Substation 10kV side low voltage busbar connection structure and corresponding planning and transformation method

Abstract

The present invention provides a low-voltage busbar connection structure on the 10kV side of a substation, characterized by comprising: in a 110kV substation, the 10kV side includes six 10kV busbar sections, each busbar section adopts a ring connection method, and each busbar section is powered by two main transformers; two 10kV lines are used in a closed loop on each busbar section, and the average line load rate is controlled below 50%; wherein, a connecting circuit breaker is provided between the busbars of two adjacent ring networks, and the closed loop unit of each ring network connects with the closed loop unit of the other substation via a connecting line to achieve uninterrupted power supply in the event of a line failure in the ring network, and the load of the ring network is completely transferred to another ring network via the connecting line. The present invention also provides a corresponding planning and transformation method. Implementing the present invention can increase the total number of outgoing lines on the 10kV side of the substation, improve the power supply capacity of the entire network, and thus improve the utilization rate of power grid equipment.

Description

Technical Field

[0001] The present invention relates to the technical field related to substations, and in particular to a 10kV-side low-voltage busbar connection structure of a substation and a corresponding planning and transformation method. Background Art

[0002] With the continuous development of large cities and the growth of high-reliability loads in cities, how to utilize scarce land resources and limited grid equipment assets based on the existing substations and 10kV power supply system to achieve the goal of improving the reliability and power supply capacity of the grid.

[0003] like Figure 1 Figure 2 shows a busbar connection diagram for an existing 110kV substation. As can be seen, in a conventional 110kV substation (taking a common single 63MVA main transformer as an example), the 10kV side generally uses a four-section busbar connection. Each main transformer has 16 10kV outgoing lines on the low-voltage side, so a substation with three main transformers has a maximum of 48 10kV outgoing lines. Furthermore, in existing urban power grid connections, various 10kV lines are often connected in N-supply, one-backup (N=2 or 3) or single-ring networks.

[0004] During periods of rapid load growth in urban power grids, the 10kV outgoing lines at a single substation often lack sufficient spacing, hindering the connection of new loads to the grid. This often necessitates the construction of new substations or extensive line load adjustments to increase or reduce the number of 10kV outgoing lines. This model wastes land resources for substation construction and can make load adjustment between different 10kV lines difficult. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the present invention provides a low-voltage busbar connection structure on the 10kV side of the substation and a corresponding planning and transformation method, which can increase the total number of outgoing lines on the 10kV side of the substation, improve the power supply capacity of the entire network, and thus improve the utilization rate of the power grid equipment.

[0006] To solve the above technical problems, as one aspect of the present invention, a substation 10kV side low-voltage busbar connection structure is provided, which includes:

[0007] In a 110kV substation, the 10kV side includes six 10kV busbar sections. Each busbar section adopts a ring connection method and is powered by two main transformers. The main transformer capacity is configured as N-1.

[0008] Two 10kV lines are used in a closed loop on each busbar section, with the average line load rate controlled below 50%. A connecting circuit breaker is installed between the busbars of two adjacent ring networks. The closing unit of each ring network is connected to the closing units of other substations via a connecting line to achieve uninterrupted power supply in the event of a fault in the ring network line. The load of the ring network is completely transferred to the other ring network via the connecting line.

[0009] Accordingly, the present invention also provides a planning and reconstruction method based on the low-voltage busbar connection structure on the 10kV side of the substation, which comprises the following steps:

[0010] Step S10: selecting multiple target substations in the regional power grid that need to be renovated, and determining whether each target substation meets specific renovation conditions, wherein the renovation conditions at least include whether the load transfer conditions during the power outage construction period are met;

[0011] Step S11: For the multiple target substations requiring transformation, comprehensively determine whether there is space for power station optimization transformation or construction in the selected regional power grid; compare the existing wiring diagram of each target substation with the aforementioned wiring structure to determine the maximum capacity of the load that can be connected to each target substation, and determine its 10kV line load distribution plan based on reasonable line wiring and line load rate;

[0012] Step S12: Establish a 10kV side transformation project library for substations based on all target substations that have completed the 10kV line load distribution plan, evaluate each target substation in the transformation project library, determine the implementation effect evaluation results of each substation optimization and transformation project, and sort them to form a time-series list of recommended projects;

[0013] Step S13: transform the target substation in the project library according to the recommended project sequence to obtain the network structure of the corresponding target substation.

[0014] Preferably, the step S11 further includes:

[0015] For each target substation, obtain its 10kV line load information, analyze whether it has the conditions for load transfer during power outages, and analyze whether its low-voltage side 10kV busbar has the conditions for load transfer to the busbar of the adjacent target substation;

[0016] Obtain the current layout and available land area of each target substation, and assess whether the substation has the physical conditions for optimization and transformation;

[0017] Based on the historical load and expected load development target of each target substation's 10kV line, assess whether the substation's 10kV line has the operating conditions for power outage and load transfer;

[0018] After all the above conditions are met, the planning drawings of the 10kV busbar and distribution equipment room layout of each target substation are adjusted. Combined with the expected load development target, the maximum capacity of the load that can be connected to the target substation is determined. Based on the above-mentioned wiring structure, the 10kV line load distribution of each target substation is determined according to reasonable line wiring and line load rate.

[0019] Preferably, in step S12, evaluating each target substation in the transformation project library specifically includes:

[0020] For each target substation in the renovation project library, scores are given based on four dimensions: load power supply conditions around the substation, load development conditions, upper-level power supply conditions, and important users of substation power supply. Weighted processing is performed based on the weight of each dimension to obtain an implementation effect evaluation value. The projects are sorted according to the implementation effect evaluation value to obtain a chronological list of recommended projects.

[0021] The implementation of the embodiments of the present invention has the following beneficial effects:

[0022] The present invention provides a 10kV-side low-voltage busbar connection structure for a substation and a corresponding planning and transformation method. In the busbar connection structure, by adding a new 10kV busbar segment to the substation and optimizing and adjusting the 10kV connection ring connection operation mode, the 10kV outgoing line capacity of the substation is increased without increasing the substation's land area, thereby solving the problem of insufficient 10kV outgoing line spacing in urban substations. This can effectively save construction land resources, intensively utilize land resources, and improve the utilization rate of power grid assets and equipment.

[0023] At the same time, this embodiment, based on existing medium-voltage distribution network planning optimization methods, analyzes the grid's substation renovation space, the load power supply situation around the substation, load development, upstream power supply conditions, and key substation power users, a total of four dimensions. This allows for an evaluation of the implementation effectiveness of substation optimization and renovation projects and a recommended project sequence. This can avoid the high coordination difficulties associated with independent substation site selection, such as land acquisition and demolition. It can also address the land shortages associated with large urban power grid construction, fully consider the layout and renovation conditions of substations, clarify the implementation path for substation renovation, and improve the feasibility of planning schemes. Furthermore, it can comprehensively improve the load power supply capacity of regional power substations, further enhancing the scientific nature of 10kV distribution network planning technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0025] Figure 1 This is a schematic diagram of the low-voltage busbar connection structure on the 10kV side of an existing substation;

[0026] Figure 2 A schematic structural diagram of an embodiment of a 10kV-side low-voltage busbar connection structure for a substation provided by the present invention;

[0027] Figure 3 The present invention provides a schematic diagram of the main process of an embodiment of a method for planning and reconstructing a low-voltage busbar connection structure on the 10kV side of a substation. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0029] like Figure 2 FIG. 1 is a schematic structural diagram of an embodiment of a 10kV-side low-voltage busbar connection structure of a substation provided by the present invention; in this embodiment, the 10kV-side low-voltage busbar connection structure of the substation includes:

[0030] The 10kV side of the 110kV substation includes six 10kV busbar sections, namely 1AM, 1BM, 2AM, 2BM, 3AM, and 3BM in the figure. Each busbar section adopts a ring connection method, in which busbars 1AM and 1BM are connected to transformer 1#, busbars 2AM and 2BM are connected to transformer 2#, and busbars 3AM and 3BM are connected to transformer 3#. Since busbars 1BM and 2AM, busbars 2BM and 3AM, and busbars 3BM and 1AM are connected by tie circuit breakers (i.e., S21, S23, and S13), each busbar section can be supplied by two main transformers. In this embodiment, the main transformer capacity is configured as N-1.

[0031] Specifically, two 10kV lines are used in a closed loop on each busbar section, and the average load rate of the line is controlled below 50%. A connecting circuit breaker (such as S21, S23, and S13) is set between the busbars of two adjacent ring networks. The closing unit of each ring network is connected to the closing unit of other substations through a connecting line to achieve uninterrupted power supply when a line failure occurs in the ring network. The load of the ring network is completely transferred to another ring network through the connecting line.

[0032] As can be understood, since the tie lines originate from different substations, the risk of excessive short-circuit current on the low-side of the substation can be avoided. In the event of a line fault, uninterrupted power transfer is possible, ensuring extremely high power supply reliability, while meeting the N-1 safety standard and the busbar's N-1. In the event of a single busbar outage, if one of the rings loses power completely, the tie line can be used to transfer the entire load of the faulty ring to another ring, as the average line load is kept below 50%. For example, if the ring containing bus 1AM loses power (i.e., fuse S01A between 1AM and transformer 1# is disconnected), the entire load of the ring containing 1AM can be transferred to the ring containing bus 3BM, or to other rings connected to the tie line. If bus 1AM fails, the tie line can also be used to transfer the load to other rings.

[0033] As can be understood, compared to existing technologies, the 10kV busbar ring connection scheme provided by this invention can add approximately 20 10kV outgoing lines to the substation without increasing the substation's footprint. This can alleviate the shortcomings of traditional substations, such as insufficient 10kV bay resources and a power supply reliability that fails to meet the power supply requirements of high-reliability load areas. It can also effectively conserve construction land resources, intensively utilize land resources, and improve the utilization rate of grid assets and equipment.

[0034] The present invention can be applied to the planning and construction of 110kV and below distribution networks in urban core development areas, especially in the planning and construction of smart grids in urban power grids with high power load density.

[0035] like Figure 3 FIG. 1 shows a schematic diagram of the main process of an embodiment of a method for planning and reconstructing a low-voltage busbar connection structure on the 10 kV side of a substation provided by the present invention, which includes the following steps:

[0036] Step S10: Select multiple target substations in the regional power grid that require renovation, and determine whether each target substation meets specific renovation conditions. The renovation conditions include at least whether load transfer conditions are met during the power outage construction period; and may also include other factors such as substation layout.

[0037] Step S11: For the plurality of target substations requiring transformation, comprehensively determine whether there is space for power station optimization, transformation, or construction in the selected regional power grid; compare the existing wiring diagram of each target substation with the wiring structure described in claim 1, determine the maximum capacity of the load that can be connected to each target substation, and determine its 10 kV line load distribution plan based on reasonable line wiring and line load rate;

[0038] Specifically, in one example, step S11 further includes:

[0039] For each target substation, obtain its 10kV line load information, analyze whether it has the conditions for load transfer during power outages, and analyze whether its low-voltage side 10kV busbar has the conditions for load transfer to the busbar of the adjacent target substation;

[0040] Obtain the current layout and available land area of each target substation, and assess whether the substation has the physical conditions for optimization and transformation;

[0041] Based on the historical load and expected load development target of each target substation's 10kV line, assess whether the substation's 10kV line has the operating conditions for power outage and load transfer;

[0042] After all the above conditions are met, the 10kV busbar and distribution equipment room layout of each target substation is adjusted, and the maximum capacity of the load that can be connected to the target substation is determined in combination with the expected load development target. Figure 1 The wiring structure described in the above is used to determine the 10kV line load distribution of each target substation based on reasonable line wiring and line load rate.

[0043] Step S12: Establish a 10kV side transformation project library for substations based on all target substations that have completed the 10kV line load distribution plan, evaluate each target substation in the transformation project library, determine the implementation effect evaluation results of each substation optimization and transformation project, and sort them to form a time-series list of recommended projects;

[0044] In a specific example, in step S12, evaluating each target substation in the transformation project library specifically includes:

[0045] For each target substation in the renovation project library, scores are given based on four dimensions: load power supply conditions around the substation, load development conditions, upper-level power supply conditions, and important users of substation power supply. Weighted processing is performed based on the weight of each dimension to obtain an implementation effect evaluation value. The projects are sorted according to the implementation effect evaluation value to obtain a chronological list of recommended projects.

[0046] Specifically, the four dimensions can be divided into 10 levels, each level corresponds to a score, and the weight corresponding to each dimension is pre-set; the score of each dimension of each target substation is obtained during the evaluation; then the score of each dimension is multiplied by the weight, and the sum is taken to obtain the implementation effect evaluation value.

[0047] Step S13: transform the target substation in the project library according to the recommended project sequence to obtain the network structure of the corresponding target substation.

[0048] For more details, please refer to the above Figure 2 The description is not detailed here.

[0049] The implementation of the embodiments of the present invention has the following beneficial effects:

[0050] The present invention provides a 10kV-side low-voltage busbar connection structure for a substation and a corresponding planning and transformation method. In the busbar connection structure, by adding a new 10kV busbar segment to the substation and optimizing and adjusting the 10kV connection ring connection operation mode, the 10kV outgoing line capacity of the substation is increased without increasing the substation's land area, thereby solving the problem of insufficient 10kV outgoing line spacing in urban substations. This can effectively save construction land resources, intensively utilize land resources, and improve the utilization rate of power grid assets and equipment.

[0051] At the same time, this embodiment, based on existing medium-voltage distribution network planning optimization methods, evaluates the implementation effectiveness of substation optimization and renovation projects based on four dimensions: the power supply space for substation renovations, the load power supply situation around the substation, load development, upstream power supply conditions, and key users of the substation power supply. This approach also provides a recommended project schedule. This approach avoids the high coordination challenges associated with independent substation site selection, such as land acquisition and demolition. It also addresses the land shortage associated with large urban power grid construction, fully considers the layout and renovation conditions of substations, clarifies the implementation path for substation renovation, and improves the feasibility of planning schemes. Furthermore, it comprehensively improves the load power supply capacity of regional power substations, further enhancing the scientific nature of 10kV distribution network planning technology. Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, apparatus, or computer program products. Therefore, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0052] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0053] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A planning and reconstruction method based on the low-voltage busbar connection structure on the 10kV side of a substation, characterized in that: The substation 10kV side low-voltage busbar connection structure includes: In a 110kV substation, the 10kV side includes six 10kV busbar sections. Each busbar section adopts a ring connection method and is powered by two main transformers. The main transformer capacity is configured as N-1. Two 10kV lines are used in a closed loop on each busbar section, with the average line load rate controlled below 50%. A connecting circuit breaker is installed between the busbars of two adjacent ring networks. The closing unit of each ring network communicates with the closing units of other substations via a connecting line. This allows for uninterrupted power transfer in the event of a fault in the ring network, transferring the entire load of the ring network to the other ring network via the connecting line. The method comprises the following steps: Step S10: selecting multiple target substations in the regional power grid that need to be renovated, and determining whether each target substation meets specific renovation conditions, wherein the renovation conditions at least include whether the load transfer conditions during the power outage construction period are met; Step S11: For the multiple target substations that need to be renovated, comprehensively determine whether there is space for power station optimization and renovation or construction in the selected regional power grid; determine the maximum capacity of the load that can be connected to each target substation, and determine its 10kV line load distribution plan based on reasonable line connection and line load rate; Step S12: Establish a 10kV side transformation project library for substations based on all target substations that have completed the 10kV line load distribution plan, evaluate each target substation in the transformation project library, determine the implementation effect evaluation results of each substation optimization and transformation project, and sort them to form a time-series list of recommended projects; Step S13, transforming the target substation in the project library according to the recommended project sequence to obtain the network structure of the corresponding target substation; In step S12, the evaluation of each target substation in the transformation project library specifically includes: For each target substation in the renovation project library, scores are given based on four dimensions: load power supply conditions around the substation, load development conditions, upper-level power supply conditions, and important users of substation power supply. Weighted processing is performed based on the weight of each dimension to obtain an implementation effect evaluation value. The projects are sorted according to the implementation effect evaluation value to obtain a chronological list of recommended projects.

2. The method according to claim 1, wherein The step S11 further comprises: For each target substation, obtain its 10kV line load information, analyze whether it has the conditions for load transfer during power outages, and analyze whether its low-voltage side 10kV busbar has the conditions for load transfer to the busbar of the adjacent target substation; Obtain the current layout and available land area of each target substation, and assess whether the substation has the physical conditions for optimization and transformation; Based on the historical load and expected load development target of each target substation's 10kV line, assess whether the substation's 10kV line has the operating conditions for power outage and load transfer; After all the above conditions are met, the planning drawings of the 10kV busbar and distribution device room layout of each target substation are adjusted. Combined with the expected load development target, the maximum capacity of the load that can be connected to the target substation is determined. Based on the low-voltage busbar connection structure on the 10kV side of the substation, the 10kV line load distribution of each target substation is determined according to reasonable line wiring and line load rate.

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