Fuel cell system air supply control method and device based on altitude correction

Abstract

The invention provides a fuel cell system air supply control method and device based on altitude correction, and relates to the field of proton exchange membrane fuel cell system control, and the method comprises the following steps: calculating and measuring an altitude height value; fitting an air compressor MAP under a standard environment through a model data parameter identification technology; acquiring a historical estimated altitude value, and calculating a correction starting switch; determining whether the current fuel cell system starts an altitude correction function or not; if the altitude correction function is enabled, acquiring state data of the current fuel cell system, and setting a weight coefficient in combination with a correction enabling switch; and performing data fusion to obtain a weighted current altitude, performing table look-up, and calculating the rotating speed of an air compressor and the opening degree of a tail exhaust valve so as to control the air supply of the fuel cell system. And the control error of the air supply system caused by altitude environment factors is corrected by low-cost equipment.

Description

Technical Field

[0001] The present application relates to the field of proton exchange membrane fuel cell system control, and in particular to a fuel cell system air supply control method and device based on altitude correction. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) systems are widely used in transportation due to their obvious advantages such as high energy conversion efficiency and low pollution emissions. Among them, the air supply system provides PEMFC with oxygen required for electrochemical reactions to ensure PEMFC's high reaction efficiency and safe operating conditions. However, the changing use environment makes the air supply system more affected by atmospheric pressure and ambient temperature. Especially at higher altitudes, the lower intake pressure and temperature make the air compressor more prone to surge, resulting in poor output performance of PEMFC or even failure. The traditional altitude correction method is to add a dedicated atmospheric pressure sensor to the system to determine the current altitude, and then correct the operating conditions of the air supply system, but this increases the complexity and cost of the system.

[0003] For example, Chinese patent CN115657486A relates to an OER predictive control method for a fuel cell air supply system under variable altitude conditions. The atmospheric pressure sensor collects parameters such as atmospheric pressure, and calculates an ideal OER value with the maximum net output power as the optimization goal; predictive control is carried out based on the difference between the ideal OER value and the current OER value and the safe operating range of the fuel cell.

[0004] Therefore, there is an urgent need for an air supply method for a fuel cell system without adding an additional atmospheric pressure sensor to meet the use requirements of PEMFC in different altitude environments and ensure its adaptability and reliability. Summary of the invention

[0005] The purpose of the present invention is to provide a fuel cell system air supply control method and device based on altitude correction in order to solve the problem that a conventional fuel cell system air supply method based on altitude correction needs to add an atmospheric pressure sensor, which leads to system complexity and excessive cost.

[0006] The above-mentioned purpose of the present application is achieved through the following technical solutions: S1: During the startup phase of the fuel cell system, the current ambient pressure is measured by the air inlet pressure sensor. And the air inlet pressure value , calculate the measured altitude value ; Fit the MAP diagram of the air compressor under standard environment through model data parameter identification technology; S2: Calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram and the current estimated altitude ; S3: Get historical estimated altitude values , calculate the correction enable switch to determine whether the altitude correction function of the current fuel cell system is enabled; S4: If the altitude correction function is enabled, obtain the current fuel cell system status data, combine the correction enable switch, and set the weight coefficient ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; S5: Current altitude after weighting A table is looked up to calculate the corrected air compressor speed and tail exhaust valve opening; the air supply of the fuel cell system is controlled by the air compressor speed and tail exhaust valve opening.

[0007] Optionally, step S1 includes: The temperature of the standard environment is set to 25°C and the air pressure is set to 1 standard atmosphere; Based on the test data of fuel cell system suppliers and vehicle manufacturers, the least squares fitting is performed to obtain the air compressor MAP diagram as follows:

[0008] in is the air compressor pressure ratio, expressed as , is the air inlet pressure value of the inlet pressure sensor, For the current environmental pressure; is the air compressor speed.

[0009] Optionally, step S2 includes: Sensor data includes: Current ambient temperature , Air inlet pressure value , air intake mass flow And the current air compressor speed ; By current ambient temperature and current environmental pressures , get the temperature correction coefficient and pressure correction factor ; The temperature correction factor is expressed as , is the current ambient temperature in Kelvin ; The pressure correction factor is expressed as , is the current environmental pressure, in units of ; By temperature correction factor and pressure correction factor , the air intake mass flow Corrected to standard air intake mass flow rate under standard conditions ,as follows:

[0010] in, To correct the air intake mass flow to the standard operating conditions, Collect real-time air intake mass flow for the sensor; Get the current air compressor speed ; Through the standard air intake mass flow and current air compressor speed , combined with the air compressor MAP diagram, calculate the current pressure ratio and the current estimated altitude .

[0011] Optionally, step S3 includes: S31: During the fuel cell startup phase, the altitude value will be measured The current estimated altitude Compare and get the relative error value; If the relative error value does not exceed the preset percentage, it means the current estimated altitude value Reasonable, enable altitude correction function, output weight Q; If the relative error value exceeds the preset percentage, it means the current estimated altitude value It is unreasonable to not enable the altitude correction function; S32: During the fuel cell operation phase, the measured altitude is discarded Value, get history k historical estimated altitude values ​​stored in time ,in , is the sampling calculation period, is a preset positive integer; like It indicates the current estimated altitude value Unreasonable, do not enable the altitude correction function, among which, Indicates the preset maximum altitude change value, The function is used to find the absolute value of data; represents the rate of change of the estimated value during the fuel cell operation phase; like It indicates the current estimated altitude value Reasonable, enable altitude correction function; The correction enabling switch is the flag of the relative error value and the flag of the estimated value change rate.

[0012] Optionally, step S4 includes: The data estimation and fusion part is solved by the pressure-altitude correspondence function, and its formula is:

[0013] in, is the atmospheric pressure corresponding to different altitudes, in kPa; is the atmospheric pressure at an altitude of 0 meters, in kPa; is the current altitude, in m; During the fuel cell startup phase, the first step of the data fusion formula is:

[0014] in is the weight coefficient set during the fuel cell startup phase; During the continuous operation of the fuel cell, the formula for data fusion is as follows:

[0015] in, is the weighted correction value of the current altitude; Indicates the weight coefficient set during the continuous operation phase of the fuel cell, , weight coefficient The value range of ,and .

[0016] Optionally, step S5 includes: Get the current stack current of the fuel cell system ; By current altitude and stack current , get the corrected air compressor speed and tail valve opening , expressed as:

[0017] in, and They are the corrected air compressor speed and tail exhaust valve opening respectively.

[0018] A fuel cell system air supply control device based on altitude correction, the device comprising: Data acquisition module, data processing module, fuel cell control module; The data acquisition module is used to obtain sensor data and measure the altitude value. , historical estimated altitude values , current status data of the fuel cell system; The data processing module is used to fit the MAP diagram of the air compressor under the standard environment through the model data parameter identification technology; The data processing module is also used to calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram. and the current estimated altitude ; The data processing module is also used to measure the altitude value And historical estimated altitude values , calculate the correction enable switch to determine whether the altitude correction function of the current fuel cell system is enabled; The data processing module is also used to enable the altitude correction function, and to set the weight coefficient in combination with the correction enable switch and the current state data of the fuel cell system. ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; The data processing module is also used to calculate the current altitude through weighted Look up the table to calculate the corrected air compressor speed and tail valve opening; The fuel cell control module is used to control the air supply of the fuel cell system through the corrected air compressor speed and tail exhaust valve opening.

[0019] A computer-readable storage medium stores instructions, which, when executed, perform an air supply control method for a fuel cell system based on altitude correction.

[0020] The beneficial effects of the technical solution provided by this application are: This application estimates and fuses data based on the data of each sensor, corrects the air supply system control error caused by altitude environmental factors, improves the environmental adaptability and reliability of fuel cell vehicles, does not require additional atmospheric pressure sensors, and reduces system costs. The fuel cell system air supply control method of this application is expressed as the original control form + altitude correction control form, and the altitude correction value can be augmented as a measurable disturbance. Therefore, the technical solution of this application does not change the original air supply system control solution, and has better portability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 is a flow chart in an embodiment of the present application; Figure 2 is a schematic diagram of the air path topology in an embodiment of the present application; Figure 3 It is the algorithm logic diagram in the embodiment of the present application; Figure 4 It is a device module diagram in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described in detail with reference to the accompanying drawings.

[0023] An embodiment of the present application provides an air supply control method for a fuel cell system based on altitude correction.

[0024] Please refer to Figure 1 , Figure 1 : is a flow chart of a fuel cell system air supply control method based on altitude correction in an embodiment of the present application, including: S1: During the startup phase of the fuel cell system, the current ambient pressure is measured by the air inlet pressure sensor. And the air inlet pressure value , calculate the measured altitude value ; Fit the MAP diagram of the air compressor under standard environment through model data parameter identification technology; Step S1 includes: The temperature of the standard environment is set to 25°C and the air pressure is set to 1 standard atmosphere; Based on the test data of fuel cell system suppliers and vehicle manufacturers, the least squares fitting is performed to obtain the air compressor MAP diagram as follows:

[0025] in is the air compressor pressure ratio, expressed as , is the air inlet pressure value of the inlet pressure sensor, For the current environmental pressure; is the air compressor speed.

[0026] Specifically, measure the altitude value The altitude is measured only once during the startup phase and is used as the subsequent estimated altitude value. The initial value of ; in subsequent stages, it will not be used This value, measured by the air inlet pressure sensor, will be used as the inlet pressure value use.

[0027] Specifically, during the startup phase of the fuel cell system, the air inlet pressure sensor is connected to the atmospheric environment to obtain the measured altitude value. , specifically including: The fuel cell system receives the start command, opens the throttle and tail valve, connects the air inlet pressure sensor to the atmosphere, and reads the data of the air inlet pressure sensor and records it as ; By formula ,in, is the atmospheric pressure corresponding to different altitudes, in kPa; is the atmospheric pressure at an altitude of 0 meters, in kPa; is the current altitude, in m; calculate the measured altitude value .

[0028] S2: Calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram and the current estimated altitude ; Step S2 includes: Sensor data includes: Current ambient temperature , Air inlet pressure value , air intake mass flow And the current air compressor speed ; By current ambient temperature and current environmental pressures , get the temperature correction coefficient and pressure correction factor ; The temperature correction factor is expressed as , is the current ambient temperature in Kelvin ; The pressure correction factor is expressed as , is the current environmental pressure, in units of ; By temperature correction factor and pressure correction factor , the air intake mass flow rate Corrected to standard air intake mass flow rate under standard conditions ,as follows:

[0029] in, To correct the air intake mass flow to the standard operating conditions, Collect real-time air intake mass flow for the sensor; Get the current air compressor speed ; Through the standard air intake mass flow and current air compressor speed , combined with the air compressor MAP diagram, calculate the current pressure ratio and the current estimated altitude .

[0030] In this application, The acquisition is divided into two modes according to the stage of the fuel cell. The first mode is that the fuel cell is in the startup stage. The pressure ratio is obtained by opening the throttle and tail valve at the same time to connect the air inlet pressure sensor to the atmosphere, and then measuring it through the air inlet pressure sensor. The second mode is when the fuel cell is in normal operation, and the pressure ratio is obtained by calculating the air compressor MAP diagram and the air inlet mass flow rate. , air inlet pressure during operation The pressure ratio is measured in real time by the air inlet pressure sensor. and air inlet pressure It is known that By formula Obtained by reverse push.

[0031] S3: Get the measured altitude value And historical estimated altitude values , calculating the estimated value change rate; determining whether the altitude correction function of the current fuel cell system is enabled; Step S3 includes: S31: During the fuel cell startup phase, the altitude value will be measured The current estimated altitude Compare and get the relative error value; If the relative error value does not exceed the preset percentage, it means the current estimated altitude value Reasonable, enable altitude correction function, output weight Q; If the relative error value exceeds the preset percentage, it means the current estimated altitude value It is unreasonable to not enable the altitude correction function; S32: During the fuel cell operation phase, the measured altitude is discarded Value, get history k historical estimated altitude values ​​stored in time ,in , is the sampling calculation period, is a preset positive integer; Specifically, since the air compressor is always in operation, the measured altitude value cannot be obtained. At this time, use the timer and memory module to record the k stored in the past n*T time. data.

[0032] like It indicates the current estimated altitude value Unreasonable, do not enable the altitude correction function, among which, Indicates the preset maximum altitude change value, The function is used to find the absolute value of data; represents the rate of change of the estimated value during the fuel cell operation phase; like It indicates the current estimated altitude value Reasonable, enable altitude correction function; The correction enabling switch is the flag of the relative error value and the flag of the estimated value change rate.

[0033] S4: If the altitude correction function is enabled, the current status data of the fuel cell system is obtained, and the weight coefficient is set in combination with the estimated value change rate. ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; Step S4 includes: The data estimation and fusion part is solved by the pressure-altitude correspondence function, and its formula is:

[0034] in, is the atmospheric pressure corresponding to different altitudes, in kPa; is the atmospheric pressure at an altitude of 0 meters, in kPa; is the current altitude, in m; During the fuel cell startup phase, the first step of the data fusion formula is:

[0035] in is the weight coefficient set during the fuel cell startup phase; During the continuous operation of the fuel cell, the formula for data fusion is as follows:

[0036] in, is the weighted correction value of the current altitude; Indicates the weight coefficient set during the continuous operation phase of the fuel cell, , weight coefficient The value range of ,and .

[0037] Specifically, the correction judgment module sets the data fusion weight coefficient by judging the current state of the fuel cell system, the estimated value change rate, and the feasibility. The current altitude calculated by the data fusion unit , as the output current altitude value, calculate the current altitude The atmospheric pressure under the atmosphere is fed back to the environmental factor correction module for iterative calculation. When the PEMFC is in operation, the data fusion unit will output the correction value of the current altitude. and environmental pressure , and iteratively compute updates.

[0038] S5: Current altitude after weighting A table is looked up to calculate the corrected air compressor speed and tail exhaust valve opening; the air supply of the fuel cell system is controlled by the air compressor speed and tail exhaust valve opening.

[0039] Step S5 includes: Get the current stack current of the fuel cell system ; By current altitude and stack current , get the corrected air compressor speed and tail valve opening , expressed as:

[0040] in, and They are the corrected air compressor speed and tail exhaust valve opening respectively.

[0041] Specifically, the correction value table is used to obtain the current altitude through parameter calibration With current Correction compensation value of air compressor speed and tail valve opening under the condition , The correction compensation value is input into the air supply control system to achieve robust control of air supply in different altitude environments.

[0042] Specifically, the air path topology is shown as follows: Figure 2 After obtaining the corresponding table lookup function, write the control logic for online use. The control logic is as follows Figure 3 shown.

[0043] Please refer to Figure 4 , Figure 4 : is a module diagram of an air supply control device for a fuel cell system based on altitude correction in an embodiment of the present application, the device comprising: Data acquisition module, data processing module, fuel cell control module; The data acquisition module is used to obtain sensor data and measure the altitude value. , historical estimated altitude values , current status data of the fuel cell system; The data processing module is used to fit the MAP diagram of the air compressor under the standard environment through the model data parameter identification technology; The data processing module is also used to calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram. and the current estimated altitude ; The data processing module is also used to measure the altitude value And historical estimated altitude values , calculate the correction enable switch to determine whether the altitude correction function of the current fuel cell system is enabled; The data processing module is also used to enable the altitude correction function, and to set the weight coefficient in combination with the correction enable switch and the current state data of the fuel cell system. ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; The data processing module is also used to calculate the current altitude through weighted Look up the table to calculate the corrected air compressor speed and tail valve opening; The fuel cell control module is used to control the air supply of the fuel cell system through the corrected air compressor speed and tail exhaust valve opening.

[0044] The present application also discloses a computer-readable storage medium storing a plurality of instructions, wherein the instructions are suitable for a processor to load to execute the above-mentioned fuel cell system air supply control method based on altitude correction.

[0045] The above are only exemplary embodiments of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification, those skilled in the art will easily think of other embodiments of the present disclosure.

[0046] This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art not described in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A fuel cell system air supply control method based on altitude correction, characterized in that: The method comprises the following steps: S1: During the startup phase of the fuel cell system, the current ambient pressure is measured by the air inlet pressure sensor. And the air inlet pressure value , calculate the measured altitude value ; Fit the MAP diagram of the air compressor under standard environment through model data parameter identification technology; S2: Calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram and the current estimated altitude ; S3: Get historical estimated altitude values , calculate the correction enable switch to determine whether the altitude correction function is enabled for the current fuel cell system; S4: If the altitude correction function is enabled, obtain the current fuel cell system status data, combine the correction enable switch, and set the weight coefficient ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; S5: Current altitude after weighting A table is looked up to calculate the corrected air compressor speed and tail exhaust valve opening; the air supply of the fuel cell system is controlled by the air compressor speed and tail exhaust valve opening.

2. The method for controlling air supply of a fuel cell system based on altitude correction according to claim 1, characterized in that: Step S1 includes: The temperature of the standard environment is set to 25°C and the air pressure is set to 1 standard atmosphere; Based on the test data of fuel cell system suppliers and vehicle manufacturers, the least squares fitting is performed to obtain the air compressor MAP diagram as follows: in is the air compressor pressure ratio, expressed as , is the air inlet pressure value of the inlet pressure sensor, For the current environmental pressure; is the air compressor speed.

3. The method for controlling air supply of a fuel cell system based on altitude correction according to claim 1, characterized in that: Step S2 includes: Sensor data includes: Current ambient temperature , Air inlet pressure value , air intake mass flow And the current air compressor speed ; By current ambient temperature and current environmental pressures , obtain the temperature correction coefficient and pressure correction factor ; The temperature correction factor is expressed as , is the current ambient temperature in Kelvin ; The pressure correction factor is expressed as , is the current environmental pressure, in units of ; By temperature correction factor and pressure correction factor , the air intake mass flow Corrected to standard air intake mass flow rate under standard conditions ,as follows: in, To correct the air intake mass flow to the standard operating conditions, Collect real-time air intake mass flow for the sensor; Get the current air compressor speed ; Through the standard air intake mass flow and current air compressor speed , combined with the air compressor MAP diagram, calculate the current pressure ratio and the current estimated altitude .

4. The method for controlling air supply of a fuel cell system based on altitude correction according to claim 1, characterized in that: Step S3 includes: S31: During the fuel cell startup phase, the altitude value will be measured The current estimated altitude Compare and get the relative error value; If the relative error value does not exceed the preset percentage, it means the current estimated altitude value Reasonable, enable altitude correction function, output weight Q; If the relative error value exceeds the preset percentage, it means the current estimated altitude value It is unreasonable to not enable the altitude correction function; S32: During the fuel cell operation phase, the measured altitude is discarded Value, get history k historical estimated altitude values ​​stored in time ,in , is the sampling calculation period, is a preset positive integer; like It indicates the current estimated altitude value Unreasonable, do not enable the altitude correction function, among which, Indicates the preset maximum altitude change value, The function is used to find the absolute value of data; represents the rate of change of the estimated value during the fuel cell operation phase; like It indicates the current estimated altitude value Reasonable, enable altitude correction function; The correction enabling switch is the flag of the relative error value and the flag of the estimated value change rate.

5. The method for controlling air supply of a fuel cell system based on altitude correction according to claim 1, characterized in that: Step S4 includes: The data estimation and fusion part is solved by the pressure-altitude correspondence function, and its formula is: in, is the atmospheric pressure corresponding to different altitudes, in kPa; is the atmospheric pressure at an altitude of 0 meters, in kPa; is the current altitude, in m; During the fuel cell startup phase, the first step of the data fusion formula is: in is the weight coefficient set during the fuel cell startup phase; During the continuous operation of the fuel cell, the formula for data fusion is as follows: in, is the weighted correction value of the current altitude; Indicates the weight coefficient set during the continuous operation phase of the fuel cell, , weight coefficient The value range of ,and .

6. The method for controlling air supply of a fuel cell system based on altitude correction according to claim 1, characterized in that: Step S5 includes: Get the current stack current of the fuel cell system ; By current altitude and stack current , get the corrected air compressor speed and tail valve opening , expressed as: in, and They are the corrected air compressor speed and tail exhaust valve opening respectively.

7. A fuel cell system air supply control device based on altitude correction, used to implement a fuel cell system air supply control method based on altitude correction as claimed in any one of claims 1 to 6, characterized in that: The device includes: Data acquisition module, data processing module, fuel cell control module; The data acquisition module is used to obtain sensor data and measure the altitude value. , historical estimated altitude values , current status data of the fuel cell system; The data processing module is used to fit the MAP diagram of the air compressor under the standard environment through the model data parameter identification technology; The data processing module is also used to calculate the current pressure ratio by combining the collected sensor data with the air compressor MAP diagram. and the current estimated altitude ; The data processing module is also used to measure the altitude value And historical estimated altitude values , calculate the correction enable switch to determine whether the altitude correction function is enabled for the current fuel cell system; The data processing module is also used to enable the altitude correction function, and to set the weight coefficient in combination with the correction enable switch and the current state data of the fuel cell system. ; Through the weight coefficient , the measured altitude is and the current estimated altitude , perform data fusion and obtain the weighted current altitude ; The data processing module is also used to calculate the current altitude through weighted Look up the table to calculate the corrected air compressor speed and tail valve opening; The fuel cell control module is used to control the air supply of the fuel cell system through the corrected air compressor speed and tail exhaust valve opening.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed by a computer, the method according to any one of claims 1 to 6 is executed.

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