Flexible cooperative control method for air exhaust system, medium and equipment

Abstract

The invention discloses a flexible cooperative control method for an air exhaust system, a medium and equipment, and relates to the technical field of air exhaust system control, and the method comprises the steps: constructing a second-order control system of the air exhaust system; defining an optimization problem of the air exhaust system, and designing a penalty function; designing a flexible control algorithm of the air exhaust system, designing an augmented objective function according to the penalty function and the flexible control algorithm, and converting an optimization problem; designing an ADRC controller according to the second-order control system; performing optimization iteration on parameters of the augmented objective function according to ADRC, and continuously updating a converted optimization problem; and cooperative control of the air exhaust system is carried out by combining the optimization problem which is continuously updated and converted and a proportional differential controller. The control efficiency and robustness of the air exhaust system are improved, and the safety of the compressor of the air exhaust system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air extraction system control, and in particular to a method, medium and equipment for flexible coordinated control of an air extraction system. Background Art

[0002] The aircraft engine high-altitude simulation test bench (referred to as the high-altitude test bench) is an indispensable and most effective and direct test device for the development of advanced aircraft engines and propulsion systems. As a key subsystem of the high-altitude test bench, the exhaust system simulates the engine test flight altitude by controlling the exhaust main pressure, and discharges the high-temperature and low-pressure combustion gas with variable flow rates generated during the engine test. As the core component of the exhaust system, the exhaust compressor unit controls the compressor pressure ratio within a safe operating range by adjusting the exhaust main pressure. As the flight speed and altitude of new aircraft continue to increase, the unknown disturbances to the engine are becoming more and more complex, which greatly increases the requirements for the exhaust system that provides environmental simulation conditions, posing a potential threat to the safe operation of the compressor unit.

[0003] At present, there are relatively rich studies on the air intake and exhaust systems of high-altitude platforms in China, but there is a relative lack of research on the exhaust system. The current research uses the "multi-valve linkage" method to achieve synchronous adjustment of the compressor unit, which is manually adjusted by experienced engineers. The resource utilization rate is low and the fault tolerance is poor. The safety control of the compressor unit has not been studied in depth. The problem of safe operation of the compressor unit can be transformed into an optimization problem with constraints. The penalty function method is one of the important ways to solve optimization problems with constraints. It can transform the optimization problem with constraints into an unconstrained optimization problem for solution, reducing the difficulty of solving the constrained optimization problem. There are many valves in the exhaust system. If the "linkage" idea is simply adopted, when a single compressor surges, all units can only be shut down and restarted, which wastes time and increases energy loss. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of poor fault tolerance of synchronous regulation of the current air extraction system, low resource utilization, and failure to consider the safety of the compressor unit, and propose a flexible collaborative control method for the air extraction system, comprising the following steps:

[0005] S1. Construct a second-order control system for the air extraction system;

[0006] S2. Define the optimization problem of the air extraction system and design the penalty function;

[0007] S3. Design a flexible control algorithm for the air extraction system, design an augmented objective function based on the penalty function and the flexible control algorithm, and transform the optimization problem;

[0008] S4. Design ADRC controller and PID controller based on the second-order control system;

[0009] S5. Optimize and iterate the parameters of the augmented objective function according to ADRC, and continuously update the transformed optimization problem;

[0010] S6. Combine the continuously updated transformed optimization problem, ADRC controller and PID controller to perform coordinated control of the air extraction system.

[0011] Furthermore, the air extraction system includes an air supply valve, an air extraction main pipe, an inlet valve, and a compressor, and the air supply valve, the air extraction main pipe, the inlet valve, and the compressor are connected in series in sequence;

[0012] The second-order control system for constructing the air extraction system is as follows:

[0013] The exhaust main pressure is expressed as follows:

[0014]

[0015] Among them, T c , p c , V are the temperature, pressure and volume of the exhaust main pipe respectively; c p is the specific heat capacity at constant pressure; R is the gas constant; h represents the enthalpy value of the exhaust main pipe; G in Indicates the gas flow rate flowing into the exhaust main pipe through the air supply valve; h in Indicates the enthalpy value at the inlet of the exhaust main; h out Indicates the enthalpy value of the exhaust main outlet; G out，i is the discharge flow rate of the i-th exhaust outlet; n is the number of exhaust outlets; Ω is the heat exchange capacity; represents the inlet valve flow coefficient; D represents the flow diameter; θ i Indicates the inlet valve opening;

[0016] The transfer function of the air supply valve flow rate and the exhaust main pipe pressure is expressed as:

[0017]

[0018] Among them, G1(s) represents the transfer function between the air supply valve flow rate and the exhaust main pressure, p c (s) means p c The Laplace transform of G in (s) represents G in Laplace transform of , s represents a complex variable, k a , k b The transfer function parameters representing the flow rate of the air supply valve and the pressure of the exhaust main pipe;

[0019] The air supply valve adopts a plunger valve. The position model of the air supply valve is a second-order inertia link, and the transfer function is expressed as:

[0020]

[0021] Where G2(s) represents the valve transfer function of the plunger valve, v p (s) means v p The Laplace transform of p Indicates the opening of the plunger valve, u p (s) means u p The Laplace transform of p Represents the input of the plunger valve, ω n represents the natural frequency;

[0022] The flow transfer function of the plunger valve is expressed as:

[0023]

[0024] make

[0025] Where G3(s) represents the flow transfer function of the plunger valve, Q p (s) means Q p The Laplace transform of p Indicates the valve flow rate of the plunger valve, k p Indicates the flow opening conversion ratio, represents the linear conversion coefficient, p 1，p Indicates the plunger valve inlet pressure, T 1，p Indicates the plunger valve inlet temperature, k Q It represents the flow transfer function parameters of the plunger valve;

[0026] The transfer function of the air extraction system is:

[0027]

[0028] Where G(s) represents the transfer function of the air extraction system, p c (s) means p c The Laplace transform of p (s) means u p The Laplace transform of p Indicates the input of the plunger valve;

[0029] The following second-order differential equation is obtained:

[0030]

[0031] Among them, a1 and a2 are the parameters of the air extraction system; b is the input gain of the air extraction system; w is the external disturbance caused by the inlet valve and compressor after the air extraction main pipe to the air extraction system.

[0032] Furthermore, the optimization problem of the air extraction system is expressed as:

[0033] min f(p c )

[0034] stg i (p c )≤0,i∈{1,2}

[0035] Among them, p c Indicates the pressure of the exhaust main, f(p c )=(p c -r set ) 2 , r set The target setting value for the exhaust main pressure;

[0036] g i (p c ) is expressed as:

[0037] g1(p c )=p r，min -p r

[0038] g2(p c )=p r -p r，max

[0039] in, Indicates the compressor pressure ratio, p out , p in is the compressor outlet and inlet pressure, p r，min and p r，max It is the lower and upper limits of the compressor safety pressure ratio.

[0040] Furthermore, the penalty function is designed as follows:

[0041] According to the optimization problem, the following auxiliary functions are defined:

[0042] L(p c , μ)=f(p c )+μα(p c )

[0043] Among them, L(p c , μ) is the auxiliary function, μ>0 is the penalty factor, α(p c ) is the penalty function. Combining the characteristics of the exponential function, the following penalty function is designed:

[0044]

[0045] Furthermore, the flexible control algorithm of the exhaust system is designed as follows:

[0046] Design corresponding flexible links for the safety of exhaust main pipe pressure and compressor pressure ratio respectively:

[0047] h1(p c )=||Δp c ||-ε1

[0048] h2(p r )=||Δp r ||-ε2

[0049] Among them, h1(p c ) and h2(p r ) represent the flexible link of the exhaust manifold pressure and the flexible link of the compressor pressure ratio, Δp c and Δp r denote the change rate of the exhaust manifold pressure and the change rate of the compressor pressure ratio, ε1 and ε2 denote the upper bounds of the state increments about the exhaust manifold pressure and the compressor pressure ratio, respectively, and |||| denotes the norm;

[0050] Combined with the penalty function, the flexible function β(p c , γ) is expressed as:

[0051]

[0052] Among them, β(p c , γ i ) represents the flexibility function, γ i >0 is the state adjustment coefficient, h i indicates h1(p c ) and h2(p r )One of them.

[0053] Furthermore, an augmented objective function is designed based on the penalty function and the flexible control algorithm to transform the optimization problem into:

[0054] The augmented objective function is expressed as:

[0055] F(p c , μ, σ, γ i )=f(p c )+μα(p c )+σβ(p c , γ i )

[0056] Among them, F(p c , μ, σ, γ i ) represents the augmented objective function, σ>0 is the flexibility factor, let η=[μ,σ], A=[α,β] T , the augmented objective function is expressed as:

[0057] F(p c ,η)=f(p c )+ηA(p c )

[0058] The optimization problem is transformed into:

[0059]

[0060] Furthermore, S4 is specifically:

[0061] Design a tracking differentiator to filter the compressor pressure ratio signal:

[0062]

[0063] Wherein, v0(t), v1(t), v2(t) are the tracking setpoint, the filtered compressor pressure ratio signal and the differential of the filtered compressor pressure ratio signal respectively; r is the fast factor;

[0064] Design the following PID controller:

[0065]

[0066] in, represents the i-th output of the PID controller; k P , k I , k D is the PID controller parameter, v 1，i (t) represents the compressor pressure ratio signal after the i-th filter, v 2，i (t) represents the differential of the i-th filtered compressor pressure ratio signal;

[0067] Expand the state of the exhaust system, the expanded state is x3(t), let Rewrite it into the state equation form:

[0068]

[0069] Where, the state variable x(t) = [x1(t), x2(t), x3(t)] T , x1 represents the main pipe pressure, x2 represents the derivative of the main pipe pressure, x3 represents the total disturbance of the air extraction system, u(t) represents the input of the air extraction system, y(t) represents the output of the air extraction system, A, B, C, E are related matrices, expressed as:

[0070]

[0071] According to the above state equation, the following ESO expression is obtained:

[0072]

[0073] In the formula, the state estimation ESO gain matrix L = [β 01 , β02 , β 03 ] T ; e(t) is the output state estimation error, represents the estimate of y(t), represents the first-order derivative of x(t).

[0074] Furthermore, the strategy for coordinated control of the air extraction system is as follows:

[0075]

[0076] Where u0(t) represents the output of ESO observation state after collaborative optimization, r(t) is the expected output of exhaust manifold pressure; feedback gain matrix K = [-k1, -k2]; where, is the collaborative optimization item of ESO, k3 is the optimization adjustment parameter of the collaborative optimization item of ESO, F() represents the designed objective function; u b (t) represents the output of the collaboratively optimized PID controller, i.e., the adjustment input of the inlet valve obtained according to the compressor pressure ratio signal. represents the output of the PID controller, is the collaborative optimization term of the PID controller; k B is the optimization adjustment parameter of the collaborative optimization item of the PID controller; e i Represents a column vector whose i-th element is 1 and other elements are all 0;

[0077] The input of the air supply valve of the air extraction system is expressed as:

[0078]

[0079] Among them, u p (t) represents the input of the air supply valve of the air extraction system.

[0080] The present invention further proposes a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned flexible collaborative control method of the air extraction system is implemented.

[0081] The present invention also proposes an electronic device, comprising a processor and a memory, wherein the processor and the memory are interconnected, wherein the memory is used to store a computer program, the computer program comprises computer-readable instructions, and the processor is configured to call the computer-readable instructions to execute the above-mentioned flexible collaborative control method of the exhaust system.

[0082] The beneficial effects brought by the technical solution provided by the present invention are:

[0083] The present invention aims at the problem of safe operation of the compressor unit, converts the safety problem into an optimization problem with inequality constraints, and converts the constrained optimization problem into an unconstrained optimization problem by designing penalty functions and flexible algorithms, ensuring that the compressor pressure ratio is within a safe range and improving the smoothness of control; in order to improve the efficiency and robustness of control and reduce the impact of external disturbances on the air extraction system, the current "multi-valve linkage" control method is improved, and a collaborative controller is designed by combining the PID algorithm, ADRC algorithm and system optimization. The present invention proposes solutions to the problems that the valves of the air extraction system of the high-altitude platform are still under manual control, the compressor safety of the air extraction system, and the severe valve vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 is a flow chart of a flexible cooperative control method for an air extraction system according to an embodiment of the present invention;

[0085] Figure 2 It is a schematic diagram of the operation of multiple compressor units of the air extraction system according to an embodiment of the present invention;

[0086] Figure 3 1 is a flexible cooperative anti-disturbance control framework diagram of an air extraction system according to an embodiment of the present invention;

[0087] Figure 4 is a block diagram of an electronic device in an exemplary embodiment of the present invention;

[0088] Figure 5 is a comparison chart of the simulation results of the flexible collaborative method and the individual control according to the embodiment of the present invention, wherein: Figure 5 (a) is a comparison of the main exhaust pipe pressure of the single control and the flexible coordination method of the present invention, Figure 5 (b) is a comparison of the inlet valve opening of the single control and the flexible coordination method of the present invention. Figure 5 (c) is a comparison of the compressor pressure ratios of the independent control and the flexible coordination method of the present invention. Figure 5 (d) is a comparison of the main pipe pressure regulating valve opening between the individual control and the flexible coordination method of the present invention. DETAILED DESCRIPTION

[0089] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0090] Example 1: A flowchart of the flexible cooperative control method of the air extraction system according to an embodiment of the present invention is as follows Figure 1 , specifically including the following steps:

[0091] S1. Construct a second-order control system for the air extraction system. The operation diagram of multiple compressor units in the air extraction system is as follows: Figure 2As shown, the air extraction system includes an exhaust control valve, a main pressure regulating valve (i.e., an air supply valve), an air extraction main pipe, and multiple sets of anti-surge compressor systems; the anti-surge compressor system includes: an inlet valve, an anti-surge valve, a compressor, a heat exchanger, and a vent valve. The compressor and the heat exchanger are connected in parallel, and the anti-surge valve is connected between the compressor and the heat exchanger. The inlet valve connects the air extraction main pipe and the compressor. The heat exchanger is mainly used in the cooling or heating process of the compressor. The heat between the fluids is transferred through heat exchange, so that the compressor can operate at different temperatures, reduce the power consumption of the compressor, and improve efficiency. The air extraction system is simplified. The air extraction system mainly includes: an air supply valve, an air extraction main pipe, an inlet valve, and a compressor. The air supply valve, the air extraction main pipe, the inlet valve, and the compressor are connected in series in sequence.

[0092] Since the exhaust gas from the engine needs to pass through multiple coolers to cool down when entering the exhaust system, it can be considered that the temperature of the main pipe is approximately constant (T c ≈const), the airflow and the pipe wall have entered a state of thermal equilibrium, and the enthalpy values ​​of all outlets of the exhaust main pipe are not much different and are basically equal.

[0093] The exhaust main pressure is expressed as follows:

[0094]

[0095] Among them, T c , p c , V are the temperature, pressure and volume of the exhaust main pipe respectively; c p is the specific heat capacity at constant pressure; R is the gas constant; h represents the enthalpy value of the exhaust main pipe; G in Indicates the gas flow rate flowing into the exhaust main pipe through the air supply valve; h in Indicates the enthalpy value at the inlet of the exhaust main; h out Indicates the enthalpy value of the exhaust main outlet; G out，i is the discharge flow rate of the i-th exhaust outlet; n is the number of exhaust outlets; Ω is the heat exchange capacity; represents the inlet valve coefficient; D represents the flow diameter; θ i Indicates the opening of the inlet valve.

[0096] The transfer function of the air supply valve flow rate and the exhaust main pipe pressure is expressed as:

[0097]

[0098] Where G1(s) represents the transfer function between the air supply valve flow rate and the exhaust main pressure, p c (s) means p c The Laplace transform of G in (s) represents G in The Laplace transform of .

[0099] The air supply valve adopts a plunger valve, and its valve position model is a second-order inertia link, and the transfer function is expressed as:

[0100]

[0101] Where G2(s) represents the valve transfer function of the plunger valve, v p (s) means v p The Laplace transform of p Indicates the opening of the plunger valve, u p (s) means u p The Laplace transform of p Represents the input of the plunger valve, ω n represents the natural frequency, and s represents a complex variable.

[0102] The flow transfer function of the plunger valve is expressed as:

[0103]

[0104] Where G3(s) represents the flow transfer function of the plunger valve, Q p (s) means Q p The Laplace transform of p Indicates the valve flow rate of the plunger valve, k p Indicates the flow opening conversion ratio, represents the linear conversion coefficient, p 1，p Indicates the plunger valve inlet pressure, T 1，p Indicates the plunger valve inlet temperature.

[0105] The transfer function of the air extraction system is:

[0106]

[0107] Where G(s) represents the transfer function of the air extraction system, p c (s) means o c The Laplace transform of p (s) means u p The Laplace transform of .

[0108] The following second-order differential equation is obtained:

[0109]

[0110] Among them, a1 and a2 are the parameters of the air extraction system; b is the input gain of the air extraction system; w is the external disturbance caused by the inlet valve and compressor after the air extraction main pipe to the system, k a , k b k represents the transfer function parameter between the air supply valve flow rate and the exhaust main pressure, Q Represents the flow transfer function parameters of the plunger valve.

[0111] S2. Define the optimization problem of the air extraction system and design the penalty function.

[0112] For the exhaust system, the safe operation of the compressor is the primary task. At the same time, the exhaust main pressure p c Establish the required pressure for flight conditions. Compressor safety issues are generally related to compressor surge and blocking. Surge is the main instability phenomenon found in centrifugal compressors, characterized by large oscillations of pressure and mass flow in the system. Compressor pressure ratio p r It is an important indicator to measure the safety of the compressor, expressed as the ratio of the pressure after the compressor to the pressure before the compressor.

[0113] Considering that the compressor pressure ratio is constrained within a certain range, the optimization problem of the air extraction system with inequality constraints is expressed as:

[0114] minf(p c )

[0115] stg i (p c )≤0,i∈{1,2},

[0116] Among them, p c Indicates the pressure of the exhaust main, f(p c )=(p c -r set ) 2 , r set It is the target setting value for the exhaust main pressure control.

[0117] Safe range of compressor pressure ratio g i (p c ) is expressed as:

[0118] g1(p c )=p r，min -p r

[0119] g2(p c )=p r -p r，max ,

[0120] in, Indicates the compressor pressure ratio, p out , p in is the compressor outlet and inlet pressure, p r，min and p r，max It is the lower and upper limits of the compressor safety pressure ratio.

[0121] The penalty function is designed as follows:

[0122] According to the optimization problem, the following auxiliary functions are defined:

[0123] L(p c , μ)=f(p c )+μα(p c )

[0124] Among them, L(p c , μ) is the auxiliary function, μ>0 is the penalty factor, α(p c ) is the penalty function. Combining the characteristics of the exponential function, the following penalty function is designed:

[0125]

[0126] S3. Design a flexible control algorithm for the air extraction system, design an augmented objective function based on the penalty function and the flexible control algorithm, and transform the optimization problem.

[0127] Design corresponding flexible links for the safety of exhaust main pipe pressure and compressor pressure ratio respectively:

[0128] h1(p c )=||Δp c ||-ε1

[0129] h2(p r )=||Δp r ||-ε2

[0130] Among them, h1(p c ) and h2(p r ) represent the flexible link of the exhaust manifold pressure and the flexible link of the compressor pressure ratio, respectively. c Indicates the exhaust main pressure, p r Indicates the compressor pressure ratio, Δp c and Δp r They respectively represent the rate of change of the exhaust main pressure and the rate of change of the compressor pressure ratio, ε1 and ε2 respectively represent the upper bounds of the state increment regarding the exhaust main pressure and the compressor pressure ratio, and |||| represents the norm.

[0131] Combined with the penalty function, the flexible function β(p c , γ) is expressed as:

[0132]

[0133] Among them, β(p c , γ i ) represents the flexibility function, γ i >0 is the state adjustment coefficient, h i indicates h1(p c ) and h2(p r )One of them.

[0134] Design the augmented objective function based on the penalty function and flexible control algorithm:

[0135] F(p c , μ, σ, γ i )=f(p c )+μα(p c )+σβ(p c , γ i )

[0136] Among them, F(p c , μ, σ, γ i ) represents the augmented objective function, σ>0 is the flexibility factor, let η=[μ,σ], A=[α,β] T , the augmented objective function is expressed as:

[0137] F(p c ,η)=f(p c )+ηA(p c );

[0138] The optimization problem is transformed into:

[0139]

[0140] When the system reaches the optimal state, the optimal value of the augmented objective function is At the same time, ensure that the compressor is in a safe operating range and the exhaust main pressure reaches the expected value.

[0141] S4. Based on the second-order control system, design ADRC controller and PID controller.

[0142] In order to obtain the differential signal of the pressure ratio and reduce the pressure ratio measurement error and noise, a tracking differentiator (TD) is designed to filter the pressure ratio signal and extract its differential term, which is expressed as:

[0143]

[0144] Wherein, v0(t), v1(t), and v2(t) are the differentials of the tracking setpoint, the filtered compressor pressure ratio signal (i.e., the tracking signal), and the filtered compressor pressure ratio signal, respectively; r is the fast factor;

[0145] Design the following PID controller:

[0146]

[0147] in, represents the ith output of the PID controller, k P , k I , k D is the PID controller parameter, v 1，i(t) represents the compressor pressure ratio signal after the i-th filter, v 2，i (t) represents the differential of the compressor pressure ratio signal after the i-th filter, and v0(t) represents the expected value of the pressure ratio, that is, the tracking set value.

[0148] Use the extended state observer (ESO) to expand the system state, the expanded state is x3(t), let Rewrite it into the state equation form:

[0149]

[0150] Where y(t) represents the output of the air extraction system, and the state variable x(t) = [x1(t), x2(t), x3(t)] T , x1 represents the main pipe pressure, x2 represents the derivative of the main pipe pressure, x3 represents the total disturbance of the exhaust system, u(t) represents the input of the exhaust system, and the correlation matrix is:

[0151]

[0152] According to the above state equation, the following ESO expression is obtained:

[0153]

[0154] In the formula, the state estimation ESO gain matrix L = [β 01 , β 02 , β 03 ] T ; e(t) is the output state estimation error, represents the estimate of y(t), represents the first-order derivative of x(t), where x(t) represents the state of the system.

[0155] S5. According to ADRC, the parameters of the augmented objective function are optimized and iterated, and the transformed optimization problem is continuously updated.

[0156] The parameters of the augmented objective function are optimized and iterated based on the difference between the state x1 observed by the ESO and the expected value of the exhaust main pressure and the tracking signal v1 of the tracking differentiator.

[0157] S6. Combine the continuously updated transformed optimization problem and the proportional differential controller to carry out coordinated control of the air extraction system.

[0158] The strategy for coordinated control of the air extraction system is as follows:

[0159]

[0160] Where u0(t) represents the output of the ESO observation state after collaborative optimization, r(t) is the expected output of the exhaust manifold pressure (pressure expectation); the feedback gain matrix K = [-k1, -k2]; where, is the collaborative optimization item of ESO, k3 is the optimization adjustment parameter of the collaborative optimization item of ESO, F() represents the designed optimization objective function; u b (t) represents the output of the collaboratively optimized PID controller, i.e., the adjustment input of the inlet valve obtained according to the compressor pressure ratio signal. represents the output of the PID controller, is the collaborative optimization term of the PID controller; k B is the optimization adjustment parameter of the collaborative optimization item of the PID controller; e i Represents a column vector whose i-th element is 1 and all other elements are 0.

[0161] The input of the air supply valve of the air extraction system is expressed as:

[0162]

[0163] Among them, u p (t) represents the output of the ADRC controller and is also the input of the air supply valve of the air extraction system.

[0164] The flexible cooperative anti-disturbance control framework diagram of the air extraction system of the embodiment of the present invention is referenced Figure 3 .minF k (p c，k , η k ) is the optimization problem after the kth iteration, p c，k represents the pressure of the exhaust main after the kth iteration, η k represents η after the kth iteration.

[0165] Embodiment 2: In an exemplary embodiment, a computer-readable storage medium is included, and the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned flexible collaborative control method of the exhaust system is implemented.

[0166] Example 3: Please refer to Figure 4 In an exemplary embodiment, an electronic device is also included, including at least one processor, at least one memory, and at least one communication bus.

[0167] Among them, a computer program is stored in the memory, and the computer program includes computer-readable instructions. The processor calls the computer-readable instructions stored in the memory through the communication bus to execute the above-mentioned flexible collaborative control method of the exhaust system.

[0168] The simulation experiment is designed to verify the effectiveness of the method of the present invention. Since the designed algorithm is mainly aimed at the safety problem of the compressor, the influence of the compressor pressure ratio change and external disturbance on the exhaust main pressure under various complex working conditions is considered. The simulation considers the situation where two compressors work at the same time, and considers the compressor backflow startup and backflow grid connection process. In the initial state, the inlet valves are all closed, the anti-surge valve is fully open, the main pipe pressure regulating valve is selected to be fully closed, and the vent valve is also in a fully closed state; when the final value state is reached, the unit inlet valve is fully open, the anti-surge valve is fully closed, the main pipe pressure regulating valve is opened to a certain angle, and the exhaust main pressure is established and reaches a stable state. At present, the working pressure ratio of the exhaust compressor unit ranges from 2.5 to 9.5, the surge protection pressure ratio is about 10.5, and the compressor pressure ratio is kept within the safe pressure ratio range of 4.0 to 6.0 during the whole process. Considering only the first-stage exhaust situation, the exhaust main pressure gradually transitions from the initial atmospheric pressure (about 95.5kPa) to the initial exhaust main pressure setting value. Comparing the simulation results of the designed flexible collaborative control method with the single control "multi-valve linkage" method, such as Figure 5 As shown, Figure 5 is a comparison chart of the simulation results of the flexible collaborative method and the individual control according to the embodiment of the present invention, wherein: Figure 5 (a) is a comparison of the main exhaust pipe pressure of the single control and the flexible coordination method of the present invention, Figure 5 (b) is a comparison of the inlet valve opening of the single control and the flexible coordination method of the present invention. Figure 5 (c) is a comparison of the compressor pressure ratios of the independent control and the flexible coordination method of the present invention. Figure 5 (d) is a comparison of the main pipe pressure regulating valve opening between the individual control and the flexible coordination method of the present invention.

[0169] The simulation results show that the flexible cooperative anti-disturbance control method has a faster adjustment speed for the main pipe pressure than the single control method, shortens the time to reach steady state by 30s, and eliminates the control overshoot. The root mean square errors of the exhaust main pipe pressure of the single control and flexible cooperative anti-disturbance control are 53.64 and 5.58 respectively, and the root mean square error of the proposed method is much smaller than that of the single control. For the compressor pressure ratio, the flexible cooperative anti-disturbance control compressor pressure ratio can be guaranteed to be within the safe pressure ratio range throughout the whole process, while the single control will increase the pressure ratio during the reflux start-up process and exceed the safe range at 107~307s. In addition, the flexible cooperative anti-disturbance control controls the main pipe pressure regulating valve more smoothly, and the valve swing is significantly reduced from the original 2% to 0.25%, reducing the probability of valve failure.

[0170] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible cooperative control method for an air extraction system, characterized in that: The following steps are involved: S1. Construct a second-order control system for the air extraction system; S2. Define the optimization problem of the air extraction system and design the penalty function; S3. Design a flexible control algorithm for the air extraction system, design an augmented objective function based on the penalty function and the flexible control algorithm, and transform the optimization problem; S4. Design ADRC controller and PID controller based on the second-order control system; S5. Optimize and iterate the parameters of the augmented objective function according to ADRC, and continuously update the transformed optimization problem; S6. Combine the continuously updated transformed optimization problem, ADRC controller and PID controller to perform coordinated control of the air extraction system.

2. A flexible cooperative control method for an air extraction system according to claim 1, characterized in that: The air extraction system includes an air supply valve, an air extraction main pipe, an inlet valve, and a compressor, and the air supply valve, the air extraction main pipe, the inlet valve, and the compressor are connected in series in sequence; The second-order control system for constructing the air extraction system is as follows: The exhaust main pressure is expressed as follows: Among them, T c ,p c , V are the temperature, pressure and volume of the exhaust main pipe respectively; c p is the specific heat capacity at constant pressure; R is the gas constant; h represents the enthalpy value of the exhaust main pipe; G in Indicates the gas flow rate flowing into the exhaust main pipe through the air supply valve; h in Indicates the enthalpy value at the inlet of the exhaust main; h out Indicates the enthalpy value of the exhaust main outlet; G out,i is the discharge flow rate of the i-th exhaust outlet; n is the number of exhaust outlets; Ω is the heat exchange capacity; represents the inlet valve flow coefficient; D represents the flow diameter; θ i Indicates the inlet valve opening; The transfer function of the air supply valve flow rate and the exhaust main pipe pressure is expressed as: Among them, G1(s) represents the transfer function between the air supply valve flow rate and the exhaust main pressure, p c (s) means p c The Laplace transform of G in (s) represents G in Laplace transform of , s represents a complex variable, k a , k b The transfer function parameters representing the flow rate of the air supply valve and the pressure of the exhaust main pipe; The air supply valve adopts a plunger valve. The position model of the air supply valve is a second-order inertia link, and the transfer function is expressed as: Where G2(s) represents the valve transfer function of the plunger valve, v p (s) means v p The Laplace transform of p Indicates the opening of the plunger valve, u p (s) means u p The Laplace transform of p Represents the input of the plunger valve, ω n represents the natural frequency; The flow transfer function of the plunger valve is expressed as: make Where G3(s) represents the flow transfer function of the plunger valve, Q p (s) means Q p The Laplace transform of p Indicates the valve flow rate of the plunger valve, k p Indicates the flow opening conversion ratio, represents the linear conversion coefficient, p 1，p Indicates the plunger valve inlet pressure, T 1，p Indicates the plunger valve inlet temperature, k Q It represents the flow transfer function parameters of the plunger valve; The transfer function of the air extraction system is: Where G(s) represents the transfer function of the air extraction system, p c (s) means p c The Laplace transform of p (s) means u p The Laplace transform of p Indicates the input of the plunger valve; The following second-order differential equation is obtained: Among them, a1 and a2 are the parameters of the air extraction system; b is the input gain of the air extraction system; w is the external disturbance caused by the inlet valve and compressor after the air extraction main pipe to the air extraction system.

3. A flexible cooperative control method for an air extraction system according to claim 2, characterized in that: The optimization problem of the air extraction system is expressed as: minf(p c ) s.t.g i (p c )≤0,i∈{1,2} Among them, p c Indicates the pressure of the exhaust main, f(p c )=(p c -r set ) 2 , r set The target setting value for the exhaust main pressure; g i (p c ) is expressed as: g1(p c )=p r,min -p r g2(p c )=p r -p r,max in, Indicates the compressor pressure ratio, p out ,p in is the compressor outlet and inlet pressure, p r,min and p r,max It is the lower and upper limits of the compressor safety pressure ratio.

4. A flexible cooperative control method for an air extraction system according to claim 3, characterized in that: The penalty function is designed as follows: According to the optimization problem, the following auxiliary functions are defined: L(p c ,μ)=f(p c )+ma(p c ) Among them, L(p c ,μ) is the auxiliary function, μ>0 is the penalty factor, α(p c ) is the penalty function. Combining the characteristics of the exponential function, the following penalty function is designed:

5. A flexible cooperative control method for an air extraction system according to claim 4, characterized in that: The flexible control algorithm for the designed air extraction system is as follows: Design corresponding flexible links for the safety of exhaust main pipe pressure and compressor pressure ratio respectively: h1(p c )=||Δp c ||-e1 h2(p r )=||Δp r ||-ε2 Among them, h1(p c ) and h2(p r ) represent the flexible link of the exhaust manifold pressure and the flexible link of the compressor pressure ratio, Δp c and Δp r denote the change rate of the exhaust manifold pressure and the change rate of the compressor pressure ratio, ε1 and ε2 denote the upper bounds of the state increments about the exhaust manifold pressure and the compressor pressure ratio, respectively, and || || denotes the norm; Combined with the penalty function, the flexible function β(p c , γ) is expressed as: Among them, β(p c , γ i ) represents the flexibility function, γ i >0 is the state adjustment coefficient, h i indicates h1(p c ) and h2(p r )One of them.

6. A flexible cooperative control method for an air extraction system according to claim 5, characterized in that: The augmented objective function is designed according to the penalty function and the flexible control algorithm, and the optimization problem is transformed into: The augmented objective function is expressed as: F(p c ,m,s,g i )=f(p c )+ma(p c )+sb(p c ,c i ) Among them, F(p c , μ, σ, γ i ) represents the augmented objective function, σ>0 is the flexibility factor, let η=[μ,σ], A=[α,β] T , the augmented objective function is expressed as: F(p c ,η)=f(p c )+ηA(p c ) The optimization problem is transformed into:

7. A flexible cooperative control method for an air extraction system according to claim 6, characterized in that: S4 is specifically: Design a tracking differentiator to filter the compressor pressure ratio signal: Wherein, v0(t), v1(t), v2(t) are the tracking setpoint, the filtered compressor pressure ratio signal and the differential of the filtered compressor pressure ratio signal respectively; r is the fast factor; Design the following PID controller: in, represents the i-th output of the PID controller; k P , k I , k D is the PID controller parameter, v 1,i (t) represents the compressor pressure ratio signal after the i-th filter, v 2,i (t) represents the differential of the i-th filtered compressor pressure ratio signal; Expand the state of the exhaust system, the expanded state is x3(t), let Rewrite it into the state equation form: In the formula, the state variable x(t) = [x1(t), x2(t), x3(t)] T , x1 represents the main pipe pressure, x2 represents the derivative of the main pipe pressure, x3 represents the total disturbance of the air extraction system, u(t) represents the input of the air extraction system, y(t) represents the output of the air extraction system, A, B, C, E are related matrices, expressed as: According to the above state equation, the following ESO expression is obtained: In the formula, the state estimation ESO gain matrix L = [β 01 ,β 02 ,β 03 ] T ; e(t) is the output state estimation error, represents the estimate of y(t), represents the first-order derivative of x(t).

8. A flexible cooperative control method for an air extraction system according to claim 7, characterized in that: The strategy for coordinated control of the air extraction system is as follows: Where u0(t) represents the output of ESO observation state after collaborative optimization, r(t) is the expected output of exhaust manifold pressure; feedback gain matrix K = [-k1, -k2]; where, is the collaborative optimization item of ESO, k3 is the optimization adjustment parameter of the collaborative optimization item of ESO, F() represents the designed objective function; u b (t) represents the output of the collaboratively optimized PID controller, i.e., the adjustment input of the inlet valve obtained according to the compressor pressure ratio signal. represents the output of the PID controller, is the collaborative optimization term of the PID controller; k B is the optimization adjustment parameter of the collaborative optimization item of the PID controller; e i Represents a column vector whose i-th element is 1 and other elements are all 0; The input of the air supply valve of the air extraction system is expressed as: Among them, u p (t) represents the input of the air supply valve of the air extraction system.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

10. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the processor and the memory are interconnected, wherein the memory is used to store a computer program, the computer program comprises computer-readable instructions, and the processor is configured to call the computer-readable instructions to execute the method according to any one of claims 1 to 8.

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