Compressor power tracking and backpressure adjusting cooperative control method

Abstract

The invention relates to the technical field of compressed air energy storage, in particular to a compressor power tracking and backpressure adjustment cooperative control method which comprises the steps that the operation mode and operation parameters of a compressor are recognized; if the operation mode is a first operation mode, the target power tracking and backpressure adjustment cooperative control mode is that the backpressure and the power of a compressor are adjusted according to the opening degree of an outlet throttle valve; if the operation mode is a second operation mode and a third operation mode, the target power tracking and backpressure adjustment cooperative control mode is that the backpressure and the power of the compressor are adjusted according to the rotating speed, the inlet guide vane angle and the opening degree of an outlet throttle valve; and the backpressure and power of the compressor are adjusted based on the target power tracking and backpressure adjustment cooperative control mode. Therefore, the problem that a single outlet throttling mode of a traditional mode is difficult to achieve wide working condition flexible regulation and control and power tracking in a large pressure ratio range in the compression link is solved.

Description

Technical Field

[0001] The present application relates to the technical field of compressed air energy storage, and in particular to a method for coordinated control of compressor power tracking and back pressure regulation. Background Art

[0002] Changes in environmental conditions, changes in external loads, and changes in outlet back pressure caused by the linear increase in gas storage pressure during compression and inflation, all work together to cause the compressor to be in a variable operating state for a long time. Among them, the variable operating condition caused by changes in gas storage pressure runs through the entire process of compression and power generation. The compression performance of the compressor under variable back pressure has a significant impact on the overall energy storage efficiency and energy storage density of the AA-CAES system. By installing a throttle valve at the outlet of the compressor and adjusting the valve opening according to changes in gas storage pressure to achieve pressure matching on both sides, constant pressure operation on the compression side can be achieved. Studies have shown that installing a throttle valve at the outlet of the compressor to keep it running at the optimal back pressure can further improve the compression efficiency. However, the throttling process itself is accompanied by a large amount of pressure loss, which wastes a lot of useful energy and reduces the cycle efficiency of the system.

[0003] Considering the response to changes in air pressure, the main operating modes of compressed air energy storage power stations are fixed pressure operation, sliding pressure operation, and pressure regulation operation. In the fixed pressure mode, the outlet throttling method is usually used to adjust the compression back pressure. In the sliding pressure and pressure regulation modes, the compressor back pressure changes greatly with the pressure of the gas storage reservoir. A single outlet throttling method is difficult to achieve flexible regulation of the compression link under a wide range of pressure ratios. Summary of the invention

[0004] The present application provides a coordinated control method of compressor power tracking and back pressure regulation to solve the problem that the traditional single outlet throttling method is difficult to achieve flexible regulation of the compression link under a wide range of pressure ratios.

[0005] The first aspect of the present application provides a method for coordinated control of compressor power tracking and back pressure regulation, comprising the following steps: identifying the operating mode and operating parameters of the compressor, and converting them into a MIMO problem, wherein the operating mode includes the first to third modes, and the operating parameters include the speed, the inlet guide vane angle, and the outlet throttle valve opening; determining the coordinated control mode of target power tracking and back pressure regulation of the compressor according to the operating mode and the operating parameters, wherein if the operating mode is the first operating mode, the coordinated control mode of target power tracking and back pressure regulation is: regulating the compressor back pressure and power according to the outlet throttle valve opening; if the operating mode is the second operating mode and the third operating mode, the coordinated control mode of target power tracking and back pressure regulation is: regulating the compressor back pressure and power according to multiple speed, inlet guide vane angle and outlet throttle valve opening; regulating the compressor back pressure and power based on the coordinated control mode of target power tracking and back pressure regulation.

[0006] Optionally, the first operating mode is an operating mode in which the compressor back pressure remains unchanged, the second operating mode and the third operating mode are both operating modes in which the compressor back pressure changes, the last stage compression back pressure in the second operating mode is equal to the gas storage pressure, and the last stage compression back pressure in the third operating mode is greater than or equal to the gas storage pressure.

[0007] Optionally, if the operation mode is the first operation mode, the final stage compression back pressure or the first stage turbine inlet pressure is maintained at the design value.

[0008] Optionally, the compressor back pressure and power are adjusted according to multiple factors such as the speed, inlet guide vane angle and outlet throttle valve opening, including: if the operating mode is the second operating mode, the compressor back pressure and power are adjusted according to the speed and inlet guide vane angle; if the operating mode is the third operating mode, the compressor back pressure and power are adjusted according to the speed, inlet guide vane angle and outlet throttle valve opening.

[0009] Optionally, the compressor back pressure and power are adjusted according to multiple factors such as the speed, inlet guide vane angle and outlet throttle valve opening, including: inputting multiple factors such as the speed, inlet guide vane angle and outlet throttle valve opening into a multi-control quantity collaborative control model, the multi-control quantity collaborative control model outputting compressor back pressure and power increments; adjusting the compressor back pressure and power according to the compressor back pressure and power increments until the real-time back pressure and power of the compressor reach within a preset range of the target back pressure and power, and then adjusting the compressor back pressure and power according to the deviation between the real-time back pressure and the target back pressure.

[0010] Optionally, the multi-control variable collaborative control model is:

[0011] J(x(k),U(k))=||αY(k+n|k)|| 2 +||βU(k)|| 2

[0012] Among them, the compressor power command and back pressure increment prediction function ||αY(k+n|k)|| 2 , α corresponds to the output weight matrix, β corresponds to the control weight matrix, U(k) represents the vector sequence composed of n-step control quantities, and Y(k+n|k) corresponds to the sequence composed of n-step predicted outputs.

[0013] Optionally, the multi-control variable cooperative control model includes multi-control variable constraints and compressor back pressure and power coupling constraints, wherein:

[0014] The constraints of multiple control variables are:

[0015]

[0016] in, and are the minimum speed and the maximum speed respectively, and are the minimum and maximum inlet guide vane angles, λ TVc and are the minimum and maximum throttle valve openings, and are the minimum and maximum flow rates respectively, the subscript i represents the number of compression stages,

[0017] If the operation mode is the second operation mode, the compressor back pressure and power coupling constraint condition is that the final stage compression back pressure must be kept equal to the gas storage pressure in real time:

[0018]

[0019] If the operation mode is the third operation mode, the compressor back pressure and power coupling constraint condition is:

[0020]

[0021] Among them, P c is the total compression power, Power command reference value, is the back pressure of the final compressor; p AS is the gas storage pressure, p TV It is the minimum pressure difference on both sides of the throttle valve.

[0022] Therefore, this application includes the following beneficial effects:

[0023] The embodiment of the present application can identify the operation mode and operation parameters of the compressor, and determine the target power tracking and back pressure regulation coordinated control mode of the compressor according to the operation mode and operation parameters, and finally adjust the compressor back pressure and power based on the target power tracking and back pressure regulation coordinated control mode, so as to realize the compressed air energy storage power station under different operation modes, and ensure the flexible regulation of the compressor back pressure and power under wide working conditions. Thus, the problem that the traditional single outlet throttling method is difficult to achieve flexible regulation of the compression link under wide working conditions under a large pressure ratio range is solved.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 It is a flow chart of a compressor power tracking and back pressure regulation coordinated control method provided according to an embodiment of the present application;

[0027] Figure 2The figure is a schematic diagram of adjusting the compressor operating point according to different control methods provided in one embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] The following describes the coordinated control method of compressor power tracking and back pressure regulation in an embodiment of the present application with reference to the accompanying drawings. In view of the problem mentioned in the above background technology that the single outlet throttling method of the traditional method is difficult to achieve flexible regulation of the compression link under a wide range of pressure ratios, the present application provides a coordinated control method of compressor power tracking and back pressure regulation. In this method, by identifying the operating mode and operating parameters of the compressor, and determining the target power tracking and back pressure regulation coordinated control method of the compressor according to the operating mode and operating parameters, and finally adjusting the compressor back pressure and power based on the target power tracking and back pressure regulation coordinated control method, the compressed air energy storage power station is realized in different operating modes. Flexible regulation of compressor back pressure and power under wide conditions. Thus, the problem that the single outlet throttling method of the traditional method is difficult to achieve flexible regulation of the compression link under a wide range of pressure ratios is solved.

[0030] Specifically, Figure 1 A flow chart of a coordinated control method of compressor power tracking and back pressure regulation provided in an embodiment of the present application.

[0031] like Figure 1 As shown, the compressor power tracking and back pressure regulation coordinated control method includes the following steps:

[0032] In step S101 , the operation mode and operation parameters of the compressor are identified, wherein the operation mode includes the first to third modes, and the operation parameters include the rotation speed, the inlet guide vane angle, and the outlet throttle valve opening.

[0033] Among them, the first to third operating modes respectively specify the pressure mode, sliding pressure mode and pressure regulation mode, which will be described in detail below and will not be repeated here; the speed refers to the number of revolutions per minute of the rotating mechanical parts when the compressor is running; the inlet guide vane refers to a group of blades located at the inlet of the compressor, and the gas flow entering the compressor can be controlled by changing the inlet guide vane angle; adjusting the outlet throttle valve opening can adjust the pressure and flow of the gas discharged from the compressor; the operating parameters can be obtained through sensors.

[0034] It can be understood that the embodiment of the present application first identifies the operating mode and operating parameters of the compressor, and the operating modes of the compressor include a first operating mode, a constant pressure mode, a second operating mode, a sliding pressure mode, and a third operating mode, a pressure regulating mode; the operating parameters include the speed, the inlet guide vane angle, and the outlet throttle valve opening, which can be obtained through sensors, for example, the speed can be obtained through a speed sensor.

[0035] In the embodiment of the present application, the first operating mode is an operating mode in which the compressor back pressure remains unchanged, the second operating mode and the third operating mode are both operating modes in which the compressor back pressure changes, the final stage compression back pressure in the second operating mode is equal to the gas storage pressure, and the final stage compression back pressure in the third operating mode is greater than or equal to the gas storage pressure.

[0036] Among them, the first operating mode is the constant pressure mode, in which the compressor back pressure remains unchanged; the second operating mode and the third operating mode are respectively the sliding pressure mode and the pressure regulating mode, both of which are operating modes in which the compressor back pressure will change; the compressor back pressure is the pressure at the outlet end of the compressor, that is, the pressure encountered when the compressor discharges gas.

[0037] It can be understood that the first operating mode of the embodiment of the present application is a constant pressure mode, the second operating mode and the third operating mode are a sliding pressure mode and a pressure regulating mode, respectively. In the first operating mode, the compressor back pressure and power remain unchanged; in the second operating mode, the compressor back pressure and power will change significantly with the gas storage pressure. Since the throttle valve's regulating effect on pressure and flow is not considered, the final stage compression back pressure needs to be equal to the gas storage pressure; the third operating mode combines the pressure regulating effect of the throttle valve in the constant pressure mode with the efficiency advantage of the sliding pressure operation, and the final stage compression back pressure is greater than or equal to the gas storage pressure.

[0038] In step S102, the coordinated control mode of target power tracking and back pressure regulation of the compressor is determined according to the operation mode and the operation parameters, wherein, if the operation mode is the first operation mode, the coordinated control mode of target power tracking and back pressure regulation is: adjusting the compressor back pressure and power according to the outlet throttle valve opening; if the operation mode is the second operation mode and the third operation mode, the coordinated control mode of target power tracking and back pressure regulation is: adjusting the compressor back pressure and power according to multiple speed, inlet guide vane angle and outlet throttle valve opening.

[0039] It can be understood that in the embodiment of the present application, there are two types of coordinated control methods of target power tracking and back pressure regulation. When the operating mode is identified as the first operating mode, the corresponding coordinated control method of target power tracking and back pressure regulation is the first type, that is, the compressor back pressure and power are adjusted according to the outlet throttle valve opening; when the operating mode is identified as the second operating mode and the third operating mode, the corresponding coordinated control method of target power tracking and back pressure regulation is the second type, that is, the compressor back pressure and power are adjusted according to multiple factors such as the speed, the inlet guide vane angle and the outlet throttle valve opening.

[0040] In step S103, the compressor back pressure and power are adjusted based on the target power tracking and back pressure regulation coordinated control method.

[0041] It can be understood that after the embodiment of the present application identifies the operating mode, it determines the target power tracking and back pressure regulation collaborative control method, and adjusts the compressor back pressure and power based on the target power tracking and back pressure regulation collaborative control method.

[0042] In the embodiment of the present application, if the operation mode is the first operation mode, the final stage compression back pressure or the first stage turbine inlet pressure is maintained at the design value.

[0043] Among them, the first-stage turbine inlet pressure refers to the gas pressure in front of the first-stage blades of the turbine; the last-stage compression back pressure refers to the gas pressure faced at the outlet of the last-stage compressor; the design value is the gas pressure value set through calculation and experiment, and is not specifically limited here; the last-stage compression back pressure or the first-stage turbine inlet pressure can be adjusted by the outlet throttle valve opening to maintain it at the design value.

[0044] It can be understood that if the embodiment of the present application identifies that the operating mode is the first operating mode, the outlet throttle valve opening is controlled to maintain the last stage compression back pressure or the first stage turbine intake pressure at the design value.

[0045] In an embodiment of the present application, the compressor back pressure and power are adjusted according to multiple factors including the speed, the inlet guide vane angle and the outlet throttle valve opening, including: if the operating mode is the second operating mode, the compressor back pressure and power are adjusted according to the speed and the inlet guide vane angle; if the operating mode is the third operating mode, the compressor back pressure and power are adjusted according to the speed, the inlet guide vane angle and the outlet throttle valve opening.

[0046] It can be understood that in the embodiment of the present application, when the operating mode is identified as the second operating mode, the compressor back pressure and power are adjusted according to the speed and the inlet guide vane angle, which can meet the improvement of the wide operating conditions of the compressed air energy storage system under environmental conditions and large changes in the gas storage pressure; when the operating mode is identified as the third operating mode, the compressor back pressure and power are adjusted according to the speed, the inlet guide vane angle and the outlet throttle valve opening, and the imbalance between the back pressure and the gas storage pressure is borne by the throttle valve to adjust the pipeline resistance characteristics, thereby relaxing the strict equation coupling constraints of the compression back pressure and the gas storage pressure, and expanding the coordinated control range of power tracking and back pressure regulation.

[0047] In an embodiment of the present application, the compressor back pressure and power are adjusted according to multiple factors such as the speed, the inlet guide vane angle and the outlet throttle valve opening, including: inputting multiple factors such as the speed, the inlet guide vane angle and the outlet throttle valve opening into a multi-control quantity collaborative control model, and the multi-control quantity collaborative control model outputs compressor back pressure and power increments; adjusting the compressor back pressure and power according to the compressor back pressure and power increments until the real-time back pressure and power of the compressor reach within a preset range of the target back pressure and power, and then adjusting the compressor back pressure and power according to the deviation between the real-time back pressure and the target back pressure.

[0048] Among them, the establishment of the multi-control variable collaborative control model is described in detail below and will not be repeated here; the preset range of the target back pressure is set according to the actual situation and is not specifically limited here.

[0049] It can be understood that the embodiment of the present application sets up a multi-control variable collaborative control model. By inputting multiple control variables such as the speed, inlet guide vane angle and outlet throttle valve opening into the multi-control variable collaborative control model, the multi-control variable collaborative control model can output the compressor back pressure and power increment. The compressor back pressure increment can be used to adjust the compressor back pressure. When it is detected that the real-time back pressure of the compressor reaches within the preset range of the target back pressure, the deviation between the real-time back pressure and the target back pressure is calculated, and the compressor back pressure is adjusted according to the deviation.

[0050] In the embodiment of the present application, the multi-control variable collaborative control model is:

[0051] J(x(k),U(k))=||αY(k+n|k)|| 2 +||βU(k)|| 2

[0052] Among them, the compressor back pressure increment prediction function ||αY(k+n|k)|| 2 , α corresponds to the output weight matrix, β corresponds to the control weight matrix, U(k) represents the vector sequence composed of n-step control quantities, and Y(k+n|k) corresponds to the sequence composed of n-step predicted outputs.

[0053] It can be understood that the embodiment of the present application establishes an n-step prediction equation for the system in a finite time domain. Starting from the current moment k, the system output is changed by adjusting the speed under the action of the n-step control sequence, and the cost function is established by using the output weight matrix α, the control weight matrix β, the vector sequence U(k) composed of the n-step control quantities, and the sequence Y(k+n|k) composed of the n-step prediction outputs. Minimizing the cost function will obtain the objective function.

[0054] In the embodiment of the present application, the multi-control variable cooperative control model includes multi-control variable constraints and compressor back pressure and power coupling constraints, wherein:

[0055] The constraints of multiple control variables are:

[0056]

[0057] in, and are the minimum speed and the maximum speed respectively, and are the minimum and maximum inlet guide vane angles, λ TVc and are the minimum and maximum throttle valve openings, and are the minimum and maximum flow rates respectively, the subscript i represents the number of compression stages,

[0058] If the operation mode is the second operation mode, the compressor back pressure and power coupling constraint condition is that the final stage compression back pressure must be kept equal to the gas storage pressure in real time, and the total compression power must be kept equal to the power command in real time:

[0059]

[0060] If the operation mode is the third operation mode, the compressor back pressure and power coupling constraint condition is:

[0061]

[0062] Among them, P c is the total compression power, Power command reference value, is the back pressure of the final compressor; p AS is the gas storage pressure, p TV It is the minimum pressure difference on both sides of the throttle valve.

[0063] It can be understood that the embodiment of the present application constrains the control quantity of each compression stage by forming multiple control quantity constraints through minimum speed and maximum speed, minimum and maximum inlet guide vane angles, minimum and maximum throttle valve openings, and minimum and maximum flow rates, wherein the flow rate refers to the amount of gas passing through per unit time; when it is identified that the operating mode is the second operating mode, the compressor back pressure and power coupling constraint is that the last stage compression back pressure must be kept equal to the gas storage pressure in real time, and the total power of the compressor matches the power instruction in real time; when it is identified that the operating mode is the third operating mode, the compressor back pressure coupling constraint is that the last stage compressor back pressure is greater than or equal to the sum of the minimum pressure difference on both sides of the throttle valve and the gas storage pressure.

[0064] According to the coordinated control method of compressor power tracking and backpressure regulation proposed in the embodiment of the present application, the operating mode and operating parameters of the compressor can be identified, and the target power tracking and backpressure regulation coordinated control method of the compressor can be determined according to the operating mode and operating parameters. Finally, the compressor backpressure and power are adjusted based on the target backpressure regulation method, thereby achieving flexible regulation of the compressor backpressure and power under a wide range of operating conditions in a compressed air energy storage power station under different operating modes.

[0065] The coordinated control method of compressor power tracking and back pressure regulation is further described below through a specific embodiment.

[0066] Figure 2 The schematic diagram of the adjustment mechanism of the compressor operating point under different control modes is as follows:

[0067] The actual operating point of the compressor is located at the intersection of the compressor performance curve and the pipe network characteristic curve. Changing the compressor characteristic curve or the pipe network characteristic curve can achieve the adjustment of the compressor operating conditions. Speed ​​control, inlet guide vane angle control and inlet throttling control achieve operating condition adjustment by moving the compressor characteristic curve, while outlet throttling control changes the pipe network characteristic curve by changing the pipeline resistance, thereby indirectly affecting the compression operating conditions.

[0068] The compressor of this embodiment involves control methods including speed control, inlet guide vane angle control and outlet throttling control. The specific technical solution process is as follows:

[0069] (1) Establish a method for adjusting compressor back pressure and power accordingly.

[0070] In the constant pressure operation mode, the back pressure of the final stage compression or the inlet pressure of the first stage turbine is always maintained at the design value, and the rated value of the back pressure of the final stage compression is generally taken as the upper limit of the gas storage pressure. A single outlet throttling method can meet the coordinated control requirements of compressor power tracking and back pressure regulation. By installing a throttle valve at the compressor outlet and adjusting the valve opening according to the change of gas storage pressure to achieve air pressure matching on both sides, constant pressure operation on the compression side can be achieved. Under single outlet throttling control, the air flow is uniquely determined by the valve opening.

[0071] In the sliding pressure mode, the compressor back pressure changes greatly with the gas storage pressure, and a single outlet throttling method cannot meet the flexible regulation of the compressor back pressure over a wide range. A composite control method of speed-inlet guide vane angle is adopted. Complementing the advantages of different adjustment methods can meet the improvement of the wide operating capacity of the compressed air energy storage system under environmental conditions and large changes in gas storage pressure. Since the regulating effect of the throttle valve on pressure and flow is not considered, this operating mode requires that the final stage compression back pressure is strictly equal to the gas storage pressure.

[0072] The pressure regulating operation mode combines the pressure regulating function of the throttle valve in the constant pressure mode with the efficiency advantage of the sliding pressure operation. It provides flow and pressure regulation by installing throttle valves at the final compression outlet and the first turbine inlet. The rated pressure ratio on both sides is set according to the sliding pressure mode. A multi-control quantity coupling control method of speed-inlet guide vane angle-outlet throttling is adopted. In the pressure regulating mode, the imbalance between the back pressure and the gas storage pressure is borne by the throttle valve to adjust the pipeline resistance characteristics, which relaxes the strict equation coupling constraints of the compression back pressure and the gas storage pressure, so the back pressure regulation range is significantly expanded. An embodiment is used to further illustrate the coordinated control method of compressor power tracking and back pressure regulation in the pressure regulating mode.

[0073] Step 1: According to the compressor pressure regulation operation mode, set the back pressure of the final compressor to track the real-time change curve of the gas storage pressure.

[0074] Step 2: Use sensors to read the current speed, inlet guide vane angle, throttle valve opening, and last-stage compressor back pressure and power command signal in real time.

[0075] Step 3: When the pressure ratio or flow rate is large, the fast response characteristics of speed control first reduce the compressor speed to quickly reduce the compressor back pressure and power to the expected value. High isentropic efficiency can be obtained only through speed regulation.

[0076] Step 4: Secondly, when the pressure ratio and flow rate drop to a certain critical value, it is necessary to adjust the inlet guide vane angle to obtain higher efficiency and achieve more precise control.

[0077] Step 5: When the pressure ratio stabilizes in a small range, the outlet throttling control can adjust the compressor flow without changing the speed to reduce the compressor's pressure ratio. Based on the current speed, the throttle valve opening is appropriately reduced.

[0078] Step 6: Through the closed-loop feedback system, the deviation between the real-time back pressure and the target back pressure is continuously monitored, the total compressed power is kept in real time with the deviation from the power command, and fine-tuned.

[0079] (2) Multi-control quantity collaborative control method:

[0080] In the sliding pressure and pressure regulating operation modes, there are multiple mutually coupled control quantities, and coordinated control is often required when a single adjustment method is difficult to achieve the expected effect. Among them, the speed, inlet guide vane angle and outlet throttle valve opening can be regarded as system adjustment quantities, and their control effects on compressed air flow, back pressure and power are mutually coupled. In this embodiment, multiple control quantities coordinately control the common goal of compressor back pressure and power, which is achieved by establishing a model predictive control strategy for speed-inlet guide vane angle-outlet throttling coordination. The specific technical solution is as follows:

[0081] Step 1: Establish a state space model of compressor back pressure and power-speed-inlet guide vane angle-outlet throttling. Discretize the state equation to obtain a discrete state equation. Each variable in the discrete state equation is a deviation near the rated value, which means that only a small signal disturbance needs to be superimposed on the initial value of the state variable to obtain the predicted change trajectory of the state variable. Select the compressor back pressure and power increment as the output equation.

[0082] Step 2: On this basis, establish the n-step prediction equation of the system in the finite time domain. Starting from the current k moment, by adjusting the speed, the system output will also change under the action of the n-step control sequence.

[0083] Step 3: Propose a cost function for the optimal control performance taking into account the response of compressor back pressure and power changes and the speed-inlet guide vane angle-outlet throttling. Consider the upper and lower limit constraints of the control quantity, as well as the coupling constraints of the back pressure, power and gas storage pressure of the last stage compressor. Establish an optimization model.

[0084] J(x(k),U(k))=||αY(k+n|k)|| 2 +||βU(k)|| 2 , (1)

[0085] Formula (1) is the cost function, and minimizing the cost function is the objective function. It corresponds to the compressor back pressure and power increment prediction function ||αY(k+n|k)|| 2 And the control function of the control quantity. Among them, α corresponds to the output weight matrix, and β corresponds to the control weight matrix. U(k) represents the vector sequence composed of n-step control quantities, and Y(k+n|k) corresponds to the sequence composed of n-step predicted outputs.

[0086]

[0087] In the formula, and are the minimum speed and the maximum speed respectively; and are the minimum and maximum inlet guide vane angles respectively; TVc and are the minimum and maximum throttle valve openings, respectively; and are the minimum and maximum flow rates respectively, and the subscript i represents the number of compression stages.

[0088] When sliding pressure operation is adopted, the back pressure of the final stage compression must be kept equal to the gas storage pressure in real time, and the coupling constraint is Equation 1. In the constant pressure and sliding pressure modes, the compressor outlet is equipped with a throttle valve, and the back pressure of the final stage compression is at least not lower than the gas storage pressure. The coupling constraint is Equation 2.

[0089]

[0090] In the formula, is the back pressure of the final compressor; p AS is the gas storage pressure; p TV It is the minimum pressure difference on both sides of the throttle valve.

[0091] Step 4: The weight α and the elements in the β matrix are coupled to each other and jointly determine the adjustment of the speed, throttle valve opening and inlet guide vane angle control quantity. Combined with the compressor back pressure and power coupling constraints, according to the multi-objective optimization method considering the cost function weight, based on the MPC control algorithm, the optimal control quantity is obtained to achieve coordinated control of multiple control quantities.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0093] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0094] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0095] It should be understood that the various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, the steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0096] A person of ordinary skill in the art may understand that all or part of the steps carried by the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the above-mentioned program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0097] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for coordinated control of compressor power tracking and back pressure regulation, characterized in that: The following steps are involved: Identify the operation mode and operation parameters of the compressor and convert them into a MIMO problem, wherein the operation mode includes the first to third modes, and the operation parameters include the rotation speed, the inlet guide vane angle, and the outlet throttle valve opening; Determine the coordinated control method of power tracking and target back pressure regulation of the compressor according to the operation mode and the operation parameters, wherein, if the operation mode is the first operation mode, the coordinated control method of power tracking and target back pressure regulation is: regulating the compressor back pressure and power according to the outlet throttle valve opening; if the operation mode is the second operation mode and the third operation mode, the coordinated control method of power tracking and target back pressure regulation is: regulating the compressor back pressure and power according to multiple of the speed, the inlet guide vane angle and the outlet throttle valve opening; The compressor back pressure and power are adjusted based on the power tracking and target back pressure adjustment collaborative control method.

2. The compressor power tracking and back pressure regulation coordinated control method according to claim 1 is characterized in that: The first operating mode is an operating mode in which the compressor back pressure remains unchanged, the second operating mode and the third operating mode are both operating modes in which the compressor back pressure changes, the last stage compression back pressure is equal to the gas storage pressure in the second operating mode, and the last stage compression back pressure is greater than or equal to the gas storage pressure in the third operating mode.

3. The compressor power tracking and back pressure regulation coordinated control method according to claim 1, characterized in that: If the operation mode is the first operation mode, the final stage compression back pressure or the first stage turbine inlet pressure is maintained at the design value.

4. The compressor power tracking and back pressure regulation coordinated control method according to claim 1, characterized in that: The step of adjusting the compressor back pressure and power according to the rotation speed, the inlet guide vane angle and the outlet throttle valve opening comprises: If the operation mode is the second operation mode, adjusting the compressor back pressure and power according to the rotation speed and the inlet guide vane angle; If the operation mode is the third operation mode, the compressor back pressure and power are adjusted according to the rotation speed, the inlet guide vane angle and the outlet throttle valve opening.

5. The compressor power tracking and back pressure regulation coordinated control method according to claim 4, characterized in that: The step of adjusting the compressor back pressure and power according to the rotation speed, the inlet guide vane angle and the outlet throttle valve opening comprises: Inputting the rotation speed, the inlet guide vane angle and the outlet throttle valve opening into a multi-control variable collaborative control model, the multi-control variable collaborative control model outputting the compressor back pressure increment; The compressor back pressure and power are adjusted according to the compressor power instruction and the back pressure increment until the real-time back pressure and power of the compressor reach within a preset range of the target back pressure and power, and the compressor back pressure and power are adjusted according to the deviation between the real-time back pressure and power and the target back pressure and power.

6. The compressor power tracking and back pressure regulation coordinated control method according to claim 5, characterized in that: The multi-control quantity coordinated control model is: J(x(k),U(k))=||aY(k+n∣k)|| 2 +||βU(k)|| 2 Among them, the compressor power command and back pressure increment prediction function ||αY(k+n|k)|| 2 , α corresponds to the output weight matrix, β corresponds to the control weight matrix, U(k) represents the vector sequence composed of n-step control quantities, and Y(k+n|k) corresponds to the sequence composed of n-step predicted outputs.

7. The compressor power tracking and back pressure regulation coordinated control method according to claim 6, characterized in that: The multi-control variable cooperative control model includes multi-control variable constraints and compressor power and back pressure coupling constraints, wherein: The multi-control quantity constraint conditions are: in, and are the minimum speed and the maximum speed respectively, and are the minimum and maximum inlet guide vane angles, λ TVc and are the minimum and maximum throttle valve openings, and are the minimum and maximum flow rates respectively, the subscript i represents the number of compression stages, If the operation mode is the second operation mode, the compressor power and back pressure coupling constraint condition is that the total compression power is kept equal to the power instruction in real time, and the final stage compression back pressure needs to be kept equal to the gas storage pressure in real time: If the operation mode is the third operation mode, the compressor back pressure and power coupling constraint condition is: Among them, P c is the total compression power, Power command reference value, is the back pressure of the final compressor; p AS is the gas storage pressure, p tV It is the minimum pressure difference on both sides of the throttle valve.

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