A power grid secondary system fault locating method based on signal path tracking

Abstract

The application discloses a power grid secondary system fault positioning method based on signal path tracking, and is based on a three-layer two-network architecture of an intelligent transformer substation, and comprises the following steps: S1: fault positioning network building: building a fault positioning network by taking a device port as a minimum unit; S2: network mathematical model parameter initialization: describing information transmission correlation of system physical wiring and a switch internal forwarding mechanism; S3: transmission path tracking: finding out an information transmission path by iteratively processing port numbers passed through by different types of signal transmission processes through a Boolean matrix; and S4: fault point positioning: determining a fault path and a non-fault path based on system device fault alarm information, so as to realize system fault point positioning. The application has high fault positioning precision, wide fault identification range, short positioning time and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of substation fault location, and particularly relates to a power grid secondary system fault location method based on signal path tracking. BACKGROUND

[0002] The intelligent substation specifies the data transmission standard requirements of the power equipment during the operation of the station control layer, the interval layer and the process layer in the secondary system with full-station information digitization, communication platform networking and information sharing standardization as basic requirements. However, with the transformation of the traditional 103 information model to the IEC61850 protocol, the network connection between various devices in the secondary system is increasingly complex, but the network connectivity fault is still mainly checked manually. The causes of the connectivity fault include device interface fault, disconnection fault, and poor contact between the terminal and the female plug port, etc. It is difficult to identify through naked eye, which leads to difficulty in troubleshooting during maintenance, delays the maintenance progress, and even causes equipment damage, bringing great hidden dangers to the safe operation of the power grid.

[0003] The intelligent substation technology has been widely promoted due to its information openness and information sharing advantages. Based on the state information coupling relationship and constraint model between secondary devices, it is possible to track the signal transmission path. By identifying the signal transmission path, the connectivity fault location can be effectively located, and the hidden fault can be eliminated.

[0004] The methods widely used in the current power secondary system fault location field are the image monitoring method based on computer vision technology and machine learning and the fault alarm method based on fault recording data information archiving. Among them, the computer vision positioning technology collects secondary system image data by deploying image sensing devices on site, analyzes and identifies the image morphological features, obtains the running state of the secondary system under different scenes and resolutions, and realizes online monitoring of the secondary devices. However, because deep learning itself has statistical characteristics, and the on-site environmental factors are complex, it is difficult to ensure 100% effectiveness of the fault identification result, and it cannot monitor the hidden faults such as connectivity damage.

[0005] With the improvement of the automation and intelligence level of the substation, more and more substations begin to be based on multi-source fusion of on-site information, analyze and archive fault information through information architecture enhancement and complementary redundant information between plants and substations, identify system fault modules, realize fault location, and the existing integrated platform and device intelligent alarm module can detect a wide range, but cannot realize accurate positioning of the secondary system fault point. There are many problems such as complex substation architecture, isolated main station information, and many false alarms of fault alarm, which seriously increase the difficulty of fault elimination, and even delay the progress of plant and substation maintenance, etc. It is difficult to ensure practicality and economy in field application. Therefore, improving the positioning accuracy and identification range of the power grid secondary system fault is an urgent problem for the present technical personnel. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a power grid secondary system fault positioning method based on signal path tracking, which has high fault positioning accuracy and wide fault recognition range.

[0007] To solve the above technical problems, the technical solutions adopted by the present application are as follows.

[0008] A power grid secondary system fault positioning method based on signal path tracking, based on the three-layer two-network architecture of an intelligent substation, comprising the following steps:

[0009] S1: Fault positioning network construction: constructing a fault positioning network with device ports as the minimum unit;

[0010] S2: Network mathematical model parameter initialization: describing the information transmission association relationship of the system physical wiring and the internal forwarding mechanism of the switch;

[0011] S3: Transmission path tracking: iterating the port numbers passed through by different types of signal transmission processes through a Boolean matrix to find out the information transmission path;

[0012] S4: Fault point positioning: based on the system device fault alarm information, determining the fault path and the non-fault path, thereby realizing system fault point positioning.

[0013] Preferably, the step S1 specifically comprises the following steps:

[0014] S11: Based on the object-oriented design idea, constructing an intelligent substation secondary system information description model architecture and a protocol IEC61850 communication data structure by standardizing the secondary physical devices, device logical functions and secondary network key nodes, unifying the protocols and realizing the integration of all station information;

[0015] S12: Constructing a secondary protection interval system network based on the three-layer two-network architecture of an intelligent substation and the protocol IEC61850 communication data structure in step S11;

[0016] S13: Constructing a secondary minimum system port model that can be positioned by a signal path tracking algorithm.

[0017] Preferably, the protocol IEC61850 communication data structure in step S11 comprises physical device groups for describing the characteristics of specific instance devices, logical device groups for dividing the functions of physical devices, logical node groups for describing the specific functions of logical devices, data object groups for describing the functions of logical nodes, and data attribute groups for describing data objects, which are in a hierarchical inclusion relationship.

[0018] Preferably, the secondary protection interval system network in step S12 is externally connected to a computer as the main control center in the system; the protection, metering and control devices in the three-layer two-network architecture are secondary devices in the system and contain their corresponding port labels; network communication is summarized by the station control layer bus or industrial switch and transmitted downward and fed back by physical wiring or switch internal forwarding mechanism.

[0019] Preferably, the secondary minimum system port model in step S13 contains all communication port constraints of the merging unit, intelligent terminal and relay protection device, switch group and other secondary measurement and control instruments in the three-layer two-network architecture, and identifies the physical connection relationship of each port in the station and the communication signal internal forwarding path in the switch.

[0020] Preferably, the secondary minimum system port model is divided into a physical layer association model and an information exchange layer association model according to whether the information interaction between ports is wired connection or switch internal forwarding mechanism; the information transmission association relationship in step S2 is to establish a signal and port description model according to the signal type and function sent by different devices in the secondary system; the signal and port description model includes:

[0021] Devices can be connected by physical wiring or achieve information interaction by switch internal forwarding mechanism, and then an association matrix A is established PP The physical connection relationship between device ports and ports in the secondary protection interval system is described, where p represents the port number, and its value is the number of all device ports in the system.

[0022]

[0023]

[0024] An association matrix Ipp is established to describe the information exchange association relationship between different device ports in the secondary protection interval system based on switch internal forwarding mechanism; if the switch internal information is unidirectional forwarding, the receiving port number is s, and the sending port number is e, then i se = 1, i es = 0.

[0025]

[0026]

[0027] In order to analyze the fault signal transmission path and exclude connectivity faults in the system connectivity analysis stage according to the fault information reported by the elements in the verification system, a signal and port description model sig pt is established to represent the corresponding relationship between different signal types and port numbers, and the matrix element S pt=1 represents the type of signal sent by the pth port is t;

[0028]

[0029] Preferably, the signal tracking algorithm flow is according to three signal and port association model A pp , I pp and sig pt , the transmission path of the signal between each port in the system is obtained according to the dependence of different signal types in the secondary protection interval system and the association of system elements.

[0030] Preferably, the calculation method of the signal transmission path in step S3 includes the following specific steps:

[0031] S31: system parameter initialization, input matrix A pp , I pp is established according to the secondary minimum system port model diagram to determine the association relationship between network ports;

[0032] S32: signal type initialization, determine the signal type existing in the system, and input matrix sig pt is used to determine the mapping relationship between each port in the signal transmission process according to the signal and port description model;

[0033] S33: iteration process, according to the signal source port number of each signal type, determine the matrix R 3(n-1) , the calculation formula is R 3(n-1) =A pp sig pt , and start iteration; wherein R 3(n-1) is the message port binding relationship at the current time, the element R 3(n-1) =1, that is, the signal is transmitted from the starting sending port to the target receiving port; the iteration criterion is whether the switch port number corresponding row vector in the R 3n-1 matrix contains a non-zero element, if there is no non-zero element, it means that the signal is successfully transmitted from the source end to the target port, and the iteration is ended.

[0034] S34: after the iteration is completed, the same signal type, that is, the same column element in sig pt , R 3(n-1) , R 3n-2 , R 3n-1 during the calculation process is extracted, and the corresponding port number output array P t is output, the element of which represents the port number combination through which the signal t is transmitted, that is, its transmission path.

[0035] Preferably, the fault point positioning in the step S4 relies on the alarm information received by the external computer sending SV messages to various devices of the secondary system, which is divided into two cases, one is the sub-device alarm response information caused by device configuration error, and the second is that when the response time of the sub-device after the handshake information of the external computer is sent exceeds the theoretical feedback time, the external computer as the main system defaults to the secondary system operation timeout, at this time, the handshake channel is judged as a fault path, that is, the message is disconnected.

[0036] Preferably, the alarm information and the abnormal transmission path discrimination can be obtained by Ports i err_i ∪P cor cor The fault port number set in all abnormal transmission paths is obtained, wherein the maximum value of i is the sum of the signal types contained in the system, P err_i is an abnormal signal transmission path, P cor is a normal signal transmission path.

[0037] When a single port fault may cause multiple channel abnormalities, after the abnormal channel port number set Ports i is obtained, the exact fault location can be obtained by obtaining the intersection of the ports contained in the abnormal channels, that is, {res} = Port1∩Port2···∩Port i , wherein the value range of i is 【1, n】, n is the sum of the signal types contained in the system, and res is the final obtained fault port.

[0038] Thanks to the above technical solutions, the technical progress achieved by the application is as follows.

[0039] The fault positioning accuracy of the application is high: the problem of difficulty in accurately positioning the hidden fault points of the power grid secondary system and troubleshooting is solved, the original inter-station positioning, regional positioning and fault device positioning are accurately positioned between the fault interconnection ports, which provides strong guidance for on-site maintenance and improves the positioning accuracy of hidden faults.

[0040] The fault recognition range is wide: the fault positioning method based on network graph theory realizes fault positioning by recognizing signal transmission paths, and can recognize hidden faults such as device interface faults, communication line disconnections, and poor contact of wiring terminals and female connectors, in addition to obvious damage to devices, insulation breakdown and other faults caused by serious accidents.

[0041] The positioning time is short: the fault port positioning relies on calculating the transmission paths of various types of signals in the system, after establishing the system network model, the control center can complete parameter initialization by sending SV handshake messages, and the operation speed is fast.

[0042] ​​Low cost: compared with traditional integrated information platform or fault recorder and other fault identification methods, the fault positioning method only needs to increase an external computer as a system controller during maintenance, and has strong replaceability and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 For the technical roadmap of the application;

[0044] Figure 2 For the existing three-layer two-network architecture of the intelligent substation;

[0045] Figure 3 For the information description model architecture of the secondary system of the intelligent substation of the application;

[0046] Figure 4 For the communication data structure diagram of the protocol IEC61850 of the application;

[0047] Figure 5 For the network diagram of the secondary protection interval system of the application;

[0048] Figure 6 For the secondary minimum system port model diagram of the application;

[0049] Figure 7 For the signal tracking algorithm flowchart of the application. DETAILED DESCRIPTION

[0050] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0051] A power grid secondary system fault positioning method based on signal path tracking, combined with Figure 1 As shown, based on the three-layer two-network architecture of the intelligent substation, it includes four main stages: S1: fault positioning network construction, S2: network mathematical model parameter initialization, S3: transmission path tracking and S4: fault point positioning, and the specific contents of each stage are as follows:

[0052] S1: fault positioning network construction, taking the device port as the minimum unit to build the fault positioning network;

[0053] S2: network mathematical model parameter initialization, describing the information transmission association relationship of the system physical wiring and the internal forwarding mechanism of the switch;

[0054] S3: transmission path tracking, through the iteration of the port number passed by the transmission process of different types of signals by the Boolean matrix, the information transmission path is found out;

[0055] S4: fault point positioning, based on the system device fault alarm information, the fault path and the non-fault path are determined, so as to realize the system fault point positioning.

[0056] As shown in Figure 2 The three-layer two-network basic architecture of the intelligent substation is shown in the figure, the station control layer contains system secondary side protection, measurement and control and metering device, and is connected to the secondary control center through the station control layer bus; the merging unit collects the voltage and current signals of the interval and the voltage and current signals transmitted by the merging unit of other intervals, and then converts them into SV message through merging synchronization + protocol conversion, and sends them to the interval layer devices such as protection device, measurement and control device, metering device and wave recording system for use; the intelligent terminal is responsible for collecting the primary side voltage and current signals and the switch position signal, and then connecting with the interval layer through optical fiber.

[0057] The fault positioning network of the application is built, and the specific steps include the following:

[0058] S11: Based on the object-oriented design idea, a smart substation secondary system information description model architecture and a protocol IEC61850 communication data structure are constructed by standardizing the secondary physical device, device logical function and secondary network key node, unifying the protocol and realizing the integration of all station information.

[0059] The smart substation secondary system information description model architecture is shown in Figure 3 The protocol IEC61850 communication data structure is shown in Figure 4 The protocol IEC61850 communication data structure includes physical device group, logical device group, logical node group, data object group and data attribute group from top to bottom, wherein the physical device group is used to describe the specific instance device characteristics; the logical device group is used to divide the physical device function; the logical node group is used to describe the specific function of the logical device; the data object group is used to describe the function of the logical node; and the data attribute group is used to describe the data object.

[0060] S12: Based on the three-layer two-network architecture of the smart substation and the protocol IEC61850 communication data structure in step S11, a secondary protection interval system network is constructed.

[0061] The secondary protection interval system network is shown in Figure 5 The external computer is used as the main control center of the system, is a system level device, has the highest priority, is responsible for system signal processing, and feeds back the data and operation results collected by the system in the verification process to the test personnel in real time; the protection, metering and measurement and control devices in the three-layer two-network architecture are used as the secondary devices of the system and contain their corresponding port marks; the network communication is summarized by the station control layer bus or industrial switch, and is transmitted and fed back by physical wiring or switch internal forwarding mechanism.

[0062] S13: A secondary minimum system port model capable of locating the fault port through signal path tracking algorithm is constructed.

[0063] The secondary minimum system port model is shown inFigure 6 The diagram shows all communication port constraints for the merging unit, intelligent terminals, relay protection devices, switch groups, and other secondary measurement and control instruments in the three-layer, two-network architecture. It also identifies the physical connection relationships between each port within the station and the communication signal forwarding paths within the switch. This model enables faulty port location using a signal path tracing algorithm.

[0064] Device ports are the basic units for information exchange between each component and other external devices. Based on network graph theory, a mathematical model of the system network is established with device ports as the minimum unit. The secondary minimum system port model is divided into a physical layer association model and an information exchange layer association model, depending on whether the information exchange between ports is a wired connection or an internal forwarding mechanism within the switch. Furthermore, the information transmission association relationship in step S2 establishes a signal and port description model based on the signal type and function sent by different devices in the secondary system. The signal and port description model includes:

[0065] Devices can be connected through physical wiring or through the internal forwarding mechanism of the switch to achieve information exchange, so the correlation matrix A is established. PP Describes the physical connection relationship between device ports in the secondary protection interval system. p represents the port number, which is the number of all device ports in the system.

[0066]

[0067]

[0068] Establish the association matrix Ipp to describe the information exchange association relationship between different device ports in the secondary protection interval system based on the internal forwarding mechanism of the switch. It should be noted that if the internal information of the switch is forwarded in one direction, the port number of the receiving information is s and the port number of the sending information is e, then i se =1,i es =0.

[0069]

[0070]

[0071] At the same time, in order to analyze the fault signal transmission path and eliminate connectivity faults according to the fault information reported by the components in the secondary protection interval system during the system connectivity analysis phase, a signal and port description model sig is established. pt It is used to represent the correspondence between different signal types and port numbers. The matrix element S pt =1 indicates that the signal type sent by the pth port is t.

[0072]

[0073] The signal path tracking and fault point positioning algorithm principle in step S4 is as follows:

[0074] The signal tracking algorithm flow is to obtain the transmission path of the signal between each port of the system according to the dependence relationship of different signal types in the checking network and the system element association based on the above three signal and port association models A pp 、 pp and sig pt . The calculation method of the signal transmission path in step S3 is shown in Figure 7 , and the specific steps include:

[0075] S31: System parameter initialization, input matrix A pp 、 pp is established according to the secondary minimum system port model diagram to determine the association relationship between network ports;

[0076] S32: Signal type initialization, determine the signal type existing in the system, and input matrix sig pt is used to determine the mapping relationship between each port in the signal transmission process according to the signal and port description model;

[0077] S33: Iteration process, determine matrix R 3(n-1) according to the signal source port number of each signal type, the calculation formula is R 3(n-1) =A pp sig pt , and start iteration; wherein R 3(n-1) is the message port binding relationship at the current time, and the element R 3(n-1) =1, that is, the signal is transmitted from the starting sending port to the target receiving port; the iteration criterion is whether the switch port number corresponding row vector in R 3n-1 matrix contains a non-zero element, if there is no non-zero element, it means that the signal is successfully transmitted from the source end to the target port, and the iteration is ended; if there is a non-zero element, return to R 3n-2 matrix.

[0078] S34: After the iteration is completed, the same signal type (the same column element) in sig pt , R 3(n-1) , R 3n-2 , R 3n-1 in the calculation process is extracted, and the corresponding port number (row number) output array P t is output, and the element represents the port number combination that the signal t transmits through, that is, the transmission path.

[0079] The fault point positioning depends on the alarm information received by the external computer sending SV messages to various devices of the secondary system. The alarm information is divided into two cases. The first case is the sub-device alarm response information caused by device configuration error. The second case is that when the sub-device does not respond within the theoretical feedback time after the external computer sends handshake information, the external computer as the main system defaults to the secondary system operation timeout. At this time, the handshake channel is judged as a fault path, that is, the message is disconnected.

[0080] According to the above alarm information and abnormal transmission path judgment, Ports i = P err_i ∪ P cor -P cor The fault port number set in all abnormal transmission paths is obtained, where the maximum value of i is the sum of the signal types contained in the system, P err_i is the abnormal signal transmission path, and P cor is the normal signal transmission path.

[0081] When the secondary system actually communicates, a single port failure may cause multiple channel abnormalities. After determining the abnormal channel port number set Ports i , the exact fault location can be obtained by finding the intersection of the ports contained in the abnormal channel, that is, res = Ports i 1∩Ports i 2···∩Ports i i, where the value of i is in the range of 【1, n】 and n is the sum of the signal types contained in the system, and res is the final fault port.

Claims

1. A signal path tracing based power grid secondary system fault location method based on a three-layer two-network architecture of a smart substation, characterized in that: The method comprises the following steps: S1: fault location network building: building a fault location network with device ports as the minimum unit; S2: network mathematical model parameter initialization: describing the information transmission association relationship of the system physical wiring and the internal forwarding mechanism of the switch; The information transmission association relationship in the step S2 is to establish a signal and port description model according to the signal types and functions sent by different devices in the secondary system; the signal and port description model comprises: The devices can be connected through physical wiring or through the internal forwarding mechanism of the switch to realize information interaction, and then the association matrix is established A PP The physical connection relationship between the device ports and the ports in the secondary protection interval system is described, wherein p represents the port number, and the value is the number of all device ports in the system; Establishing a correlation matrix I The pp describes the information exchange correlation relationship between different device ports in the secondary protection interval system based on the internal forwarding mechanism of the switch; if the internal information of the switch is one-way forwarding, the port number of the receiving information is s, and the sending port number is e, then i se =1, i es =0; In order to analyze the signal transmission path and eliminate the connectivity fault according to the fault information of the elements in the checking system in the system connectivity analysis stage, a signal and port description model is established sig pt For representing the corresponding relationship between different signal types and port numbers, the matrix element S pt = 1 represents that the signal type sent by the pth port is t. ； S3: transmission path tracking: finding out the information transmission path by iterating the port numbers passed by different types of signal transmission processes through a Boolean matrix; The calculation method of the signal transmission path in the step S3 comprises the following steps: S31: system parameter initialization, according to the secondary minimum system port model diagram to establish input matrix A pp 、 I pp , determine the association relationship between network ports; S32: signal type initialization, determine the signal types existing in the system, according to the signal and port description model input matrix sig pt for the signal path tracking algorithm to determine the mapping relationship with each port in the signal transmission process; S33: Iterative process, according to the source port number of each signal type, determine the matrix R 3(n-1) , which is calculated as R 3(n-1) = A pp sig pt , and start iteration; where R 3(n-1) is the message port binding relationship at the current moment, element R 3(n-1) =1, that is, the signal is transmitted from the starting sending port to the target receiving port; the iteration criterion is R 3n-1 Check whether the row vector corresponding to the switch port number in the matrix contains non-zero elements. If there are no non-zero elements, it means that the signal is successfully transmitted from the source port to the target port, and the iteration ends. S34: After the iteration is completed, the calculation process in the iteration is extracted sig pt , R 3(n-1) , R 3n-2 , R 3n-1 The same signal type, that is, the same column element, corresponds to the port number output array P t , and the elements represent the port number combination through which the signal t is transmitted, that is, its transmission path; S4: fault point location: determining the fault path and the non-fault path based on the system device fault alarm information, so as to realize the fault point location of the system; The fault point location in the step S4 depends on the alarm information received by the external computer when sending SV messages to various devices of the secondary system; the alarm information is divided into two cases: one is the sub-device alarm response information caused by device configuration error, and the other is that when the response time of the sub-device to the handshake information sent by the external computer exceeds the theoretical feedback time, the external computer of the main system is defaulted as the secondary system operation timeout of the secondary system, at this time, the handshake channel is judged as the fault path, that is, the message is disconnected; The alarm information and the abnormal transmission path determination can be realized by obtaining a fault port number set in all abnormal transmission paths, wherein the maximum value of i is the sum of signal types contained in the system, P err_i an abnormal signal transmission path, P cor a normal signal transmission path; When a single port failure can cause multiple channel abnormality, determine the abnormal channel port number set Ports i After that, by finding the intersection of the port numbers contained in the abnormal channels, the formula {res} = Port1∩Port 2··· ∩Port i The exact failure location can be obtained, where the value range of i is 【1, n】, n is the sum of the signal types contained in the system, and res is the final obtained failure port.

2. The method of claim 1, wherein the method further comprises: The step S1 specifically comprises the following steps: S11: based on the object-oriented design idea, constructing a secondary system information description model architecture and a protocol IEC61850 communication data structure for realizing the information integration of the intelligent substation by standardizing the secondary physical devices, device logical functions and key nodes of the secondary network, and unifying the protocols; S12: constructing a secondary protection interval system network based on the three-layer two-network architecture of the intelligent substation and the protocol IEC61850 communication data structure in the step S11; S13: constructing a secondary minimum system port model capable of locating the fault port through the signal path tracking algorithm.

3. The method of claim 2, wherein: The protocol IEC61850 communication data structure in the step S11 comprises physical device groups, logical device groups, logical node groups, data object groups and data attribute groups, which are in a containing relationship and are used to describe the characteristics of specific instance devices.

4. The method of claim 3, wherein: The secondary protection interval system network in the step S12 takes the external computer as the main control center in the system; the protection, metering and measurement and control devices in the three-layer two-network architecture are taken as secondary devices of the system and contain the corresponding port marks; the network communication is summarized by the station control layer bus or industrial switch to realize the downward transmission and feedback through physical wiring or internal forwarding mechanism of the switch.

5. The method of claim 4, wherein: The secondary minimum system port model in the step S13 contains all communication port constraints of the merging unit, intelligent terminal and relay protection device, switch group and other secondary measurement and control instruments in the three-layer two-network architecture, and identifies the physical connection relationship of each port in the station and the internal forwarding path of the communication signal in the switch.

6. The method of claim 5, wherein: The secondary minimum system port model is divided into a physical layer association model and an information exchange layer association model according to whether information interaction between ports is a wired connection or a switch internal forwarding mechanism.

7. The method of claim 6, wherein: The signal tracking algorithm process is to obtain the transmission path of the signal between each port of the system according to the dependency relationship of different signal types in the secondary protection interval system and the port and the system element association. A pp 、 I pp and sig pt , the transmission path of the signal between each port of the system is obtained according to the dependency relationship of different signal types in the secondary protection interval system and the port and the system element association.

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