A method and apparatus for assessing the health status of a fuel cell system

Abstract

This invention belongs to the field of fuel cell technology, specifically relating to a method and apparatus for assessing the health status of a fuel cell system. The method comprehensively considers the influence of various factors, including at least two relevant state factors from the stack health status, BOP health status, control status, and safety status, as well as the operating status, to establish a fuel cell system health evaluation system. Specifically, it multiplies the weighted sum of the scores for each relevant state with a health status coefficient determined based on the operating status score, and evaluates the fuel cell system health status based on the multiplication result. This improves the system fault diagnosis system, provides a more comprehensive and effective assessment of the fuel cell system's health status, and allows customers and after-sales personnel to have a more intuitive and comprehensive understanding of the fuel cell system's health status.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to a method and apparatus for assessing the health status of a fuel cell system. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are widely used in fuel cell vehicles due to their cleanliness and high energy efficiency. Currently, fuel cell systems primarily rely on setting fault thresholds for fault protection to ensure normal operation. However, many factors affect the normal operation of fuel cell systems, and many cannot be quantitatively analyzed, thus hindering real-time fault protection. Furthermore, there are no effective health assessment methods or monitoring systems for fuel cell systems. Therefore, it is impossible to accurately assess the current health status of the fuel cell system, thereby preventing timely warnings and the prevention of system failures.

[0003] Chinese invention patent application CN112784216A discloses a method for assessing the health of a proton exchange membrane fuel cell system. This method involves collecting fuel cell data during normal operation, determining its upper and lower limits and standard values, calculating the membership degree and weight of each parameter, and fusing the health status of multiple operating parameters to arrive at a system health assessment result. This patent primarily analyzes the operating parameters of the fuel cell system, i.e., the evaluation of the control state. However, besides the control state, other factors can also affect the health status of the fuel cell, leading to inaccurate health status assessments. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for assessing the health status of a fuel cell system, thereby solving the problem of inaccurate health status assessment of fuel cell systems in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution provided by this invention and the corresponding beneficial effects of the technical solution are as follows:

[0006] The present invention provides a method for assessing the health status of a fuel cell system, comprising the following steps:

[0007] 1) Obtain the states related to the health status assessment of the fuel cell system. The relevant states include at least two relevant state factors among the stack health status, BOP health status, control status, and safety status, and determine the relevant state score corresponding to each relevant state factor. Among them, the BOP health status considers the power consumption of the components in the fuel cell system, the control status considers the control accuracy of the fuel cell system, and the safety status considers the insulation performance and / or hydrogen concentration of the fuel cell system.

[0008] 2) Based on the weights corresponding to each relevant state, the scores of each relevant state are weighted and summed.

[0009] 3) Obtain the operating status of the fuel cell system, which takes into account the frequency of fuel cell system failures, and determine the operating status score corresponding to the operating status; determine the health status coefficient based on the operating status score;

[0010] 4) Multiply the weighted summation result obtained in step 2) with the health status coefficient obtained in step 3), and evaluate the health status of the fuel cell system based on the product result.

[0011] The beneficial effects of the above technical solution are as follows: This invention comprehensively considers the influence of various factors, including at least two related state factors among stack health status, BOP health status, control status and safety status, as well as operating status, to establish a fuel cell system health evaluation system and improve the system fault judgment system. It not only realizes the quantitative assessment of the health status of the fuel cell system, but also more comprehensively and effectively assesses the health status of the fuel cell system, so that customers and after-sales personnel can have a more intuitive and comprehensive understanding of the health status of the fuel cell system.

[0012] Further, in step 1), the relevant status score corresponding to the stack health status is the stack health status score; the stack health status includes at least two stack health status factors among voltage decay rate, voltage decay rate change rate, and single-cell consistency; wherein, the voltage decay rate is the ratio of the actual voltage of the fuel cell to the factory voltage; the voltage decay rate change rate is the derivative of the actual voltage of the fuel cell with respect to time;

[0013] The process of determining the stack health status score includes: determining the stack health status factor score corresponding to each stack health status factor; and weighting and summing the stack health status factor scores according to the weights corresponding to each stack health status factor to obtain the stack health status score. Among these factors, the higher the voltage decay rate, the lower the factor score corresponding to the voltage decay rate; the higher the voltage decay rate change rate, the lower the factor score corresponding to the voltage decay rate change rate; and the better the single-cell consistency, the higher the factor score corresponding to the single-cell consistency.

[0014] Further, in step 1), the relevant status score corresponding to the BOP health status is the BOP health status score; the BOP health status includes at least two BOP health status factors among air compressor power consumption deviation, water pump power consumption deviation, and hydrogen circulation pump power consumption deviation; wherein, the air compressor power consumption deviation is the deviation between the actual power consumption of the air compressor and the standard power consumption under set conditions; the water pump power consumption deviation is the deviation between the actual power consumption of the water pump and the standard power consumption under set conditions; and the hydrogen circulation pump power consumption deviation is the deviation between the actual power consumption of the hydrogen circulation pump and the standard power consumption under set conditions.

[0015] The process of determining the BOP health status score includes: determining the BOP health status factor score corresponding to each BOP health status factor; and weighting and summing the scores of each BOP health status factor according to their respective weights to obtain the BOP health status score. Specifically, the larger the power consumption deviation of the air compressor, the lower the factor score corresponding to the air compressor power consumption deviation; the larger the power consumption deviation of the water pump, the lower the factor score corresponding to the water pump power consumption deviation; and the larger the power consumption deviation of the hydrogen circulation pump, the lower the factor score corresponding to the hydrogen circulation pump power consumption deviation.

[0016] Further, in step 1), the relevant state score corresponding to the control state is the control state score; the control state includes at least two control state factors selected from power control accuracy deviation, hydrogen pressure control accuracy deviation, air pressure control accuracy deviation, flow control accuracy deviation, and temperature control accuracy deviation; wherein, the power control accuracy deviation is the deviation between the actual response power and the target power, the hydrogen pressure control accuracy deviation is the deviation between the actual response hydrogen pressure and the target hydrogen pressure, the air pressure control accuracy deviation is the deviation between the actual response air pressure and the target air pressure, the flow control accuracy deviation is the deviation between the actual response air flow rate and the target flow rate, and the temperature control accuracy deviation is the deviation between the actual response fuel cell temperature and the target temperature;

[0017] The process of determining the control state score includes: determining the control state factor score corresponding to each control state factor; and weighting and summing the control state factor scores according to the weights corresponding to each control state factor to obtain the control state score. Specifically, the larger the hydrogen pressure control accuracy deviation, the lower the factor score corresponding to the hydrogen pressure control accuracy deviation; the larger the air pressure control accuracy deviation, the lower the factor score corresponding to the air pressure control accuracy deviation; the larger the flow rate control accuracy deviation, the lower the factor score corresponding to the flow rate control accuracy deviation; and the larger the temperature control accuracy deviation, the lower the factor score corresponding to the temperature control accuracy deviation.

[0018] Further, in step 3), the relevant status score corresponding to the safety status is the safety status score; the safety status includes at least one safety status factor among insulation status and hydrogen concentration;

[0019] The process of determining the safety status score includes: determining the safety status factor score corresponding to each safety status factor; and weighting and summing the safety status factor scores according to the weights corresponding to each safety status factor to obtain the safety status score.

[0020] The insulation state includes at least one insulation state factor among insulation class and conductivity, and the process of determining the safety state factor score corresponding to the insulation state includes: determining the insulation state factor score corresponding to each insulation state factor; and weighting and summing the insulation state factor scores according to the weights corresponding to each insulation state factor score to obtain the safety state factor score corresponding to the insulation state.

[0021] The higher the insulation class, the higher the insulation status factor score corresponding to the insulation class; the greater the conductivity, the lower the insulation status factor score corresponding to the conductivity; the greater the hydrogen concentration, the lower the safety status factor score corresponding to the hydrogen concentration.

[0022] Furthermore, in step 3), the operating status includes at least one of the following operating status factors: cumulative days of failure and cumulative number of failures.

[0023] The process of determining the operating status score includes: determining the operating status factor score corresponding to each operating status factor; and weighting and summing the operating status factor scores according to the weights corresponding to each operating status factor to obtain the operating status score. Among these factors, the more days the faults have occurred cumulatively, the lower the factor score corresponding to the number of days the faults have occurred; the more times the faults have occurred cumulatively, the lower the factor score corresponding to the number of times the faults have occurred; and the higher the operating status score, the greater the health status coefficient.

[0024] Furthermore, the insulation class includes the insulation class of the positive electrode of the fuel cell and the insulation class of the negative electrode of the fuel cell.

[0025] Furthermore, after obtaining the relevant status scores and operating status scores, the process also includes a step of determining whether the fuel cell system needs maintenance based on the scores of the relevant status scores and operating status scores: if the scores of the relevant status scores and operating status scores are all greater than or equal to the set standard scores, then the fuel cell system does not need maintenance; otherwise, the fuel cell system needs maintenance.

[0026] Furthermore, after obtaining the health status score corresponding to the health status of the fuel cell stack, the process also includes a step of determining whether the fuel cell stack needs to be replaced based on the score of the health status score: if the health status score is greater than or equal to the set passing score for the fuel cell stack, then the fuel cell stack does not need to be replaced; otherwise, the fuel cell stack needs to be replaced.

[0027] The present invention provides a fuel cell system health status assessment device, comprising a memory and a processor. The processor is used to execute computer instructions stored in the memory to implement the fuel cell system health status assessment method described above, and to achieve the same beneficial effects as the method. Attached Figure Description

[0028] Figure 1 This is a flowchart of the fuel cell system health status assessment method of the present invention;

[0029] Figure 2 This is a structural diagram of the fuel cell system health status assessment device of the present invention. Detailed Implementation

[0030] The health status of a fuel cell system is not merely a matter of controlling operating parameters. With increasing operating environment and duration, the performance of the fuel cell stack, the performance of BOP components such as the air compressor, and the system's insulation all gradually change. While the fuel cell system may still operate without faults, its health status will be affected and gradually decline. Therefore, this invention, based on the factors influencing the healthy operation of a fuel cell system and comprehensively considering real-time operating status and trends, establishes a fuel cell system health status evaluation system. This system consists of five secondary indices: stack health status, BOP health status, system control status, system safety status, and system operating status. By monitoring the fuel cell health status, risks in the fuel cell system can be identified in advance and addressed promptly, effectively improving the reliability and durability of the fuel cell system.

[0031] Based on this, the following detailed description of a fuel cell system health status assessment method and a fuel cell system health status assessment device of the present invention, in conjunction with the accompanying drawings and embodiments, is provided.

[0032] Method Implementation Examples:

[0033] An embodiment of the fuel cell system health status assessment method of the present invention, the overall process of which is as follows: Figure 1 As shown, the process is as follows:

[0034] Step one: The fuel cell system acquires parameters such as current, voltage, operating voltage, operating temperature, air compressor speed, and air compressor power consumption through the fuel cell controller, and transmits the collected operating data to the big data server via the vehicle's T-BOX. The big data server performs differential and normalization analyses on the acquired data to evaluate the fuel cell system status; the specific processing steps are detailed in steps two through nine. In this embodiment, the states related to the fuel cell system health status assessment include stack health status, BOP health status, control status, and safety status.

[0035] Step two: Based on the data obtained in step one, calculate the fuel cell stack health status score β1. The fuel cell stack health status considers the single-cell consistency, voltage decay rate, and voltage decay rate of change. The specific process for calculating the fuel cell stack health status score is as follows:

[0036] 1) Obtain the standard deviation (or variance) of the voltage of a single cell during fuel cell operation, as well as the voltage V2 corresponding to polarization curve 2 on the same day and the voltage V1 corresponding to polarization curve 1 at 25% rated current (25% rated current is just an example).

[0037] 2) Calculate the voltage attenuation rate k = (V1 - V2) / V1, and determine the attenuation rate score β corresponding to the voltage attenuation rate k. 11 Generally, a 20% decay rate is considered the end-of-life condition for a fuel cell system. At this point, the fuel cell system's performance deteriorates significantly and energy consumption increases, but it can still function normally. Therefore, in this embodiment, a 20% decay rate corresponds to a passing score of 60 points, a 0% decay rate corresponds to a perfect score of 100 points, and a 100% decay rate corresponds to a score of 0 points. Other decay rates can be obtained through interpolation. For example, interpolation results in a 10% decay rate score of 80 points and an 80% decay rate score of 15 points. Of course, custom settings are also possible. For example, a (0%, 5%) decay rate score of 90 points can be set, (5%, 13%) a decay rate score of 80 points, (13%, 20%) a decay rate score of 70 points, (20%, 30%) a decay rate score of 50 points, and so on.

[0038] 3) Calculate the rate of change of voltage decay v = dV² / dt, and determine the decay rate score β corresponding to the rate of change of voltage decay v. 12 The higher the rate of change of voltage decay, the worse the health of the fuel cell stack. Therefore, the higher the rate of change of voltage decay, the lower the corresponding decay rate change score should be. In this embodiment, the voltage decay rate change rate v and the decay rate change score β are set. 12 The correspondence between them is β 12 =100-25000*v 2 That is, when v = 0, β 12 When β = 100 and v = 0.01, 12 =97.5, v=0.02, β 12 =90.

[0039] 4) Calculate the single-cell consistency S. Using the fuel cell single-cell voltage information collected by the inspection module, calculate the single-cell voltage variance, standard deviation, and range (maximum value - minimum value). Any existing method for evaluating single-cell consistency can be used to determine single-cell consistency, and a consistency score β corresponding to the single-cell consistency is determined based on the single-cell consistency. 13 The smaller the variance, standard deviation, and range, the better the consistency and the better the health of the fuel cell stack. Therefore, the better the consistency of a single cell, the higher the corresponding consistency score should be set.

[0040] 5) Based on the attenuation rate score β 11 β score of decay rate change 12 and consistency score β 13 The corresponding weights are used to perform a weighted summation to calculate the stack health status score β1. In this embodiment, the score is set to be the same as the decay rate score β1. 11 β score of decay rate change 12 and consistency score β 13 With corresponding weights of 0.5, 0.25, and 0.25, the stack health status score β1 is: β1 = 0.5 * β 11 +0.25*β 12 +0.25*β 13 .

[0041] Step 3: Based on the data obtained in Step 1, calculate the BOP health status score β2. BOP health status considers the power consumption of the air compressor, hydrogen circulation pump, and water pump. The specific process for calculating the BOP health status score is as follows:

[0042] 1) The air compressor is installed on the air intake pipeline of the fuel cell system. Based on the air compressor's operating speed, flow rate, and temperature, the standard power consumption and actual power consumption under standard conditions are obtained. The standard power consumption and actual power consumption are compared to obtain the deviation Δ11 between the two. The air compressor score β is determined based on the range of power consumption deviation of the air compressor within the deviation Δ11. 21 Different power consumption deviation ranges for air compressors are set, and each air compressor power consumption deviation range corresponds to an air compressor score β. 21 Furthermore, the greater the deviation in air compressor power consumption, the lower the air compressor score.

[0043] 2) The hydrogen circulation pump is a hydrogen circulation pump installed on the hydrogen circulation pipeline in the battery system. Based on the operating speed, flow rate, and temperature of the hydrogen circulation pump, the standard power consumption and actual power consumption under standard conditions are obtained. The standard power consumption and actual power consumption are compared to obtain the deviation Δ12 between the two. The hydrogen circulation pump score β is determined based on the range of power consumption deviation of the hydrogen circulation pump within the deviation Δ12. 22 Different power consumption deviation ranges for hydrogen circulation pumps are set, and each power consumption deviation range corresponds to a hydrogen circulation pump score β. 22 Furthermore, the greater the deviation in power consumption of the hydrogen circulation pump, the lower the hydrogen circulation pump score.

[0044] 3) The water pump is installed on the drainage pipeline of the battery system. Based on the water pump's operating speed, flow rate, and temperature, the standard power consumption and actual power consumption under standard conditions are obtained. The standard power consumption and actual power consumption are compared to obtain the deviation Δ13 between the two. The water pump score β is determined based on the range of power consumption deviation within which the deviation Δ13 falls. 23 Different water pump power consumption deviation ranges are set, and each water pump power consumption deviation range corresponds to a water pump score β. 23 Furthermore, the greater the deviation in water pump power consumption, the lower the water pump score.

[0045] 4) Based on the air compressor rating β 21 Hydrogen circulation pump rating β 22 and water pump rating β 23 The corresponding weights are used to perform a weighted summation to calculate the BOP health status score β2. In this embodiment, the score is set to be the same as the air compressor score β2. 21 Hydrogen circulation pump rating β 22 and water pump rating β 23 The corresponding weights are 0.35, 0.35, and 0.3, respectively. Therefore, the BOP health status score β2 is: β2 = 0.35 * β 21 +0.35*β 22 +0.3*β 23 .

[0046] Step four: Calculate the control state score β3 based on the data obtained in step one. The control state considers power control accuracy, hydrogen pressure control accuracy, air pressure control accuracy, flow control accuracy, and temperature control accuracy. The specific process for calculating the control state score is as follows:

[0047] 1) Determine the hydrogen pressure control accuracy deviation, which refers to the deviation between the actual response hydrogen pressure and the target hydrogen pressure. Obtain the deviation Δ21 between the actual response hydrogen pressure and the target hydrogen pressure under the set conditions. Determine the hydrogen pressure control accuracy score β based on the hydrogen pressure control deviation range within which the deviation Δ21 falls. 31 Different hydrogen pressure control deviation ranges are set, and each hydrogen pressure control deviation range corresponds to a hydrogen pressure control accuracy score β. 31 Furthermore, the greater the deviation in hydrogen pressure control, the lower the hydrogen pressure control accuracy score.

[0048] 2) Determine the air pressure control accuracy deviation, which refers to the deviation between the actual response air pressure and the target air pressure. Obtain the deviation Δ22 between the actual response air pressure and the target air pressure under the set conditions, and determine the air pressure control accuracy score β based on the air pressure control deviation range within which the deviation Δ22 falls. 32Different air pressure control deviation ranges are set, and each air pressure control deviation range corresponds to an air pressure control accuracy score β. 32 Furthermore, the greater the air pressure control deviation, the lower the air pressure control accuracy score.

[0049] 3) Determine the flow control accuracy deviation. Flow control accuracy deviation refers to the deviation between the actual response airflow and the target flowflow. Obtain the deviation Δ23 between the actual response airflow and the target flowflow under the set conditions. Determine the flow control accuracy score β based on the flow control deviation range within which the deviation Δ23 falls. 33 Different flow control deviation ranges are set, and each flow control deviation range corresponds to a flow control accuracy score β. 33 Furthermore, the greater the flow control deviation, the lower the flow control accuracy score.

[0050] 4) Determine the temperature control accuracy deviation. Temperature control accuracy deviation refers to the deviation between the actual response fuel cell temperature and the target temperature. Obtain the deviation Δ24 between the actual response fuel cell temperature and the target temperature under the set conditions. Determine the temperature control accuracy score β based on the temperature control deviation range within which the deviation Δ24 falls. 34 Different temperature control deviation ranges are set, and each temperature control deviation range corresponds to a temperature control accuracy score β. 34 Furthermore, the greater the temperature control deviation, the lower the temperature control accuracy score.

[0051] 5) Determine the power control accuracy deviation, which refers to the deviation between the actual response power and the target power. Obtain the deviation Δ25 between the actual response power and the target power under the set conditions. Determine the power control accuracy score β based on the power control deviation range within which the deviation Δ25 falls. 35 Different power control deviation ranges are set, and each power control deviation range corresponds to a power control accuracy score β. 35 Furthermore, the greater the power control deviation, the lower the power control accuracy score.

[0052] 6) Based on the hydrogen pressure control accuracy score β 31 Air compressor control accuracy score β 32 Flow control accuracy score β 33 Temperature control accuracy score β 34 Power control accuracy score β 35 The corresponding weights are weighted and summed to calculate the control state score β3. In this embodiment, the score is set to be the same as the hydrogen pressure control accuracy score β3. 31 Air compressor control accuracy score β 32 Flow control accuracy score β 33Temperature control accuracy score β 34 Power control accuracy score β 35 The corresponding weights are 0.2, 0.2, 0.2, 0.2, and 0.2, respectively. Therefore, the control state score β3 = 0.2 * β 31 +0.2*β 32 +0.2*β 33 +0.2*β 34 +0.2*β 35 .

[0053] Step 5: Calculate the safety status score β4 based on the data obtained in Step 1. The safety status considers the insulation state of the battery system and the hydrogen concentration. The specific process for calculating the safety status score β4 is as follows:

[0054] 1) Obtain the daily operating data of the fuel cell system, including conductivity, insulation class and hydrogen concentration, and sort these three parameters in order of magnitude. Use the value at the 95th percentile as the conductivity, insulation class and hydrogen concentration of the fuel cell system, and then perform subsequent processing.

[0055] 2) The insulation class is the ratio of the fuel feedback insulation value to the fuel cell voltage. ① The insulation classes of both the positive and negative electrodes are calculated simultaneously. The higher the insulation class, the better the insulation state of the battery system. Therefore, the higher the insulation class, the higher the corresponding insulation class score. In this embodiment, referring to the insulation design requirements of fuel cell vehicles, 300Ω / V and 100Ω / V are used as benchmarks. Then: if the insulation classes of both the positive and negative electrodes are ≥300Ω / V, the insulation class score β... 411 The score is 100; if both are <100Ω / V, then the edge rating β is... 411 The score is 0; if one insulation class is ≥300Ω / V and the other insulation class is ≥100Ω / V and <300Ω / V, then the insulation class score β is... 411 The score is between 80 and 100 points; the specific value can be set directly or calculated through interpolation based on the actual situation. If both insulation classes meet the requirements of ≥100Ω / V and <300Ω / V, then the insulation class score β is... 411 The score is between 60 and 80 points; the specific value can be set directly or calculated through interpolation based on the actual situation. Based on this relationship, the insulation class score β can be calculated. 411 ② Obtain the conductivity. Higher conductivity indicates poorer insulation performance of the battery system; therefore, higher conductivity corresponds to a lower conductivity score. Based on this relationship, the conductivity score β corresponding to the conductivity can be obtained. 412 ③Based on the insulation class rating β 411 Conductivity score β 412 The insulation status score β is calculated by weighting and summing the corresponding weights. 41In this embodiment, the insulation class rating β is set. 411 Conductivity score β 412 The corresponding weights are 0.8 and 0.2, respectively, then the insulation status score β 41 For: β 41 =0.8*β 411 +0.2*β 412 .

[0056] 3) Based on the hydrogen concentration c, determine the hydrogen concentration score β corresponding to hydrogen concentration c. 42 The higher the hydrogen concentration, the worse the safety condition. Therefore, the higher the hydrogen concentration, the lower the corresponding hydrogen concentration score should be. In this embodiment, a hydrogen concentration of 1% is set as the passing score of 60 points, a hydrogen concentration of 2% corresponds to a hydrogen concentration score of 0 points, and the scores corresponding to other hydrogen concentrations can be obtained by interpolation.

[0057] 4) Based on the insulation condition score β 41 Hydrogen concentration score β 42 The corresponding weights are used to perform a weighted summation to calculate the safety status score β4. In this embodiment, the score is set to be the same as the insulation status score β4. 41 Hydrogen concentration score β 42 The corresponding weights are all 0.5, so the safety status score β4 is: β4 = 0.5 * β 41 +0.5*β 42 .

[0058] Step Six: Based on the data obtained in Step One, calculate the operating status score β5; and determine the health status coefficient K based on the operating status score β5. The operating status considers the frequency of fuel cell system failures, including the cumulative number of failures and the cumulative number of days since the failures occurred. The specific process for calculating the operating status score β5 is as follows:

[0059] 1) Determine the fault day score K corresponding to the cumulative number of fault occurrences D. 11 The more days a fault occurs cumulatively, the lower the operational status score. Therefore, the more days a fault occurs cumulatively, the higher the fault day score (K) should be. 11 The lower the value. In this embodiment, the cumulative number of days of failure D and the failure day score K are set. 11 The correspondence between them is shown in Table 1. The fault day score when the cumulative number of fault occurrences is 6 to 9 can be calculated by interpolation, and the fault day score when the cumulative number of fault occurrences is greater than or equal to 10 is 0.

[0060] Table 1. Rating of Cumulative Days of Fault Occurrence

[0061] Total number of days since the fault occurred No fault occurred 1 2 3 4 5 10 Failure Days Rating 100 99 96 91 84 75 0

[0062] 2) Determine the fault count score K corresponding to the cumulative number of faults R. 12 The more times a fault occurs cumulatively, the lower the operational status score. Therefore, the higher the cumulative number of faults, the higher the fault count score K should be. 12 The lower the value. In this embodiment, the cumulative number of fault occurrences R and the fault days score K are set. 12 The correspondence between them is shown in Table 2. The fault count scores when the cumulative number of fault occurrences is 2-5, 5-10, 10-15, and 15-20 can be calculated by interpolation. The fault count score when the cumulative number of fault occurrences is greater than or equal to 20 is 0.

[0063] Table 2. Rating of Cumulative Number of Fault Occurrences

[0064] Total number of faults ≤2 5 10 15 20 Fault count rating 100 80 60 20 0

[0065] 3) Based on the score K for the number of days of downtime 11 Fault frequency score K 12 The corresponding weights are used to perform a weighted summation to calculate the operating status score β5. In this embodiment, the score is set to be related to the number of fault days score K. 11 Fault frequency score K 12 The corresponding weights are 0.7 and 0.3, respectively. Therefore, the running status score β5 is: β5 = 0.7 * K 11 +0.3*K 12 .

[0066] 4) Calculate the ratio of the operating status score β5 to 100, and the result is the health status coefficient K.

[0067] Step 7: Compare and determine whether the fuel cell system requires maintenance by comparing the stack health status score β1 calculated in Step 2, the BOP health status score β2 calculated in Step 3, the control status score β3 calculated in Step 4, the safety status score β4 calculated in Step 5, and the operating status score β5 calculated in Step 6.

[0068] If β1≥80, β2≥80, β3≥80, β4≥80, and β5≥80 are satisfied, then the fuel cell system is in a healthy state and does not require maintenance.

[0069] If any of β1, β2, β3, β4, or β5 is less than 80, it indicates that the fuel cell system is in poor health and requires maintenance. If β1 is less than 60, the fuel cell stack needs to be replaced.

[0070] Step 8: Based on the determined stack health status weights Q1, BOP health status weights Q2, control status weights Q3, and safety status weights Q4, and the stack health status scores β1, BOP health status scores β2, control status scores β3, and safety status scores β4 determined in Steps 2 to 6, and the health status coefficient K, calculate the fuel cell system health status assessment result according to the following formula:

[0071] γ=K*(Q1*β1+Q2*β2+Q3*β3+Q4*β4)*100%

[0072] Wherein, γ represents the health status of the fuel cell system. The weight allocation in this formula is primarily determined based on the influence of various factors affecting the fuel cell system and the maintenance cost. In this embodiment, the weights for the stack health status (Q1), BOP health status (Q2), control status (Q3), and safety status (Q4) are set as follows: Q1 = 0.5, Q2 = 0.25, Q3 = 0.1, and Q4 = 0.15, respectively.

[0073] Step nine involves displaying the results obtained in steps seven and eight through monitoring interfaces, instruments, mobile apps, etc., and pushing this information to customers and after-sales service personnel when it is found that the fuel cell needs maintenance or has a low health status, so as to promptly handle after-sales issues related to the fuel cell system.

[0074] It should be noted that all weights in this embodiment are not fixed and can be adjusted according to the actual situation and importance. Furthermore, all scores in this embodiment are based on a 100-point scale. As other implementation methods, a 10-point scale, a 1000-point scale, or other scoring systems can be chosen, as long as all scores are determined according to a single standard.

[0075] In this embodiment, to achieve a comprehensive assessment of the fuel cell system's health status, numerous factors are considered. For example, the fuel cell system health γ formula considers four relevant states: stack health status, BOP health status, control status, and safety status. Furthermore, the stack health status considers three factors: stack cell consistency, voltage decay rate, and voltage decay rate change rate. The BOP health status considers the power consumption deviations of three components: the air compressor, hydrogen circulation pump, and water pump, and so on. In other embodiments, the fuel cell system health γ formula may consider only two or three of the factors from stack health status, BOP health status, control status, and safety status. The stack health status may consider two of the factors from stack cell consistency, voltage decay rate, and voltage decay rate change rate, and so on. These factors can be reduced based on their importance. Of course, other factors affecting fuel cell health can also be added.

[0076] In this embodiment, the stack health status score β1, BOP health status score β2, control status score β3, safety status score β4, and operating status score β5 are calculated in the order of steps two to six, respectively. However, in practice, these scores may not be calculated in this order, and if the big data server allows, they can be performed simultaneously. Furthermore, the order of steps seven and eight can be reversed or performed simultaneously.

[0077] In summary, this method has the following characteristics: 1) It comprehensively considers various influencing factors to establish a fuel cell system health evaluation system, improves the system fault judgment system, and more comprehensively and effectively assesses the health status of the fuel cell system, enabling customers and after-sales personnel to have a more intuitive and comprehensive understanding of the fuel cell system's health status. 2) It relies on a big data platform for data processing and analysis, analyzes the changing trends of various states of the fuel cell system in real time, promptly detects faults that the fuel cell system controller itself cannot set, identifies risks in advance, improves the reliability and durability of the fuel cell system, and effectively reduces the fuel cell system failure rate and losses caused by failures. 3) Health status and maintenance requirements can be transmitted to customers and after-sales personnel through instruments or mobile apps, facilitating maintenance.

[0078] Device Example:

[0079] An embodiment of the fuel cell system health status assessment device of the present invention, such as... Figure 2 As shown, the system includes an onboard remote terminal, a memory, a processor, and an internal bus. Operating data of the fuel cell system is transmitted to the memory via the onboard remote terminal. The processor and memory communicate and interact with each other via the internal bus. The memory includes at least one software function module stored in the memory. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby implementing the fuel cell system health status assessment method described in the embodiments of this invention.

[0080] The processor can be a microprocessor (MCU), a programmable logic device (FPGA), or other processing devices. The memory can be any type of memory that stores information using electrical energy, such as RAM and ROM; it can also be any type of memory that stores information using magnetic energy, such as hard disks, floppy disks, magnetic tapes, magnetic core memory, bubble memory, and USB flash drives; it can also be any type of memory that stores information using optical methods, such as CDs and DVDs; and of course, it can also be other types of memory, such as quantum memory and graphene memory.

Claims

1. A method of fuel cell system health state assessment, characterized by, The method comprises the following steps: 1) obtaining states related to fuel cell system health state evaluation, the related states comprising at least two related state factors in a heap health state, a BOP health state, a control state and a safety state, and determining a related state score corresponding to each related state factor; wherein the BOP health state considers the power consumption of components in the fuel cell system, the control state considers the control accuracy of the fuel cell system, and the safety state considers the insulation performance and / or hydrogen concentration of the fuel cell system; 2) performing weighted summation of the related state scores according to the weights corresponding to each related state; 3) obtaining an operating state of the fuel cell system, which considers the occurrence frequency of fuel cell system failures, and comprises at least one operating state factor in a fault cumulative occurrence day D and a fault cumulative occurrence number R; The operating state score corresponding to the operating state is determined in the following manner: determining an operating state factor score corresponding to each operating state factor; the more D, the lower the factor score corresponding to D; the more R, the lower the factor score corresponding to R; performing weighted summation of the operating state factor scores according to the weights corresponding to each operating state factor to obtain the operating state score; determining a health state coefficient K according to the operating state score; the higher the operating state score, the greater K; 4) multiplying the weighted summation result obtained in step 2) by K to evaluate the health state of the fuel cell system.

2. The fuel cell system health state evaluation method according to claim 1, characterized by, In step 1), the related state score corresponding to the heap health state is a heap health state score; the heap health state comprises at least two heap health state factors in a voltage decay rate, a voltage decay rate change rate and a single piece consistency; wherein the voltage decay rate is the ratio of the actual voltage of the fuel cell to the factory voltage; the voltage decay rate change rate is the derivative of the actual voltage of the fuel cell with respect to time; The process of determining the heap health state score comprises: determining a heap health state factor score corresponding to each heap health state factor; performing weighted summation of the heap health state factor scores according to the weights corresponding to each heap health state factor to obtain the heap health state score; wherein the greater the voltage decay rate, the lower the factor score corresponding to the voltage decay rate; the greater the voltage decay rate change rate, the lower the factor score corresponding to the voltage decay rate change rate; the better the single piece consistency, the higher the factor score corresponding to the single piece consistency.

3. The fuel cell system health state evaluation method according to claim 1, characterized by, In step 1), the related state score corresponding to the BOP health state is a BOP health state score; the BOP health state comprises at least two BOP health state factors in an air compressor power consumption deviation, a water pump power consumption deviation and a hydrogen circulating pump power consumption deviation; wherein the air compressor power consumption deviation is the deviation of the actual power consumption of the air compressor from the standard power consumption under the set conditions; the water pump power consumption deviation is the deviation of the actual power consumption of the water pump from the standard power consumption under the set conditions; the hydrogen circulating pump power consumption deviation is the deviation of the actual power consumption of the hydrogen circulating pump from the standard power consumption under the set conditions; The process of determining the BOP health state score comprises: determining a BOP health state factor score corresponding to each BOP health state factor; and performing weighted summation on the BOP health state factor scores according to weights corresponding to the BOP health state factors to obtain the BOP health state score; wherein the greater the air compressor power consumption deviation, the lower the factor score corresponding to the air compressor power consumption deviation; the greater the water pump power consumption deviation, the lower the factor score corresponding to the water pump power consumption deviation; and the greater the hydrogen circulating pump power consumption deviation, the lower the factor score corresponding to the hydrogen circulating pump power consumption deviation.

4. The fuel cell system health state evaluation method according to claim 1, characterized by, In step 1), the relevant state score corresponding to the control state is a control state score; the control state comprises at least two control state factors of power control accuracy deviation, hydrogen pressure control accuracy deviation, air pressure control accuracy deviation, flow control accuracy deviation, and temperature control accuracy deviation; wherein the power control accuracy deviation is a deviation between an actual response power and a target power, the hydrogen pressure control accuracy deviation is a deviation between an actual response hydrogen pressure and a target hydrogen pressure, the air pressure control accuracy deviation is a deviation between an actual response air pressure and a target air pressure, the flow control accuracy deviation is a deviation between an actual response air flow and a target flow, and the temperature control accuracy deviation is a deviation between an actual response fuel cell temperature and a target temperature. The process of determining the control state score comprises: determining a control state factor score corresponding to each control state factor; and performing weighted summation on the control state factor scores according to weights corresponding to the control state factors to obtain the control state score; wherein the greater the hydrogen pressure control accuracy deviation, the lower the factor score corresponding to the hydrogen pressure control accuracy deviation; the greater the air pressure control accuracy deviation, the lower the factor score corresponding to the air pressure control accuracy deviation; the greater the flow control accuracy deviation, the lower the factor score corresponding to the flow control accuracy deviation; and the greater the temperature control accuracy deviation, the lower the factor score corresponding to the temperature control accuracy deviation.

5. The fuel cell system health state evaluation method according to claim 1, characterized by, In step 3), the relevant state score corresponding to the safety state is a safety state score; the safety state comprises at least one safety state factor of insulation state and hydrogen concentration. The process of determining the safety state score comprises: determining a safety state factor score corresponding to each safety state factor; and performing weighted summation on the safety state factor scores according to weights corresponding to the safety state factors to obtain the safety state score. The insulation state comprises at least one insulation state factor of insulation level and conductivity, and the process of determining the safety state factor score corresponding to the insulation state comprises: determining an insulation state factor score corresponding to each insulation state factor; and performing weighted summation on the insulation state factor scores according to weights corresponding to the insulation state factor scores to obtain the safety state factor score corresponding to the insulation state. The higher the insulation level, the higher the insulation state factor score corresponding to the insulation level; the greater the conductivity, the lower the insulation state factor score corresponding to the conductivity; and the greater the hydrogen concentration, the lower the safety state factor score corresponding to the hydrogen concentration.

6. The fuel cell system health state evaluation method according to claim 5, characterized by, The insulation levels include an insulation level of a fuel cell positive electrode and an insulation level of a fuel cell negative electrode.

7. The fuel cell system health state evaluation method according to any one of claims 1 to 6, characterized by, After obtaining the respective correlation state scores and the operation state score, the method further comprises a step of determining whether the fuel cell system needs maintenance according to the score values of the respective correlation state scores and the operation state score: if the score values of the respective correlation state scores and the operation state score are all greater than or equal to a set standard score value, the fuel cell system does not need maintenance; otherwise, the fuel cell system needs maintenance.

8. The fuel cell system health state evaluation method according to any one of claims 1 to 6, characterized by, After obtaining the health state score corresponding to the stack health state, the method further comprises a step of determining whether the fuel cell stack needs replacement according to the score value of the health state score: if the health state score is greater than or equal to a set stack passing score, the fuel cell stack does not need replacement; otherwise, the fuel cell stack needs replacement.

9. A fuel cell system health state evaluation device characterized by comprising: The fuel cell system health state evaluation method comprises a memory and a processor, and the processor is used to execute computer instructions stored in the memory to realize the fuel cell system health state evaluation method according to any one of claims 1-8.

Images