Fuel cell water balance control method, device and fuel cell system

Abstract

The present application provides a fuel cell water balance control method, device and fuel cell system, wherein the method includes: obtaining the actual operating power of the fuel cell in the fuel cell system when it is running; determining the environmental state of the fuel cell environment based on the actual operating power; in response to the environmental state of the fuel cell environment being an abnormal state, regulating the target physical quantity corresponding to the target subsystem to achieve water balance in the fuel cell environment. Thus, only by monitoring the actual operating power of the fuel cell, the environmental state of the fuel cell environment can be quickly and automatically determined, and a quick response can be made, thereby improving the closed-loop control accuracy and response speed of the water and heat management of the fuel cell system.

Description

Technical Field

[0001] The present application relates to the technical field of fuel cell power systems, and in particular to a fuel cell water balance control method, device and fuel cell system. Background Art

[0002] Generally, the fuel cell power system controls the hydrogen supply subsystem, air subsystem, and cooling subsystem through the electronic control subsystem to pass air and hydrogen into the fuel cell membrane electrode according to the specified process requirements for electrochemical reaction, so as to convert it into direct current and output it through the bipolar plate. Among them, the key factor affecting the life of the fuel cell membrane electrode is the comprehensive water management strategy of the stack. During the operation of the stack (also known as the battery stack), if the stack is dry or flooded for a long time, the output performance of the fuel cell will decrease and the durability will be greatly reduced. Therefore, it is necessary to effectively monitor and close the loop control of the water balance of the fuel cell during actual operation. Summary of the invention

[0003] The present application provides a fuel cell water balance control method, device and fuel cell system to at least solve one of the technical problems in the related art to a certain extent. The technical solution of the present application is as follows:

[0004] According to one aspect of the present application, a fuel cell water balance control method is provided, comprising:

[0005] Obtaining the actual operating power of the fuel cell system when the fuel cell is running;

[0006] Based on the actual operating power, determining an environmental state of an environment in which the fuel cell is located;

[0007] In response to the environmental state of the environment in which the fuel cell is located being in an abnormal state, a target physical quantity corresponding to a target subsystem is regulated so that the environment in which the fuel cell is located reaches a water balance.

[0008] According to another aspect of the present application, a fuel cell water balance control device is provided, the device comprising:

[0009] A first acquisition module is used to acquire the actual operating power of the fuel cell when it is running;

[0010] A first determination module, configured to determine an environmental state of an environment in which the fuel cell is located based on the actual operating power;

[0011] The control module is used to control the target physical quantity corresponding to the target subsystem in response to the environmental state of the environment where the fuel cell is located being an abnormal state, so that the environment where the fuel cell is located reaches a water balance.

[0012] According to another aspect of the present application, a fuel cell system is provided, the system comprising a fuel cell, a fuel cell water balance control device, an AC impedance fixed frequency monitoring module and a target subsystem, wherein:

[0013] The fuel cell water balance control device is used to implement the fuel cell water balance control method proposed in the above aspect of the present application;

[0014] The target subsystem includes at least one of a hydrogen subsystem, an air subsystem, and a cooling subsystem.

[0015] According to another aspect of the present application, a non-transitory computer-readable storage medium of computer instructions is provided, wherein the computer instructions are used to enable the computer to execute the fuel cell water balance control method proposed in the above aspect of the present application.

[0016] According to another aspect of the present application, a computer program product is provided, including a computer program, which, when executed by a processor, implements the fuel cell water balance control method proposed in the above aspect of the present application.

[0017] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0018] The actual operating power of the fuel cell in the fuel cell system is obtained; based on the actual operating power, the environmental state of the fuel cell environment is determined; in response to the environmental state of the fuel cell environment being abnormal, the target physical quantity corresponding to the target subsystem is adjusted to achieve water balance in the fuel cell environment. Therefore, only the actual operating power of the fuel cell needs to be monitored to quickly and automatically determine the environmental state of the fuel cell environment, and a quick response can be made, thereby improving the closed-loop control accuracy and response speed of the water and heat management of the fuel cell system.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 A flow chart of a fuel cell water balance control method provided in Example 1 of the present application;

[0022] Figure 2 A flow chart of a fuel cell water balance control method provided in Example 2 of the present application;

[0023] Figure 3A schematic diagram of the structure of a fuel cell water balance control device provided in one embodiment of the present application;

[0024] Figure 4 This is a schematic diagram of the structure of the fuel cell system provided in this application. DETAILED DESCRIPTION

[0025] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0026] At present, there are two general solutions for water management in hydrogen fuel cell systems in related technologies:

[0027] One method is to build a fuel cell model based on operating data to simulate and calculate the internal humidity of the stack. However, in actual applications, due to large deviations in consistency and differences in environmental conditions, the actual fitting effect of this method is poor and cannot effectively reflect the actual humidity state of the fuel cell stack.

[0028] Another solution is to determine the water content of the battery stack based on the AC impedance spectrum test. This method can effectively characterize the water content inside the battery stack. However, since the AC impedance spectrum test requires a sweep frequency test within 0-2kHz and a fitting calculation of the ohmic impedance for characterization, the actual test time is relatively long. The application-end current and environmental changes will affect the test results, and the response speed is insufficient.

[0029] The related technology cannot effectively monitor the real-time water balance status in the fuel cell stack. Therefore, there is a lack of an effective and fast fuel cell water balance monitoring and control solution.

[0030] In view of the above problems, the present application proposes a fuel cell water balance control method, device and fuel cell system.

[0031] The following describes a fuel cell water balance control method, device and fuel cell system according to embodiments of the present application with reference to the accompanying drawings.

[0032] Figure 1 This is a flow chart of the fuel cell water balance control method provided in Example 1 of the present application.

[0033] The embodiment of the present application takes the fuel cell water balance control method as an example in which it is configured in a fuel cell water balance control device. The fuel cell water balance control device can be applied to any electronic device so that the electronic device can perform the fuel cell water balance control function.

[0034] Among them, the electronic device can be any device with computing capabilities, such as a personal computer, a mobile terminal, a server, etc. The mobile terminal can be, for example, a mobile phone, a tablet computer, a personal digital assistant, a wearable device, and other hardware devices with various operating systems, touch screens and / or display screens.

[0035] like Figure 1 As shown, the fuel cell water balance control method may include the following steps:

[0036] Step 101 : obtaining the actual operating power of a fuel cell in a fuel cell system when the fuel cell is in operation.

[0037] Optionally, the fuel cell system includes, for example, a fuel cell (or a fuel cell stack), a hydrogen subsystem, an air subsystem, a cooling subsystem, etc., which is not limited in the present application.

[0038] It is understandable that the actual output power (referred to as actual operating power in this application) of the fuel cell in the fuel cell system can be monitored, and the actual output power of the fuel cell in the fuel cell system when it is operating can be obtained.

[0039] Step 102: determining the environmental state of the environment in which the fuel cell is located based on the actual operating power.

[0040] The environmental state may be, for example, a relatively dry state (also called a dry state), a relatively wet state (also called a flooded state), and a normal state.

[0041] As an example, experimental tests can be conducted in advance to monitor the actual operating power of the fuel cell under different ambient humidity. Secondly, a correspondence between the ambient humidity and the actual operating power can be established and stored. Thus, when the actual operating power is determined, the above relationship can be queried to determine the ambient humidity corresponding to the actual operating power. Finally, based on the ambient humidity, the environmental state of the environment in which the fuel cell is located under the ambient humidity is determined.

[0042] Step 103 , in response to the environmental state of the fuel cell environment being an abnormal state, regulating the target physical quantity corresponding to the target subsystem so that the fuel cell environment reaches a water balance.

[0043] The abnormal state may include a relatively dry state and a relatively wet state.

[0044] As a possible implementation manner, the target subsystem may include at least one of a hydrogen subsystem, an air subsystem, and a cooling subsystem; and when the target subsystem is a hydrogen subsystem, the target physical quantity corresponding to the hydrogen subsystem includes air supply humidity and / or gas pressure; when the target subsystem is an air subsystem, the target physical quantity corresponding to the air subsystem includes air supply humidity and / or gas flow; when the target subsystem is a cooling subsystem, the target physical quantity corresponding to the cooling subsystem includes cooling temperature.

[0045] In the embodiment of the present application, when the environmental state of the environment in which the fuel cell is located is abnormal, the target physical quantity corresponding to the target subsystem can be adjusted so that the environment in which the fuel cell is located reaches a water balance.

[0046] As an example, when the environmental state of the fuel cell environment is relatively dry, the air supply humidity and gas pressure of the hydrogen subsystem can be regulated, for example, by increasing the air supply humidity and increasing the gas pressure; when the environmental state of the fuel cell environment is relatively humid, the air supply humidity and gas pressure of the hydrogen subsystem can be regulated, for example, by reducing the air supply humidity and reducing the gas pressure.

[0047] It should be noted that the above examples of regulating the hydrogen subsystem are merely illustrative, and in practical applications, there may be other examples, which are not limited in this application.

[0048] It should be noted that when regulating the target physical quantity corresponding to the target subsystem, it is necessary to execute within the adjustable range to avoid exceeding the reasonable range of the target physical quantity or exceeding the response capability of each component of the fuel cell system.

[0049] The fuel cell water balance control method of the embodiment of the present application obtains the actual operating power of the fuel cell in the fuel cell system; determines the environmental state of the fuel cell environment based on the actual operating power; and in response to the environmental state of the fuel cell environment being an abnormal state, adjusts the target physical quantity corresponding to the target subsystem to achieve water balance in the fuel cell environment. Therefore, only the actual operating power of the fuel cell needs to be monitored to quickly and automatically determine the environmental state of the fuel cell environment, and quickly respond, thereby improving the closed-loop control accuracy and response speed of the water and heat management of the fuel cell system.

[0050] In order to clearly explain how the environmental state of the fuel cell environment is determined based on the actual operating power in the above embodiments of the present application, the present application also proposes a fuel cell water balance control method.

[0051] Figure 2 This is a flow chart of the fuel cell water balance control method provided in Example 2 of the present application.

[0052] like Figure 2As shown, the fuel cell water balance control method may include the following steps:

[0053] Step 201 : obtaining the actual operating power of a fuel cell in a fuel cell system when the fuel cell is in operation.

[0054] The execution process of step 201 can refer to the execution process of any embodiment of the present application, and will not be repeated here.

[0055] Step 202, obtain the dry-sensitive frequency and the wet-sensitive frequency corresponding to the real-time operating power, as well as the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency.

[0056] The first characteristic parameter may be, but is not limited to, impedance, phase, etc.

[0057] The second characteristic parameter may be, but is not limited to, impedance, phase, etc.

[0058] It should be noted that the first characteristic parameter and the second characteristic parameter may be the same or different, and this application does not impose any limitation on this.

[0059] Optionally, before obtaining the dry-sensitive frequency and the wet-sensitive frequency corresponding to the real-time operating power, and the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency, and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency, the following steps may be performed:

[0060] 1. Obtain multiple possible operating powers when the fuel cell is running.

[0061] It should be noted that the possible operating power must be within the power range required for the operation of the fuel cell system.

[0062] 2. For any possible operating power, perform AC impedance sweep measurement on the fuel cell at multiple ambient humidity and target sweep frequency range under the possible operating power to obtain an AC impedance spectrum at the corresponding ambient humidity and reference frequency.

[0063] The frequency sweep value range includes multiple reference frequencies, and the frequency sweep value range may include but is not limited to 2-1000 Hz.

[0064] 3. Based on each AC impedance spectrum, a correlation analysis is performed on the water content corresponding to each ambient humidity and each reference frequency to determine the dry-sensitive frequency and wet-sensitive frequency corresponding to the possible operating power.

[0065] As an example, statistical methods (such as Pearson correlation coefficient, Spearman rank correlation coefficient, etc.) can be used to perform correlation analysis on the water content corresponding to each ambient humidity and each reference frequency based on each AC impedance spectrum to determine the dry-sensitive frequency and wet-sensitive frequency corresponding to the possible operating power of the fuel cell.

[0066] 4. Determine a first reference value range of the first characteristic parameter under possible operating power and dry-sensitive frequency, and determine a second reference value range of the second characteristic parameter under possible operating power and wet-sensitive frequency.

[0067] Among them, the first reference value range of the first characteristic parameter at the possible operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter at the possible operating power and the wet-sensitive frequency can be determined according to the process design of the fuel cell system. Under different process designs, the first reference value range of the first characteristic parameter at the possible operating power and the dry-sensitive frequency can be different, and the second reference value range of the second characteristic parameter at the possible operating power and the wet-sensitive frequency can also be different. Therefore, this application does not limit the setting of the first reference value range and the second reference value range.

[0068] In this way, the correspondence between the possible operating power and the dry-sensitive frequency and the wet-sensitive frequency can be effectively obtained, and the first reference value range of the first characteristic parameter under the possible operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter under the possible operating power and the wet-sensitive frequency can be obtained.

[0069] In a possible implementation of the present application, the correspondence between possible operating power and dry-sensitive frequency and wet-sensitive frequency can be stored, and a first reference value range of the first characteristic parameter under the possible operating power and dry-sensitive frequency and a second reference value range of the second characteristic parameter under the possible operating power and wet-sensitive frequency can be stored.

[0070] Therefore, in the present application, the above-mentioned corresponding relationship can be queried and stored according to the actual operating power, and the dry-sensitive frequency and the wet-sensitive frequency corresponding to the actual operating power can be obtained, and the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency can be determined.

[0071] Step 203, alternately injecting the first AC signal and the second AC signal into the AC impedance constant frequency monitoring module in the fuel cell system; wherein the frequency of the first AC signal is a dry-sensitive frequency, the frequency of the second AC signal is a wet-sensitive frequency, and the first AC signal and the second AC signal are switched at a corresponding periodic fixed frequency.

[0072] The AC impedance constant frequency monitoring module may be integrated into a DCDC converter (DC-to-DC converter).

[0073] It should be noted that, in the present application, the duration of the cycle corresponding to the first alternating current signal and the duration of the cycle corresponding to the second alternating current signal may be the same or different, and the present application does not impose any limitation on this.

[0074] It should be pointed out that when the first AC signal and the second AC signal are switched at a corresponding fixed frequency cycle, only one frequency AC signal can be injected into the AC impedance fixed frequency monitoring module at any time, and overlapping injection of dual-frequency and multi-frequency signals is not supported.

[0075] Step 204 , based on the actual value of the characteristic parameter under the AC signal injected into the AC impedance constant frequency monitoring module, and the first reference value range or the second reference value range, determine the environmental state of the environment in which the fuel cell is located.

[0076] The characteristic parameters include a first characteristic parameter and a second characteristic parameter, and the alternating current signal includes a first alternating current signal and a second alternating current signal.

[0077] In the embodiment of the present application, the actual value of the characteristic parameter under the AC signal injected into the AC impedance constant frequency monitoring module is used to characterize the value of the characteristic parameter under the AC signal of the actual operating power and corresponding frequency in the fuel cell system.

[0078] Therefore, in the present application, the environmental state of the fuel cell environment can be determined based on the actual value of the characteristic parameter under the AC signal injected into the AC impedance constant frequency monitoring module, and the first reference value range or the second reference value range.

[0079] As a possible implementation method, when a first AC signal is injected into the AC impedance constant frequency monitoring module, the environmental state of the fuel cell environment can be determined based on the first actual value of the first characteristic parameter under the first AC signal injected into the AC impedance constant frequency monitoring module and the first reference value range.

[0080] Optionally, when the first actual value does not belong to the first reference value range, the environmental state of the fuel cell environment is determined to be a dry state; when the first actual value belongs to the first reference value range, the environmental state of the fuel cell environment is determined to be a normal state.

[0081] As another possible implementation method, when a second AC signal is injected into the AC impedance constant frequency monitoring module, the environmental state of the fuel cell environment can be determined based on a second actual value of the second characteristic parameter under the second AC signal injected into the AC impedance constant frequency monitoring module and a second reference value range.

[0082] Optionally, when the second actual value does not belong to the second reference value range, the environmental state of the fuel cell environment is determined to be a humid state; when the second actual value belongs to the second reference value range, the environmental state of the fuel cell environment is determined to be a normal state.

[0083] Step 205 , in response to the environmental state of the fuel cell environment being an abnormal state, regulating the target physical quantity corresponding to the target subsystem so that the fuel cell environment reaches a water balance.

[0084] The execution process of step 205 can refer to the execution process of any embodiment of the present application, and will not be repeated here.

[0085] In order to prevent over-control, as a possible implementation method, when the environmental state of the fuel cell environment is determined to be a dry state based on the first actual value of the first AC signal injected into the AC impedance constant frequency monitoring module and the first reference value range of the first characteristic parameter, the AC signal injected into the AC impedance constant frequency monitoring module is switched to a second AC signal with a frequency that is a wet sensitive frequency, and subsequently based on the third actual value and the second reference value range of the second AC signal injected into the AC impedance constant frequency monitoring module based on the second characteristic parameter, the environmental state of the fuel cell environment is continuously monitored.

[0086] Similarly, when the environmental state of the fuel cell environment is determined to be a relatively humid state based on the second actual value of the second AC signal injected into the AC impedance constant frequency monitoring module and the second reference value range of the second characteristic parameter, the AC signal injected into the AC impedance constant frequency monitoring module is switched to the first AC signal with a relatively dry sensitive frequency, and subsequently based on the fourth actual value of the first AC signal injected into the AC impedance constant frequency monitoring module based on the first characteristic parameter and the second reference value range of the first AC signal, the environmental state of the fuel cell environment is continuously monitored.

[0087] The fuel cell water balance control method of the embodiment of the present application, by obtaining the dry-sensitive frequency and wet-sensitive frequency corresponding to the real-time operating power, as well as the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency; alternately injecting the first AC signal and the second AC signal into the AC impedance constant frequency monitoring module in the fuel cell system; wherein the frequency of the first AC signal is the dry-sensitive frequency, the frequency of the second AC signal is the wet-sensitive frequency, and the first AC signal and the second AC signal are switched at a corresponding periodic fixed frequency; based on the actual value of the characteristic parameter under the AC signal injected into the AC impedance constant frequency monitoring module, and the first reference value range or the second reference value range, the environmental state of the environment in which the fuel cell is located is determined. Therefore, it is only necessary to combine the actual value of the characteristic parameter in the AC impedance constant frequency monitoring module and the reference value range of the characteristic parameter to quickly and intelligently determine the environmental humidity of the environment in which the fuel cell is located, which can effectively improve the feedback rate of the change of the humidity in the environment in which the fuel cell is located, and has real-time performance.

[0088] In order to clearly illustrate the fuel cell water balance control method of the present application, a detailed description is given below with reference to examples.

[0089] As an example, the following steps may be used to implement the fuel cell water balance control method of the present application:

[0090] 1. Preprocessing

[0091] 1. According to the required power range of the fuel cell operation in the fuel cell system, and the reasonable operating parameter range of humidity and / or humidity, full-frequency AC impedance sweep measurement is performed at each power point among multiple possible operating power points to obtain an AC impedance spectrum, wherein the target sweep frequency range includes but is not limited to 2-1000Hz;

[0092] 2. For any possible operating power, based on each AC impedance spectrum, the correlation between the stack and the water content at each frequency point is statistically analyzed to determine the dry-sensitive frequency f1 and wet-sensitive frequency f2 of the fuel cell corresponding to the possible operating power; wherein the characteristic parameter of the dry-sensitive frequency f1 is M1, and the characteristic parameter of the wet-sensitive frequency f2 is M2, and M1 and M2 may be, but are not limited to, typical characteristic parameters such as impedance and phase at the corresponding frequency;

[0093] 3. Determine the reasonable range M1 of the characteristic parameter M1 (referred to as the first characteristic parameter in this application) at each power point under the partial-dry sensitive frequency f1 a -M1 b(recorded as the first reference value range in this application), and determine the reasonable range M2 of the characteristic parameter M2 (recorded as the second characteristic parameter in this application) at each power point of the humidity sensitive frequency f1 a -M2 b (Recorded as the second reference value range in this application).

[0094] 4. Store the corresponding relationship between each power point and the dry sensitive frequency and the wet sensitive frequency, and store the reasonable range of the characteristic parameter M1 at each power point under the dry sensitive frequency and the reasonable range of the characteristic parameter M2 at each power point under the wet sensitive frequency.

[0095] 2. Actual operation

[0096] 1. Monitor the actual operating power of the fuel cell in the fuel cell system when the fuel cell is running;

[0097] 2. According to the actual operating power, query the stored corresponding relationship and obtain the dry sensitive frequency f1 and the wet sensitive frequency f2 corresponding to the actual operating power;

[0098] 3. Alternately injecting a first alternating current signal corresponding to the dry sensitive frequency f1 and a second alternating current signal corresponding to the wet sensitive frequency f2 into the AC impedance constant frequency monitoring module; wherein the first alternating current signal and the second alternating current signal are switched at a corresponding fixed frequency cycle;

[0099] 4. When the AC signal injected into the AC impedance fixed-frequency monitoring module is the first AC signal, the first actual value and reasonable range M1 of the first AC signal injected into the AC impedance fixed-frequency monitoring module based on the characteristic parameter M1 a -M1 b , determine whether the environmental state of the fuel cell environment is dry or normal;

[0100] When the AC signal injected by the AC impedance fixed-frequency monitoring module is the second AC signal, the second actual value and reasonable range M2 of the second AC signal injected into the AC impedance fixed-frequency monitoring module based on the characteristic parameter M2 a -M2 b , determine whether the environmental state of the fuel cell environment is a humid state or a normal state.

[0101] 5. When it is determined that the environmental state of the fuel cell environment is abnormal (dry or wet), the target physical quantity corresponding to the target subsystem is regulated to achieve water balance in the fuel cell environment.

[0102] It should be noted that in the process of regulating the target physical quantity corresponding to the target subsystem, it is necessary to control it within the adjustable range of the target physical quantity to avoid overflowing the reasonable range corresponding to the target physical quantity or exceeding the response capacity of the component during the water balance regulation process.

[0103] Moreover, in the case where the AC signal injected into the AC impedance fixed-frequency monitoring module is the first AC signal, when it is determined that the environmental state of the fuel cell environment is in a dry state, the AC signal injected into the AC impedance fixed-frequency monitoring module is switched to a second AC signal with a frequency of the wet sensitive frequency f2, and then based on the characteristic parameter M2, the third actual value and reasonable range M2 of the second AC signal injected into the AC impedance fixed-frequency monitoring module is a -M2 b , continuously monitor the environmental state of the fuel cell environment until the third actual value falls within the reasonable range M2 a -M2 b , at this time, the environmental state of the fuel cell environment is normal;

[0104] Similarly, in the case where the AC signal injected into the AC impedance fixed-frequency monitoring module is the second AC signal, when it is determined that the environmental state of the fuel cell environment is a humid state, the AC signal injected into the AC impedance fixed-frequency monitoring module is switched to the first AC signal with a frequency of the humid sensitive frequency f1, and the fourth actual value and reasonable range M1 of the first AC signal injected into the AC impedance fixed-frequency monitoring module based on the characteristic parameter M1 is subsequently a -M1 b , continuously monitor the environmental state of the fuel cell environment until the fourth actual value falls within the reasonable range M1 a -M1 b At this time, the environmental state of the fuel cell environment is normal.

[0105] The fuel cell water balance control method of the present application has the following advantages:

[0106] 1. Based on the demand for fuel cell (or stack) humidity control, determine the AC constant-frequency impedance monitoring method that characterizes the humidity of the fuel cell (or stack), and carry out humidity closed-loop control based on the reasonable range of the characteristic parameters of the fixed-frequency AC and the adjustable range of system operation to improve the power generation performance of the fuel cell system and extend the life of the fuel cell stack.

[0107] 2. Carry out humidity characterization of fuel cells (or stacks) based on constant-frequency AC impedance technology. Inject AC signals through the internal circuit of the existing DCDC converter of the fuel cell system to eliminate the instruments required for humidity monitoring, reduce the cost of the fuel cell system, and improve system reliability.

[0108] 3. The AC injection circuit is used for humidity characterization. The actual characterization parameter (i.e., characteristic parameter) can be the actual internal impedance component of the fuel cell (or stack). Compared with the humidity meter installed at the entrance and exit of the stack, it can more effectively reflect the humidity conditions inside the stack, and is more sensitive than common humidity meters when the humidity drops rapidly.

[0109] In summary, compared with the inherent AC impedance characterization of the water content of the fuel cell stack and the humidity sensor monitoring method, the fuel cell water balance control method of the present application emphasizes the rapid real-time characterization of the water content of the fuel cell through multiple fixed groups of frequencies, and combines the water management control range (or reasonable parameter range) to effectively improve the water management control response speed.

[0110] With the above Figure 1 to Figure 2 Corresponding to the fuel cell water balance control method provided in the embodiment, the present application also provides a fuel cell water balance control device. Since the fuel cell water balance control device provided in the embodiment of the present application is consistent with the above Figure 1 to Figure 2 The fuel cell water balance control method provided in the embodiment corresponds to the embodiment, so the implementation of the fuel cell water balance control method is also applicable to the fuel cell water balance control device provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0111] Figure 3 This is a schematic diagram of the structure of a fuel cell water balance control device provided in one embodiment of the present application.

[0112] like Figure 3 As shown, the fuel cell water balance control device 300 may include: an acquisition module 301 , a determination module 302 and a regulation module 303 .

[0113] The first acquisition module 301 is used to acquire the actual operating power of the fuel cell in the fuel cell system when the fuel cell is in operation.

[0114] The first determination module 302 is used to determine the environmental state of the environment where the fuel cell is located based on the actual operating power.

[0115] The control module 303 is used to control the target physical quantity corresponding to the target subsystem in response to the environmental state of the fuel cell being in an abnormal state, so that the fuel cell environment reaches a water balance.

[0116] In a possible implementation of an embodiment of the present application, the first determination module 302 is used to: obtain a dry-sensitive frequency and a wet-sensitive frequency corresponding to the real-time operating power, as well as a first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency and a second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency; alternately inject the first AC signal and the second AC signal into the AC impedance constant-frequency monitoring module in the fuel cell system; wherein the frequency of the first AC signal is the dry-sensitive frequency, the frequency of the second AC signal is the wet-sensitive frequency, and the first AC signal and the second AC signal are switched at a corresponding periodic fixed frequency; based on the actual value of the characteristic parameter under the AC signal injected into the AC impedance constant-frequency monitoring module, as well as the first reference value range or the second reference value range, determine the environmental state of the environment in which the fuel cell is located.

[0117] In a possible implementation of an embodiment of the present application, the actual value includes a first actual value and a second actual value; the first determination module 302 is used to: determine the environmental state of the environment in which the fuel cell is located based on the first actual value of the first characteristic parameter under the first alternating current signal injected into the AC impedance constant frequency monitoring module and the first reference value range; or, determine the environmental state of the environment in which the fuel cell is located based on the second actual value of the second characteristic parameter under the second alternating current signal injected into the AC impedance constant frequency monitoring module and the second reference value range.

[0118] In a possible implementation of the embodiment of the present application, the first determination module 302 is used to: in response to the first actual value not belonging to the first reference value range, determine that the environmental state of the environment in which the fuel cell is located is a dry state;

[0119] In response to the first actual value belonging to the first reference value range, it is determined that the environmental state of the environment in which the fuel cell is located is a normal state.

[0120] In a possible implementation of an embodiment of the present application, the first determination module 302 is used to: in response to the second actual value not falling within the second reference value range, determine that the environmental state of the environment in which the fuel cell is located is a humid state; in response to the second actual value falling within the second reference value range, determine that the environmental state of the environment in which the fuel cell is located is a normal state.

[0121] In a possible implementation of the embodiment of the present application, the fuel cell water balance control device 300 may further include:

[0122] The second acquisition module is used to acquire a plurality of possible operating powers when the fuel cell is in operation.

[0123] The measurement module is used to perform AC impedance sweep measurement on the fuel cell at multiple ambient humidity and target sweep frequency range for any possible operating power, so as to obtain the AC impedance spectrum at the corresponding ambient humidity and reference frequency; wherein the sweep frequency value range includes multiple reference frequencies.

[0124] The analysis module is used to perform correlation analysis on the water content corresponding to each ambient humidity and each reference frequency based on each AC impedance spectrum, so as to determine the dry-sensitive frequency and the wet-sensitive frequency corresponding to the possible operating power.

[0125] The second determination module is used to determine a first reference value range of the first characteristic parameter under possible operating power and dry-sensitive frequency, and to determine a second reference value range of the second characteristic parameter under possible operating power and wet-sensitive frequency.

[0126] In a possible implementation of the embodiment of the present application, the fuel cell water balance control device 300 may further include:

[0127] A storage module is used to store the correspondence between possible operating power and dry-sensitive frequency and wet-sensitive frequency, and to store a first reference value range of a first characteristic parameter under possible operating power and dry-sensitive frequency and a second reference value range of a second characteristic parameter under possible operating power and wet-sensitive frequency.

[0128] In a possible implementation of an embodiment of the present application, the target subsystem includes at least one of a hydrogen subsystem, an air subsystem, and a cooling subsystem; wherein the target physical quantity corresponding to the hydrogen subsystem includes air supply humidity and / or gas pressure, the target physical quantity corresponding to the air system includes air supply humidity and / or gas flow, and the target physical quantity corresponding to the cooling subsystem includes cooling temperature.

[0129] The fuel cell water balance control device of the embodiment of the present application obtains the actual operating power of the fuel cell in the fuel cell system; determines the environmental state of the fuel cell environment based on the actual operating power; and in response to the environmental state of the fuel cell environment being an abnormal state, adjusts the target physical quantity corresponding to the target subsystem to achieve water balance in the fuel cell environment. Therefore, only the actual operating power of the fuel cell needs to be monitored to quickly and automatically determine the environmental state of the fuel cell environment, and quickly respond, thereby improving the closed-loop control accuracy and response speed of the water and heat management of the fuel cell system.

[0130] In order to implement the above embodiment, the present application also proposes a fuel cell system, wherein the system includes a fuel cell, a fuel cell water balance control device, an AC impedance constant frequency monitoring module and a target subsystem, wherein:

[0131] A fuel cell water balance control device is used to implement the fuel cell water balance control method proposed in the above aspect of the present application.

[0132] The target subsystem includes at least one of a hydrogen subsystem, an air subsystem, and a cooling subsystem.

[0133] In order to clearly illustrate the fuel cell system of the present application, an example is provided below for explanation.

[0134] Still using the above example to explain, Figure 4 This is a structural schematic diagram of the fuel cell system provided in the present application, wherein the fuel cell system 400 includes a fuel cell (or a stack) 410, a fuel cell water balance control device 420, an AC impedance constant frequency monitoring module 430, a target subsystem 440 and a preprocessing module 450, wherein the fuel cell water balance control device 420 includes a first data acquisition module (referred to as a first acquisition module in the present application) 421, a second data acquisition module (referred to as a first determination module in the present application) 422, and a control operation unit (referred to as a regulation module in the present application) 423, and the target subsystem 440 includes a hydrogen subsystem 441, an air subsystem 442 and a cooling subsystem 443.

[0135] The first data acquisition module 421 is used to monitor the fuel cell 410 in the fuel cell system to obtain the actual operating power of the fuel cell 410 when it is running, and can also obtain the humidity and temperature of the environment where the fuel cell 410 is located.

[0136] The second data acquisition module 422 is connected to the preprocessing module 450 and is used to obtain the dry sensitive frequency and the wet sensitive frequency corresponding to the real-time operating power from the preprocessing module 450, as well as the reasonable range M1 of the characteristic parameter M1 under the actual operating power and the dry sensitive frequency. a -M1 b The reasonable range of characteristic parameter M2 under actual operating power and humidity sensitive frequency M1 a -M1 b ; Alternately inject the first AC signal corresponding to the dry sensitive frequency f1 and the second AC signal corresponding to the wet sensitive frequency f2 into the AC impedance fixed frequency monitoring module 430; wherein the first AC signal and the second AC signal are switched at a fixed frequency according to the corresponding period; when the AC signal injected by the AC impedance fixed frequency monitoring module 430 is the first AC signal, the first actual value and reasonable range M1 of the first AC signal injected into the AC impedance fixed frequency monitoring module 430 based on the characteristic parameter M1 a -M1 b, determine whether the environmental state of the environment in which the fuel cell 410 is located is a dry state or a normal state; when the AC signal injected by the AC impedance fixed frequency monitoring module 430 is a second AC signal, based on the characteristic parameter M2, the second actual value and reasonable range M2 of the second AC signal injected in the AC impedance fixed frequency monitoring module 430 a -M2 b , determine whether the environmental state of the environment in which the fuel cell 410 is located is a humid state or a normal state.

[0137] The control operation unit 423 is connected to the second data acquisition module 422, and is used to adjust the target physical quantity corresponding to the target subsystem 440 when it is determined that the environmental state of the environment in which the fuel cell 410 is located is an abnormal state (a relatively dry state or a relatively wet state), so that the environment in which the fuel cell is located reaches a water balance.

[0138] Among them, the control operation unit 423 is the main control element for realizing the fuel cell AC impedance characterization operation and closed-loop control of the hydrogen / air / cooling subsystem. Combined with the dry and wet states of the actual fuel cell stack characterized in real time, closed-loop regulation is performed by controlling the air supply humidity and gas pressure of the hydrogen subsystem, the air supply humidity and gas flow of the air subsystem, and the temperature of the cooling subsystem.

[0139] When the stack is in a normal state, the hydrogen / air / cooling subsystem is not adjusted and continuously monitored; when the stack is in a dry state, it can be dynamically adjusted by reducing the air flow / increasing the hydrogen pressure / increasing the humidity of the hydrogen and air supply / reducing the cooling temperature, etc., until the measured M1 value is within the reasonable parameter range M1 a -M1 b When the stack is in a wet state, it can be dynamically adjusted by increasing air flow / reducing hydrogen pressure / reducing hydrogen and air humidity / increasing cooling temperature, etc., until the measured M2 value is within the reasonable parameter range M2 a -M2 b .

[0140] The preprocessing module 450 is connected to the first data acquisition module 421, the second data acquisition module 422 and the AC impedance fixed frequency monitoring module 430, and is used to obtain multiple possible operating powers when the fuel cell is running; for any possible operating power, the fuel cell is subjected to AC impedance sweep measurement under multiple ambient humidity and target sweep frequency range under the possible operating power to obtain the AC impedance spectrum under the corresponding ambient humidity and reference frequency; wherein the sweep frequency value range includes multiple reference frequencies; based on each AC impedance spectrum, the water content corresponding to each ambient humidity and each reference frequency are subjected to correlation analysis to determine the dry sensitive frequency f1 and the wet sensitive frequency f2 corresponding to the possible operating power; and the reasonable range M1 of the characteristic parameter M1 under the possible operating power and the dry sensitive frequency f1 is determined.a -M1 b , and determine the reasonable range of characteristic parameter M2 under possible operating power and partial humidity sensitive frequency f2 a -M2 b .

[0141] The preprocessing module 450 can also be used to store the corresponding relationship between the possible operating power and the dry sensitive frequency f1 and the wet sensitive frequency f2, and store the reasonable range M1 of the characteristic parameter M1 under the possible operating power and the dry sensitive frequency f1. a -M1 b The reasonable range of characteristic parameter M2 under possible operating power and humidity sensitive frequency f2 a -M2 b .

[0142] Among them, the main technical points are as follows:

[0143] 1. Based on the dry, wet and normal conditions within the actual operating power range of the stack, the stack AC impedance spectrum is measured using AC impedance sweep frequency;

[0144] 2. Use the correlation analysis method to identify the dry-sensitive frequency and wet-sensitive frequency of the stack, import the corresponding AC signal into the AC impedance fixed frequency module, and configure the single frequency single injection duration and switching cycle;

[0145] 3. Collect the ambient temperature, humidity and stack operating power to determine the reasonable range of characteristic parameters of the stack when it is in water balance at frequencies f1 and f2;

[0146] 4. In response to the characteristic parameters being within a reasonable range, the fuel cell system is not adjusted and continues to monitor;

[0147] 5. In response to characteristic parameters overflowing a reasonable range, water balance closed-loop control is performed by adjusting relevant parameters of the hydrogen / air / cooling subsystem.

[0148] In summary, the fuel cell system of the present application can effectively characterize the water balance state of the fuel cell and improve the robustness of the water balance monitoring of the system under different environments and operating powers; it adopts the "AC impedance dual-frequency monitoring" method to characterize the dry and wet state of the fuel cell stack, effectively improving the feedback sensitivity of humidity changes, and providing an effective basis for fast and accurate closed-loop water management in actual engineering applications.

[0149] In order to implement the above embodiments, the present application also proposes an electronic device, wherein the electronic device can be the server or detection device in the aforementioned embodiments; it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the program, it implements the fuel cell water balance control method proposed in any of the aforementioned embodiments of the present application.

[0150] In order to implement the above embodiments, the present application also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the fuel cell water balance control method proposed in any of the above embodiments of the present application is implemented.

[0151] In order to implement the above embodiments, the present application also proposes a computer program product. When the instructions in the computer program product are executed by a processor, the fuel cell water balance control method proposed in any of the above embodiments of the present application is executed.

[0152] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0153] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0154] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0155] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0156] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0157] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0158] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0159] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A fuel cell water balance control method, characterized in that: The method comprises: Obtaining the actual operating power of the fuel cell system when the fuel cell is running; Obtain the dry-sensitive frequency and the wet-sensitive frequency corresponding to the actual operating power, as well as the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency, alternately inject the first AC signal and the second AC signal into the AC impedance constant-frequency monitoring module in the fuel cell system according to the corresponding period, and determine whether the environmental state of the environment in which the fuel cell is located is normal based on the first actual value of the first characteristic parameter under the first AC signal injected into the AC impedance constant-frequency monitoring module and the first reference value range, or based on the second actual value of the second characteristic parameter under the second AC signal injected into the AC impedance constant-frequency monitoring module and the second reference value range: if the first actual value does not belong to the first reference value range, determine that the environmental state of the environment in which the fuel cell is located is abnormal; if the second actual value does not belong to the second reference value range, determine that the environmental state of the environment in which the fuel cell is located is abnormal; wherein the frequency of the first AC signal is the dry-sensitive frequency, and the frequency of the second AC signal is the wet-sensitive frequency; In response to the environmental state of the environment in which the fuel cell is located being an abnormal state, the target physical quantity corresponding to the target subsystem is regulated to make the environment in which the fuel cell is located reach water balance, wherein the target subsystem includes a hydrogen subsystem, an air subsystem, and / or a cooling subsystem, the target physical quantity corresponding to the hydrogen subsystem includes air supply humidity and gas pressure, the target physical quantity corresponding to the air subsystem includes air supply humidity and gas flow, and the target physical quantity corresponding to the cooling subsystem includes cooling temperature.

2. The method according to claim 1, characterized in that Determining whether the environmental state of the environment in which the fuel cell is located is normal based on a first actual value of the first characteristic parameter under the first alternating current signal injected into the alternating current impedance fixed frequency monitoring module and the first reference value range, or based on a second actual value of the second characteristic parameter under the second alternating current signal injected into the alternating current impedance fixed frequency monitoring module and the second reference value range, further comprising: If the first actual value belongs to the first reference value range, it is determined that the environmental state of the environment in which the fuel cell is located is a normal state.

3. The method according to claim 1, characterized in that Determining whether the environmental state of the environment in which the fuel cell is located is normal based on a first actual value of the first characteristic parameter under the first alternating current signal injected into the alternating current impedance fixed frequency monitoring module and the first reference value range, or based on a second actual value of the second characteristic parameter under the second alternating current signal injected into the alternating current impedance fixed frequency monitoring module and the second reference value range, further comprising: If the second actual value belongs to the second reference value range, it is determined that the environmental state of the environment in which the fuel cell is located is a normal state.

4. The method according to claim 1, characterized in that: Before obtaining the dry-sensitive frequency and the wet-sensitive frequency corresponding to the actual operating power, and the first reference value range of the first characteristic parameter under the actual operating power and the dry-sensitive frequency, and the second reference value range of the second characteristic parameter under the actual operating power and the wet-sensitive frequency, the method further includes: Acquire a plurality of possible operating powers when the fuel cell is in operation, wherein the possible operating powers are within a required operating power range of the fuel cell system; For any of the possible operating powers, performing AC impedance sweep measurement on the fuel cell at multiple ambient humidity and within a target sweep frequency range under the possible operating power to obtain an AC impedance spectrum at the corresponding ambient humidity and reference frequency; wherein the sweep frequency value range includes multiple reference frequencies; Based on each of the AC impedance spectra, correlation analysis is performed on the water content corresponding to each of the ambient humidity and each of the reference frequencies to determine a dry-sensitive frequency and a wet-sensitive frequency corresponding to the possible operating power; A first reference value range of the first characteristic parameter at the possible operating power and the dry-sensitive frequency is determined, and a second reference value range of the second characteristic parameter at the possible operating power and the wet-sensitive frequency is determined.

5. The method according to claim 4, characterized in that The method further comprises: The correspondence between the possible operating power and the dry-sensitive frequency and the wet-sensitive frequency is stored, and a first reference value range of the first characteristic parameter at the possible operating power and the dry-sensitive frequency and a second reference value range of the second characteristic parameter at the possible operating power and the wet-sensitive frequency are stored.

6. A fuel cell water balance control device, characterized in that: The device comprises: A first acquisition module is used to acquire the actual operating power of the fuel cell when it is running; A first determination module is used to obtain a dry-sensitive frequency and a wet-sensitive frequency corresponding to the actual operating power, as well as a first reference value range of a first characteristic parameter under the actual operating power and the dry-sensitive frequency and a second reference value range of a second characteristic parameter under the actual operating power and the wet-sensitive frequency, and alternately inject a first alternating current signal and a second alternating current signal into an alternating current impedance constant frequency monitoring module in a fuel cell system according to corresponding periods, and determine whether the environmental state of the environment in which the fuel cell is located is a normal state based on a first actual value of the first characteristic parameter under the first alternating current signal injected into the alternating current impedance constant frequency monitoring module and the first reference value range, or based on a second actual value of the second characteristic parameter under the second alternating current signal injected into the alternating current impedance constant frequency monitoring module and the second reference value range: if the first actual value does not belong to the first reference value range, it is determined that the environmental state of the environment in which the fuel cell is located is an abnormal state, and if the second actual value does not belong to the second reference value range, it is determined that the environmental state of the environment in which the fuel cell is located is an abnormal state; wherein the frequency of the first alternating current signal is the dry-sensitive frequency, and the frequency of the second alternating current signal is the wet-sensitive frequency; A control module is used to control the target physical quantity corresponding to the target subsystem in response to the environmental state of the environment in which the fuel cell is located being an abnormal state, so that the environment in which the fuel cell is located reaches water balance, wherein the target subsystem includes a hydrogen subsystem, an air subsystem, and / or a cooling subsystem, the target physical quantity corresponding to the hydrogen subsystem includes air supply humidity and gas pressure, the target physical quantity corresponding to the air subsystem includes air supply humidity and gas flow, and the target physical quantity corresponding to the cooling subsystem includes cooling temperature.

7. A fuel cell system, characterized in that: The system includes a fuel cell, a fuel cell water balance control device, an AC impedance fixed frequency monitoring module and a target subsystem, wherein: The fuel cell water balance control device is used to implement the fuel cell water balance control method according to any one of claims 1-5.

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