Fuel cell test fixture temperature control method and system based on dynamic PID optimization

Abstract

The invention relates to a fuel cell test fixture temperature control method and system based on dynamic PID optimization, and the method comprises the steps: obtaining a target working temperature and a temperature uniformity threshold value of a fuel cell test fixture, dividing the target working temperature and the temperature uniformity threshold value into a plurality of heating temperature difference intervals, and configuring differentiated PID initial parameters for each heating temperature difference interval; synchronously acquiring temperature data of a plurality of areas of the fuel cell test fixture in real time, and calculating the overall average temperature of the fixture and local temperature differences among the areas; judging whether the current state is in an overall heating demand state or an overall cooling demand state, and judging whether local temperature compensation is needed or not based on the relationship between the local temperature difference and a temperature uniformity threshold value; and the dynamic PID parameter corresponding to the current heating temperature difference interval is finely adjusted periodically according to the overall temperature fluctuation and the local temperature difference condition in the temperature control process.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and in particular to a method and system for temperature control of fuel cell test fixtures based on dynamic PID optimization. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are widely used in the new energy field. As a core component, the accuracy of the membrane electrode assembly (MEA) performance test results directly affects the overall fuel cell development efficiency and reliability. In MEA performance testing, external heating is required to stabilize the operating temperature of the fuel cell single-cell test fixture at a set value to meet the testing requirements.

[0003] Currently, external heating methods for fuel cell fixtures mainly fall into two categories: one is to achieve heating and heat preservation by heating the liquid, and the other is to use electric heaters, such as electric heating rods or electric heating plates, to achieve heating and heat preservation using the Ohmic heating effect. The core logic of existing electric heating temperature control technology is as follows: Temperature sensors collect the fixture temperature value in real time, and a PID algorithm is used to adjust the output power of the electric heater based on the difference between the current temperature and the set temperature, thereby achieving rapid heating and heat preservation.

[0004] However, this existing technology has significant drawbacks in practical applications. Due to the inherent hysteresis of heat conduction and the large amount of heat generated by the membrane electrode during operation, relying solely on temperature difference and PID regulation for temperature control makes it difficult to respond to temperature changes in real time. This often leads to the fixture operating temperature exceeding the set value and difficulty in cooling down, making it impossible to achieve precise control of the fixture temperature and thus affecting the accuracy of membrane electrode performance testing.

[0005] In summary, there is currently a lack of a method and system for temperature control of fuel cell test fixtures to solve or partially solve the aforementioned problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a method and system for controlling the temperature of a fuel cell test fixture based on dynamic PID optimization, so as to achieve dynamic and accurate temperature control of different areas of the fuel cell test fixture.

[0007] The objective of this invention can be achieved through the following technical solutions: One aspect of the present invention provides a temperature control method for a fuel cell test fixture based on dynamic PID optimization, comprising the following steps: The target operating temperature and temperature uniformity threshold of the fuel cell test fixture are obtained, and multiple heating temperature difference intervals are divided. Differentiated PID initial parameters are configured for each heating temperature difference interval. Real-time synchronous acquisition of temperature data from multiple areas of the fuel cell test fixture, calculation of the overall average temperature of the fixture and the local temperature difference between each area; Based on the relationship between the overall average temperature and the target operating temperature, it is determined whether the current state is one of overall heating demand or overall cooling demand. Based on the relationship between the local temperature difference and the temperature uniformity threshold, it is determined whether local temperature compensation is required. If the overall heating demand is met, the basic heating power is calculated by calling the corresponding dynamic PID parameters based on the heating temperature difference range to which the overall average temperature belongs; if it is determined that local temperature compensation is required, additional heating compensation power is applied to the corresponding area according to the direction of the local temperature difference. If the overall cooling demand is met, the basic cooling power is calculated based on the pre-acquired membrane electrode discharge current; if it is determined that local temperature compensation is required, additional cooling compensation power is applied to the corresponding area according to the direction of the local temperature difference. The dynamic PID parameters corresponding to the current heating temperature difference range are periodically fine-tuned based on the overall temperature fluctuation and local temperature difference during the temperature control process.

[0008] As a preferred technical solution, the heating temperature difference range is divided into a large temperature difference range, a medium temperature difference range, and a small temperature difference range. In the large temperature difference range, the initial PID parameter proportional coefficient is greater than the reference value, and the integral coefficient is less than the reference value. In the small temperature difference range, the initial PID parameter proportional coefficient is less than the reference value, and the integral coefficient is greater than the reference value. In the medium temperature difference range, the initial PID parameter proportional coefficient and integral coefficient are both close to or equal to the reference value.

[0009] As a preferred technical solution, applying additional heating compensation power to the corresponding area includes: When the local temperature difference exceeds the temperature uniformity threshold and the temperature of the core test area is lower than that of the edge area, the heating power of the core test area is increased. When the local temperature difference exceeds the temperature uniformity threshold and the temperature of the edge area is lower than that of the core test area, the heating power of the edge area is increased.

[0010] As a preferred technical solution, the basic cooling power is calculated using the following formula: in, Based on cooling power, The preset cooling coefficient, This represents the discharge current of the membrane electrode.

[0011] As a preferred technical solution, the fine-tuning of the dynamic PID parameters corresponding to the current heating temperature difference range includes the following steps: If the overall temperature fluctuation continues to exceed the preset stable threshold, adjust the proportional coefficient and / or integral coefficient of the current PID parameters. If the local temperature difference remains close to but does not exceed the temperature uniformity threshold, the current PID parameters remain unchanged.

[0012] Another aspect of the present invention provides a fuel cell test fixture temperature control system based on dynamic PID optimization, used to implement the aforementioned fuel cell test fixture temperature control method, the system comprising: The initialization configuration module is used to set the target operating temperature and temperature uniformity threshold of the fuel cell test fixture, divide the heating temperature difference range, and configure the dynamic PID parameters for each range. The data acquisition and processing module is used to synchronously acquire temperature data from temperature sensors arranged in multiple areas of the fixture, and calculate the overall average temperature of the fixture and the local temperature difference between each area. The status judgment module is used to determine the overall temperature control requirement status and local compensation requirements based on the overall average temperature and the local temperature difference between each region. The control execution module is used to perform corresponding interval dynamic PID power calculation and / or local compensation power output based on the output of the state judgment module.

[0013] As a preferred technical solution, the control execution module includes: The power calculation unit is used to calculate the basic heating power or basic cooling power by calling the corresponding dynamic PID parameters according to the heating temperature difference range to which the overall average temperature belongs. The local compensation unit is used to calculate and output additional heating or cooling compensation power to the target area based on the direction of the local temperature difference when local compensation is required.

[0014] As a preferred technical solution, the local compensation unit is configured to output enhanced heating power to the core test area heater when the core test area temperature is lower than the edge area temperature; and to output enhanced heating power to the edge area heater when the edge area temperature is lower than the core test area temperature.

[0015] As a preferred technical solution, the following are also included: The PID parameter optimization module is used to monitor the temperature control effect at fixed intervals and dynamically fine-tune the PID parameters corresponding to the currently effective heating temperature difference range based on overall temperature fluctuations and local temperature differences.

[0016] In another aspect, an electronic device is provided, including one or more processors, a memory, and one or more programs stored in the memory, said one or more programs including instructions for executing the aforementioned dynamic PID-optimized fuel cell test fixture temperature control method.

[0017] Compared with the prior art, the present invention has at least one of the following beneficial effects: (1) The temperature can be adjusted to the target working temperature quickly and smoothly: The present invention divides the heating process into at least three temperature difference intervals based on the difference between the overall average temperature of the fixture and the target temperature through system initialization preset. Differentiated dynamic PID parameters are configured for each interval. A larger proportional coefficient and a smaller integral coefficient are configured for the large temperature difference interval to accelerate the heating. A smaller and a larger coefficient are configured for the small temperature difference interval to achieve precise fine-tuning and suppress overshoot. This realizes rapid response in the early stage of the heating process and stable and precise control when approaching the target temperature, effectively shortening the stabilization time of the test fixture to reach the set working temperature, while reducing temperature overshoot and fluctuation near the steady-state working point.

[0018] (2) Achieving coordinated control that ensures efficiency through overall regulation and uniformity through local compensation: This invention uses temperature sensors arranged in multiple areas, such as the core and edge areas of the fixture, to collect data synchronously, calculate and monitor local temperature differences in real time. When the local temperature difference exceeds a preset uniformity threshold, the state judgment module triggers a local compensation mechanism. The local compensation submodule in the regulation execution module applies additional heating or cooling compensation power to specific areas based on whether the core or edge area is too cold. The overall temperature control base power is calculated by the PID controller for each interval. While ensuring that the fixture reaches the target temperature quickly and stably, this invention can proactively and specifically eliminate or reduce temperature differences between areas, controlling the temperature difference between the core test area and the edge area within a certain range, thus improving the temperature uniformity of the fixture's working plane.

[0019] (3) Imparting self-learning and adaptive capabilities to the control system: This invention not only adopts initial interval PID parameters, but also sets up a dynamic optimization mechanism. The PID parameter optimization module monitors the overall temperature fluctuation amplitude and local temperature difference trend at a fixed period. Based on the monitoring results, for example, when the small temperature difference interval frequently overshoots, the Kp or Ki value of the current interval is finely adjusted. When the local temperature difference continues to approach the threshold but the overall temperature control is stable, the PID parameters are kept unchanged first, and the uniformity is mainly maintained by local compensation. It can dynamically optimize key control parameters according to the actual temperature control effect during operation, so that the system has stronger robustness to internal parameter drift and external operating condition disturbances. Attached Figure Description

[0020] Figure 1 This is a flowchart of the fuel cell test fixture temperature control method based on dynamic PID optimization in the embodiment. Figure 2 This is a schematic diagram of the fuel cell test fixture temperature control system based on dynamic PID optimization in the embodiment. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0022] Example 1 To address the problems existing in the prior art, this embodiment provides a fuel cell test fixture temperature control method based on dynamic PID optimization. The fuel cell single cell test fixture has independent heating and cooling components, and high-precision temperature sensors are arranged at the contact position with the membrane electrode, which is the core test area, and at the auxiliary structure, which is the edge area.

[0023] See Figure 1 The method includes the following steps: Step S1: Obtain the target operating temperature and temperature uniformity threshold of the fuel cell test fixture, divide it into multiple heating temperature difference intervals, and configure differentiated PID initial parameters for each heating temperature difference interval.

[0024] The user sets the target operating temperature T0=80℃ and the temperature uniformity threshold ΔT through the human-machine interface. unif =0.5℃. The system automatically divides the heating temperature difference into three zones based on T0 and configures dynamic PID initial parameters for each zone, with a base coefficient K0=100.

[0025] 1. Large temperature difference range.

[0026] T0-Tc avg ≥5℃, meaning the overall average temperature is below 75℃. The preset parameter is the proportionality coefficient K. p =1.2×K0=120, integral coefficient K i =0.8×K0=80.

[0027] 2. Medium temperature difference range.

[0028] 1℃≤T0-Tc avg <5℃, meaning the overall average temperature is between 75℃ and 79℃. The preset parameter is K. p =1.0×K0=100, K i =1.0×K0=100.

[0029] 3. Small temperature difference range.

[0030] T0-Tc avg <1℃, meaning the overall average temperature is above 79℃. The preset parameter is K. p=0.6×K0 = 60, K i =1.2×K0 = 120。

[0031] Preset cooling coefficient K cool = 50 W / A。

[0032] Step S2, synchronously and real-time collect the temperature data of multiple areas of the fuel cell test fixture, and calculate the overall average temperature of the fixture and the local temperature difference between areas.

[0033] The system synchronously collects the temperature Tc1 of the core test area at a period of 10 ms, for example, read from sensor A. At the same time, collect the temperature Tc2 of the edge area, for example, read from sensor B. In addition, it is also necessary to collect the real-time discharge current Ic of the membrane electrode, which can be collected from the test bench.

[0034] At a sampling moment, it is measured that Tc1 = 70.2 °C, Tc2 = 69.8 °C, and Ic = 0 A.

[0035] After that, the data processing unit immediately calculates the overall average temperature Tc avg =(70.2 + 69.8) / 2 = 70.0 °C, and the local temperature difference ΔTc = |70.2 - 69.8| = 0.4 °C After that, it is judged that the temperature difference of 0.4 °C is less than the set abnormal data rejection threshold of 2 °C, and the data is valid.

[0036] Step S3, based on the relationship between the overall average temperature and the target working temperature, judge the current overall heating demand state or overall cooling demand state, and based on the relationship between the local temperature difference and the temperature uniformity threshold, judge whether local temperature compensation is required.

[0037] The controller makes a judgment based on the calculation result of S2. First, make an overall temperature judgment, Tc avg (70.0 °C) < T0 (80 °C), it is determined that the current is in the overall heating demand state. After that, make a local temperature difference judgment ΔTc (0.4 °C) ≤ ΔT unif (0.5 °C), it is determined that the current local temperature difference is within the acceptable range, and there is no need to start local compensation for the time.

[0038] Step S4, if in the overall heating demand state, call the corresponding dynamic PID parameter to calculate the basic heating power according to the heating temperature difference interval where the overall average temperature belongs; if it is judged that local temperature compensation is required, apply additional heating compensation power to the corresponding area according to the local temperature difference direction.

[0039] Since it is in the overall heating demand state, and T0 - Tc avg = 10 °C, belonging to the large temperature difference interval. After that, calculate the basic heating power, and the system calls the PID parameter K of the large temperature difference interval p= 120, K i = 80, calculate the basic heating power P according to the PID algorithm heat_base . Assume that the cumulative value of the integral term of the current temperature error is Σe = 15, then: P heat_base = K p ×(T0 - Tc avg ) + K i ×Σe = 120×10 + 80×15 = 1200 + 1200 = 2400W. This power will be evenly applied to the overall heater of the fixture.

[0040] After heating for a period of time, at the new sampling period, Tc1 = 79.5°C, Tc2 = 78.5°C, Ic = 50A, and the membrane electrode starts to work and release heat. Tc avg =(79.5 + 78.5) / 2 = 79.0°C, ΔTc = |79.5 - 78.5| = 1.0°C.

[0041] At this point, re - judge the state. Overall, Tc avg (79.0°C) < T0(80°C), still in the overall heating demand state. T0 - Tc avg = 1.0°C, entering the small temperature difference range. Locally, ΔTc(1.0°C) > ΔT unif (0.5°C), local compensation is required. And because Tc1 > Tc2, it indicates that the edge area is colder.

[0042] After that, call the PID parameters K in the small temperature difference range p = 60, K i = 120, calculate P heat_bas , assume that Σe = 2 at this time, P heat_base = 60×1 + 120×2 = 60 + 240 = 300W.

[0043] Finally, perform local compensation. For the case where ΔTc > ΔT unif and Tc2 < Tc1, the system separately increases the compensation power of 10% for the edge - area heater, that is, an additional 300W×10% = 30W is provided. The core - area heater receives the allocated part of the basic power, while the edge - area heater receives its allocated part plus 30W of compensation.

[0044] Step S5, if in the overall cooling demand state, calculate the basic cooling power based on the pre - obtained discharge current of the membrane electrode; if it is judged that local temperature compensation is required, apply additional cooling compensation power to the corresponding area according to the local temperature difference direction.

[0045] Similar to step S4, perform the same calculation when the demand is for cooling.

[0046] Step S6: Periodically fine-tune the dynamic PID parameters corresponding to the current heating temperature difference range based on the overall temperature fluctuation and local temperature difference during the temperature control process.

[0047] As the temperature continued to rise, Tc was measured at another time. avg =80.2℃>T0, the system switches to the overall cooling demand state.

[0048] Calculate the basic cooling power P_ cool_base =K_ cool ×Ic=50×50=2500W.

[0049] If ΔTc still exceeds the limit and the core area is overheating (i.e., Tc1>Tc2), then an additional 15% compensation power of 375W will be provided to the core area cooler.

[0050] The system checks every 200ms. If it detects that the overall temperature fluctuates frequently between 79.9℃ and 80.3℃ with an amplitude >0.3℃ within a small temperature range, a slight overshoot is identified. In this case, a fine-tuning process is automatically performed, adjusting the K value within the current small temperature range. p Slightly reduced to 55, or K i The value was fine-tuned to 125 to optimize steady-state performance.

[0051] This method ensures the optimal control strategy for different temperature difference stages through "interval dynamic PID", and effectively suppresses regional temperature differences through "local-overall synergy", ultimately achieving fast, accurate and uniform temperature control of the fuel cell test fixture.

[0052] Example 2 Based on Example 1, this example provides a fuel cell test fixture temperature control system based on dynamic PID optimization, used to implement the fuel cell test fixture temperature control method of Example 1. See [link to example]. Figure 2 The system includes (1) Initialize the configuration module.

[0053] This is used to set the target operating temperature and temperature uniformity threshold of the fuel cell test fixture, divide the heating temperature difference range, and configure the dynamic PID parameters for each range.

[0054] (2) Data acquisition and processing module.

[0055] It is used to synchronously collect temperature data from temperature sensors arranged in multiple areas of the fixture, and to calculate the overall average temperature of the fixture and the local temperature difference between each area.

[0056] (3) Status judgment module.

[0057] It is used to determine the overall temperature control requirements and local compensation requirements based on the overall average temperature and the local temperature differences between different areas.

[0058] (4) Regulation and execution module, which is used to perform corresponding interval dynamic PID power calculation and / or local compensation power output based on the output of the status judgment module.

[0059] Specifically, the control execution module includes: 1. Power calculation unit.

[0060] For the heating temperature difference range to which the overall average temperature belongs, the corresponding dynamic PID parameters are called to calculate the basic heating power or basic cooling power.

[0061] 2. Local compensation unit.

[0062] It is used to calculate and output additional heating or cooling compensation power to the target area based on the direction of the local temperature difference when local compensation is required.

[0063] (5) PID parameter optimization module.

[0064] It is used to monitor the temperature control effect at fixed intervals and dynamically fine-tune the PID parameters corresponding to the currently effective heating temperature difference range based on overall temperature fluctuations and local temperature differences.

[0065] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for temperature control of a fuel cell test fixture based on dynamic PID optimization, characterized in that, Includes the following steps: The target operating temperature and temperature uniformity threshold of the fuel cell test fixture are obtained, and multiple heating temperature difference intervals are divided. Differentiated PID initial parameters are configured for each heating temperature difference interval. Real-time synchronous acquisition of temperature data from multiple areas of the fuel cell test fixture, calculation of the overall average temperature of the fixture and the local temperature difference between each area; Based on the relationship between the overall average temperature and the target operating temperature, it is determined whether the current state is one of overall heating demand or overall cooling demand. Based on the relationship between the local temperature difference and the temperature uniformity threshold, it is determined whether local temperature compensation is required. If the overall heating demand is met, the basic heating power is calculated by calling the corresponding dynamic PID parameters based on the heating temperature difference range to which the overall average temperature belongs; if it is determined that local temperature compensation is required, additional heating compensation power is applied to the corresponding area according to the direction of the local temperature difference. If the overall cooling demand is met, the basic cooling power is calculated based on the pre-acquired membrane electrode discharge current; if it is determined that local temperature compensation is required, additional cooling compensation power is applied to the corresponding area according to the direction of the local temperature difference. The dynamic PID parameters corresponding to the current heating temperature difference range are periodically fine-tuned based on the overall temperature fluctuation and local temperature difference during the temperature control process.

2. The method for temperature control of a fuel cell test fixture based on dynamic PID optimization according to claim 1, characterized in that, The heating temperature difference range is divided into a large temperature difference range, a medium temperature difference range, and a small temperature difference range. In the large temperature difference range, the initial PID parameter proportional coefficient is greater than the reference value, and the integral coefficient is less than the reference value. In the small temperature difference range, the initial PID parameter proportional coefficient is less than the reference value, and the integral coefficient is greater than the reference value. In the medium temperature difference range, the initial PID parameter proportional coefficient and integral coefficient are both close to or equal to the reference value.

3. The method for temperature control of a fuel cell test fixture based on dynamic PID optimization according to claim 1, characterized in that, The application of additional heating compensation power to the corresponding area includes: When the local temperature difference exceeds the temperature uniformity threshold and the temperature of the core test area is lower than that of the edge area, the heating power of the core test area is increased. When the local temperature difference exceeds the temperature uniformity threshold and the temperature of the edge area is lower than that of the core test area, the heating power of the edge area is increased.

4. The method for temperature control of a fuel cell test fixture based on dynamic PID optimization according to claim 1, characterized in that, The basic cooling power is calculated using the following formula: in, Based on cooling power, The preset cooling coefficient, This represents the discharge current of the membrane electrode.

5. The method for temperature control of a fuel cell test fixture based on dynamic PID optimization according to claim 1, characterized in that, The fine-tuning of the dynamic PID parameters corresponding to the current heating temperature difference range includes the following steps: If the overall temperature fluctuation continues to exceed the preset stable threshold, adjust the proportional coefficient and / or integral coefficient of the current PID parameters. If the local temperature difference remains close to but does not exceed the temperature uniformity threshold, the current PID parameters remain unchanged.

6. A temperature control system for a fuel cell test fixture based on dynamic PID optimization, characterized in that, For implementing the fuel cell test fixture temperature control method as described in any one of claims 1-5, the system comprises: The initialization configuration module is used to set the target operating temperature and temperature uniformity threshold of the fuel cell test fixture, divide the heating temperature difference range, and configure the dynamic PID parameters for each range. The data acquisition and processing module is used to synchronously acquire temperature data from temperature sensors arranged in multiple areas of the fixture, and calculate the overall average temperature of the fixture and the local temperature difference between each area. The status judgment module is used to determine the overall temperature control requirement status and local compensation requirements based on the overall average temperature and the local temperature difference between each region. The control execution module is used to perform corresponding interval dynamic PID power calculation and / or local compensation power output based on the output of the state judgment module.

7. The fuel cell test fixture temperature control system based on dynamic PID optimization according to claim 6, characterized in that, The control execution module includes: The power calculation unit is used to calculate the basic heating power or basic cooling power by calling the corresponding dynamic PID parameters according to the heating temperature difference range to which the overall average temperature belongs. The local compensation unit is used to calculate and output additional heating or cooling compensation power to the target area based on the direction of the local temperature difference when local compensation is required.

8. The fuel cell test fixture temperature control system based on dynamic PID optimization according to claim 7, characterized in that, The local compensation unit is configured to output enhanced heating power to the core test area heater when the core test area temperature is lower than the edge area temperature, and to output enhanced heating power to the edge area heater when the edge area temperature is lower than the core test area temperature.

9. The temperature control system for a fuel cell test fixture based on dynamic PID optimization according to claim 6, characterized in that, Also includes: The PID parameter optimization module is used to monitor the temperature control effect at fixed intervals and dynamically fine-tune the PID parameters corresponding to the currently effective heating temperature difference range based on overall temperature fluctuations and local temperature differences.

10. An electronic device, characterized in that, It includes one or more processors, a memory, and one or more programs stored in the memory, said one or more programs including instructions for executing the dynamic PID-optimized fuel cell test fixture temperature control method as described in any one of claims 1-5.

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