Multi-module fuel cell system and control method thereof

Abstract

The invention relates to a multi-module fuel cell system and a control method thereof. The multi-module fuel cell system includes: a plurality of fuel cell stacks; at least one cell connected to the plurality of fuel cell stacks; and a controller configured to determine whether to allow the plurality of fuel cell stacks and the at least one cell to provide the output in response to an input of the requested output, and selectively control the plurality of fuel cell stacks or the at least one cell to provide the output to satisfy the requested output based on a result of the determination regarding whether to allow the output to be provided.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a multi-module fuel cell system including a plurality of fuel cell stacks and a battery, selectively driving the fuel cell stacks and the battery to provide power to the outside, and a control method thereof, and the multi-module fuel cell system can be applied to an electric vehicle charging station. BACKGROUND

[0002] Recently, as the increase in popularity of electric vehicles (EVs), technologies for EV charging stations have been developed. The EV charging station needs to store a large amount of power or receive power from the outside. However, in practice, it takes a large amount of cost and infrastructure to build such a charging station.

[0003] As a countermeasure, a plan to utilize a fuel cell in an electric vehicle charging station has been considered. If a fuel cell is utilized in an electric vehicle charging station, hydrogen can be used as an energy storage source, which is very effective.

[0004] However, such a charging station equipped with a plurality of fuel cell stacks to charge an electric vehicle can have the following problems: the stacks are aged or the system can become unstable due to inefficient control of the fuel cell stacks.

[0005] The matters described above as background technical matters are intended to merely enhance understanding of the background of the present disclosure and should not be considered as admitting that the matters correspond to the conventional technologies known to those skilled in the art. SUMMARY

[0006] The following summary presents a simplified summary of some features. This summary is not an extensive overview and is not intended to identify key or critical elements.

[0007] A system, apparatus, and method for a multi-module fuel cell system are described. The multi-module fuel cell system can include a plurality of fuel cell stacks, at least one battery connected to the plurality of fuel cell stacks, and a controller configured to determine one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide a power output based on an input indicative of a requested power output and based on at least one of a state of charge (SoC) of the at least one battery and a number of fuel cell stacks in the plurality of fuel cell stacks, and selectively control at least one fuel cell stack in the plurality of fuel cell stacks or the at least one battery to output power to meet the requested power output based on the determined one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide the power output.

[0008] A method of controlling a multi-module fuel cell system including a plurality of fuel cell stacks and at least one battery can include: determining, by a controller of the multi-module fuel cell system, one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide an electrical power output based on an input indicative of the requested electrical power output and based on at least one of a state of charge (SoC) of the at least one battery and a number of fuel cell stacks in the plurality of fuel cell stacks; and selectively controlling, by the controller, at least one of the plurality of fuel cell stacks or the at least one battery to output electrical power to satisfy the requested electrical power output based on the determined one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide the electrical power output.

[0009] A multi-module fuel cell system can include: a plurality of fuel cell stacks; at least one battery; and a controller including: one or more processors; and a memory storing instructions that, when executed by the one or more processors, configure the controller to: monitor a state of charge (SoC) of the at least one battery and a cumulative amount of electrical power output of each fuel cell stack in the plurality of fuel cell stacks; receive a request for electrical power; and based on the request and whether the monitored SoC satisfies a SoC criterion, control: a fuel cell stack in the plurality of fuel cell stacks to satisfy the request based on a corresponding cumulative amount in the monitored cumulative amounts, or the at least one battery to satisfy the request.

[0010] A method of controlling a multi-module fuel cell system including a plurality of fuel cell stacks and at least one battery can include: monitoring a state of charge (SoC) of the at least one battery and a cumulative amount of electrical power output of each fuel cell stack in the plurality of fuel cell stacks; receiving a request for electrical power; and based on the request and whether the monitored SoC satisfies a SoC criterion, controlling: a fuel cell stack in the plurality of fuel cell stacks to satisfy the request based on a corresponding cumulative amount in the monitored cumulative amounts, or the at least one battery to satisfy the request.

[0011] These and other features and advantages will be described in more detail below. BRIEF DESCRIPTION OF DRAWINGS

[0012] The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0013] Figure 1 is a diagram illustrating a multi-module fuel cell system according to an example of the present disclosure;

[0014] Figure 2 is a flowchart for describing a method of controlling a multi-module fuel cell system according to an example of the present disclosure;

[0015] Figure 3 is a diagram for describing an output flow of a multi-module fuel cell system according to an example of the disclosure; and

[0016] Figure 4 is a diagram for describing a cell pre-charge of a multi-module fuel cell system according to an example of the disclosure. DETAILED DESCRIPTION

[0017] Hereinafter, examples of the disclosure will be described in detail with reference to the accompanying drawings. The same or similar components will be assigned the same reference numerals regardless of the reference numerals, and repetitive description thereof will be omitted.

[0018] If a detailed description of the related known technology can obscure the gist of the examples disclosed in the specification, a detailed description thereof will be omitted. Also, the accompanying drawings are only for easy understanding of the examples disclosed in the specification, and the technical idea disclosed in the specification is not limited by the accompanying drawings. Also, it should be understood that the disclosure encompasses all variations, equivalents, and alternatives included in the spirit and scope of the disclosure.

[0019] Although terms including ordinal numbers such as "first," "second," or the like can be used in this document to describe various components, the components are not limited by the terms. The terms are generally used only to distinguish one component from another.

[0020] Unless the context clearly indicates otherwise, the singular expression includes the plural form.

[0021] In the present specification, it should be understood that terms such as "include," "comprise," or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification and do not exclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0022] The suffix "module" and "unit" of the components used in the following description are given or used interchangeably only for the ease of preparation of the specification, and do not have a different meaning or role by themselves.

[0023] When a component is referred to as being "coupled" or "connected" to another component, the component can be directly coupled or connected to the other component. However, it should be understood that another component can exist therebetween. In contrast, when a component is referred to as being "directly coupled" or "directly connected" to another component, it should be understood that there is no other component therebetween.

[0024] The controller can include a communication device to communicate with other controllers or sensors to control functions allocated to the other controllers or sensors, a memory to store an operating system or logic commands, input / output information, etc., and one or more processors to perform determinations, calculations, decisions, etc. necessary to control functions allocated to the other controllers or sensors.

[0025] Figure 1 is a diagram illustrating a multi-module fuel cell system according to an example of the present disclosure, Figure 2 is a flowchart for describing a method of controlling a multi-module fuel cell system according to an example of the present disclosure, Figure 3 is a diagram for describing an output flow of a multi-module fuel cell system according to an example of the present disclosure, and Figure 4 is a diagram for describing a cell pre-charge of a multi-module fuel cell system according to an example of the present disclosure.

[0026] Referring to Figure 1 A multi-module fuel cell system according to an example of the present disclosure can include a plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4, at least one battery 300, and a controller 500. Figure 1 A configuration related to an example of the present disclosure is illustrated, and it should be understood that an actual multi-module fuel cell system can include more components. Also, or alternatively, while four fuel cell stacks 100-1, 100-2, 100-3, and 100-4 are illustrated and described in the example, the present disclosure includes any number of fuel cell stacks (e.g., any two or more fuel cell stacks).

[0027] For example, a multi-module fuel cell system according to an example of the present disclosure can be applied to an electric vehicle charging station, and can be applied to a factory or a building. Hereinafter, a case in which the multi-module fuel cell system is applied to an electric vehicle charging station will be described as a representative example.

[0028] A fuel cell system can be equipped with fuel cell stacks that generate electricity using hydrogen and air. The fuel cell stacks generate electrical energy via a chemical reaction, and use hydrogen as an energy source, such that it has an advantage of being able to respond adequately to a sudden power demand.

[0029] However, because the fuel cell stacks involve a chemical reaction, its durability is limited and the efficiency of the fuel cell stacks decreases during initial startup (e.g., each time it is started), such that optimal control of the durability and efficiency can need to be considered.

[0030] Accordingly, the multi-module fuel cell system of the present disclosure can be equipped with a plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4. Selectively operating the fuel cell stacks 100-1, 100-2, 100-3, and 100-4 according to the durability and / or the deterioration state (state of health (SoH)) of each fuel cell stack can enable management of the durability of each / all of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 (e.g., to improve or even maximize the durability).

[0031] In addition, the battery 300 can be arranged to be connected to one or more of the fuel cell stacks 100-1, 100-2, 100-3, and 100-4. The battery 300 can be charged via the connected plurality of fuel cell stacks, and the charge can be used to respond to a small required output, thereby preventing frequent start / stop of the fuel cell stacks. Accordingly, the battery 300 can need to be individually controlled (e.g., via the controller 500) according to the state of the battery 300 (e.g., the state of charge (SoC) and / or the temperature of the battery 300).

[0032] The controller 500 can control the power supply / supplied (e.g., to a vehicle including the multi-module fuel cell system) by controlling the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or the battery 300. For example, if the multi-module fuel cell system according to examples of the present disclosure is applied to an electric vehicle charging station, the controller 500 can provide power to the vehicle by controlling the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or the battery 300. The term "external" in the present disclosure means various components that request power from the outside of the system of the present disclosure, such as a charger, a vehicle, an electrical device of a building, etc.

[0033] The battery 300 according to examples of the present disclosure can refer to a battery that is charged and / or discharged at a high voltage. Although Figure 1 It is disclosed that only one battery 300 is provided, but this is only an example, and one or more batteries 300 can be provided.

[0034] The controller 500 can receive an input (e.g., from the outside) indicating a required output (where the "required output" can be a desired and / or requested output indicated by the input). The controller 500 can control one or more of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and the battery 300 based on the input to provide an output power to the outside. For example, the controller 500 can collect information about a state of each of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4, a state of the battery 300, and / or the input (e.g., indicating a desired / required / requested output). The controller 500 can control the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or the battery 300 to provide an output satisfying the input and taking into account / based on the state of each of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or the state of the battery 300. Also, or alternatively, the controller 500 can control only a subset (e.g., at least one fuel cell stack) of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or only the battery 300 to provide the output. Also, alternatively, the controller 500 can control the battery 300 to be charged using an output of at least one of the plurality of fuel cell stacks (e.g., as required).

[0035] The controller 500 according to examples of the present disclosure can determine whether the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or the at least one battery 300 can provide an output in response to the input (e.g., the required / desired output). The controller 500 can selectively control the plurality of fuel cell stacks 100-1, 100-2, 100-3, and / or 100-4 and / or the at least one battery 300 to provide the output to satisfy the required output based on a result of the determination as to whether the output can be provided, which will be described in detail with reference to Figure 2

[0036] Hereinafter, a method of controlling a multi-module fuel cell system according to examples of the present disclosure will be described with reference to Figure 2

[0037] Figure 2 is a flowchart for describing a method of controlling a multi-module fuel cell system according to examples of the present disclosure, and a multi-module fuel cell system according to examples of the present disclosure and a specific control thereof will be described with reference to Figure 2

[0038] ​​​An input indicating a required power output can be received (S201). Based on the required output inputted (S201) (e.g., from the outside), the controller 500 can determine whether the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and the at least one battery 300 can provide the output.

[0039] For example, the controller 500 can determine the SoC of the at least one battery 300, and compare the determined SoC of the at least one battery 300 with a first SoC preset to correspond to an upper limit of the battery SoC (S202). For example, the preset first SoC can be a value corresponding to 80% of the battery SoC. However, this is merely an example, and the present disclosure is not necessarily limited thereto. The controller 500 can determine whether the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and the at least one battery 300 can provide the output based on a comparison result between the SoC of the at least one battery 300 and the preset first SoC.

[0040] If the SoC of the at least one battery 300 exceeds the first SoC (Yes in S202), the controller 500 can determine whether the at least one battery 300 can provide the output (S204) based on the number of the at least one battery 300, the input, and at least one of the following: the available output information of the at least one battery 300, the temperature information of the at least one battery 300, and the SoC information of the at least one battery (S203). For example, the controller 500 can divide the required output by the battery available output, and compare the resulting value with the total number of the batteries equipped in the system (S203). The controller 500 can determine whether the at least one battery 300 can provide the output based on the comparison result (S204). The reason for performing such a determination process can be to determine whether to process the required output requested from the outside using only the batteries included in the system.

[0041] The controller 500 can receive (e.g., the controller equipped with data mapping receives) an input of a temperature (e.g., via a temperature sensor associated with the at least one battery 300) and / or an SoC of the at least one battery 300 (e.g., via an SoC sensor such as a voltmeter). The controller 500 can determine whether the output (power) can be provided via the battery 300 based on the input temperature and / or SoC. For example, the controller 500 can determine whether the battery can provide the output power. The controller 500 can determine whether the battery 300 can provide the output using the data mapping. In the data mapping, the current temperature and / or SoC of the battery 300 can be inputted, and a corresponding expected / predicted power from the battery 300 can be derived. The controller 500 can compare the derived power with the required output (e.g., indicated by the input in S201) to determine whether the battery 300 can provide the output.

[0042] If the SoC of at least one battery 300 is less than or equal to the first SoC (NO in S202), the controller 500 can determine whether the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can provide the output based on the first output according to the output level, the second output greater than the first output, the number of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4, and / or the required output (S205, S206, and S207). For example, the controller 500 can divide the required output by each of the first output and the second output greater than the first output, and compare each divided value with the number of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 provided in the system (S205 and S206). Then, the controller 500 can determine whether the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can provide the output based on the comparison result (S207).

[0043] The controller 500 can determine that the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can provide the output using the first output based on a value obtained by dividing the required output by the first output being less than or equal to the number of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4. The controller 500 can determine that the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can provide the output using the second output based on a value obtained by dividing the required output by the second output being less than or equal to the number of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4. The reason for performing such a determination process can be to determine the level at which the plurality of fuel cell stacks operates if the required output (indicated by the input / requested via the input) is processed by the plurality of fuel cell stacks provided in the system.

[0044] For example, in an example of the disclosure, the first output can be an intermediate level output within an output range of the required output (for example, the first output can be a value corresponding to 68 kW, which can represent an intermediate level), and the second output can be a high level output within the output range of the required output (for example, the second output can be a value corresponding to 80 kW, which can represent a high level). However, it should be understood that the above numerical values are merely examples, and the disclosure is not necessarily limited thereto. If it is determined that the first output is sufficient (S205), it can not be necessary to determine that the second output is sufficient (S206 can not be performed).

[0045] Subsequently, controller 500 can determine the usage priority of the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or at least one cell 300 (S208). The usage priority can be determined based on the determination of whether output can be provided (S204, S207). For example, controller 500 can determine, based on the determination of whether output can be provided, whether to first use at least one cell 300 and / or first use the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to meet the required output. Based on the determination that the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and at least one cell 300 can all provide output (e.g., are capable of providing sufficient output), controller 500 according to the example of this disclosure can determine the usage priority such that at least one cell 300 is used first before using the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4. Alternatively, the controller 500 may determine usage priorities such that at least one battery 300 is used first, and then multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 are used, but among the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4, the fuel cell stack that can provide output using the first output is preferred, and the fuel cell stack that can provide output using only the second output is used later (e.g., with a lower priority).

[0046] If the controller 500 determines the usage priority so that cell 300 is used first before multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4, unnecessary startup of the fuel cell stacks can be minimized / reduced, and inefficient operation of the fuel cell stacks due to low output demand can be minimized / reduced. Furthermore, or alternatively, by prioritizing the output among the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4, each fuel cell stack can achieve efficient output, thereby preventing / reducing / delaying the degradation of the fuel cell stack's durability.

[0047] The controller 500 can selectively control multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or at least one cell 300 to provide output to meet the required output, based on the determined usage priority. In the following, the control by the controller 500 will be described considering the determination results regarding whether the cell can provide output (S204) and / or the determination results regarding whether the fuel cell stack can provide output (S207).

[0048] For example, controller 500 can compare the required output with the dischargeable output of at least one battery 300 to determine whether the required output is less than or equal to the dischargeable output of at least one battery 300 (S209). If at least one battery 300 can provide output and the required output is less than or equal to the dischargeable output of the battery (Yes in S209), then controller 500 can control at least one battery 300 to provide output to meet the required output (S210). In this case, controller 500 can control multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 not to provide and / or suspend providing output. In this way, the durability of the fuel cell stacks can be ensured by reducing unnecessary operation of the fuel cell stacks, and / or a high level of energy efficiency can be achieved.

[0049] However, if at least one cell 300 cannot meet the required output, the operation of the fuel cell stack may be necessary.

[0050] For example, if the required output exceeds the dischargeable output of the battery even if at least one battery 300 can provide output (No in S209), the controller 500 can determine whether the required output is less than or equal to a third output based on the output level (S211), and perform a control operation based on the determination result. In this case, the third output based on the output level can represent an output lower than the first and second outputs described above. For example, the third value can be a low output level within the output range of the required output (e.g., a value corresponding to 30 kW as representing a low output level). However, this value is merely an example, and this disclosure is not necessarily limited to it.

[0051] If the required output is less than or equal to the third output (Yes in S211), the controller 500 can further determine the SoC of at least one battery 300 and control the plurality of fuel cell stacks 100-1, 100-2, 100-3, and 100-4 and / or at least one battery 300 to provide output. For example, if the required output is less than or equal to the third output (Yes in S211), it is determined that at least one battery 300 is capable of providing output (S204), and if the SoC of at least one battery 300 is greater than or equal to the second SoC (Yes in S212), the controller 500 can determine that the required output can be processed using only the battery. The controller 500 can control at least one battery 300 to provide output based on this determination (S210). The second SoC may be a value preset to correspond to a lower limit of the battery SoC. For example, the second SoC may be a value corresponding to 40% of the battery SoC. However, this is only an example, and the present disclosure is not necessarily limited thereto.

[0052] However, even if the required output is less than or equal to the third output (Yes in S211), it is difficult to process the required output using only at least one battery 300. For example, if the required output is less than or equal to the third output (Yes in S211), and the output of at least one battery 300 is unavailable, or the SoC of at least one battery 300 is less than the second SoC (No in S212), then the controller 500 can control multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to provide output (e.g., in this document, controlling one or more fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to provide one or more outputs). For example, the controller 500 can determine the total cumulative output of each of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4, and control the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to provide output in descending order of the determined total cumulative output (S213). Because the required output requested / input from the outside is a low output less than or equal to the third output, the performance required by the fuel cell stack (e.g., electrical output) may be very low. Therefore, in order to meet the required output by first using an aged fuel cell stack while maintaining the durability of the other fuel cell stacks, the controller 500 can determine the total cumulative output of each of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4, and control the supply of fuel cell stack outputs in descending order of total cumulative output. Total cumulative output refers to the total amount of energy generated by the fuel cell stack from the beginning to the present, and can be considered as SoH from a long-term perspective of the fuel cell stack. If the required output is low, a fuel cell stack with low SoH can be used to handle the required output, and in this way, the durability of fuel cell stacks with high SoH can be improved.

[0053] Alternatively, controller 500 can control multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to provide output to the outside and (e.g., simultaneously) charge at least one battery 300. By charging the battery and (e.g., simultaneously) maintaining the required output, the battery can provide output later, thereby reducing unnecessary startup of the fuel cell stack, improving the durability of the fuel cell stack, and achieving energy efficiency.

[0054] Simultaneously, if the required output exceeds the third output, which is the lowest output, the controller 500 can use different strategies to control the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4. For example, if the required output exceeds the third output (No in S211), the controller 500 can determine the SoC of at least one cell 300 and the cumulative output of each of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 (e.g., after startup). Furthermore, or alternatively, if the SoC of at least one cell is greater than or equal to a first SoC preset to correspond to the upper limit of the cell SoC and the sum of the cumulative outputs of each of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 after startup is greater than or equal to a preset reference cumulative output (Yes in S214), the controller 500 can control at least one cell 300 to provide output (S215). Alternatively, controller 500 can control multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to suspend output from the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4. In this case, the cumulative output after the fuel cell stacks start up can represent the short-term performance of cumulative power generation from the last start-up time. Therefore, power is supplied to the outside in a limited manner only when the output required externally exceeds the third output, which is a low output, the battery's SoC is sufficient, and the fatigue of the fuel cell stacks accumulates in a short period of time.

[0055] Therefore, even if a large output is required from the outside (e.g., by an attached load for receiving power) (e.g., indicated by inputs, requests, etc.), only battery 300 is used to provide power because the SoC of battery 300 is sufficient, and the operation of multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 is suspended, thereby reducing unnecessary operation of fuel cell stacks, which ensures the durability of fuel cell stacks and achieves a high level of energy efficiency.

[0056] If the output of at least one cell 300 is unavailable (e.g., insufficient), the SoC of at least one cell 300 is less than the first SoC, or the sum of the cumulative outputs after each of the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 is less than the reference cumulative output (No in S214), then the controller 500 may control the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 to provide output. For example, controller 500 can determine the cumulative output of each of the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 (e.g., after startup), or the total cumulative output of each of the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4, and control the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 to provide output in ascending order of cumulative output after startup or total cumulative output (S216).

[0057] Due to insufficient SoC of battery 300 or the expected good short-term condition of the fuel cell stack, the required output can be provided to the outside via multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4. Alternatively, if only some of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 need to be operated, controller 500 can select and operate one or more fuel cell stacks with the minimum cumulative output. That is, by selecting and using fuel cell stacks with good short-term SoH, the overall durability performance of the fuel cell stacks can be maintained. If multiple fuel cell stacks with optimal short-term SoH exist, the fuel cell stack with the smaller total cumulative output can be operated first to provide output to the outside. In other words, by prioritizing short-term performance and using fuel cell stacks with good long-term performance first when short-term performance is comparable, the durability performance of multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can be balanced.

[0058] Alternatively, the controller 500 may use the outputs of multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 to provide output to the outside while simultaneously charging at least one battery 300. In this way, by maintaining the required output while charging the battery, the battery can provide output later, reducing unnecessary startup of the fuel cell stack, thereby ensuring the durability of the fuel cell stack and achieving energy efficiency.

[0059] The controller 500 can control multiple fuel cell stacks 100-1, 100-2, 100-3 and / or 100-4 and / or at least one cell 300 to provide output to the outside according to the control strategy determined as described herein. The controller can also (e.g., simultaneously) monitor (e.g., continuously and / or semi-continuously / periodically) the state of the multiple fuel cell stacks 100-1, 100-2, 100-3 and 100-4 and / or at least one cell 300 (e.g., in real time and / or while controlling them) (S217). The controller 500 can re-examine the control strategy by re-determining usage priorities based on monitoring (e.g., in real time or periodically based on monitoring results).

[0060] In the following text, reference will be made to Figure 3 and Figure 4 The state changes of the fuel cell stack and cells are described using a multi-module fuel cell system and its control method according to examples of this disclosure.

[0061] Figure 3 This is a diagram illustrating the output flow of a multi-module fuel cell system according to an example of this disclosure, and Figure 4 This is a diagram illustrating the pre-charging of a battery in a multi-module fuel cell system according to an example of this disclosure.

[0062] Figure 3 An example is shown where, at the beginning of time period A, the SoC of battery 300 is less than the second SoC (SoC 2). SoC 2 is the lower limit of the SoC of battery 300. Therefore, in period A, since the SoC of battery 300 is lower than the second SoC (SoC 2) which is the lower limit, the first fuel cell stack 100-1 of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4 can generate electricity. The first fuel cell stack 100-1 can generate an output P1 to meet the needs of external input, and can use the output of P1 to provide output to the outside while simultaneously charging battery 300. Therefore, the SoC of battery 300 can gradually increase in period A.

[0063] Alternatively, in section B, even if the SoC of battery 300 is greater than the second SoC (SoC 2), which is the lower limit of the SoC, it may still be difficult to meet the external output requirements using only battery 300 (e.g., no in S214), and therefore output may continue to be provided via one or more of the multiple fuel cell stacks 100-1, 100-2, 100-3, and 100-4. However, to balance the durability performance among the fuel cell stacks, a control operation can be performed to make the second fuel cell stack 100-2 generate electricity and to suspend the first fuel cell stack 100-1 from generating electricity. Subsequently, in section C, the first fuel cell stack 100-1 can be restarted and the second fuel cell stack 100-2 can be suspended from generating electricity.

[0064] Through sections A to C, battery 300 can be charged by receiving output from the fuel cell stack, and the SoC of battery 300 can reach the first SoC (SoC 1), which is the upper limit of the SoC.

[0065] If the SoC of battery 300 reaches the first SoC (SoC 1), power generation from all fuel cell stacks can be suspended and output can be provided to the outside using only battery 300 (e.g., as in S214). In this way, the durability of the fuel cell stack can be ensured. As shown in section D, controller 500 can control the output to provide the required output using only battery 300 until the SoC of battery 300 reaches the second SoC (SoC 2).

[0066] If the SoC of battery 300 reaches the second SoC (SoC 2) as the lower limit, then the first fuel cell stack 100-1 and / or the second fuel cell stack 100-2 can generate electricity sequentially as in segments E and F. Figure 3 The diagram shows the second fuel cell stack 100-2 generating power first, followed by the first fuel cell stack 100-1. However, this is merely an example, and the disclosure is not necessarily limited thereto. The first fuel cell stack 100-1 may generate power first, and the second fuel cell stack 100-2 may generate power later. Furthermore, or alternatively, if the SoC of battery 300 again reaches the first SoC (SoC 1) as in section G, then power supply to the outside is accomplished using battery 300. However, depending on the characteristics of the required output requested from the outside, the output P2 of battery 300 may be lower than the initial output P1 of battery 300.

[0067] Alternatively, for battery 300, the output may correspond to performance related to SoC and / or temperature. Therefore, in order to deliver the desired output via battery 300, the SoC and temperature conditions of battery 300 must first be met.

[0068] Therefore, such as Figure 4 As shown, by predicting how the required output changes over time, the SoC of battery 300 can be increased (e.g., before the predicted high output requirement), such as from segment H before segment J where high output is required. By increasing the SoC of battery 300 in advance (e.g., before the need / request for high output), the temperature of battery 300 can be increased in advance, and the required output can be provided using only battery 300 from segment J where high output is required without difficulty.

[0069] This disclosure is made to address various problems in the prior art. This disclosure provides a multi-module fuel cell system and its control method, which extends the lifespan of the fuel cell stack and achieves efficient charging management by effectively controlling multiple fuel cell stacks and cells.

[0070] A multi-module fuel cell system may include multiple fuel cell stacks, at least one cell connected to the multiple fuel cell stacks, and a controller configured to determine whether the multiple fuel cell stacks and at least one cell are allowed to provide output in response to a desired output input. Based on the determination of whether output provision is permitted, the controller may selectively control the multiple fuel cell stacks and / or at least one cell to provide output to meet the desired output.

[0071] Alternatively, a method for controlling a multi-module fuel cell system configured to provide output through multiple fuel cell stacks and at least one cell may include: determining whether the multiple fuel cell stacks and at least one cell are allowed to provide output by means of an input from a controller in response to a desired output, and selectively controlling the multiple fuel cell stacks or at least one cell to provide output to meet the desired output by means of the controller based on the determination result regarding whether output is allowed.

[0072] The multi-module fuel cell system and control method disclosed herein can extend / increase the lifespan of the fuel cell stack and effectively manage charging by effectively controlling the fuel cell stack and cells.

[0073] The durability of a fuel cell stack can be improved by evenly distributing the usage time of each module in the fuel cell system and by minimizing unnecessary startups of the fuel cell stack due to prioritizing battery output if low output is required.

[0074] Alternatively, if low output is required, efficient energy management can be achieved by prioritizing charging / discharging after the battery temperature rises and minimizing the inefficient operating sections of the fuel cell stack.

[0075] Although the present disclosure has been illustrated and described with respect to specific examples, it will be apparent to those skilled in the art that various improvements and modifications may be made to the present disclosure without departing from the technical spirit of the disclosure as defined by the appended claims.

[0076] Furthermore, the term "control device," "control unit," "control apparatus," "control module," or "server," etc., refers to a hardware device including a memory and a processor configured to execute one or more steps interpreted as an algorithmic structure. The memory stores the algorithmic steps, and the processor executes the algorithmic steps to perform one or more processes of the methods according to various examples of this disclosure. The control device according to examples of this disclosure can be implemented using non-volatile memory and a processor, the non-volatile memory being configured to store algorithms for controlling the operation of various components of a vehicle or data regarding software commands for executing the algorithms, and the processor being configured to perform the aforementioned operations using the data stored in the memory. The memory and processor can be separate chips. Alternatively, the memory and processor can be integrated into a single chip. The processor can be implemented as one or more processors. The processor can include various logic circuits and operational circuits, can be configured to process data according to a program provided from the memory, and can be configured to generate control signals based on the processing results.

[0077] The control device may be at least one microprocessor operated by a predetermined program, which may include a series of commands for performing the methods included in the various examples of this disclosure above.

[0078] The above disclosure can also be embodied in computer-readable code on a computer-readable recording medium. A computer-readable recording medium is any data storage device that can store data that can subsequently be read by a computer system and store and execute program instructions that can subsequently be read by a computer system. Examples of computer-readable recording media include hard disk drives (HDDs), solid-state drives (SSDs), silicon disk drives (SDDs), read-only memory (ROM), random access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and implementations as carrier waves (e.g., transmission over the Internet). Examples of program instructions include machine language code (such as machine language code generated by a compiler) and high-level language code that can be executed by a computer using an interpreter, etc.

[0079] In the various examples of this disclosure, each of the above operations can be performed by a control device, and the control device can be configured by multiple control devices or a single integrated control device.

[0080] In the various examples disclosed herein, the memory and processor may be provided as a single chip or as separate chips.

[0081] In various examples of this disclosure, the scope of this disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) for enabling operations according to the methods of various examples to be executed on a device or computer, including non-transitory computer-readable media storing and executable such software or commands on a device or computer.

[0082] In various examples of this disclosure, the control device may be implemented in hardware or software, or in a combination of hardware and software.

[0083] In addition, terms such as “unit” and “module” included in the specification refer to a unit for performing at least one function or operation, which can be implemented by hardware, software or a combination of hardware and software.

[0084] For ease of description and precise definition in the appended claims, the terms “above,” “below,” “inside,” “outside,” “on,” “below,” “upward,” “downward,” “in front,” “behind,” “behind,” “inside,” “outside,” “inward,” “outside,” “inner,” “outer,” “forward,” and “backward” are used to describe the features of the examples with reference to the position of such features as shown in the accompanying drawings. It should also be understood that the term “connection” or its derivatives refer to both direct and indirect connections.

[0085] The term “and / or” can include a combination of multiple related listed items or any multiple related listed items. For example, “A and / or B” includes all three cases, such as “A”, “B”, and “A and B”.

[0086] In this specification, unless otherwise stated, singular expressions include plural expressions, unless the context clearly indicates otherwise.

[0087] In the examples of this disclosure, "at least one of A and B" can refer to "at least one of A or B" or "at least one of a combination of one or more of A and B". Furthermore, "one or more of A and B" can refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0088] In the examples of this disclosure, it should be understood that terms such as “comprising” or “having” are intended to specify the presence of the features, numbers, steps, operations, elements, parts or combinations thereof described in the specification, and do not preclude the possibility of adding or having one or more other features, numbers, steps, operations, elements, parts or combinations thereof.

[0089] For purposes of illustration and description, the foregoing description of specific examples of this disclosure has been presented. They are not intended to be exhaustive or to limit this disclosure to the precise forms disclosed, and it will be apparent that many modifications and variations are possible in accordance with the foregoing teachings. Examples have been selected and described to illustrate some principles of this disclosure and its practical application, enabling others skilled in the art to implement and utilize various examples of this disclosure and their various alternatives and modifications. The scope of this disclosure is intended to be defined by the appended claims and their equivalents.

Claims

1. A multi-module fuel cell system comprising: a plurality of fuel cell stacks; at least one battery connected to the plurality of fuel cell stacks; and a controller configured to: determine one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide an electric power output based on an input indicative of a requested electric power output and based on at least one of a state of charge of the at least one battery and a number of fuel cell stacks in the plurality of fuel cell stacks, and selectively control at least one fuel cell stack in the plurality of fuel cell stacks or the at least one battery to output electric power to meet the requested electric power output based on the determined one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide the electric power output. The controller is further configured to:

2. The multi-module fuel cell system of claim 1, wherein, compare the state of charge of the at least one battery to a first state of charge preset to correspond to an upper limit of a battery state of charge based on the input; and determine the one or more of the plurality of fuel cell stacks and the at least one battery that are allowed to provide the electric power output based on the comparison. The controller is configured to determine whether the at least one battery is allowed to provide the electric power output based on the state of charge of the at least one battery exceeding the first state of charge, wherein the determination of whether the at least one battery is allowed to provide the electric power output is based on:

3. The multi-module fuel cell system of claim 2, wherein, a number of the at least one battery, the requested electric power output, and at least one of: available output information of the at least one battery, temperature information of the at least one battery, and state of charge information of the at least one battery. The controller is configured to determine whether the plurality of fuel cell stacks is allowed to provide the electric power output based on the state of charge of the at least one battery being less than or equal to the first state of charge, wherein the determination of whether the plurality of fuel cell stacks is allowed to provide the electric power output is based on:

4. The multi-module fuel cell system of claim 3, wherein, a first output according to an output level, a second output greater than the first output, a number of the plurality of fuel cell stacks, and the requested electric power output. The controller is configured to:

5. The multi-module fuel cell system of claim 4, wherein, determine that the plurality of fuel cell stacks is allowed to provide the electric power output using the first output based on a value obtained by dividing the requested electric power output by the first output being less than or equal to the number of the plurality of fuel cell stacks; and determine that the plurality of fuel cell stacks is allowed to provide the electric power output using the second output based on a value obtained by dividing the requested electric power output by the second output being less than or equal to the number of the plurality of fuel cell stacks. The controller is configured to: determine a usage priority of the plurality of fuel cell stacks and the at least one battery based on the determined one or more of the plurality of fuel cell stacks and the at least one battery, and 6. The multi-module fuel cell system of claim 1, wherein, selectively control the plurality of fuel cell stacks or the at least one battery to meet the requested electric power output based on the determined usage priority. The controller is configured to: ​ ​ 7. The multi-module fuel cell system of claim 1, wherein, ​ determining whether the requested power output is less than or equal to a dischargeable output available from the at least one battery; and controlling the at least one battery to output power to meet the requested power output based on a determination that the at least one battery is allowed to provide power output and based on the requested power output being less than or equal to the dischargeable output.

8. The multi-module fuel cell system of claim 1, wherein, the controller is configured to: determine whether the requested power output is less than or equal to a third output associated with an output level based on a determination that the at least one battery is allowed to provide power output and based on the requested power output exceeding the dischargeable output available from the at least one battery; and determine the state of charge of the at least one battery based on the requested power output being less than or equal to the third output.

9. The multi-module fuel cell system of claim 8, wherein, the controller is configured to control the at least one battery to output power based on the requested power output being less than or equal to the third output and based on the state of charge of the at least one battery being greater than or equal to a second state of charge preset to correspond to a lower limit of a battery state of charge.

10. The multi-module fuel cell system of claim 8, wherein, the controller is configured to: determine a total cumulative output amount of each fuel cell stack of the plurality of fuel cell stacks based on the requested power output being less than or equal to the third output and based on either the output of the at least one battery being unavailable or the state of charge of the at least one battery being less than a second state of charge preset to correspond to a lower limit of a battery state of charge, and control the plurality of fuel cell stacks to provide power output in a descending order of the determined total cumulative output amount.

11. The multi-module fuel cell system of claim 8, wherein, the controller is configured to: determine the state of charge of the at least one battery and a cumulative output amount of the plurality of fuel cell stacks based on the requested power output exceeding the third output; and control the at least one battery to output power based on the state of charge of the at least one battery being greater than or equal to a first state of charge preset to correspond to an upper limit of a battery state of charge and based on a sum of the cumulative output amount of the plurality of fuel cell stacks being greater than or equal to a preset reference cumulative output amount.

12. The multi-module fuel cell system of claim 8, wherein, the controller is configured to control the plurality of fuel cell stacks to output power in an ascending order of a cumulative output amount of each fuel cell stack of the plurality of fuel cell stacks after starting the plurality of fuel cell stacks or in an ascending order of a total cumulative output amount of each fuel cell stack of the plurality of fuel cell stacks based on at least one of: the output of the at least one battery being unavailable, the state of charge of the at least one battery being less than a first state of charge preset to correspond to an upper limit of a battery state of charge, and a sum of the cumulative output amount of the plurality of fuel cell stacks being less than a preset reference cumulative output amount.

13. A method of controlling a multi-module fuel cell system including a plurality of fuel cell stacks and at least one battery, the method comprising: determining, by a controller of the multi-module fuel cell system, one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide an electrical power output based on an input indicative of a requested electrical power output and based on at least one of a state of charge of the at least one battery and a number of fuel cell stacks of the plurality of fuel cell stacks; and selectively controlling, by the controller, at least one fuel cell stack of the plurality of fuel cell stacks or the at least one battery to output electrical power to satisfy the requested electrical power output based on the determined one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide the electrical power output.

14. The method of claim 13, wherein, The determining of the one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide the electrical power output is further based on: comparing, by the controller, the state of charge of the at least one battery to a first state of charge preset to correspond to an upper limit of a battery state of charge.

15. The method of claim 13, wherein, The determining of the one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide the electrical power output is further based on a number of the at least one battery, the requested electrical power output, and at least one of: available output information of the at least one battery, temperature information of the at least one battery, and state of charge information of the at least one battery based on the state of charge of the at least one battery being more than the first state of charge corresponding to an upper limit of a battery state of charge.

16. The method of claim 13, wherein, The determining of the one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide the electrical power output is further based on a first output according to an output level, a second output greater than the first output, a number of the plurality of fuel cell stacks, and the requested electrical power output based on the state of charge of the at least one battery being less than or equal to the first state of charge corresponding to an upper limit of a battery state of charge.

17. The method of claim 13, wherein, The selectively controlling is based on a use priority of the plurality of fuel cell stacks and the at least one battery determined by the controller based on the determined one or more of the plurality of fuel cell stacks and the at least one battery to allow to provide the electrical power output.

18. A multi-module fuel cell system, comprising: a plurality of fuel cell stacks; at least one battery; and a controller comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, configure the controller to: monitor: a state of charge of the at least one battery; and an accumulated amount of electrical power output of each fuel cell stack of the plurality of fuel cell stacks; receive a request for electrical power; and based on the request and whether the monitored state of charge satisfies a state of charge criterion, control: a fuel cell stack of the plurality of fuel cell stacks to satisfy the request based on a corresponding accumulated amount of the monitored accumulated amount; or the at least one battery to satisfy the request. ​ 19. The multi-module fuel cell system of claim 18, wherein, The instructions, when executed by the one or more processors, configure the controller to control the fuel cell stack of the plurality of fuel cell stacks to meet the request and control one or more fuel cell stacks of the plurality of fuel cell stacks to charge the at least one battery based on the monitored state of charge not meeting the state of charge criteria.

20. The multi-module fuel cell system of claim 18, wherein, The instructions, when executed by the one or more processors, configure the controller to determine a usage priority of the plurality of fuel cell stacks based on the cumulative amount, and wherein the plurality of fuel cell stacks are controlled based on the usage priority.

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