Optimization control method and system of denitration system, controller and computer readable storage medium

Abstract

The invention provides an optimization control method and system for a denitration system, a controller and a computer readable storage medium, and the method comprises the steps: building an order state space model from an ammonia injection control valve to a chimney outlet nitrogen oxide concentration based on the data of the change of the ammonia injection control valve of a thermal power generating unit and the change of the chimney outlet nitrogen oxide concentration; designing a feedforward signal of the denitration control system; designing an input inertia compensation link of the ammonia injection control valve based on the state space model; the output of the input inertia compensation link and the chimney outlet nitrogen oxide concentration are sent into an improved cascade expansion state observer; designing a lead-lag compensation link based on the output of the improved cascade expansion state observer; designing a control law based on the output of the improved cascade expansion state observer, the output of the lead-lag compensation link and a chimney outlet nitrogen oxide concentration set value; and updating the ammonia injection control valve into the sum of the output of the control law and the feedforward control quantity, and adjusting the denitration system according to the updated ammonia injection control valve.

Description

Technical Field

[0001] The present invention relates to the field of optimization control of denitration systems of thermal power plants, and in particular to an optimization control method, system, controller and computer-readable storage medium for a denitration system. Background Art

[0002] NOx emitted by thermal power units accounts for about 21% of the total emissions. Improving the operation level of the denitrification system of coal-fired units is an effective means and important guarantee for reducing NOx emissions. However, the denitrification system faces many external interferences such as inlet nitrogen oxide concentration, load, secondary air volume, start-stop grinding, etc. In addition, the denitrification system is a typical large inertia system with control difficulties such as slow response speed and weak anti-interference ability. With the wide load operation of thermal power units, the stable operation of the denitrification system is faced with greater challenges.

[0003] At present, the control research of denitrification system of thermal power units mainly includes feedforward control, weak model feedback control such as PID, strong model feedback control such as model predictive control, and feedback control based on artificial intelligence. Feedforward control mainly speeds up the response speed of the denitrification system through the inlet nitrogen oxide concentration, and generally needs to be used in combination with feedback control; PID has the advantages of simple structure, stable performance and easy engineering implementation, but it has shortcomings such as slow response speed and weak anti-interference ability when dealing with large inertia processes; robust control also does not rely on accurate mathematical models, but the designed controller is generally a high-order controller, which is difficult to implement in engineering and has strong conservatism. Model predictive control has a satisfactory control effect when the model is accurately known, but the control performance decreases significantly when the model deviates from the design conditions; feedback control based on artificial intelligence has limited practical application value due to difficulties such as computational complexity, difficulty in ensuring convergence and difficulty in engineering implementation. Active disturbance rejection control has strong anti-interference ability and does not rely on accurate mathematical models, and has received widespread attention. In order to solve the problem of active disturbance rejection control in dealing with large inertia processes, Chinese invention patents with application numbers CN201810041569.0 and CN202011125339.6 designed improved schemes for input and output compensation respectively. However, the improved schemes did not improve the extended state observer, which resulted in problems such as the extended state observer being too high in order and limited bandwidth when the compensation order of the observer was low. Summary of the invention

[0004] The purpose of the present invention is to improve the control quality of a denitration system, and to provide an optimization control method, system, controller and computer-readable storage medium for a denitration system.

[0005] In a first aspect, the present invention provides an optimization control method for a denitration system, comprising the following steps:

[0006] 1) Based on the data of the change of ammonia injection valve and the change of nitrogen oxide concentration at the chimney outlet of the thermal power unit, an n-order state space model from the ammonia injection valve u to the nitrogen oxide concentration y at the chimney outlet is established;

[0007] 2) Design the feedforward signal u of the denitrification control system ff ;

[0008] 3) Design the ni-order input inertia compensation link of the ammonia injection valve u based on the n-order state space model, and i∈[1,n];

[0009] 4) Input the output of the inertia compensation link and the chimney outlet nitrogen oxide concentration y are sent to the j-order improved cascade expanded state observer;

[0010] 5) Based on the output z of the improved cascade extended state observer j+1 Design lead-lag compensation link;

[0011] 6) Based on the output z of the improved cascade extended state observer j+1 And the output z of the lead-lag compensation link a,j+1 and chimney outlet nitrogen oxide concentration set value r to design the control law;

[0012] 7) Update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of u = u1 + u ff The denitrification system adjusts the ammonia injection valve according to the updated u to regulate the denitrification system.

[0013] Based on the above, the n-order state space model from the ammonia injection valve u to the chimney outlet nitrogen oxide concentration y is established as follows:

[0014]

[0015] In the formula, is the state variable of the denitrification system,

[0016] is the state matrix of the denitrification system,

[0017] is the input matrix of the denitrification system, is the output matrix of the denitrification system, u is the ammonia injection valve, y is the nitrogen oxide concentration at the chimney outlet; n is the state space model order, n∈(1,10 10 ] and is an integer; T is the parameter of the state space model, and T∈(0,10 10 ]; b is the gain of the state space model, b∈[-10 10 ,0).

[0018] Based on the above, the feedforward signal u of the designed denitrification control system ff It contains the following parts:

[0019]

[0020] In the formula, u ffi is the i-th feedforward action, g i is the weight of the i-th feedforward action;

[0021] u ff1 Feedforwarding the inlet nitrogen oxide concentration of the selective catalytic reduction device by using proportional-derivative control with the inlet nitrogen oxide concentration as input or calculating through an interpolation function;

[0022] u ff2 For the outlet concentration feedforward of the selective catalytic reduction device, a proportional-derivative control with the outlet nitrogen oxide concentration as input is adopted or calculation is performed through an interpolation function;

[0023] u ff3 To eliminate the feedforward of the deviation of the nitrogen oxide concentration at the outlets of the selective catalytic reduction device on both sides, a proportional-integral control with the nitrogen oxide concentration difference on both sides as input is adopted or calculation is performed through an interpolation function;

[0024] u ff4 For coal mill start and stop feedforward, differential control with coal mill start and stop signal as input or calculation through interpolation function is adopted;

[0025] u ff5 For high feedforward of ammonia slip, proportional-integral control with ammonia slip concentration as input or calculation through interpolation function is adopted;

[0026] u ff6 For load feedforward control, proportional-derivative control with load as input is adopted or calculation is performed through interpolation function.

[0027] Based on the above, the expression of the designed input inertia compensation link is:

[0028]

[0029] In the formula, is the state variable of the input inertia compensation link;

[0030] is the state matrix of the input inertia compensation link;

[0031] It is the input matrix of the inertia compensation link.

[0032] Based on the above, the improved cascade extended state observer is designed as follows:

[0033] If j = 1, the improved cascade extended state observer is:

[0034]

[0035] If j ≥ 2, the improved cascade extended state observer is:

[0036]

[0037] In the formula, ξ1, ξ i and j are intermediate variables, z1, z i and z j To improve the output of the cascade expanded state observer, it is also an estimate of the state of the denitrification system; l1, l i and l j is to improve the gain of the cascade extended state observer, is the parameter that needs to be adjusted; b0 is the estimated value of the gain b of the state space model, is the parameter that needs to be adjusted.

[0038] Based on the above, the designed lead-lag compensation link is:

[0039]

[0040] Where T m is the time constant of the lead-lag compensation link, λ is the coefficient of the lead-lag compensation link, z a,j+1 is the output of the lead-lag compensation link; T m and λ are the parameters that need to be adjusted.

[0041] Based on the above, the expression of the designed control law is as follows:

[0042]

[0043] Where k2, k i and k j is the gain of the control law, is the parameter that needs to be adjusted; u1 is the output of the control law.

[0044] In a second aspect, the present invention provides an optimization control system for a denitration system, comprising:

[0045] The state space model module presets an n-order state space model; the n-order state space model is a state space model from the ammonia injection control valve u to the chimney outlet nitrogen oxide concentration y established based on the data of the change of the ammonia injection control valve of the thermal power unit and the change of the nitrogen oxide concentration at the chimney outlet;

[0046] Feedforward signal u ff Module, used to provide feedforward signal u for denitrification control system ff ;

[0047] An input inertia compensation link module, the input end of which is connected to the ammonia injection regulating valve u; the input inertia compensation link is an ni-order input inertia compensation link based on an n-order state space model of the ammonia injection regulating valve u, and i∈[1,n];

[0048] The extended state observer module has its input connected to the output of the input inertia compensation link. and chimney outlet nitrogen oxide concentration y; the extended state observer is based on the output of the input inertia compensation link and the j-order improved cascade expanded state observer designed based on the chimney outlet nitrogen oxide concentration y;

[0049] Lead-lag compensation module, the input end is connected to the output z of the extended state observer module j+1 ; The lead-lag compensation link is based on the output z of the improved cascade extended state observer j+1 designed;

[0050] Control law module, the input end is connected to the output z of the extended state observer module j+1 , the output of the lead-lag compensation module z a,j+1 and chimney outlet nitrogen oxide concentration set value r; the control law is based on the output z of the improved cascade extended state observer j+1 And the output z of the lead-lag compensation link a,j+1 and chimney outlet nitrogen oxide concentration set value r;

[0051] The control module connects the ammonia injection valve u, the output u1 of the control law module and the feedforward control quantity u ff ; The control method is to update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of u = u1 + u ff , and adjust the ammonia injection valve according to the updated u to regulate the denitrification system.

[0052] In a third aspect, the present invention provides a controller for a denitration system, comprising:

[0053] one or more processors;

[0054] a memory for storing one or more programs,

[0055] When the one or more programs are executed by the one or more processors, the one or more processors perform the steps of the optimization control method of the denitration system.

[0056] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the optimization control method for the denitrification system.

[0057] Compared with the prior art, the present invention has outstanding substantive features and significant progress, specifically:

[0058] 1. Aiming at the control difficulties of the main steam pressure system of the thermal power unit, the present invention designs an input inertia compensation link based on the state space model of the main steam pressure system, and designs an improved extended state observer, so that the extended state observer becomes a cascade form of low-order extended state observers, which can effectively avoid the problems of too high order and limited bandwidth of the extended state observer when the compensation order of the observer is low.

[0059] 2. The present invention designs an input inertia compensation link so that the control method of the denitrification system has the advantages of resisting amplitude and rate saturation.

[0060] 3. The improvement of the input inertia compensation link proposed in the present invention can achieve a satisfactory control effect when b0 deviates greatly from the gain b of the state space model. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a diagram of the implementation steps of the method of the present invention.

[0062] Figure 2 The control principle block diagram of the method of the present invention.

[0063] Figure 3 The figure shows the control effects of the method of the present invention and the comparative method in actual units. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0065] Example 1

[0066] This embodiment proposes an optimization control method for a denitration system, the process is as follows Figure 1 As shown, the control principle is as follows Figure 2 As shown, the following steps are included:

[0067] 101) Based on the data of the change of ammonia injection valve and the change of nitrogen oxide concentration at the chimney outlet of the thermal power unit, an n-order state space model from the ammonia injection valve u to the nitrogen oxide concentration y at the chimney outlet is established:

[0068]

[0069] In the formula, is the state variable of the denitrification system,

[0070] is the state matrix of the denitrification system,

[0071] is the input matrix of the denitrification system, is the output matrix of the denitrification system, u is the ammonia injection valve, y is the nitrogen oxide concentration at the chimney outlet; n is the state space model order, n∈(1,10 10 ] and is an integer; T is the parameter of the state space model, and T∈(0,10 10 ]; b is the gain of the state space model, b∈[-10 10 ,0).

[0072] 102) Design the feedforward signal u of the denitrification control system ff ,u ff It contains the following parts:

[0073]

[0074] In the formula, u ffi is the i-th feedforward action, g i is the weight of the i-th feedforward action;

[0075] u ff1 Feedforwarding the inlet nitrogen oxide concentration of the selective catalytic reduction device by using proportional-derivative control with the inlet nitrogen oxide concentration as input or calculating through an interpolation function;

[0076] u ff2 For the outlet concentration feedforward of the selective catalytic reduction device, a proportional-derivative control with the outlet nitrogen oxide concentration as input is adopted or calculation is performed through an interpolation function;

[0077] u ff3 To eliminate the feedforward of the deviation of the nitrogen oxide concentration at the outlets of the selective catalytic reduction device on both sides, a proportional-integral control with the nitrogen oxide concentration difference on both sides as input is adopted or calculation is performed through an interpolation function;

[0078] u ff4 For coal mill start and stop feedforward, differential control with coal mill start and stop signal as input or calculation through interpolation function is adopted;

[0079] u ff5 For high feedforward of ammonia slip, proportional-integral control with ammonia slip concentration as input or calculation through interpolation function is adopted;

[0080] u ff6 For load feedforward control, proportional-derivative control with load as input is adopted or calculation is performed through interpolation function.

[0081] 103) Design an input inertia compensation link of the ammonia injection valve u based on an n-order state space model of the ni order, and i∈[1,n];

[0082] The expression of the designed input inertia compensation link is:

[0083]

[0084] In the formula, is the state variable of the input inertia compensation link;

[0085] is the state matrix of the input inertia compensation link;

[0086] It is the input matrix of the inertia compensation link.

[0087] 104) The output of the inertia compensation link input in step 103) is and the chimney outlet nitrogen oxide concentration y are sent to the j-order improved cascade expanded state observer;

[0088] The improved cascade extended state observer is designed as follows:

[0089] If j = 1, the improved cascade extended state observer is:

[0090]

[0091] If j ≥ 2, the improved cascade extended state observer is:

[0092]

[0093] In the formula, ξ1, ξ i and j are intermediate variables, z1, z i and z j To improve the output of the cascade expanded state observer, it is also an estimate of the state of the denitrification system; l1, l i and l j is to improve the gain of the cascade extended state observer, is the parameter that needs to be adjusted; b0 is the estimated value of the gain b of the state space model, is the parameter that needs to be adjusted.

[0094] It should be noted that the parameters that need to be adjusted (hereinafter the same) refer to the parameters that are designed. The specific values ​​to be used can be determined by a variety of adjustment methods, wherein the adjustment methods can adopt existing methods, which are not specifically discussed in the present invention. The parameters that need to be adjusted are given as given values ​​and are directly given when the present invention is specifically implemented.

[0095] 105) Based on the output z of the improved cascade extended state observer in step 104)j+1 Design lead-lag compensation link;

[0096] The designed lead-lag compensation link is:

[0097]

[0098] Where T m is the time constant of the lead-lag compensation link, λ is the coefficient of the lead-lag compensation link, z a,j+1 is the output of the lead-lag compensation link; T m and λ are the parameters that need to be adjusted.

[0099] 106) Based on the output z of the improved cascade extended state observer in step 104) j+1 and the output z of the lead-lag compensation link in step 105) a,j+1 and chimney outlet nitrogen oxide concentration set value r to design the control law;

[0100] The expression of the designed control law is as follows:

[0101]

[0102] Where k2, k i and k j is the gain of the control law, is the parameter that needs to be adjusted; u1 is the output of the control law.

[0103] 107) Update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of , that is:

[0104] u=u1+u ff (8)

[0105] The denitrification system adjusts the ammonia injection valve according to u obtained by formula (8) to regulate the denitrification system.

[0106] Comparative experiment

[0107] In order to analyze the effectiveness of the method of this embodiment, the method of this embodiment is applied to the actual unit. After the control logic of the original distributed control system (comparison method) runs for 10,000 seconds, it is switched to the method of this embodiment. It can be obtained Figure 3 The running results are shown. Figure 3 (a) is the unit load. It can be seen from the figure that the fluctuation range of the unit load before and after the switch is relatively close; Figure 3 (b) The thick solid line is the nitrogen oxide concentration at the chimney outlet, and the thin solid line is the set value of the nitrogen oxide concentration at the chimney outlet. It can be seen from the figure that the fluctuation range of the nitrogen oxide concentration at the chimney outlet is significantly reduced after the method of the present invention is put into use; Figure 3(c) shows the changes in the ammonia injection valves on the left and right sides.

[0108] In order to better quantitatively measure the control effect of the denitrification system before and after the implementation of the method of this embodiment, the fluctuation range and the absolute value integral of the error before and after the implementation of the method of this embodiment are calculated. The fluctuation range of the comparative method is [-37.45, 27.12] mg / m 3 The fluctuation range of the method in this embodiment is [-21.11,9.84]mg / m 3 The absolute value integral of the error of the comparison method is 2.82×10 5 The absolute value integral of the error of the method in this embodiment is 1.54×10 5 Therefore, after the method of this embodiment is put into use, the fluctuation range of the nitrogen oxide concentration at the chimney outlet of the denitrification system is effectively reduced, which verifies that the method of this embodiment improves the control quality of the denitrification system.

[0109] Example 2

[0110] Based on the same inventive concept, the embodiment of the present application also provides an optimization control system for a denitration system. The implementation scheme for solving the problem provided by the optimization control system for the denitration system is similar to the implementation scheme recorded in the method of Example 1, so the specific limitations in the embodiments of the optimization control system for one or more denitration systems provided below can refer to the limitations on the method in Example 1, and will not be repeated here.

[0111] In an exemplary embodiment, an optimization control system of a denitration system is provided, comprising:

[0112] The state space model module presets an n-order state space model; the n-order state space model is a state space model from the ammonia injection control valve u to the chimney outlet nitrogen oxide concentration y established based on the data of the change of the ammonia injection control valve of the thermal power unit and the change of the nitrogen oxide concentration at the chimney outlet;

[0113] Feedforward signal u ff Module, used to provide feedforward signal u for denitrification control system ff ;

[0114] An input inertia compensation link module, the input end of which is connected to the ammonia injection regulating valve u; the input inertia compensation link is an ni-order input inertia compensation link based on an n-order state space model of the ammonia injection regulating valve u, and i∈[1,n];

[0115] The extended state observer module has its input connected to the output of the input inertia compensation link. and chimney outlet nitrogen oxide concentration y; the extended state observer is based on the output of the input inertia compensation link and the j-order improved cascade expanded state observer designed based on the chimney outlet nitrogen oxide concentration y;

[0116] Lead-lag compensation module, the input end is connected to the output z of the extended state observer module j+1 ; The lead-lag compensation link is based on the output z of the improved cascade extended state observer j+1 designed;

[0117] Control law module, the input end is connected to the output z of the extended state observer module j+1 , the output of the lead-lag compensation module z a,j+1 and chimney outlet nitrogen oxide concentration set value r; the control law is based on the output z of the improved cascade extended state observer j+1 And the output z of the lead-lag compensation link a,j+1 and chimney outlet nitrogen oxide concentration set value r;

[0118] The control module connects the ammonia injection valve u, the output u1 of the control law module and the feedforward control quantity u ff ; The control method is to update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of u = u1 + u ff , and adjust the ammonia injection valve according to the updated u to regulate the denitrification system.

[0119] Example 3

[0120] Each module in the above system can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module above.

[0121] In an exemplary embodiment, a controller of a denitration system is provided, and the computer device may be a terminal. The computer device further includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, the memory, and the input / output interface are connected via a system bus, and the communication interface, the display unit, and the input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, the steps of the optimization control method of the denitration system are implemented. The display unit of the computer device is used to form a visually visible picture, which may be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0122] Those skilled in the art will appreciate that the structure of the above-mentioned computer device is only a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components, or combine certain components, or have a different arrangement of components.

[0123] In an exemplary embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the optimization control method of the denitration system are implemented.

[0124] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0125] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An optimization control method for a denitration system, characterized in that: The following steps are involved: 1) Based on the data of the change of ammonia injection valve and the change of nitrogen oxide concentration at the chimney outlet of the thermal power unit, an n-order state space model from the ammonia injection valve u to the nitrogen oxide concentration y at the chimney outlet is established; 2) Design the feedforward signal u of the denitrification control system ff ; 3) Design the ni-order input inertia compensation link of the ammonia injection valve u based on the n-order state space model, and i∈[1,n]; 4) Input the output of the inertia compensation link and the chimney outlet nitrogen oxide concentration y are sent to the j-order improved cascade expanded state observer; 5) Based on the output z of the improved cascade extended state observer j+1 Design lead-lag compensation link; 6) Based on the output z of the improved cascade extended state observer j+1 And the output z of the lead-lag compensation link a，j+1 and chimney outlet nitrogen oxide concentration set value r to design the control law; 7) Update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of u = u1 + u ff The denitrification system adjusts the ammonia injection valve according to the updated u to regulate the denitrification system.

2. The optimization control method of the denitration system according to claim 1, characterized in that: The n-order state space model from the ammonia injection valve u to the chimney outlet nitrogen oxide concentration y is established as follows: In the formula, is the state variable of the denitrification system, is the state matrix of the denitrification system, is the input matrix of the denitrification system, is the output matrix of the denitrification system, u is the ammonia injection valve, y is the nitrogen oxide concentration at the chimney outlet; n is the order of the state space model, and n∈(1, 10 10 ] and is an integer; T is the parameter of the state space model, and T∈(0, 10 10 ]; b is the gain of the state space model, b∈[-10 10 , 0).

3. The optimization control method of the denitration system according to claim 2, characterized in that: The feedforward signal u of the designed denitrification control system ff It contains the following parts: In the formula, u ffi is the i-th feedforward action, g i is the weight of the i-th feedforward action; u ff1 Feedforwarding the inlet nitrogen oxide concentration of the selective catalytic reduction device by using proportional-derivative control with the inlet nitrogen oxide concentration as input or calculating through an interpolation function; u ff2 For the outlet concentration feedforward of the selective catalytic reduction device, a proportional-derivative control with the outlet nitrogen oxide concentration as input is adopted or calculation is performed through an interpolation function; u ff3 To eliminate the feedforward of the deviation of the nitrogen oxide concentration at the outlets of the selective catalytic reduction device on both sides, a proportional-integral control with the nitrogen oxide concentration difference on both sides as input is adopted or calculation is performed through an interpolation function; u ff4 For coal mill start and stop feedforward, differential control with coal mill start and stop signal as input or calculation through interpolation function is adopted; u ff5 For high feedforward of ammonia slip, proportional-integral control with ammonia slip concentration as input or calculation through interpolation function is adopted; u ff6 For load feedforward control, proportional-derivative control with load as input is adopted or calculation is performed through interpolation function.

4. The optimization control method of the denitration system according to claim 3, characterized in that: The expression of the designed input inertia compensation link is: In the formula, is the state variable of the input inertia compensation link; is the state matrix of the input inertia compensation link; It is the input matrix of the inertia compensation link.

5. The optimization control method of the denitration system according to claim 4, characterized in that: The improved cascade extended state observer is designed as follows: If j = 1, the improved cascade extended state observer is: If j ≥ 2, the improved cascade extended state observer is: In the formula, ξ1, ξ i and j are intermediate variables, z1, z i and z j To improve the output of the cascade expanded state observer, it is also an estimate of the state of the denitrification system; l1, l i and l j is to improve the gain of the cascade extended state observer, is the parameter that needs to be adjusted; b0 is the estimated value of the gain b of the state space model, is the parameter that needs to be adjusted.

6. The optimization control method of the denitration system according to claim 5, characterized in that: The designed lead-lag compensation link is: Where T m is the time constant of the lead-lag compensation link, λ is the coefficient of the lead-lag compensation link, z a，j+1 is the output of the lead-lag compensation link; T m and λ are the parameters that need to be adjusted.

7. The optimization control method of the denitration system according to claim 6, characterized in that: The expression of the designed control law is as follows: Where k2, k i and k j is the gain of the control law, is the parameter that needs to be adjusted; u1 is the output of the control law.

8. An optimization control system for a denitration system, characterized in that: include: The state space model module presets an n-order state space model; the n-order state space model is a state space model from the ammonia injection control valve u to the chimney outlet nitrogen oxide concentration y established based on the data of the change of the ammonia injection control valve of the thermal power unit and the change of the nitrogen oxide concentration at the chimney outlet; Feedforward signal u ff Module, used to provide feedforward signal u for denitrification control system ff ; An input inertia compensation link module, the input end of which is connected to the ammonia injection regulating valve u; the input inertia compensation link is an ni-order input inertia compensation link based on an n-order state space model of the ammonia injection regulating valve u, and i∈[1, n]; The extended state observer module has its input connected to the output of the input inertia compensation link. and chimney outlet nitrogen oxide concentration y; The extended state observer is based on the output of the input inertia compensation link and the j-order improved cascade expanded state observer designed based on the chimney outlet nitrogen oxide concentration y; Lead-lag compensation module, the input end is connected to the output z of the extended state observer module j+1 ; The lead-lag compensation link is based on the output z of the improved cascade extended state observer j+1 designed; Control law module, the input end is connected to the output z of the extended state observer module j+1 , the output of the lead-lag compensation module z a，j+1 and chimney outlet nitrogen oxide concentration set value r; the control law is based on the output z of the improved cascade extended state observer j+1 And the output z of the lead-lag compensation link a，j+1 and chimney outlet nitrogen oxide concentration set value r; The control module connects the ammonia injection valve u, the output u1 of the control law module and the feedforward control quantity u ff ; The control method is to update the ammonia injection control valve u to the output u1 of the control law and the feedforward control quantity u ff The sum of u = u1 + u ff , and adjust the ammonia injection valve according to the updated u to regulate the denitrification system.

9. A controller for a denitration system, characterized in that: include: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors execute the steps of the optimization control method for the denitration system according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the program is executed by a processor, the steps of the optimization control method of the denitration system as described in any one of claims 1 to 7 are implemented.

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