Method for automatically identifying CT disconnection through multiple buses and relay protection device

Abstract

The invention discloses a method for automatically identifying CT disconnection by multiple buses and a relay protection device. The method comprises the following steps: acquiring data in a multi-dimensional interval data model of each interval in a station; and creating a bus-interval two-dimensional cell graph according to data of the multi-dimensional interval data model, performing normalized bus section processing on cells in the two-dimensional cell graph, identifying the isolation partitions in the station, and calculating bus differential protection current of the isolation partitions in the station and differential current of each bus section in the partitions so as to identify the CT disconnection condition. According to the method, not only can various CT broken line types faced by the relay protection device be effectively identified, but also the specific position of the CT broken line can be accurately positioned, and the CT broken line judgment accuracy of the relay protection device in a complex bus structure is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of relay protection of electric power systems, and relates to a method for automatically identifying CT disconnection of multiple buses and a relay protection device. Background Art

[0002] Relay protection devices are an important part of the power system, and busbars are important equipment in substations. When a CT (current transformer) is broken in the substation, it is necessary to accurately identify it and remind the operation and maintenance personnel to check the secondary circuit as soon as possible to reduce the occurrence of false operation and refusal to operate accidents caused by CT breakage.

[0003] The traditional bus differential method provides different CT disconnection judgment methods according to the corresponding main connection. The CT disconnection judgment criteria for double bus, one and a half main connection, and double bus single segment are different and limited to three bus sections. The protection software version changes with the change of the main connection method. At present, there are many types of main connections in the substation, and the bus protection software cannot identify the CT disconnection anomaly in the case of multiple busbars. The traditional version can no longer meet the complex on-site scenarios. Therefore, a multi-bus automatic CT disconnection recognition technology is urgently needed. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a method for automatically identifying CT disconnection in multiple busbars and a relay protection device, so as to improve the accuracy of CT disconnection identification of the relay protection device in a complex busbar structure.

[0005] The present invention adopts the following technical solution.

[0006] The first aspect of the present invention provides a method for automatically identifying CT disconnection in multiple buses, comprising:

[0007] Obtaining data in a multi-dimensional interval data model for each interval within the station;

[0008] A busbar-interval two-dimensional cell map is created based on the data of the multidimensional interval data model, and the cells in the two-dimensional cell map are normalized into bus sections to identify the isolated partitions within the station. The busbar differential protection current of the isolated partition within the station and the differential current of each bus section in the partition are calculated to identify CT line breaks.

[0009] Preferably, the data in the multi-dimensional interval data model includes interval description, switch status, and interval current;

[0010] The interval description is preset, including the interval serial number, interval name, interval nature, and the number of bus sections N;

[0011] The switch state is the switch state of the interval connected to the multi-section busbar, which is divided into a closed state and an open state;

[0012] The interval current includes the A-phase current, B-phase current, C-phase current and zero-sequence current of the secondary circuit where the interval is located.

[0013] Preferably, the interval serial number is a customized different numerical value; the interval name adopts the same scheduling interval description or a customized description; the interval properties are divided into branches and busbars with current access; the number of busbar sections is the number of busbar sections actually put into use in the main connection of the current station.

[0014] Preferably, the bus-interval two-dimensional cell map is created according to the data of the multidimensional interval data model, and the cells in the two-dimensional cell map are normalized into bus segments, the isolation partitions within the station are identified, and the bus differential protection current of the isolation partition within the station and the differential current of each bus segment in the partition are calculated to identify the CT disconnection situation, which specifically includes:

[0015] According to the number of busbar sections N and the number of bays of the main wiring in the station M, a busbar-bay two-dimensional cell map is created for bays of different properties, where the horizontal direction is the busbar and the vertical direction is the bay;

[0016] According to the switch status of the bay and the multi-section busbar, the connection status of the bay and different busbar sections is identified, and the cells in the two-dimensional cell map are filled according to the connection status. If connected, the corresponding cell is marked, and if not connected, the corresponding cell is not marked;

[0017] Based on the interval properties, the cells in the two-dimensional cell map are processed into normalized bus segments, and the isolated partitions within the station are identified;

[0018] Calculate the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition respectively;

[0019] The CT disconnection situation is identified based on the bus differential protection current of the isolated partition within the station and the differential current of each bus section within the partition.

[0020] Preferably, after filling the cells in the two-dimensional cell map according to the attachment situation, it is checked whether there is a situation where different branch intervals are attached to the same bus segment. If so, all other bus segments attached to the branch are merged into the same type of bus segments, and the relevant branch intervals are attached to all such bus segments to maximize cell merging.

[0021] Preferably, based on the interval property, the cells in the two-dimensional cell map are processed into a normalized bus segment, and the isolated partitions within the station are identified, specifically:

[0022] For the interval of the branch with current access, the bus segments where the marked cells are located and the horizontal lines in the corresponding two-dimensional cell map are assimilated into a type of bus segment, and the same type of bus segments are merged into a new bus segment, so as to obtain a two-dimensional cell map of the branch after dimensionality reduction including the new bus layout;

[0023] According to the two-dimensional cell map of the branch after dimensionality reduction, the cells in the two-dimensional cell map of the interval of the bus connection are synchronously reduced in dimensionality. During the processing, if a bus connection is connected to the same type of bus line segment, the bus connection is invalid, and a new two-dimensional cell map of the bus connection is obtained;

[0024] In the new two-dimensional cell map of bus couplings, if there are two or more marked cells for the same bus coupling, the bus section where the corresponding bus coupling is located will be designated as an isolation partition within the same station, otherwise it will be an independent isolation partition within the station.

[0025] Preferably, the identifying of CT disconnection according to the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition includes:

[0026] If in a certain station isolation zone, the bus differential protection current of the station isolation zone and the differential current of each bus section in the zone where the interval is located are greater than the CT disconnection setting value, it is identified that the corresponding branch interval has a CT disconnection;

[0027] If in an isolated zone within a station, there is no phase current in the bus-tie interval but there is zero-sequence current, the bus differential protection current in the isolated zone within the station is balanced, the differential currents of the bus sections in the zone where the bus-tie is located are unbalanced, but the sum of the differential currents of the bus sections in the zone is balanced, then it is identified that the CT line is broken in the corresponding bus-tie interval.

[0028] Preferably, the method of identifying the CT disconnection situation according to the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition further includes:

[0029] When a CT disconnection occurs in an interval, the number of bus sections affected by the CT disconnection is alarmed based on the number N of bus sections described in the multi-dimensional interval data model of the interval.

[0030] A second aspect of the present invention provides a relay protection device for automatically identifying CT disconnection in multiple buses, comprising:

[0031] A data acquisition module, used to acquire data in a multi-dimensional interval data model for each interval in the station;

[0032] The multi-bus CT line break identification and diagnosis module is used to create a two-dimensional cell map of buses and intervals based on the data of the multi-dimensional interval data model, and to normalize the bus segments of the horizontal cells in the two-dimensional cell map, identify the isolated partitions within the station, calculate the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, so as to identify the CT line break situation.

[0033] A third aspect of the present invention provides a terminal, comprising a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the method.

[0034] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method when executed by a processor.

[0035] Compared with the prior art, the beneficial effects of the present invention include at least:

[0036] The present invention uses the information in the multidimensional interval data model defined in intervals, such as the switch status information and interval current data collected by itself, to create a two-dimensional cell map based on bus and interval information. After the cells are normalized to the bus segments, the independently segmented bus areas are identified, and the bus differential protection current of the isolated partition in the station and the differential current of each bus segment in the partition are calculated. The interval where the CT line is broken can be accurately identified in the multi-bus configuration, and it can be applied to various states of bus protection operation. This method can not only effectively identify the various types of CT line breaks faced by the relay protection device, but also accurately locate the specific location of the CT line break, providing key reference information for subsequent device maintenance and overhaul work.

[0037] The present invention identifies the connection status of the interval and different bus sections according to the switch status of the interval and multiple bus sections, and fills the cells in the bus-interval two-dimensional cell map according to the connection status, which can break the fixed optional relationship between the bus and the interval, and can determine that the same branch is connected to more than two bus sections at the same time. It is not subject to the restriction of the mainstream bus protection bus being either one or the other, and can be connected to any bus section in the station, which solves the problem that the branch connected to the existing mainstream bus protection can only choose one of the two optional bus sections at most, and the same branch can only be connected to two bus sections at most.

[0038] Based on the interval properties, the present invention normalizes the bus segment processing for the cells in the bus-interval two-dimensional cell map, and identifies the isolated partitions within the station, which can support the identification of three or more bus segments. In the case of three or more bus segments, a clear dividing line can be provided for the correct calculation of the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, solving the problem that the existing mainstream bus protection only supports two or three bus segments.

[0039] The present invention can also adaptively identify the busbars where each branch is located according to the state of the interval-mounted busbars, such as the state of the isolating knife switch, and can adaptively adjust the isolation partition when the state of the isolating knife switch on the branch changes.

[0040] The method for automatically identifying CT disconnection in multiple buses of the present invention is not only applicable to traditional main connections such as double bus, double bus single section, single bus, one and a half connections, but can also be widely adapted to various special main connections in the petrochemical industry, such as six-zone bus, four-zone bus and other special main connections that traditional bus protection cannot adapt to, and the software does not need to change according to the main connection method.

[0041] The present invention is not limited to a specific existing primary design, can flexibly adapt to the primary wiring, simplifies the software engineering version configuration, and improves the adaptability of busbar protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flowchart of a method for automatically identifying CT disconnection in multiple buses according to the present invention;

[0043] Figure 2 It is a structural diagram of a multi-dimensional interval data model in an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of a two-dimensional cell map showing the relationship between intervals and busbars in an embodiment of the present invention;

[0045] Figure 4 A two-dimensional cell map obtained by marking cells according to the branch connection busbar situation in an embodiment of the present invention;

[0046] Figure 5 A two-dimensional cell map of the same branch connected to different buses in an embodiment of the present invention;

[0047] Figure 6 A two-dimensional cell map for maximizing cell merging in an embodiment of the present invention;

[0048] Figure 7 is a busbar segment that can be normalized in the embodiment of the present invention;

[0049] Figure 8 A two-dimensional cell map of updating branch connection conditions for a normalized bus segment in an embodiment of the present invention;

[0050] Fig. 9 It is a simplified two-dimensional cell map in an embodiment of the present invention;

[0051] Fig.10 A two-dimensional cell map obtained by marking cells according to the actual busbar connection situation of the bus coupling in the embodiment of the present invention;

[0052] Fig.11 Two electrically isolated busbar areas in an embodiment of the present invention;

[0053] Fig.12 This is a CT disconnection judgment logic diagram in an embodiment of the present invention;

[0054] Fig.13 The present invention is a flowchart of a method for automatically identifying CT disconnection in multiple buses. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0056] Embodiment 1 of the present invention provides a method for automatically identifying CT disconnection in multiple buses, and identifies CT disconnection anomalies in multiple buses, such as Figure 1 , Fig.13 As shown, the method includes:

[0057] Step 1: Obtain data in the multidimensional interval data model for each interval in the station;

[0058] Further preferably, the present invention defines a multi-dimensional interval data model to store data collected in real time and to calculate and analyze data;

[0059] The multi-dimensional interval data model uses intervals as units, defines interval-specific information, and records relevant data for each interval. The following description is based on a single interval, and it is no longer emphasized that all intervals require the same processing.

[0060] like Figure 2 As shown, multidimensional interval data models include six categories:

[0061] The first category: bay description, including bay serial number, bay name, bay nature, and number of busbar sections;

[0062] In specific implementation, the first type of data of each interval multidimensional interval data model is preset:

[0063] Interval serial number, the serial number can be customized, the value can be different, there is no requirement for the starting serial number, there is no requirement for the serial number to be continuous, it is only used to distinguish the different intervals;

[0064] Interval name, same as the scheduling interval description or a custom description;

[0065] The nature of the interval, depending on whether the current is connected, the branch or bus is defined as two types: the branch with current connected, the bus;

[0066] The number of bus sections, the number of bus sections actually put into use in the main wiring of the current station.

[0067] The second category: switch status, which includes 1G status, 2G status, ... nG status;

[0068] In specific implementation, by collecting the switch status information, the connection status of each bay and the multiple busbars is monitored in real time; by collecting the switch status information, the connection status of each bay and the multiple busbars is changed instantly, and the second type of data of the multi-dimensional bay data model of each bay is updated;

[0069] Specifically, the status of the switch connecting the interval and the multi-section bus is collected in real time and stored in the second type of data of the multidimensional interval data model where the interval is located, namely the interval status information, that is, 1G status, 2G status, ... nG status, recording the closed status or the open status.

[0070] If the status of the switch connecting the real-time acquisition interval and the multi-section bus changes, the second type of interval status information stored in the multidimensional interval data model where the interval is located, i.e., 1G status, 2G status, ... nG status, is updated to update the closed status or open status.

[0071] According to the status of the switches in all intervals of the main wiring in the station, there are two situations:

[0072] 1) There is no busbar connected to the bay, that is, no busbar is connected, indicating that the bay is not put into operation in the substation.

[0073] 2) The busbar is connected at intervals, that is, it is connected to the running busbar, indicating that the number of connected busbar sections is greater than or equal to 1.

[0074] The third category: interval current, which includes phase A current, phase B current, phase C current, and zero-sequence current;

[0075] During specific implementation, the health status of the secondary circuit of each interval is monitored in real time by collecting interval current data.

[0076] Specifically, the three-phase current of the secondary circuit where the interval is located is collected through the AD acquisition circuit of the device, and stored in the third type of data of the multi-dimensional interval data model where the interval is located: interval current information, namely, phase A current, phase B current, and phase C current, and the current value of each phase is recorded.

[0077] Based on the actual data, the current situation of each interval is comprehensively analyzed, the zero-sequence current value of each interval is calculated in real time, and the third-category interval current stored in the multi-dimensional interval data model of each interval is synchronously updated.

[0078] The fourth category: busbar areas with electrical isolation within the station (isolation zones within the station), which are the zone number and the busbar section number within the zone. The busbar section number within the zone can be multi-valued.

[0079] The electrically isolated busbar area in the station is an independently divided busbar area, specifically referring to an area composed of multiple busbar sections of the same voltage level with electrical connection based on Kirchhoff's law. Each partition is independent of each other and has no electrical connection. For the main connection of a certain voltage level of a single substation, it can be divided into multiple electrically isolated independent busbar areas according to the electrical disconnection point.

[0080] Generally, the number of busbar sections in the main connection of a certain voltage level of a single substation will not exceed three. The number of busbar sections described in the present invention may include more than three busbar sections, and the independently divided busbar area may contain any busbar section, and the independently divided busbar area may be greater than one.

[0081] Category 5: In-station isolated partition bus differential protection current, including A-phase in-station isolated partition bus differential protection current, B-phase in-station isolated partition bus differential protection current, and C-phase in-station isolated partition bus differential protection current;

[0082] Category 6: Differential currents of each bus section within the partition, including the differential currents of each bus section within the A-phase partition, the differential currents of each bus section within the B-phase partition, and the differential currents of each bus section within the C-phase partition.

[0083] Step 2: Create a bus-interval two-dimensional cell map based on the data of the multi-dimensional interval data model, and normalize the cells in the two-dimensional cell map to the bus segment, identify the isolated partitions within the station, calculate the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, so as to identify the CT disconnection situation.

[0084] Preferably, the current situation of each interval is comprehensively analyzed based on the measured interval current data. A two-dimensional cell map based on bus and interval information is created, and the horizontal cells are normalized to the bus segment. The bus differential protection current of the isolated partition in the station and the differential current of each bus segment in the partition are calculated to comprehensively judge the branch CT disconnection and the bus tie CT disconnection. Specifically including:

[0085] Step 2.1: According to the number of bus sections N and the number of bays of the main connection in the station M, create a bus-bay two-dimensional cell map for bays of different properties, where the horizontal direction is the bus and the vertical direction is the bay;

[0086] Further preferably, a two-dimensional cell map of N bus segments and M intervals is created according to the number of bus segments N and the number of intervals within the station of the first type of data in the multidimensional interval data model.

[0087] Taking the main connection of the station with 7 busbars and 18 bays as an example, a two-dimensional cell map based on the 7 busbars and 18 bays is created, where the 18 bays are 9 common branches with current and 9 busbars.

[0088] The two-dimensional cell map of busbar-branch and busbar-bus coupling are as follows: Figure 3 As shown in (a) and (b) in .

[0089] Step 2.2: According to the switch status of the bay and the multi-section busbar, identify the connection status of the bay and the different busbar sections, and fill the cells in the two-dimensional cell map according to the connection status. If connected, mark the corresponding cell, such as coloring the corresponding cell or adding a symbol, etc. If not connected, do not mark the corresponding cell;

[0090] Further preferably, the interval property p of the first type of data, the switch status s_1G, s_Ng and other information of the second type of data traverse the two-dimensional cell map and fill the cells in the map. If there is a connection, the cell is colored or marked with symbols, etc. If there is no connection, the cell is not marked.

[0091] This embodiment is explained in a way of adding annotations. Cells are annotated according to the connection of branches to the busbar. The corresponding cells with connection are annotated with "O". The obtained two-dimensional cell map is as follows: Figure 4 shown.

[0092] Further, such as Figure 5 As shown, check by branch. If the same branch is connected to different buses, add a mark "△" to the corresponding cell.

[0093] Furthermore, the cell merging is maximized. Find out whether there are different branches connected to the same bus segment. If so, merge all other bus segments connected to the branch into the same bus segment, and the relevant branch connects to all such bus segments. When branch 5 is connected to buses 2, 4, and 6 at the same time, and branch 9 is connected to buses 1 and 4 at the same time, then branch 5 and branch 9 are connected to bus 4 together, then it is considered that branch 5 and branch 9 are connected to the same bus segment at the same time, that is, bus 1, 2, 4, and 6. Figure 6 shown.

[0094] Step 2.3: Based on the interval properties, the cells in the two-dimensional cell map are processed into normalized bus segments, and the isolated partitions within the station are identified;

[0095] Further preferably, first, for the branch with flow in the interval property, the busbar segments where the marked cells passed by the horizontal line are located are normalized and simplified into a new two-dimensional cell map, that is, they are assimilated into a type of busbar segment vertically, and the same type of busbar segments are merged into a new busbar segment to obtain a new busbar layout and a two-dimensional cell map of the branch after dimensionality reduction processing;

[0096] Then, according to the two-dimensional cell map of the branch after dimensionality reduction, the cells in the two-dimensional cell map of the interval of the bus connection are synchronously reduced in dimension, that is, the new bus layout is synchronized. If a bus connection is connected to the same type of bus section, the bus connection is invalid, and a new bus connection two-dimensional cell map is obtained;

[0097] Finally, in the new bus coupler two-dimensional cell map, if the same bus coupler has two or more labeled cells, the bus segments are classified as the same electrical area, otherwise they are independent electrical areas.

[0098] The two-dimensional cell map clearly shows the connection status of each bay on each busbar, and can clearly divide the electrically isolated busbar area through visualization.

[0099] like Figure 7 As shown, looking at the bus segments that can be normalized, bus 2 / 4 / 6 can be normalized to bus 1.

[0100] Further, such as Figure 8 As shown, the normalized bus section updates the branch connection status. For example, if the original branch 1 is connected to bus 2, it is adjusted to branch 1 connected to bus 1 / 2 / 4 / 6, and the corresponding cell is marked with "O"; if the original branch 2 is connected to bus 6, it is adjusted to branch 7 connected to bus 1 / 2 / 4 / 6, and the corresponding cell is marked with "O".

[0101] Further, such as Fig. 9 As shown, the dimensionality of the two-dimensional cell map is reduced and similar busbar segments are merged.

[0102] Furthermore, according to the actual bus connection situation of the bus tie, the cells are marked, and the obtained two-dimensional cell map is as follows Fig.10 shown.

[0103] Combined with the simplified two-dimensional cell map of the branch, check the busbar segments that the busbar can connect to and determine the busbar areas that can be electrically isolated.

[0104] 1) For example, the original bus tie 1 is connected to bus 2 and bus 3. Since bus 1246 is unified, it is adjusted to bus tie 1 connected to bus 1 / 2 / 4 / 6 and bus 3, and the corresponding two cells are marked with "O";

[0105] 2) The same is true for bus tie 5, which is adjusted to connect bus 1246 and bus 5, and the corresponding two cells are marked with "O";

[0106] 3) The original bus tie 9 is connected to busbars 1 and 4. Because busbars 1 and 4 are unified into the same busbar segment, bus tie 9 is invalid and the corresponding cell is marked with “×”.

[0107] Finally, if Fig.11As shown, the main wiring diagram of the complex multi-bay and multi-busbar station is simplified into two electrically isolated busbar areas.

[0108] Independent area 1: busbar 1246 and busbar 3 are connected through bus tie 1, and busbar 1246 and busbar 5 are connected through bus tie 5. It is a single bus three-section wiring. There are branches 1, 5, 6, 7, and 9 on busbar 1246, branch 8 on busbar 3, and branch 3 on busbar 5.

[0109] Independent area 2: Busbar 7, only branch 2.

[0110] Step 2.4: Calculate the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition respectively;

[0111] Further preferably, based on the independently divided bus areas in the station identified by the new two-dimensional cell map, the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition are calculated respectively, and the calculation method is the same as the large difference and small difference method of conventional bus protection calculation.

[0112] Step 2.5: Identify CT disconnection based on the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition.

[0113] Further preferably, the CT disconnection judgment logic is:

[0114] like Fig.12 As shown in (a), under the current main connection condition in the station, in a certain independently divided bus area, the differential protection current of the bus in the isolated partition of the station and the differential current of each bus section in the partition where the interval is located are greater than the CT line break setting value, then the device identifies the branch CT line break alarm or lockout.

[0115] like Fig.12 As shown in (b), under the current main connection condition, in a certain independently divided bus area, there is no phase current in the bus interval but there is zero-sequence current, the bus differential protection current of the isolated partition in the station is balanced, the differential currents of each bus section in the partition where the bus is located are unbalanced, but the sum of the differential currents of each bus section in the partition is balanced, then the device identifies the bus CT disconnection alarm or lockout.

[0116] The CT disconnection alarm will clearly indicate the number of bus sections affected. Therefore, when a CT disconnection occurs in a certain interval, the number of bus sections affected needs to be reminded.

[0117] According to the first type of information in the dedicated single-interval multi-dimensional interval data model, the number of all bus sections where the interval is located is determined, and the fourth type of information is supplemented. According to the fourth type of information, the number of bus sections affected by the alarm CT disconnection is determined.

[0118] The above method does not conflict with the standard CT disconnection logic.

[0119] Embodiment 2 of the present invention provides a relay protection device for automatically identifying CT disconnection in multiple buses, comprising:

[0120] A data acquisition module, used to acquire data in a multi-dimensional interval data model for each interval in the station;

[0121] The multi-bus CT line break identification and diagnosis module is used to create a two-dimensional cell map of buses and intervals based on the data of the multi-dimensional interval data model, and to normalize the bus segments of the horizontal cells in the two-dimensional cell map, identify the isolated partitions within the station, calculate the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, so as to identify the CT line break situation.

[0122] Embodiment 3 of the present invention provides a terminal, including a processor and a storage medium; the storage medium is used to store instructions; the processor is used to operate according to the instructions to execute the steps of the method.

[0123] Embodiment 4 of the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method when executed by a processor.

[0124] Compared with the prior art, the beneficial effects of the present invention include at least:

[0125] The present invention uses the information in the multidimensional interval data model defined in intervals, such as the switch status information and interval current data collected by itself, to create a two-dimensional cell map based on bus and interval information. After the cells are normalized to the bus segments, the independently segmented bus areas are identified, and the bus differential protection current of the isolated partition in the station and the differential current of each bus segment in the partition are calculated. The interval where the CT line is broken can be accurately identified in the multi-bus configuration, and it can be applied to various states of bus protection operation. This method can not only effectively identify the various types of CT line breaks faced by the relay protection device, but also accurately locate the specific location of the CT line break, providing key reference information for subsequent device maintenance and overhaul work.

[0126] The present invention identifies the connection between the interval and different bus sections according to the switch status of the interval and the multi-section bus, and fills the cells in the bus-interval two-dimensional cell map according to the connection status, which can break the fixed optional relationship between the bus and the interval, and can determine that the same branch is connected to more than two bus sections at the same time, and is not subject to the restriction of the mainstream bus protection bus to choose one of the two bus sections, and can be connected to any bus section in the station. It solves the problem that the branch connected to the existing mainstream bus protection can only choose one of the two optional bus sections, and the same branch can only be connected to two bus sections at most.

[0127] Based on the interval properties, the present invention normalizes the bus segment processing for the cells in the bus-interval two-dimensional cell map, and identifies the isolated partitions within the station, which can support the identification of three or more bus segments. In the case of three or more bus segments, a clear dividing line can be provided for the correct calculation of the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, solving the problem that the existing mainstream bus protection only supports two or three bus segments.

[0128] The present invention can also adaptively identify the busbars where each branch is located according to the state of the interval-mounted busbars, such as the state of the isolating knife switch, and can adaptively adjust the isolation partition when the state of the isolating knife switch on the branch changes.

[0129] The method for automatically identifying CT disconnection in multiple buses of the present invention is not only applicable to traditional main connections such as double bus, double bus single section, single bus, one and a half connections, but can also be widely adapted to various special main connections in the petrochemical industry, such as six-zone bus, four-zone bus and other special main connections that traditional bus protection cannot adapt to, and the software does not need to change according to the main connection method.

[0130] The present invention is not limited to a specific existing primary design, can flexibly adapt to the primary wiring, simplifies the software engineering version configuration, and improves the adaptability of busbar protection.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for automatically identifying CT disconnection in multiple buses, characterized in that: The method comprises: Obtaining data in a multi-dimensional interval data model for each interval within the station; A busbar-interval two-dimensional cell map is created based on the data of the multidimensional interval data model, and the cells in the two-dimensional cell map are normalized into bus sections to identify the isolated partitions within the station. The busbar differential protection current of the isolated partition within the station and the differential current of each bus section in the partition are calculated to identify CT line breaks.

2. The method for automatically identifying CT disconnection in multiple busbars according to claim 1 is characterized in that: The data in the multi-dimensional interval data model includes interval description, switch status, and interval current; The interval description is preset, including the interval serial number, interval name, interval nature, and the number of bus sections N; The switch state is the switch state of the interval connected to the multi-section busbar, which is divided into a closed state and an open state; The interval current includes the A-phase current, B-phase current, C-phase current and zero-sequence current of the secondary circuit where the interval is located.

3. The method for automatically identifying CT disconnection in multiple busbars according to claim 2 is characterized in that: The interval serial number is a customized different value; the interval name uses the same scheduling interval description or a customized description; the interval nature is divided into branches with current access and busbars; the number of busbar sections is the number of busbar sections actually put into use in the current main connection in the station.

4. The method for automatically identifying CT disconnection in multiple busbars according to claim 2 is characterized in that: The method of creating a bus-interval two-dimensional cell map based on the data of the multi-dimensional interval data model, normalizing the cells in the two-dimensional cell map to a bus segment, identifying the isolation partition within the station, calculating the bus differential protection current of the isolation partition within the station and the differential current of each bus segment in the partition, thereby identifying the CT disconnection situation, specifically includes: According to the number of busbar sections N and the number of bays of the main wiring in the station M, a busbar-bay two-dimensional cell map is created for bays of different properties, where the horizontal direction is the busbar and the vertical direction is the bay; According to the switch status of the bay and the multi-section busbar, the connection status of the bay and different busbar sections is identified, and the cells in the two-dimensional cell map are filled according to the connection status. If connected, the corresponding cell is marked, and if not connected, the corresponding cell is not marked; Based on the interval properties, the cells in the two-dimensional cell map are processed into normalized bus segments, and the isolated partitions within the station are identified; Calculate the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition respectively; The CT disconnection situation is identified based on the bus differential protection current of the isolated partition within the station and the differential current of each bus section within the partition.

5. The method for automatically identifying CT disconnection in multiple busbars according to claim 4 is characterized in that: After filling the cells in the two-dimensional cell map according to the connection situation, find out whether there is a situation where different branch intervals are connected to the same bus segment. If so, all other bus segments connected to the branch are merged into the same type of bus segments, and the relevant branch intervals are connected to all such bus segments to maximize cell merging.

6. The method for automatically identifying CT disconnection in multiple busbars according to claim 4 is characterized in that: Based on the interval property, the cells in the two-dimensional cell map are processed into a normalized bus segment, and the isolated partitions within the station are identified, specifically: For the interval of the branch with current access, the bus segments where the marked cells are located and the horizontal lines in the corresponding two-dimensional cell map are assimilated into a type of bus segment, and the same type of bus segments are merged into a new bus segment, so as to obtain a two-dimensional cell map of the branch after dimensionality reduction including the new bus layout; According to the two-dimensional cell map of the branch after dimensionality reduction, the cells in the two-dimensional cell map of the interval of the bus connection are synchronously reduced in dimensionality. During the processing, if a bus connection is connected to the same type of bus line segment, the bus connection is invalid, and a new two-dimensional cell map of the bus connection is obtained; In the new two-dimensional cell map of bus couplings, if there are two or more marked cells for the same bus coupling, the bus section where the corresponding bus coupling is located will be designated as an isolation partition within the same station, otherwise it will be an independent isolation partition within the station.

7. The method for automatically identifying CT disconnection in multiple busbars according to claim 4 is characterized in that: The method of identifying the CT disconnection situation according to the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition includes: If in a certain station isolation zone, the bus differential protection current of the station isolation zone and the differential current of each bus section in the zone where the interval is located are greater than the CT line break setting value, it is identified that the corresponding branch interval has a CT line break; If in an isolated zone within a station, there is no phase current in the bus-tie interval but there is zero-sequence current, the bus differential protection current in the isolated zone within the station is balanced, the differential currents of the bus sections in the zone where the bus-tie is located are unbalanced, but the sum of the differential currents of the bus sections in the zone is balanced, then it is identified that the CT line is broken in the corresponding bus-tie interval.

8. The method for automatically identifying CT disconnection in multiple busbars according to claim 7 is characterized in that: The method of identifying the CT disconnection situation according to the bus differential protection current of the isolated partition in the station and the differential current of each bus section in the partition also includes: When a CT disconnection occurs in an interval, the number of bus sections affected by the CT disconnection is alarmed based on the number N of bus sections described in the multi-dimensional interval data model of the interval.

9. A relay protection device for automatically identifying CT disconnection in multiple buses, using the method described in any one of claims 1 to 8, characterized in that: The device comprises: A data acquisition module, used to acquire data in a multi-dimensional interval data model for each interval in the station; The multi-bus CT line break identification and diagnosis module is used to create a two-dimensional cell map of buses and intervals based on the data of the multi-dimensional interval data model, and to normalize the bus segments of the horizontal cells in the two-dimensional cell map, identify the isolated partitions within the station, calculate the bus differential protection current of the isolated partition within the station and the differential current of each bus segment in the partition, so as to identify the CT line break situation.

10. A terminal comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1-8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the 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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