Control system and method for preventing fuel cell overheating

Abstract

Disclosed are a control system and method for preventing overheating of a fuel cell. The system includes: a fuel cell that generates electric power through reaction of a fuel gas and an oxidizing gas; a cooling line through which a cooling medium flows and exchanges heat with the fuel cell; a cooling pump installed on the cooling line and configured to circulate the cooling medium through the cooling line; a cooling controller that controls an operating state of the cooling pump based on a temperature of the fuel cell or the cooling medium; and a power generation controller that limits power generation of the fuel cell based on the operating state of the cooling pump.

Description

Technical Field

[0001] This disclosure relates to a control system and method for preventing overheating of a fuel cell. More specifically, this disclosure relates to a technique for preventing fuel cell overheating by adaptively limiting the power generation of the fuel cell through the operating state of a cooling pump based on the circulating coolant. Background Technology

[0002] A fuel cell is a generator that directly converts the chemical energy produced by the oxidation of fuel into electrical energy. The fundamental similarity between a fuel cell and a chemical battery lies in their use of oxidation and reduction reactions. However, a chemical battery is a closed reaction system, while a fuel cell is an open reaction system, with reactants continuously supplied and reaction products continuously discharged. In recent years, fuel cells have been put into practical use. Furthermore, because the reaction product of a fuel cell is pure water, research has been actively conducted on using this type of fuel cell as an energy source for environmentally friendly vehicles.

[0003] A fuel cell includes a fuel cell stack that generates electricity through a chemical reaction, an air supply device that supplies air to the air electrode (cathode) of the fuel cell stack, and a hydrogen supply device that supplies hydrogen to the hydrogen electrode (anode) of the fuel cell stack. Specifically, oxygen-containing air is supplied to the air electrode (cathode) of the fuel cell stack, and hydrogen is supplied to the hydrogen electrode (anode) of the fuel cell stack.

[0004] In terms of thermal damage, fuel cell stacks are physically less robust than traditional internal combustion engines. Due to thermal damage, fail-safe strategies for diagnosing and managing overheating in fuel cell stacks have become a critical issue.

[0005] Typically, because it is difficult to directly sense the internal temperature of a fuel cell stack, control for cooling the fuel cell is based on the temperature of the coolant flowing out of the fuel cell stack. Therefore, when the temperature sensor sensing the coolant temperature at the fuel cell stack outlet malfunctions, there is a problem of being unable to handle fuel cell stack overheating.

[0006] The foregoing is intended only to help understand the background of this disclosure. The foregoing does not imply that this disclosure falls within the scope of the technology known to those skilled in the art. Summary of the Invention

[0007] This disclosure is made to address the problems that have arisen in the art. The purpose of this disclosure is to provide a technique for preventing fuel cell overheating by limiting the power generation of the fuel cell through the operation of a cooling pump that cools the fuel cell based on a circulating coolant.

[0008] According to one aspect of this disclosure, a control system for preventing overheating of a fuel cell is provided, the system comprising: a fuel cell that generates electrical energy through a reaction between fuel gas and oxidizing gas; a cooling line connected to the fuel cell such that a cooling medium flowing through the cooling line exchanges heat with the fuel cell; a cooling pump mounted on the cooling line and configured to circulate the cooling medium through the cooling line when a cooling pump is driven; a cooling controller that controls the operating state of the cooling pump based on the temperature of the fuel cell or the cooling medium; and a power generation controller that limits the power generation of the fuel cell based on the operating state of the cooling pump.

[0009] The cooling piping can be equipped with a radiator, through which the cooling medium exchanges heat with the outside air. The cooling piping can be connected to the radiator and the inlet and outlet of the fuel cell. A cooling pump can pump the cooling medium so that some or all of the cooling medium discharged from the fuel cell outlet flows to the radiator, or so that the cooling medium discharged from the radiator flows to the fuel cell inlet.

[0010] The system may also include a temperature sensor mounted on the cooling line and positioned near the fuel cell outlet. The temperature sensor can be configured to sense the temperature of the cooling medium. The cooling controller can then control the operation of the cooling pump based on the temperature of the cooling medium.

[0011] The cooling controller can control the cooling pump so that its actual speed follows a reference speed set based on the temperature of the fuel cell or the cooling medium. The power generation controller can adaptively limit the amount of electricity generated by the fuel cell based on the speed difference between the actual and reference speeds of the cooling pump.

[0012] The power generation controller can limit the electricity generated by the fuel cell to be equal to or less than a preset reference power generation based on the temperature of the fuel cell or cooling medium. The power generation controller can also apply a first offset value set based on the speed difference to the temperature of the fuel cell or cooling medium or the reference power generation.

[0013] When the speed difference is equal to or greater than the preset speed difference value, the power generation controller can set a first offset value so that as the speed difference increases, the temperature of the fuel cell or cooling medium gradually decreases or gradually decreases with reference to the power generation.

[0014] The power generation controller can limit the amount of electricity generated by the fuel cell based on the power consumption difference between a preset reference power consumption based on the cooling pump speed and the actual power consumption of the cooling pump.

[0015] The power generation controller adaptively limits the amount of electricity generated by the fuel cell only when the actual speed of the cooling pump is equal to or higher than the preset reference speed.

[0016] The power generation controller can limit the power generated by the fuel cell to be equal to or less than a reference power generation amount based on the temperature of the fuel cell or cooling medium. When the actual power consumption of the cooling pump is equal to or less than the preset reference power consumption amount, the power generation controller applies a second offset value set based on the power consumption difference to either the temperature of the fuel cell or cooling medium or the reference power generation amount.

[0017] When the power consumption difference is equal to or greater than the preset power consumption difference, the power generation controller can set a second offset value so that the temperature of the fuel cell or cooling medium gradually decreases or the reference power generation gradually decreases as the power consumption difference increases.

[0018] When the actual power consumption of the cooling pump is greater than the reference power consumption difference, the cooling controller can increase the cooling capacity of the cooling pump based on the power consumption difference.

[0019] According to another aspect of this disclosure, a control method for preventing overheating of a fuel cell is provided, the method comprising: estimating the temperature of the fuel cell or sensing the temperature of a cooling medium; controlling the operating state of a cooling pump that circulates the cooling medium through a cooling pipe connected to the fuel cell based on the estimated temperature of the fuel cell or the sensed temperature of the cooling medium; and adaptively limiting the power generation of the fuel cell according to the operating state of the cooling pump.

[0020] In the control of the operating state, the cooling pump can be controlled so that its actual rotational speed follows a reference rotational speed set based on the temperature of the fuel cell or cooling medium. The method also includes calculating the speed difference between the actual rotational speed of the cooling pump and the reference rotational speed, wherein this calculation is performed before limiting the power output. In power limiting, the power output generated by the fuel cell is limited based on the calculated speed difference.

[0021] In the power limitation, the power generation of the fuel cell is limited to be equal to or less than a reference power generation set based on the temperature of the fuel cell or cooling medium. Additionally, a first offset value set based on the speed difference is applied to either the temperature of the fuel cell or cooling medium or the reference power generation.

[0022] The method may further include calculating a power consumption difference, which is the difference between the actual power consumption of the cooling pump and a reference power consumption preset based on the cooling pump's rotational speed, wherein the calculation is performed before limiting the power output. In the limiting process, the power output generated by the fuel cell can be limited based on the calculated power consumption difference.

[0023] Within the limitations, the electricity generated by the fuel cell is restricted to be equal to or less than a reference power generation preset based on the temperature of the fuel cell or cooling medium. When the actual power consumption of the cooling pump is less than the reference power consumption, a second offset value set according to the power consumption difference is applied to the temperature of the fuel cell or cooling medium or to the reference power generation.

[0024] The method may further include: increasing the cooling capacity of the cooling pump based on the power consumption difference when the actual power consumption of the cooling pump is greater than the reference power consumption. The increase in cooling capacity can be performed after calculating the power consumption difference.

[0025] Even if there is a temperature difference between the fuel cell and the cooling medium, the control system and method according to this disclosure can prevent the fuel cell from overheating by performing adaptive control based on the operating state of the cooling pump. Attached Figure Description

[0026] The above and other objects, features and advantages of this disclosure should be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 This is a schematic diagram illustrating the construction of an overheat control system for a fuel cell according to an embodiment of the present disclosure;

[0028] Figure 2 It is a graph showing the relationship between the speed difference and the first offset value according to an embodiment of the present disclosure;

[0029] Figure 3 This is a power consumption curve based on the rotational speed of the cooling pump according to an embodiment of the present disclosure;

[0030] Figure 4 This is a flowchart illustrating the relationship between the power consumption difference and the second offset value according to an embodiment of the present disclosure;

[0031] Figure 5 This is a graph showing the current limitation as a function of the cooling medium temperature according to an embodiment of the present disclosure; and

[0032] Figure 6 This is a flowchart illustrating an overheat control method for a fuel cell according to an embodiment of the present disclosure. Detailed Implementation

[0033] Reference should now be made to the accompanying drawings, in which the same reference numerals are used in different drawings to denote the same or similar parts.

[0034] The specific structural or functional descriptions of the embodiments disclosed in this application specification are for illustrative purposes only. This disclosure can be embodied in various forms and should not be construed as being limited to the embodiments described in this application specification.

[0035] Various embodiments are possible based on the concepts of this disclosure, and only a few embodiments are shown in the accompanying drawings, which are described in detail below. Although specific embodiments of this disclosure are described below, they are for illustrative purposes only and should not be construed as limiting the disclosure. Therefore, this disclosure should be designed to cover not only the specific embodiments but also all modifications, equivalents, and substitutions falling within the concepts and spirit of this disclosure.

[0036] The terms "first," "second," etc., used in this specification are used to distinguish one element from another, but unless otherwise specified, the order or priority of the elements is not limited by these terms. Therefore, a first element in one embodiment may be referred to as a second element in another embodiment. Similarly, a second element in one embodiment may be referred to as a first element in another embodiment, used only for the purpose of distinguishing one element from another, without departing from the scope of this disclosure as claimed.

[0037] It should be understood that when any element is referred to as "connected" or "coupled" to another element, one element can be directly connected or coupled to the other element, or there can be an intermediate element between them. Conversely, it should be understood that when one element is referred to as "directly coupled" or "directly connected" to another element, there is no intermediate element between them. Other expressions describing the relationship between elements, such as "between," "directly between," "adjacent," and "directly adjacent," should be interpreted in the same way.

[0038] The terminology used herein is for descriptive purposes only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should be further understood that, when used in this disclosure, the terms “comprising,” “including,” or “having” specify the presence of the stated features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or combinations thereof.

[0039] Furthermore, unless otherwise defined, all terms, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should be further understood that terms, such as those defined in commonly used dictionaries, shall be interpreted as having a meaning consistent with their meaning in the context of this technology and this disclosure. Unless explicitly defined, these terms should not be interpreted in an idealized or overly formal sense.

[0040] The specific contents of this disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same elements.

[0041] Figure 1 This is a schematic diagram illustrating the construction of an overheat control system for a fuel cell 10 according to an embodiment of the present disclosure.

[0042] Reference Figure 1 According to one embodiment of this disclosure, an overheat control system for a fuel cell 10 includes: a fuel cell 10 for generating electrical energy through the reaction of fuel gas and oxidizing gas; a cooling line 20 connected to the fuel cell 10 and configured to be filled with a cooling medium that exchanges heat with the fuel cell 10; a cooling pump 30 mounted on the cooling line 20 and configured to circulate the cooling medium through the cooling line 20 when the cooling pump 30 is driven; a cooling controller 40 for controlling the operating state of the cooling pump 30 according to the temperature of the fuel cell 10 or the temperature of the cooling medium; and a power generation controller 50 for limiting the power generation of the fuel cell 10 based on the operating state of the cooling pump 30.

[0043] The cooling controller 40 and power generation controller 50 included in one embodiment of this disclosure may be implemented using the following: a non-volatile memory (not shown) is configured to store data related to an algorithm configured to control the operation of various components of the vehicle or associated with software instructions for executing the algorithm; and a processor (not shown) is configured to use the data stored in the non-volatile memory to perform the operations described below. The memory and processor are implemented using discrete chips. Alternatively, the memory and processor may be implemented using an integrated chip. In another alternative, the processor may be implemented using a processor array.

[0044] The fuel cell 10 is supplied with fuel gas and oxidizing gas. Specifically, the anode and cathode of the fuel cell 10 are supplied with fuel gas and oxidizing gas, respectively. For example, the fuel gas is hydrogen, and the oxidizing gas is oxygen-containing air. The fuel cell 10 generates electrical energy and heat energy through the chemical reaction of hydrogen and oxygen.

[0045] Cooling pipe 20 is a conduit through which a cooling medium flows, such as water. In other words, liquid cooling is used. The cooling medium circulates by flowing through cooling pipe 20, then into the inlet of fuel cell 10, through fuel cell 10, and out of the outlet of fuel cell 10.

[0046] A cooling pump 30 is mounted on a cooling line 20 to allow cooling medium to flow through the cooling line 20 when the pump 30 is driven. A cooling controller 40 controls the rotational speed of the cooling pump 30, thereby regulating the flow rate of the cooling medium.

[0047] The cooling controller 40 controls the drive of the cooling pump 30 based on the temperature of the cooling medium or the fuel cell 10. In one embodiment, the cooling controller 40 controls the cooling pump 30 such that the flow rate of the cooling medium increases as the temperature of the cooling medium or the fuel cell 10 increases.

[0048] Cooling controller 40 controls control valves to regulate the flow rate of cooling medium through radiator 21, which will be described later.

[0049] The power generation controller 50 controls the power generation of the fuel cell 10. Specifically, the power generation controller 50 limits the power generation of the fuel cell 10 based on the operating status of the cooling pump 30. More specifically, the power generation controller 50 limits the output current or output voltage of the fuel cell 10.

[0050] More specifically, the power generation controller 50 limits the output current or output voltage of the fuel cell 10 based on the temperature of the fuel cell 10 or the cooling medium. In one embodiment, the output current of the fuel cell 10 may be limited to be equal to or less than a reference current limit, which is set to vary according to the temperature of the fuel cell 10 or the cooling medium.

[0051] Specifically, the power generation controller 50 changes the reference current limit of the fuel cell 10 according to the operating status of the cooling pump 30.

[0052] Therefore, even if there is a temperature difference between the fuel cell 10 and the cooling medium, it has the effect of preventing the fuel cell from overheating because the operating state of the cooling pump 30 is taken into account when limiting the power generation of the fuel cell.

[0053] Cooling pipe 20 is equipped with radiator 21, in which cooling medium exchanges heat with outside air. Cooling pipe 20 is installed such that each of the inlet and outlet of fuel cell 10 is connected to radiator 21. Pump 30 directs some or all of the cooling medium discharged from the outlet of fuel cell 10 to radiator 21, or directs the cooling medium discharged from radiator to inlet of fuel cell 10.

[0054] The radiator 21 is, for example, a device that allows the cooling medium flowing through the cooling pipe 20 to exchange heat with the outside air.

[0055] The control system according to one embodiment of the present disclosure further includes a temperature sensor 22, which is mounted on the cooling line 20 and positioned near the outlet of the fuel cell 10. The temperature sensor 22 measures the temperature of the cooling medium flowing through the cooling line 20. The cooling controller 40 controls the operating state of the cooling pump 30 based on the temperature of the cooling medium.

[0056] The temperature of the cooling medium varies locally along the cooling pipe 20, and the temperature sensor 22 senses the temperature of the cooling medium discharged from the outlet of the fuel cell 10.

[0057] Furthermore, in this disclosure, the temperature of the fuel cell 10 is estimated based on the temperature of the cooling medium. Specifically, the temperature of the fuel cell 10 is estimated based on the temperature of the cooling medium, which is measured by a temperature sensor 22 at a location near the outlet of the fuel cell 10.

[0058] In one embodiment, the cooling controller 40 controls the cooling pump 30 such that the actual rotational speed of the cooling pump 30 increases as the detected temperature of the cooling medium or the estimated temperature of the fuel cell 10 increases.

[0059] Figure 2 It is a graph showing the relationship between the speed difference and the first offset value in one embodiment of this disclosure.

[0060] refer to Figure 2 The cooling controller 40 controls the cooling pump 30 so that the actual speed of the cooling pump 30 follows a reference speed set based on the temperature of the fuel cell 10 or the cooling medium. The power generation controller 50 controls the power generation (i.e., electricity) of the fuel cell 10 based on the difference between the preset reference speed and the actual speed of the cooling pump 30.

[0061] In one embodiment, the reference rotational speed is mapped to the temperature of the fuel cell 10 or to the temperature of the cooling medium.

[0062] The generator controller 50 calculates the speed difference between the reference speed (reference RPM) of the cooling pump 30 and the actual speed (actual RPM) of the cooling pump 30 according to the following equation.

[0063] △RPM = |Reference RPM - Actual RPM|

[0064] In another embodiment, the speed difference can be calculated using the equation “reference RPM command - actual RPM”, which does not produce absolute values. This is only used to a limited extent if the actual RPM does not follow the reference RPM, thus failing to guarantee cooling of the fuel cell 10.

[0065] The power generation controller 50 limits the power generation of the fuel cell 10 based on a calculated speed difference. Specifically, the power generation controller 50 sets a first offset value based on the calculated speed difference, which is applied to a reference power generation limit of the fuel cell 10.

[0066] The power generation controller 50 limits the power generation of the fuel cell 10 so that the power generated by the fuel cell 10 is equal to or less than a reference power generation preset based on the temperature of the fuel cell or cooling medium. Furthermore, the power generation controller applies a first offset value set based on the speed difference to the temperature of the fuel cell or cooling medium or to the reference power generation.

[0067] When the speed difference is equal to or greater than the preset speed difference, the generator controller sets the first offset value T. ro This causes the temperature of the fuel cell or cooling medium to gradually decrease or the reference power generation to gradually decrease as the speed difference increases.

[0068] In other words, when the speed difference is equal to or greater than a predetermined speed difference value, the generator controller 50 sets a first offset value T. ro This causes the first offset value to gradually increase as the speed difference increases.

[0069] In other words, such as Figure 2 As shown, when the speed difference is less than or equal to the predetermined speed difference value A, the first offset value T ro It is set to 0. On the other hand, when the speed difference is greater than or equal to the predetermined speed difference value A, the first offset increases as the speed difference value increases.

[0070] First offset value T ro It can be set to a negative value less than zero.

[0071] Figure 3 This is a graph showing the relationship between the power consumption and rotational speed of the cooling pump 30. Figure 4 This is a graph illustrating the relationship between a second offset value and power consumption difference according to an embodiment of the present disclosure.

[0072] Reference Figure 3 and Figure 4 The power generation controller 50 limits the power generation of the fuel cell 10 based on the power consumption difference between the actual power consumption of the cooling pump 30 and the reference power consumption predetermined according to the rotational speed of the cooling pump 30.

[0073] Specifically, this can be achieved by using a predetermined reference power consumption P. ref The power consumption difference ΔP is calculated by subtracting the actual power consumption P from the reference power consumption. Here, the reference power consumption is assumed to be the amount of power consumed by the cooling pump 30 when it is operating normally at a predetermined speed.

[0074] △P=P ref -P,

[0075] Specifically, only when the speed of the cooling pump 30 is higher than the preset speed (P) ref When ≥P, ΔP≥0), the power generation controller 50 limits the power generation of the fuel cell 10 according to the power consumption difference ΔP.

[0076] More specifically, when the power consumption difference ΔP is greater than C, i.e. greater than zero, the generator controller 50 sets a second offset value T based on the power consumption difference. po The generator controller 50 also applies a second offset value T. po To limit the power generation of fuel cell 10.

[0077] The power generation controller 50 limits the power generation of the fuel cell 10 so that the amount of electricity generated by the fuel cell 10 is equal to or less than a reference power generation preset based on the temperature of the fuel cell 10 or the cooling medium. The power generation controller will set a second offset value T based on the power consumption difference. po The temperature applied to fuel cell 10 or the cooling medium, or the temperature applied to the reference power generation.

[0078] like Figure 4 As shown, when the power consumption difference ΔP is equal to or greater than the preset power consumption difference value E, the generator controller 50 sets a second offset value T. po This causes the temperature of the fuel cell 10 or the cooling medium, which limits the power generation of the fuel cell 10, to gradually decrease or the reference power generation to gradually decrease as the power consumption difference ΔP increases.

[0079] Alternatively, when the power consumption difference ΔP is greater than or equal to the preset power consumption difference value E, the generator controller 50 sets a second offset value T. po This makes the second offset value T po The value increases with the increase of the power consumption difference ΔP.

[0080] Second offset value T po It can be set to a negative value less than zero.

[0081] In addition, the power generation controller 50 is based on the first offset value T ro Second offset value T po The final offset value is calculated, and the power generation of the fuel cell 10 is controlled based on the calculated final offset value. In one embodiment, the power generation controller 50 applies weights to the first offset value T. ro Second offset value T po To calculate the final offset value.

[0082] When the actual power consumption of the cooling pump 30 is greater than the preset reference power consumption, the cooling controller 40 increases the cooling capacity of the cooling pump 30 based on the power consumption difference ΔP.

[0083] Specifically, when the power consumption difference ΔP is less than D, that is, less than zero, the cooling controller 40 increases the cooling capacity of the cooling pump 30.

[0084] Here, the cooling pump 30 can be cooled by the circulation of additional coolant or air, and the cooling controller 40 can increase the cooling capacity of the cooling pump 30 by increasing the speed of the electric cooling pump or the electric radiator fan.

[0085] Additionally, when the first offset value T ro Second offset value T po Each of the values ​​is greater than or equal to a preset value, or the first offset value T. ro Second offset value T po If the sum is greater than or equal to a preset value, this situation is considered to be a state where cooling cannot be carried out due to excessive error. In this case, the power generation controller 50 shuts down the fuel cell 10.

[0086] Figure 5 This is a graph showing the current limit as a function of the temperature of the cooling medium, according to one embodiment of the present disclosure.

[0087] Reference Figure 5 The power generation controller 50 limits the power generation of the fuel cell 10 so that the amount of electricity generated by the fuel cell 10 is equal to or less than a reference current value, which varies according to the temperature of the cooling medium.

[0088] Specifically, when the temperature of the cooling medium is lower than or equal to the preset temperature, the reference current value is maintained. On the other hand, when the temperature of the cooling medium is higher than the preset temperature, the reference current value gradually decreases.

[0089] In one embodiment, the power generation controller 50 calculates as a first offset value T ro Second offset value T po The sum of the temperature offset values ​​and the calculated temperature offset value T offset The temperature applied to fuel cell 10 or the cooling medium, or the temperature applied to the reference power generation.

[0090] More specifically, the generator controller 50 will shift the temperature offset value T according to the reference current value curve of the temperature change of the cooling medium. offset Alternatively, the generator controller 50 can control the temperature offset value T. offset The reference current value is changed based on the sensed temperature of the cooling medium or the estimated temperature of the fuel cell 10.

[0091] In another embodiment, the power generation controller 50 uses T as the first offset value. ro Second offset value T po The sum of temperature offset values ​​T offset The reference current value is changed based on the detected temperature of the cooling medium or the estimated temperature of the fuel cell 10.

[0092] Figure 6 This is a flowchart illustrating an overheat control method for a fuel cell according to an embodiment of the present disclosure.

[0093] Reference Figure 6According to one embodiment of the present disclosure, a control method for preventing overheating of a fuel cell 10 includes: step S100, estimating the temperature of the fuel cell 10 or detecting the temperature of the cooling medium; step S200, based on the estimated temperature of the fuel cell 10 or the detected temperature of the cooling medium, driving a cooling pump 30 that circulates the cooling medium through a cooling pipe 20 connected to the fuel cell 10; and step S600, limiting the power generation of the fuel cell 10 based on the operating state of the cooling pump 30.

[0094] In step S200, the cooling pump 30 is controlled such that its actual rotational speed follows a reference rotational speed set based on the temperature of the fuel cell 10 or the cooling medium. The method further includes step S300, in which the speed difference between the actual rotational speed of the cooling pump 30 and the reference rotational speed is calculated. In step S600, the power generation of the fuel cell 10 is limited based on the calculated speed difference.

[0095] In step S600, which limits the power generation of the fuel cell 10, the power generation of the fuel cell 10 is limited to be equal to or less than a reference power generation preset based on the temperature of the fuel cell 10 or the cooling medium. Additionally, a first offset value set based on the speed difference is applied to the temperature of the fuel cell or the cooling medium, or to the reference power generation.

[0096] The method further includes step S400, in which the power consumption difference is calculated. The power consumption difference is the difference between the actual power consumption of the cooling pump 30 and a reference power consumption preset based on the rotational speed of the cooling pump 30. Step S400 is performed before step S600. In step S600, which limits the power generation of the fuel cell 10, the power generation of the fuel cell 10 is limited based on the calculated power consumption difference.

[0097] The method further includes step S310, wherein it is determined whether the rotational speed of the cooling pump 30 is equal to or higher than a preset reference rotational speed (P). ref ≥P, △P≥0). Step S310 is executed before step S400. The power generation of fuel cell 10 is limited only when the actual speed of cooling pump 30 is equal to or higher than the preset reference speed.

[0098] In step S600, which limits the power generation of the fuel cell 10, the power generation of the fuel cell 10 is limited to be equal to or less than a reference power generation preset based on the temperature of the fuel cell 10 or the cooling medium. When the actual power consumption of the cooling pump 30 is equal to or less than the preset reference power consumption (step S500), a second offset value set based on the power consumption difference is applied to the temperature of the fuel cell 10 or the cooling medium or to the reference power generation.

[0099] The method further includes step S700, wherein when the actual power consumption of the cooling pump 30 is greater than the reference power consumption, the cooling capacity of the cooling pump is increased based on the power consumption difference. Step S700 is executed after step S400.

[0100] Although only specific embodiments have been described, those skilled in the art will understand that various changes and variations are possible without departing from the scope and spirit of this disclosure.

Claims

1. A control system for preventing overheating of a fuel cell, the system comprising: A fuel cell is configured to generate electrical energy through the reaction of fuel gas and oxidizing gas. A cooling pipe through which a cooling medium flows, and in which the cooling medium exchanges heat with the fuel cell; A cooling pump is installed on the cooling line and configured to circulate the cooling medium through the cooling line when the cooling pump is driven; A cooling controller is configured to control the operating status of the cooling pump based on the temperature of the fuel cell or the temperature of the cooling medium; as well as A power generation controller is configured to limit the power generation of the fuel cell based on the operating state of the cooling pump; The power generation controller limits the power generation of the fuel cell based on the speed difference between the actual speed of the cooling pump and a reference speed set based on the temperature of the cooling medium or the fuel cell, or based on the power consumption difference between the actual power consumption of the cooling pump and a reference power consumption preset according to the speed of the cooling pump.

2. The system according to claim 1, wherein, The cooling pipes are equipped with radiators, which enable the cooling medium flowing along the cooling pipes to exchange heat with the outside air. The cooling pipes are connected such that the inlet and outlet of the fuel cell are in communication with the radiator, and The cooling pump causes some or all of the cooling medium discharged from the outlet of the fuel cell to flow to the radiator, or causes the cooling medium discharged from the radiator to flow into the inlet of the fuel cell.

3. The system of claim 1 further includes a temperature sensor configured to sense the temperature of the cooling medium flowing through the cooling conduit, the temperature sensor being mounted on the cooling conduit and located near the outlet of the fuel cell. in, The cooling controller controls the operating state of the cooling pump based on the temperature of the cooling medium sensed by the temperature sensor.

4. The system according to claim 1, wherein, The power generation controller limits the power generation of the fuel cell such that the amount of electricity generated by the fuel cell is equal to or less than a reference power generation set according to the temperature of the fuel cell or the cooling medium. The power generation controller applies a first offset value set based on the speed difference to the temperature of the fuel cell or the cooling medium or the reference power generation.

5. The system according to claim 4, wherein, When the speed difference has a value equal to or greater than a predetermined speed difference value, the power generation controller sets the first offset value such that as the speed difference increases, the temperature of the fuel cell or the cooling medium that limits the power generation of the fuel cell gradually decreases or the reference power generation gradually decreases.

6. The system according to claim 1, wherein, The power generation controller limits the power generation of the fuel cell based on the power consumption difference only when the actual speed of the cooling pump is equal to or higher than the preset reference speed.

7. The system according to claim 1, wherein, The power generation controller limits the power generation of the fuel cell so that the amount of electricity generated by the fuel cell is equal to or less than a preset reference power generation based on the temperature of the fuel cell or cooling medium. When the actual power consumption of the cooling pump is equal to or less than the reference power consumption, the power generation controller applies a second offset value set based on the power consumption difference to the temperature of the fuel cell or the cooling medium, or to the reference power generation.

8. The system according to claim 7, wherein, When the power consumption difference has a value equal to or greater than a predetermined power consumption difference value, the power generation controller sets the second offset value so that as the power consumption difference increases, the temperature of the fuel cell or the cooling medium that limits the power generation of the fuel cell gradually decreases or the reference power generation gradually decreases.

9. The system according to claim 1, wherein, When the actual power consumption of the cooling pump is higher than the reference power consumption, the cooling controller increases the cooling capacity of the cooling pump based on the power consumption difference.

10. A control method for preventing overheating of a fuel cell, the method comprising: Estimate the temperature of the fuel cell or sense the temperature of the cooling medium; The operating state of the cooling pump that circulates the cooling medium through the cooling pipe connected to the fuel cell is controlled based on the estimated temperature of the fuel cell or the sensed temperature of the cooling medium. as well as The power generation of the fuel cell is limited based on the operating state of the cooling pump; The power generation of the fuel cell is limited based on the speed difference between the actual speed of the cooling pump and a reference speed set based on the temperature of the cooling medium or the fuel cell, or based on the power consumption difference between the actual power consumption of the cooling pump and a reference power consumption preset according to the speed of the cooling pump.

11. The method according to claim 10, wherein, The power generation of the fuel cell is limited such that the power generation of the fuel cell is equal to or less than a reference power generation preset based on the temperature of the fuel cell or the cooling medium, and a first offset value set based on the speed difference is applied to the temperature of the fuel cell or the cooling medium or to the reference power generation.

12. The method according to claim 10, wherein, The power generation limitation is implemented such that the power generated by the fuel cell is limited to be equal to or less than a preset reference power generation based on the temperature of the fuel cell or the cooling medium, and such that when the actual power consumption of the cooling pump is equal to or lower than the reference power consumption, a second offset value set based on the power consumption difference is applied to the temperature of the fuel cell or the cooling medium or to the reference power generation.

13. The method of claim 10, further comprising increasing the cooling capacity of the cooling pump based on the power consumption difference when the actual power consumption of the cooling pump is greater than the reference power consumption, wherein, The increase in cooling capacity is performed after the power consumption difference has been calculated.

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