the discharge current and the voltage first or both at the same time. The current / voltage detector of the above-described embodiment can be installed at any position as long as it can directly or indirectly detect the discharge current and voltage of the battery.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to the present invention, it is possible to easily prevent the battery from discharging below the limit capacity in the fuel cell hybrid system, thereby preventing unexpected shutdown of the system and protecting the battery.

Claims (17)

In the operation control method of a fuel cell hybrid system for supplying power to at least one of the fuel cell device and the battery, (a) detecting a discharge current of the battery; (b) extracting a threshold voltage of the battery corresponding to the sensed discharge current; (c) sensing the voltage of the battery; And and controlling the charging and discharging of the battery by comparing the output power of the fuel cell device with the required power of the load when the sensed battery voltage is less than or equal to the threshold voltage. Way. The method of claim 1, The fuel cell hybrid may include stopping the fuel cell hybrid system when the sensed battery voltage is less than the threshold voltage and the output of the fuel cell device is less than or equal to the required power of the load. Operation control method of system. The method of claim 2, And outputting an alarm signal for stopping operation of the fuel cell hybrid system. The method of claim 1, The step (d) of the fuel cell hybrid system comprising the step of charging the battery when the sensed battery voltage is less than the threshold voltage, the output power of the fuel cell device exceeds the required power of the load Operation control method. The method of claim 1, In the step (d), when the sensed battery voltage is less than the threshold voltage and the output of the fuel cell device is less than or equal to the required power of the load, separating the load from the fuel cell device, and the fuel cell device And charging the battery with an output power of the fuel cell hybrid system. The method of claim 5, And outputting an alarm signal for disconnecting the load from the fuel cell device. The method of claim 1, Wherein (a) is a step of measuring the discharge current only when the battery discharge operation control method of a fuel cell hybrid system. The method according to any one of claims 1 to 7, In step (b), calculating a discharge rate of the battery from the discharge current; And (b2) extracting the threshold voltage corresponding to the discharge rate from a pre-stored table. The method of claim 8, The step (b1) further comprises the step of compensating for the discharge rate decrease by the cycle deterioration of the battery. delete delete delete delete delete delete delete delete

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