Centralized protection method and device for different operation modes of new energy power distribution network

Abstract

The invention discloses a centralized protection method and device for different operation modes of a new energy power distribution network, and the method comprises the steps: obtaining the on-off state information of a circuit breaker at an outlet of a transformer substation, judging the operation state of the power distribution network, and obtaining an operation state discrimination result of the power distribution network; constructing a network topology matrix D of the power distribution network; obtaining current state information of a power distribution switch monitoring terminal of each node in the power distribution network, judging whether a fault current is detected and whether the flow direction of the fault current is the same as the positive direction of the power distribution network, and obtaining a judgment result of the node; constructing a fault information matrix F; constructing a fault judgment matrix Z; and analyzing the fault judgment matrix Z by adopting a preset fault identification strategy to obtain a fault section judgment result. Based on the graph theory, the centralized protection method integrating local and regional multi-source information is provided with the direction criterion as the core, and accurate and reliable fault identification under the influence of high-proportion new energy access of the power distribution network and flexible change of the operation state is achieved.

Description

Technical Field

[0001] The present invention relates to the field of relay protection for AC distribution networks with a high proportion of renewable energy access, and in particular to a centralized protection method and device for different operation modes of renewable energy distribution networks, and in particular to a centralized protection method and device suitable for renewable energy distribution networks and taking into account on / off-grid switching of distribution networks. Background Art

[0002] Under the background of the construction of new power systems, the power supply characteristics of the distribution network will gradually change from being dominated by synchronous power supplies to being dominated by distributed photovoltaic and other new energy sources, and its structure will gradually evolve into a new form of highly power electronic, flexible and interconnected based on the existing distribution network. However, the fault response characteristics of distributed new energy and other power electronic equipment are very different from those of synchronous power supplies, and the uncertainty of their location and form of access to the distribution network. The distribution network is no longer a linear system in the traditional sense, and the traditional protection principle based on the steady-state quantity of power frequency is difficult to apply. In addition, with the increasing proportion of inverter-type distributed power sources represented by new energy generation connected to the distribution network, the distribution of current and short-circuit current in the distribution network has undergone fundamental changes, which has also affected the reliable operation of the original protection and control devices in the distribution network. The distribution network has different flexible operating modes, and there are grid-connected and off-grid operating states, which makes the fault characteristics of the distribution network more complicated. The traditional current protection principle that is pre-set according to the most serious fault situation and has a fixed action value is difficult to quickly and accurately remove the fault.

[0003] Current differential protection can reliably reflect faults within the distribution network line area, is less affected by the system operation mode, has high sensitivity, and has the advantages of absolute selectivity. It is an effective way to solve the problem of distributed new energy access affecting the applicability of traditional protection. Based on the differential protection principle of 5G communication, from the perspective of current differential protection at both ends, each terminal protection device collects the phase current and zero-sequence current of the TA (current transformer) on both sides, and calculates the differential current and braking current of the protected line respectively, and interacts in real time through the 5G network. When a fault occurs within the area, the current differential protection logic at both ends acts separately, and the protection action exits to realize the application of current differential protection in the distribution network. However, according to the 5G differential principle, this protection method needs to rely on data synchronization at both ends of the line to realize fault identification, and the reliability of the differential protection action has strict requirements on the signal synchronization accuracy.

[0004] Distribution / microgrid terminals are numerous and widespread, and large-scale deployment of timing equipment is labor-intensive and has high requirements for the operating environment. The current signal timing synchronization method still cannot achieve large-scale application of current differential protection in distribution networks.

[0005] Therefore, in response to this situation, it is necessary to study new distribution network line protection solutions that are suitable for different operating modes of new energy distribution networks. Summary of the invention

[0006] Based on this, it is necessary to provide a centralized protection method and device for different operating modes of the new energy distribution network in response to the above technical problems.

[0007] According to one aspect of the present invention, a centralized protection method for different operation modes of a new energy distribution network is provided, including: obtaining circuit breaker disconnection status information at a transformer substation outlet, and judging the operation status of the distribution network based on the circuit breaker disconnection status information to obtain an operation status judgment result of the distribution network; constructing a distribution network network topology matrix D based on the operation status judgment result of the distribution network; obtaining current status information of a distribution switch monitoring terminal of each node in the distribution network, and judging whether a fault current is detected and whether the flow direction of the fault current is the same as the positive direction of the distribution network based on the current status information to obtain a judgment result of the node; constructing a fault information matrix F based on the judgment result of the node; constructing a fault judgment matrix Z based on the distribution network network topology matrix D and the fault information matrix F; and analyzing the fault judgment matrix Z according to the operation status judgment result of the distribution network using a preset fault identification strategy to obtain a fault section judgment result.

[0008] In some optional implementations of some embodiments, the circuit breaker opening status data at the substation outlet is obtained, and the operating status of the distribution network is judged based on the circuit breaker opening status data to obtain the operating status judgment result of the distribution network, including: obtaining the circuit breaker opening status information at the substation outlet, and judging the operating status of the distribution network. If the circuit breaker opening status information is in a closed state, the distribution network operates in a grid-connected state, otherwise the distribution network operates in an off-grid state.

[0009] In some optional implementations of some embodiments, the construction of the distribution network network topology matrix D based on the operation status judgment result of the distribution network includes: if the distribution network operates in a grid-connected state, setting the direction of network power flowing from the main power supply to each distributed power supply and the end of the line as the positive direction, and defining the first node flowing in the positive direction in each section as the parent node, and the remaining nodes as child nodes, to construct an equivalent topology diagram of the centralized protection scheme of the distribution network in the grid-connected state; based on the equivalent topology diagram of the centralized protection scheme of the distribution network in the grid-connected state, constructing an n×n network topology matrix D1=(d ij ), where n is the number of nodes. When node i and node j are the parent and child nodes of the same segment, respectively, and they are forward connected, then define d ij =1, otherwise define d ij=0; for a T-connected section, when there is 1 parent node and 2 child nodes, the connection relationship between the child nodes of the T-connected section is defined as 0; if the distribution network operates in an off-grid state, an equivalent topological diagram of a centralized protection scheme for the distribution network in an off-grid state is constructed, and based on the constructed equivalent topological diagram of a centralized protection scheme for the distribution network in an off-grid state, the network topological matrix D1 is switched to generate a network topological matrix D2; the construction of the distribution network topological matrix D is completed according to the network topological matrix D1 and the network topological matrix D2, and the distribution network topological matrix D is an asymmetric matrix with diagonal elements of 0 and high sparsity.

[0010] In some optional implementations of some embodiments, the current status information of the distribution switch monitoring terminal of each node in the distribution network is obtained, and based on the current status information, it is determined whether a fault current is detected and whether the direction of the fault current is the same as the positive direction of the distribution network to obtain a judgment result of the node, including: obtaining the current status information of the distribution switch monitoring terminal of each node in the distribution network, wherein the current status information includes current information and current direction information, and judging whether a fault current is detected based on the current information; if the current information shows that no fault current is detected, a judgment result is obtained that no fault current exists at the node; if the current information shows that a fault current is detected, and based on the current direction information, whether the direction of the fault current is the same as the positive direction of the distribution network is further judged; if they are the same, a judgment result is obtained that a forward fault current flows through the node; if they are not the same, a judgment result is obtained that a reverse fault current flows through the node.

[0011] In some optional implementations of some embodiments, the construction of the fault information matrix F based on the node identification results includes: constructing an n×n type fault information matrix F uploaded by the node based on the node identification results = (f ii ), where f ii The values ​​are 1, 0, and -1, which respectively represent the judgment result that the forward fault current flows through node i, the judgment result that there is no fault current in node i, the judgment result that the reverse fault current flows through node i, and the judgment result of the node. ii The corresponding logic signal is sent to the master station.

[0012] In some optional implementations of some embodiments, obtaining the fault judgment matrix Z based on the distribution network topology matrix D and the fault information matrix F includes: completing the construction of the fault judgment matrix Z according to the distribution network topology matrix D and the fault information matrix F, wherein the fault judgment matrix Z=D+F.

[0013] In some optional implementations of some embodiments, the operation status of the distribution network is judged by using a preset fault identification strategy to analyze the fault determination matrix Z to obtain a fault section judgment result, including: presetting three fault identification strategies, wherein the first fault identification strategy: if Z ii =1 and Z ij = 1, all j have Z jj =0 or -1, where j≠i, and the feeder section between node i and node j is a common section, then the fault occurs in the feeder section formed by node i and node j; The second fault identification strategy: If Z ii =1 and Z ij = 1, all j have Z jj =0 or -1, where j≠i, and when the feeder section between node i and node j is a T-connected section, since the T-connected section has two child nodes j1 and j2, if the positioning results obtained by the parent node and the two child nodes according to the first fault identification strategy are the same, then the fault occurs in the T-connected section, otherwise the T-connected section has no fault; the third fault identification strategy: if the feeder section where node i is located is the terminal section, then it satisfies: Z ii =1, Z ij =0, where i≠j; according to the operation status judgment result of the distribution network, the network topology matrix D1 or the network topology matrix D2 is determined, and based on the network topology matrix D1 or the network topology matrix D2 and the fault information matrix F, the final fault judgment matrix Z is obtained, and the three preset fault identification strategies are adopted to analyze the fault judgment matrix Z to obtain the fault section judgment result.

[0014] According to a second aspect of the present invention, a centralized protection device for different operation modes of a new energy distribution network is provided, including: a first discrimination module, used to obtain the circuit breaker disconnection state information at the transformer substation outlet, and judge the operation state of the distribution network based on the circuit breaker disconnection state information to obtain the operation state discrimination result of the distribution network; a distribution network network topology matrix construction module, used to construct the distribution network network topology matrix D based on the operation state discrimination result of the distribution network; a second discrimination module, used to obtain the current state information of the distribution switch monitoring terminal of each node in the distribution network, and judge whether a fault current is detected and whether the flow direction of the fault current is the same as the positive direction of the distribution network based on the current state information, to obtain the discrimination result of the node; a fault information matrix construction module, used to construct a fault information matrix F based on the discrimination result of the node; a fault judgment matrix construction module, used to construct a fault judgment matrix Z based on the distribution network network topology matrix D and the fault information matrix F; a fault section analysis module, used to analyze the fault judgment matrix Z according to the operation state discrimination result of the distribution network, using a preset fault identification strategy, to obtain the fault section judgment result.

[0015] According to a third aspect of the present invention, an electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0016] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium storing a computer program, wherein the computer program implements the steps of the above method when executed by a processor.

[0017] The advantages and beneficial effects of the present invention are as follows: the present application provides a centralized protection method and device for different operating modes of a new energy distribution network. The method constructs an equivalent topological diagram of an integrated protection scheme for parallel / disconnected operation of the distribution network by detecting the disconnection state of the substation outlet circuit breaker, and constructs a network topology matrix of the distribution network. At the same time, according to the judgment results of the nodes, a fault information matrix F is constructed, and then a fault judgment matrix Z is obtained. A preset fault identification strategy is adopted to analyze the fault judgment matrix Z, so as to determine the fault section, which can realize fault identification of different operating states in the distribution network and rapid and reliable positioning of faults. In addition, based on graph theory and with direction criterion as the core, the present application proposes a centralized protection method that integrates local and regional multi-source information, which realizes accurate and reliable identification of faults under the influence of high-proportion new energy access and flexible changes in operating states in the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of an AC power distribution network to which photovoltaic power is connected in an embodiment of the present invention.

[0019] Figure 2 The flowchart is a centralized protection method for different operation modes of a new energy distribution network in an embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of an equivalent topology diagram of a centralized protection scheme for a distribution network in a grid-connected state in an embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of an equivalent topology diagram of a centralized protection scheme for a distribution network in an off-grid state in an embodiment of the present invention.

[0022] Figure 5 Schematic diagram of a centralized protection device for different operation modes of a new energy distribution network in an embodiment of the present invention.

[0023] Figure 6 Schematic diagram of an electronic device in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through specific implementation methods in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] Embodiment 1

[0026] Factors such as the AC distribution network with a high proportion of new energy access, the new energy access capacity, and the access location will affect the applicability of traditional current protection; and the new energy distribution network has flexible operation modes, and there are grid-connected and off-grid operation states. The traditional current protection principle based on pre-setting and fixed action values ​​cannot be reliably applied. In other words, the protection plan for the new energy distribution network needs to consider not only the impact of a high proportion of new energy access, but also the impact of different operating states of the distribution network. In view of this, based on graph theory and with direction criteria as the core, a centralized protection method that integrates local and regional multi-source information is proposed for line faults in the AC distribution network with new energy access, so as to achieve accurate and selective fault identification.

[0027] Compared with the traditional radial distribution network, the power flow in the distribution network is complex, which further increases the difficulty of identifying the fault section. Therefore, in view of the high penetration rate of distributed power sources in the distribution network, the changeable operation mode, and the large difference between the various measurements under the fault state and the traditional distribution network, the relevant knowledge of graph theory can be applied to simply describe the structure of the distribution network as a graph of the connection relationship between nodes and segments. Among them, the nodes can include disconnectors, circuit breakers, and section switches, and the segments are the distribution lines connecting the above devices.

[0028] The present invention Figure 1 The 9-node distribution network topology shown in the figure is used as an example to illustrate the Figure 2 , the method specifically includes the following steps.

[0029] S1: Obtain the circuit breaker disconnection status information at the substation outlet, and judge the operation status of the distribution network based on the circuit breaker disconnection status information to obtain the operation status judgment result of the distribution network.

[0030] In some embodiments, the circuit breaker opening status data at the substation outlet is obtained, and the operating status of the distribution network is judged based on the circuit breaker opening status data to obtain the operating status judgment result of the distribution network, including: obtaining the circuit breaker opening status information at the substation outlet, and judging the operating status of the distribution network. If the circuit breaker opening status information is in a closed state, the distribution network operates in a grid-connected state, otherwise the distribution network operates in an off-grid state.

[0031] S2: Based on the results of the distribution network operation status judgment, the distribution network topology matrix D is constructed.

[0032] In some embodiments, the construction of the distribution network network topology matrix D based on the operation state judgment result of the distribution network includes: if the distribution network operates in the grid-connected state, setting the direction of network power flowing from the main power supply to each distributed power supply and the end of the line as the positive direction, and defining the first node flowing in the positive direction in each section as the parent node, and the remaining nodes as child nodes, to construct an equivalent topology diagram of the centralized protection scheme of the distribution network in the grid-connected state; based on the equivalent topology diagram of the centralized protection scheme of the distribution network in the grid-connected state, constructing an n×n type network topology matrix D1=(d ij ), where n is the number of nodes. When node i and node j are the parent and child nodes of the same segment, respectively, and they are forward connected, then define d ij =1, otherwise define d ij =0; for a T-connected section, when there is 1 parent node and 2 child nodes, the connection relationship between the child nodes of the T-connected section is defined as 0; if the distribution network operates in an off-grid state, an equivalent topological diagram of a centralized protection scheme for the distribution network in an off-grid state is constructed, and based on the constructed equivalent topological diagram of a centralized protection scheme for the distribution network in an off-grid state, the network topological matrix D1 is switched to generate a network topological matrix D2; the construction of the distribution network topological matrix D is completed according to the network topological matrix D1 and the network topological matrix D2, and the distribution network topological matrix D is an asymmetric matrix with diagonal elements of 0 and high sparsity.

[0033] In some embodiments, if the distribution network is running in a grid-connected state, the direction of network power flowing from the main power source to each distributed generator (DG) and the end of the line is first set as the positive direction, and the first node flowing in the positive direction in each section is defined as the parent node, and the rest are child nodes, to construct an equivalent topological diagram of the centralized protection scheme of the distribution network in the grid-connected state, as shown in the attached figure. Figure 3 As shown in the attached Figure 3 In the figure, the arrow direction is the positive direction of the set network power (i.e., the direction in which the network power flows from the main power source to each distributed generator (DG) and the end of the line), S represents the main power source, 1-9 represents the node number, (1)-(9) represents the segment number, and PV represents photovoltaic. After constructing the equivalent topological diagram of the centralized protection scheme of the distribution network in the grid-connected state, an n×n network topological matrix D=(d ij ), n is the number of nodes. The network topology matrix is ​​essentially an asymmetric adjacency matrix that describes the connection relationship of all nodes in the distribution network. When node i and node j (i≠j) are the parent and child nodes of the same segment respectively, and the two are forward connected, then define d ij =1, otherwise define d ij= 0. For the T-connected section, there is 1 parent node and 2 child nodes, and the connection relationship between the child nodes is defined as 0. The network topology matrix in the grid-connected state is specifically:

[0034]

[0035] In some embodiments, if the distribution network is running in a grid-connected state, an equivalent topological diagram of a centralized protection scheme for the distribution network in an off-grid state is constructed, as shown in the attached figure. Figure 4 As shown, according to the attached Figure 4 The equivalent topology diagram of the centralized protection scheme of the distribution network in the off-grid state shown in the figure switches the network topology matrix to obtain the network topology matrix in the off-grid state, which is specifically:

[0036]

[0037] The construction of the distribution network topology matrix D is completed according to equations (1) and (2), and the distribution network topology matrix D is an asymmetric matrix with diagonal elements of 0 and high sparsity.

[0038] S3: Obtain the current status information of the distribution switch monitoring terminal of each node in the distribution network, and determine whether a fault current is detected and whether the direction of the fault current is the same as the positive direction of the distribution network based on the current status information, and obtain the node judgment result.

[0039] In some embodiments, current status information of distribution switch monitoring terminals of each node in the distribution network is obtained, and based on the current status information, it is determined whether a fault current is detected and whether the direction of the fault current is the same as the positive direction of the distribution network to obtain a judgment result of the node, including: obtaining current status information of distribution switch monitoring terminals of each node in the distribution network, wherein the current status information includes current information and current flow direction information, and judging whether a fault current is detected based on the current information; if the current information shows that no fault current is detected, a judgment result is obtained that no fault current exists at the node; if the current information shows that a fault current is detected, and based on the current flow direction information, it is further determined whether the direction of the fault current is the same as the positive direction of the distribution network; if they are the same, a judgment result is obtained that a forward fault current flows through the node; if they are not the same, a judgment result is obtained that a reverse fault current flows through the node.

[0040] In some embodiments, after a fault occurs in the distribution network, the power flow direction will change. The distribution switch monitoring terminal (Feeder Terminal Unit, FTU) installed at each node collects current status information, where the current status information includes current information and current flow direction information. It is determined whether a fault current is detected based on the current information and whether the direction of the fault current is the same as the positive direction of the distribution network based on the current flow direction information, and three logic signals of "1, 0, -1" are uploaded to the master station.

[0041] S4: Based on the node identification results, construct the fault information matrix F.

[0042] In some embodiments, based on the node identification results, constructing a fault information matrix F, including: based on the node identification results, constructing an n×n type fault information matrix F uploaded by the node = (f ii ), where f ii The values ​​are 1, 0, and -1, which respectively represent the judgment result that the forward fault current flows through node i, the judgment result that there is no fault current in node i, the judgment result that the reverse fault current flows through node i, and the judgment result of the node. ii The corresponding logic signal is sent to the master station.

[0043] In some embodiments, the n×n fault information matrix F uploaded by the established nodes is (f ii ), where f ii The values ​​are 1, 0, and -1, which respectively indicate that a forward fault current flows through node i, that there is no fault current in node i, and that a reverse fault current flows through node i.

[0044] In some embodiments, the values ​​of the elements on the diagonal of the fault information matrix F involved in the present application reflect the action of the direction criterion, that is, if the i-th node is determined to be a positive direction fault, the i-th row and i-th column element is "1", that is, f ii =1; if the i-th node is judged to be a reverse fault, the i-th row and i-th column element is "-1", that is, f ii = -1; if the i-th node has no fault, the i-th row and i-th column element is "0", that is, f ii =0.

[0045] S5: Based on the distribution network topology matrix D and the fault information matrix F, a fault judgment matrix Z is constructed.

[0046] In some embodiments, based on the distribution network topology matrix D and the fault information matrix F, a fault determination matrix Z is obtained, including: constructing the fault determination matrix Z according to the distribution network topology matrix D and the fault information matrix F, wherein the fault determination matrix Z=D+F.

[0047] S6: According to the operation status judgment result of the distribution network, a preset fault identification strategy is adopted to analyze the fault judgment matrix Z to obtain the fault section judgment result.

[0048] In some embodiments, according to the operation status judgment result of the distribution network, a preset fault identification strategy is adopted to analyze the fault judgment matrix Z to obtain the fault section judgment result, including: presetting three fault identification strategies, wherein the first fault identification strategy: if Z ii =1 and Zij = 1, all j have Z jj =0 or -1, where j≠i, and the feeder section between node i and node j is a common section, then the fault occurs in the feeder section formed by node i and node j; The second fault identification strategy: If Z ii =1 and Z ij = 1, all j have Z jj =0 or -1, where j≠i, and when the feeder section between node i and node j is a T-connected section, since the T-connected section has two child nodes j1 and j2, if the positioning results obtained by the parent node and the two child nodes according to the first fault identification strategy are the same, then the fault occurs in the T-connected section, otherwise the T-connected section has no fault; the third fault identification strategy: if the feeder section where node i is located is the terminal section, then it satisfies: Z ii =1, Z ij =0, where i≠j; according to the operation status judgment result of the distribution network, the network topology matrix D1 or the network topology matrix D2 is determined, and based on the network topology matrix D1 or the network topology matrix D2 and the fault information matrix F, the final fault judgment matrix Z is obtained, and the three preset fault identification strategies are adopted to analyze the fault judgment matrix Z to obtain the fault section judgment result.

[0049] In some embodiments, in order to facilitate the location of faults in different feeder sections, the present application divides the feeder sections into T-sections, end sections and common sections, forming the following fault identification strategy.

[0050] (1) If Z ii =1 and Z ij = 1, all j have Z jj =0 or -1 (j≠i), the criterion condition is met, and the feeder section between node i and node j is a common section, then the fault occurs in the feeder section formed by node i and node j.

[0051] (2) When the conditions of the first fault identification strategy are met and the feeder section between node i and node j is a T-connected section, since the T-connected section has two child nodes j1 and j2, if the positioning results obtained by the parent node and the two child nodes according to the fault identification strategy are the same, then the fault occurs in the T-connected section; otherwise, the T-connected section has no fault.

[0052] (3) If the feeder section where node i is located is the terminal section, then: Z ii =1, Z ij =0(i≠j).

[0053] Furthermore, based on the parallel / disconnected operation status of the distribution network, the specific D1 / D2 to be adopted is determined in order to obtain the final fault judgment matrix Z. The above three fault identification strategies are used to analyze the elements in the determined fault judgment matrix Z to determine the fault section.

[0054] For example, for the distribution network in grid-connected operation, when section (6) fails, the fault information matrix F is:

[0055]

[0056] Furthermore, based on the grid-connected operation state of the distribution network, the network topology matrix D1 under the grid-connected state is determined, as shown in formula (1), and combined with the fault information matrix F, as shown in formula (3), the final fault judgment matrix Z is obtained, and the elements in the fault judgment matrix Z are analyzed using the preset fault identification strategy, where Z 66 =1, Z 68 =1, Z 88 = -1, and there is a T-connected section between node 6 and node 8, then the first fault identification strategy is used to determine that the section (6) is faulty. Since section (6) is a T-connected section, the matrix elements of the parent node 6 of section (6) and another child node 7 are further determined, namely: Z 66 =1, Z 67 =1, Z 77 =-1. The fault condition is met and the fault information is not contradictory, so it is determined that section (6) is faulty. The above centralized protection method is simple in principle and can avoid the matrix multiplication process, so as to reduce the calculation complexity of the matrix and save calculation time.

[0057] Embodiment 2

[0058] Based on the above-mentioned embodiment 1, this embodiment provides a centralized protection device 200 for different operation modes of a new energy distribution network. Figure 5 , used to implement the steps of the centralized protection method for different operation modes of the new energy distribution network described in the above-mentioned embodiment 1, the device mainly includes: a first judgment module 201, a distribution network topology matrix construction module 202, a second judgment module 203, a fault information matrix construction module 204, a fault judgment matrix construction module 205 and a fault section analysis module 206.

[0059] In some embodiments, the first determination module 201 is used to obtain the circuit breaker disconnection status information at the transformer substation outlet, and determine the operation status of the distribution network based on the circuit breaker disconnection status information to obtain the operation status determination result of the distribution network.

[0060] In some embodiments, the distribution network topology matrix construction module 202 is used to construct a distribution network topology matrix D based on the operation status determination result of the distribution network.

[0061] In some embodiments, the second judgment module 203 is used to obtain the current status information of the distribution switch monitoring terminal of each node in the distribution network, and determine whether a fault current is detected and whether the direction of the fault current is the same as the positive direction of the distribution network based on the current status information to obtain a judgment result of the node.

[0062] In some embodiments, the fault information matrix construction module 204 is used to construct a fault information matrix F based on the determination results of the nodes.

[0063] In some embodiments, the fault determination matrix construction module 205 is used to construct a fault determination matrix Z based on the distribution network topology matrix D and the fault information matrix F.

[0064] In some embodiments, the fault section analysis module is used to analyze the fault determination matrix Z according to the operation status determination result of the distribution network and adopt a preset fault identification strategy to obtain the fault section determination result 206.

[0065] Embodiment 3

[0066] This embodiment further provides an electronic device based on the above embodiment 1. Figure 6 , Figure 6 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0067] like Figure 6 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processor, etc.) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage device 308 into a random access memory (RAM) 303. In RAM 303, various programs and data required for the operation of the electronic device are also stored. The processing device 301, ROM 302, and RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0068] Typically, the following devices may be connected to the I / O interface 305: an input device 306 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, etc., an output device 307 including, for example, a liquid crystal display (LCD), a speaker, etc., a storage device 308 including, for example, a magnetic tape, a hard disk, etc., and a communication device 309. The communication device 309 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Figure 6 An electronic device having various devices is shown, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead. Figure 6 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0069] In particular, according to some embodiments of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, some embodiments of the present disclosure include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In some such embodiments, the computer program can be downloaded and installed from the network through the communication device 309, or installed from the storage device 308, or installed from the ROM 302. When the computer program is executed by the processing device 301, the above-mentioned functions defined in the method of some embodiments of the present disclosure are executed.

[0070] Embodiment 4

[0071] Based on the above-mentioned embodiment 1, this embodiment further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the above-mentioned method are implemented.

[0072] It should be noted that the computer-readable medium in some embodiments of the present disclosure may be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In some embodiments of the present disclosure, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In some embodiments of the present disclosure, the computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0073] In this embodiment, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperTextTransferProtocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0074] The computer-readable medium may be included in the device, or may exist independently without being installed in the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: obtains training data, converts the training data into initial data; determines an initial rule base based on the initial data, and optimizes the parameters of the initial rule base to obtain a target rule base; calculates the rules in the target rule base according to a preset activation weight calculation formula to obtain activation weights; determines abnormal information according to the test data and the activation weights.

[0075] Computer program code for performing the operations of some embodiments of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0076] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0077] The units described in some embodiments of the present disclosure may be implemented by software or hardware. The units described may also be provided in a processor, for example, may be described as: a processor including a data acquisition unit, a rule determination unit, a weight calculation unit, and an anomaly determination unit. The names of these units do not, in some cases, constitute limitations on the units themselves, for example, the data acquisition unit may also be described as a "unit for acquiring training data".

[0078] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), etc.

[0079] Obviously, it should be understood by those skilled in the art that the above-mentioned various steps of the present invention can be performed in a manner different from the present invention, and the simulation method and experimental equipment include but are not limited to the above description. The above-mentioned various steps of the present invention can be performed in an order different from that here in some cases, and the steps shown or described above can be performed separately. Therefore, the present invention is not limited to any specific combination of hardware and software.

[0080] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A centralized protection method for different operation modes of a new energy distribution network, characterized in that: include: Obtaining the circuit breaker disconnection status information at the substation outlet, and judging the operation status of the distribution network based on the circuit breaker disconnection status information, to obtain the operation status judgment result of the distribution network; Based on the results of the distribution network operation status determination, the distribution network topology matrix D is constructed; Obtain the current status information of the distribution switch monitoring terminal of each node in the distribution network, and determine whether a fault current is detected and whether the direction of the fault current is the same as the positive direction of the distribution network based on the current status information, and obtain the node judgment result; Based on the node identification results, the fault information matrix F is constructed; Based on the distribution network topology matrix D and the fault information matrix F, a fault judgment matrix Z is constructed; According to the results of the operation status judgment of the distribution network, the preset fault identification strategy is adopted to analyze the fault judgment matrix Z and obtain the fault section judgment result.

2. The centralized protection method for different operation modes of the new energy distribution network according to claim 1 is characterized in that: The step of obtaining the circuit breaker disconnection status data at the transformer substation outlet, and judging the operation status of the distribution network based on the circuit breaker disconnection status data to obtain the operation status judgment result of the distribution network includes: The circuit breaker disconnection status information at the substation outlet is obtained to judge the operation status of the distribution network. If the circuit breaker disconnection status information is in a closed state, the distribution network is operating in a grid-connected state, otherwise the distribution network is operating in an off-grid state.

3. The centralized protection method for different operation modes of the new energy distribution network according to claim 2 is characterized in that: The distribution network topology matrix D is constructed based on the operation status determination result of the distribution network, including: If the distribution network is running in the grid-connected state, the direction of network power flowing from the main power source to each distributed power source and the end of the line is set as the positive direction, and the first node flowing in the positive direction in each section is defined as the parent node, and the rest are child nodes, to construct an equivalent topological diagram of the centralized protection scheme of the distribution network in the grid-connected state; Based on the equivalent topological diagram of the centralized protection scheme of the distribution network in the grid-connected state, an n×n network topological matrix D1=(d ij ), where n is the number of nodes. When node i and node j are the parent and child nodes of the same segment, respectively, and they are forward connected, then define d ij = 1, otherwise define d ij =0; for a T-junction segment with 1 parent node and 2 child nodes, the connection relationship between the child nodes of the T-junction segment is defined as 0; If the distribution network is operating in an off-grid state, an equivalent topology diagram of a centralized protection scheme for the distribution network in an off-grid state is constructed, and based on the constructed equivalent topology diagram of a centralized protection scheme for the distribution network in an off-grid state, the network topology matrix D1 is switched to generate a network topology matrix D2; The construction of the distribution network topology matrix D is completed according to the network topology matrix D1 and the network topology matrix D2. The distribution network topology matrix D is an asymmetric matrix with diagonal elements of 0 and high sparsity.

4. The centralized protection method for different operation modes of the new energy distribution network according to claim 3 is characterized in that: The current status information of the distribution switch monitoring terminal of each node in the distribution network is obtained, and based on the current status information, it is determined whether a fault current is detected and whether the flow direction of the fault current is the same as the positive direction of the distribution network to obtain the node determination result, including: The current status information of the distribution switch monitoring terminal of each node in the distribution network is obtained, wherein the current status information includes current information and current flow direction information, and whether a fault current is detected is determined based on the current information. If the current information shows that a fault current is not detected, a judgment result is obtained that no fault current exists at the node. If the current information shows that a fault current is detected, and based on the current flow direction information, whether the flow direction of the fault current is the same as the positive direction of the distribution network is further determined. If they are the same, a judgment result is obtained that a forward fault current flows through the node. If they are not the same, a judgment result is obtained that a reverse fault current flows through the node.

5. The centralized protection method for different operation modes of the new energy distribution network according to claim 4 is characterized in that: The fault information matrix F is constructed based on the node identification results, including: Based on the node identification results, the n×n fault information matrix F=(f ii ), where f ii The values ​​are 1, 0, and -1, which respectively represent the judgment result that the forward fault current flows through node i, the judgment result that there is no fault current in node i, the judgment result that the reverse fault current flows through node i, and the judgment result of the node. ii The corresponding logic signal is sent to the master station.

6. The centralized protection method for different operation modes of the new energy distribution network according to claim 5 is characterized in that: The fault determination matrix Z is obtained based on the distribution network topology matrix D and the fault information matrix F, including: The fault determination matrix Z is constructed according to the distribution network topology matrix D and the fault information matrix F, wherein the fault determination matrix Z=D+F.

7. The centralized protection method for different operation modes of the new energy distribution network according to claim 6 is characterized in that: According to the operation status judgment result of the distribution network, a preset fault identification strategy is adopted to analyze the fault judgment matrix Z to obtain the fault section judgment result, including: Three fault identification strategies are preset. The first fault identification strategy: if Z ii =1 and Z ij =1, all j have Z jj =0 or -1, where j≠i, and the feeder section between node i and node j is a common section, then the fault occurs in the feeder section formed by node i and node j; The second fault identification strategy: If Z ii =1 and Z ij =1, all j have Z jj =0 or -1, where j≠i, and when the feeder section between node i and node j is a T-connected section, since the T-connected section has two child nodes j1 and j2, if the positioning results obtained by the parent node and the two child nodes according to the first fault identification strategy are the same, then the fault occurs in the T-connected section, otherwise the T-connected section has no fault; the third fault identification strategy: if the feeder section where node i is located is the terminal section, then it satisfies: Z ii =1,Z ij =0, where i≠j; According to the results of the operation status judgment of the distribution network, the network topology matrix D1 or the network topology matrix D2 is determined, and based on the network topology matrix D1 or the network topology matrix D2 and the fault information matrix F, the final fault judgment matrix Z is obtained. The three preset fault identification strategies are used to analyze the fault judgment matrix Z to obtain the fault section judgment result.

8. Centralized protection device for different operation modes of new energy distribution network, characterized in that: include: The first determination module is used to obtain the circuit breaker disconnection status information at the substation outlet, and determine the operation status of the distribution network based on the circuit breaker disconnection status information to obtain the operation status determination result of the distribution network; A distribution network topology matrix construction module is used to construct a distribution network topology matrix D based on the operation status judgment result of the distribution network; The second discrimination module is used to obtain the current status information of the distribution switch monitoring terminal of each node in the distribution network, and judge whether a fault current is detected and whether the flow direction of the fault current is the same as the positive direction of the distribution network based on the current status information, so as to obtain the discrimination result of the node; A fault information matrix construction module is used to construct a fault information matrix F based on the node discrimination results; A fault determination matrix building module is used to build a fault determination matrix Z based on the distribution network topology matrix D and the fault information matrix F; The fault section analysis module is used to analyze the fault judgment matrix Z according to the operation status judgment result of the distribution network, adopt a preset fault identification strategy, and obtain the fault section judgment result.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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