Reversible solid oxide battery temperature control method and device

Abstract

The invention provides a reversible solid oxide battery temperature control method and device, and belongs to the field of battery safety control, and the method comprises the steps: obtaining a demand load current of a reversible solid oxide battery to be controlled, determining a battery working mode, a corresponding preset reference temperature track and an optimal efficiency point group according to the demand load current, and obtaining a control result; determining a feedforward control signal according to the required load current, a preset reference temperature track and the optimal efficiency point group; and the real-time air inlet temperature of the reversible solid oxide battery to be controlled is obtained, the input control quantity and the predicted air inlet temperature are obtained through prediction according to the preset reference temperature track and the preset state-space equation, and error correction is conducted on the input control quantity according to the predicted air inlet temperature and the real-time air inlet temperature to obtain a feedback control signal. Through a control scheme combining feedforward control and feedback control, the control signal can be quickly and accurately adjusted, the temperature control efficiency of the reversible solid oxide battery is effectively improved, and the operation safety of the battery is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of battery safety control, and in particular to a reversible solid oxide battery temperature control method and device. Background Art

[0002] RSOC (Reversible solid oxide cell) is a new type of power generation and energy storage technology that combines the two operating modes of SOFC (Solid Oxide Fuel Cell) and SOE (Solid oxide electrolysis cell). It can realize reversible switching between SOFC and SOE modes according to user needs. However, when the battery mode is switched, there are thermal changes in the reversible electrochemical reactions occurring in the two modes, which can easily cause transient temperature differences between the two poles of the battery stack and pose a safety hazard. In practical applications, controlling the RSOC battery to operate within a certain range of temperatures and adjusting the system temperature in time when switching modes is the basis for ensuring the safe operation of RSOC.

[0003] The traditional battery temperature control method is to control the temperature of the RSOC battery through the PID method. However, when the PID control switches to the RSOC battery mode, serious temperature overshoot is prone to occur, and the dynamic process of control is relatively long, making it difficult to ensure the control efficiency and temperature safety of the system.

[0004] Therefore, the existing battery temperature control method has the technical problems of being prone to serious temperature overshoot, and the dynamic control process is time-consuming, making it difficult to ensure the control efficiency and temperature safety of the system, which needs to be improved. Summary of the invention

[0005] In view of this, it is necessary to provide a reversible solid oxide battery temperature control method and device to solve the technical problems existing in the prior art that severe temperature overshoot is prone to occur, the dynamic control process is time-consuming, and it is difficult to ensure the control efficiency and temperature safety of the system.

[0006] In order to solve the above problems, on the one hand, the present invention provides a reversible solid oxide battery temperature control method, which is used to adjust the control signal of the battery stack temperature control unit in the reversible solid oxide battery to be controlled to perform temperature control when the working mode of the reversible solid oxide battery to be controlled is switched, and the control signal includes a feedforward control signal and a feedback control signal. The method includes: Obtaining a required load current of a reversible solid oxide battery to be controlled, determining a battery operation mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determining a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; The real-time intake temperature of the reversible solid oxide battery to be controlled is obtained, and the input control amount and the predicted intake temperature are predicted according to the preset reference temperature trajectory and the preset state space equation. The input control amount is error corrected according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

[0007] In one possible implementation, the stack temperature control unit includes gas pipelines, heating rods, and bypass valves that are respectively arranged at the two poles of the reversible solid oxide battery and are independent of each other at both ends, and the control signal includes the heating rod power and the bypass valve opening.

[0008] In a possible implementation, the battery operation mode includes a fuel cell operation mode and an electrolytic cell operation mode, and the preset reference temperature trajectory includes a fuel cell reference temperature trajectory and an electrolytic cell reference temperature trajectory.

[0009] In a possible implementation, the preset reference temperature trajectory and the optimal efficiency point group are obtained by traversing and optimizing the operating parameters of the reversible solid oxide battery to be controlled, and the traversing and optimizing the operating parameters of the reversible solid oxide battery to be controlled includes: The load current, reactant utilization rate, air excess ratio, reactant hydrogen-water ratio and inlet temperature of the reversible solid oxide battery to be controlled are traversed according to the preset discrete accuracy to obtain the system efficiency under each working condition; The system efficiency under each working condition is compared to obtain the optimal efficiency point and reference temperature under each load current, an optimal efficiency point group is obtained according to each optimal efficiency point, and a preset reference temperature trajectory is obtained according to each reference temperature.

[0010] In a possible implementation, determining a feedforward control signal according to a required load current, a preset reference temperature trajectory, and an optimal efficiency point group includes: Determine a reference temperature according to a required load current and a preset reference temperature trajectory, and determine an optimal efficiency point according to the required load current and an optimal efficiency point group; A feedforward control signal is determined according to the reference temperature and the optimum efficiency point.

[0011] In a possible implementation, the preset state space equation is obtained by simulating the battery temperature control, and the battery temperature control simulation includes: Construct a heat transfer model for the reversible solid oxide battery to be controlled; A random seed control quantity is set, and an output step response of the stack heat exchange model is performed according to the random seed control quantity to obtain simulated output data of the stack heat exchange model. A preset state space equation is constructed according to the random seed control quantity and the simulated output data.

[0012] In a possible implementation, a heat transfer model of a battery stack of a reversible solid oxide battery to be controlled is constructed, including: Based on the law of conservation of energy, a heat exchange model and a heat control model of the reversible solid oxide battery to be controlled are constructed, and a heat exchange model of the battery stack is obtained according to the heat exchange model and the heat control model; Among them, the heat exchange model includes the exhaust gas pipeline energy conservation equation, the exhaust gas energy conservation equation, the air pipeline energy conservation equation, the air energy conservation equation, the hydrogen pipeline energy conservation equation and the hydrogen energy conservation equation, and the thermal control model includes the heating rod thermal control model and the bypass valve thermal control model.

[0013] In a possible implementation, the input control variable and the predicted intake air temperature are predicted according to a preset reference temperature trajectory and a preset state space equation, including: The input control quantity is obtained by dynamically solving the model predictive control method according to the preset reference temperature trajectory; The predicted intake air temperature is determined based on a preset state space equation and an input control variable.

[0014] In a possible implementation, error correction is performed on the input control variable according to the predicted intake air temperature and the real-time intake air temperature to obtain a feedback control signal, including: determining a real-time control error based on the predicted intake air temperature and the real-time intake air temperature; The future time error is obtained by weighted calculation based on the real-time control error, and the input control amount is corrected based on the future time error to obtain a feedback control signal.

[0015] On the other hand, the present invention also provides a reversible solid oxide battery temperature control device, which is used to adjust the control signal of the battery stack temperature control unit in the reversible solid oxide battery to be controlled to perform temperature control when the working mode of the reversible solid oxide battery to be controlled is switched, and the control signal includes a feedforward control signal and a feedback control signal. The reversible solid oxide battery temperature control device includes: A feedforward control unit, used to obtain a required load current of the reversible solid oxide battery to be controlled, determine a battery operation mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determine a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; A feedback control unit is used to obtain the real-time intake temperature of the reversible solid oxide battery to be controlled, predict the input control amount and the predicted intake temperature according to a preset reference temperature trajectory and a preset state space equation, and perform error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

[0016] The beneficial effect of the present invention is that the reversible solid oxide battery temperature control method provided by the embodiment of the present invention first obtains the required load current of the reversible solid oxide battery to be controlled, determines the battery operation mode and the corresponding preset reference temperature trajectory and optimal efficiency point group according to the required load current, and determines the feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; then obtains the real-time intake temperature of the reversible solid oxide battery to be controlled, predicts the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and performs error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain the feedback control signal. The present invention can quickly and accurately adjust the control signal by combining the control scheme of feedforward control and feedback control, effectively improve the temperature control efficiency of the reversible solid oxide battery, thereby improving the temperature overshoot and ensuring the safe operation of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic flow chart of an embodiment of a temperature control method for a reversible solid oxide battery provided by the present invention; Figure 2 A schematic diagram of a process of traversing and optimizing operating parameters according to an embodiment of the present invention; Figure 3 A schematic diagram of a flow chart of determining a feedforward control signal according to an embodiment of the present invention; Figure 4 A schematic diagram of a process for constructing a preset state space equation according to an embodiment of the present invention; Figure 5 A schematic diagram of a flow chart of predicting an input control amount and predicting an intake air temperature according to an embodiment of the present invention; Figure 6 A schematic diagram of a process of error correction according to an embodiment of the present invention; Figure 7 A schematic structural diagram of an embodiment of a reversible solid oxide battery temperature control device provided by the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] In the description of the embodiments of the present invention, unless otherwise specified, "multiple" means two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone.

[0021] The descriptions of "first", "second", etc. involved in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the technical features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] The present invention provides a reversible solid oxide battery temperature control method and device, which are described below respectively.

[0024] Figure 1 A schematic flow chart of an embodiment of the temperature control method for a reversible solid oxide battery provided by the present invention is as follows: Figure 1 As shown, the reversible solid oxide battery temperature control method includes: S101, obtaining a required load current of a reversible solid oxide battery to be controlled, determining a battery operation mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determining a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; S102, obtaining the real-time intake temperature of the reversible solid oxide battery to be controlled, predicting the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and performing error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

[0025] Compared with the prior art, the reversible solid oxide battery temperature control method provided in the embodiment of the present invention first obtains the required load current of the reversible solid oxide battery to be controlled, determines the battery operation mode and the corresponding preset reference temperature trajectory and optimal efficiency point group according to the required load current, and determines the feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; then obtains the real-time intake temperature of the reversible solid oxide battery to be controlled, predicts the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and performs error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain the feedback control signal. The present invention can quickly and accurately adjust the control signal by combining the control scheme of feedforward control and feedback control, effectively improve the temperature control efficiency of the reversible solid oxide battery, thereby improving the temperature overshoot and ensuring the safe operation of the battery.

[0026] In some embodiments of the present invention, the stack temperature control unit includes gas pipelines, heating rods and bypass valves which are respectively arranged at the two poles of the reversible solid oxide battery and are independent of each other at both ends, and the control signal includes the heating rod power and the bypass valve opening.

[0027] Specifically, in order to obtain a better temperature control effect, in the embodiment, the temperature control unit of the battery stack is respectively provided with independent gas pipelines at the two poles of the reversible solid oxide battery. The independent gas pipelines can make the gas flow temperatures of the electrodes on both sides of the battery stack independent of each other and uncoupled from each other. The independent gas pipelines on both sides are respectively provided with inlet heating rods and bypass valves to control the inlet temperature of the battery stack, thereby adjusting the heat exchange on the air side and the reactant side of the reversible solid oxide battery. For the heating rod, the embodiment adjusts the inlet temperature by controlling the power of the heating rod, and for the bypass valve, the embodiment adjusts the inlet temperature by controlling the ratio of the hot end gas and the cold end gas during the battery operation by adjusting the opening of the bypass valve, wherein the cold end gas does not pass through the heat exchanger inside the reversible solid oxide battery system, and the hot end gas passes through the heat exchanger inside the reversible solid oxide battery system. The embodiment adjusts the power of the heating rod and the opening of the inlet valve by combining feedforward control and feedback control, controls the inlet temperature of the two poles of the battery stack to complete the adjustment process within a certain time, and controls the temperature of the two poles to remain unchanged within a certain range, thereby realizing the temperature control of the reversible solid oxide battery.

[0028] In some embodiments of the present invention, the battery operation mode includes a fuel cell operation mode and an electrolytic cell operation mode, and the preset reference temperature trajectory includes a fuel cell reference temperature trajectory and an electrolytic cell reference temperature trajectory.

[0029] In some embodiments of the present invention, the preset reference temperature trajectory and the optimal efficiency point group are obtained by traversing and optimizing the operating parameters of the reversible solid oxide battery to be controlled. Figure 2FIG. 1 is a flow chart of the operation parameter traversal optimization process of an embodiment of the present invention. Figure 2 As shown, the operating parameters of the reversible solid oxide battery to be controlled are traversed and optimized, including: S201, traversing the load current, reactant utilization rate, air excess ratio, reactant hydrogen-water ratio and inlet temperature of the reversible solid oxide battery to be controlled according to a preset discrete accuracy to obtain the system efficiency under each working condition; S202 , comparing the system efficiency under each working condition to obtain the optimal efficiency point and reference temperature under each load current, obtaining an optimal efficiency point group according to each optimal efficiency point, and obtaining a preset reference temperature trajectory according to each reference temperature.

[0030] Specifically, in the embodiment, the battery operation mode is divided into two operation modes: fuel cell operation mode and electrolytic cell operation mode, and the fuel cell reference temperature trajectory and the electrolytic cell reference temperature trajectory and the corresponding optimal efficiency point group are established by means of discretization, traversal and optimization. Among them, the optimal efficiency point is defined as the operating parameter operation point that satisfies the stack temperature constraint in the RSOC system and the highest efficiency under the current load current.

[0031] In the ergodic optimization process, the load current , reactant utilization , excess air ratio , the ratio of reactants to hydrogen and water and intake air temperature According to the preset discrete precision ( , , 0.05, , ) to traverse and find the operating point group that maximizes the RSOC system efficiency under various working conditions among the operating points that meet the temperature constraints.

[0032] Among them, the maximum two-stage inlet temperature overshoot and the maximum temperature variation range constraints are expressed as:

[0033] in, , are the stack inlet temperature and the stack outlet temperature, , are the reactant side inlet temperature and the air side inlet temperature, To set the stack inlet temperature, is the stack temperature.

[0034] The optimal operating point can be defined as: For SOFC mode, the input point of maximum operating efficiency The evaluation criteria are expressed as:

[0035]

[0036] in Indicates the net battery power, Indicates the stack output power at the current current. Indicates the total electrical power consumed by auxiliary components, is the current load current, is the steady-state output voltage of the stack.

[0037] For SOE mode, the optimal working input point The evaluation criteria are expressed as:

[0038]

[0039] in, represents the battery thermal neutral voltage, Indicates the outlet gas temperature of the reactant (air) side heat exchanger under the current load current, Represents the stack output temperature. Here, the optimal operating point in SOE mode is equivalent to the point of maximum system efficiency.

[0040] In addition, the system efficiency in each mode is defined as:

[0041]

[0042] in, is the lower heating value of hydrogen, which is 241.83 J / mol in the embodiment. represents the molar flow rate of hydrogen consumed in SOFC mode, Indicates the molar flow rate of hydrogen generated in SOE mode.

[0043] The embodiment traverses and optimizes the battery operating parameters through defined constraints and optimal operating points to obtain the optimal efficiency point and reference temperature under each load current, and organizes the optimal efficiency points into an optimal efficiency point group, and constructs the reference temperature into a preset reference temperature trajectory corresponding to the load current.

[0044] In some embodiments of the present invention, Figure 3 FIG. 1 is a flow chart of determining a feedforward control signal according to an embodiment of the present invention. Figure 3 As shown, the feedforward control signal is determined according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group, including: S301, determining a reference temperature according to a required load current and a preset reference temperature trajectory, and determining an optimal efficiency point according to the required load current and an optimal efficiency point group; S303 . Determine a feedforward control signal according to the reference temperature and the optimal efficiency point.

[0045] Specifically, in the feedforward control, the embodiment finds the corresponding reference temperature according to the required load current and the preset reference temperature trajectory, and finds the control parameters of the system's optimal efficiency point according to the required load current and the optimal efficiency point group, including reactant utilization, air excess ratio, reactant hydrogen-water ratio, preset intake molar flow rate, and preset heating rod power. Then, the feedforward control signal of the feedforward controller based on current and temperature is determined according to the reference temperature and the optimal efficiency point.

[0046] Among them, the current feedforward for adjusting the opening of the solenoid valve can be expressed by the formula:

[0047]

[0048] in, Indicates the opening of the solenoid valve on the fuel side, Indicates the opening of the solenoid valve on the air side. Indicates the input current, Indicates the number of cells. represents the utilization rate of reactants, represents the excess air ratio, represents the oxygen mass fraction, is the Faraday constant.

[0049] The temperature feedforward obtained by adjusting the power of the heating rod can be expressed as:

[0050] in, Indicates the power of the heating rods on both sides of the battery stack. Indicates the heating rod sets the heating temperature. Indicates the temperature of the gas before heating. Indicates the heating rod efficiency, is the specific heat of gas, is the molar flow rate of gas.

[0051] In some embodiments of the present invention, the preset state space equation is obtained by simulating the battery temperature control. Figure 4 Schematic diagram of the process of constructing a preset state space equation according to an embodiment of the present invention, such as Figure 4 As shown, the battery temperature control simulation includes: S401, constructing a heat exchange model of a battery stack of a reversible solid oxide battery to be controlled; S402, setting a random seed control amount, performing an output step response on the stack heat exchange model according to the random seed control amount to obtain simulated output data of the stack heat exchange model, and constructing a preset state space equation according to the random seed control amount and the simulated output data.

[0052] In some embodiments of the present invention, a heat exchange model of a reversible solid oxide battery to be controlled is constructed, including: Based on the law of conservation of energy, a heat exchange model and a heat control model of the reversible solid oxide battery to be controlled are constructed, and a heat exchange model of the battery stack is obtained according to the heat exchange model and the heat control model; Among them, the heat exchange model includes the exhaust gas pipeline energy conservation equation, the exhaust gas energy conservation equation, the air pipeline energy conservation equation, the air energy conservation equation, the hydrogen pipeline energy conservation equation and the hydrogen energy conservation equation, and the thermal control model includes the heating rod thermal control model and the bypass valve thermal control model.

[0053] Specifically, the feedback regulator in the embodiment is based on the model predictive control method. In order to achieve accurate and efficient feedback regulation of the control signal of the battery stack temperature, it is necessary to first construct the state space equation of the feedback regulator.

[0054] In the process of constructing the state-space equation, the embodiment first establishes a heat exchange model of the heat exchangers on both sides of the battery stack, as well as a thermal control model of the heating rod and the bypass valve, and forms a battery stack heat exchange model according to the thermal control modules of the heat exchange model.

[0055] The heat exchange model in the embodiment is modeled based on the law of conservation of energy, wherein the energy conservation formula of the exhaust gas pipeline is expressed as:

[0056] in, represents the convective heat of the exhaust gas, represents the conduction heat between the front and rear nodes of the pipeline, Expressed as tail gas pipeline specific heat, Indicates the exhaust pipe node quality.

[0057] The exhaust gas energy conservation formula is expressed as:

[0058] in, Indicates the heat conduction in the exhaust pipe. Indicates that the air duct conducts heat. Indicates that the hydrogen pipeline conducts heat. Indicates the heat carried by the inlet exhaust gas, Indicates the heat carried by the outlet exhaust gas, is the specific heat of gas, Indicates the molar flow rate of exhaust gas.

[0059] The energy conservation formula for air ducts is expressed as:

[0060] in, represents the exhaust duct convection heat, It represents the heat conduction of the pipelines at the front and rear nodes. represents the convection heat of the air in the duct, represents the specific heat of air duct, Indicates the air duct node mass.

[0061] The air energy conservation formula is expressed as:

[0062] in, Indicates that the air duct conducts heat. Indicates the intake heat carried by air transmission, Indicates the heat carried by the air. is the specific heat of air, Represents the molar flow rate of air.

[0063] The energy conservation formula of the fuel pipeline is expressed as:

[0064] in, Exhaust convection heat, It represents the heat conduction of the pipelines at the front and rear nodes. represents the convection heat of the air in the duct, represents the specific heat of the fuel pipeline, Represents the quality of the fuel pipeline node.

[0065] The fuel energy conservation formula is expressed as:

[0066] in, Indicates that the hydrogen pipeline conducts heat. represents the intake heat carried by gas transport, Indicates the heat of the gas carried by the gas transmission. represents the specific heat of fuel, Represents the molar flow rate of fuel.

[0067] Without considering heat dissipation, the heating rod is regarded as a mixed hot gas with a heat source to model the energy conservation equation. The heating rod thermal control model of the heating rods on both sides of the stack can be expressed as:

[0068] in, express , represents the molar flow rate of heated gas, Indicates the total intake heat of the heated gas, Indicates the total heat of the heated gas. Indicates the electrical heating amount of the heating rod.

[0069] The bypass valve separates the gas flow according to the ratio of the bypass valve opening BP, and then mixes the hot end gas with the cold end gas. BP refers to the percentage of the cold end gas in the blower output flow. The temperature after mixing is solved by the law of conservation of energy. The bypass valve thermal control model of the bypass valves on both sides of the stack can be expressed as:

[0070] in, is the isochoric specific heat capacity of gas, represents the gas molar flow rate, Indicates the air conditioning temperature. Indicates the hot air temperature, represents the temperature of the mixed gas, It represents the molar flow rate of gas mixture. represents the molar flow rate of cooling air, It represents the molar flow rate of hot gas.

[0071] After the modeling is completed, the embodiment sets the random seed control amount according to the established model, simulates the output step response of the stack heat exchange model through the simulation program, obtains the simulated output data of the stack heat exchange model, and constitutes the input and output data of the RSOC battery system, and uses the system offline identification method to select the state equation of the appropriate order to identify a state space equation about current-temperature, which is used in the model predictive controller of feedback control. The state space equation can be expressed by the following formula:

[0072]

[0073] The parameters can be expressed as:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] Among them, the measured input quantities MO are: Reactant temperature at the inlet of the stack and stack inlet air temperature The measured interference quantities MD are: current , air side heat exchanger outlet temperature and the outlet temperature of the heat exchanger on the reactant side The reference values ​​ref are: stack reactant side inlet temperature and stack air side intake temperature The controlled quantities MV are: the heating rod power on the reactant side , Air side heating rod power , reactant side bypass valve opening and air side bypass valve opening .

[0083] In some embodiments of the present invention, Figure 5 FIG. 1 is a flow chart of predicting the input control amount and the intake air temperature according to an embodiment of the present invention. Figure 5 As shown, the input control amount and the predicted intake air temperature are predicted according to the preset reference temperature trajectory and the preset state space equation, including: S501, dynamically solving the model predictive control method according to the preset reference temperature trajectory to obtain the input control amount; S502: Determine a predicted intake air temperature according to a preset state space equation and an input control variable.

[0084] Specifically, in the feedback control, the embodiment adopts the model predictive control method for feedback control. As a process control strategy, the model predictive control method achieves global optimal control by dynamically calculating the local optimal solution. In each control cycle, the model predictive control method predicts the next N steps and solves the problem by rolling optimization. The formula of model predictive control can be expressed as:

[0085]

[0086]

[0087] in, represents the reference temperature trajectory, represents the control weight coefficient, represents the prediction interval, represents the control interval, represents the input control quantity, represents the output predicted intake air temperature, Indicates the return value.

[0088] The model predictive control method makes a preliminary prediction of the input and output of the feedback control by referring to the temperature trajectory to obtain the input control variable and the predicted intake temperature.

[0089] In some embodiments of the present invention, Figure 6 FIG. 1 is a flow chart of error correction according to an embodiment of the present invention. Figure 6 As shown, the input control amount is error corrected according to the predicted intake air temperature and the real-time intake air temperature to obtain a feedback control signal, including: S601, determining a real-time control error according to the predicted intake air temperature and the real-time intake air temperature; S602, obtaining a future time error according to a weighted calculation of the real-time control error, and performing error correction on the input control amount according to the future time error to obtain a feedback control signal.

[0090] In order to ensure the accuracy of the final feedback control signal, it is also necessary to perform error correction on the input control quantity. In the error correction process, the internal model of the model predictive control is the state space equation obtained in the previous step, and the future output, that is, the predicted intake temperature, is predicted by the following formula:

[0091] in, Indicated in The predicted intake air temperature under the control variable at a future time, represents the initial predicted intake air temperature under the control variable, represents the control matrix.

[0092] Then the control effect is At time t, the predicted intake air temperature is obtained by the state space equation, and the error between the predicted intake air temperature at this time and the actual intake air temperature measured is used as the feedback correction link. The error at future time is calculated by weighted method to compensate for the error in the model prediction. The corrected feedback control signal is expressed as:

[0093] in, represents the error correction matrix, Represents the amount of input error. Starting from time k, the initial prediction value rolls forward over time.

[0094] The initial prediction can be expressed as:

[0095] in, Represents a shift matrix.

[0096] In addition, in order to verify the effectiveness of the solution of the present invention, the present invention also conducted a temperature control test and compared the test results with those of the traditional PID controller. The specific details are as follows: In the temperature control test, in the case of irregular load current steps, including small current steps, large current steps, and mode switching steps, the PID controller is used in combination with the feedforward feedback of the present invention to control the stack intake temperature to obtain an output response about the stack intake temperature. In the test, the current changes in a cycle of [10A, 20A, 50A, -20A, -50A, 10A] with a step time interval of 1500s. By observing the dynamic process of the stack intake temperature under each load current switching, it can be found that: in the small current step dynamics of [10A, 20A] and [-10A, -20A], the control scheme of the present invention can complete the control within 20s, and the temperature overshoot is <5K, which is within the satisfied constraint range; in the large current step dynamics of [20A, 50A] and [-20A, -50A], the control scheme of the present invention can complete the control within 60s, and there is no excessive temperature overshoot; in the mode switching step dynamics of [50A, -10A] and [-50A, 10A], the control scheme of the present invention can complete the control within 20s, and the temperature overshoot is extremely small, which meets the constraint range. Compared with the problems of large current switching, serious overshoot of mode switching and long dynamic process in the step response of traditional PID control and no control strategy, these problems can be effectively solved in the control scheme designed in the present invention, verifying the feasibility and advantages of the temperature control strategy in the present invention.

[0097] In summary, in order to improve the temperature control efficiency of the reversible solid oxide battery and ensure the safety of the battery when switching the working mode, the present invention first obtains the required load current of the reversible solid oxide battery to be controlled, determines the battery working mode and the corresponding preset reference temperature trajectory and optimal efficiency point group according to the required load current, and determines the feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; then obtains the real-time intake temperature of the reversible solid oxide battery to be controlled, and predicts the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and performs error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain the feedback control signal. The present invention can quickly and accurately adjust the control signal by combining the control scheme of feedforward control and feedback control, effectively improve the temperature control efficiency of the reversible solid oxide battery, thereby improving the temperature overshoot and ensuring the safety of battery operation.

[0098] In order to better implement the reversible solid oxide battery temperature control method in the embodiment of the present invention, based on the reversible solid oxide battery temperature control method, correspondingly, Figure 7 As shown, the present invention also provides a reversible solid oxide battery temperature control device, and the reversible solid oxide battery temperature control device 700 includes: A feedforward control unit 701 is used to obtain a required load current of the reversible solid oxide battery to be controlled, determine a battery operation mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determine a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; The feedback control unit 702 is used to obtain the real-time intake temperature of the reversible solid oxide battery to be controlled, predict the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and perform error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

[0099] The reversible solid oxide battery temperature control device 700 provided in the above embodiment can implement the technical solution described in the above reversible solid oxide battery temperature control method embodiment. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above reversible solid oxide battery temperature control method embodiment, which will not be repeated here.

[0100] The above is a detailed introduction to the reversible solid oxide battery temperature control method and device provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A reversible solid oxide battery temperature control method, characterized in that: When the working mode of the reversible solid oxide battery to be controlled is switched, a control signal of a battery stack temperature control unit in the reversible solid oxide battery to be controlled is adjusted to perform temperature control, wherein the control signal includes a feedforward control signal and a feedback control signal. The method includes: Obtaining a required load current of the reversible solid oxide battery to be controlled, determining a battery operating mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determining a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; The real-time intake temperature of the reversible solid oxide battery to be controlled is obtained, and an input control amount and a predicted intake temperature are predicted according to the preset reference temperature trajectory and the preset state-space equation. The input control amount is error corrected according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

2. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The stack temperature control unit includes gas pipelines, heating rods and bypass valves which are respectively arranged at two poles of the reversible solid oxide battery and are independent of each other at both ends. The control signal includes the heating rod power and the bypass valve opening.

3. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The battery operation mode includes a fuel cell operation mode and an electrolytic cell operation mode, and the preset reference temperature trajectory includes a fuel cell reference temperature trajectory and an electrolytic cell reference temperature trajectory.

4. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The preset reference temperature trajectory and the optimal efficiency point group are obtained by traversing and optimizing the operating parameters of the reversible solid oxide battery to be controlled, and the traversing and optimizing the operating parameters of the reversible solid oxide battery to be controlled includes: The load current, reactant utilization rate, air excess ratio, reactant hydrogen-water ratio and inlet temperature of the reversible solid oxide battery to be controlled are traversed according to a preset discrete accuracy to obtain the system efficiency under each working condition; The system efficiencies under the various working conditions are compared to obtain the optimal efficiency points and reference temperatures under the various load currents, an optimal efficiency point group is obtained based on the optimal efficiency points, and a preset reference temperature trajectory is obtained based on the reference temperatures.

5. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The step of determining the feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group includes: Determine a reference temperature according to the required load current and the preset reference temperature trajectory, and determine an optimal efficiency point according to the required load current and the optimal efficiency point group; A feedforward control signal is determined according to the reference temperature and the optimal efficiency point.

6. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The preset state space equation is obtained by simulating the battery temperature control, and the battery temperature control simulation includes: Constructing a heat exchange model of a battery stack of the reversible solid oxide battery to be controlled; A random seed control amount is set, and an output step response is performed on the stack heat exchange model according to the random seed control amount to obtain simulated output data of the stack heat exchange model, and a preset state space equation is constructed according to the random seed control amount and the simulated output data.

7. The reversible solid oxide battery temperature control method according to claim 6, characterized in that: The step of constructing a heat exchange model of a battery stack of the reversible solid oxide battery to be controlled comprises: Based on the law of conservation of energy, a heat exchange model and a heat control model of the reversible solid oxide battery to be controlled are constructed, and a heat exchange model of the battery stack is obtained according to the heat exchange model and the heat control model; Among them, the heat exchange model includes the exhaust gas pipeline energy conservation equation, the exhaust gas energy conservation equation, the air pipeline energy conservation equation, the air energy conservation equation, the hydrogen pipeline energy conservation equation and the hydrogen energy conservation equation, and the thermal control model includes the heating rod thermal control model and the bypass valve thermal control model.

8. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The step of predicting the input control variable and the predicted intake air temperature according to the preset reference temperature trajectory and the preset state space equation includes: Performing a model predictive control method dynamically solves the input control amount according to the preset reference temperature trajectory; The predicted intake air temperature is determined according to the preset state space equation and the input control variable.

9. The reversible solid oxide battery temperature control method according to claim 1, characterized in that: The step of performing error correction on the input control variable according to the predicted intake air temperature and the real-time intake air temperature to obtain a feedback control signal includes: determining a real-time control error according to the predicted intake air temperature and the real-time intake air temperature; The future time error is obtained by weighted calculation according to the real-time control error, and the input control amount is error corrected according to the future time error to obtain a feedback control signal.

10. A reversible solid oxide battery temperature control device, characterized in that: When the working mode of the reversible solid oxide battery to be controlled is switched, the control signal of the battery stack temperature control unit in the reversible solid oxide battery to be controlled is adjusted to perform temperature control, wherein the control signal includes a feedforward control signal and a feedback control signal. The reversible solid oxide battery temperature control device includes: A feedforward control unit, used to obtain a required load current of the reversible solid oxide battery to be controlled, determine a battery operation mode and a corresponding preset reference temperature trajectory and an optimal efficiency point group according to the required load current, and determine a feedforward control signal according to the required load current, the preset reference temperature trajectory and the optimal efficiency point group; A feedback control unit is used to obtain the real-time intake temperature of the reversible solid oxide battery to be controlled, predict the input control amount and the predicted intake temperature according to the preset reference temperature trajectory and the preset state space equation, and perform error correction on the input control amount according to the predicted intake temperature and the real-time intake temperature to obtain a feedback control signal.

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