Method of controlling the measurement of cell voltage of fuel cell and device for carrying out the same

Abstract

Device for controlling a measurement of a cell voltage of a fuel cell, characterized in that the device comprises: a plurality of terminals (110_1 - 110_n) connected between cells of a fuel cell connected in series; first resistors (R1 - Rn), each connected in series to a plurality of terminals (110_1 - 110_n); a plurality of capacitors (C1 - Cn), all connected in parallel between the first resistors (R1 - Rn) and configured to store voltages; a plurality of switches (S1 - Sn) each connected to the first resistors (R1 - Rn) and configured to switch to a closed state or an open state, a second resistor (120) connected in series between the (-) terminal of the lowest cell of the cells of the fuel cell and a semiconductor ground, configured to provide a path along which a current flows when an inverse voltage is generated in the cells of the fuel cell; a diode (130) connected in parallel with the second resistor (120) and configured to provide a path along which a current flows when an inverse voltage is not generated in the cells of the fuel cell; and a controller (140) configured to change the state of each of the plurality of switches (S1 - Sn) depending on a cell voltage measurement mode or a wire breakage diagnosis mode, and to perform cell voltage measurement and wire breakage diagnosis.

Description

Cross-Reference to Related ApplicationBACKGROUND OF THE INVENTIONEmbodiments of the present disclosure relate to a method for controlling measurement of a cell voltage of a fuel cell and a device for executing the same, and more specifically, to a method for controlling measurement of a cell voltage of a fuel cell that can prevent firing of a fuel cell voltage measurement semiconductor that is recoverable to an inverse voltage by limiting a reverse current when the inverse voltage is generated in the fuel cell in such a manner that the reverse current is caused to flow through a resistance of the fuel cell voltage measurement semiconductor, not a pin, and a device for executing the same.In general, a fuel cell is a power conversion device for directly converting chemical energy from fuel into electric power by a chemical reaction.Unlike a general battery, a fuel cell is a generation system capable of continuously generating electricity as long as fuel is supplied without a need for charging.As illustrated in FIG. 1, such a fuel cell has a shape in which an electrolyte and two electrodes have been stacked as in a sandwich. When oxygen (O 2) and hydrogen (H 2) flow into the respective electrodes, electricity is generated and heat and water are generated as byproducts.In a reaction for generating electricity of the fuel cell, after hydrogen (H 2), supplied to an anode, that is, an oxidation pole of the fuel cell, is separated into hydrogen ions and electrons, the hydrogen ions move to a cathode, that is, a reduction pole through a polymer electrolyte film. The electrons travel through an external circuit to the cathode. Oxygen molecules, the hydrogen ions and the electrons react with each other at the cathode and generate electricity and heat. At the same time, water is produced as a reaction by-product.If an appropriate amount of water is present inside the fuel cell, water generated when an electrochemical reaction occurs preferably serves to maintain humidification of a film electrode bonding body.However, if water is not adequately removed when an excess amount of water is generated, a "water overflow or flooding" phenomenon occurs in a high current density. The overflowing water functions to prevent reaction gases from being efficiently supplied to a cell of the fuel cell, thereby further increasing a voltage loss.A supply depletion problem of both hydrogen at the anode, oxygen of the cathode, that is, reagent gases used for PEMPFC, or air may occur due to various causes such as water spill within a fuel cell, ice formation in winter, and abnormality of a reaction gas supply device.However, it has been known that a cell voltage is greatly reduced because the hydrogen fuel depletion of the anode has a very fatal effect on the cell performance of the fuel cell.In general, the depletion phenomenon can be fundamentally divided into a "total hydrogen depletion" phenomenon in which a hydrogen supply is generally depleted in a cell of a fuel cell and a "local hydrogen depletion" phenomenon in which a total hydrogen supply to a cell is sufficient but a hydrogen supply is partially depleted due to an uneven distribution.In particular, such a hydrogen depletion phenomenon frequently occurs in operating conditions such as uneven supply and distribution of hydrogen gas, sudden increase in fuel cell load demand, and fuel cell starts.Among them, the total hydrogen depletion phenomenon can be relatively easily detected by monitoring a hydrogen supply state using a sensor in a fuel cell operating device (i.e., trade-off), but a local hydrogen depletion phenomenon in some cells can be detected only by closely monitoring each cell of a fuel cell by a cell voltage measurement semiconductor.For example, a voltage of a cell may suddenly drop to 0.1 V while a fuel cell is normally operating for 5 minutes or more. If such sudden cell voltage drop phenomenon occurs, an abnormal operation cell needs to be replaced and repaired after the operation of the fuel cell inside a fuel cell vehicle is immediately stopped, and the fuel cell is disassembled for the continuous operation of the vehicle.Most such phenomena occur due to local hydrogen feed depletion. If a cell whose voltage suddenly drops remains and a vehicle continues to operate, a cell inverse voltage state in which a voltage reaches a voltage lower than 0 V is quickly reached. Accordingly, corrosion of carbon, i.e., a catalytic carrier of MEA, can be accelerated.As described above, when an inverse voltage is generated in a conventional fuel cell, a reverse current is applied to a cell voltage measurement semiconductor. There is a problem that the cell voltage measurement semiconductor may burn due to a low tolerance for an inverse voltage.Further, there is a need for a scheme for preventing erroneous operation because the erroneous operation occurs during a wire breakage diagnostic operation using the cell voltage measurement semiconductor.KR 10-2018-066337 A describes a battery cell monitoring device comprising: one or more terminals connected via a cable to one or more series-connected battery cells; first, second and third resistors connected in series with the one or more terminals; one or more first comparators measuring the current or voltage at both ends of the second resistor for each of the one or more terminals; one or more first switches connected in series between the second resistor and the third resistor for each of the one or more terminals; one or more second switches connected in parallel between the second resistor and the first switch for each of the one or more terminals; and a control unit monitoring the respective battery cells based on the output of the respective first comparators.BRIEF SUMMARYVarious embodiments are directed to providing a method for controlling measurement of a cell voltage of a fuel cell, which may prevent firing of a fuel cell voltage measurement semiconductor attributable to an inverse voltage by limiting a reverse continuous current in such a manner that a reverse current is caused to flow through a resistor having a higher resistance value than a separate cell voltage measurement circuit, not a resistor of a cell voltage measurement circuit when the inverse voltage is generated while a battery cell is operating in a cell voltage measurement mode, and a device for executing the same.Further, various embodiments are directed to providing a method for controlling measurement of a cell voltage of a fuel cell, which can prevent occurrence of a voltage drop attributable to a current flowing through a resistor in such a manner that the current is caused to flow through a diode when a battery cell is in a cell voltage measurement mode or a wire breakage diagnosis mode, and a device for executing the same.Objects of the present disclosure are not limited to the above-described objects, and other objects and advantages of the present disclosure that are not described above can be understood from the following description and can be clearly understood based on embodiments of the present disclosure. Also, it can be seen that the objects and advantages of the present disclosure can be realized by means described in the claims and a combination thereof.In an embodiment, a device for controlling a measurement of a cell voltage of a fuel cell includes a plurality of terminals connected between cells of a fuel cell connected in series, first resistors each connected in series to a plurality of terminals, a plurality of capacitors all connected in parallel between the first resistors and configured to store voltages, a plurality of switches each connected to the first resistors and configured to switch to a closed state or an open state, so that cell voltage measurement or wire breakage diagnosis is performed; a second resistor connected in series between the (-) pole of the lowest cell of the cells of the fuel cell and a semiconductor GND, configured to provide a path on which a current flows when an inverse voltage is generated in the cells of the fuel cell, a diode connected in parallel to the second resistor, configured to provide a path on which a current flows when an inverse voltage is not generated in the cells of the fuel cell, and a controller configured to change the state of each of the plurality of switches depending on a cell voltage measurement mode or a wire breakage diagnosis mode, and perform cell voltage measurement and wire breakage diagnosis.Further, the controller is configured to maintain the state of the plurality of switches in the open state in the cell voltage measurement method and maintain the state of the plurality of switches in the closed state in the wire breakage diagnosis mode.Further, the diode provides a path on which a current flows when no inverse voltage is generated in the fuel cell in the cell voltage measurement mode or the wire breakage diagnosis mode.Further, the second resistor provides a path on which a reverse current flows when an inverse voltage is generated in a cell of a fuel cell in the cell voltage measurement mode.Further, the controller may be configured to compare a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode, and determine that a wire breakage has occurred depending on whether a voltage difference is greater than a specific threshold.In an embodiment, a method for controlling a measurement of a cell voltage of a fuel cell includes changing a state of each of a plurality of switches connected to first resistors, respectively, depending on a cell voltage measurement mode or a wire breakage diagnosis mode, the first resistors being connected in series to a plurality of terminals connected between cells of the fuel cell connected in series, respectively, in the cell voltage measurement mode and the wire breakage diagnosis mode, providing a path on which a current flows through a diode, and determining whether a wire breakage occurs based on a voltage difference between voltages measured at a plurality of capacitors all connected in parallel between the first resistors, and providing a path on which a reverse current flows through a second resistor, when an inverse voltage is generated in the cell voltage measurement mode, the second resistor (120) being connected in series between a (-) pole of a lowermost cell of the cells of the fuel cell and a semiconductor ground, the diode (130) being connected in parallel to the second resistor (120) and configured to provide a path such that a current flows when an inverse voltage is not generated in the cells of the fuel cell.Further, changing the state of each of the plurality of switches respectively connected to the first resistors depending on the cell voltage measurement mode or the wire breakage diagnosis mode includes changing the state of each of the plurality of switches to an open state in the cell voltage measurement mode, and changing the state of each of the plurality of switches to a closed state in the wire breakage diagnosis mode.Further, determining whether a wire breakage occurs based on the voltage difference includes providing a path such that a current flows through first resistors connected to the plurality of switches, respectively, and the diode in the cell voltage measurement mode or the wire breakage diagnosis mode.Further, determining whether a wire breakage occurs based on the voltage difference includes comparing a voltage of a capacitor connected to the first resistor in the cell voltage measurement mode with a voltage of the capacitor in the wire breakage diagnosis mode, and determining whether a wire breakage has occurred depending on whether a voltage difference is greater than a specific threshold.Further, the method further includes determining that a wire break has occurred when a difference between voltages of capacitors of adjacent cells in the cell voltage measurement mode is greater than a specific threshold.BRIEF DESCRIPTION OF THE DRAWINGSFIG. is a diagram illustrating the principle of a fuel cell. FIG. 2 is a circuit diagram for describing an internal configuration of a known device for controlling measurement of a cell voltage of a fuel cell. FIG. 3 is a circuit diagram for describing an internal configuration of a device for controlling measurement of a cell voltage of a fuel cell according to an embodiment of the present disclosure. FIG. 4 is a circuit diagram for describing an internal configuration of a device for controlling measurement of a cell voltage of a fuel cell according to another embodiment of the present disclosure. FIG. 5 is a circuit diagram for describing an internal configuration of a device for controlling measurement of a cell voltage of a fuel cell according to another embodiment of the present disclosure. FIG. 6 is a flow chart for describing an embodiment of a method for controlling measurement of a cell voltage of a fuel cell according to the present disclosure. FIG. 7 is a flowchart for describing another embodiment of a method of controlling measurement of a cell voltage of a fuel cell according to the present disclosure.DETAILED DESCRIPTIONHereinafter, a method of controlling measurement of a cell voltage of a fuel cell and a device for carrying it out will be described with reference to the accompanying drawings through various examples of embodiments.The above-described objects, characteristics, and advantages will be described in detail with reference to the accompanying drawings, and thus a person having ordinary knowledge in the art to which the present disclosure pertains can easily practice the technical spirit of the present disclosure. Further, in describing the present disclosure, a detailed description of the related art related to the present disclosure will be omitted if it is assumed to unnecessarily obscure the spirit of the present disclosure. Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. In the same drawings, the same reference numerals are used to designate the same or similar elements.FIG. 2 is a circuit diagram for describing an internal configuration of a known device 10 for controlling measurement of a cell voltage of a fuel cell.Referring to FIG. 2, the cell voltage measurement control apparatus 10 includes a plurality of terminals 11_ 1, 11_ 2, and 11_ 3 between which the cells of a fuel cell are connected, respectively, a plurality of resistors R 1 to Rn connected in series to the plurality of terminals 11_ 1, 11_ 2, and 11_ 3, respectively, a plurality of capacitors C 1 to Cn connected between the plurality of resistors R 1 to Rn and configured to store voltages, and a plurality of switches S 1 to Sn connected to the plurality of resistors R 1 to Rn, respectively.The plurality of terminals 11_ 1, 11_ 2, and 11_ 3 are connected to the cells of each fuel cell, and are connected in series to the first resistors R 1 to Rn, respectively. For example, the plurality of terminals 11_ 1 to 11_n may be implemented as a (+) stage and a (-) stage.The plurality of resistors R 1 to Rn are connected in series to the plurality of terminals 11_ 1, 11_ 2, and 11_ 3, respectively, and provide paths on which currents applied from the respective terminals 11_ 1, 11_ 2, and 11_ 3 flow. The currents passing through the plurality of resistors R 1 to Rn are applied to a cell voltage measurement semiconductor.However, when an inverse voltage (for example, -1 V based on each cell) is generated in the fuel cell, a reverse current is applied to the cell voltage measurement semiconductor through the plurality of resistors R 1 to Rn. In such a case, there is a problem that the cell voltage measurement semiconductor can burn due to low tolerance for inverse voltage.The plurality of capacitors C 1 to Cn are connected in parallel between the plurality of resistors R 1 to Rn. For example, the first capacitor C 1 may be connected between any one of two (for example, R 1 and R 2) of the plurality of resistors. The second capacitor C 2 may be connected between any two (for example, R 2 and R 3) of the plurality of resistors. In this case, the first capacitor C 1 and the second capacitor C 2 may be connected in series.Each of the plurality of switches S 1 to Sn maintains a closed state or an open state such that cell voltage measurement or wire breakage diagnosis is performed by the cell voltage measurement semiconductor.In an embodiment, each of the plurality of switches S 1 to Sn remains in an open state, so that the cell voltage measurement is performed by the fuel cell voltage measurement semiconductor.As described above, each of the plurality of switches S 1 to Sn maintains an open state and cell voltage measurement is performed by the fuel cell measurement semiconductor, currents applied from the plurality of terminals 11_ 1, 11_ 2, and 11_ 3 are applied to the cell voltage measurement semiconductor by each of the plurality of resistors R 1 to Rn.However, when an inverse voltage (e.g., -1 V based on each cell) is generated in the fuel cell, a reverse current is applied to the cell voltage measurement semiconductor through the plurality of resistors R 1 to Rn. In such a case, there is a problem that the cell voltage measurement semiconductor can burn due to a low tolerance for the inverse voltage.Further, if each of the plurality of switches S 1 to Sn maintains a closed state and wire breakage diagnosis is performed by the fuel cell voltage measurement semiconductor, a high current flows because a current for wire breakage diagnosis of all the channels flows. A large voltage drop occurs in a second resistor because the high current flows through the second resistor. Accordingly, there is a need for a method of preventing misdiagnosis because a normal circuit is erroneously diagnosed as a wire breakage.FIGS. 3 and 4 are circuit diagrams for describing an internal configuration of a device 100 for controlling measurement of a cell voltage of a fuel cell according to an embodiment of the present disclosure.Referring to FIGS. 3 and 4, the apparatus 100 for controlling measurement of a cell voltage of a fuel cell includes a plurality of terminals 110_ 1 to 110_n between which each of the cells of a fuel cell connected in series, first resistors R 1 to Rn connected to the plurality of terminals 110_ 1 to 110_n, respectively, a plurality of capacitors C 1 to Cn connected in parallel between the first resistors R 1 to Rn and configured to store voltages, a second resistor 120 connected in series between the (-) pole of the lowermost cell V 1 of the cells of the fuel cell and a semiconductor ground and configured to provide a path on which a current flows when an inverse voltage is generated in a cell of the fuel cell, a diode 130 connected in parallel to the second resistor 120, a plurality of switches S 1 to Sn connected to the first resistors R 1 to Rn, respectively, and a controller 140 configured to control the plurality of switches S 1 to Sn and perform cell voltage measurement and wire breakage diagnosis.The plurality of terminals 110_ 1 to 110_n are connected to the cells of the fuel cell, and are connected in series to the first resistors R 1 to Rn, respectively. For example, the plurality of terminals may be implemented as a (+) stage and a (-) stage.The first resistors R 1 to Rn are connected in series to the plurality of terminals 110_ 1 to 110_n, respectively, and provide paths on which currents applied from the respective terminals 110_ 1 to 110_n flow. Currents passing through the first resistors R 1 to Rn are applied to a cell voltage measurement semiconductor.The plurality of capacitors C 1 to Cn are connected in parallel between the first resistors R 1 to Rn.The diode 130 is connected in parallel to the second resistor 120. If an inverse voltage is not generated in the fuel cell, the diode provides a path on which a current flows in a cell voltage measurement mode or a wire breakage diagnosis mode.If each of the plurality of switches S 1 to Sn maintains an open state as in FIG. 3, the fuel cell operates in the cell voltage measurement mode. If the fuel cell operates in the cell voltage measurement mode as in FIG. 3, no current flows through the plurality of switches S 1 to Sn and the first resistors connected to the respective switches S 1 to Sn because each of the plurality of switches S 1 to Sn maintains an open state.Accordingly, a current measured in the cell voltage measurement mode is lower than a current measured in the wire breakage diagnosis mode. Accordingly, the current does not flow through the second resistor 120 and flows through the diode 130.If each of the plurality of switches S 1 to Sn maintains a closed state as in FIG. 4, the fuel cell operates in a wire breakage diagnosis mode. If the fuel cell operates in the wire breakage diagnosis mode as in FIG. 4, a current flows through the plurality of switches S 1 to Sn and the first resistors connected to the respective switches S 1 to Sn because each of the plurality of switches S 1 to Sn maintains the closed state.Accordingly, a current flowing in the wire breakage diagnosis mode is higher than a current flowing in the cell voltage measurement mode. When the current flows through the second resistor 120, a voltage drop by the second resistor becomes large. Accordingly, the diode 130 is connected in parallel with the second resistor 120, so that the current flows through the diode 130.Each of the plurality of switches S 1 to Sn maintains an open state in the cell voltage measurement mode and a closed state in the wire breakage diagnosis mode under the control of the controller 140.The controller 140 changes the state of each of the plurality of switches depending on the cell voltage measurement mode or the wire breakage diagnosis mode, and performs cell voltage measurement and wire breakage diagnosis.To this end, in the cell voltage measurement mode, the controller 140 maintains the state in the plurality of switches S 1 to Sn to an open state, and then measures a cell voltage. In the wire breakage diagnosis mode, the controller 140 maintains the state of each of the plurality of switches S 1 to Sn in a closed state, and then measures the cell voltage in the state in which a diagnosis current is caused to flow.Next, a process of operating, by the controller 140, in the wire breakage diagnosis mode by maintaining the state of each of the plurality of switches S 1 to Sn in a closed state will be described.The controller 140 compares a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode, and determines that a wire breakage has occurred depending on whether a voltage difference is a specific threshold value or greater.In one embodiment, the controller 140 compares a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode, and determines that a wire breakage has occurred if a voltage difference is greater than a specified threshold.In another embodiment, the controller 140 compares a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode, and determines that no wire breakage has occurred if a voltage difference is a specific threshold or less.In the above embodiment, the controller 140 determines that wire breakage has occurred if a difference between voltages of capacitors of adjacent cells measured in the cell voltage measurement mode is a specific threshold value or greater.FIG. 5 is a circuit diagram for describing an internal configuration of a device 100 for controlling measurement of a cell voltage of a fuel cell according to another embodiment of the present disclosure.Referring to FIG. 5, the apparatus 100 for controlling measurement of a cell voltage of a fuel cell includes a plurality of terminals 110_ 1 to 110_n between which each of cells of a fuel cell connected in series, first resistors R 1 to Rn connected to the plurality of terminals 110_ 1 to 110_n, respectively, a plurality of capacitors C 1 to Cn connected in parallel between the first resistors R 1 to Rn and configured to store voltages, a second resistor 120 connected in series between the (-) pole of the lowermost cell V 1 of cells of the fuel cell and a semiconductor ground, and configured to provide a path on which a current flows when an inverse voltage is generated in a cell of the fuel cell, a diode 130, which is connected in parallel to the second resistor 120 and is configured to provide a path on which a current flows when an inverse voltage is not generated in a cell of the fuel cell, a plurality of switches S 1 to Sn connected to the first resistors R 1 to Rn, respectively, and a controller 140 configured to control the plurality of switches S 1 to Sn and perform cell voltage measurement and wire breakage diagnosis.The plurality of terminals 110_ 1 to 110_n are connected to the cells of the fuel cell, and are connected in series to the first resistors R 1 to Rn, respectively. For example, the plurality of terminals may be implemented as a (+) stage and a (-) stage.The first resistors R 1 to Rn are respectively connected in series to the plurality of terminals 110_ 1 to 110_n, and provide paths on which currents applied from the respective terminals 110_ 1 to 110_n flow. Currents passing through the first resistors R 1 to Rn are applied to a cell voltage measurement semiconductor.However, when an inverse voltage (for example, -1 V based on each cell) is generated in a cell of the fuel cell, a reverse current is applied to the cell voltage measurement semiconductor through the plurality of resistors R 1 to Rn. In such a case, there is a problem that the cell voltage measurement semiconductor can burn due to a low tolerance for this inverse voltage.As described above, the present disclosure can prevent the firing of the cell voltage measurement semiconductor due to an inverse voltage by restricting a reverse current in such a manner that when the inverse voltage is generated in a cell of the fuel cell, the reverse current does not directly flow into the ground of the cell voltage measurement semiconductor via the first resistors R 1 to Rn, but is caused to flow into the ground of the cell voltage measurement semiconductor via the second resistor 120. Such a process is described more specifically below with reference to the second resistor 120.The plurality of capacitors C 1 to Cn are connected in parallel between the first resistors R 1 to Rn. For example, the first capacitor C 1 may be connected between any two (e.g., R 1 and R 2) of the first resistors R 1 to Rn, and the second capacitor C 2 may be connected between any one (e.g., R 2 and R 3) of the first resistors R 1 to Rn. In this case, the first capacitor C 1 and the second capacitor C 2 may be connected in series.The second resistor 120 is connected in series between the (-) pole of the lowest cell V 1 of the cells of the fuel cell and the semiconductor ground, and provides a path on which a current flows depending on whether an inverse voltage is generated in the fuel cell.If the state of each of the plurality of switches S 1 to Sn maintains an open state and the fuel cell operates in a cell voltage measurement mode, the second resistor 120 provides a path on which a current flows when an inverse voltage is generated in a cell of the fuel cell.In such a case, currents flowing through the first resistors R 1 to Rn do not directly flow into the ground of the cell voltage measurement semiconductor but flow through the second resistor 120. Accordingly, the firing of the cell voltage measurement semiconductor ascribable to the inverse voltage can be prevented by restricting the reverse current.The diode 130 is connected in parallel to the second resistor 120. If no inverse voltage is generated in the fuel cell, the diode 130 provides a path on which a current flows in the cell voltage measurement mode or a wire breakage diagnosis mode.In a conventional technology, the second resistor 120 is not provided as illustrated in FIG. 2. Accordingly, when an inverse voltage is generated in a cell of the fuel cell, a reverse current directly flows into the cell voltage measurement semiconductor through the resistor R 1 of the first resistors R 1 to R 3. In such a case, there is a problem that the cell voltage measurement semiconductor can burn due to a lower tolerance for the inverse voltage.In order to prevent the problem, the present disclosure provides a path in which a reverse current does not flow through the second resistor 120, through the resistor R 1, when an inverse voltage is generated in the fuel cell depending on an operation of the controller 140, by adding the second resistor 120 in series instead of a flow of a current flowing into the resistor R 1 of the first resistors R 1 to R 3.Accordingly, the present disclosure can prevent the firing of the fuel cell voltage measurement semiconductor that is attributeable to an inverse voltage by limiting a reverse current in such a manner that the reverse current flows through the second resistor 120 when the inverse voltage is generated.Each of the plurality of switches S 1 to Sn maintains an open state in a cell voltage measurement mode and a closed state in a wire breakage diagnosis mode under the control of the controller 140. If an inverse voltage is generated when the controller 140 operates in the cell voltage measurement mode or the wire breakage diagnosis mode, the controller 140 controls a current to flow through the second resistor 120. If an inverse voltage is not generated, the controller 140 controls a current to flow through the diode 130.To this end, the controller 140 maintains the state of each of the plurality of switches S 1 to Sn in an open state in the cell voltage measurement mode, and maintains the state of each of the plurality of switches S 1 to Sn in a closed state in the wire breakage diagnosis mode.Next, a process of operating, by the controller 140, in a cell voltage measurement mode by maintaining the state of each of the plurality of switches S 1 to Sn at an open state will be described.The controller 140 measures a cell voltage in the state in which the state of each of the plurality of switches S 1 to Sn has been maintained at the open state in the cell voltage measurement mode. At this time, the controller 140 provides a path such that a current flows through the second resistor 120 depending on whether an inverse voltage has been generated in the process of measuring the cell voltage in the cell voltage measurement mode.In the above embodiment, the controller 140 provides a path in which a reverse current flows through the second resistor 120 when an inverse voltage is generated in a cell of the fuel cell. As described above, the present disclosure controls the reverse current to flow through the second resistor 120 when the inverse voltage is generated, and thus can prevent the firing of the fuel cell voltage measurement semiconductor that is attributeable to the inverse voltage by limiting the reverse current.FIG. 6 is a flow chart for describing an embodiment of a method for controlling motor control of a cell voltage of a fuel cell according to the present disclosure.Referring to FIG. 6, the cell voltage measurement controller 100 of a fuel cell changes the state of each of the plurality of switches depending on a cell voltage measurement mode or a wire breakage diagnosis mode (step S 610).In an embodiment of step S 610, the cell voltage measurement control device 100 of a fuel cell changes the state of each of the plurality of switches to an open state when the cell voltage measurement mode is operated.In another embodiment of step S 610, the cell voltage measurement control device 100 of a fuel cell changes the state of each of the plurality of switches to a closed state when operated in the wire breakage diagnosis mode.The means 100 for controlling the measurement of a cell voltage of a fuel cell checks whether an inverse voltage has been generated in the fuel cell when the means operates in the cell voltage measurement mode (step S 620).If an inverse voltage is generated (step S630), the cell voltage measurement control means 100 provides a path on which a current flows through the second resistor connected in series to the (-) pole of the lowest cell of the cells of the fuel cell and the semiconductor ground (step S640).As described above, the present disclosure has an advantage in that it can prevent the firing of the fuel cell voltage measurement semiconductor that is attributable to an inverse voltage by limiting a reverse current in such a manner that the reverse current flows through the second resistor when the inverse voltage is generated.FIG. 7 is a flowchart for describing another embodiment of a method of controlling measurement of a cell voltage of a fuel cell according to the present disclosure.Referring to FIG. 7, the cell voltage measurement controller 100 of a fuel cell changes the state of each of the plurality of switches depending on a cell voltage measurement mode or a wire breakage diagnosis mode (step S 710).In an embodiment of step S 710, the cell voltage measurement controller 100 changes the state of each of the plurality of switches to an open state when operating in the cell voltage measurement mode.In another embodiment of step S 710, the cell voltage measurement control device 100 of a fuel cell changes the state of each of the plurality of switches to a closed state when operated in the wire breakage diagnostic mode.The cell voltage measurement control device 100 compares a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode (step S 72).If a voltage difference is larger than a specific threshold (step S 730), the cell voltage measurement control device 100 determines that a wire breakage has occurred (step S 740).If the voltage difference is the specific threshold value or less (step S 730), the cell voltage measurement control device 100 determines that wire breakage has not occurred (step S 750).Alternatively, the device 100 compares voltages of capacitors of adjacent cells in the cell voltage measurement mode. If a voltage difference is greater than a specific threshold, the device 100 determines that a wire break has occurred.According to the present disclosure described above, if an inverse voltage is generated when a battery cell operates in a cell voltage measurement mode, a reverse current flows through a resistor having a higher resistance value than a separate cell voltage measurement circuit, not a resistor of a cell voltage measurement circuit. Accordingly, there is an advantage in that the firing of a fuel cell voltage measurement semiconductor attributable to an inverse voltage can be prevented by limiting a reverse continuous current.Further, according to the present disclosure, there is an advantage that a voltage drop in a resistor can be prevented because a current flows through a diode (not the resistor) when a battery cell operates in a cell voltage measurement mode or a wire breakage diagnosis mode.Although preferred embodiments of the disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and omissions are possible without departing from the scope and spirit of the disclosure as defined in the appended claims. Thus, the true technical scope of the disclosure should be defined by the following claims.

Claims

An apparatus for controlling a measurement of a cell voltage of a fuel cell, characterized in that the apparatus comprises: a plurality of terminals (110_1 - 110_n) connected between cells of a fuel cell connected in series; first resistors (R1 - Rn) each connected in series to a plurality of terminals (110_1 - 110_n); a plurality of capacitors (C1 - Cn) all connected in parallel between the first resistors (R1 - Rn) and configured to store voltages; a plurality of switches (S1-Sn) connected to the first resistors (R1-Rn), respectively, and configured to switch to a closed state or an open state, a second resistor (120) connected in series between the (-) pole of the lowermost cell of the cells of the fuel cell and a semiconductor ground, configured to provide a path on which a current flows when an inverse voltage is generated in the cells of the fuel cell; a diode (130) connected in parallel to the second resistor (120), configured to provide a path on which a current flows when an inverse voltage is not generated in the cells of the fuel cell; and a controller (140) configured to change the state of each of the plurality of switches (S1-Sn) depending on a cell voltage measurement mode or a wire breakage diagnosis mode, and perform cell voltage measurement and wire breakage diagnosis.The apparatus of claim 1, wherein the controller (140) is configured to maintain the state of the plurality of switches (S1 - Sn) in the open state in the cell voltage measurement method, and maintain the state of the plurality of switches (S1 - Sn) in the closed state in the wire breakage diagnosis mode.The apparatus of claim 1, wherein the diode (130) provides a path on which a current flows depending on an operation of the controller (140) in the cell voltage measurement mode or the wire breakage diagnosis mode.The device of claim 1, wherein the second resistor (120) provides a path on which a reverse current flows depending on an operation of the controller (140) when an inverse voltage is generated in a cell of a fuel cell in the cell voltage measurement mode.The apparatus of claim 1, wherein the controller (140) is configured to: compare a voltage of a capacitor measured in the cell voltage measurement mode with a voltage of the capacitor measured in the wire breakage diagnosis mode, and determine that a wire breakage has occurred depending on whether a voltage difference is greater than a specific threshold.A method for controlling a measurement of a cell voltage of a fuel cell, characterized in that the method comprises: changing a state of each of a plurality of switches (S1 - Sn) connected to first resistors (R1 - Rn), respectively, depending on a cell voltage measurement mode or a wire breakage diagnosis mode, wherein the first resistors (R1 - Rn) are connected in series to a plurality of terminals (110_1 - 110_n) connected between cells of the fuel cell connected in series, respectively, in the cell voltage measurement mode and the wire breakage diagnosis mode, providing a path such that a current flows through a diode (130), and determining whether a wire breakage occurs based on a voltage difference between voltages, measuring across a plurality of capacitors (C1 - Cn) all connected in parallel between the first resistors (R1 - Rn); and providing a path on which a reverse current flows through a second resistor (120) when an inverse voltage is generated in the cell voltage measurement mode, the second resistor (120) being connected in series between a (-) pole of a lowermost cell of the cells of the fuel cell and a semiconductor ground; wherein the diode (130) is connected in parallel to the second resistor (120) and is configured to provide a path on which a current flows when an inverse voltage is not generated in the cells of the fuel cell.The method of claim 6, wherein changing the state of each of the plurality of switches (S1 - Sn) respectively connected to the first resistors (R1 - Rn) depending on the cell voltage measurement mode or the wire breakage diagnosis mode comprises: changing the state of each of the plurality of switches (S1 - Sn) to an open state in the cell voltage measurement mode; and changing the state of each of the plurality of switches (S1 - Sn) to a closed state in the wire breakage diagnosis mode.The method of claim 7, wherein the determining whether a wire breakage occurs based on the voltage difference comprises: providing a path such that a current flows through first resistors (R1 - Rn) respectively connected to the plurality of switches (S1 - Sn), and the diode (130) in the cell voltage measurement mode or the wire breakage diagnosis mode.The method according to claim 8, wherein the determining whether a wire breakage occurs based on the voltage difference comprises: comparing a voltage of a capacitor connected to the first resistor (R1 - Rn) in the cell voltage measurement mode with a voltage of the capacitor in the wire breakage diagnosis mode, and determining whether a wire breakage has occurred depending on whether a voltage difference is larger than a specific threshold value.The method of claim 6, further comprising determining that a wire break has occurred when a difference between voltages of capacitors of adjacent cells in the cell voltage measurement mode is greater than a specific threshold.

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