A fuel cell inverter control method and apparatus

Abstract

The application provides a fuel cell converter control method and device, which is applied to a converter, and given preset parameter values in a control instruction are divided into target preset parameter values of N control periods, so that input preset parameter values of the converter, such as input current, linearly reach given values, and a multi-step prediction method is adopted to calculate predicted preset parameter values corresponding to different converter switch states in each control period according to an IV curve of the fuel cell, a value function is constructed according to the target preset parameter values and the predicted preset parameter values, optimal solutions of the value function in each control period are determined and executed, the dynamic response capability of the converter is improved, sudden changes of input preset parameter values of the converter are avoided, that is, sudden changes of output preset parameter values of the fuel cell are avoided, for example, sudden changes of input currents of the converter are avoided, that is, sudden changes of output currents of the fuel cell are avoided, so that damage to the fuel cell is reduced, and the service life of the fuel cell is prolonged.

Description

Technical Field

[0001] This invention relates to the field of automation control technology, and more specifically, to a fuel cell converter control method and apparatus. Background Technology

[0002] A fuel cell system consists of a fuel cell, a DC-DC converter, and a load. Please refer to [link / reference]. Figure 1 Fuel cells convert hydrogen energy into electrical energy, which is then fed into a DC-DC power supply. After further DC-DC conversion, the electrical energy is supplied to the load. The output parameters of the fuel cell are the input parameters of the DC-DC power supply. For example, the output current of the fuel cell is the input current of the DC-DC power supply. In addition, the DC-DC power supply in the fuel cell system can also be replaced by a DC-AC power supply.

[0003] In a fuel cell system, the flow and pressure of fuel are adjusted according to changes in the power demand of the load. This adjustment process takes a long time. If a sudden change in load occurs, the fuel cell cannot keep up with the rate of load change, which will lead to a lack of gas in the fuel cell stack and severely reduce the service life of the fuel cell. Summary of the Invention

[0004] In view of this, the present invention provides a fuel cell converter control method and apparatus to avoid sudden changes in preset input parameter values ​​of the converter, that is, to avoid sudden changes in preset output parameter values ​​of the fuel cell, such as to avoid sudden changes in the input current of the converter, that is, to avoid sudden changes in the output current of the fuel cell, thereby reducing damage to the fuel cell.

[0005] To achieve the above-mentioned objectives, the present invention provides the following specific technical solution:

[0006] A fuel cell converter control method, applied to a converter, the method comprising:

[0007] Upon receiving a control command, the given preset parameter value in the control command is divided into target preset parameter values ​​for N control cycles based on the current input preset parameter value, where N is a positive integer. The rate of change of the target preset parameter value in each control cycle is less than the maximum rate of change of the preset parameter value allowed by the fuel cell.

[0008] A multi-step prediction method is adopted to calculate the predicted preset parameter values ​​corresponding to different converter switching states in each control cycle based on the IV curve of the fuel cell.

[0009] A value function is constructed based on the target preset parameter value and the prediction preset parameter value, and the optimal solution of the value function is determined in each control cycle;

[0010] The converter control operation corresponding to the optimal solution is executed sequentially in each control cycle.

[0011] Optionally, the preset parameter value is either the current value or the power value.

[0012] Optionally, the step of dividing the given preset parameter value in the control command into N control cycles based on the current input preset parameter value includes:

[0013] Calculate the difference between the given preset parameter value and the preset parameter value of the current control cycle, and calculate the ratio of the difference to N, where the preset parameter value of the current control cycle is the current input preset parameter value;

[0014] The sum of the current input preset parameter value and the ratio is determined as the target preset parameter value for the next control cycle.

[0015] Optionally, the multi-step prediction method calculates predicted preset parameter values ​​corresponding to different converter switching states within each control cycle based on the IV curve of the fuel cell, including:

[0016] The control cycle is divided into M sub-cycles, where M is a positive integer;

[0017] Discrete models are constructed based on different converter switching states, and each sub-cycle in the discrete model corresponds to its respective converter switching state.

[0018] A multi-step prediction method is adopted, and the predicted preset parameter values ​​corresponding to each discrete model in each control cycle are calculated offline based on the IV curve of the fuel cell.

[0019] Optionally, the step of constructing discrete models according to different converter switching states includes:

[0020] Based on the converter's topology, determine the different switching states corresponding to the topology and establish the corresponding state equations for each switching state.

[0021] Optionally, a value function is constructed based on the target preset parameter value and the prediction preset parameter value, and the optimal solution of the value function is determined in each control cycle, including:

[0022] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0023] The converter switching state corresponding to the minimum value of the value function is determined as the optimal solution.

[0024] Optionally, a value function is constructed based on the target preset parameter value and the prediction preset parameter value, and the optimal solution of the value function is determined in each control cycle, including:

[0025] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0026] Add constraints to the value function;

[0027] Under the constraints of the stated constraints, the optimal solution of the value function in each of the stated control cycles is determined.

[0028] Optionally, the constraints include at least one of the following:

[0029] The duty cycle corresponding to the switching state of the converter has the smallest fluctuation value in the adjacent control cycle, and the duty cycle ranges from (0,1).

[0030] The target preset parameter value has the smallest fluctuation value in adjacent control cycles, and the target preset parameter value is the target input current;

[0031] The input voltage fluctuation is minimized in adjacent control cycles;

[0032] The input power fluctuation is minimized in adjacent control cycles.

[0033] A fuel cell converter control device, applied to a converter, the device comprising:

[0034] A preset parameter value division unit is provided to divide the given preset parameter value in the control command into target preset parameter values ​​for N control cycles based on the current input preset parameter value when a control command is received. N is a positive integer, and the rate of change of the target preset parameter value in each control cycle is less than the maximum rate of change of the preset parameter value allowed by the fuel cell.

[0035] The preset parameter value prediction unit is used to calculate the predicted preset parameter values ​​corresponding to different converter switching states in each control cycle based on the IV curve of the fuel cell using a multi-step prediction method.

[0036] The value function solving unit is used to construct a value function based on the target preset parameter value and the prediction preset parameter value, and to determine the optimal solution of the value function in each control cycle;

[0037] The converter control unit is used to sequentially execute the converter control operation corresponding to the optimal solution in each control cycle.

[0038] Optionally, the preset parameter value is either the current value or the power value.

[0039] Optionally, the given preset parameter value partitioning unit is specifically used for:

[0040] Calculate the difference between the given preset parameter value and the preset parameter value of the current control cycle, and calculate the ratio of the difference to N, where the preset parameter value of the current control cycle is the current input preset parameter value;

[0041] The sum of the current input preset parameter value and the ratio is determined as the target preset parameter value for the next control cycle.

[0042] Optionally, the preset parameter value prediction unit includes:

[0043] The sub-cycle division sub-unit is used to divide the control cycle into M sub-cycles, where M is a positive integer;

[0044] Discrete model construction sub-units are used to construct discrete models according to different converter switching states, wherein each sub-cycle in the discrete model corresponds to its respective converter switching state.

[0045] The offline calculation subunit is used to calculate the predicted preset parameter values ​​corresponding to each discrete model in each control cycle based on the IV curve of the fuel cell using a multi-step prediction method.

[0046] Optionally, the discrete model construction sub-unit is specifically used to determine the state equations corresponding to different switching states of the converter topology.

[0047] Optionally, the value function solving unit is specifically used for:

[0048] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0049] The converter switching state corresponding to the minimum value of the value function is determined as the optimal solution.

[0050] Optionally, the value function solving unit is specifically used for:

[0051] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0052] Add constraints to the value function;

[0053] Under the constraints of the stated constraints, the optimal solution of the value function in each of the stated control cycles is determined.

[0054] Optionally, the constraints include at least one of the following:

[0055] The duty cycle corresponding to the switching state of the converter has the smallest fluctuation value in the adjacent control cycle, and the duty cycle ranges from (0,1).

[0056] The target preset parameter value has the smallest fluctuation value in adjacent control cycles, and the target preset parameter value is the target input current;

[0057] The input voltage fluctuation is minimized in adjacent control cycles;

[0058] The input power fluctuation is minimized in adjacent control cycles.

[0059] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0060] This invention discloses a fuel cell converter control method. By dividing the given preset parameter value in the control command into target preset parameter values ​​for N control cycles, the input preset parameter value of the converter, such as the input current, linearly reaches the given value. Simultaneously, a multi-step prediction method is employed to calculate the predicted preset parameter values ​​corresponding to different converter switching states within each control cycle based on the fuel cell's IV curve. A value function is constructed based on the target preset parameter values ​​and the predicted preset parameter values. The optimal solution of the value function in each control cycle is determined and executed. This improves the converter's dynamic response capability, avoids abrupt changes in the converter's input preset parameter values, and thus avoids abrupt changes in the fuel cell's output preset parameter values, such as abrupt changes in the converter's input current, and thus avoids abrupt changes in the fuel cell's output current. This reduces damage to the fuel cell and extends its service life. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0062] Figure 1 This is a schematic diagram of the structure of a fuel cell system;

[0063] Figure 2 This is a schematic flowchart of a fuel cell converter control method disclosed in an embodiment of the present invention;

[0064] Figure 3 This is a schematic flowchart of a portion of a fuel cell converter control method disclosed in an embodiment of the present invention;

[0065] Figure 4 This is a schematic diagram of a control cycle division disclosed in an embodiment of the present invention;

[0066] Figure 5 This is a schematic diagram of a boost circuit disclosed in an embodiment of the present invention;

[0067] Figure 6 This is a schematic diagram of a two-way parallel boost circuit disclosed in an embodiment of the present invention;

[0068] Figure 7 This is a schematic diagram of the structure of a fuel cell converter control device disclosed in an embodiment of the present invention. Detailed Implementation

[0069] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] The inventors discovered through research that most current fuel cell converter control methods involve closed-loop control of the converter's output current. While this approach is simple in structure, it suffers from poor dynamic response. Furthermore, an increase in the converter's output current can cause sudden changes in the input current, and other disturbances can easily lead to current oscillations, significantly damaging the fuel cell. Additionally, traditional control systems are complex, making regulator parameter tuning difficult.

[0071] To address the shortcomings of the prior art, this invention provides a fuel cell converter control method and apparatus, applicable to converters, which can be DC converters or inverters. DC converters can be boost, buck, etc., and this invention does not specifically limit them. By dividing the given preset parameter value in the control command into target preset parameter values ​​for N control cycles, the input preset parameter value of the converter, such as the input current, linearly reaches the given value. Simultaneously, a multi-step prediction method is employed to calculate the predicted preset parameter values ​​corresponding to different converter switching states within each control cycle based on the fuel cell's IV curve. A value function is constructed based on the target preset parameter value and the predicted preset parameter value. The optimal solution of the value function in each control cycle is determined and executed, improving the converter's dynamic response capability and avoiding abrupt changes in the converter's input preset parameter value, i.e., avoiding abrupt changes in the fuel cell's output preset parameter value, such as avoiding abrupt changes in the converter's input current, i.e., avoiding abrupt changes in the fuel cell's output current, thereby reducing damage to the fuel cell and extending its service life.

[0072] For details, please refer to Figure 2 The fuel cell converter control method disclosed in this embodiment of the invention includes the following steps:

[0073] S101: Upon receiving a control command, divide the given preset parameter value in the control command into target preset parameter values ​​for N control cycles based on the current input preset parameter value;

[0074] Control commands can be sent from a host computer, BMS (Battery Management System), etc. The control commands include given preset parameter values, which are set according to load requirements.

[0075] The preset parameter value can be either a current value or a power value; this invention does not impose any specific limitation.

[0076] The given preset parameter value is divided into target preset parameter values ​​for N control cycles, where N is a positive integer. The rate of change of the target preset parameter value in each control cycle is less than the maximum rate of change of the preset parameter value allowed by the fuel cell. This ensures that the input preset parameter value of the converter, such as the input current, reaches the given value linearly within N control cycles, thus avoiding sudden changes in the converter input current, which in turn avoids sudden changes in the fuel cell output current.

[0077] Specifically, taking the preset parameter value as the current value as an example, the target preset parameter value can be calculated using the following formula:

[0078] I ref (k+1)=I in (k)+(I inref -I in (k)) / N

[0079] Among them, I ref (k+1) is the target preset parameter value for the (k+1)th control cycle, I inref Given a preset parameter value, I in (k) represents the preset input parameter value for the k-th control cycle. When k = 1, I in (k) represents the current input preset parameter value.

[0080] S102: Using a multi-step prediction method, based on the IV curve of the fuel cell, the predicted preset parameter values ​​corresponding to different converter switching states in each control cycle are calculated.

[0081] The calculation of the predicted preset parameter values ​​corresponding to different converter switching states within each control cycle can be performed online or offline. Offline calculation is the preferred implementation method compared to online calculation.

[0082] Please see Figure 3 This embodiment provides an optional method for calculating preset parameter values, including the following steps:

[0083] S201: Divide the control cycle into M sub-cycles, where M is a positive integer;

[0084] The control period is the prediction period, which can be the switching period Ts. Please refer to [link / reference]. Figure 4 A switching cycle Ts is divided into M parts, each of which is a sub-cycle. These parts are arranged in the order of switching to avoid the situation of switching on and off intermittently, thus reducing switching losses.

[0085] S202: Construct discrete models according to different converter switching states, with each sub-cycle in the discrete model corresponding to its respective converter switching state.

[0086] The converter can have multiple switching states within a single control cycle, with each sub-cycle corresponding to its own converter switching state, such as... Figure 4 The first M / 2 sub-cycles are in the on state, and the next M / 2 sub-cycles are in the off state. Alternatively, the first 2 sub-cycles can be in the on state, and the next M-2 sub-cycles can be in the off state. Other states are also possible, but they will not be enumerated here.

[0087] S203: Using a multi-step prediction method, based on the IV curve of the fuel cell, the predicted preset parameter values ​​corresponding to each discrete model in each control cycle are calculated offline.

[0088] There is a DC-DC converter between the fuel cell and the load, and the DC-DC converter is... Figure 5 Taking the boost circuit shown as an example, at time λ, when Q1 is turned on:

[0089] I in (λ+1)=ι / L*V in (λ)+I in (λ)

[0090] When Q1 is disconnected:

[0091] I in (λ+1)=ι / L*(V o (λ)-V in (λ))+I in (λ)

[0092] At time λ+1, when Q1 is turned on:

[0093] I in (λ+2)=ι / L*V in (λ+1)+I in (λ+1)

[0094] When Q1 is disconnected:

[0095] I in (λ+2)=ι / L*(Vo (λ+1)-V in (λ+1))+I in (λ+1)

[0096] Among them, I in (λ+1) represents the preset prediction parameter value at time λ+1, V in (λ+1) is the input voltage at time λ+1, V o (λ+1) represents the output voltage at time λ+1, L represents the inductance parameter value of the Boost circuit, and V in (λ) represents the input voltage at time λ, V o (λ) is the output voltage at time λ, I in (λ+2) represents the preset parameter value for prediction at time λ+2.

[0097] Until the Mth sub-cycle, since the IV curve of the fuel cell has been imported, the input voltage value can be determined by the predicted input current value. The output voltage value is sampled once every Ts cycle, or once every integer multiple of Ts cycles. Using a multi-step prediction method, the values ​​corresponding to different switching states are calculated offline.

[0098] Where λ represents the λth sub-cycle, and ι=Ts / M is the sub-cycle time predicted by the model.

[0099] Taking the preset parameter value as the current value as an example, since the output voltage of a fuel cell is related to its own output current, by importing the IV curve of the fuel cell and querying the discrete calculation results, the I value can be found. in Substituting the corresponding Vin into the discrete model of the converter, we can obtain the predicted input current for each discrete model in each control cycle.

[0100] The converter can be a single converter or a multi-stage parallel converter. In practical applications, based on the converter's topology, the different switching states corresponding to the topology can be determined, and the corresponding state equations for each switching state can be established. When the converter uses a multi-stage parallel connection, discrete models are constructed based on the different switching states of the converter, including: determining the switching states of the multi-stage parallel connection based on the converter's topology, and establishing the corresponding state equations for each switching state.

[0101] by Figure 6 Taking the two-way parallel boost as an example, there are four different switch states: 1 represents closed, and 0 represents open. That is, S... Q1 =1, S Q2 =1; S Q1 =0, S Q2 =1; S Q1 =1, S Q2 =0; SQ1 = 0, S Q2 = 0; Construct a prediction model according to different switch states.

[0102] When S Q1 = 1, S Q2 = 1;

[0103] I L1 (λ + 1) = ι / L1 * V in (λ) + I L1 (λ)

[0104] I L2 (λ + 1) = ι / L2 * V in (λ) + I L2 (λ)

[0105] When S Q1 = 0, S Q2 = 1;

[0106] I L1 (λ + 1) = ι / L1 * (V o (λ) - V in (λ)) + I L1 (λ)

[0107] I L2 (λ + 1) = ι / L2 * V in (λ) + I L2 (λ)

[0108] When S Q1 = 1, S Q2 = 0;

[0109] I L1 (λ + 1) = ι / L1 * V in (λ) + I L1 (λ)

[0110] I L2 (λ + 1) = ι / L2 * (V o (λ) - V in (λ)) + I L2 (λ)

[0111] When S Q1 = 0, S Q2 = 0;

[0112] I L1 (λ + 1) = ι / L1 * (V o (λ) - V in (λ)) + I L1 (λ)

[0113] I L2(λ+1)=ι / L2*(V o (λ)-V in (λ))+I L2 (λ)

[0114] When there are more parallel branches, the same method can be used for construction, which will not be elaborated here.

[0115] S103: Construct a value function based on the target preset parameter value and the predicted preset parameter value, and determine the optimal solution of the value function in each control cycle;

[0116] The following is one possible value function:

[0117] g(k+1)=|I ref (k+1)-I in (k+1)|;

[0118] Where g(k+1) is the value function value of the (k+1)th control cycle, I ref (k+1), I in (k+1) represent the target preset parameter value and the predicted preset parameter value of the converter in the (k+1)th control cycle, respectively. in (k+1) is the above I in (M).

[0119] The system calculates the predicted preset parameter values ​​for different switching states of all converters offline, and then selects the optimal solution based on the value function using a lookup table method, which is the solution that minimizes the value function. This avoids excessive computation time for model prediction and solution finding.

[0120] Similarly, other constraints can be added to the value function, such as an output voltage limit to control the output voltage. The value function is as follows:

[0121] g(k+1)=|I ref (k+1)-I in (k+1)|+w|V ref (k+1)-V o (k+1)|

[0122] Where w is the weight, V ref (k+1) is related to I ref (k+1) corresponds to the target output voltage.

[0123] Optionally, constraints can be added to the value function to determine the optimal solution of the value function in each control cycle under the constraints.

[0124] The constraints include at least one of the following:

[0125] The fluctuation value of the duty cycle corresponding to the converter switch state is minimized in adjacent control cycles;

[0126] The fluctuation value of the target preset parameter value is minimized in adjacent control cycles, and the target preset parameter value is the target input current;

[0127] The fluctuation value of the input voltage is minimized in adjacent control cycles;

[0128] The fluctuation value of the input power is minimized in adjacent control cycles.

[0129] Among them, the duty cycle d corresponding to the converter switch state, that is, the ratio of the conduction time to the switching period, should have the limitation 0 < d < 1. In order to achieve steady-state operation, a target function can be added between d(k + 1) and d(k) for constraint, to avoid large fluctuations in input power or input current due to sudden changes in the duty cycle.

[0130] S104: Sequentially execute the converter control operations corresponding to the optimal solution in each control cycle.

[0131] By sequentially executing the converter control operations corresponding to the optimal solution in each control cycle, the change rate of the input parameters of the converter is made less than the maximum change rate of the output parameters allowed by the fuel cell. For example, the change rate of the input current of the converter is made less than the maximum change rate of the output current allowed by the fuel cell, to avoid sudden changes in the input current of the converter, that is, to avoid sudden changes in the output current of the fuel cell, thereby reducing the damage to the fuel cell and extending the service life of the fuel cell.

[0132] Based on a fuel cell converter control method disclosed in the above embodiments, this embodiment correspondingly discloses a fuel cell converter control device, which is applied to the converter. Please refer to Figure 7 , the device includes:

[0133] A given preset parameter value division unit 701, configured to divide the given preset parameter value in the control instruction into target preset parameter values for N control cycles according to the current input preset parameter value when receiving a control instruction, where N is a positive integer, and the change rate of the target preset parameter value in each control cycle is less than the maximum preset parameter value change rate allowed by the fuel cell;

[0134] A preset parameter value prediction unit 702, configured to calculate the predicted preset parameter values corresponding to different converter switch states in each control cycle by using a multi-step prediction method according to the IV curve of the fuel cell;

[0135] A value function solving unit 703, configured to construct a value function based on the target preset parameter value and the predicted preset parameter value, and determine the optimal solution of the value function in each control cycle;

[0136] The converter control unit 704 is used to sequentially execute the converter control operation corresponding to the optimal solution in each control cycle.

[0137] Optionally, the preset parameter value is either the current value or the power value.

[0138] Optionally, the given preset parameter value division unit 701 is specifically used for:

[0139] Calculate the difference between the given preset parameter value and the preset parameter value of the current control cycle, and calculate the ratio of the difference to N, where the preset parameter value of the current control cycle is the current input preset parameter value;

[0140] The sum of the current input preset parameter value and the ratio is determined as the target preset parameter value for the next control cycle.

[0141] Optionally, the preset parameter value prediction unit 702 includes:

[0142] The sub-cycle division sub-unit is used to divide the control cycle into M sub-cycles, where M is a positive integer;

[0143] Discrete model construction sub-units are used to construct discrete models according to different converter switching states, wherein each sub-cycle in the discrete model corresponds to its respective converter switching state.

[0144] The offline calculation subunit is used to calculate the predicted preset parameter values ​​corresponding to each discrete model in each control cycle based on the IV curve of the fuel cell using a multi-step prediction method.

[0145] Optionally, the discrete model construction sub-unit is specifically used to determine the state equations corresponding to different switching states of the converter topology.

[0146] Optionally, the value function solving unit 703 is specifically used for:

[0147] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0148] The converter switching state corresponding to the minimum value of the value function is determined as the optimal solution.

[0149] Optionally, the value function solving unit 703 is specifically used for:

[0150] The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function;

[0151] Add constraints to the value function;

[0152] Under the constraints of the stated constraints, the optimal solution of the value function in each of the stated control cycles is determined.

[0153] Optionally, the constraints include at least one of the following:

[0154] The duty cycle corresponding to the switching state of the converter has the smallest fluctuation value in the adjacent control cycle, and the duty cycle ranges from (0,1).

[0155] The target preset parameter value has the smallest fluctuation value in adjacent control cycles, and the target preset parameter value is the target input current;

[0156] The input voltage fluctuation is minimized in adjacent control cycles;

[0157] The input power fluctuation is minimized in adjacent control cycles.

[0158] This embodiment discloses a fuel cell converter control device. By dividing the given preset parameter value in the control command into target preset parameter values ​​for N control cycles, the input preset parameter value of the converter, such as the input current, linearly reaches the given value. Simultaneously, a multi-step prediction method is adopted to calculate the predicted preset parameter value corresponding to different converter switching states in each control cycle based on the IV curve of the fuel cell. A value function is constructed based on the target preset parameter value and the predicted preset parameter value. The optimal solution of the value function in each control cycle is determined and executed, thereby improving the dynamic response capability of the converter and avoiding abrupt changes in the input preset parameter value of the converter, that is, avoiding abrupt changes in the output preset parameter value of the fuel cell, such as avoiding abrupt changes in the input current of the converter, that is, avoiding abrupt changes in the output current of the fuel cell. This reduces damage to the fuel cell and extends the service life of the fuel cell.

[0159] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0160] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0161] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0162] The above embodiments can be combined arbitrarily. The descriptions of the disclosed embodiments and the features recorded in the embodiments of this specification can be substituted or combined with each other, so that those skilled in the art can implement or use this application.

[0163] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a fuel cell converter, characterized in that, Applied to a converter, the method includes: Upon receiving a control command, the given preset parameter value in the control command is divided into target preset parameter values ​​for N control cycles based on the current input preset parameter value, where N is a positive integer. The rate of change of the target preset parameter value in each control cycle is less than the maximum rate of change of the preset parameter value allowed by the fuel cell. A multi-step prediction method is adopted to calculate the predicted preset parameter values ​​corresponding to different converter switching states in each control cycle based on the IV curve of the fuel cell. A value function is constructed based on the target preset parameter value and the prediction preset parameter value, and the optimal solution of the value function is determined in each control cycle; The converter control operation corresponding to the optimal solution is executed sequentially in each control cycle. The multi-step prediction method, based on the IV curve of the fuel cell, calculates the predicted preset parameter values ​​corresponding to different converter switching states within each control cycle, including: The control cycle is divided into M sub-cycles, where M is a positive integer; Discrete models are constructed based on different converter switching states, and each sub-cycle in the discrete model corresponds to its respective converter switching state. A multi-step prediction method is adopted, and the predicted preset parameter values ​​corresponding to each discrete model in each control cycle are calculated offline based on the IV curve of the fuel cell.

2. The method according to claim 1, characterized in that, The preset parameter value is either the current value or the power value.

3. The method according to claim 2, characterized in that, The step of dividing the given preset parameter value in the control command into N control cycles based on the current input preset parameter value includes: Calculate the difference between the given preset parameter value and the preset parameter value of the current control cycle, and calculate the ratio of the difference to N, where the preset parameter value of the current control cycle is the current input preset parameter value; The sum of the current input preset parameter value and the ratio is determined as the target preset parameter value for the next control cycle.

4. The method according to claim 1, characterized in that, The construction of discrete models based on different converter switching states includes: Based on the converter's topology, determine the different switching states corresponding to the topology and establish the corresponding state equations for each switching state.

5. The method according to claim 2, characterized in that, Constructing a value function based on the target preset parameter value and the prediction preset parameter value, and determining the optimal solution of the value function in each control cycle, including: The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function; The converter switching state corresponding to the minimum value of the value function is determined as the optimal solution.

6. The method according to claim 2, characterized in that, Constructing a value function based on the target preset parameter value and the prediction preset parameter value, and determining the optimal solution of the value function in each control cycle, including: The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function; Add constraints to the value function; Under the constraints of the stated constraints, the optimal solution of the value function in each of the stated control cycles is determined.

7. The method according to claim 6, characterized in that, The constraints include at least one of the following: The duty cycle corresponding to the switching state of the converter has the smallest fluctuation value in the adjacent control cycle, and the duty cycle ranges from (0,1). The target preset parameter value has the smallest fluctuation value in adjacent control cycles, and the target preset parameter value is the target input current; The input voltage fluctuation is minimized in adjacent control cycles; The input power fluctuation is minimized in adjacent control cycles.

8. A fuel cell converter control device, characterized in that, Applied to a converter, the device includes: A preset parameter value division unit is provided to divide the given preset parameter value in the control command into target preset parameter values ​​for N control cycles based on the current input preset parameter value when a control command is received. N is a positive integer, and the rate of change of the target preset parameter value in each control cycle is less than the maximum rate of change of the preset parameter value allowed by the fuel cell. The preset parameter value prediction unit is used to calculate the predicted preset parameter values ​​corresponding to different converter switching states in each control cycle based on the IV curve of the fuel cell using a multi-step prediction method. The value function solving unit is used to construct a value function based on the target preset parameter value and the prediction preset parameter value, and to determine the optimal solution of the value function in each control cycle; A converter control unit is used to sequentially execute the converter control operation corresponding to the optimal solution in each control cycle; The preset parameter value prediction unit includes: The sub-cycle division sub-unit is used to divide the control cycle into M sub-cycles, where M is a positive integer; Discrete model construction sub-units are used to construct discrete models according to different converter switching states, wherein each sub-cycle in the discrete model corresponds to its respective converter switching state. The offline calculation subunit is used to calculate the predicted preset parameter values ​​corresponding to each discrete model in each control cycle based on the IV curve of the fuel cell using a multi-step prediction method.

9. The apparatus according to claim 8, characterized in that, The preset parameter value is either the current value or the power value.

10. The apparatus according to claim 9, characterized in that, The given preset parameter value division unit is specifically used for: Calculate the difference between the given preset parameter value and the preset parameter value of the current control cycle, and calculate the ratio of the difference to N, where the preset parameter value of the current control cycle is the current input preset parameter value; The sum of the current input preset parameter value and the ratio is determined as the target preset parameter value for the next control cycle.

11. The apparatus according to claim 8, characterized in that, The discrete model construction sub-unit is specifically used to determine the state equations corresponding to different switching states of the converter topology.

12. The apparatus according to claim 9, characterized in that, The value function solving unit is specifically used for: The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function; The converter switching state corresponding to the minimum value of the value function is determined as the optimal solution.

13. The apparatus according to claim 9, characterized in that, The value function solving unit is specifically used for: The difference function between the target preset parameter value and the predicted preset parameter value is determined as the value function; Add constraints to the value function; Under the constraints of the stated constraints, the optimal solution of the value function in each of the stated control cycles is determined.

14. The apparatus according to claim 13, characterized in that, The constraints include at least one of the following: The duty cycle corresponding to the switching state of the converter has the smallest fluctuation value in the adjacent control cycle, and the duty cycle ranges from (0,1). The target preset parameter value has the smallest fluctuation value in adjacent control cycles, and the target preset parameter value is the target input current; The input voltage fluctuation is minimized in adjacent control cycles; The input power fluctuation is minimized in adjacent control cycles.

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