Networked control water supply system stability analysis method, equipment and storage medium

Abstract

The invention discloses a networked control water supply system stability analysis method, and the method comprises the steps: building a control object model of a nuclear power plant water supply system, and obtaining the time delay in the networked control of the nuclear power plant water supply system; obtaining a discrete state space expression corresponding to the networked control of the water supply system of the nuclear power station based on the operation characteristics of the water supply system of the nuclear power station; based on the discrete state space expression, obtaining a z transfer function corresponding to the networked control of the nuclear power plant water supply system; and obtaining the networked control stability of the water supply system of the nuclear power station based on the maximum zero pole distribution of the z transfer function. The invention further discloses networked control water supply system stability analysis equipment and a corresponding storage medium. According to the stability analysis method for the networked control water supply system provided by the embodiment of the invention, the networked control stability of the nuclear power plant water supply system can be judged, and the design of the high-safety and high-reliability networked control system of the nuclear power plant is guided.

Description

Technical Field

[0001] The present application relates to the field of industrial control technology, and more specifically, to a stability analysis method, device and storage medium for a networked control water supply system. Background Art

[0002] The importance of nuclear power plant safety is self-evident. If there is a problem with the control system of a nuclear power plant, it will not only threaten the safety of the nuclear power plant itself, but also affect the safety of the surrounding environment, leading to serious consequences. Therefore, it is extremely important to ensure the safety of the control system of a nuclear power plant. To ensure the safety of a nuclear power plant, the focus is on improving the control system of the nuclear power plant, strengthening safety supervision and emergency measures, so as to prevent possible accidents.

[0003] The network control of nuclear power plants is a feedback control system composed of networks. It has the advantages of simple wiring, convenient maintenance, easy expansion, high reliability and resource sharing. However, it also has problems such as delay, packet loss and timing disorder during data transmission. In addition, the object analyzed by network control is not only an independent control process, but also a generalized control object with network characteristics. Therefore, how to analyze the stability of the network control system of the water supply system is an urgent problem to be solved. Summary of the invention

[0004] In response to at least one defect or improvement need in the prior art, the present invention provides a networked control water supply system stability analysis method, device and storage medium, which will solve at least one of the problems existing in the above-mentioned background technology.

[0005] To achieve the above object, according to a first aspect of the present invention, a method for analyzing the stability of a networked controlled water supply system is provided, the method comprising:

[0006] Establish the control object model of the nuclear power plant water supply system and obtain the time delay in the networked control of the nuclear power plant water supply system;

[0007] Based on the operation characteristics of the water supply system of nuclear power plants, the discrete state space expression corresponding to the networked control of the water supply system of nuclear power plants is obtained;

[0008] Based on the discrete state space expression, obtaining the z transfer function corresponding to the networked control of the nuclear power plant water supply system;

[0009] Based on the maximum zero-pole distribution of the z transfer function, the networked control stability of the nuclear power plant water supply system is obtained.

[0010] Furthermore, in the above-mentioned networked control water supply system stability analysis method, the control object model of the nuclear power plant water supply system specifically includes:

[0011] x(t)=A cx(t)+B c u(t)

[0012] y(t)=C c x(t)

[0013] Among them, x(t), u(t), and y(t) are the state quantity, control quantity, and output quantity of the nuclear power plant water supply system, respectively.

[0014] Furthermore, in the above-mentioned networked control water supply system stability analysis method, the time delay in the networked control of the nuclear power plant water supply system includes the time delay from the sensor to the controller in the system. Delay from controller to actuator and the controller computation delay The total delay is

[0015] Furthermore, in the above-mentioned networked control water supply system stability analysis method, the operation characteristics of the water supply system of the nuclear power plant specifically include:

[0016] The delay is within the preset threshold range, τ k <h min ;

[0017] Time-varying sampling period T k =h k +τ k , where h k It is time-varying, and the sampling period ranges from T k ∈[T min ,T max ];

[0018] h k The nominal value of h0 is h k =h0+Δ k , where Δ k is the uncertain part of the variable sampling period;

[0019] The sampling time is t k , then the sampling period is T k =t k+1 -t k .

[0020] Furthermore, the above-mentioned networked control water supply system stability analysis method, based on the operation characteristics of the nuclear power plant water supply system, obtains the discrete state space expression corresponding to the networked control of the nuclear power plant water supply system, specifically including:

[0021] The control input quantity u(t-τ k ) at t∈[t k ,t k+τ) and t∈[t k +τ,t k+1 ) remains unchanged,

[0022]

[0023] Get the new state matrix

[0024]

[0025] Get new input matrix

[0026]

[0027] Get the new output matrix

[0028] C d =[C c 0]

[0029] Get the new direct transfer matrix

[0030]

[0031] Where β is a pre-set value

[0032] Get the new other matrix

[0033]

[0034] Introduce the augmented variable z(k)=[x T (k),u T (k-1)] T ,have

[0035] z(k+1)=Φ(h k )z(k)+Γ(h k )u(k)

[0036] in:

[0037]

[0038] The discrete state space expression corresponding to the networked control of the nuclear power plant water supply system is obtained as follows:

[0039]

[0040] Furthermore, in the above-mentioned networked control water supply system stability analysis method, the z transfer function corresponding to the networked control of the nuclear power plant water supply system is:

[0041] G(z)=C d (zI-(A d +D d F kE1)) -1 (B d +D d F k E2).

[0042] Furthermore, the above-mentioned networked control water supply system stability analysis method, based on the maximum zero-pole distribution of the z transfer function, obtains the networked control stability of the nuclear power plant water supply system, specifically including:

[0043] Analyze the maximum zero-pole distribution of G(z) and obtain the pole with the largest absolute value λ max (G(z)), then the stability is

[0044] γ=1-λ max (G(z))

[0045] The closer γ is to 1, the more stable the system is.

[0046] According to the second aspect of the present invention, there is also provided a networked control water supply system stability analysis device, which includes at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of any one of the above-mentioned methods.

[0047] According to the third aspect of the present invention, a storage medium is also provided, which stores a computer program that can be executed by a network-controlled water supply system stability analysis device. When the computer program runs on the network-controlled water supply system stability analysis device, the network-controlled water supply system stability analysis device executes the steps of any one of the above-mentioned methods.

[0048] According to a fourth aspect of the present invention, there is also provided a computer program product, comprising a computer program, characterized in that when the computer program is executed by a processor, the steps of any one of the above methods are implemented.

[0049] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0050] The networked control water supply system stability analysis method provided by the present invention converts the uncertainty in the network into the uncertainty of system parameters, constructs a networked uncertainty control discrete system, can judge the stability of the networked control of the water supply system of a nuclear power plant, and guide the design of a high-safety and high-reliability networked control system for a nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 A flow chart of a networked control water supply system stability analysis method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0055] Figure 1 A flow chart of a networked control water supply system stability analysis method provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the networked control water supply system stability analysis method provided in the embodiment of the present application includes:

[0056] 101 Establish the control object model of the nuclear power plant water supply system and obtain the time delay in the networked control of the nuclear power plant water supply system;

[0057] 102 Based on the operation characteristics of the water supply system of the nuclear power plant, obtain the discrete state space expression corresponding to the networked control of the water supply system of the nuclear power plant;

[0058] 103 Based on the discrete state space expression, a z transfer function corresponding to the networked control of the nuclear power plant water supply system is obtained;

[0059] 104 Based on the maximum zero-pole distribution of the z transfer function, the networked control stability of the nuclear power plant water supply system is obtained.

[0060] Specifically, the nuclear water supply system is taken as the research object, and a mathematical model of the dynamic characteristics of the water supply system is established. The model includes the state variables of the system, the control input and the basis for subsequent output analysis. The control object model can accurately describe the dynamic behavior of the power station reflection system, so as to analyze the impact of network characteristics such as delay on control performance.

[0061] The key delay data in the nuclear feedwater system is obtained through the networked control system, including the delays in each stage such as sensor to controller, controller to actuator, and controller internal calculation. Since the delay will affect the delay acquisition response and stability of the system power station, the unified speed modeling is considered for each delay delay for subsequent expression in the state space. To improve the accuracy of the analysis, the short delay case is only applicable to the operation control environment of conventional nuclear.

[0062] Based on the acquired water supply system, the discrete state space expression of the networked control system is constructed by taking into account the time delay information and the control object model. This expression realizes the characteristics of the networked control system under the conditions of uncertainty and time variation, including the system's state matrix, input matrix, output matrix, and direct transfer matrix, etc., and uses mathematical models to accurately express the system behavior. The discrete state space expression can better characterize the impact of the control network delay on the dynamic characteristics of the object control.

[0063] Based on the discrete state space expression, the z transfer function of the networked control system is obtained through mathematical transformation. The z transfer function is used to describe the dynamic relationship between the input and output of the system and analyze the stability and dynamic response characteristics of the system in the frequency domain. The calculation results of the transfer function can be used for the subsequent stability analysis of the zero-pole distribution, which helps to judge the overall performance of the water supply system.

[0064] By analyzing the maximum zero-pole distribution of the z transfer function, the stability of the networked control system is obtained. The closer the absolute value of the maximum zero-pole is to 1, the faster the system can recover stability after being disturbed. Zero-pole distribution analysis provides a quantitative analysis method for judging the stability of the control system, further optimizing the system design, and improving the stability and response performance of the nuclear power plant water supply system under networked control conditions.

[0065] The networked control water supply system stability analysis method provided in the embodiment of the present application, by converting the uncertainty in the network into the uncertainty of the system parameters, constructs a networked uncertainty control discrete system, can determine the stability of the networked control of the water supply system of a nuclear power plant, and guide the design of a high-safety and high-reliability networked control system for a nuclear power plant.

[0066] Optionally, in the networked control water supply system stability analysis method provided in the embodiment of the present application, the control object model of the nuclear power plant water supply system specifically includes:

[0067] x(t)=A c x(t)+B c u(t)

[0068] y(t)=C c x(t)

[0069] Among them, x(t), u(t), and y(t) are the state quantity, control quantity, and output quantity of the nuclear power plant water supply system, respectively.

[0070] Optionally, in the networked control water supply system stability analysis method provided in the embodiment of the present application, the time delay in the networked control of the water supply system of the nuclear power plant includes the time delay from the sensor to the controller in the system. Delay from controller to actuator and the controller computation delay The total delay is

[0071] Optionally, in the networked control water supply system stability analysis method provided in the embodiment of the present application, the operation characteristics of the water supply system of the nuclear power plant specifically include:

[0072] The delay is within the preset threshold range, τ k <h min ;

[0073] Time-varying sampling period T k =h k +τ k , where h k It is time-varying, and the sampling period ranges from T k ∈[T min ,T max ];

[0074] h k The nominal value of h0 is h k =h0+Δ k , where Δ k is the uncertain part of the variable sampling period;

[0075] The sampling time is t k , then the sampling period is T k =t k+1 -t k .

[0076] Optionally, the networked control water supply system stability analysis method provided in the embodiment of the present application, based on the operation characteristics of the water supply system of the nuclear power plant, obtains the discrete state space expression corresponding to the networked control of the water supply system of the nuclear power plant, specifically including:

[0077] The control input quantity u(t-τk ) at t∈[t k ,t k +τ) and t∈[t k +τ,t k+1 ) remains unchanged,

[0078]

[0079] Get the new state matrix

[0080]

[0081] Get new input matrix

[0082]

[0083] Get the new output matrix

[0084] C d =[C c 0]

[0085] Get the new direct transfer matrix

[0086]

[0087] Where β is a pre-set value

[0088] Get the new other matrix

[0089]

[0090] Introduce the augmented variable z(k)=[x T (k),u T (k-1)] T ,have

[0091] z(k+1)=Φ(h k )z(k)+Γ(h k )u(k)

[0092] in:

[0093]

[0094] The discrete state space expression corresponding to the networked control of the nuclear power plant water supply system is obtained as follows:

[0095]

[0096] Optionally, in the networked control water supply system stability analysis method provided in the embodiment of the present application, the z transfer function corresponding to the networked control of the water supply system of the nuclear power plant is:

[0097] G(z)=Cd (zI-(A d +D d F k E1)) -1 (B d +D d F k E2).

[0098] Optionally, the networked control water supply system stability analysis method provided in the embodiment of the present application, the obtaining of the networked control stability of the water supply system of the nuclear power plant based on the maximum zero-pole distribution of the z transfer function, specifically includes:

[0099] Analyze the maximum zero-pole distribution of G(z) and obtain the pole with the largest absolute value λ max (G(z)), then the stability is

[0100] γ=1-λ max (G(z))

[0101] The closer γ is to 1, the more stable the system is.

[0102] Specifically, determine the stability of networked control of the nuclear power plant’s water supply system.

[0103]

[0104] The closer γ is to 1, the more stable the system is, and the faster it can converge to stability after being disturbed.

[0105] In one embodiment, based on the networked control water supply system stability analysis method provided in the embodiment of the present application, taking the water supply system of a nuclear power plant of a marine transport vehicle as an example, the following steps are included:

[0106] Establish the control object model of the nuclear power plant water supply system.

[0107]

[0108] Analysis of the delay in the networked control of the nuclear power plant water supply system shows that there are three main aspects of delay, namely the delay from the sensor to the controller in the system. Controller to actuator delay and the calculation delay of the controller Discuss and remember:

[0109]

[0110] Considering the actual situation of nuclear power plant system operation control, it has the following characteristics:

[0111] 1) Only consider the case of short delay, that is, τ k <hmin ;

[0112] 2) Time-varying sampling period T k =h k +τ k , due to h k is time-varying and bounded, then the sampling period of the networked control system is also time-varying and bounded, that is, T k ∈[T min ,T max ];

[0113] 3)h k The nominal value of is denoted as h0. Then h k =h0+Δ k , Δ k is the uncertain part of the variable sampling period;

[0114] 4) The sensor in the system is time-driven, and its sampling time is t k , its sampling period is T k =t k+1 -t k , the controller and actuator are event-driven.

[0115]

[0116] Since the current nuclear power plant system actuator has the characteristics of zero-order hold, the control input u(t-τ k ) does not change with the sensor at sampling time t k Synchronous changes, and at t∈[t k ,t k +τ) and t∈[t k +τ,t k+1 ) remains unchanged, that is,

[0117]

[0118] Discretize the network of the nuclear power plant water supply system and obtain a new state matrix

[0119]

[0120] Get the new input matrix

[0121]

[0122] Get the new output matrix

[0123] C d =[C c 0]=[0 1 0]

[0124] Get the new direct transfer matrix

[0125]

[0126] Wherein: β is a value to be determined and can be set according to actual conditions.

[0127] Get the new other matrix

[0128]

[0129] Introduce the augmented variable z(k)=[x T (k),u T (k-1)] T , which can be written as:

[0130] z(k+1)=Φ(h k )z(k)+Γ(h k )u(k)

[0131] in:

[0132]

[0133] The discrete state space expression corresponding to the networked control of the nuclear power plant water supply system is obtained as follows:

[0134]

[0135] The z transfer function expression corresponding to the networked control of the nuclear power plant water supply system is obtained as follows:

[0136]

[0137] Analyze the maximum zero-pole distribution of G(z) and obtain the pole with the largest absolute value λ max (G(z))=0.8902, then the degree of stability is:

[0138] γ=1-λ max (G(z))=0.1098

[0139] Determine the stability of networked control of nuclear power plant water supply system.

[0140] γ=1-λ max (G(z))=0.1098>0

[0141] It means that the system is stable and can converge to stability after being disturbed.

[0142] The present application also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the above method are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0143] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0144] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0145] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0146] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0147] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0148] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program code.

[0149] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable memory, which can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0150] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0151] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0152] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A networked control water supply system stability analysis method, characterized in that: include: Establish the control object model of the nuclear power plant water supply system and obtain the time delay in the networked control of the nuclear power plant water supply system; Based on the operation characteristics of the water supply system of nuclear power plants, the discrete state space expression corresponding to the networked control of the water supply system of nuclear power plants is obtained; Based on the discrete state space expression, obtaining the z transfer function corresponding to the networked control of the nuclear power plant water supply system; Based on the maximum zero-pole distribution of the z transfer function, the networked control stability of the nuclear power plant water supply system is obtained.

2. The networked control water supply system stability analysis method according to claim 1, characterized in that: The control object model of the nuclear power plant water supply system specifically includes: x(t)=A c x(t)+B c u(t) y(t)=C c x(t) Among them, x(t), u(t), and y(t) are the state quantity, control quantity, and output quantity of the nuclear power plant water supply system, respectively.

3. The stability analysis method of a networked controlled water supply system according to claim 2, characterized in that: The time delay in the networked control of the nuclear power plant water supply system includes the time delay from the sensor to the controller in the system. Delay from controller to actuator and the controller computation delay The total delay is 4. The method for analyzing the stability of a networked controlled water supply system according to claim 3, characterized in that: The operation characteristics of the water supply system of the nuclear power plant specifically include: The delay is within the preset threshold range, τ k <h min ; Time-varying sampling period T k =h k +τ k , where h k It is time-varying, and the sampling period ranges from T k ∈[T min ,T max ]; h k The nominal value of h0 is h k =h0+Δ k , where Δ k is the uncertain part of the variable sampling period; The sampling time is t k , then the sampling period is T k =t k+1 -t k .

5. The method for analyzing the stability of a networked controlled water supply system according to claim 4, characterized in that: The method of obtaining the discrete state space expression corresponding to the networked control of the water supply system of the nuclear power plant based on the operation characteristics of the water supply system of the nuclear power plant specifically includes: The control input quantity u(t-τ k ) at t∈[t k ,t k +τ) and t∈[t k +τ,t k+1 ) remains unchanged, Get the new state matrix Get new input matrix Get the new output matrix C d =[C c 0] Get the new direct transfer matrix Where β is a pre-set value Get the new other matrix Introduce the augmented variable z(k)=[x T (k),u T (k-1)] T ,have z(k+1)=Φ(h k )z(k)+Γ(h k )u(k) in: A d +D d F k E1 The discrete state space expression corresponding to the networked control of the nuclear power plant water supply system is obtained as follows:

6. The method for analyzing the stability of a networked controlled water supply system according to claim 5, characterized in that: The z transfer function corresponding to the networked control of the nuclear power plant water supply system is: G(z)=C d (zI-(A d +D d F k E1)) -1 (B d +D d F k E2)。 7. The method for analyzing the stability of a networked controlled water supply system according to claim 6, characterized in that: The obtaining of the networked control stability of the water supply system of the nuclear power plant based on the maximum zero-pole distribution of the z transfer function specifically includes: Analyze the maximum zero-pole distribution of G(z) and obtain the pole with the largest absolute value λ max (G(z)), then the stability is γ=1-λ max (G(z)) The closer γ is to 1, the more stable the system is.

8. A networked control water supply system stability analysis device, characterized in that: The method comprises at least one processing unit and at least one storage unit, wherein the storage unit stores a computer program, and when the computer program is executed by the processing unit, the processing unit executes the steps of the method according to any one of claims 1 to 7.

9. A storage medium, characterized in that: It stores a computer program that can be executed by a network-controlled water supply system stability analysis device. When the computer program runs on the network-controlled water supply system stability analysis device, the network-controlled water supply system stability analysis device executes the steps of the method described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the networked control water supply system stability analysis method as claimed in any one of claims 1 to 7 are implemented.

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