A method and system for voltage control of a fuel cell under grid disturbance

Abstract

The application provides a fuel cell voltage control method and system under power grid disturbance, and belongs to the technical field of fuel cell voltage control; whether there is power grid disturbance under low-voltage ride-through is judged according to the power grid operation state detected by a power grid disturbance detection component; when disturbance exists, a differential tracker is used to track and filter the voltage under the present state, and an uncertainty factor of the fuel cell is observed based on a disturbance observer; subsequently, the results obtained by the differential tracker and the disturbance observer are input into a nonlinear error feedback compensator to generate a reaction gas compensation amount, and the reaction gas excess coefficient and the reaction gas circulation rate are adjusted to make the voltage recover stable, and voltage control is realized. The application can realize fast and effective control of the fuel cell voltage under power grid disturbance of low-voltage ride-through, thereby prolonging the service life of the fuel cell and maintaining the working environment of the fuel cell to be stable.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell voltage control technology, and particularly relates to a fuel cell voltage control method and system under power grid disturbances. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] As a highly efficient and environmentally friendly energy conversion device, fuel cells are gradually becoming an important development direction in the energy field. Their basic principle is to directly convert the chemical energy in fuel into electrical energy, producing almost no harmful emissions in the process, thus being considered a key component of future energy technology. Currently, fuel cells (such as proton exchange membrane fuel cells, PEMFCs) are most widely used in the transportation sector, especially in the automotive industry, where fuel cell electric vehicles (FCEVs) have received widespread attention for their zero emissions and high energy conversion efficiency. In addition, fuel cells also play an important role in high-reliability power supply applications such as data centers, hospitals, and communication base stations.

[0004] However, despite the numerous advantages of fuel cell technology, when connected to the grid, fuel cells inevitably experience grid disturbances due to low-voltage ride-through, during which they cannot function properly. To address this, engineers in the field have implemented various control methods to improve fuel cells, but these methods still present some technical challenges, such as:

[0005] (1) When a low-voltage ride occurs, the existing fuel cell control methods mostly choose to use an additional backup component (such as an uninterruptible power supply) for power supply. However, this requires adding other power supply components on top of the existing fuel cell. In other words, relying solely on a single fuel cell cannot effectively control the voltage value and maintain its internal stability, making it difficult to cope with grid disturbances under low-voltage ride on its own; moreover, this will undoubtedly increase construction costs.

[0006] (2) Existing technologies also include methods to increase the voltage of a fuel cell by directly increasing the voltage or the amount of reactant gas. However, the increased voltage and amount of reactant gas are determined empirically, which can easily lead to instability and abnormal temperature inside the cell. Therefore, the voltage is not easily controlled within the optimal range, which can severely affect the lifespan of the fuel cell. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a method and system for controlling fuel cell voltage under grid disturbances, which can achieve accurate and effective control of fuel cell voltage under grid disturbances with low-voltage ride-through, thereby extending the service life of fuel cell and maintaining a stable working environment for fuel cell.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0009] The first aspect of the present invention provides a method for controlling the voltage of a fuel cell under power grid disturbances.

[0010] A method for controlling fuel cell voltage under grid disturbances includes:

[0011] The system uses a grid disturbance detection component to detect the grid operating status in real time and determines whether there is a grid disturbance under low-voltage ride-through based on the grid operating status.

[0012] When grid disturbances occur, a differential tracker is used to track and filter the voltage under the current state, and a disturbance observer is used to observe the uncertainties of the fuel cell. Then, the results obtained from the differential tracker and the disturbance observer are simultaneously input into a nonlinear error feedback compensator to determine the amount of reactant gas to be compensated for when inputting into the fuel cell.

[0013] Adjust the excess coefficient and circulation rate of the reactant gas based on the obtained reactant gas compensation amount to restore voltage stability, thereby achieving voltage control of the fuel cell.

[0014] Furthermore, the determination of whether there is a grid disturbance under low-voltage ride-through based on the grid operation status includes: when the phase-to-phase voltage between any two phases of the three-phase power grid is lower than the preset first phase-to-phase voltage threshold, it is considered that there is a grid disturbance under low-voltage ride-through.

[0015] Furthermore, the differential tracker is represented as:

[0016]

[0017] u r (t+1) and u r (t) represents the pre-tracking voltage of the differential tracker at time t+1 and time t, respectively. and These represent the pre-tracking voltage u. r (t+1) and u r The derivative of (t), T d denoted by , and fhan(t) denotes the steepest synthesis function.

[0018] Furthermore, the uncertainties of the fuel cell are observed based on the disturbance observer, wherein the uncertainties include load current disturbances, ambient temperature disturbances, and changes in reactant gas flow rate in the fuel cell.

[0019] Furthermore, the nonlinear error feedback compensator, based on its built-in nonlinear feedback function, generates a compensation amount of the reaction gas input to the fuel cell based on proportional-derivative control parameters.

[0020] Furthermore, the excess reactant coefficient and the recirculation rate are adjusted based on the obtained reactant gas compensation amount. Specifically, the obtained reactant gas compensation amount and the actual amount of reactant gas fed into the fuel cell in the previous state are used as the total reactant gas input amount and fed into the fuel cell together. By increasing the reactant gas input amount, the excess reactant coefficient and the recirculation rate are improved, thereby increasing the voltage.

[0021] A second aspect of the present invention provides a fuel cell voltage control system under power grid disturbances.

[0022] A fuel cell voltage control system under grid disturbance includes: a fuel cell stack, a grid disturbance detection component, a first control component, and a second control component; wherein the first control component consists of a differential tracker, a disturbance observer, and a nonlinear error feedback compensator;

[0023] The power grid disturbance detection component is configured to: detect the power grid operating status in real time, and determine whether there is a power grid disturbance under low voltage ride-through based on the power grid operating status;

[0024] The first control component is configured to: when there is a grid disturbance, use a differential tracker to track and filter the voltage under the current state, and observe the uncertainty factors of the fuel cell based on the disturbance observer; then, input the results obtained from the differential tracker and the disturbance observer into a nonlinear error feedback compensator to determine the amount of reactant gas compensation to be input into the fuel cell.

[0025] The second control component is configured to adjust the excess coefficient and circulation rate of the reactant gas according to the obtained reactant gas compensation amount, so as to restore the voltage to stability and thereby achieve voltage control of the fuel cell.

[0026] Furthermore, the second control component includes an air compressor and a circulation pump; wherein the air compressor is used to adjust the excess coefficient of the reactant gas by adjusting the input amount of the reactant gas, and the circulation pump is used to adjust the circulation rate of the reactant gas.

[0027] Furthermore, the first port of the air compressor and the second port of the circulating pump are respectively connected to the cathode inlet and cathode outlet of the fuel cell stack. At the same time, the second port of the air compressor and the first port of the circulating pump are connected together. The third port of the air compressor and the third port of the circulating pump are both connected to the second control component. The other end of the second control component is connected to the power grid disturbance detection component, and the other end of the power grid disturbance detection component is connected to the power grid.

[0028] Furthermore, the power grid disturbance detection component includes a first acquisition device, a second acquisition device, and a third acquisition device, which are used to directly acquire the voltage signal of the connected power grid in order to detect the power grid operating status in real time.

[0029] The above one or more technical solutions have the following beneficial effects:

[0030] (1) When there is a grid disturbance during low-voltage ride-through, this invention uses a differential tracker to first track and filter the voltage, and observes the uncertainties of the fuel cell based on a disturbance observer. Subsequently, the results obtained from the differential tracker and the disturbance observer are simultaneously input into a nonlinear error feedback compensator to determine the amount of reactant gas to be compensated for the fuel cell. By increasing the amount of reactant gas compensation, the voltage is indirectly increased. The entire process does not require any external backup components to replace the fuel cell for power supply, and the internal voltage can be quickly restored to stability. Moreover, it can reduce construction costs.

[0031] (2) This invention, through the cooperation of a differential tracker, a disturbance observer, and a nonlinear error feedback compensator, can accurately determine the amount of additional reactant gas required for compensation. Compared to existing technologies, this adjustment method can maintain the internal operating environment and temperature of the fuel cell at normal levels. Therefore, based on the voltage control method provided by this invention, the voltage can be better controlled within the optimal range, thereby enabling accurate and effective control of the fuel cell voltage under grid disturbances such as low-voltage ride-through, thus extending the service life of the fuel cell and maintaining a stable operating environment.

[0032] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0034] Figure 1 This is a flowchart of a fuel cell voltage control method under power grid disturbance according to Embodiment 1 of the present invention.

[0035] Figure 2 This is a schematic diagram of the structural composition of a fuel cell voltage control system under power grid disturbance in Embodiment 2 of the present invention. Detailed Implementation

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0038] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0039] Example 1

[0040] This embodiment discloses a method for controlling fuel cell voltage under power grid disturbances.

[0041] like Figure 1 As shown, a fuel cell voltage control method under grid disturbance includes:

[0042] Step S1: Detect the grid operating status in real time based on the grid disturbance detection component, and determine whether there is a grid disturbance under low-voltage ride-through based on the grid operating status;

[0043] Step S2: When there is a grid disturbance, a differential tracker is used to track and filter the voltage under the current state, and the uncertainty factors of the fuel cell are observed based on the disturbance observer; then, the results obtained from the differential tracker and the disturbance observer are simultaneously input into the nonlinear error feedback compensator to determine the amount of reactant gas compensation used to input the fuel cell.

[0044] Step S3: Adjust the excess coefficient and circulation rate of the reactant gas according to the obtained reactant gas compensation amount to restore voltage stability, thereby achieving voltage control of the fuel cell.

[0045] Based on the above process, this invention can achieve accurate and effective control of fuel cell voltage under grid disturbances such as low-voltage ride-through, thereby extending the service life of the fuel cell and maintaining a stable operating environment. To facilitate understanding of the technical solution of this invention, the specific implementation steps are further explained and described below.

[0046] Step S1: Real-time detection of the power grid operating status based on the power grid disturbance detection component, and determination of whether there is a power grid disturbance under low-voltage ride-through based on the power grid operating status.

[0047] Step S1-1: Real-time detection of power grid operating status based on power grid disturbance detection component.

[0048] The power grid disturbance detection component includes a first acquisition device, a second acquisition device, and a third acquisition device. These three acquisition devices are used to directly acquire voltage signals from the connected power grid to facilitate real-time monitoring of the grid's operating status. Specifically, the first, second, and third acquisition devices acquire the three-phase voltages of the power grid through direct connection to the grid.

[0049] In this embodiment, the first, second, and third data acquisition devices are all high-precision voltage sensors. The first data acquisition device is connected to phase A of the power grid and measures the voltage of phase A using a high-precision voltage sensor; the second data acquisition device is connected to phase B of the power grid and also measures the voltage of phase B using a high-precision voltage sensor; the third data acquisition device is connected to phase C of the power grid and measures the voltage of phase C. Before the first, second, and third data acquisition devices are put into use, their parameters need to be configured, including setting the sampling frequency and calibrating the voltage sensors. Parameter configuration can be performed through physical buttons on the data acquisition devices, a touchscreen interface, or a remote communication interface.

[0050] Step S1-2: Determine whether there is a power grid disturbance under low-voltage ride-through based on the power grid operating status.

[0051] The power grid disturbance detection component also includes a judgment device, which can be a small PLC programmable logic controller. This device connects to the data acquisition devices via a communication interface to receive voltage data collected by the first, second, and third data acquisition devices and determine the power grid's operating status. It should be noted that the judgment device can also be replaced by other equipment as needed, as long as it can make a ratio judgment based on the collected voltages.

[0052] A first phase-to-phase voltage threshold and a second phase-to-phase voltage threshold are preset, wherein the first phase-to-phase voltage threshold is less than the second phase-to-phase voltage threshold. A judgment device compares the received three-phase voltage values ​​of the power grid with the first and second phase-to-phase voltage thresholds. When the phase-to-phase voltage between any two phases of the received three-phase voltage is less than the preset first phase-to-phase voltage threshold, it is considered that the voltage drop in the power grid is too large, i.e., a low-voltage ride-through has occurred. At this time, the judgment device sends a voltage control start signal to remind the first control component to start voltage control. When the phase-to-phase voltage between any two phases of the received three-phase voltage is greater than the preset second phase-to-phase voltage threshold, it indicates that the voltage has been regulated to the normal range by the voltage control method of this invention. At this time, the judgment device sends a voltage control end signal to remind the first control component to stop voltage control. Further, in actual implementation, code '0' can be used as the voltage control start signal and code '1' as the voltage control end signal.

[0053] Step S2: When grid disturbances occur, a differential tracker is used to track and filter the voltage under the current state, and an observation of uncertainties in the fuel cell is performed based on a disturbance observer. Subsequently, the results obtained from the differential tracker and the disturbance observer are simultaneously input into a nonlinear error feedback compensator to determine the amount of reactant gas to be compensated for inputting into the fuel cell. In this embodiment, hydrogen is selected as the reactant gas, but this is not the only option; the specific reactant gas can be selected according to the actual situation.

[0054] When the first control component receives a voltage control start signal, it begins to execute voltage control. Specifically, the first control component determines the amount of reactant gas compensation to be input into the fuel cell by tracking the voltage state of the fuel cell, and prepares for subsequent voltage control by adding an appropriate amount of reactant gas. The first control component includes a differential tracker, a disturbance observer, and a nonlinear error feedback compensator. The determination of the reactant gas compensation amount based on the first control component can be achieved through the following steps.

[0055] Step S2-1: When there is a power grid disturbance, a differential tracker is used to track and filter the voltage under the current condition.

[0056] The main function of a differential tracker is to quickly and smoothly lock onto the control signal of the pre-tracking voltage and calculate its differential signal; simultaneously, it filters the locked pre-tracking voltage control signal to reduce noise interference. Specifically, a differential tracker is represented as follows:

[0057]

[0058] u r (t+1) and u r(t) represents the pre-tracking voltage of the differential tracker at time t+1 and time t, respectively. and These represent the pre-tracking voltage u. r (t+1) and u r The derivative of (t), T d denoted by , and fhan(t) denotes the steepest synthesis function.

[0059] fhan(t), as the steepest synthesis function, is mathematically represented as:

[0060]

[0061] Among them, v s The speed factor used to adjust the tracking speed is represented by d, the linear interval length is represented by h, the sampling step size is represented by c, the number of linear segments is represented by c0, the linear segment control coefficient is represented by d0, the total step size under the linear interval length is represented by u0, and the actual output voltage of the fuel cell is represented by u0.

[0062] Step S2-2: Observe the uncertainties of the fuel cell based on the disturbance observer.

[0063] After tracking and filtering the voltage under the current state, the uncertainties of the fuel cell are observed based on the disturbance observer. These uncertainties include load current disturbances, ambient temperature disturbances, and changes in reactant gas flow rates. These uncertainties are collectively estimated as the total disturbance factor in real time. Specifically, the main algorithm of the disturbance observer can be expressed as follows:

[0064]

[0065] Where e represents the tracking error, g1(t), g2(t), and g3(t) represent the estimated values ​​of load current disturbance, ambient temperature disturbance, and reactant gas flow rate at time t, respectively; g1(t+1), g2(t+1), and g3(t+1) represent the estimated values ​​of load current disturbance, ambient temperature disturbance, and reactant gas flow rate at time t+1, respectively; β1 represents the proportional coefficient, β2 represents the differential coefficient, and β3 represents the gain coefficient; nfal() represents the nonlinear function, δ represents the length of the linear interval, b0 represents the estimated value of the input gain b, y(t) represents the control quantity at time t, y0(t) represents the expected control quantity at time t, and c1 and c2 represent the nonlinear segment control coefficients.

[0066] Furthermore, when the estimated value of the reactant gas flow rate differs sufficiently from the total disturbance error, the transfer function can be designed as follows:

[0067]

[0068] in, Let g represent the transfer function value, G represent the total disturbance error, g3 represent the estimated reactant gas flow rate, and y0 represent the reactant gas compensation amount used as input to the fuel cell. Based on this, only a nonlinear error feedback compensator is needed to provide feedback on the reactant gas compensation amount.

[0069] Step S2-3: Simultaneously input the results obtained from the differential tracker and the disturbance observer into the nonlinear error feedback compensator to determine the amount of reaction gas compensation used to input the fuel cell.

[0070] The nonlinear error feedback compensator, based on its built-in nonlinear feedback function, generates the compensation amount of the reactant gas input to the fuel cell based on proportional-derivative control parameters. Specifically, the nonlinear function nfal(.) can be expressed as:

[0071]

[0072] Among them, c f Let represent the control coefficient for the nonlinear segment, and δ represent the length of the linear interval. Further, the feedback control algorithm based on proportional-derivative control parameters is expressed as:

[0073] y0=β1*nfal(e1,c1,δ)+β2*nfal(e2,c2,δ);

[0074] Where y0 represents the amount of reaction gas compensation used to input the fuel cell, and e1 and e2 represent the tracking errors for load current disturbance and ambient temperature disturbance, respectively.

[0075] Step S3: Adjust the excess coefficient and circulation rate of the reactant gas according to the obtained reactant gas compensation amount to restore voltage stability, thereby achieving voltage control of the fuel cell.

[0076] The excess reactant coefficient and recirculation rate are adjusted based on the obtained reactant gas compensation amount. Specifically, the obtained reactant gas compensation amount and the actual amount of reactant gas fed into the fuel cell in the previous state are used as the total reactant gas input, which is then fed into the fuel cell. Increasing the reactant gas input increases the excess reactant coefficient and recirculation rate, thereby increasing the voltage. The excess reactant coefficient represents the ratio of the amount of reactant gas entering the fuel cell through the cathode inlet to the amount of reactant gas actually participating in the reaction; the reactant gas amount represents the amount of reactant gas entering the fuel cell through the cathode inlet; and the recirculation rate represents the percentage of reactant gas discharged from the cathode outlet that re-enters the fuel cell through the cathode inlet, relative to the total amount of reactant gas flowing into the fuel cell.

[0077] When a low-pressure ride-through occurs, the first control component generates the required amount of reactant gas compensation. At this time, the second control component begins to increase the input of reactant gas according to the required compensation amount. Specifically, the second control component includes an air compressor and a circulation pump. The air compressor, based on the required compensation amount, combines the obtained reactant gas compensation amount with the actual amount of reactant gas introduced into the fuel cell in the previous state as the total reactant gas input, which is then fed into the fuel cell. This increases the gas excess coefficient, and as the gas excess coefficient increases, the operating voltage of the fuel cell stack rises. Simultaneously, the gas recirculation rate is reduced based on the increased gas excess coefficient to keep the amount of reactant gas passing through the fuel cell stack within a reasonable range.

[0078] Furthermore, adjusting the gas recirculation rate based on the gas excess coefficient can be achieved using the following formula:

[0079]

[0080] Q represents the recirculation rate of the reactant gas, A represents the initial value of the recirculation rate of the reactant gas, and B represents the excess coefficient of the reactant gas.

[0081] Therefore, when a low-voltage ride-through occurs, this invention can control the fuel cell operating voltage within the normal range, and when the low-voltage ride-through ends, voltage control can be terminated. Thus, this invention can achieve accurate and effective control of the fuel cell voltage under grid disturbances such as low-voltage ride-throughs, thereby extending the fuel cell's lifespan and maintaining a stable operating environment.

[0082] Example 2

[0083] This embodiment discloses a fuel cell voltage control system under power grid disturbances.

[0084] like Figure 2 As shown, a fuel cell voltage control system under grid disturbance includes: a fuel cell stack, a grid disturbance detection component, a first control component, and a second control component; wherein, the first control component consists of a differential tracker, a disturbance observer, and a nonlinear error feedback compensator;

[0085] The power grid disturbance detection component is configured to: detect the power grid operating status in real time, and determine whether there is a power grid disturbance under low voltage ride-through based on the power grid operating status;

[0086] The first control component is configured to: when there is a grid disturbance, use a differential tracker to track and filter the voltage under the current state, and observe the uncertainty factors of the fuel cell based on the disturbance observer; then, input the results obtained from the differential tracker and the disturbance observer into a nonlinear error feedback compensator to determine the amount of reactant gas compensation to be input into the fuel cell.

[0087] The second control component is configured to adjust the excess coefficient and circulation rate of the reactant gas according to the obtained reactant gas compensation amount, so as to restore the voltage to stability and thereby achieve voltage control of the fuel cell.

[0088] Furthermore, the second control component includes an air compressor and a circulation pump; wherein the air compressor is used to adjust the excess coefficient of the reactant gas by adjusting the input amount of the reactant gas, and the circulation pump is used to adjust the circulation rate of the reactant gas.

[0089] Furthermore, the first port of the air compressor and the second port of the circulating pump are respectively connected to the cathode inlet and cathode outlet of the fuel cell stack. At the same time, the second port of the air compressor and the first port of the circulating pump are connected together. The third port of the air compressor and the third port of the circulating pump are both connected to the second control component. The other end of the second control component is connected to the power grid disturbance detection component, and the other end of the power grid disturbance detection component is connected to the power grid.

[0090] Furthermore, the power grid disturbance detection component includes a first acquisition device, a second acquisition device, and a third acquisition device, which are used to directly acquire the voltage signal of the connected power grid in order to detect the power grid operating status in real time.

[0091] The steps and methods involved in the apparatus of Embodiment 2 above correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1.

[0092] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0093] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for controlling fuel cell voltage under grid disturbances, characterized in that, include: The system uses a grid disturbance detection component to detect the grid operating status in real time and determines whether there is a grid disturbance under low-voltage ride-through based on the grid operating status. Determining whether there is a grid disturbance under low-voltage ride-through based on the grid operation status includes: when the phase-to-phase voltage between any two phases of the three-phase power grid is lower than the preset first phase-to-phase voltage threshold, it is considered that there is a grid disturbance under low-voltage ride-through. When grid disturbances occur, a differential tracker is used to track and filter the voltage under the current state, and a disturbance observer is used to observe the uncertainties of the fuel cell. These uncertainties include load current disturbances, ambient temperature disturbances, and changes in reactant gas flow rates. Subsequently, the results from both the differential tracker and the disturbance observer are simultaneously input into a nonlinear error feedback compensator to determine the amount of reactant gas compensation used to input into the fuel cell. The main algorithm of the disturbance observer is as follows: ； in, Indicates tracking error. , and These represent the effects of load current disturbance, ambient temperature disturbance, and reactant gas flow rate on time. The estimated value at that time, , and These represent the effects of load current disturbance, ambient temperature disturbance, and reactant gas flow rate on time. The estimated value at that time; This represents the proportionality coefficient. Represents the differential coefficient. Indicates the gain coefficient; Indicates the length of the linear interval. Indicates the input gain The estimated value, Indicates time Control quantity at time, Indicates time The expected control amount at that time and Indicates the control coefficient for the nonlinear segment; It is a nonlinear function, expressed as: in, Represents the control coefficient for the nonlinear segment. Indicates the length of the linear interval; in the nonlinear function c Indicates the control coefficient for the nonlinear segment; Adjust the excess coefficient and circulation rate of the reactant gas based on the obtained reactant gas compensation amount to restore voltage stability, thereby achieving voltage control of the fuel cell.

2. The fuel cell voltage control method under grid disturbance as described in claim 1, characterized in that, The differential tracker is represented as follows: ； and These represent the time of the differential tracker. and time Pre-tracking voltage at time and These represent the pre-tracking voltages. and The derivative of Indicates the sampling period. Represents the steepest synthesis function; As the steepest synthesis function, it is mathematically represented as: ； in, This represents the speed factor used to adjust the tracking speed. Indicates the length of the linear interval. Indicates the sampling step size, in the fastest synthesis function Indicates the number of segments in a linear segment. This represents the control coefficient for the linear segment. This represents the total step size within the length of the bus linear interval. This indicates the actual output voltage of the fuel cell.

3. The fuel cell voltage control method under grid disturbance as described in claim 1, characterized in that, The nonlinear error feedback compensator generates a compensation amount of reactant gas for input to the fuel cell based on proportional-derivative control parameters, using a built-in nonlinear feedback function.

4. The fuel cell voltage control method under grid disturbance as described in claim 3, characterized in that, The feedback control algorithm based on the proportional-derivative control parameters is expressed as follows: ； in, This indicates the amount of reactant gas used to compensate for the input to the fuel cell. and These represent the tracking errors for load current disturbances and ambient temperature disturbances, respectively.

5. The fuel cell voltage control method under grid disturbance as described in claim 1, characterized in that, The excess reactant coefficient and the recirculation rate are adjusted based on the obtained reactant gas compensation amount. Specifically, the obtained reactant gas compensation amount and the actual amount of reactant gas fed into the fuel cell in the previous state are used as the total reactant gas input amount and fed into the fuel cell together. By increasing the reactant gas input amount, the excess reactant coefficient and the recirculation rate are improved, thereby increasing the voltage.

6. A fuel cell voltage control system under grid disturbance, employing the fuel cell voltage control method under grid disturbance as described in any one of claims 1-5, characterized in that, include: The system comprises an electric stack, a power grid disturbance detection component, a first control component, and a second control component; wherein the first control component consists of a differential tracker, a disturbance observer, and a nonlinear error feedback compensator. The power grid disturbance detection component is configured to: detect the power grid operating status in real time, and determine whether there is a power grid disturbance under low voltage ride-through based on the power grid operating status; The first control component is configured to: when there is a grid disturbance, use a differential tracker to track and filter the voltage under the current state, and observe the uncertainties of the fuel cell based on the disturbance observer; Subsequently, the results obtained from the differential tracker and the disturbance observer are simultaneously input into the nonlinear error feedback compensator to determine the amount of reactant gas compensation used to input the fuel cell. The second control component is configured to adjust the excess coefficient and circulation rate of the reactant gas according to the obtained reactant gas compensation amount, so as to restore the voltage to stability and thereby achieve voltage control of the fuel cell.

7. A fuel cell voltage control system under grid disturbance as described in claim 6, characterized in that, include: The second control component includes an air compressor and a circulation pump; wherein the air compressor is used to adjust the excess coefficient of the reactant gas by adjusting the input amount of the reactant gas, and the circulation pump is used to adjust the circulation rate of the reactant gas.

8. A fuel cell voltage control system under grid disturbance as described in claim 7, characterized in that, The first port of the air compressor and the second port of the circulating pump are respectively connected to the cathode inlet and cathode outlet of the fuel cell stack. At the same time, the second port of the air compressor and the first port of the circulating pump are connected together. The third port of the air compressor and the third port of the circulating pump are both connected to the second control component. The other end of the second control component is connected to the power grid disturbance detection component, and the other end of the power grid disturbance detection component is connected to the power grid.

9. A fuel cell voltage control system under grid disturbance as described in claim 8, characterized in that, The power grid disturbance detection component includes a first acquisition device, a second acquisition device, and a third acquisition device, which are used to directly acquire the voltage signal of the connected power grid in order to detect the power grid operating status in real time.

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