Method and system for controlling output current of fuel cell stack
By detecting differences in the output current of the fuel cell stack and controlling the actuator state adjustment, the delay problem when the output current of the fuel cell stack changes is solved, thus extending the lifespan of the fuel cell stack and battery cells.
Patent Information
- Application Number
- CN202411070163.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-06
- Publication Date
- 2026-02-06
AI Technical Summary
In existing technologies, when the output current of a fuel cell stack changes, there is a delay in the actuator state adjustment, which leads to a reduction in the stack's lifespan, especially in the battery cells at the bottom of the stack.
By detecting the current and desired output current values of the fuel cell stack, it is determined whether the difference or ratio exceeds a threshold, and the actuator is controlled to delay or directly adjust the output current change to avoid delay in actuator state change, including the regulation of hydrogen supply, air compressor, water separator, drain valve and hydrogen recirculation pump.
This effectively avoids the delay between actuator state changes and output current changes, extending the lifespan of the fuel cell stack and, in particular, the battery cells at the bottom of the stack.
Smart Images
Figure CN121484126A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cells. Specifically, it relates to a method and system for controlling the output current of a fuel cell stack. Background Technology
[0002] For fuel cells, when an increase in the desired output current or voltage (i.e., the output current or voltage requested by the load) is detected, the states of various actuators used to regulate the reaction conditions at the fuel cell stack need to be controlled accordingly. These actuators include: a hydrogen supply unit for supplying hydrogen to be reacted to the anode of the fuel cell stack; an air compressor for supplying oxygen to be reacted to the cathode of the fuel cell stack; a water separator for separating water from the anode reaction effluent; a drain and vent valve for discharging water and gas from the water separator; and optionally, a hydrogen recirculation pump for collecting hydrogen from the anode reaction effluent and recirculating it downstream of the hydrogen supply unit. In the prior art, when the desired output current increases, the output current of the fuel cell stack changes instantaneously from the current output current to the desired output current. However, the states of the aforementioned actuators do not instantly reach the state required to meet the desired output current, but are gradually regulated to the required state.
[0003] In other words, there is a "delay" between the change in the state of each actuator and the change in the output current. This "delay" is more pronounced for some battery cells at the bottom of the stack.
[0004] Therefore, there is a need for a method and system for controlling the output current of a fuel cell stack that should avoid the aforementioned "delay" phenomenon. Summary of the Invention
[0005] The applicant discovered that in the prior art, the phenomenon of a “delay” in the state of one or more actuators used to regulate the reaction conditions at the fuel cell stack relative to changes in output current negatively impacts the fuel cell stack lifespan, especially for battery cells located at the bottom of the stack, where the negative impact is exacerbated.
[0006] Therefore, the present invention proposes a method for controlling the output current of a fuel cell stack, comprising:
[0007] When an increased output current supply is requested from the fuel cell stack, the current output current value and the expected output current value of the fuel cell stack are obtained;
[0008] Control one or more actuators used to regulate the reaction conditions at the fuel cell stack so that one or more actuators reach the state required to achieve the desired output current value;
[0009] Determine whether the difference or ratio between the expected output current value and the current output current value exceeds the set threshold;
[0010] If it is determined that the difference or ratio exceeds a set threshold, the output current is controlled to delay the increase of the output current from the current value to the desired value, such that during or before the increase of the output current from the current value to the desired value, the states of one or more actuators required to obtain the desired output current value are satisfied; and
[0011] If it is determined that the difference or ratio does not exceed the set threshold, the output current is controlled to change directly from the current output current value to the desired output current value.
[0012] The set threshold is the absolute value of the difference between the desired output current value and the current output current value, or the ratio or reciprocal of the absolute value of the difference to the current output current value, or the ratio or reciprocal of the desired output current value to the current output current value.
[0013] Controlling multiple actuators includes controlling any one of the following or any combination thereof:
[0014] The hydrogen supply rate and pressure of the hydrogen supply unit in the fuel cell;
[0015] The air supply rate and pressure of the air compressor in the fuel cell;
[0016] The rate at which a fuel cell water separator separates water from the reaction effluent at the anode of the fuel cell stack;
[0017] The discharge rate of water and gas from the fuel cell's drain and vent valve from the water separator; and
[0018] The hydrogen recirculation pump of the fuel cell collects hydrogen from the reaction effluent at the anode of the stack and recirculates the hydrogen downstream to the hydrogen supply unit at a rate that allows it to be used for hydrogen recirculation.
[0019] The delay of increasing the output current from the current output current value to the desired output current value includes: controlling the output current to increase from the current output current value to the desired output current value after a set time period has elapsed since the detection of the request for increased output current supply from the stack, or controlling the output current to gradually increase from the current output current value to the desired output current value.
[0020] Controlling the output current to gradually increase from the current value to the desired value may include controlling the output current to increase from the current value in a linear manner in two or more segments until the desired value is reached, or controlling the output current to increase from the current value in an exponential manner until the desired value is reached.
[0021] The present invention also proposes a system for controlling the output current of a fuel cell stack, the system being configured to: when a request for an increased output current supply from the stack is detected, acquire the current output current value and the desired output current value of the stack, and the system includes:
[0022] An actuator control module is configured to receive a desired output current value and control one or more actuators for adjusting the reaction conditions at the fuel cell stack so that the one or more actuators reach the state required to achieve the desired output current value.
[0023] The judgment module is configured to receive the current output current value and the expected output current value, and to determine whether the difference or ratio between the expected output current value and the current output current value exceeds a set threshold.
[0024] A delay module, configured to receive the current output current value and the desired output current value, and control the output current to delay the increase of the output current from the current output current value to the desired output current value; and
[0025] The switching module is configured to receive the desired output current value and the output results of the judgment module and the delay module, and is further configured to:
[0026] If the output from the judgment module indicates that the difference or ratio between the expected output current value and the current output current value exceeds a set threshold, then the output current is set based on the output from the delay module; and
[0027] If the output received from the judgment module indicates that the difference or ratio between the desired output current value and the current output current value does not exceed the set threshold, then the output current is controlled to directly change from the current output current value to the desired output current value.
[0028] One or more of the actuators may include one or more of the following:
[0029] A hydrogen supply unit that supplies hydrogen to be reacted to the anode of the fuel cell stack;
[0030] An air compressor that supplies oxygen to be reacted to the cathode of the fuel cell stack;
[0031] A water separator used to separate water from the reaction effluent of the anode of a fuel cell stack;
[0032] A drain and vent valve for discharging water and gas from the water separator; and
[0033] Optionally, a hydrogen recirculation pump is used to collect hydrogen from the reaction effluent of the anode of the fuel cell stack and recirculate the hydrogen to the downstream of the hydrogen supply unit.
[0034] The present invention also proposes a computer program product comprising computer instructions that, when executed by a processor, implement the method according to the present invention. Attached Figure Description
[0035] The method and system for controlling the output current of a fuel cell stack according to the present invention will now be described in detail with reference to the accompanying drawings, in which:
[0036] Figure 1 This is a block diagram illustrating the principle of a method for controlling the output current of a fuel cell stack according to the present invention; and
[0037] Figure 2 This is a schematic diagram showing the actuators used to regulate the reaction conditions at the fuel cell stack. Detailed Implementation
[0038] In general, the method for controlling the output current of a fuel cell stack according to the present invention includes the following steps:
[0039] S101: When an increased output current supply is requested from the fuel cell stack, the current output current value and the desired output current value of the fuel cell stack are obtained.
[0040] S201: Control one or more actuators used to regulate the reaction conditions at the fuel cell stack so that one or more actuators reach the state required to achieve the desired output current value;
[0041] S301: Determine whether the difference or ratio between the expected output current value and the current output current value exceeds the set threshold;
[0042] S401: If it is determined that the above difference or ratio exceeds a set threshold, the output current is controlled to delay the increase of the output current from the current output current value to the desired output current value, such that during the process of the output current increasing from the current output current value to the desired output current value or before the output current increases from the current output current value, the states of one or more actuators required to obtain the desired output current value are satisfied; and
[0043] S501: If it is determined that the above difference or ratio does not exceed the set threshold, the output current is controlled to change directly from the current output current value to the desired output current value.
[0044] Figure 1 This is a block diagram illustrating the principle of a method for controlling the output current of a fuel cell stack according to the present invention. Figure 1 In this context, I_actual represents the current output current value of the fuel cell stack to be obtained in step S101, while I_desired represents the desired output current value of the fuel cell stack to be obtained in step S101.
[0045] exist Figure 1 In the diagram, box 100 represents the actuator control module, which is configured to receive the desired output current value I_desired and perform the above-described step S201: controlling one or more actuators used to adjust the reaction conditions at the fuel cell stack so that the one or more actuators reach the state required to achieve the desired output current value. Specific details about the actuator control module 100 will be provided later. Figure 2 describe.
[0046] exist Figure 1 In the diagram, box 200 represents the judgment module, which is configured to perform the above step S301: determine whether the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold.
[0047] The threshold set above can be a threshold for a difference or ratio. Specifically, it can be the absolute value (e.g., in A) of the difference between the desired output current value I_desired and the current output current value I_actual, or the ratio or reciprocal of the absolute value of this difference to the current output current value I_actual, or the ratio or reciprocal of the desired output current value I_desired to the current output current value I_actual. Furthermore, this threshold can be adjusted according to requirements. For example, if it is desirable to minimize the "delay" in the state changes of one or more actuators relative to the desired output current change, which could negatively impact the lifespan of the fuel cell stack, the threshold can be set to a smaller value. By executing this judgment step through the judgment module 100, subsequent steps for controlling the output current are only executed when the difference between the desired output current value I_desired and the current output current value I_actual is significant. This is because a significant difference between the desired output current value I_desired and the current output current value I_actual increases the likelihood of encountering a situation where the state of one or more actuators required to obtain the desired output current value cannot be met.
[0048] The above steps S401 and S501 can be performed by Figure 1 The delay module, represented by box 300, and the switching module, represented by box 400, are implemented in the diagram. The delay module 300 is configured to receive the current output current value I_actual and the desired output current value I_desired, and control the output current to delay the increase of the output current from the current output current value I_actual to the desired output current value I_desired.
[0049] Specifically, delaying the increase of the output current from the current output current value I_actual to the desired output current value I_desired may include controlling the output current to increase from the current output current value I_actual to the desired output current value I_desired after a set time period elapsed from when the increased output current supply requested from the stack is detected.
[0050] Alternatively, delaying the increase of the output current from the current output current value I_actual to the desired output current value I_desired may include controlling the output current to gradually increase from the current output current value I_actual to the desired output current value I_desired. This gradual increase of the output current may include controlling the output current to increase from the current output current value I_actual to the desired output current value I_desired in a controlled manner, for example, following a non-linear pattern. For example, the output current may be controlled to increase from the current output current value I_actual in two or more linear segments until the desired output current value I_desired is reached, or the output current may be controlled to increase from the current output current value I_actual in an exponential manner until the desired output current value I_desired is reached, and so on.
[0051] In other words, when an increased output current supply is requested from the fuel cell stack and it is determined that the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold, instead of controlling the output current to directly change from the current output current value I_actual to the desired output current value as in the prior art, the change in output current is appropriately delayed. The purpose is to counteract the "delay" phenomenon of the change in the state of one or more actuators relative to the change in output current, so that the states of one or more actuators required to obtain the desired output current value are met during the process of the output current increasing from the current output current value I_actual to the desired output current value I_desired, or before the output current increases from the current output current value I_actual.
[0052] The switching module 400 is configured to communicate with the judgment module 200 and the delay module 300 and receive the desired output current value I_desired and the output results of the judgment module 200 and the delay module 300. Specifically, the switching module 400 is configured to set the output current based on the output result received from the delay module 300 if the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold. That is, this corresponds to step S401.
[0053] On the other hand, the switching module 400 is also configured to, if the output result received from the judgment module 200 indicates that the difference or ratio between the desired output current value and the current output current value does not exceed a set threshold, control the output current to directly change from the current output current value I_actual to the desired output current value I_desired, that is, to directly assign the desired output current value I_desired to the set value I_set of the output current. In other words, this corresponds to step S501.
[0054] In summary, by utilizing the method for controlling the output current of a fuel cell stack according to the present invention, when it is determined that the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold, the increase of the output current from the current output current value I_actual to the desired output current value I_desired is delayed. This avoids the phenomenon of "delay" in the state change of one or more actuators relative to the change in output current in the prior art, thereby eliminating the potential negative impact of this "delay" phenomenon on the lifespan of the stack, especially the lifespan of the battery cells at the bottom of the stack.
[0055] Figure 2 This is a schematic diagram illustrating the actuators used to regulate the reaction conditions at the fuel cell stack. The diagram shows: a fuel cell stack 10 including an anode 11 and a cathode 12; a hydrogen supply unit 20 supplying hydrogen to be reacted to the anode 11 of the fuel cell stack 10; an air compressor 30 supplying oxygen (air) to be reacted to the cathode 12 of the fuel cell stack 10; a water separator 40 for separating water from the reaction effluent from the anode 11 of the fuel cell stack; a drain and exhaust valve 50 for discharging water and gas from the water separator 40; and a hydrogen recirculation pump 60 for collecting hydrogen from the reaction effluent from the anode 11 of the fuel cell stack and recirculating the hydrogen downstream of the hydrogen supply unit 20.
[0056] In other words, one or more actuators mentioned in this article include: a hydrogen supply unit 20, an air compressor 30, a water separator 40, a drain and vent valve 50, and a hydrogen recirculation pump 60. The hydrogen recirculation pump 60 is an optional actuator. Furthermore, in conjunction with the preceding... Figure 1 The actuator control module 400 is configured to control these actuators to bring each actuator to the state required to achieve the desired output current value I_desired. Specifically, the actuator control module 400 is configured to control any one of the following or any combination thereof:
[0057] The hydrogen supply rate and pressure of the hydrogen supply unit 20;
[0058] The air supply rate and pressure of air compressor 30;
[0059] The rate at which water separator 40 separates water from the reaction effluent of the anode 11 of the fuel cell stack;
[0060] The discharge rate of water and gas from the water separator 40 is specified by the drain and vent valve 50; and
[0061] The hydrogen recirculation pump 60 collects hydrogen from the reaction effluent of the anode 11 of the fuel cell stack and recirculates the hydrogen downstream of the hydrogen supply unit 20 at a rate that allows it to be recycled.
[0062] It should be noted that, depending on the current output current value I_actual and the desired output current value I_desired, the current state of one or more actuators, and the desired state of one or more actuators corresponding to the desired output current value I_desired, the state of the actuators that need to be regulated can be controlled by the actuator control module 400. For example, it is possible to control only the hydrogen supply unit 20 to increase its hydrogen supply rate and pressure, to control only the hydrogen recirculation pump 60 to increase the rate at which hydrogen is collected from the reaction effluent of the anode 11 of the fuel cell stack and recirculated to the downstream of the hydrogen supply unit 20, or a combination of both, and so on.
[0063] The present invention also proposes a system for controlling the output current of a fuel cell stack, the system being configured to acquire the current output current value and the desired output current value of the stack when a request for an increased output current supply from the stack is detected, and the system comprising:
[0064] The actuator control module 100 is configured to receive the desired output current value I_desired and control one or more actuators for adjusting the reaction conditions at the fuel cell stack so that the one or more actuators reach the state required to achieve the desired output current value.
[0065] The judgment module 200 is configured to receive the current output current value I_actual and the desired output current value I_desired, and determine whether the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold.
[0066] Delay module 300 is configured to receive the current output current value I_actual and the desired output current value I_desired, and control the output current to delay the increase of the output current from the current output current value I_actual to the desired output current value I_desired; and
[0067] The switching module 400 is configured to receive the desired output current value I_desired and the output results of the judgment module 200 and the delay module 300, and is further configured to:
[0068] If the output from the judgment module 200 indicates that the difference or ratio between the desired output current value I_desired and the current output current value I_actual exceeds a set threshold, then the output current is set based on the output from the delay module 300; and
[0069] If the output received from the judgment module 200 indicates that the difference or ratio between the desired output current value I_desired and the current output current value I_actual does not exceed the set threshold, then the output current is controlled to directly change from the current output current value I_actual to the desired output current value I_desired.
[0070] In other words, the system according to the invention is generally configured to implement the method according to the invention. In the system according to the invention, the functions of the actuator control module 100, the judgment module 200, the delay module 300, and the switching module 400 can all be programmed. Therefore, the implementation of the system according to the invention does not increase the hardware cost of the fuel cell stack or occupy any physical space. Furthermore, it avoids the phenomenon of "delay" between the change of the state of each actuator and the change of the output current in the prior art, thereby eliminating the potential negative impact of this "delay" on the lifespan of the stack, especially the lifespan of the battery cells at the bottom of the stack.
[0071] The present invention also proposes a computer program product comprising computer instructions that, when executed by a processor, implement the method according to the present invention.
[0072] The present invention also proposes a machine-readable storage medium storing computer instructions that, when executed by a processor, implement the method according to the present invention.
[0073] The foregoing description, with reference to the accompanying drawings, details feasible but non-limiting embodiments of the method and system for controlling the output current of a fuel cell stack according to the present invention. Modifications and additions to the technology and structure, as well as recombinations of features in the various embodiments, will be readily apparent to those skilled in the art without departing from the scope and spirit of this disclosure as set forth in the following claims. Therefore, such modifications and additions conceivable under the teachings of this invention should be considered part of this disclosure. The scope of this disclosure is defined by the following appended claims and includes equivalent technologies known at the filing date of this disclosure and equivalent technologies not yet foreseen.
Claims
1. Methods for controlling the output current of a fuel cell stack, including: When a request for increased output current supply is detected from the fuel cell stack, the current output current value and the desired output current value of the fuel cell stack are obtained; Control one or more actuators used to regulate the reaction conditions at the fuel cell stack so that the one or more actuators reach the state required to achieve the desired output current value; Determine whether the difference or ratio between the expected output current value and the current output current value exceeds a set threshold; If it is determined that the difference or ratio exceeds the set threshold, the output current is controlled to delay the increase of the output current from the current output current value to the desired output current value, so that the state of one or more actuators required to obtain the desired output current value is satisfied during the process of the output current increasing from the current output current value to the desired output current value or before the output current increases from the current output current value. as well as If it is determined that the difference or ratio does not exceed the set threshold, the output current is controlled to directly change from the current output current value to the desired output current value.
2. The method according to claim 1, wherein the set threshold is the absolute value of the difference between the desired output current value and the current output current value, or the ratio or reciprocal of the absolute value of the difference to the current output current value, or the ratio or reciprocal of the desired output current value to the current output current value.
3. The method of claim 1, wherein controlling the plurality of actuators comprises controlling any one or any combination of the following: The hydrogen supply rate and pressure of the hydrogen supply unit (20) of the fuel cell; The air supply rate and pressure of the air compressor (30) of the fuel cell; The rate at which the water separator (40) of the fuel cell separates water from the reaction effluent of the anode of the fuel cell stack; The drain and vent valve (50) of the fuel cell discharges water and gas from the water separator (40) at a rate that allows for the discharge of water and gas. The hydrogen recirculation pump (60) of the fuel cell collects hydrogen from the reaction effluent of the anode of the stack and recirculates the hydrogen to the downstream of the hydrogen supply unit (20) at a rate.
4. The method according to any one of claims 1 to 3, wherein delaying the increase of the output current from the current output current value to the desired output current value comprises: After a set time period elapses following the detection of a request for increased output current from the fuel cell stack, the output current is controlled to increase from the current output current value to the desired output current value.
5. The method according to any one of claims 1 to 3, wherein delaying the increase of the output current from the current output current value to the desired output current value comprises: The output current is controlled to gradually increase from the current output current value to the desired output current value.
6. The method of claim 5, wherein controlling the output current to gradually increase from the current output current value to the desired output current value comprises: The output current is controlled to increase linearly from the current output current value in two or more segments until the desired output current value is reached.
7. The method of claim 5, wherein controlling the output current to gradually increase from the current output current value to the desired output current value comprises: The output current is controlled to increase exponentially from the current output current value until the desired output current value is reached.
8. A system for controlling the output current of a fuel cell stack, the system being configured to: upon detecting a request for an increased output current supply from the stack, acquire a current output current value and a desired output current value of the stack, and the system comprising: An actuator control module (100) is configured to receive the desired output current value and control one or more actuators for adjusting the reaction conditions at the fuel cell stack so that the one or more actuators reach the state required to achieve the desired output current value. The judgment module (200) is configured to receive the current output current value and the expected output current value, and to determine whether the difference or ratio between the expected output current value and the current output current value exceeds a set threshold. A delay module (300) is configured to receive the current output current value and the desired output current value, and control the output current to delay the increase of the output current from the current output current value to the desired output current value; as well as A switching module (400) is configured to receive the desired output current value and the output results of the judgment module (200) and the delay module (300), and is further configured to: If the output result received from the judgment module (200) indicates that the difference or ratio between the expected output current value and the current output current value exceeds the set threshold, then the output current is set based on the output result received from the delay module (300). as well as If the output result received from the judgment module (200) is that the difference or ratio between the expected output current value and the current output current value does not exceed the set threshold, then the output current is controlled to directly change from the current output current value to the expected output current value.
9. The system of claim 8, wherein the one or more actuators comprise one or more of the following: A hydrogen supply unit (20) supplies hydrogen to be reacted to the anode of the fuel cell stack; An air compressor (30) supplies oxygen to be reacted to the cathode of the fuel cell stack; A water separator (40) for separating water from the reaction effluent of the anode of the fuel cell stack; A drain and vent valve (50) for discharging water and gas from the water separator (40); and A hydrogen recirculation pump (60) for collecting hydrogen from the reaction effluent of the anode of the fuel cell stack and recirculating the hydrogen to the downstream of the hydrogen supply unit (20).
10. A computer program product comprising computer instructions that, when executed by a processor, implement the method according to any one of claims 1 to 7.