CN113110030B - CO (carbon monoxide)2Trapped DMC-PID cascading system and control method thereof - Google Patents
CO (carbon monoxide)2Trapped DMC-PID cascading system and control method thereof Download PDFInfo
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B11/00—Automatic controllers
- G05B11/01—Automatic controllers electric
- G05B11/36—Automatic controllers electric with provision for obtaining particular characteristics, e.g. proportional, integral, differential
- G05B11/42—Automatic controllers electric with provision for obtaining particular characteristics, e.g. proportional, integral, differential for obtaining a characteristic which is both proportional and time-dependent, e.g. P.I., P.I.D.
Abstract
The invention discloses a CO2Trapped DMC-PID cascading systems and methods for controlling the same. The DMC-PID cascade control strategy provided by the invention selects a set value CO2The content is the input value of the DMC controller, the output value of the DMC controller is the input value of the PID controller, the PID controller eliminates disturbance variable flue gas flow, and the single-loop PID controller forms an inner loop module; the DMC controller controls the system as a whole. The system not only keeps the excellent performance of the two controllers, but also has the structural characteristics of a cascade system, and completes the control of large delay and strong interference of a controlled object, thereby further improving CO2The capture system has adaptability and flexibility to variable load operation of the thermal power station.
Description
Technical Field
The invention relates to the technical field of control of coal chemical processes, in particular to a post-combustion CO based on MEA (membrane electrode assembly)2DMC-PID cascade predictive control method for trapping process, in particular to CO2Trapped DMC-PID cascading systems and methods for controlling the same.
Background
With carbon dioxide (CO)2) Extreme climate change and sea level rise due to dominant greenhouse gas emissions have become the most serious problems facing mankind in this century. Combustion of fossil fuels, especially coal, as the main source of electricity supply to CO 2The largest fixed source of emissions, and this trend has not changed in recent years. The Carbon Capture and Sequestration (CCS) technology is recognized by various authorities at home and abroad to realize large-scale CO2The most direct and effective means for emission reduction is to transport and store the captured carbon dioxide in a supercritical state for a long time in deep-sea geological wells or ocean wells.
Of the various carbon dioxide capture processes today, post combustion carbon dioxide capture (PCC) based on chemical absorption of ethanolamine solvents (MEA) is considered the most mature viable and promising process because it is less costly and can be easily retrofitted to existing power plants.
As shown in fig. 4, the furnace gas desulfurized in the flue gas cooler enters the absorption tower after being pressurized by the fan,and the gas and the lean solution MEA solution flowing into the tower top are subjected to chemical reaction to remove CO in the furnace gas2Absorption of CO2The rich solution flows out from the bottom of the absorption tower, exchanges heat through a lean and rich solution heat exchanger, is pressurized by a rich solution pump and then is heated to enter a stripping tower, and the rich solution is contacted with steam in a reboiler to generate CO2Desorption effect, desorption of CO2Purifying to obtain high-pressure CO2A gas. To ensure stable operation of the system, water is replenished in the mixer to ensure system balance. The chemical equilibrium reactions involved in this model are shown in formulas (1) - (7):
The kinetic reversible reactions involved can be expressed as:
of primary importance for the entire PCC process is CO2Improvement and achievement of trapping rateAt present, the tracking is fast, but the tracking is influenced by lean solution flow and flue gas flow from a coal power plant, 90% of control strategies adopted by the current thermal power plant are traditional control schemes based on PI and PID control, but the control algorithm cannot solve a multivariable coupling control object, and then the object has the phenomena of large inertia, large lag and strong interference aiming at a reboiler, a condenser and a lean and rich solution heat exchange process in the whole process. Therefore, it is necessary to provide a control method to eliminate the hysteretic interference.
Disclosure of Invention
An object of the present invention is to provide a CO2A trapped DMC-PID cascade system; another object of the present invention is to provide a CO2Trapped DMC-PID cascade system control method. The method solves the problem of CO after combustion2In the capture process, the large inertia and large lag caused by the heat exchange process of a reboiler, a condenser and the lean and rich liquid and the sudden random interference caused by the suppression of the flue gas flow are caused, so that CO is generated2The trapping rate is greatly improved; the method not only keeps the excellent performance of the two controllers, but also has the structural characteristics of a cascade system, and completes the control of large delay and strong interference of the controlled object, thereby further improving CO 2And the capture system has adaptability and flexibility to the variable-load operation of the thermal power station.
In order to achieve the purpose, the invention provides CO2Captured DMC-PID cascading system, including CO2Capture control module and CO2A capture absorption module, the CO2The trapping control module is arranged on the CO2The front end of the trapping and absorbing module; the CO is2The trapping control module mainly comprises an outer ring module and an inner ring module; the outer ring module is connected with the inner ring module in series; the outer ring module mainly consists of a DMC controller, and the inner ring module mainly consists of a PID controller; the DMC controller is sequentially connected with a PID controller and CO2A trapping and absorbing module; the CO is2End-mounted CO of capture absorption module2Content sensor, the CO2The content sensor is connected with the DMC controller, and the CO is2The starting end of the trapping and absorbing module is introduced into the device after combustion through a flue gas pipelineThe flue gas flow sensor is arranged on the flue gas pipeline, the flue gas flow sensor detects the flue gas flow of the flue gas of the coal power plant, and the flue gas flow sensor is connected with the PID controller.
The CO2 capturing and absorbing module mainly comprises an absorbing tower and a stripping tower which are connected with each other.
Said one kind of CO 2The trapped DMC-PID cascade system control method comprises the following implementation steps:
(1) by post-combustion CO2The trapping process is a controlled object, the lean liquid flow is used as a system input quantity (an operation variable), the flue gas flow is used as a disturbance quantity, and CO2The method comprises the steps that firstly, a PCC process model is established in Aspen Plus, then an open-loop test is carried out on the PCC process model, the method is that the model is firstly subjected to steady-state simulation in Aspen Plus, pressure is set to be a driving type, then the model is led out to Aspen Dynamics for dynamic simulation, and then a series of step response tests are carried out on a controlled system according to actual industrial reality constraints of operation variables and disturbance variables and given values of the controlled variables, and the specific operation is as follows: firstly, performing step response test on one of the operation variables, setting other variables to be unchanged, and obtaining the dynamic response change of the controlled variable, so as to analyze the influence of each operation variable on the controlled variable and obtain related response data;
(2) then, model identification of the system is carried out based on a subspace identification method, and the method is characterized in that a parameter matrix of an estimated system model is extracted from a row subspace or a column subspace of a specific Hankel matrix by using input and output data of the system; the state space model of the system can be identified directly by inputting and outputting data, the calculation efficiency is high, and the identification order is easy to select;
The subspace identification algorithm may be divided into two steps:
the method comprises the steps of firstly, constructing a data Hankel matrix and an extended input and output matrix equation, and acquiring a generalized observability matrix gamma of a system through orthogonal projection, linear algebraic tool QR decomposition, singular value decomposition and other methodsfOr estimation of a sequence of states XfTo obtain the phaseA corresponding subspace;
secondly, determining a transfer function model of the system by a least square method and the like according to the obtained generalized observability matrix or state sequence estimation, wherein the set input variable of the DMC controller is CO2The set value of the content is calculated by the DMC controller to obtain the input value of the corresponding PID controller, and then the boundary value and the preset value of the DMC controller are adjusted in the industrial range of the operating variable and the controlled variable to obtain a DMC-PID cascade control system, thereby obtaining CO2The collection rate.
The outer ring module is a constant value system, and the inner ring module is a follow-up system.
Said one kind of CO2Control method for trapped DMC-PID cascade system, setting input variable of DMC controller as outlet CO2And (3) setting the content, taking an output signal as a set value of a PID controller, taking the inner ring flue gas flow as interference, monitoring the inner feedback as flue gas flow, detecting the outer ring flue gas content, and then adjusting a boundary value and a preset value of the DMC controller within the industrial range of an operating variable and a controlled variable to obtain a DMC-PID cascade control structure.
In the control method, the set value of the DMC controller is CO2And (4) content, the PID controller resists and eliminates high-frequency random interference brought by flue gas flow, and the DMC controller completes large-inertia large-lag control by a generalized object.
The method is based on post-combustion CO of MEA2And (4) trapping.
Said one CO2The control method of the trapped DMC-PID cascade system comprises the following two steps:
in the first part, the smoke flow detected by a smoke flow sensor is quickly stabilized by adopting a conventional PID controller algorithm;
second part, for the control of the CO and the PID controller2The method comprises the following steps of designing a DMC controller by a generalized control object formed by a trapping process:
step 1: setting k to be 1, setting the sampling time t to be 2s, setting the modeling time domain N to be 1200, setting the prediction time domain P to be 30, and controlling the time domain M to be 10 to satisfy that M is less than or equal to N and less than or equal to P;
step 2: initializing CO2Collecting process system parameters, v (1) w (1) e1(1) When the value is equal to 0, loop parameters of an inner loop module PID controller; y (1) ═ u (1) ═ e (1) ═ 0, the DMC controller loop parameter of the outer loop module;
step 3: the construction matrix A is a dynamic matrix and consists of a step response coefficient aiA constituent P M matrix;
step 4: according to the formula
Calculating v (1);
step 5: calculating an output error e (1) from the formula e (k) ═ u (k) — p (k);
Step 6: according to the formula
Calculating an outer ring module DMC controller increment delta u (k),. ang., delta u (k + M-1);
step 7: setting a secondary performance index at the moment k:
step 8: calculating to obtain an inner ring module PID controller rule u (1) according to a formula u (k) ═ u (k-1) + delta u (k);
step 9: according to the formula
Calculating to obtain the PID controller rule of the inner ring module, and if v (k) is more than or equal to 10, v (k) is more than 10; if v (k) ≦ -10, v (k) ═ 10;
step 10: according to the formula e1(k)＝w(k)-p1(k) Calculating to obtain the error e of the inner ring module PID controller1(1)；
Step 11: setting k to k +1, returning to step 4;
and at the moment k, calculating an output error e (k) of the current moment by using rolling prediction optimization, and simultaneously calculating a control increment delta u (k) of the current moment to the moment k +1 to obtain a new output error e (k +1) and a new control increment delta u (k +1), wherein the control algorithm is repeatedly carried out on line by combining the rolling optimization mode of feedback correction.
The invention relates to a CO2The trapped DMC-PID cascade system has the advantages that: the method solves the problem of CO after combustion2In the capture process, the large inertia and large lag caused by the heat exchange process of a reboiler, a condenser and the lean and rich liquid and the sudden random interference caused by the suppression of the flue gas flow are caused, so that CO is generated2The trapping rate is greatly improved; the method not only keeps the excellent performance of the two controllers, but also has the structural characteristics of a cascade system, and completes the control of large delay and strong interference of the controlled object, thereby further improving CO 2And the capture system has adaptability and flexibility to the variable-load operation of the thermal power station.
Drawings
FIG. 1 shows CO after combustion2A structural block diagram of a DMC-PID cascade control method of a trapping process;
FIG. 2 shows the CO under the condition of a given slope and having Gaussian white noise interference2DMC-PID cascade control simulation in the trapping process, wherein dotted lines are DMC-PID cascade control, point-cross line PID-PID cascade control and point-dotted line DMC control, and are simulation comparison graphs of smoke flow dynamic control effects under a step set value (the set value is a straight line);
FIG. 3 shows the CO at a given step signal according to the present invention2DMC-PID cascade control simulation of trapping rate, wherein a dotted line is DMC-PID cascade control, a dot transverse line is PID-PID cascade control, and a dot dotted line is DMC control under a slope set value CO2A simulation comparison graph (the set value is a straight line) of the trapping rate dynamic control effect;
FIG. 4 shows CO of a large coal-fired power plant of the present invention2The trapping system is a schematic flow chart.
Detailed Description
Example 1
As shown in FIGS. 1-4, a CO according to the present invention2Captured DMC-PID cascade system comprising CO2Capture control module and CO2A capture absorption module, the CO2The trapping control module is arranged on the CO2The front end of the trapping and absorbing module; the CO is2Catching centralized controlThe manufacturing module mainly comprises an outer ring module and an inner ring module; the outer ring module is connected with the inner ring module in series; the outer ring module mainly consists of a DMC controller, and the inner ring module mainly consists of a PID controller; the DMC controller is sequentially connected with a PID controller and CO 2A trapping and absorbing module; said CO2End-mounted CO of capture absorption module2Content sensor, said CO2The content sensor is connected with the DMC controller, and the CO is2The initiating terminal of entrapment absorption module lets in the coal power plant flue gas after the burning through the flue gas pipeline, install flue gas flow sensor on the flue gas pipeline, flue gas flow sensor detects the flue gas flow of coal power plant flue gas, flue gas flow sensor is connected with the PID controller.
The CO2 capturing and absorbing module mainly comprises an absorbing tower and a stripping tower which are connected with each other.
Said one kind of CO2The control method of the trapped DMC-PID cascade system comprises the following implementation steps:
(1) with post-combustion CO2The trapping process is a controlled object, the lean solution flow is used as an operation variable, the flue gas flow is used as an interference amount, and CO2The trapping rate is used as a controlled variable;
firstly, establishing a PCC process model in Aspen Plus, then carrying out open-loop test on the PCC process model, wherein the method comprises the steps of enabling the model to be subjected to steady-state simulation in Aspen Plus, setting pressure as a driving type, then leading out the pressure to Aspen Dynamics for dynamic simulation, and then carrying out a series of step response tests on a controlled system according to actual industrial practical constraints of operation variables and interference and given values of controlled variables, wherein the specific operations are as follows: firstly, performing step response test on one of the operation variables, setting other variables to be unchanged, and obtaining the dynamic response change of the controlled variable, so as to analyze the influence of each operation variable on the controlled variable and obtain related response data;
(2) Then, identifying the model of the system based on a subspace identification method, wherein the method is characterized in that the input and output data of the system are utilized to extract and estimate a parameter matrix of the system model from a row subspace or a column subspace of a specific Hankel matrix, and the state space model of the system is identified directly according to the input and output data, so that the calculation efficiency is high, and the identification order is easy to select;
the subspace identification algorithm may be divided into two steps:
the method comprises the steps of firstly, constructing a data Hankel matrix and an extended input and output matrix equation, and acquiring a generalized observability matrix gamma of a system through orthogonal projection, linear algebra tool QR decomposition, singular value decomposition and other methodsfOr estimation of a sequence of states XfObtaining the corresponding subspace;
secondly, determining a transfer function model of the system by a least square method and the like according to the obtained generalized observability matrix or state sequence estimation, wherein the set input variable of the DMC controller is CO2The content set value is calculated by the DMC controller to obtain the input value of the corresponding PID controller, and then the boundary value and the preset value of the DMC controller are adjusted in the industrial range of the operation variable and the controlled variable to obtain a DMC-PID cascade control system, thereby obtaining CO 2The collection rate.
The outer ring module is a constant value system, and the inner ring module is a follow-up system.
Said one kind of CO2Control method for trapped DMC-PID cascade system, setting input variable of DMC controller as outlet CO2And (3) setting the content, taking an output signal as a set value of a PID controller, taking the inner ring flue gas flow as interference, monitoring the inner feedback as flue gas flow, detecting the outer ring flue gas content, and then adjusting a boundary value and a preset value of the DMC controller within the industrial range of an operating variable and a controlled variable to obtain a DMC-PID cascade control structure.
In the control method, the set value of a DMC controller is CO2And (4) content, the PID controller resists and eliminates high-frequency random interference brought by flue gas flow, and the DMC controller completes large-inertia large-lag control by a generalized object.
The method is based on post-combustion CO of MEA2And (4) trapping.
Said one kind of CO2The control method of the trapped DMC-PID cascade system comprises the following two steps:
in the first part, the smoke flow detected by a smoke flow sensor is quickly stabilized by adopting a conventional PID controller algorithm;
second part, for the control of the CO by PID controllers2The design method of the DMC controller by the aid of the generalized control object formed by the trapping process specifically comprises the following steps:
Step 1: setting k to be 1, setting the sampling time t to be 2s, setting the modeling time domain N to be 1200, setting the prediction time domain P to be 30, and controlling the time domain M to be 10 to satisfy that M is less than or equal to N and less than or equal to P;
step 2: initializing CO2Collecting process system parameters, v (1) w (1) e1(1) When the value is equal to 0, loop parameters of an inner loop module PID controller; y (1) ═ u (1) ═ e (1) ═ 0, the DMC controller loop parameter of the outer loop module;
step 3: the construction matrix A is a dynamic matrix and consists of a step response coefficient aiA constituent P M matrix;
step 4: according to the formula
Calculating v (1);
step 5: calculating an output error e (1) from the formula e (k) ═ u (k) — p (k);
step 6: according to the formula
Calculating an outer loop module DMC controller increment Δ u (k),.., Δ u (k + M-1);
step 7: setting a secondary performance index at the moment k:
step 8: calculating to obtain an inner ring module PID controller rule u (1) according to a formula u (k) ═ u (k-1) + delta u (k);
step 9: according to the formula
Calculating to obtain the PID controller rule of the inner ring module, and if v (k) is more than or equal to 10, v (k) is more than 10; if it is notv (k) is ≦ -10, then v (k) is-10;
step 10: according to the formula e1(k)＝w(k)-p1(k) Calculating to obtain the error e of the inner ring module PID controller1(1)；
Step 11: setting k to k +1, returning to step 4;
and at the moment k, calculating an output error e (k) of the current moment by using rolling prediction optimization, and simultaneously calculating a control increment delta u (k) of the current moment to the moment k +1 to obtain a new output error e (k +1) and a new control increment delta u (k +1), wherein the control algorithm is repeatedly carried out on line by combining the rolling optimization mode of feedback correction.
The modeling data is generated by Aspen Plus Dynamics simulation, random excitation signals are added to input ends of flue gas flow and lean solution flow to obtain an actual output curve of the system, and therefore open-loop experimental data of flue gas flow and lean solution flow changes to the carbon dioxide capture system are obtained. And (3) adopting a subspace identification method for the input and output data by utilizing the subspace identification principle, wherein the sampling time is set to be 36s according to the sampling period of an actual system. A fitted curve of the actual output and the predicted output of the system is obtained. According to the identification data, the system achieves 96.42% of fitting degree and achieves satisfactory fitting degree; and finally, the design of the DMC-PID cascade control system is completed.
This example is to compare the MEA-based post-combustion CO of the present invention2A DMC-PID cascade control method in a capture process adopts three control strategies of DMC-PID control, PID-PID control and DMC control to carry out experimental simulation comparison: simulation 1 As shown in FIG. 2, for a given ramp signal, with white Gaussian noise interference, CO2The comparison graph (the set value is a straight line) of the dynamic control effect of the medium flue gas flow under DMC-PID cascade control (dotted line), PID-PID cascade control (point horizontal line) and DMC control (point dotted line) in the trapping process can show that the DMC-PID cascade control method is superior to other two control methods in terms of overshoot, reaction time and the like; simulation 2 As shown in FIG. 3, given a step signal, CO 2Comparison of dynamic control Effect of trapping Rate in DMC-PID Cascade control (dotted line), PID-PID Cascade control (dot-and-dash line), and DMC control (dot-and-dash line) (set value is straight)Line), it can be seen that the DMC-PID cascade control method is superior to other two control methods in terms of overshoot, reaction time and the like, and can realize the rapid tracking of the capture rate to the set value, so that the method improves the CO2The operational quality of the capture system.
Claims (6)
1. CO (carbon monoxide)2Control method for trapped DMC-PID cascade system, comprising CO2Capture control module and CO2The capture and absorption module is characterized in that: the CO is2The trapping control module is arranged on the CO2The front end of the trapping and absorbing module; the CO is2The trapping control module mainly comprises an outer ring module and an inner ring module; the outer ring module is connected with the inner ring module in series; the outer ring module mainly consists of a DMC controller, and the inner ring module mainly consists of a PID controller; the DMC controller is sequentially connected with a PID controller and CO2A trapping and absorbing module; the CO is2End-mounted CO of capture absorption module2Content sensor, the CO2The content sensor is connected with the DMC controller, and the CO is2The starting end of the trapping and absorbing module is introduced into the combusted coal power plant flue gas through a flue gas pipeline, a flue gas flow sensor is mounted on the flue gas pipeline and used for detecting the flue gas flow of the coal power plant flue gas, and the flue gas flow sensor is connected with a PID controller; the CO is 2The capture absorption module mainly comprises an absorption tower and a stripping tower, and the absorption tower is connected with the stripping tower;
the control method comprises the following steps:
(1) by post-combustion CO2The trapping process is a controlled object, the lean liquid flow is used as the system input quantity, namely, the operation variable, the flue gas flow is used as the interference quantity, and CO2The method comprises the steps of firstly establishing a PCC process model in Aspen Plus, then carrying out open-loop test on the PCC process model, enabling the model to be stably simulated in Aspen Plus, setting pressure as a driving type, then leading out the model to Aspen Dynamics for dynamic simulation, and then carrying out a series of dynamic simulation on a controlled system according to actual industrial practical constraints of operation variables and interference and given values of controlled variablesThe step response test of the column specifically operates as follows: firstly, performing step response test on one of the operation variables, setting other variables to be unchanged, and obtaining dynamic response change of the controlled variable, so as to analyze the influence of each operation variable on the controlled variable and obtain related response data;
(2) then, carrying out model identification on the system based on a subspace identification method, wherein the method is characterized in that a parameter matrix of an estimated system model is extracted from a row subspace or a column subspace of a specific Hankel matrix by utilizing input and output data of the system; the state space model of the system can be identified directly by input and output data, the calculation efficiency is high, and the identification order is easy to select;
The subspace identification algorithm is divided into two steps:
the method comprises the steps of firstly, constructing a data Hankel matrix and an extended input and output matrix equation, and acquiring a generalized observability matrix gamma of a system through orthogonal projection, linear algebra tool QR decomposition, singular value decomposition and other methodsfOr estimation of a sequence of states XfObtaining the corresponding subspace;
secondly, determining a transfer function model of the system by a least square method and the like according to the obtained generalized observability matrix or state sequence estimation, wherein the set input variable of the DMC controller is CO2The set value of the content is calculated by the DMC controller to obtain the input value of the corresponding PID controller, and then the boundary value and the preset value of the DMC controller are adjusted in the industrial range of the operating variable and the controlled variable to obtain a DMC-PID cascade control system, thereby obtaining CO2The collection rate.
2. CO according to claim 12A method of controlling a trapped DMC-PID cascade system, characterized by: the outer ring module is a constant value system, and the inner ring module is a follow-up system.
3. CO according to claim 22A method of controlling a trapped DMC-PID cascade system, characterized by: setting DMC controller input variable to Outlet CO 2The set value of the content and the output signal are used as PID controlAnd (3) setting values of the controller, taking the inner ring flue gas flow as interference, monitoring the inner feedback as flue gas flow, detecting the outer ring feedback as flue gas content, and then adjusting the boundary value and the preset value of the DMC controller within the industrial range of an operation variable and a controlled variable to obtain the DMC-PID cascade control structure.
4. CO according to claim 32A method of controlling a trapped DMC-PID cascade system, characterized by: in the control method, the set value of a DMC controller is CO2And (4) content, the PID controller resists and eliminates high-frequency random interference brought by flue gas flow, and the DMC controller completes large-inertia large-lag control by a generalized object.
5. CO according to claim 42A method of controlling a trapped DMC-PID cascade system, characterized by: the method is based on post-combustion CO of MEA2And (4) trapping.
6. CO according to claim 52A method of controlling a trapped DMC-PID cascade system, characterized by: the method comprises the following two concrete steps:
in the first part, the smoke flow detected by a smoke flow sensor is quickly stabilized by adopting a conventional PID controller algorithm;
second part, for the control of the CO by PID controllers 2The design method of the DMC controller by the aid of the generalized control object formed by the trapping process specifically comprises the following steps:
step 1: setting k to be 1, setting sampling time t to be 2s, setting modeling time domain N to be 1200, setting prediction time domain P to be 30, and controlling time domain M to be 10 to satisfy that M is less than or equal to N and less than or equal to P;
step 2: initializing CO2Collecting process system parameters, v (1) w (1) e1(1) When the value is equal to 0, loop parameters of an inner loop module PID controller; y (1) ═ u (1) ═ e (1) ═ 0, the DMC controller loop parameter of the outer loop module;
step 3: the construction matrix A is a dynamic matrix and consists of a step response coefficient aiA constituent P M matrix;
step 4: according to the formula
Calculating v (1);
step 5: calculating an output error e (1) from the formula e (k) ═ u (k) — p (k);
step 6: according to the formula
Calculating an outer loop module DMC controller increment Δ u (k),.., Δ u (k + M-1);
step 7: setting a secondary performance index at the moment k:
step 8: calculating to obtain an inner ring module PID controller rule u (1) according to a formula u (k) ═ u (k-1) + delta u (k);
step 9: according to the formula
Calculating to obtain the PID controller rule of the inner ring module, and if v (k) is more than or equal to 10, v (k) is more than 10; if v (k) ≦ -10, v (k) ═ 10;
step 10: according to the formula e1(k)＝w(k)-p1(k) Calculating to obtain the error e of the inner ring module PID controller1(1)；
Step 11: setting k to k +1, returning to step 4;
and at the moment k, calculating an output error e (k) of the current moment by using rolling prediction optimization, and simultaneously calculating a control increment delta u (k) of the current moment to the moment k +1 to obtain a new output error e (k +1) and a new control increment delta u (k +1), wherein the control algorithm is repeatedly carried out on line by combining the rolling optimization mode of feedback correction.
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