An independent local area network stability control automatic load slice area identification method and system

Abstract

The application discloses an independent local area power grid stability control automatic load subarea identification method and system, and the independent local area power grid stability control automatic load subarea identification method comprises the following steps: a subarea transformer substation stability control host computer establishes an element relation database according to an electrical main wiring diagram, element types, element numbers and the connection relationship among the elements; a subarea transformer substation stability control slave computer collects electrical quantity information of inter-station tie lines, in-station main transformers and in-station loads, and collects position information of all circuit breakers and disconnectors in the station; a side station stability control collects position information of tie line switches on the opposite side; and the subarea transformer substation stability control host computer judges the on-off states of the inter-station tie lines, the in-station main transformers and the in-station loads according to the above collected information, and performs topological identification on the transformer substation elements. The application solves the problem that the load subarea selection and switching of an open-loop point transformer substation of an independent local area power grid are difficult due to load reversal, and is easy to maintain.

Description

Technical Field

[0001] This invention relates to the field of power system safety and stability control technology, specifically to an automatic load segmentation identification method and system for independent local power grid stability control. Background Technology

[0002] Local power grids are typically weakly connected to the main power grid, with a flimsy grid structure and low voltage levels. During operation, they often fail to meet the "N-1" rule and rely heavily on stability control systems. Due to continuous load growth, local power grids may employ multiple connections to the main grid and operate in sections after the electromagnetic or power loops are broken. The disconnection point in a local power grid may be located on one side of the interconnection line between power plants or at the bus tie within a substation. When the disconnection point is chosen at the substation bus tie, all loads within the substation may be connected to different sections. Local power grid dispatchers will perform load switching operations on the substation based on the power output, load power, and power flow at the grid connection point. This results in the same load within the substation potentially being connected to different sections at different times.

[0003] When a load shedding system in a certain area requires the removal of loads within a substation, the system cannot automatically identify the area where the load is located, leading to difficulties in load selection and shedding. The existing solution is to treat the substation as two separate sites, installing two sets of load shedding systems connected to the superior control systems of different areas. Both sets of control systems re-collect load data, and the load shedding zone is determined by activating or deactivating the load shedding switches on both systems during load shedding, resulting in a large maintenance workload. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems mentioned above and / or existing independent local power grids, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to provide an automatic load segmentation identification method and system for independent local power grid stability control, which makes load segmentation selection convenient and easy to maintain.

[0007] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0008] An automatic load segmentation identification method for independent local power grid stability control includes the following steps:

[0009] S1. The regional substation stability control host establishes a component relationship database based on the main electrical wiring diagram, component type, component number, and connection relationship between components.

[0010] S2, the substation stability control slave device collects electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, and collects the position information of all circuit breakers and disconnect switches in this station. The stability control of the opposite station collects the position information of the switches on the opposite side of the inter-station tie lines.

[0011] S3. The substation stability control host determines the on / off status of inter-station tie lines, main transformers and loads within the station based on the above collected information, and performs topology identification on substation components.

[0012] S4. Based on the topology analysis results, the substation stability control host determines the load zoning situation of all loads in the substation. Combining the load size, allowable load shedding situation and load priority settings of different zones in the substation, the host calculates the load shedding capacity of different load priorities in the two zones respectively.

[0013] S5. The substation stability control host will send the load amounts that can be cut off due to different load priorities calculated for the two areas to the next level stability control master station or substation respectively. The stability control of the opposite site and the next level stability control master station or substation can be the same stability control site or different stability control sites.

[0014] S6. The substation stability control host selects and switches the load in the corresponding area according to the command of the upper-level stability control master station or substation, the inter-station tie line, or the overload situation of the main transformer.

[0015] As a preferred embodiment of the automatic load segmentation identification method for independent local power grid stability control described in this invention, the load priority is represented by numbers, where 0 indicates no switching, 1 indicates priority switching, 2 indicates second priority switching, and 3 indicates last switching.

[0016] As a preferred embodiment of the independent local power grid stability control automatic load segmentation identification method described in this invention, the component types include: inter-station tie lines, main transformers, loads, busbars, circuit breakers, and disconnect switches.

[0017] As a preferred embodiment of the independent local power grid stability control automatic load segmentation identification method described in this invention, in step S3, when judging the operation and shutdown status of inter-station tie lines and main transformers within the station, an operation and shutdown criterion combining electrical quantities and circuit breaker location information is adopted, or a pure electrical quantity operation and shutdown criterion can be adopted according to actual conditions.

[0018] As a preferred embodiment of the independent local power grid stability control automatic load segmentation identification method described in this invention, in step S3, when performing topology identification on the substation, the bus section of the inter-station tie line is determined based on the on / off status of the inter-station tie line and the location information of the disconnecting switch in the corresponding bay; the area where the high-voltage side busbar of the substation is located is determined based on the location information of the high-voltage side bus tie bay circuit breaker and disconnecting switch; the area where the main transformer is located is determined based on the on / off status of the main transformer and the location information of the high-voltage side disconnecting switch of the main transformer; and the area where the medium- and low-voltage side busbar is located is determined based on the location information of the medium- and low-voltage side circuit breakers and disconnecting switches of the main transformer, combined with the location information of the medium- and low-voltage side bus tie bay circuit breakers and disconnecting switches.

[0019] As a preferred embodiment of the independent local power grid stability control automatic load segmentation identification method described in this invention, according to the load importance and the total shelvable load capacity of different segments, for cases where the load can be shelved both remotely and locally, only one set of load shelving priorities can be set.

[0020] For situations where loads cannot be switched remotely but can be switched locally, load priorities can be set to remote load switching priority and local load switching priority.

[0021] An independent local power grid stability control automatic load segmentation identification system includes:

[0022] The component library creation module is configured to create a component relationship library for the substation based on the substation's main wiring diagram, component information, and the connection relationships between components.

[0023] The information acquisition module is configured to collect electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, as well as the position information of all circuit breakers and disconnect switches in the station and the position information of switches on the opposite side.

[0024] Topology analysis module: It is configured to determine the on / off status of inter-station tie lines, main transformers and loads within the station based on the collected electrical quantity information and switch position information, and to perform topology identification of substation components;

[0025] The load segmentation identification module is configured to determine the status of all load segments in the substation based on the topology analysis results, and calculate the load shedding capacity of different load priorities in two segments by combining the load size, allowable load shedding status and load priority settings of different segments in the substation.

[0026] Load selection module: It is configured to select the load in the corresponding area to be cut off based on the command of the upper-level stability control master station or substation, or the overload situation of the inter-station tie line or the main transformer.

[0027] Load shedding execution module: configured to shed the load in the corresponding area according to the selection command.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention solves the problem of difficulty in load segmentation selection and switching in open-loop substations of independent local power grids due to load switching by using an automatic load segmentation identification method and system for independent local power grid stability control. It is also easy to maintain and has certain practical value for load participation in stability control selection and switching in open-loop substations of independent local power grids. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0030] Figure 1 This is a flowchart of an automatic load segmentation identification method for independent local power grid stability control according to the present invention;

[0031] Figure 2 This is a schematic diagram of the principle of an independent local power grid stability control automatic load segmentation identification system according to the present invention. Detailed Implementation

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0035] This invention provides an automatic load segmentation identification method and system for independent local power grid stability control, which solves the problem of difficulty in selecting and switching load segments in open-loop substations of independent local power grids due to load switching, and is easy to maintain.

[0036] Figure 1 The diagram shown is a flowchart of an automatic load segmentation identification method for independent local power grid stability control according to the present invention. Please refer to [link / reference]. Figure 1 The specific steps of the independent local power grid stability control automatic load segmentation identification method of this embodiment are as follows:

[0037] An automatic load segmentation identification method for independent local power grid stability control includes the following steps:

[0038] S1. The substation stability control host establishes a component relationship library based on the main electrical wiring diagram, component type, component number, and connection relationship between components. In this embodiment, the component types include: inter-station tie line, main transformer, load, busbar, circuit breaker, and disconnector.

[0039] S2, the substation stability control slave device collects electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, and collects the position information of all circuit breakers and disconnect switches in this station. The stability control of the opposite station collects the position information of the switches on the opposite side of the inter-station tie lines.

[0040] S3. The substation stability control host determines the on / off status of inter-station tie lines, main transformers within the substation, and loads within the substation based on the collected information, and performs topology identification of substation components. Specifically, when determining the on / off status of inter-station tie lines and main transformers within the substation, an on / off criterion combining electrical quantities and circuit breaker location information is used. Alternatively, a pure electrical quantity on / off criterion can be used depending on the actual situation. When performing substation topology identification, the operating bus section of the inter-station tie line is determined based on its on / off status and the location information of the disconnecting switch in the corresponding bay; the area where the high-voltage side busbar is located is determined based on the location information of the high-voltage side bus tie bay circuit breaker and disconnecting switch; the area where the main transformer is located is determined based on its on / off status and the location information of the high-voltage side disconnecting switch of the main transformer; and the area where the medium- and low-voltage side busbar is located is determined based on the location information of the medium- and low-voltage side circuit breakers and disconnecting switches of the main transformer, combined with the location information of the medium- and low-voltage side bus tie bay circuit breaker and disconnecting switch.

[0041] S4. The substation stability control host determines the load zoning situation of all loads in the substation based on the topology analysis results. Combining the load size, allowable load shedding status, and load priority settings of different zones in the substation, it calculates the load shedding capacity of different load priorities for the two zones. In this embodiment, the load priority is represented by numbers, where 0 indicates prohibited shedding, 1 indicates priority shedding, 2 indicates secondary priority shedding, and 3 indicates last priority shedding. Based on the importance of the load and the total shedding capacity of different zones, if the load can be shedding both remotely and locally, only one set of load shedding priorities can be set. If the load cannot be shedding remotely but can be shedding locally, the load priorities can be set as remote load shedding priority and local load shedding priority.

[0042] S5. The substation stability control host will send the different load priority shunting loads calculated for the two areas to the next level stability control master station or substation respectively. The stability control of the opposite site and the next level stability control master station or substation can be the same stability control site or different stability control sites.

[0043] S6. The substation stability control host selects and switches the load in the corresponding area according to the command of the upper-level stability control master station or substation, the inter-station tie line, or the overload situation of the main transformer.

[0044] On the other hand, the present invention also provides an automatic load segmentation identification system for independent local power grid stability control to realize the above-mentioned automatic load segmentation identification method for independent local power grid stability control. The system includes a component library establishment module, an information acquisition module, a topology analysis module, a load segmentation identification module, a load selection module, and a load shedding execution module.

[0045] The component library creation module is configured to create a component relationship library for the substation based on the substation's main wiring diagram, component information, and the connection relationships between components.

[0046] The information acquisition module is configured to collect electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, as well as the position information of all circuit breakers and disconnect switches in the station and the position information of switches on the opposite side.

[0047] The topology analysis module is configured to determine the on / off status of inter-station tie lines, main transformers within the station, and loads within the station based on the collected electrical quantity information and switch position information, and to perform topology identification on substation components;

[0048] The load segmentation identification module is configured to determine the status of all load segments in the substation based on the topology analysis results, and calculate the load that can be cut off for different load priorities in two segments by combining the load size, allowable load shedding status and load priority settings of different segments in the substation.

[0049] The load selection module is configured to select the loads in the corresponding area to be cut off based on the commands from the previous level stability control master station or substation, or the overload status of the inter-station tie line or main transformer.

[0050] The load shedding execution module is configured to shed the load in the corresponding area according to the shedding command.

[0051] by Figure 2 For example, the disconnection point of the 110kV zoned substation is selected at the 110kV bus tie. The loads of this substation are located in two different zones: loads 1-3 and 10-13 are located in zone 1, while loads 4-9 and 14-15 are located in zone 2. The main unit of the substation's stability control execution station includes a component library establishment module, a topology analysis module, a load zone identification module, and a load selection module. The slave unit of the substation's stability control execution station includes an information acquisition module and a load shedding execution module. The substation's stability control execution station communicates with the upper-level stability control master station or execution station of each of the two zones, and selects and cuts off the loads in the corresponding zones based on commands from the upper-level stability control master station or slave station, the inter-station tie line of this substation, or the overload status of the main transformer.

[0052] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for automatic load segmentation identification in independent local power grid stability control, characterized in that, Includes the following steps: S1. The regional substation stability control host establishes a component relationship database based on the main electrical wiring diagram, component type, component number, and connection relationship between components. S2. The substation stability control slave unit collects electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, and collects the position information of all circuit breakers and disconnect switches in the station. The stability control of the opposite station collects the position information of the opposite switch of the inter-station tie line and sends it to the substation stability control host. S3. The substation stability control host in the substation area determines the operation and shutdown status of the inter-station tie line and the main transformer in the substation based on the above collected information, and performs topology identification of the substation. S4. Based on the topology analysis results, the substation stability control host determines the load zoning situation of all loads in the substation. Combining the load size, allowable load shedding situation and load priority settings, it calculates the load shedding amount for different load priorities in the two zones respectively. S5. The substation stability control host will send the load shedding amounts calculated for different load priorities in the two areas to the next-level stability control master station or substation respectively; the stability control of the opposite site and the next-level stability control master station or substation can be the same stability control site or different stability control sites. S6. The substation stability control host selects and switches the load in the corresponding area according to the command of the upper-level stability control master station / substation or the overload status of the inter-station tie line / main transformer.

2. The method for automatic load segmentation identification in independent local power grid stability control according to claim 1, characterized in that, The load priority is represented by numbers, where 0 indicates no switching, 1 indicates priority switching, 2 indicates second priority switching, and 3 indicates last switching.

3. The method for automatic load segmentation identification in independent local power grid stability control according to claim 1, characterized in that, The types of components include: inter-station tie lines, main transformers, loads, busbars, circuit breakers, and disconnect switches.

4. In the independent local power grid stability control automatic load segmentation identification method according to claim 1, in step S3, when judging the operation and shutdown status of inter-station tie lines and main transformers within the station, an operation and shutdown criterion combining electrical quantities and circuit breaker location information is adopted, or a pure electrical quantity operation and shutdown criterion can be adopted according to actual conditions.

5. In the independent local power grid stability control automatic load segmentation identification method according to claim 1, in step S3, when performing topology identification on the substation, the bus section of the inter-station tie line is determined according to the on / off status of the inter-station tie line and the location information of the disconnecting switch in the corresponding bay; the area where the high-voltage side busbar of the substation is located is determined according to the location information of the high-voltage side bus tie bay circuit breaker and disconnecting switch; the area where the main transformer is located is determined according to the on / off status of the main transformer and the location information of the high-voltage side disconnecting switch of the main transformer; and the area where the medium- and low-voltage side busbar is located is determined according to the location information of the medium- and low-voltage side circuit breakers and disconnecting switches of the main transformer, combined with the location information of the medium- and low-voltage side bus tie bay circuit breakers and disconnecting switches.

6. The method for automatic load segmentation identification in independent local power grid stability control according to claim 1 or 2, characterized in that, Based on the importance of the load and the total available load capacity of different areas, if the load can be cut off both remotely and locally, only one set of load cutting priorities can be set. For situations where loads cannot be switched remotely but can be switched locally, load priorities can be set to remote load switching priority and local load switching priority.

7. An automatic load segmentation identification system for independent local power grid stability control, implementing the automatic load segmentation identification method for independent local power grid stability control according to any one of claims 1-6, characterized in that, include: The component library creation module is configured to create a component relationship library for the substation based on the substation's main wiring diagram, component information, and the connection relationships between components. The information acquisition module is configured to collect electrical quantity information of inter-station tie lines, main transformers within the station, and loads within the station, as well as the position information of all circuit breakers and disconnect switches in the station and the position information of switches on the opposite side. Topology analysis module: It is configured to determine the on / off status of inter-station tie lines, main transformers and loads within the station based on the collected electrical quantity information and switch position information, and to perform topology identification of substation components; The load segmentation identification module is configured to determine the status of all load segments in the substation based on the topology analysis results, and calculate the load shedding capacity of different load priorities in two segments by combining the load size, allowable load shedding status and load priority settings of different segments in the substation. Load selection module: It is configured to select the load in the corresponding area to be cut off based on the command of the upper-level stability control master station or substation, or the overload situation of the inter-station tie line or the main transformer. Load shedding execution module: configured to shed the load in the corresponding area according to the selection command.

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