An automatic control system information network static model and a fault analysis method thereof

Abstract

The application provides an automatic control system information network static model and a fault analysis method thereof, and belongs to the field of power information physical systems and power system automation. The static model comprises an information network element layer, a communication link layer and a network element layer. The information network element layer comprises a measurement element unit, an information transmission path unit, an information calculation and processing unit and an execution element unit, and is used for showing the information flow transmission process of the automatic control system. The communication link layer is used for representing a communication link submodel corresponding to any submodel in the information network element layer. The network element layer is used for representing a network element submodel corresponding to any communication link submodel. The application realizes the association of the information flow of the automatic control system service model and the actual system communication link and element, can quickly locate the propagation path of the information network exception and fault in the power automatic control system, and facilitates the fault analysis of the information physical coupling.

Description

Technical Field

[0001] The present invention belongs to the field of electric power information-physical systems and electric power system automation, and in particular relates to an automatic control system information network static model and a fault analysis method thereof. Background Art

[0002] To achieve real-time perception, dynamic control, and intelligent services for modern power systems, more advanced computing, communication, and control components are tightly coupled with the traditional physical systems of power systems, forming cyber-physical systems. Closed-loop automatic control systems are hosted on the power communication system. As a critical component of the power secondary system, failures in automatic control systems can affect the physical power grid through cyber-physical coupling. Currently, barriers exist between the power system's information network monitoring system and the power automatic control system, making it difficult to directly analyze the impact of information disturbances and failures on specific automatic control system services. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention proposes a static model of an automatic control system information network and a fault analysis method therefor. This method correlates the information flows of the automatic control system's business model with the actual system communication links and components. Based on this correlation model, it can quickly locate the propagation paths of information network anomalies and faults in the power automation system, facilitating cyber-physical coupling fault analysis.

[0004] The embodiment of the present invention proposes an automatic control system information network static model, including: an information network component layer, a communication link layer, and a network component layer;

[0005] The information network element layer includes a measurement element unit composed of multiple measurement element sub-models, an information transmission path unit composed of information transmission path sub-models connecting each measurement element sub-model, an information calculation and processing unit, and an execution element unit composed of multiple execution element sub-models. The information network element layer is used to display the information flow transmission process of the automatic control system, including the interaction between the automatic control system and the physical power grid.

[0006] The communication link layer is used to represent the communication link sub-model corresponding to any sub-model in the information network element layer;

[0007] The network element layer is used to represent the network element sub-model corresponding to any communication link sub-model in the communication link layer; the network element sub-model is used to indicate the communication network elements included in the corresponding communication link.

[0008] In a specific embodiment of the present invention, the measuring element unit is used to obtain the required physical quantity and convert it into the input of the information network; the information transmission path unit is used to transmit various types of data; the information calculation and processing unit is used to generate control instructions of the system based on the set logic; and the execution element unit is used to convert the control instructions carried by the information network information into actual physical quantities.

[0009] In a specific embodiment of the present invention, the static model construction method includes:

[0010] First, based on the coupling relationship between the information and physical systems, the information network component layer is constructed. The information network component layer includes: physical quantity acquisition link, transmission path link, calculation and analysis link, downlink path link and instruction execution link. The information network component layer also establishes the information processing process function carried by each link. Secondly, based on the virtual channel of the power grid communication system, the communication link layer is established, including: link model carrying information, primary and backup routes and link status. Finally, based on the physical component model of the communication network, it is associated with the communication link.

[0011] In a specific embodiment of the present invention, the step of constructing the information network component layer includes:

[0012] 1) Construct the measurement component sub-model;

[0013] For any measuring element n m , whose input is the state of the physical grid Output is the collection of system status F m It represents the measurement matrix, which represents the mapping of the actual signal through the acquisition process;

[0014] The sub-model expression corresponding to the measurement element is as follows:

[0015]

[0016] 2) Construct the executive component sub-model;

[0017] For any execution node n a , whose input is the control instruction of the upper branch Output is the receiving instruction of the actuator F a represents the execution matrix, which represents the mapping of control signals through the execution process;

[0018] The sub-model expression corresponding to this execution node is as follows:

[0019]

[0020] 3) Construct the information transmission pathway sub-model;

[0021] For any information transmission path T k , respectively, using column vectors and Represents the data of its input node and output node, then the information transmission path sub-model expression is as follows:

[0022]

[0023] Where, the matrix M k is a square matrix whose order is the same as the vector and same;

[0024] 4) Construct information computing and processing units;

[0025] For any business, use column vector and The expressions representing the data, information calculation and processing units of its input nodes and output nodes are as follows:

[0026]

[0027] Where, F c Represents the mapping function corresponding to this link.

[0028] In a specific embodiment of the present invention, it also includes:

[0029] When the measurement signal is collected without error, F m The element of F is 1; when the control signal is executed without error, a The element of M is 1; when the information transmission path is not disturbed, k is an identity matrix.

[0030] In a specific embodiment of the present invention, establishing a communication link layer includes:

[0031] 1) Constructing a data link set associated with information elements;

[0032] The communication link layer is a collection of different data links from the start information element to the end information element, expressed as follows:

[0033]

[0034] Among them, Lk ij represents the set of communication links from information element i to information element j, represents the kth communication link from information element i to information element j, where k = 1, 2, ..., N, and there are N communication link paths in the set;

[0035] 2) Obtain the status of the communication link;

[0036] For each communication link Establish its state bit State respectively l and status flag P l , where State l =0, when interrupted, State l =-1, State when bit error occurs l =1.

[0037] In a specific embodiment of the present invention, it also includes:

[0038] When State l =1, the bit error rate of the communication link is recorded.

[0039] In a specific embodiment of the present invention, associating the physical component model based on the communication network with the communication link includes:

[0040] 1) For any communication link Let the associated set be:

[0041]

[0042] in, is the mth communication channel of the communication link k between information element i and information element j, and M is the total number of communication channels;

[0043] 2) Obtain the status of the communication channel;

[0044] For any communication channel Get its state bit State c and status flag P c , where State is normal c =0, when interrupted, State c =-1, State when bit error occurs c =1.

[0045] In a specific embodiment of the present invention, it also includes:

[0046] When State c =1, record the bit error rate of the channel.

[0047] The embodiment of the present invention further proposes a fault analysis method based on the above static model, including:

[0048] 1) Establish the propagation path of the impact of component failure at each level;

[0049] For any communication channel and its abnormal state According to the communication channel and communication link association, the communication link between communication elements i and j Status The calculation expression is as follows:

[0050]

[0051] Where η m,k is the influence weight of the mth communication network element on the kth path;

[0052] The fault impact is propagated to the information network element layer in a weighted manner according to the status of the communication link, namely:

[0053]

[0054] Where, ζ k LK is the kth path pair ij The impact weight of

[0055] 2) Analysis of the impact of information components on automatic control systems;

[0056] For any information element LK ij ,The impact of the automatic control system is based on the ,cyber-physical coupling model.,First, the impact of the abnormal information component on the ,information volume is analyzed., and then the impact of the information volume on the ,key physical indicators of the physical system is analyzed.

[0057]

[0058] Among them, λ p is the set physical quantity, s c is the amount of information in the automatic control system; f is the fault impact equation of information-physical coupling, which is the product of the sensitivity of information elements to information flow and the sensitivity of information flow to physical quantities.

[0059] Features and beneficial effects of the present invention:

[0060] The present invention is an improvement on the information flow network model based on a directed graph. While retaining the basic architecture of the information network element model, it adds a measurement element sub-model and an execution element sub-model, so that the interaction path between the information network and the physical power grid is clear, which facilitates the location of faults and the whole process analysis; in addition, the information network element is used as the business layer of the information flow, and the communication link layer and the network element layer are expanded downward, so that the information network model and the power system communication system link and the actual communication network element are associated. Compared with a single information network element model, it is more in line with the actual power system and breaks down the barriers to its application in the actual power system.

[0061] 1) The static model construction of the present invention associates the automatic control system business flow with the communication link and the communication system components, which facilitates the analysis of the propagation path of faults and disturbances occurring at the information network component layer to the automatic control system business, and facilitates the quantitative analysis of faults in cyber-physical fusion.

[0062] 2) The present invention breaks down the barriers between information networks and automatic control system services, helping the automatic control system analyze the impact of communication system failures on its services and effectively improving the resilience of the power secondary system.

[0063] 3) The information network static model constructed by the present invention is applicable to various automatic control services, such as automatic power generation control, automatic voltage control, etc., and can be used as an advanced application to assist the construction and safe operation of such systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a structural diagram of a static model of an automatic control system information network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0065] The present invention proposes an automatic control system information network static model and a fault analysis method, which are further described below with reference to specific embodiments of the drawings.

[0066] The embodiment of the present invention proposes a static model of an automatic control system information network, the structure of which is as follows: Figure 1 As shown, it includes: information network element layer, communication link layer, and network element layer.

[0067] The information network element layer includes a measurement element unit composed of multiple measurement element sub-models, an information transmission path unit composed of an information transmission path sub-model connecting each measurement element sub-model, an information calculation and processing unit, and an execution element unit composed of multiple execution element sub-models. The information network element layer is used to display the information flow transmission process of the automatic control system, including the interaction between the automatic control system and the physical power grid.

[0068] Furthermore, the measuring element unit is used to obtain the required physical quantity and convert it into the input of the information network; the information transmission path unit is used to transmit various types of data, such as the transmission of acquisition, control and other data between upper and lower units; the information calculation and processing unit is used to generate system control instructions based on the set logic; the execution element unit is used to convert the control instructions carried by the information network information into actual physical quantities.

[0069] The communication link layer is used to represent the specific communication link sub-model corresponding to any sub-model in the information network element layer. Figure 1The communication link layer in the figure shows the communication link sub-model corresponding to an information transmission path sub-model in the information network component layer. In addition, the communication links corresponding to other sub-models in the information network component layer can also be represented in the communication link layer. Figure 1 As shown in FIG, the information transmission path sub-model corresponds to the communication link sub-model at the communication link layer, indicating that the information transmission path may include multiple communication links. Specifically, the information transmission path, in this embodiment, is recorded as uplink path 3 at the information network element layer, and includes four communication link sub-models at the communication link layer (respectively Figure 1 As shown in the communication link 1, communication link 2 is connected to communication link 2-1, communication link 2 is connected to communication link 2-2, and communication link 2 is connected to communication link 2-3), wherein the components within each link are different, but the starting point and end point are the same. In this embodiment, the starting point of the four communication links is the measurement node, and the end point is the Control Center. The control center here is a generalized representation of the information calculation and processing unit of the information network element layer.

[0070] The network element layer is used to represent the network element sub-model corresponding to any communication link sub-model in the communication link layer. The network element sub-model is used to indicate that the corresponding communication link may include multiple specific communication network elements, such as routers, optical fibers, etc. Figure 1 The network element layer in Figure 1 shows the network element sub-model corresponding to the communication link 2-3 in the communication link layer. Figure 1 As shown, the network element sub-model shows that the link is composed of three routers and five actual network transmission lines.

[0071] Furthermore, this embodiment also proposes a method for constructing a static model of the information network of the automatic control system. The method first constructs the information network component layer of the closed-loop control system based on the information-physical system coupling relationship. The layer specifically includes five parts: physical quantity acquisition link, transmission path link, calculation and analysis link, downlink path link, and instruction execution link. A function for the information processing process carried by each part is established. Secondly, a communication link layer is established based on the virtual channel of the power grid communication system, including an abstract construction of a specific link model carrying information, primary and backup routes, and link status. Finally, the specific physical component model of the communication network is associated with the communication link. The method specifically includes the following steps:

[0072] 1) Construct the information network component layer of the cyber-physical coupled automatic control system, specifically including:

[0073] 1-1) Construct the measurement component sub-model.

[0074] In this embodiment, the measurement element sub-model serves as the information source of the closed-loop control system and is the core of the interaction from physical quantity to information. m , whose input is the state of the physical grid Output is the collection of system status F m Represents the measurement matrix, which represents the mapping of the actual signal through the acquisition process, in which there may be errors, delays, etc. If there is no error F m The element of is 1. The sub-model expression corresponding to the measurement element is as follows:

[0075]

[0076] 1-2) Construct the executive component sub-model.

[0077] In this embodiment, the execution element is the output end of the closed-loop control system and the core of the information to physical power grid operation. a , whose input is the control instruction of the upper branch Output is the receiving instruction of the actuator F a Represents the execution matrix, which represents the mapping of the control signal through the execution process, in which there may be misoperation, error code, etc. If there is no error F a The element of is 1. The sub-model expression corresponding to this execution node is as follows:

[0078]

[0079] 1-3) Construct the information transmission path sub-model.

[0080] In this embodiment, most information transmission paths can be represented as a directed transmission path with a path gain of 1. When there is a disturbance, the information carried by it may experience multiple types of changes such as delay and error. Therefore, for any information transmission path T k , respectively, using column vectors and Represents the data of its input nodes and output nodes, then the information transmission path sub-model can be described as:

[0081]

[0082] Where, the matrix M k is a square matrix whose order is the same as the vector and Same. When no information disturbance occurs, M k It can be regarded as an identity matrix; when there is a perturbation, its matrix elements will undergo a correction related to the perturbation.

[0083] 1-4) Build information computing and processing units.

[0084] In this embodiment, the information calculation and processing unit is the analysis and calculation link of the information flow, which is mapped into output data through a specific mapping function (such as control instruction calculation and physical component operation). c There is only one, using column vectors and The data, information calculation and processing units representing its input nodes and output nodes can be described as:

[0085]

[0086] Where, F c Represents the mapping function corresponding to this link. For different closed-loop control models and automatic control software, it is given according to actual business. For example, the proportional-integral control in frequency control is not necessarily a linear function.

[0087] 2) Build the communication link layer, including:

[0088] 2-1) Construct a data link set associated with information components.

[0089] In this embodiment, for different data types (such as frequency acquisition, capacitor switching signals, etc.), the corresponding number of propagation paths in the link is different. In addition, the data will pass through different intermediate stations during the transmission process between the starting station and the ending station. Therefore, the communication link layer can be modeled as a process from the starting information element to the ending information element (such as Figure 1 The collection of different data links in the data link from the measurement node to the control center is as follows:

[0090]

[0091] Among them, Lk ij represents the set of communication links from information element i to information element j, The kth communication link from information element i to information element j is represented by k = 1, 2, ..., N. There are N specific communication link paths in this set (N ≥ 1). It should be noted that the specific number N of communication links between different information elements i and j is different and is determined by different communication networks.

[0092] 2-2) Obtaining the status of the communication link;

[0093] In this embodiment, for each specific communication link Establish its state bit State respectively l and status flag P l, corresponding to normal / different abnormalities (normal: State l =0; Interrupt State l =-1; Error State l =1); and the degree of abnormality (only bit errors are effective, and the bit error rate is recorded).

[0094] 3) Based on the results of steps 1) and 2), the communication network element is associated with the communication link; the specific steps are as follows:

[0095] 3-1) Communication network elements are the actual physical components of the power grid secondary system, such as routers and optical fibers. There is a specific relationship between their elements and the communication link layer. For a single communication link Its associated communication network element set is:

[0096]

[0097] in, is the mth channel of the communication link k between nodes i and j, and M is the total number of signals. The value of M is different.

[0098] 3-2) Obtain the status of the communication network element; for a certain actual communication network element Its status bit comes from the collected information of the actual power grid secondary monitoring, which is similar to the status definition of the communication link. c and status flag P c , corresponding to normal / different abnormalities (normal: State c =0; Interrupt State c =-1; Error State c =1); and the degree of abnormality (only bit errors are effective, and the bit error rate is recorded).

[0099] Furthermore, this embodiment also proposes a fault analysis method based on the above-mentioned automatic control system information network static model, including:

[0100] 1) Establish the propagation path of the impact of component failure at each level.

[0101] In this embodiment, for any communication network element and its abnormal state According to the association between the communication network elements and the communication links, the state of the communication link k between nodes i and j can be determined by its associated communication network elements and the influence weights of different communication network elements on the path, that is,

[0102]

[0103] Where ηm,k is the influence weight of the mth communication network element on the kth path. At this time, the fault of the communication network element is propagated to the communication link through the association relationship, and the status of the communication link can be obtained at this time; then, the fault impact is propagated to the information network element layer according to the status of the communication link, that is:

[0104]

[0105] Where, ζ k is the kth path pair LK ij The influence weight of .

[0106] In summary, we can derive the propagation path of faults from physical communication components to abstract information network components.

[0107] 2) Analysis of the impact of information components on automatic control systems;

[0108] For any information element LK ij , given its state, its impact on the automatic control system is based on the cyber-physical coupling model.,First, we analyze the impact of the abnormality of the information element on the amount of information it carries, and then analyze the impact of the information amount on the key physical indicators of the physical system:

[0109]

[0110] Among them, λ p is a key physical quantity (such as voltage, frequency), s c is a certain amount of information in the automatic control system (such as instructions, collection), f is the fault impact equation of information-physical coupling, and is the product of the sensitivity of information elements to information flow and the sensitivity of information flow to physical quantity.

Claims

1. A static model of an automatic control system information network, characterized in that: include: Information network component layer, communication link layer, network component layer; The information network element layer includes a measurement element unit composed of multiple measurement element sub-models, an information transmission path unit composed of information transmission path sub-models connecting each measurement element sub-model, an information calculation and processing unit, and an execution element unit composed of multiple execution element sub-models. The information network element layer is used to display the information flow transmission process of the automatic control system, including the interaction between the automatic control system and the physical power grid. The communication link layer is used to represent the communication link sub-model corresponding to any sub-model in the information network element layer; The network element layer is used to represent the network element sub-model corresponding to any communication link sub-model in the communication link layer; the network element sub-model is used to indicate the communication network elements included in the corresponding communication link; The measuring element unit is used to obtain the required physical quantity and convert it into the input of the information network; the information transmission path unit is used to transmit various types of data; the information calculation and processing unit is used to generate the control instructions of the system based on the set logic; the execution element unit is used to convert the control instructions carried by the information network information into actual physical quantities; The static model construction method comprises: First, based on the cyber-physical system coupling relationship, the information network component layer is constructed. This layer includes: physical quantity acquisition link, transmission path link, calculation and analysis link, downlink path link, and instruction execution link. The information network component layer also establishes the information processing function carried by each link. Secondly, based on the virtual channel of the power grid communication system, the communication link layer is established, including: link model for carrying information, primary and backup routes, and link status. Finally, based on the physical component model of the communication network, it is associated with the communication link. The construction of the information network element layer includes: 1) Construct the measurement component sub-model; For any measuring element n m , whose input is the state of the physical grid Output is the collection of system status F m It represents the measurement matrix, which represents the mapping of the actual signal through the acquisition process; The sub-model expression corresponding to the measurement element is as follows: 2) Construct the executive component sub-model; For any execution node n a , whose input is the control instruction of the upper branch Output is the receiving instruction of the actuator F a represents the execution matrix, which represents the mapping of control signals through the execution process; The sub-model expression corresponding to this execution node is as follows: 3) Construct the information transmission pathway sub-model; For any information transmission path T k , respectively, using column vectors and Represents the data of its input node and output node, then the information transmission path sub-model expression is as follows: Where, the matrix M k is a square matrix whose order is the same as the vector and same; 4) Construct information computing and processing units; For any business, use column vector and The expressions representing the data, information calculation and processing units of its input nodes and output nodes are as follows: Where, F c Represents the mapping function corresponding to this link.

2. The static model according to claim 1, characterized in that Also includes: When the measurement signal is collected without error, F m The element of F is 1; when the control signal is executed without error, a The element of M is 1; when the information transmission path is not disturbed, k is an identity matrix.

3. The static model according to claim 2, characterized in that The establishing of the communication link layer includes: 1) Constructing a data link set associated with information elements; The communication link layer is a collection of different data links from the start information element to the end information element, expressed as follows: Among them, Lk ij represents the set of communication links from information element i to information element j, represents the kth communication link from information element i to information element j, k = 1, 2, ..., N, and there are N communication link paths in this set; 2) Obtain the status of the communication link; For each communication link Establish its state bit State respectively l and status flag P l , where State l =0, when interrupted, State l =-1, State when bit error occurs l =1.

4. The static model according to claim 3, characterized in that Also includes: When State l =1, the bit error rate of the communication link is recorded.

5. The static model according to claim 4, characterized in that The physical component model based on the communication network is associated with the communication link, including: 1) For any communication link Let the associated set be: in, is the mth communication channel of the communication link k between information element i and information element j, and M is the total number of communication channels; 2) Obtain the status of the communication channel; For any communication channel Get its state bit State c and status flag P c , where State is normal c =0, when interrupted, State c =-1, State when bit error occurs c =1.

6. The static model according to claim 5, characterized in that Also includes: When State c =1, record the bit error rate of the channel.

7. A fault analysis method based on the static model as claimed in claim 6, characterized in that: include: 1) Establish the propagation path of the impact of component failure at each level; For any communication channel and its abnormal state According to the communication channel and communication link association, the communication link between communication elements i and j Status The calculation expression is as follows: Where η m,k is the influence weight of the mth communication network element on the kth path; The fault impact is propagated to the information network element layer in a weighted manner according to the status of the communication link, namely: Where, ζ k LK is the kth path pair ij The impact weight of 2) Analysis of the impact of information components on automatic control systems; For any information element LK ij ,The impact of the automatic control system is based on the ,cyber-physical coupling model.,First, the impact of the abnormal information component on the ,information volume is analyzed., and then the impact of the information volume on the ,key physical indicators of the physical system is analyzed. Among them, λ p is the set physical quantity, s c is the amount of information in the automatic control system; f is the fault impact equation of information-physical coupling, which is the product of the sensitivity of information elements to information flow and the sensitivity of information flow to physical quantities.

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