CN112821565A

CN112821565A - Automatic defect positioning method for relay protection system level test

Info

Publication number: CN112821565A
Application number: CN202110254249.5A
Authority: CN
Inventors: 连立军; 尹浩轩; 杨阳; 李泽卿
Original assignee: State Grid Corp of China SGCC; State Grid Hebei Electric Power Co Ltd; Xingtai Power Supply Co of State Grid Hebei Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; State Grid Hebei Electric Power Co Ltd; Xingtai Power Supply Co of State Grid Hebei Electric Power Co Ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2021-05-18

Abstract

The invention discloses a method for automatically positioning a defect for a relay protection system level test, which is characterized by establishing an intelligent substation process layer network data flow model and providing a method for automatically positioning a defect for a relay protection system level test based on the model; by using the method, when the relay protection system is checked, accepted, debugged and checked, the automatic positioning of the defects is realized according to the test result. The invention provides a defect positioning method for relay protection system level test, which establishes a relay protection data flow model, wherein the model comprises a port connection model and a message publishing/subscribing model. Based on the model, the invention provides a defect positioning method for relay protection testing, and example analysis shows that the defect positioning method can accurately position the defect to a fault port and an adjacent link thereof, can effectively help testers to quickly find the defect, improves the testing efficiency of a relay protection system, and has important significance for improving the reliability of the relay protection system.

Description

Automatic defect positioning method for relay protection system level test

Technical Field

The invention relates to a method for automatically positioning defects in a relay protection system level test, and belongs to the technical field of relay protection systems.

Background

Under the conditions of information networking transmission and unified modeling of an intelligent substation relay protection system, on one hand, a communication network becomes an important link for realizing a relay protection function, the connectivity directly influences the reliability of relay protection, and a relay protection test should take the communication network as an indispensable part; on the other hand, the coupling between each relay protection device is more intimate compared with the conventional relay protection, and the test of the relay protection of the intelligent substation needs to pay attention to whether the information subscription relation of the protection device is correct, whether a hidden fault exists and the like besides the functions of the single protection device.

Currently, a single-body testing method of conventional substation relay protection is basically used for intelligent substation relay protection, and whether the function of a protection device meets requirements or not is tested mainly by connecting a relay protection tester to a relay protection device and generating a corresponding signal by the tester. However, the testing method for the single equipment lacks integrity, and cannot test the relay protection equipment together with a communication network, and also cannot test whether the information subscription relationship and the matching condition between the relay protection equipment meet the requirements. It can be seen that the validity of the test mode of the conventional relay protection system is questioned, and the requirement of the relay protection test of the intelligent substation cannot be met

In recent years, attention is paid to an intelligent substation relay protection system level testing technology, but because of complexity of a process layer network, communication relations among all devices in an intelligent substation relay protection system are not as clearly visible as those of a conventional substation, so that the system level testing technology has a short board in defect positioning, although the whole relay protection system can be tested, once a defect or a fault exists in the process layer network, a tester cannot directly find an actual position of the fault defect through a testing result, popularization of the system level testing technology is limited to a certain extent, and much inconvenience is brought to testing of the relay protection system.

Disclosure of Invention

The invention aims to solve the technical problems that a process layer network data flow model of an intelligent substation is established, and a defect automatic positioning method for relay protection system level test is provided based on the model; by using the method, the automatic positioning of the defects can be realized according to the test result when the relay protection system is checked, accepted, debugged and checked regularly.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a method for automatically positioning a defect for a relay protection system level test is characterized by establishing an intelligent substation process layer network data flow model and providing a method for automatically positioning a defect for a relay protection system level test based on the model; by using the method, when the relay protection system is checked, accepted, debugged and checked, the automatic positioning of the defects is realized according to the test result.

As a further improvement of the invention, a defect positioning module is added in the functional architecture of the system level tester; and establishing a relay protection data flow model which comprises a port connection model, a message publishing model and a message subscribing model.

As a further improvement of the present invention, the functional architecture of the system-level tester includes a total station primary simulation module, a model maintenance module, a graphical interface module, an SCD parsing module, a packet packaging and outputting module, a packet receiving and parsing module, and a defect locating module;

the graphical interface module realizes the visualized primary system simulation configuration and the parameter input of a model, the primary system simulation configuration parameters are input into the total station primary simulation module, and the model parameters are input into the model maintenance module;

the SCD analysis module is responsible for analyzing the total station data model in the SCD and inputting the analyzed data into the model maintenance module; the model maintenance module is responsible for maintaining and providing a primary system real-time simulation model for the total-station primary simulation module and the message package and output module;

the message packet and output module generates and outputs corresponding SV messages and GOOSE messages according to the total station data model and the simulation data and transmits the SV messages and the GOOSE messages to a process layer network;

the message receiving and analyzing module is responsible for receiving GOOSE messages in a process layer network and sending switch displacement signals to the primary system simulation module;

and the defect positioning module automatically positions the defects after the defects are found by testing the content of the GOOSE messages analyzed by the message receiving and analyzing module.

As a further improvement of the invention, the port connection model is constructed as follows: the process layer network connects the intelligent terminal of the merging unit and the relay protection equipment with each other;

the transformer bay switch comprises 6 ports in total: the port 1 and the port 3 are respectively connected with a port 10 of a high-voltage side MU and a port 11 of a low-voltage side MU, the port 2 and the port 4 are respectively connected with a port 7 of a high-voltage side IT and a port 8 of a low-voltage side IT, and the port 5 is respectively connected with a port 12 of a main transformer body IT and a port 9 of a main transformer protection intelligent electronic device; assuming that the protection IED receives messages sent by the high-voltage side MU, the low-voltage side MU, the high-voltage side IT, the low-voltage side IT and the main transformer body IT, and the high-voltage side IT, the low-voltage side IT and the main transformer body IT receive messages sent from the protection IED, the ports are represented by nodes, and the connection relationship is represented by arcs, a process layer network communication relationship can be drawn as a directed graph to represent. As a further improvement of the present invention, to describe the physical connection relationship of the process layer network, a P × P matrix W is defined, where P represents the total number of ports in the process layer network; if there is a solid arc pointing from node j to node i, then element W in matrix W_ijThe value is 1, otherwise, the value is 0; the matrix W is obtained through the topological structure of the process layer network, and the process layer network matrix W_12×12Can be expressed as

In order to express the logical connection relation of the process layer network, a P multiplied by P matrix L is defined, wherein P represents the total number of ports in the process layer network; if there is a dashed arc pointing from node j to node i, then the element L in the matrix L_ijThe value is 1, otherwise, the value is 0; the matrix L is obtained through VLAN configuration information of a process layer network_12×12Can be expressed as

By combining the matrixes W and L, the connection relation matrix C of the process layer network can be obtained by the formula (3);

C＝W+L (3)。

as a further improvement of the present invention, the message publishing model is used to describe an association relationship between a message and a port sending the message, and is constructed as follows: assuming that the number of messages sent by all IEDs in the process level network is B, a matrix F of P × B is defined, and if a port i issues a message j, an element F of the matrix_ijEqual to 1, otherwise, equal to 0;

the message subscription model is used for describing the incidence relation between the message and the port for receiving the message, and is constructed as follows: assuming that the number of messages sent by all IEDs in the process level network is B, a matrix D of P × B is defined, and if a port i subscribes to a message j, an element D of the matrix_ijEqual to 1, otherwise, equal to 0.

As a further improvement of the present invention, the data flow model established by the data flow model-based defect location method obtains transmission path information of the message or result information of the relay protection test to perform defect location.

As a further development of the invention, the message transmission path P_i-jIs a set of port connection relations experienced by a message transmitted from a node i to a node j, the transmission path of the message can be expressed by a P x P matrix H, if P is P_a-cGiven { a-b, b-c }, then any element H of matrix H_ijTake a value of

In order to obtain the transmission path of the message, the matrices W, L and F are initialized based on the information of the process layer network, and then the calculation is performed by using the equations (5) to (7)

F⁰＝W×F (5)

F^3k-2＝L×F3^(k-1) (6)

F^3k-1＝W×F^3(k-2) (7)

In the formula: k is the iteration number of the message path acquisition algorithm;

first, a matrix F is obtained by equation (5)⁰Using W to multiply the matrix F to the left means that the message is transmitted once along the physical connection. Then, the matrix F is obtained by equation (6)^3k-2In equation (6), the matrix L is used to multiply the matrix F^3(k-1)Meaning that the message is transmitted once along the logical connection; reuse formula (7) acquisition matrix F^3k-1When a message arrives at a non-switch port, it is not further transmitted, i.e. the end of the transmission is reached, so the element in F3k-1 is processed, if F is the case^3k-1Non-zero element F in (1)_ij ^3k-1Corresponding to a non-switch port, the element is set to zero, and then a matrix F can be obtained^3k(ii) a Obtain the matrix F^3kThen, whether non-zero elements exist in the matrix needs to be checked so as to confirm whether all messages reach the destination; if F^3kIf there are no more nonzero elements, the iterative calculation is ended, if F^3kIf there are non-zero elements, k is set to k +1 and the iteration continues until F^3kNo non-zero elements; after the iteration is finished, the matrix F, F obtained in the iteration process is used⁰、F^3k-2And F^3k-1And arranging according to the superscript, so that the transmission path of each message can be obtained.

As a further improvement of the invention, the defect positioning operation is carried out according to the result information of the relay protection test as follows: when the relay protection test of the process layer network is carried out, the test equipment sends SV messages to the relay protection system, and then whether the tested function is normal is judged according to the returned GOOSE messages.

As a further improvement of the invention, if only one single point defect exists in the process layer network at the same time, if the defect exists in the process layer network, the message of more than one link is influenced; by analyzing the alarm information of the broken message link generated in the device test, if m message links are affected and the total number of the message links is n, the defect positioning matrix G can be obtained by the formula (8)

In the formula: the matrix K is an intermediate matrix; matrix HⁱA message link corresponding to the broken link; h^jCorresponding to a packet link without defects.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

the invention provides a defect positioning method for relay protection system level test, which establishes a relay protection data flow model, wherein the model comprises a port connection model and a message publishing/subscribing model. Based on the model, the invention provides a defect positioning method for relay protection testing, and example analysis shows that the defect positioning method can accurately position the defect to a fault port and an adjacent link thereof, can effectively help testers to quickly find the defect, improves the testing efficiency of a relay protection system, and has important significance for improving the reliability of the relay protection system.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is an architecture diagram of a system level test method;

FIG. 2 is a diagram of a main transformer interval relay protection system;

FIG. 3 is a port connection graph;

FIG. 4 is a circuit diagram of a common flaw in a process level network;

FIG. 5 is a simplified relay protection system topology;

FIG. 6 is a table of filled circles and their corresponding devices;

FIG. 7 is a table of relationships between messages and their publish-subscribe relationships;

fig. 8 is a table of defect localization results.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Specifically, as shown in fig. 1, a defect locating module is added to a functional architecture of the system level tester; and establishing a relay protection data flow model which comprises a port connection model, a message publishing model and a message subscribing model.

Specifically, the functional architecture of the system-level tester comprises a total-station primary simulation module, a model maintenance module, a graphical interface module, an SCD analysis module, a message packaging and outputting module, a message receiving and analyzing module and a defect positioning module; the graphical interface module realizes the visualized primary system simulation configuration and the parameter input of a model, the primary system simulation configuration parameters are input into the total station primary simulation module, and the model parameters are input into the model maintenance module;

Specifically, as shown in fig. 2, a process layer network of a typical intelligent substation main transformer interval is constructed, where the port connection model is constructed as follows: the process layer network connects the intelligent terminal of the merging unit and the relay protection equipment with each other;

the transformer bay switch comprises 6 ports in total: the port 1 and the port 3 are respectively connected with a port 10 of a high-voltage side MU and a port 11 of a low-voltage side MU, the port 2 and the port 4 are respectively connected with a port 7 of a high-voltage side IT and a port 8 of a low-voltage side IT, and the port 5 is respectively connected with a port 12 of a main transformer body IT and a port 9 of a main transformer protection intelligent electronic device; assuming that the protection IED receives messages sent by the high-voltage side MU, the low-voltage side MU, the high-voltage side IT, the low-voltage side IT and the main transformer body IT, and the high-voltage side IT, the low-voltage side IT and the main transformer body IT receive messages sent from the protection IED, the ports are represented by nodes, and the connection relationship is represented by arcs, the process layer network communication relationship can be drawn as a directed graph, and the directed graph is shown in fig. 3.

Solid lines shown in fig. 3 are used to indicate physical connections between ports, and the physical connections are constructed using physical transmission media such as optical fibers. All solid-line arcs are bi-directional, mainly because the switch ports of the process-level network often employ duplexing functions. The dashed arcs shown in fig. 3 represent logical connections that are constructed by the control logic of the switch. When a message enters the switch, the control logic of the switch determines to which output port or ports the message is directed. In the process layer network of the intelligent substation, the control logic of the switch is mainly related to the configuration of the virtual local area network, and the VLAN is used for limiting unnecessary flow in the network, reducing network load and improving network performance in the process layer network

Specifically, in order to describe the physical connection relationship of the process layer network, a P × P matrix W is defined, where P represents the total number of ports in the process layer network; if there is a solid arc pointing from node j to node i, then element W in matrix W_ijThe value is 1, otherwise, the value is 0; the matrix W is obtained through the topological structure of the process layer network, and the process layer network matrix W_12×12Can be expressed as

In order to express the logical connection relation of the process layer network, a P multiplied by P matrix L is defined, wherein P represents the total number of ports in the process layer network; if there is a dashed arc pointing from node j to node i, then the element L in the matrix L_ijThe value is 1, otherwise, the value is 0; matrix L throughVLAN configuration information of a process level network is obtained, and a matrix L of the process level network_12×12Can be expressed as

C＝W+L (3)。

specifically, the message publishing model is used for describing an association relationship between a message and a port for sending the message, and is constructed as follows: assuming that the number of messages sent by all IEDs in the process level network is B, a matrix F of P × B is defined, and if a port i issues a message j, an element F of the matrix_ijEqual to 1, otherwise, equal to 0;

Specifically, the data flow model established by the data flow model-based defect location method obtains transmission path information of the message or result information of the relay protection test to perform defect location.

In particular, the message transmission path P_i-jIs a set of port connection relations experienced by a message transmitted from a node i to a node j, the transmission path of the message can be expressed by a P x P matrix H, if P is P_a-cGiven { a-b, b-c }, then any element H of matrix H_ijTake a value of

F⁰＝W×F (5)

F^3k-2＝L×F^3(k-1) (6)

F^3k-1＝W×F^3(k-2) (7)

first, a matrix F is obtained by equation (5)⁰Using W to multiply the matrix F to the left means that the message is transmitted once along the physical connection. Then, the matrix F is obtained by equation (6)^3k-2In equation (6), the matrix L is used to multiply the matrix F³⁽k^-1)Meaning that the message is transmitted once along the logical connection; reuse formula (7) acquisition matrix F^3k-1When a message arrives at a non-switch port, it is not further transmitted, i.e. the end of the transmission is reached, so the element in F3k-1 is processed, if F is the case^3k-1Non-zero element F in (1)_ij ^3k-1Corresponding to a non-switch port, the element is set to zero, and then a matrix F can be obtained^3k(ii) a Obtain the matrix F^3kThen, whether non-zero elements exist in the matrix needs to be checked so as to confirm whether all messages reach the destination; if F^3kIf there are no more nonzero elements, the iterative calculation is ended, if F^3kIf there are non-zero elements, k is set to k +1 and the iteration continues until F^3kNo non-zero elements; after the iteration is finished, the matrix F, F obtained in the iteration process is used⁰、F^3k-2And F^3k-1And arranging according to the superscript, so that the transmission path of each message can be obtained. Specifically, the defect positioning operation is performed according to the result information of the relay protection test as follows: when the relay protection test of the process layer network is carried out, the test equipment sends SV messages to the relay protection system, and then whether the tested function is normal is judged according to the returned GOOSE messages.

The abnormal test result information includes the following 2 types.

(1) All the IEDs under test can receive the messages subscribed by them normally, but the trip or control information in the GOOSE message returned by the testing device does not meet the expected requirements, in which case it can be determined that the defect occurs in the IED associated with this piece of control and trip information.

(2) One or more of the tested IEDs send out an information chain-breaking alarm, in which case it can be judged that a defect occurs in the process level network. A common deficiency of the process level network is shown in fig. 4.

The defects corresponding to the numbers in fig. 4 are: the publishing/subscribing relation described in the SCD file is incorrect; the IP address or other configuration of the equipment port is wrong, or the port of the equipment is defective; the wrong network connection relation or the network connection between the switch and the IED is broken; fourthly, the configuration of VLAN or multicast is not correct.

Specifically, considering that the probability of multi-point defects is low, it is assumed that only one single-point defect exists in the layer network in the same time process. If a defect exists in the process layer network, the message of more than one link is affected; by analyzing the alarm information of the broken message link generated in the device test, if m message links are affected and the total number of the message links is n, the defect positioning matrix G can be obtained by the formula (8)

Defect localization may utilize the information in matrix G. Suppose G_ijThe element with the largest value in the matrix G, if the connection i-j corresponds to a physical connection, it can be determined that a defect occurs in the port i or j (corresponding to defects (r) and (r)), or in the physical connection between the port i and the port j (corresponding to defect (c)). If i-j corresponds to a logical connection, it can be determined that there is a problem with the control logic of the switch that relates to port i or j (corresponding to defect). The effectiveness of the method is verified by taking a simplified relay protection system as shown in fig. 5 as an example.

In fig. 5, the process layer network is composed of 3 switches, and switches 1, 2, and 3 are line bay switches, main bay switches, and central switches, respectively. The filled circles represent ports of the IEDs and MUs, the open circles represent ports of the switch, and the ports are numbered in order from 1 to 28, and the filled circles and their opposite device names are shown in the table of fig. 6. The relationship between each message and its corresponding publish-subscribe relationship in the relay protection system is shown in the table of fig. 7.

Suppose that the relay protection system has 8 defects (a), (b), (g) and (h) shown in fig. 5, which correspond to the defects (i) and (ii) in fig. 4, the defects (c) and (e) in fig. 5, which correspond to the defects (i) in fig. 4, and the defects (d) and (f) in fig. 5, which correspond to the defects (i) in fig. 4. To verify the effectiveness of the method, the method was used to locate and analyze the defects as they occurred in FIG. 5, respectively.

First, the calculation steps of the method are described by taking defects (a) and (c) as examples. If the defect (a) exists during the test, the line protection IED and the bus protection IED send out an S1 message chain breakage alarm, and based on the alarm information generated during the equipment test and a message transmission path acquisition algorithm, the message transmission link affected by the defect (a) can be known to be a message transmission link affected by the defect (a)

P_3-1＝[3-15，15-13，13-1]

P_3-4＝[3-15，15-16，16-17，17-18，18-4]

Thus, n and m in formula (6) are equal to 30 and 2, respectively. The maximum value elements in the matrix G are G3-15 and G15-3, which are equal to 4, as can be seen from the calculation of equation (6). Considering that 3-15 correspond to physical connections, it can be analytically determined that defects (a) may occur at either

port

3 or 5, or at the fiber between

ports

3 and 5.

If there is a defect (c) during the test, the line IT will send out a message G3 chain breakage alarm, the bus protection IED will send out the chain breakage alarms of messages G1, G2 and S1, and the bus voltage MU will send out the chain breakage alarm of message G2. Based on the alarm information generated during the equipment test and the message transmission path acquisition algorithm, the message transmission link influenced by the defect (a) can be known to be

P_3-4＝[3-15，15-16，16-17，17-18，18-4]

P_1-4＝[1-13，13-16，16-17，17-18，18-4]

P_2-4＝[2-14，14-16，16-17，17-18，18-4]

P_2-6＝[2-14，14-16，16-17，17-21，21-4]

P_4-2＝[4-18，18-17，17-16，16-14，14-2]

Therefore, m in formula (8) is equal to 5. The maximum value elements in the matrix G are G16-17 and G17-16, which are equal to 10, as can be seen from the calculation of equation (8). Considering that 16-17 correspond to a physical connection, it can be analytically determined that a defect (a) may occur at either port 16 or 17, or at the fiber between ports 16 and 17.

The other defects in FIG. 5 were located using the method described above, and the results are shown in FIG. 8; the defect positioning method can position the defect to the fault port and the adjacent link thereof, and effectively helps testers to quickly find the defect.

Claims

1. A method for automatically positioning a defect of a relay protection system level test is characterized by comprising the following steps: establishing an intelligent substation process layer network data flow model, and providing a relay protection system level test oriented defect automatic positioning method based on the model; by using the method, when the relay protection system is checked, accepted, debugged and checked, the automatic positioning of the defects is realized according to the test result.

2. The automatic defect positioning method for relay protection system level test according to claim 1, wherein: a defect positioning module is added in a functional framework of the system level tester; and establishing a relay protection data flow model which comprises a port connection model, a message publishing model and a message subscribing model.

3. The automatic defect positioning method for relay protection system level test according to claim 2, wherein: the functional architecture of the system-level tester comprises a total-station primary simulation module, a model maintenance module, a graphical interface module, an SCD analysis module, a message packaging and output module, a message receiving and analysis module and a defect positioning module;

the SCD analysis module is responsible for analyzing the total station data model in the SCD and inputting the analyzed data into the model maintenance module;

the model maintenance module is responsible for maintaining and providing a primary system real-time simulation model for the total-station primary simulation module and the message package and output module;

4. The automatic defect positioning method for relay protection system level test according to claim 3, wherein: the port connection model is constructed as follows: the process layer network connects the intelligent terminal of the merging unit and the relay protection equipment with each other;

the transformer bay switch comprises 6 ports in total: the port 1 and the port 3 are respectively connected with a port 10 of a high-voltage side MU and a port 11 of a low-voltage side MU, the port 2 and the port 4 are respectively connected with a port 7 of a high-voltage side IT and a port 8 of a low-voltage side IT, and the port 5 is respectively connected with a port 12 of a main transformer body IT and a port 9 of a main transformer protection intelligent electronic device.

5. The automatic defect positioning method for relay protection system level test according to claim 4, wherein: to describe the physical connection of the process layer network, a PxP matrix W is defined, where P denotesThe total number of ports in the tier network; if there is a solid arc pointing from node j to node i, then element W in matrix W_ijThe value is 1, otherwise, the value is 0; the matrix W is obtained through the topological structure of the process layer network, and the process layer network matrix W_12×12Can be expressed as

C＝W+L (3)。

6. the automatic defect positioning method for relay protection system level test according to claim 3, wherein: the message publishing model is used for describing the incidence relation between a message and a port for sending the message, and is constructed as follows: assuming that the number of messages sent by all IEDs in the process level network is B, a matrix F of P × B is defined, and if a port i issues a message j, an element F of the matrix_ijEqual to 1, otherwise, equal to 0;

the message subscription model is used for describing the incidence relation between the message and the port for receiving the message, and is constructed as follows: assuming that the number of messages sent by all IEDs in the process level network is B, a matrix D of P × B is defined, and if a port i subscribes to a message j, an element D of the matrix_ijEqual to 1, otherwise,equal to 0.

7. The automatic defect positioning method for relay protection system level test according to claim 3, wherein: the data flow model established by the data flow model-based defect positioning method obtains transmission path information of the message or result information of the relay protection test to perform defect positioning.

8. The automatic defect positioning method for relay protection system level test according to claim 7, wherein: the transmission path of the message is obtained as follows: packet transmission path P_i-jIs a set of port connection relations experienced by a message transmitted from a node i to a node j, the transmission path of the message can be expressed by a P x P matrix H, if P is P_a-cGiven { a-b, b-c }, then any element H of matrix H_ijTake a value of

F⁰＝W×F (5)

F^3k-2＝L×F^3(k-1) (6)

F^3k-1＝W×F^3(k-2) (7)

In the formula: and k is the iteration number of the message path acquisition algorithm.

9. The automatic defect positioning method for relay protection system level test according to claim 7, wherein: and performing defect positioning operation according to the result information of the relay protection test as follows: when the relay protection test of the process layer network is carried out, the test equipment sends SV messages to the relay protection system, and then whether the tested function is normal is judged according to the returned GOOSE messages.

10. The method for automatically positioning the defects in the relay protection system level test according to claim 9, wherein: assuming that only one single-point defect exists in the layer network in the same time process, by analyzing the alarm information of message broken link generated in the device test, if m message links are affected and the total number of the message links is n, the defect positioning matrix G can be obtained by the formula (8)