Transfer function construction method and system of n-order controller

Abstract

The invention provides a transfer function construction method and system of an n-order controller, and belongs to the field of thermal processes. The method comprises the steps of constructing a transfer function of an n-order controller based on a controlled object model and an initial model of the transfer function of the n-order controller, and performing simulation and experimental testing on the transfer function of the n-order controller; the n-order controller transfer function initial model is constructed based on the PI controller sub-model and the lead link sub-model; if the transfer function of the n-order controller needs to be adjusted and optimized, controller parameters are adjusted, the transfer function of the n-order controller is updated based on the adjusted controller parameters, simulation and experimental testing are carried out based on the updated transfer function of the n-order controller, and the final transfer function of the n-order controller is determined. Therefore, the limitation of the traditional PID in a high-order inertial system is effectively overcome, and a better tracking effect and a better disturbance suppression effect can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of thermal processes, and in particular to a method for constructing a transfer function of an n-order controller, a system for constructing a transfer function of an n-order controller, a machine-readable storage medium and an electronic device. Background Art

[0002] In recent years, Proportional Integration Differentiation (PID) control has become a commonly used feedback control technology in most thermal process systems of thermal power plants. Its core is to eliminate errors through errors and continuously adjust the control signal so that the system output follows the set value. At present, thermal power generating units are developing in the direction of large capacity and multiple parameters, and higher requirements are placed on the control performance of thermal process systems. In addition, thermal process systems in thermal power plants have the characteristics of nonlinearity, large inertia, and large time lag. Equipment wear and changing environmental conditions cause system parameters to change in time, which brings great challenges to the on-site tuning of the control system. The on-site tuning of traditional PID control still mainly adopts ZN tuning and empirical methods. The tuning process consumes a lot of time and the control effect is poor.

[0003] Therefore, there is an urgent need for a control technology with simpler and more practical parameter setting and better control performance to overcome the limitations of traditional PID control in complex thermal processes, thereby promoting the development of thermal power plants in a more efficient and economical direction. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method and system for constructing a transfer function of an n-th order controller, so as to at least solve the problem that the controller parameter tuning process mentioned above takes a lot of time and has poor control effect.

[0005] In order to achieve the above object, the present invention provides a first aspect of a transfer function construction method of an n-order controller, comprising: S110: Determine controller parameters based on a pre-established controlled object model; S120: constructing a transfer function of the n-order controller based on controller parameters and a pre-constructed initial model of the n-order controller transfer function, and performing simulation and experimental tests on the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the initial model of the n-order controller transfer function is constructed based on a PI controller sub-model and a lead link sub-model; S130: Based on the difference between the current simulation results and the experimental test results, determine whether it is necessary to adjust and optimize the transfer function of the n-order controller. If it is necessary to adjust and optimize the transfer function of the n-order controller, adjust the controller parameters, and based on the adjusted controller parameters, update the transfer function of the n-order controller. Simulate and experimentally test the transfer function of the updated n-order controller respectively, and repeat S130 until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, so as to obtain the final transfer function of the n-order controller.

[0006] Optionally, the establishment rules of the above controlled object model include: Carry out mechanism modeling or system identification for high-order inertial thermal process systems to establish a controlled object model; The transfer function of the controlled object model is , is the gain coefficient of the high-order inertia thermal process system, is the time constant of the high-order inertial thermal process system, n is the order of the high-order inertia thermal process system.

[0007] Optionally, the construction rules of the initial model of the above n-order controller transfer function are: The PI controller sub-model and the lead link sub-model are combined in the form of a positive feedback structure to obtain the initial model of the n-order controller transfer function; The initial model of the n-order controller transfer function is: , the leading link sub-model is ;in, , , , is the Laplace operator, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, Determine the order of the leading link, The value of is determined by the order of the controlled object model. is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller, is the closed-loop control system time constant of the PI controller.

[0008] Optionally, the transfer function of the forward channel of the above positive feedback structure is n Step-ahead link , the transfer function of the feedback channel of the positive feedback structure is n Inertia link , after combining the transfer function of the forward path and the transfer function of the feedback path, the external controller gain .

[0009] Optionally, based on the difference between the current simulation result and the experimental test result, it is determined whether the transfer function of the n-order controller needs to be adjusted and optimized. If the transfer function of the n-order controller needs to be adjusted and optimized, the controller parameters are adjusted, including: Compare the current simulation results with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, then n The controller parameters are adjusted by using the parameter tuning rules of the first-order controller; among them, n The parameter tuning rules of the high-order controller are obtained based on the controlled object model.

[0010] Optionally, the controller parameters include controller order n; The above n-order controller parameter tuning rules include: when The smaller the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is less than the first preset value, a high-order inertia thermal process system oscillation will occur; when The larger the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is greater than the second preset value, a high-order inertia thermal process system overshoot will occur; When the controller order n is the same as the order of the controlled object model, it means that the high-order inertia thermal process system has the best tracking effect and anti-disturbance effect; when When the value gradually decreases, based on As the value of the value decreases, the response speed of the high-order inertia thermal process system will gradually increase; in, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, It is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller.

[0011] Optionally, after obtaining the final transfer function of the n-th order controller, the method further includes: The transfer function of the final n-order controller is deployed to the high-order inertia thermal process system, and the n-order controller in the high-order inertia thermal process system is tested according to a preset monitoring cycle to obtain test data; The simulation results, experimental test results and detection data corresponding to the n-order controller are saved in the database.

[0012] A second aspect of the present invention provides a transfer function construction system for an n-order controller, comprising: A controller parameter determination module, used for determining controller parameters based on a pre-established controlled object model; A controller transfer function construction module is used to construct the transfer function of the n-order controller based on the controller parameters and the pre-constructed n-order controller transfer function initial model, and simulate and experimentally test the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the n-order controller transfer function initial model is constructed based on the PI controller sub-model and the lead link sub-model; The controller transfer function adjustment and optimization module is used to determine whether the transfer function of the n-order controller needs to be adjusted and optimized based on the difference between the current simulation results and the experimental test results. If the transfer function of the n-order controller needs to be adjusted and optimized, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated, and simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the controller transfer function adjustment and optimization module is repeatedly executed until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, thereby obtaining the final transfer function of the n-order controller.

[0013] In a third aspect of the present invention, a machine-readable storage medium is provided, on which instructions are stored, and when the instructions are executed by a processor, the processor is configured to execute the transfer function construction method of the n-th order controller.

[0014] In a fourth aspect of the present invention, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the transfer function construction method of the n-th order controller is implemented.

[0015] Through the above technical scheme, a method and system for constructing the transfer function of an n-order controller is provided. According to the pre-established controlled object model, the controller parameters are determined, so that the controller parameters are substituted into the pre-established initial model of the transfer function of the n-order controller to construct the transfer function of the n-order controller, and the transfer function of the n-order controller is simulated to obtain the simulation result. The high-order inertia thermal process system is controlled by the n-order controller to experimentally test the transfer function of the n-order controller to obtain the experimental test result. Among them, the initial model of the transfer function of the n-order controller is constructed based on the PI controller sub-model and the lead link sub-model, so as to realize the transformation of the traditional typical thermal system with n first-order inertia links in series into a new system with arbitrarily configurable closed-loop poles. The combination of the PI controller sub-model and the lead link sub-model solves the problems of the difficulty in setting the existing PID control parameters, the unsatisfactory set value tracking ability and the disturbance suppression ability, thereby overcoming the limitations of traditional PID control in complex thermal processes. Compare the current simulation results with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated, and simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the transfer function of the n-order controller corresponding to the difference between the simulation results and the experimental test results being less than the preset difference threshold is determined as the final transfer function of the n-order controller, thereby ensuring that the final transfer function of the n-order controller has the best control performance. The transfer function of the n-order controller obtained by this method and system is relatively simple and practical in the actual application of parameter tuning, which not only avoids the tuning process from consuming a lot of time, but also improves the control effect of the controller, effectively overcomes the limitations of traditional PID in high-order inertial systems, can obtain better tracking effect and disturbance suppression effect, and parameter tuning is more convenient, which can promote the development of thermal power plants in a more efficient and economical direction.

[0016] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 is a flow chart of a method for constructing a transfer function of an n-order controller provided by an embodiment of the present invention; Figure 2 is a control structure diagram of a controller provided by one embodiment of the present invention; Figure 3is a structural diagram of an n-order controller provided by an embodiment of the present invention; Figure 4 is a comparison chart of the tracking capability of an n-th order controller and a controller setpoint provided by an embodiment of the present invention; Figure 5 is a comparison diagram of an n-order controller and a controller control signal provided by an embodiment of the present invention; Figure 6 is a comparison diagram of the disturbance suppression capability of an n-order controller and a controller provided by an embodiment of the present invention; Figure 7 This is a comparison diagram of control effects under different controller orders provided by an embodiment of the present invention; Figure 8 An embodiment of the present invention provides different Comparison chart of control effects under different values; Fig. 9 An embodiment of the present invention provides different Comparison chart of control effects under different values; Fig.10 An embodiment of the present invention provides different Comparison chart of control effects under different values; Fig.11 It is a flowchart of an implementation process of an n-order controller provided by one embodiment of the present invention; Fig.12 It is a block diagram of a transfer function construction system of an n-order controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0021] Example 1 Figure 1 is a flow chart of a method for constructing a transfer function of an n-order controller provided by an embodiment of the present invention, Fig.11 This is a flowchart of an n-order controller implementation provided by an embodiment of the present invention. Figure 1 and Fig.11 As shown, an embodiment of the present invention provides a method for constructing a transfer function of an n-order controller, comprising: S110: Determine controller parameters based on a pre-established controlled object model; In some implementations of this embodiment, the establishment rules of the above-mentioned controlled object model include: performing mechanism modeling or system identification on the high-order inertia thermal process system to establish the controlled object model; wherein the transfer function of the controlled object model is , is the gain coefficient of the high-order inertia thermal process system, is the time constant of the high-order inertial thermal process system, n is the order of the high-order inertia thermal process system.

[0022] Specifically, the mechanism modeling or system identification of the high-order inertial thermal process system is carried out and the corresponding mathematical model is established. (i.e., the controlled object model). According to the controlled object model, the controller parameters are selected, so that it is convenient to design the n-order controller directly based on the controller parameters. Among them, the controller parameters include (i.e., the gain factor of the PI controller), (i.e. the integral time constant of the PI controller) and (That is, the adjustment coefficient of the time constant of the closed-loop control system of the PI controller).

[0023] S120: constructing a transfer function of the n-order controller based on controller parameters and a pre-constructed initial model of the n-order controller transfer function, and performing simulation and experimental tests on the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the initial model of the n-order controller transfer function is constructed based on a PI controller sub-model and a lead link sub-model; In some implementations of this embodiment, the construction rule of the initial model of the n-order controller transfer function is as follows: the PI controller sub-model and the lead link sub-model are combined in the form of a positive feedback structure to obtain the initial model of the n-order controller transfer function; wherein the initial model of the n-order controller transfer function is , the leading link sub-model is ;in, , , , is the Laplace operator, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, Determine the order of the leading link, The value of is determined by the order of the controlled object model. is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller, is the closed-loop control system time constant of the PI controller.

[0024] Specifically, the method constructs the transfer function rule of the n-order controller by combining the PI controller with the (n-1)-order lead link in the form of a positive feedback structure, and proposes an n-order controller, which can transform the traditional typical thermal system with n first-order inertia links in series into a new system with arbitrarily configurable closed-loop poles. Among them, the PI controller is used to ensure the stability and accuracy of the control, and the (n-1)-order lead link is used to improve the dynamic response speed of the high-order inertia thermal process system. By combining the PI controller with the (n-1)-order lead link, the existing PID control parameter tuning difficulties, set value tracking capability and disturbance suppression capability are solved, thereby overcoming the limitations of traditional PID control in complex thermal processes. Among them, the transfer function form of the (n-1)-order lead link and the lead link sub-model Consistent.

[0025] In some implementations of this embodiment, the transfer function of the forward channel of the positive feedback structure is n Step-ahead link , the transfer function of the feedback channel of the positive feedback structure is n Inertia link , after combining the transfer function of the forward path and the transfer function of the feedback path, the external controller gain .

[0026] Specifically, for the construction of an n-order controller, the setting target of its adjustable parameters is , whose order is consistent with the order n of the high-order inertial thermal process system, and the parameter It is used to arbitrarily configure the closed-loop poles and adjust the response time of the high-order inertia thermal process system. T represents the time constant of the controlled object. ,in It is the adjustment coefficient of the time constant of the closed-loop control system in the controller, and its adjustable range is 0 to 1; is the time constant of the closed-loop control system.

[0027] Lian Li , , and , we can conclude that: ;Will Transformed into a positive feedback structure: ;according to , the transfer function of the forward path of the n-th order controller is the n-th order lead link , the transfer function of the feedback channel is the nth order inertia link , and then connect a controller gain .

[0028] Please refer to Figure 2 , Figure 2 is a control structure diagram of a controller provided by an embodiment of the present invention. For the construction of an n-order controller, the closed-loop transfer function of the system is: ;Will and Substitution , let the integral time be equal to the time constant of the controlled object, that is ,but: ; At this time, the closed-loop system can arbitrarily configure the poles. For the design of the controller, the setting target of its adjustable parameters is , whose order is consistent with the order n of the controlled object model, and the parameter It is used to arbitrarily configure closed-loop poles and adjust the response time of high-order inertia thermal process systems.

[0029] S130: Based on the difference between the current simulation results and the experimental test results, determine whether it is necessary to adjust and optimize the transfer function of the n-order controller. If it is necessary to adjust and optimize the transfer function of the n-order controller, adjust the controller parameters, and based on the adjusted controller parameters, update the transfer function of the n-order controller. Simulate and experimentally test the transfer function of the updated n-order controller respectively, and repeat S130 until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, so as to obtain the final transfer function of the n-order controller.

[0030] In some implementations of this embodiment, the above-mentioned judgment on whether it is necessary to adjust and optimize the transfer function of the n-order controller based on the difference between the current simulation result and the experimental test result, if it is necessary to adjust and optimize the transfer function of the n-order controller, then adjusting the controller parameters includes: comparing the current simulation result and the experimental test result, if the difference between the current simulation result and the experimental test result is greater than a preset difference threshold, then based on n The controller parameters are adjusted by using the parameter tuning rules of the first-order controller; among them, n The parameter tuning rules of the high-order controller are obtained based on the controlled object model.

[0031] Specifically, the transfer function of the n-order controller is constructed according to the controlled object model and control performance requirements, and the nn-order controller parameter tuning rules. Based on the controlled object model, the transfer function of the n-order controller is simulated to obtain simulation results. The designed n-order controller is deployed in the actual high-order inertia thermal process system for testing (i.e., the high-order inertia thermal process system is controlled by the n-order controller), and the current simulation results are compared with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, it indicates that the current simulation results and the experimental test results are quite different, and it is necessary to further refine the mathematical model (i.e., the controlled object model) or fine-tune the n-order controller parameters in combination with the n-order controller parameter tuning rules. Therefore, based on the simulation results and experimental test results, the controller parameters are finely adjusted according to the n-order controller parameter tuning rules to obtain the best control performance.

[0032] In the above implementation process, the method determines the controller parameters according to the pre-established controlled object model, thereby substituting the controller parameters into the pre-built n-order controller transfer function initial model to build the transfer function of the n-order controller, and simulating the transfer function of the n-order controller to obtain the simulation results. The high-order inertia thermal process system is controlled by the n-order controller to experimentally test the transfer function of the n-order controller and obtain the experimental test results. Among them, the n-order controller transfer function initial model is constructed based on the PI controller sub-model and the lead link sub-model, so as to realize the transformation of the traditional typical thermal system with n first-order inertia links in series into a new system with arbitrarily configurable closed-loop poles. The combination of the PI controller sub-model and the lead link sub-model solves the existing PID control parameter tuning difficulties, the set value tracking ability and the disturbance suppression ability are not ideal, and overcomes the limitations of traditional PID control in complex thermal processes. Compare the current simulation results with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated. Simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the transfer function of the n-order controller corresponding to the difference between the simulation results and the experimental test results being less than the preset difference threshold is determined as the final transfer function of the n-order controller, thereby ensuring that the final transfer function of the n-order controller has the best control performance. The transfer function of the n-order controller obtained by this method is relatively simple and practical in the actual application of parameter tuning, which not only avoids the tuning process from consuming a lot of time, but also improves the control effect of the controller, effectively overcomes the limitations of traditional PID in high-order inertial systems, can obtain better tracking effect and disturbance suppression effect, and parameter tuning is more convenient, which can promote the development of thermal power plants in a more efficient and economical direction.

[0033] Specifically, the n-order controller provided by the method is composed of a PI controller and an (n-1)-order lead link in a positive feedback structure, and achieves a control effect that a PID controller cannot achieve in the control of thermal processes with characteristics such as high-order inertia. Specifically, the n-order controller can transform a typical thermal system with n traditional first-order inertia links in series into a new system with arbitrarily configurable closed-loop poles, which can meet the closed-loop pole configuration of different requirements, thereby making the use of the controller more flexible; in terms of parameter setting, the design of the n-order controller has a very clear goal, and the influence of its three adjustable parameters on the control performance shows a strong regularity; in terms of tracking performance, under the same conditions, it can obtain a better set value tracking effect than PID control; in terms of disturbance suppression, the closed-loop system formed by the n-order controller has a stronger anti-interference ability and can more effectively suppress the influence of external disturbances on system performance.

[0034] In some implementations of this embodiment, the controller parameters include the controller order n; the n-order controller parameter tuning rule includes: when The smaller the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is less than the first preset value, a high-order inertia thermal process system oscillation will occur; when The larger the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is greater than the second preset value, the high-order inertia thermal process system will overshoot; when the controller order n is the same as the order of the controlled object model, it means that the high-order inertia thermal process system has the best tracking effect and anti-disturbance effect; when When the value gradually decreases, based on As the value of the value decreases, the response speed of the high-order inertia thermal process system will gradually increase; among them, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, It is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller.

[0035] Specifically, when The smaller the value, the shorter the system adjustment time and the stronger the anti-interference ability. Too small a value will cause system oscillation; when The larger the value, the shorter the system adjustment time and the stronger the anti-interference ability. Too large a value will also cause a certain overshoot; when the controller order n is the same as the controlled object order, the system tracking effect and anti-disturbance effect are best; when The smaller the value, the faster the system responds and the stronger the anti-interference ability.

[0036] In some implementations of this embodiment, after obtaining the final transfer function of the n-order controller, the method also includes: deploying the final transfer function of the n-order controller to a high-order inertia thermal process system, and detecting the n-order controller in the high-order inertia thermal process system according to a preset monitoring cycle to obtain detection data; and saving the simulation results, experimental test results and detection data corresponding to the n-order controller to a database.

[0037] Specifically, according to the preset monitoring cycle, the performance monitoring and maintenance of the high-order inertia thermal process system is performed regularly to ensure that the n-order controller is working normally. During the entire implementation process, this method timely records all design data, simulation and experimental test data, controller parameter adjustment and optimization process, and system parameter change process of the n-order controller to provide a reference for subsequent adjustment and optimization.

[0038] Example 2 In view of the problems that PID controller parameter tuning is difficult and the set value tracking capability and disturbance suppression capability are not ideal in thermal process control systems with high-order and large inertia characteristics, an embodiment of the present invention provides a transfer function construction method for an n-order controller.

[0039] Figure 2 It is a control structure diagram of a controller provided by an embodiment of the present invention, wherein Gnc(s) is the controller transfer function and Gn(s) is the transfer function of the controlled object. Figure 2 Medium n-order controller for , the accused is the nth-order inertia link, that is .

[0040] Figure 3 It is a structural diagram of an n-order controller provided by an embodiment of the present invention. The derivation process of the n-order controller is as follows: The n-th order controlled object is , using the n-order controller form .Depend on Figure 2 The closed-loop characteristic equation of the control structure is: (1); The open loop transfer function is: (2); The closed-loop transfer function is: (3): Let the integral time be equal to the time constant of the controlled object, that is, ,but (4); (5); (6); According to formula (6), we can know that: (7); For equation (7), when the closed-loop pole is a heavy pole, that is, ,but (8); make , then (9); Therefore, the transfer function of the n-th order controller is (10): make , then the controller has only two parameters kc, Ti, at this time, Gnc(s) is (11); At this time, the closed-loop system transfer function is: (12); therefore, the parameter It can be used to arbitrarily configure the closed-loop poles.

[0041] According to formula (11), we can know (13); Therefore, the n-order controller can be obtained by Figure 3 express.

[0042] In addition, when n=1, (14); This is the proportional-integral (PI) controller.

[0043] When n=2, (15); This is a proportional-integral-derivative (PID) controller. Obviously, the PID control commonly used in industrial process control is a special case of the n-th order controller proposed in this application when n=1 and n=2.

[0044] The embodiment of the present application illustrates the advantages of the n-order controller through two parts: one is to analyze the parameters of the n-order controller and analyze its control characteristics and performance; the other is to compare it with PID control and evaluate their respective control effects.

[0045] In the following simulation, the set value signal adopts a unit step signal, that is, , the step time is 1s; the controlled object is , the amplitude of the added step disturbance is 0.2.

[0046] (1) Comparison of n-order controller and PID control effect: Figure 4 This is a comparison chart of the n-order controller and the controller set value tracking capability provided by an embodiment of the present invention. It can be seen that the n-order controller has a shorter system adjustment time and no overshoot, and has a better set value tracking effect; Figure 5This is a comparison diagram between an n-order controller and a controller control signal provided by an embodiment of the present invention. It can be seen that the control effect of the n-order controller is better than the PID control effect when its control signal is much smaller than the PID control signal. At the same time, the control effect of the n-order controller is also significantly better than the PI control effect when its control signal is close to the PI controller signal. Figure 6 This is a comparison diagram of the disturbance suppression capabilities of an n-order controller and a controller provided in an embodiment of the present invention. It can be seen that the disturbance suppression capability of the n-order controller is stronger.

[0047] (2) Design and analysis of n-order controller: 1. The influence of controller order n on control effect: Figure 7 It is a comparison diagram of control effects under different controller orders provided by an embodiment of the present invention. By analyzing the influence of the controller order on the control effect, it can be known that when the controller order is the same as the controlled object order, the tracking effect and anti-disturbance effect of the system are best.

[0048] 2. The impact of values ​​on control effect: Setting targets for controller parameters: , in simulation The value selection range is deviation value scope. Figure 8 An embodiment of the present invention provides different The control effect comparison chart under the value is analyzed by The influence of the value on the control effect can be seen. The smaller the value, the shorter the system adjustment time and the stronger the anti-interference ability. A value that is too small will cause system oscillation.

[0049] 3. The influence of value on control effect: Fig. 9 An embodiment of the present invention provides different The control effect comparison chart under the value is analyzed by The influence of the value on the control effect can be seen. The smaller the value, the faster the system responds and the stronger the anti-interference ability.

[0050] 4. The impact of values ​​on control effect: Setting targets for controller parameters: , in simulation The value selection range is deviation value scope. Fig.10 An embodiment of the present invention provides different The control effect comparison chart under the value is analyzed by The influence of the value on the control effect can be seen. The larger the value, the shorter the system adjustment time and the stronger the anti-interference ability. However, if the value is too large, it will also cause a certain overshoot.

[0051] Example 3 Fig.12 1 is a block diagram of a transfer function construction system for an n-order controller provided by an embodiment of the present invention. Fig.12 As shown, an embodiment of the present invention provides a transfer function construction system for an n-order controller, comprising: A controller parameter determination module, used for determining controller parameters based on a pre-established controlled object model; A controller transfer function construction module is used to construct the transfer function of the n-order controller based on the controller parameters and the pre-constructed n-order controller transfer function initial model, and simulate and experimentally test the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the n-order controller transfer function initial model is constructed based on the PI controller sub-model and the lead link sub-model; The controller transfer function adjustment and optimization module is used to determine whether the transfer function of the n-order controller needs to be adjusted and optimized based on the difference between the current simulation results and the experimental test results. If the transfer function of the n-order controller needs to be adjusted and optimized, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated, and simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the controller transfer function adjustment and optimization module is repeatedly executed until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, thereby obtaining the final transfer function of the n-order controller.

[0052] Specifically, the system determines the controller parameters according to the pre-established controlled object model, and then substitutes the controller parameters into the pre-built n-order controller transfer function initial model to build the transfer function of the n-order controller, and simulates the transfer function of the n-order controller to obtain simulation results. The high-order inertia thermal process system is controlled by the n-order controller to experimentally test the transfer function of the n-order controller and obtain experimental test results. Among them, the n-order controller transfer function initial model is constructed based on the PI controller sub-model and the lead link sub-model, so as to realize the transformation of the traditional typical thermal system with n first-order inertia links in series into a new system with arbitrarily configurable closed-loop poles. The combination of the PI controller sub-model and the lead link sub-model solves the existing PID control parameter tuning difficulties, the set value tracking ability and the disturbance suppression ability are not ideal, and overcomes the limitations of traditional PID control in complex thermal processes. Compare the current simulation results with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated. Simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the transfer function of the n-order controller corresponding to the difference between the simulation results and the experimental test results being less than the preset difference threshold is determined as the final transfer function of the n-order controller, thereby ensuring that the final transfer function of the n-order controller has the best control performance. The transfer function of the n-order controller obtained by the system is relatively simple and practical in the actual application of parameter tuning, which not only avoids the tuning process from consuming a lot of time, but also improves the control effect of the controller, effectively overcomes the limitations of traditional PID in high-order inertial systems, can obtain better tracking effect and disturbance suppression effect, and parameter tuning is more convenient, which can promote the development of thermal power plants in a more efficient and economical direction.

[0053] The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical scheme of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0055] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including a number of instructions to enable a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0056] In addition, various implementation modes of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed by the embodiments of the present invention.

Claims

1. A method for constructing a transfer function of an n-order controller, characterized in that: include: S110: Determine controller parameters based on a pre-established controlled object model; S120: constructing a transfer function of the n-order controller based on controller parameters and a pre-constructed initial model of the n-order controller transfer function, and performing simulation and experimental tests on the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the initial model of the n-order controller transfer function is constructed based on a PI controller sub-model and a lead link sub-model; S130: Based on the difference between the current simulation results and the experimental test results, determine whether it is necessary to adjust and optimize the transfer function of the n-order controller. If it is necessary to adjust and optimize the transfer function of the n-order controller, adjust the controller parameters, and based on the adjusted controller parameters, update the transfer function of the n-order controller. Simulate and experimentally test the transfer function of the updated n-order controller respectively, and repeat S130 until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, so as to obtain the final transfer function of the n-order controller.

2. The transfer function construction method of the n-th order controller according to claim 1, characterized in that: The establishment rules of the controlled object model include: Carry out mechanism modeling or system identification for high-order inertial thermal process systems to establish a controlled object model; The transfer function of the controlled object model is , is the gain coefficient of the high-order inertia thermal process system, is the time constant of the high-order inertial thermal process system, n is the order of the high-order inertia thermal process system.

3. The method for constructing a transfer function of an n-order controller according to claim 1, characterized in that: The construction rules of the initial model of the n-th order controller transfer function are: The PI controller sub-model and the lead link sub-model are combined in the form of a positive feedback structure to obtain the initial model of the n-order controller transfer function; The initial model of the n-order controller transfer function is: , the leading link sub-model is ;in, , , , is the Laplace operator, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, Determine the order of the leading link, The value of is determined by the order of the controlled object model. is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller, is the closed-loop control system time constant of the PI controller.

4. The method for constructing a transfer function of an n-order controller according to claim 3, characterized in that: The transfer function of the forward channel of the positive feedback structure is n Step-ahead link , the transfer function of the feedback channel of the positive feedback structure is n Inertia link , after combining the transfer function of the forward path and the transfer function of the feedback path, the external controller gain .

5. The method for constructing a transfer function of an n-order controller according to claim 1, characterized in that: Based on the difference between the current simulation result and the experimental test result, it is determined whether the transfer function of the n-order controller needs to be adjusted and optimized. If the transfer function of the n-order controller needs to be adjusted and optimized, the controller parameters are adjusted, including: Compare the current simulation results with the experimental test results. If the difference between the current simulation results and the experimental test results is greater than the preset difference threshold, then n The controller parameters are adjusted by using the parameter tuning rules of the first-order controller; among them, Said n The parameter tuning rules of the first-order controller are obtained based on the controlled object model.

6. The method for constructing a transfer function of an n-order controller according to claim 5, characterized in that: The controller parameters include the controller order n; The n-th order controller parameter tuning rules include: when The smaller the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is less than the first preset value, a high-order inertia thermal process system oscillation will occur; when The larger the value, the shorter the adjustment time of the high-order inertia thermal process system; When the value is greater than the second preset value, a high-order inertia thermal process system overshoot will occur; When the controller order n is the same as the order of the controlled object model, it means that the high-order inertia thermal process system has the best tracking effect and anti-disturbance effect; when When the value gradually decreases, based on As the value of the value decreases, the response speed of the high-order inertia thermal process system will gradually increase; in, is the gain coefficient of the PI controller, is the integral time constant of the PI controller, It is the adjustment coefficient of the time constant of the closed-loop control system of the PI controller.

7. The method for constructing a transfer function of an n-order controller according to claim 1, characterized in that: After obtaining the final transfer function of the n-th order controller, the method further includes: The transfer function of the final n-order controller is deployed to the high-order inertia thermal process system, and the n-order controller in the high-order inertia thermal process system is tested according to a preset monitoring cycle to obtain test data; The simulation results, experimental test results and detection data corresponding to the n-order controller are saved in the database.

8. A transfer function construction system for an n-th order controller, characterized in that: include: A controller parameter determination module, used for determining controller parameters based on a pre-established controlled object model; A controller transfer function construction module is used to construct a transfer function of an n-order controller based on controller parameters and a pre-constructed n-order controller transfer function initial model, and to simulate and experimentally test the transfer function of the n-order controller to obtain simulation results and experimental test results; wherein the n-order controller transfer function initial model is constructed based on a PI controller sub-model and a lead link sub-model; The controller transfer function adjustment and optimization module is used to determine whether the transfer function of the n-order controller needs to be adjusted and optimized based on the difference between the current simulation results and the experimental test results. If the transfer function of the n-order controller needs to be adjusted and optimized, the controller parameters are adjusted, and based on the adjusted controller parameters, the transfer function of the n-order controller is updated, and simulation and experimental tests are performed based on the updated transfer function of the n-order controller, and the controller transfer function adjustment and optimization module is repeatedly executed until the difference between the current simulation results and the experimental test results is less than a preset difference threshold, thereby obtaining the final transfer function of the n-order controller.

9. A machine-readable storage medium having instructions stored thereon, characterized in that: When the instruction is executed by a processor, the processor is configured to execute the transfer function construction method of the n-order controller as claimed in any one of claims 1 to 7.

10. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the transfer function construction method of the n-th order controller according to any one of claims 1 to 7 is implemented.

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