Fuel cell control system, fuel cell control method, and electrochemical detection device
The fuel cell control system uses electrochemical analysis to accurately manage water content, enhancing power output and lifespan by dynamically adjusting fuel state.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DELTA ELECTRONICS INC(CN)
- Filing Date
- 2025-01-23
- Publication Date
- 2026-07-23
Smart Images
Figure 2026524583000001_ABST
Abstract
Description
[Technical Field]
[0001] This disclosure relates to control technology for relevant parameters of fuel cell systems, and more particularly to a fuel cell control system, a fuel cell control method, and an electrochemical detection device capable of detecting the water content of a fuel cell and adjusting related parameters. [Background technology]
[0002] In current fuel cell technology, since fuel cells generate electric current using fuel (i.e., reaction gas), most commercially available fuel cell systems control the magnitude of the current by adjusting the amount of fuel. The performance of a fuel cell is related to its water content; if the water content of the fuel cell becomes unbalanced, the output power of the fuel cell decreases and its lifespan is shortened. To ensure that a fuel cell operates normally, it controls the fuel to maintain a normal water content in the membrane electrode assembly (membrane material). [Overview of the Initiative] [Problems that the invention aims to solve]
[0003] Currently available fuel cells typically use voltage detectors to monitor the voltage of each fuel cell and determine whether the water content of the fuel cells is unbalanced. However, this method cannot accurately determine the water content of the fuel cells and also affects the efficiency of fuel adjustment. Therefore, how to efficiently adjust the fuel based on the water content of the fuel cells in real time is one of the challenges in this field. [Means for solving the problem]
[0004] This disclosure provides a fuel cell control system. The fuel cell control system includes an electrochemical detector, a control device, and a power converter, which are connected to a fuel cell and used to supply power to a load. The electrochemical detector is connected to the fuel cell and includes a sensor device and a processor. The sensor device is used to detect the battery current and battery voltage of the fuel cell. The processor is connected to the sensor device and is used to perform electrochemical analysis based on the battery voltage and battery current and to determine the moisture state of the fuel cell based on the electrochemical analysis. The control device is connected to the fuel cell and the electrochemical detector and is used to adjust the fuel state of the fuel cell when the moisture state of the fuel cell is dry or flooded. The power converter is used to determine the load conditions of the fuel cell and, when the moisture state of the fuel cell is normal, to generate an output power based on the battery voltage and battery current, provided that the battery voltage and battery current are related to the load conditions.
[0005] This disclosure provides a fuel cell control method applicable to a fuel cell control system. The fuel cell control method includes the steps of: determining the load conditions of the fuel cell using a power converter; generating a battery voltage and battery current using the fuel cell based on the load conditions and the fuel state of the fuel cell; detecting the battery voltage and battery current using a sensor device; determining the moisture content of the fuel cell by performing electrochemical analysis based on the battery voltage and battery current using a processor; adjusting the fuel state of the fuel cell using a control device if the moisture content of the fuel cell is in a dry or flooded state; and generating an output power supply using a power converter based on the battery voltage and battery current if the moisture content of the fuel cell is in a normal state.
[0006] This disclosure provides an electrochemical detection device connected to a fuel cell. The electrochemical detection device includes a sensor device and a processor. The sensor device is used to detect the battery current and battery voltage generated by the fuel cell based on the fuel state. The processor is connected to the sensor device and is used to perform electrochemical analysis based on the battery voltage and battery current, and to determine whether the water content state of the fuel cell is normal, dry, or flooded based on the electrochemical analysis. [Effects of the Invention]
[0007] Through the fuel cell control system, fuel cell control method, and electrochemical detection device disclosed herein, it is possible to determine whether the water content of the fuel cell is normal using electrochemical analysis and adjust the fuel state of the fuel cell based on the analysis results, thereby effectively avoiding imbalances in the water content of the fuel cell. [Brief explanation of the drawing]
[0008] To make the above and other purposes, features, advantages, and examples of this disclosure clearer and easier to understand, the accompanying drawings are described below. [Figure 1] This is a schematic diagram showing the change in battery voltage over time using several real-world examples of fuel cells. [Figure 2] This is a functional block diagram of a fuel cell control system according to some embodiments of the present disclosure. [Figure 3] Figure 2 is a functional block diagram of a fuel cell according to an embodiment. [Figure 4] These are electrochemical impedance spectra of fuel cells according to some embodiments of the present disclosure. [Figure 5] This is a high-frequency resistance plot of a fuel cell according to some embodiments of the present disclosure. [Figure 6A] This is a flow diagram of a fuel cell control method according to some embodiments of the present disclosure. [Figure 6B] This is a flow diagram of some steps of a fuel cell control method according to some embodiments of the present disclosure. [Figure 6C]It is a flowchart of some steps of a fuel cell control method according to some embodiments of the present disclosure. [Figure 6D] It is a flowchart of some steps of a fuel cell control method according to some embodiments of the present disclosure. **Embodiments for Carrying Out the Invention**
[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar elements or method flows.
[0010] Unless otherwise specifically limited in the text, "a" and "the" can refer to a single or a plurality collectively. Further understood, the terms "including", "comprising", "having" and similar terms used in the text specify the described features, regions, integers, steps, operations, elements and / or components, but do not exclude one or more other described or additional features, regions, integers, steps, operations, elements, components and / or groups thereof.
[0011] FIG. 1 is a schematic diagram showing the change of the battery voltage V of a fuel cell over time according to some embodiments. As shown in the upper half of FIG. 1, as the usage time of the fuel cell increases, a change occurs in the relationship between the battery voltage V of the fuel cell FC and the battery current I. Specifically, as shown in the lower half of FIG. 1, under the condition of the same battery current I FC and the battery current I FC (for example, the battery current I corresponding to the vertical line in the upper half of FIG. 1 FC ), the battery voltage V of the fuel cell FC ) decreases with the increase of the usage time, and further deteriorates (decays) the power generation ability of the fuel cell. FC Such undesirable deterioration occurs in the fuel cell with the usage time, but by good management of the water content state (also called "water management"), the deterioration rate of the fuel cell can be slowed down. In order to effectively manage the water content state of the fuel cell, the present disclosure provides a fuel cell control system.
[0012]
[0013] Figure 2 is a functional block diagram of a fuel cell control system 100 according to some embodiments of the present disclosure. In some embodiments, the fuel cell control system 100 includes an electrochemical detector 120, a control device 130, and a power converter 140, which are used to supply power to a system load 150 via a fuel cell 110.
[0014] The fuel cell 110 is connected to an electrochemical detector 120, a control device 130, and a power converter 140, and the battery voltage V is controlled according to the load conditions set by the power converter 140 and the fuel state of the fuel cell 110. FC and battery current I FC It is used to generate [something]. In some embodiments, the fuel state of the fuel cell 110 includes the temperature state, air supply state, and hydrogen gas supply state of the fuel cell 110. As the temperature state, air supply state, and hydrogen gas supply state differ, the fuel cell 110 has different water content and thus different water content states.
[0015] Specifically, if the moisture content of the membrane electrode assembly within the fuel cell 110 is lower than the ideal value, the moisture state of the fuel cell 110 is called the "dry" state. If the moisture content of the membrane electrode assembly within the fuel cell 110 exceeds this ideal value, the moisture state of the fuel cell 110 is called the "flooding" state. If the moisture content of the membrane electrode assembly within the fuel cell 110 is equal to this ideal value, the moisture state of the fuel cell 110 is called the "normal" state. The method for determining the moisture content of the fuel cell 110 will be explained in detail in a later paragraph.
[0016] In some embodiments, the fuel cell 110 includes a subsystem for controlling the aforementioned fuel state. Refer to FIG. 3. FIG. 3 is a functional block diagram of the fuel cell 110 according to the embodiment of FIG. 2. In some embodiments, the fuel cell 110 includes a battery stack 111, a temperature control subsystem 112, an air conditioning subsystem 113, and a hydrogen regulation subsystem 114. The temperature control subsystem 112, the air conditioning subsystem 113, and the hydrogen regulation subsystem 114 are connected to the battery stack 111, and when receiving an adjustment command AD from the control device 130, they respectively adjust the temperature state, the air supply state, and the hydrogen gas supply state of the fuel cell 110, so that the fuel cell 110 generates a corresponding battery voltage V FC and a battery current I FC to generate.
[0017] Again, refer to FIG. 2. The electrochemical detection device 120 is connected to the fuel cell 110, the control device 130, and the power converter 140, and is used to perform an electrochemical analysis on the fuel cell 110. In some embodiments, the electrochemical detection device 120 includes a sensor device 121 and a processor 122.
[0018] The sensor device 121 is connected to the fuel cell 110 and is used to detect the battery voltage V FC and the battery current I FC of the fuel cell 110. Although the sensor device 121 in FIG. 2 is illustrated as a single block, it should be noted that the sensor device 121 is not limited to being realized by one device. In some embodiments, the sensor device 121 may be realized by a combination of electronic devices (for example, a voltage array measuring instrument and an ammeter) having two or more detection functions.
[0019] In some embodiments, the sensor device 121 detects the battery voltage V FC and the battery current I FCThe battery voltage V of the fuel cell 110 may be detected once, thereby enabling automation of the adjustment (also called activation). In some other embodiments, the sensor device 121 also detects the battery voltage V of the fuel cell 110 when it receives an adjustment command (e.g., from the processor 122). FC and battery current I FC It is permissible to detect this.
[0020] The processor 122 is connected to the sensor device 121, and the battery voltage V detected by the sensor device 121 FC and battery current I FC Based on this, electrochemical analysis is performed, and the water content of the fuel cell 110 is determined based on the results of the electrochemical analysis.
[0021] In some embodiments, the electrochemical analysis performed by the processor 122 is carried out by generating and analyzing an electrochemical impedance spectrum (EIS). See Figure 4. Figure 4 shows the electrochemical impedance spectrum 110_EIS of a fuel cell 110 according to some embodiments of the present disclosure, where the horizontal axis represents the real part Z' of the impedance of the fuel cell 110 and the vertical axis represents the imaginary part Z'' of the impedance of the fuel cell 110.
[0022] First, the processor 122 calculates an ideal electrochemical impedance spectrum (for example, the curve labeled "normal state" in Figure 4) based on the load conditions set by the power converter 140, and the battery voltage V detected by the sensor device 121 FC and battery current I FC The measured electrochemical impedance spectrum is calculated based on this. Those skilled in the art should understand how to generate the “electrochemical impedance spectrum” as referred to in this disclosure, and for the sake of brevity, this will not be repeated here.
[0023] In some embodiments, the processor 122 can determine the current moisture state of the fuel cell 110 by comparing the area enclosed by the shapes of the ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum. If the area enclosed by the shape corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is larger than the area enclosed by the shape corresponding to the normal state, the processor 122 determines that the moisture state of the fuel cell 110 is dry. If the area enclosed by the shape corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is smaller than the area enclosed by the shape corresponding to the normal state, the processor 122 determines that the moisture state of the fuel cell 110 is flooded.
[0024] In some other embodiments, the processor 122 can determine the current moisture state of the fuel cell 110 by comparing the figure peak values of an ideal electrochemical impedance spectrum with those of a measured electrochemical impedance spectrum. If the figure peak value corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is greater than the figure peak value corresponding to the normal state, the processor 122 determines that the moisture state of the fuel cell 110 is dry. If the figure peak value corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is smaller than the figure peak value corresponding to the normal state, the processor 122 determines that the moisture state of the fuel cell 110 is flooded.
[0025] In some other embodiments, the processor 122 can determine the current moisture state of the fuel cell 110 based on the trend of the geometric curve of the measured electrochemical impedance spectrum. If the geometric curve corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is a divergent curve, the processor 122 determines that the moisture state of the fuel cell 110 is dry. If the geometric curve corresponding to the current moisture state in the electrochemical impedance spectrum 110_EIS is a convergent curve, the processor 122 determines that the moisture state of the fuel cell 110 is flooded.
[0026] Furthermore, the processor 122 can also determine the current water content of the fuel cell 110 by combining the aforementioned determination methods. For example, the processor 122 can determine the water content of the fuel cell 110 based on both the area enclosed by the electrochemical impedance spectrum shape and the shape peak value.
[0027] It should be noted that the electrochemical analysis referred to in this disclosure is not limited to generating an electrochemical impedance spectrum. In some embodiments, the electrochemical analysis performed by processor 122 is performed by generating and analyzing a high-frequency resistance (HFR) plot. See Figure 5. Figure 5 is a high-frequency resistance plot 110_HFR of a fuel cell 110 according to some embodiments of this disclosure, where the vertical axis shows the resistance value of the fuel cell 110.
[0028] First, the processor 122 calculates an ideal high-frequency resistance plot (for example, the curve labeled "normal state" in Figure 5) based on the load conditions set by the power converter 140, and the battery voltage V detected by the sensor device 121 FC and battery current I FC A measured high-frequency resistance plot is calculated based on this. Those skilled in the art should understand how to generate the “high-frequency resistance plot” as referred to in this disclosure, and for the sake of brevity, this will not be repeated here.
[0029] Next, the processor 122 can determine the current moisture content of the fuel cell 110 by comparing a reference high-frequency resistance plot with the measured high-frequency resistance plot. At the same time point, if the resistance value of the curve corresponding to the current moisture content in the high-frequency resistance plot 110_HFR is greater than the resistance value of the curve corresponding to the normal state, the processor 122 determines that the moisture content of the fuel cell 110 is in a dry state. If the resistance value of the curve corresponding to the current moisture content in the high-frequency resistance plot 110_HFR is less than the resistance value of the curve corresponding to the normal state, the processor 122 determines that the moisture content of the fuel cell 110 is in a flooded state.
[0030] In some embodiments, the processor 122 is also used to determine whether the system load of the fuel cell control system 100 is stable. If the system load of the fuel cell control system 100 is not yet stable, the processor 122 waits for a predetermined time and, after this predetermined time, checks again whether the system load of the fuel cell control system 100 is stable. If the system load of the fuel cell control system 100 is already stable, the processor 122 performs the electrochemical analysis described above.
[0031] Please refer to Figure 2 again. After the processor 122 has completed determining the moisture content of the fuel cell 110, it transmits the analysis result ANA to the control device 130. The control device 130 is connected to the fuel cell 110 and the electrochemical detector 120 and is used to adjust the fuel state of the fuel cell 110 by transmitting an adjustment command AD to the fuel cell 110 when the moisture content of the fuel cell 110 is in a dry or flooded state.
[0032] Specifically, when the moisture content of the fuel cell 110 is dry, the control device 130 is used to perform at least one of the following operations: improving the hydrogen gas supply state of the fuel cell 110 (by instructing the hydrogen adjustment subsystem 114), improving the air supply state of the fuel cell 110 (by instructing the hydrogen adjustment subsystem 113), and lowering the temperature state of the fuel cell 110 (by instructing the temperature control subsystem 112). In some embodiments, the operations to improve the air supply state of the fuel cell 110 and lower the temperature state of the fuel cell 110 have a higher priority than the operation to improve the hydrogen gas supply state of the fuel cell 110, thereby saving on adjustment costs.
[0033] On the other hand, if the water content of the fuel cell 110 is in a flooding state, the control device 130 is used to perform at least one of the following operations: reducing the hydrogen gas supply state of the fuel cell 110 (by instructing the hydrogen adjustment subsystem 114); reducing the air supply state of the fuel cell 110 (by instructing the hydrogen adjustment subsystem 113); and improving the temperature state of the fuel cell 110 (by instructing the temperature control subsystem 112). In some embodiments, the operations of reducing the air supply state of the fuel cell 110 and improving the temperature state of the fuel cell 110 have a higher priority than the operation of reducing the hydrogen gas supply state of the fuel cell 110, thereby saving the cost of adjustment.
[0034] After the fuel state of the fuel cell 110 is adjusted by the control device 130, the electrochemical detection device 120 again checks the battery voltage V of the fuel cell 110. FC and battery current I FC The above adjustment method is repeated until the moisture content of the fuel cell 110 is restored to a normal state. With the above control method, the fuel cell control system 100 of this disclosure can achieve the "closed-loop" characteristics of the system.
[0035] The power converter 140 is connected to the fuel cell 110 and the system load 150, and is used to determine the load conditions of the fuel cell 110 and apply these load conditions to the system load 150. When the water content of the fuel cell 110 has recovered to a normal state, the power converter 140 determines the battery voltage V at that time. FC and battery current I FC It is used to generate a corresponding output power supply based on the battery voltage V generated by the fuel cell 110. In some embodiments, the battery voltage V generated by the fuel cell 110 is used to generate the corresponding output power supply. FC and battery current I FC This relates to the current load conditions.
[0036] In some embodiments, the power converter 140 may be implemented by a DC-DC converter, a DC-AC converter, other devices having a conversion function, or any combination of the above.
[0037] In some embodiments, the electrochemical detector 120 and the power converter 140 are installed on different boards within the fuel cell control system 100, respectively, and are connected to each other via a specific transmission method (e.g., a universal asynchronous receiver / transmitter (UART)) to transmit signals to each other. In some embodiments not shown, the electrochemical detector 120 and the power converter 140 are integrated into a single electronic device, and the electrochemical detector 120 may be installed at the front end of this electronic device.
[0038] Figure 6A is a flow chart of a fuel cell control method 600 according to some embodiments of this disclosure. The fuel cell control method 600 is applicable to a fuel cell control system (for example, the fuel cell control system in Figure 2). In some embodiments, the fuel cell control method 600 includes steps S610, S620, S630, S640, S650, S660, S670, S680, and S690.
[0039] In step S610, the load conditions of the fuel cell (e.g., fuel cell 110) are determined by a power converter (e.g., power converter 140). Next, step S620 is executed.
[0040] In step S620, the fuel cell generates the battery voltage and battery current based on the load conditions and the fuel state of the fuel cell. Next, step S630 is performed.
[0041] In step S630, the battery voltage and battery current generated by the fuel cell are detected by a sensor device (for example, sensor device 121). Next, step S640 is performed.
[0042] In step S640, the processor (for example, processor 122) determines whether the system load of the fuel cell control system is already stable. If the system load of the fuel cell control system is not yet stable, step S650 is executed; if the system load of the fuel cell control system is already stable, step S660 is executed.
[0043] In step S650, the processor waits for a predetermined time, and after the waiting period is complete, it executes step S640 again to reconfirm whether the system load of the fuel cell control system has already stabilized.
[0044] In step S660, the processor determines that the system load of the fuel cell control system is already stable, and therefore performs an electrochemical analysis based on the battery voltage and battery current to determine the water content of the fuel cell. Next, step S670 is executed.
[0045] In step S670, the processor determines whether the water content of the fuel cell is in a normal state. If the water content is in a normal state, step S680 is executed. If the water content is not in a normal state (i.e., it is in a dry or flooded state), step S690 is executed.
[0046] In step S680, a power converter generates an output power supply based on the battery voltage and battery current.
[0047] In step S690, the fuel state of the fuel cell is adjusted by a control device (for example, control device 130), and after the adjustment is complete, step S660 is executed again to determine the water content of the fuel cell after the adjustment.
[0048] As mentioned above, if the fuel cell is in a dry or flooded state, the control circuit adjusts the fuel state of the fuel cell in different ways. Therefore, in some embodiments, step S690 includes more steps. See Figure 6B, which is a flow chart of step S690 of a fuel cell control method 600 according to some embodiments of the present disclosure. In some embodiments, step S690 includes steps S690A, S690D, and S690F.
[0049] Step S690A follows step S670. In step S690A, the processor determines whether the fuel cell is in a dry state or a flooded state. If the fuel cell is in a dry state, step S690D is executed; if the fuel cell is in a flooded state, step S690F is executed.
[0050] For a detailed flow of process S690D, please refer to Figure 6C. Figure 6C is a flow diagram of process S690D of the fuel cell control method 600 according to some embodiments of the present disclosure. In process S690D, the control device adjusts the fuel state of the fuel cell relative to the dry state, and in some embodiments, process S690D includes processes S690D1 to S690D8.
[0051] In step S690D1, the control device lowers the temperature state of the fuel cell, and then step S690D2 is executed. In step S690D2, it is determined whether or not the dry state has been released. If the dry state has already been released, step S690D3 is executed; if the dry state has not yet been released, step S690D4 is executed.
[0052] In process S690D3, since the dry state has already been released, the control device completes the adjustment of the fuel state of the fuel cell and maintains the fuel cell in its current fuel state (i.e., temperature state, air supply state, hydrogen gas supply state).
[0053] In step S690D4, if the dry state cannot be resolved by adjusting the temperature state, the control device then improves the air supply state to the fuel cell and continues to execute step S690D5. In step S690D5, it is determined whether or not the dry state has been resolved. If the dry state has already been resolved, step S690D3 is executed; if the dry state has not yet been resolved, step S690D6 is executed.
[0054] In step S690D6, if the dry state cannot be resolved by adjusting the air supply state, the control device then improves the hydrogen gas supply state of the fuel cell and continues to execute step S690D7. In step S690D7, it is determined whether or not the dry state has been resolved. If the dry state has already been resolved, step S690D3 is executed; if the dry state has not yet been resolved, step S690D8 is executed.
[0055] In process S690D8, since the dry state cannot be resolved by adjusting the temperature state, air supply state, and hydrogen gas supply state within the current adjustment range, the control device increases the adjustment range and executes process S690D1 again to adjust the fuel state of the fuel cell with the new adjustment range.
[0056] On the other hand, for a detailed flow of process S690F, please refer to Figure 6D. Figure 6D is a flow diagram of process S690F of the fuel cell control method 600 according to some embodiments of the present disclosure. In process S690F, the fuel state of the fuel cell is adjusted by a control device in response to a flooding state, and in some embodiments, process S690F includes processes S690F1 to S690F8.
[0057] Processes S690F1 to S690F8 in Figure 6D are similar to processes S690D1 to S690D8 in Figure 6C. For the sake of brevity, the following paragraphs will focus on the differences between processes S690F1 to S690F8 and processes S690D1 to S690D8, but the similarities will not be repeated here.
[0058] Specifically, processes S690F1 to S690F8 adjust the fuel state of the fuel cell in response to a flooding state, so the adjustment direction of processes S690F1, S690F4, and S690F6 is the opposite of that of processes S690D1, S690D4, and S690D6 (i.e., the temperature state is improved, the air supply state is reduced, and the hydrogen gas supply state is reduced). On the other hand, processes S690F2, S690F5, and S690F7 determine whether or not the flooding state has been resolved.
[0059] Note that the number and order of steps in the flow diagrams of Figures 6C and 6D are illustrative examples only and do not limit the scope of this disclosure; the number and order of other steps are also within the scope of this disclosure. In some embodiments, steps S690D1 and S690D4 are interchangeable, and steps S690F1 and S690F4 are also interchangeable. In some embodiments, additional steps may be included between steps S690D1 and S690D2 (steps S690F1 and S690F2), between steps S690D4 and S690D5 (steps S690F4 and S690F5), and between steps S690D6 and S690D7 (steps S690F6 and S690F7). In these additional steps, the control device adjusts only one of the following each time in steps S690D and S690F: temperature, air supply, or hydrogen gas supply.
[0060] Through the fuel cell control system 100, electrochemical detection device 120, and fuel cell control method 600 of this disclosure, the water content of the fuel cell can be adjusted in real time to improve the output and lifespan of the fuel cell. Furthermore, the fuel cell control system 100 of this disclosure analyzes the water content of the fuel cell using electrochemical analysis, rather than detecting voltage using a voltage detector and inversely estimating the water content, thus further improving the accuracy of the analysis of the water content of the fuel cell.
[0061] The foregoing are merely preferred embodiments of the present disclosure, and various modifications and equivalent changes can be made to the structure of the present disclosure without departing from the scope or spirit of the present disclosure. In short, all modifications and equivalent changes made to the present disclosure within the scope of the following claims are covered by the present disclosure. [Explanation of symbols]
[0062] 100: Fuel cell control system 110: Fuel cell 110_EIS: Electrochemical Impedance Spectrum 110_HFR: High-frequency resistance plot 111: Battery Stack 112: Temperature control subsystem 113: Air conditioning subsystem 114: Hydrogen regulation subsystem 120: Electrochemical detection device 121: Sensor device 122: Processor 130: Control device 140: Power converter 150: System load 600: Fuel cell control method S610, S620, S630, S640: Process S650, S660, S670, S680: Process S690: Process S690A, S690D, S690F: Process S690D1~S690D8: Process S690F1~S690F8: Process AD: Adjustment command ANA:Analysis results I FC :Battery current V FC Battery voltage Z': Actual impedance Imaginary part of Z'': impedance
Claims
1. A fuel cell control system used to connect to a fuel cell and supply power to a load, An electrochemical detection device connected to the fuel cell, A control device connected to the fuel cell and the electrochemical detection device, which adjusts the fuel state of the fuel cell when the water content of the fuel cell is in a dry or flooded state, A power converter that determines the load conditions of the fuel cell and, when the water content of the fuel cell is in a normal state, generates an output power supply based on the battery voltage and battery current, Includes, The electrochemical detection device is A sensor device for detecting the battery current and battery voltage of the fuel cell, A processor connected to the sensor device, which performs electrochemical analysis based on the battery voltage and the battery current, and determines the water content of the fuel cell based on the electrochemical analysis, Includes, The battery voltage and battery current are related to the fuel cell control system in relation to the load conditions.
2. The fuel state of the fuel cell includes the hydrogen gas supply state, the air supply state, and the temperature state. If the water content of the fuel cell is in the dry state, the control device will An operation to improve the hydrogen gas supply state, An operation to improve the air supply condition, An operation to reduce the aforementioned temperature state, It is used to perform at least one of the following, If the water content of the fuel cell is in the flooding state, the control device will An operation to reduce the hydrogen gas supply state, An operation to reduce the aforementioned air supply state, An operation to improve the temperature state, A fuel cell control system according to claim 1, used to perform at least one of the following.
3. The priority order of operations by the control device to improve the air supply state and decrease the temperature state is higher than the priority order of operations to improve the hydrogen gas supply state, and The fuel cell control system according to claim 2, wherein the priority order of operations by the control device to reduce the air supply state and improve the temperature state is higher than the priority order of operations to reduce the hydrogen gas supply state.
4. The processor is used to generate the measured electrochemical impedance spectrum (EIS) of the fuel cell and the ideal electrochemical impedance spectrum corresponding to the normal state using the electrochemical analysis. The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are, A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is larger than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is greater than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a divergent curve, If at least one of the following is satisfied, the moisture-containing state is the dry state, and The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are, A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is smaller than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is smaller than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a convergence curve, The fuel cell control system according to claim 1, wherein the water content state is in the flooding state if at least one of the following conditions is met.
5. The processor generates a measured high-frequency resistance (HFR) plot of the fuel cell and an ideal high-frequency resistance plot corresponding to the normal state using the electrochemical analysis. Under the same time conditions, if the resistance value in the measured high-frequency resistance plot is greater than the resistance value in the ideal high-frequency resistance plot, then the moisture content is in the dry state. The fuel cell control system according to claim 1, wherein, under the same time conditions, if the resistance value in the measured high-frequency resistance plot is smaller than the resistance value in the ideal high-frequency resistance plot, the water content state is in the flooding state.
6. The fuel cell control system according to claim 1, wherein the processor of the electrochemical detection device further determines whether the system load of the fuel cell control system is stable, and performs the electrochemical analysis after the system load has stabilized.
7. The sensor device detects the battery current and battery voltage of the fuel cell at each inspection cycle, or The fuel cell control system according to any one of claims 1 to 6, wherein the sensor device detects the battery current and battery voltage of the fuel cell when it receives an adjustment command.
8. A fuel cell control method applied to a fuel cell control system, A process of determining the fuel cell load conditions using a power converter, A step of generating a battery voltage and a battery current based on the load conditions and the fuel state of the fuel cell using the fuel cell, A step of detecting the battery voltage and the battery current using a sensor device, A process of determining the water content of the fuel cell by performing electrochemical analysis based on the battery voltage and battery current using a processor, A step of adjusting the fuel state of the fuel cell by a control device when the water content state of the fuel cell is in a dry state or a flooded state, When the water content of the fuel cell is in a normal state, the power converter generates an output power supply based on the battery voltage and the battery current. A fuel cell control method including the following.
9. The fuel state of the fuel cell includes the hydrogen gas supply state, the air supply state, and the temperature state. If the water content of the fuel cell is in the dry state, the step of adjusting the fuel state of the fuel cell with the control device is: A step of improving the hydrogen gas supply state using the control device, A step of improving the air supply state using the control device, A step of lowering the temperature state using the control device, It includes at least one of the following, If the water content state of the fuel cell is in the flooding state, the step of adjusting the fuel state of the fuel cell by the control device is: A step of reducing the hydrogen gas supply state using the control device, A step of reducing the air supply state using the control device, A step of improving the temperature state using the control device, A fuel cell control method according to claim 8, comprising at least one of the above.
10. The priority of the step of improving the air supply state by the control device and the step of lowering the temperature state by the control device is higher than the priority of the step of improving the hydrogen gas supply state by the control device, The fuel cell control method according to claim 9, wherein the priority of the step of reducing the air supply state by the control device and the step of improving the temperature state by the control device is higher than the priority of the step of reducing the hydrogen gas supply state by the control device.
11. The step of determining the water content of the fuel cell by performing the electrochemical analysis based on the battery voltage and battery current using the processor is as follows: The process involves the processor generating a measured electrochemical impedance spectrum (EIS) of the fuel cell and an ideal electrochemical impedance spectrum corresponding to the normal state based on the battery voltage and the battery current. The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is larger than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is greater than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a divergent curve, If at least one of the following conditions is met, the processor determines that the moisture content is in the dry state, The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is smaller than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is smaller than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a convergence curve, If at least one of the following conditions is met, the processor determines that the water content state is in the flooding state, A fuel cell control method according to claim 8, including the following:
12. The step of determining the water content of the fuel cell by performing the electrochemical analysis based on the battery voltage and battery current using the processor is as follows: The process involves the processor generating a measured high-frequency resistance (HFR) plot of the fuel cell based on the battery voltage and the battery current, and an ideal high-frequency resistance plot corresponding to the normal state. If, under the same time conditions, the resistance value in the measured high-frequency resistance plot is greater than the resistance value in the ideal high-frequency resistance plot, the processor determines that the moisture content is in the dry state. If, under the same time conditions, the resistance value in the measured high-frequency resistance plot is smaller than the resistance value in the ideal high-frequency resistance plot, the processor determines that the water content state is the flooding state. A fuel cell control method according to claim 8, including the following:
13. The step of performing the electrochemical analysis based on the battery voltage and battery current using the processor is: The process of determining whether the system load of the fuel cell control system is stable using the processor, If the processor determines that the system load is not yet stable, it will wait for a predetermined time. The process of performing the electrochemical analysis when the processor determines that the system load has already stabilized, A fuel cell control method according to any one of claims 8 to 12, further comprising:
14. The fuel cell control method according to any one of claims 8 to 12, wherein the step of detecting the battery voltage and the battery current by the sensor device is performed at each inspection cycle or when the sensor device receives an adjustment command.
15. An electrochemical detection device connected to a fuel cell, A sensor device used to detect the battery current and battery voltage generated by the fuel cell based on the fuel state, A processor connected to the sensor device, which performs electrochemical analysis based on the battery voltage and battery current, and determines whether the water content of the fuel cell is in a normal state, a dry state, or a flooded state based on the electrochemical analysis, An electrochemical detection device that includes [a specific component].
16. The fuel state of the fuel cell includes the hydrogen gas supply state, the air supply state, and the temperature state. When the water content of the fuel cell is in the dry state, the processor: An operation to instruct the control device to improve the hydrogen gas supply state, An operation to instruct the control device to improve the air supply state, An operation to instruct the control device to lower the temperature state, It is used to perform at least one of the following, If the water content of the fuel cell is in the flooding state, the processor will An operation to instruct the control device to reduce the hydrogen gas supply state, An operation to instruct the control device to reduce the air supply state, An operation to instruct the control device to improve the temperature state, An electrochemical detection apparatus according to claim 15, used to perform at least one of the following.
17. The priority of the operation instructing the control device to improve the air supply state and lower the temperature state is higher than the priority of the operation instructing the control device to improve the hydrogen gas supply state, The electrochemical detection apparatus according to claim 16, wherein the priority of the operation instructing the control device to reduce the air supply state and improve the temperature state is higher than the priority of the operation instructing the control device to reduce the hydrogen gas supply state.
18. The processor is used to generate the measured electrochemical impedance spectrum (EIS) of the fuel cell and the ideal electrochemical impedance spectrum corresponding to the normal state using the electrochemical analysis. The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is larger than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is greater than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a divergent curve, If at least one of the following is satisfied, the processor determines that the moisture-containing state is in the dry state, and, The ideal electrochemical impedance spectrum and the measured electrochemical impedance spectrum are A situation in which the area enclosed by the figure of the measured electrochemical impedance spectrum is smaller than the area enclosed by the figure of the ideal electrochemical impedance spectrum, The situation in which the geometric peak value of the measured electrochemical impedance spectrum is smaller than the geometric peak value of the ideal electrochemical impedance spectrum, The situation in which the measured electrochemical impedance spectrum is a convergence curve, The electrochemical detection device according to claim 15, which determines that the water content state is in the flooding state if at least one of the following conditions is met.
19. The processor generates a measured high-frequency resistance (HFR) plot of the fuel cell and an ideal high-frequency resistance plot corresponding to the normal state using the electrochemical analysis. If, under the same time conditions, the resistance value in the measured high-frequency resistance plot is greater than the resistance value in the ideal high-frequency resistance plot, the processor determines that the moisture content is in the dry state, and The electrochemical detection apparatus according to any one of claims 15 to 18, wherein, under the same time conditions, if the resistance value in the measured high-frequency resistance plot is smaller than the resistance value in the ideal high-frequency resistance plot, the processor determines that the water content state is the flooding state.
20. The electrochemical detection apparatus according to any one of claims 15 to 18, further comprising the processor determining whether the system load of the fuel cell control system in which the fuel cell is provided is stable, and performing the electrochemical analysis after the system load has stabilized.