A distributed carrying capacity evaluation method and system considering path tracing disambiguation and multi-level capacity mapping aggregation
By employing a real-time data-driven path tracing and multi-level capacity mapping aggregation method, the problem of path reconfiguration difficulties under dynamic grid switching is solved, enabling refined management and optimized resource allocation for distributed power source access.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- STATE GRID FUJIAN ELECTRIC POWER RES INST
- Filing Date
- 2026-04-17
- Publication Date
- 2026-07-14
Smart Images
Figure CN122393909A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of power system operation analysis and distribution network planning technology, specifically involving a distributed carrying capacity assessment method and system that takes into account path tracing disambiguation and multi-level capacity mapping and aggregation. This method is applicable to power grid areas with high distributed power penetration, complex grid topology and frequent operation mode switching, and is used to finely calculate the distributed power access capacity at the substation, bus, line and distribution area levels. Background Technology
[0002] Large-scale integration of distributed generation is a crucial path to building a new power system. Accurately assessing the carrying capacity of the distribution network is essential for guiding the orderly integration of distributed generation and ensuring the safe operation of the power grid. Traditional carrying capacity calculation methods heavily rely on static Geographic Information Systems (GIS) and existing network topology ledgers. When faced with frequent switching operations, untimely network topology updates, or redundant operational data, these methods often suffer from difficulties in physical path reconstruction, identification of redundant branches, and inaccurate capacity aggregation between different levels. This method, based on real-time operational data, achieves automatic path reconstruction and disambiguation through switch status tracing and power flow polarity comparison, and performs multi-level capacity mapping aggregation in conjunction with transformer operating status. This method overcomes the shortcomings of traditional static assessment methods, such as poor adaptability in dynamic network switching scenarios and the large workload of manual topology cleanup. It quantifies the remaining carrying capacity of equipment at each level, balancing computational timeliness and production accuracy requirements. Summary of the Invention
[0003] The purpose of this invention is to propose a distributed carrying capacity assessment method and system that takes into account path tracing disambiguation and multi-level capacity mapping and aggregation. This method performs reverse topology identification and multi-dimensional security verification based on the real-time operation data of the power grid, calculates the distributed access capacity of equipment at each voltage level and each power supply area, and is used to accurately identify power grid access bottlenecks, providing a basis for dispatching and planning departments to carry out orderly access of distributed power sources and flexible resource optimization.
[0004] To achieve the above objectives, the technical solution of the present invention is as follows:
[0005] This invention proposes a distributed carrying capacity assessment method that considers path tracing disambiguation and multi-level capacity mapping aggregation, comprising the following steps:
[0006] Step 1: Perform primary equipment topology tracing based on power grid operation data to construct a power supply physical path sequence;
[0007] Step 2: Select a typical day for measurement;
[0008] Step 3: Based on the grid operation data corresponding to the typical day, calculate the initial connectable capacity of the equipment, including the initial connectable capacity of individual equipment such as transformers and power supply lines at each voltage level.
[0009] Step 4: Based on the constructed power supply physical path sequence, identify and establish the physical association mapping between the segmented busbars and transformers at each voltage level, and perform aggregation logic processing according to the initial access capacity of the equipment to obtain the multi-level capacity mapping aggregation of the busbars;
[0010] Step 5: Based on the initial accessible capacity of the equipment and the multi-level capacity mapping of the busbar, capacity is aggregated from low voltage level to high voltage level along the power supply physical path sequence, and a list of accessible capacities covering the busbar, transformer and line is generated as the initial result of the distributed carrying capacity assessment. Based on the short-circuit impedance parameters of the nodes at each voltage level, the accessible capacity list is checked for short-circuit current and voltage deviation, and the accessible capacity of nodes that fail the check is corrected. The updated accessible capacity list is used as the final result of the distributed carrying capacity assessment.
[0011] Preferably, step 1 is as follows:
[0012] The real-time switching status of each level of switching equipment in the power grid operation data is extracted. The process is based on tracing back to the preset upstream power node as the termination condition. A reverse topology tracing algorithm is used to construct a basic physical connectivity sequence that is retrieved step by step from the distribution side node to the transmission side.
[0013] Based on the basic physical connectivity sequence, the rated voltage parameters of each node device are extracted, and the source tracing vector is set to search unidirectionally only in the direction of the node with increasing voltage level, shielding interference paths pointing to the same level load or low voltage level branches, thus completing the initial path screening.
[0014] For redundant paths identified after initial screening, the current vector or power flow direction of each branch at the branching node is extracted. By comparing the polarity of the power flow direction of each branch at the branching node, branches whose energy source direction is consistent with the direction of the busbar of the superior substation are selected as effective power supply paths. This achieves dynamic disambiguation of the operating path and completes the construction of the power supply physical path sequence.
[0015] Considering the problems of numerous physical redundant paths in the power grid and untimely static topology updates, the aforementioned dynamic disambiguation is based on the measured current vector or active power flow polarity. This ensures that the method still possesses the accuracy and universality of topology identification even when the power grid operation mode frequently changes.
[0016] Preferably, the selection of a typical day for measurement is as follows:
[0017] The time section with the minimum equivalent load during the midday period on weekdays in the measurement area is selected as the typical measurement day, where the equivalent load is the difference between the power load within the power supply range of the measurement area and the total output of distributed power sources.
[0018] Preferably, the initial access capacity of the measuring device is as follows:
[0019] Based on the power grid operation data corresponding to the calculated typical day, and taking a reverse load rate of no more than 80% as the safe operation threshold, the initial connectable capacity of individual equipment for transformers and power supply lines at each voltage level is calculated. :
[0020]
[0021] In the formula, The rated capacity of the equipment; This represents the minimum net equivalent load borne by the equipment during a typical day period. When the minimum net equivalent load is negative, its absolute value is taken.
[0022] For transformer groups or double-circuit line groups operating in parallel, the safe operating threshold is defined as the reverse load rate of the remaining components not exceeding 80% under the N-1 condition where any component is out of operation.
[0023] Preferably, the aggregation logic processing in step 4 is as follows:
[0024] For transformers operating in separate lines, the initial available capacity of the transformer is mapped to the available capacity of the busbar at this level;
[0025] For transformers operating in parallel, the sum of the initial accessible capacities of multiple transformers operating in parallel is mapped to the accessible capacity of the parallel busbar at this level.
[0026] Preferably, in step 5, the convergence principle is that the total capacity of the lower level does not exceed the capacity of the upper level equipment, and the capacity is aggregated from the low voltage level to the high voltage level along the power supply physical path sequence.
[0027] With the convergence principle of "the total capacity of the lower level does not exceed that of the upper level", it can accurately identify the access bottleneck from local branches to the whole station area, providing a basis for the power grid control department to achieve refined management and resource optimization of distributed power sources.
[0028] Preferably, in step 5, the short-circuit current check and correction are as follows:
[0029] For the current busbar verification node, the per-unit value of the busbar large-mode short-circuit impedance is used. Calculate the predicted short-circuit current after adding a distributed power source. :
[0030]
[0031] In the formula, Based on the basic short-circuit current, ; The rated voltage of the current verification node; Contribution coefficient to inverter short-circuit current;
[0032] like The rated breaking current of the circuit breaker configured at the current verification node exceeds the rated breaking current. Then according to and The excess ratio reduces the initial available capacity of the current verification node.
[0033] Preferably, in step 5, the voltage deviation verification and correction are as follows:
[0034] After completing the short-circuit current verification and making the first correction to the initial accessible capacity, the updated accessible capacity is used for the current bus verification node. As input, the per-unit value of the short-circuit impedance in the small bus mode is used. Calculate the maximum positive voltage deviation after adding a distributed power source. and maximum negative voltage deviation :
[0035]
[0036]
[0037] In the formula, For newly added distributed power sources, the rated power factor is... The maximum reactive power demand is as follows. ;
[0038] like If the sum of the deviations between δUL and the current voltage exceeds the preset standard limit, then it shall be handled in accordance with... The excess ratio of the sum of δUL and the current voltage deviation to the preset standard limit is used to reduce the access capacity of the current verification node after the update, and the access capacity list after the second update is used as the final distributed carrying capacity assessment result.
[0039] Preferably, the preset standard limits include: for voltages of 35kV and above, the sum of the absolute values of the positive and negative deviations shall not exceed 10% of the rated voltage; for voltages of 20kV and below, the positive and negative deviations shall be ±7% of the rated voltage.
[0040] In summary, this method extracts real-time operational data from the power grid dispatching system and achieves dynamic calculation of carrying capacity through automatic path tracing and automatic capacity aggregation. It is characterized by its ease of operation, lack of manual intervention, and high practicality, especially in areas with complex grid structures and large-scale distributed power generation.
[0041] The present invention also proposes a distributed carrying capacity assessment system that takes into account path tracing disambiguation and multi-level capacity mapping and aggregation, including a processor, a memory, and a computer program stored in the memory. When the processor executes the computer program, it specifically performs any of the steps in the above-mentioned distributed carrying capacity assessment method.
[0042] Compared with the prior art, the present invention has the following beneficial effects:
[0043] This invention addresses the challenges of path redundancy and untimely static topology updates caused by dynamic switching of power grid operation modes and changes in power flow direction. It proposes a distributed carrying capacity assessment method that incorporates path tracing and disambiguation, as well as multi-level capacity mapping and aggregation. Based on real-time power grid operation data, this method performs automatic path tracing and power flow direction disambiguation, achieving automatic logical aggregation of the connectable capacity of equipment at each level, including substations, buses, and transformers. It balances computational efficiency with the requirements of refined calculation accuracy in utilizing real-time data for dynamic grid reconfiguration and redundant data processing, providing a scientific basis for the orderly access of distributed power sources and the optimized allocation of scheduling resources. Attached Figure Description
[0044] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation
[0045] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.
[0046] This invention addresses the challenges of path redundancy and untimely static topology updates caused by dynamic switching of power grid operation modes and changes in power flow direction. It proposes a distributed carrying capacity assessment method that incorporates path tracing and disambiguation, as well as multi-level capacity mapping and aggregation. By extracting real-time operational data from the power grid dispatching system, it performs automatic path reconstruction and disambiguation, and automatically generates a list of available new access capacities for substations, buses, and transformers. This significantly reduces manual calculation workload, improves computational efficiency, and provides a scientific basis for refined management and optimized allocation of dispatching resources for distributed power sources.
[0047] Reference Figure 1 A distributed carrying capacity assessment method that considers path tracing disambiguation and multi-level capacity mapping aggregation is described in the following steps:
[0048] Step 1: Identification of primary equipment topology based on operational data.
[0049] 1) Initial screening of physical paths: Real-time acquisition of remote signaling data of switchgear at all levels in candidate paths from the node to be checked to the 220kV side. If a branch path switch is identified as being in an "open" state, the branch is determined to be an electrical disconnection point and is eliminated, thus constructing a basic physical connectivity sequence for step-by-step retrieval from the distribution side node to the transmission side.
[0050] 2) Source tracing direction constraint: Extract the rated voltage parameters of each node device, set the source tracing vector to only search in the direction of the node with increasing voltage level (such as 10kV→35kV / 110kV→220kV), and automatically block interference paths pointing to the same level load or other low voltage level branches.
[0051] 3) Dynamic disambiguation: For redundant paths identified after initial screening, the current vector or active power flow direction of each branch at the branching node is extracted in real time. By comparing the polarity of the power flow direction, branches whose energy source direction is consistent with that of the upstream 220kV bus are selected as valid power supply paths. When the current node is identified as a 220kV bus node, the path is determined to be closed.
[0052] Step 2: Calculate the selection of typical days.
[0053] The time section with the smallest equivalent load and the largest output of distributed power sources in the measurement area (district or city-level power supply area) during the midday period (10:00-14:00) on weekdays is selected as the typical measurement day.
[0054] equivalent load The calculation formula is:
[0055]
[0056] In the formula, To calculate the real-time power load within the power supply area; This represents the total real-time output of distributed power sources within the region. (Selection) The cross-section with the largest negative value and the largest absolute value best reflects the extreme pressure scenario of reverse power transmission from the power grid.
[0057] Step 3: Calculation of the initial connectable capacity of the equipment.
[0058] 1) Reverse load rate constraint: The safe operating threshold is that the reverse load rate of the equipment does not exceed 80%; if the equipment is a parallel-operating transformer or a double-circuit line, the safe operating threshold is that the reverse load rate of the equipment in the N-1 state does not exceed 80%.
[0059] 2) Initial capacity calculation: Calculate the initial connectable capacity Pm of individual transformers and power supply lines at each voltage level:
[0060]
[0061] In the formula, Rated capacity of the equipment (unit: MVA); The minimum net equivalent load borne by the equipment during a typical daytime period (a positive value is taken if it is a reverse power flow). For main transformers operating in parallel, their rated capacity is corrected according to the remaining effective capacity under the N-1 principle.
[0062] Step 4: Multi-level capacity mapping and aggregation based on power supply physical paths.
[0063] 1) Physical association mapping: Based on the physical path sequence constructed in step 1, establish the operation status mapping between the bus and the transformer.
[0064] 2) Collection logic processing:
[0065] a. For transformers operating in separate units (transformers directly electrically connected to a certain section of the busbar within this station are considered transformers operating in separate units), the initial connectable capacity of the transformer will be... This is mapped to the access capacity of the corresponding level of the busbar on that side;
[0066] b. For transformers operating in parallel, identify the numbers of all associated parallel transformers and sum their initial accessible capacities as the accessible capacity of that parallel-side bus level.
[0067] This step enables the automatic conversion of capacity from physical devices (transformers) to logical nodes (buses), providing basic data for global aggregation.
[0068] Step 5: Summarize the load-bearing capacity results and verify the safety.
[0069] 1) Capacity aggregation and summarization: The process proceeds from low voltage level to high voltage level along the physical path sequence, with the convergence principle that "the total capacity of the lower level does not exceed the capacity of its directly associated upper level equipment", and a list of accessible capacities covering busbars, transformers and lines is generated.
[0070] 2) Short-circuit current check:
[0071] For the current busbar verification node, the per-unit value of the busbar large-mode short-circuit impedance is used. (Base capacity is 100MVA), calculate the predicted short-circuit current after the addition of a distributed power source. :
[0072]
[0073] In the formula, Based on the basic short-circuit current, ; This is the rated voltage; the coefficient 1.5 is a conservative estimate considering the contribution of the inverter's short-circuit current. If... Exceeding the rated breaking current of the circuit breaker Then according to and The excess ratio reduces the initial available capacity of the current verification node.
[0074] 3) Voltage deviation verification:
[0075] After completing the short-circuit current verification and making the first correction to the initial accessible capacity, the updated accessible capacity is used for the current bus verification node. As input, the per-unit value of the short-circuit impedance in the small bus mode is used. (Base capacity is 100MVA), calculate the maximum new positive voltage deviation. :
[0076]
[0077] Added maximum negative voltage deviation :
[0078]
[0079] In the formula, The maximum reactive power demand of the newly added power source at the rated power factor (0.98) is given. .
[0080] like , If the sum of the deviations from the current voltage exceeds the standard limit (for 35kV and above, the sum of the absolute values of positive and negative deviations shall not exceed 10% of the rated voltage; for 20kV and below, the positive and negative deviations shall be ±7% of the rated voltage), then it shall be handled according to... , The excess ratio of the sum of the current voltage deviations to the preset standard limit is used to reduce the updated access capacity of the current verification node, and the updated access capacity list is used as the final distributed carrying capacity assessment result.
[0081] In summary, to address the challenges of path redundancy and untimely static topology updates caused by dynamic switching of power grid operation modes and changes in power flow direction, the following methods are employed: First, equipment parameters are entered and real-time operating data is extracted, and path tracing is performed using switch status. Second, dynamic disambiguation is performed by comparing the polarity of measured power flow to pinpoint the effective physical power supply path. Next, the initial capacity of individual equipment under safety constraints is calculated on a typical day with the minimum equivalent load. Subsequently, multi-level capacity mapping and aggregation are performed based on the main transformer's operating status, and hierarchical convergence is carried out along the path. Finally, after safety checks on short-circuit current and voltage deviations, iterative corrections are made to obtain the distributed carrying capacity assessment results at the substation, bus, and line levels. This approach balances computational efficiency with the requirements of refined calculation accuracy, providing a scientific basis for the orderly access of distributed power sources and the optimized allocation of scheduling resources.
[0082] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.
Claims
1. A distributed carrying capacity assessment method considering path tracing disambiguation and multi-level capacity mapping aggregation, characterized in that, Includes the following steps: Step 1: Perform primary equipment topology tracing based on power grid operation data to construct a power supply physical path sequence; Step 2: Select a typical day for measurement; Step 3: Based on the grid operation data corresponding to the typical day, calculate the initial connectable capacity of the equipment, including the initial connectable capacity of individual equipment such as transformers and power supply lines at each voltage level. Step 4: Based on the constructed power supply physical path sequence, establish the physical association mapping between the bus and the transformer, and perform aggregation logic processing according to the initial access capacity of the equipment to obtain the multi-level capacity mapping aggregation of the bus. Step 5: Based on the initial access capacity of the equipment and the multi-level capacity mapping of the bus, the capacity is aggregated from low voltage level to high voltage level along the power supply physical path sequence, and a list of access capacity covering the bus, transformer and line is generated as the initial result of the distributed carrying capacity assessment. The available capacity list is checked for short-circuit current and voltage deviation. The available capacity of nodes that fail the check is corrected, and the updated available capacity list is used as the final distributed carrying capacity assessment result.
2. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that, Step 1 is described in detail as follows: Extract the real-time opening and closing status of switching equipment at all levels from the power grid operation data, and construct a basic physical connectivity sequence for retrieval from the distribution side node to the transmission side, with the retrieval tracing back to the preset upstream power node as the termination condition; Based on the basic physical connectivity sequence, the rated voltage parameters of each node device are extracted, and the source tracing vector is set to search unidirectionally only in the direction of the node with increasing voltage level, shielding interference paths pointing to the same level load or low voltage level branches, thus completing the initial path screening. For redundant paths identified after initial screening, the power flow polarity of each branch at the branching node is compared to select branches whose energy source direction is consistent with the direction of the busbar of the superior substation as effective power supply paths, thus completing the construction of the power supply physical path sequence.
3. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that... The specific selection and calculation of typical days are as follows: The time section with the minimum equivalent load during the midday period on weekdays in the measurement area is selected as the typical measurement day, where the equivalent load is the difference between the power load within the power supply range of the measurement area and the total output of distributed power sources.
4. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that... The initial access capacity of the measurement device is as follows: Based on the power grid operation data corresponding to the calculated typical day, and taking a reverse load rate of no more than 80% as the safe operation threshold, the initial connectable capacity of individual equipment for transformers and power supply lines at each voltage level is calculated. : In the formula, The rated capacity of the equipment; This represents the minimum net equivalent load borne by the equipment during a typical day period. When the minimum net equivalent load is negative, its absolute value is taken. For transformer groups or double-circuit line groups operating in parallel, the safe operating threshold is defined as the reverse load rate of the remaining components not exceeding 80% under the N-1 condition where any component is out of operation.
5. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that... The specific collection logic processing in step 4 is as follows: For transformers operating in separate lines, the initial available capacity of the transformer is mapped to the available capacity of the busbar at this level; For transformers operating in parallel, the sum of the initial accessible capacities of multiple transformers operating in parallel is mapped to the accessible capacity of the parallel busbar at this level.
6. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that, In step 5, the convergence principle is that the total capacity of the lower level does not exceed the capacity of the upper level equipment, and the capacity is aggregated from the low voltage level to the high voltage level along the power supply physical path sequence.
7. The distributed carrying capacity assessment method according to claim 1, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that... In step 5, the short-circuit current check and correction are as follows: For the current busbar verification node, the per-unit value of the busbar large-mode short-circuit impedance is used. Calculate the predicted short-circuit current after adding a distributed power source. : In the formula, Based on the basic short-circuit current, ; The rated voltage of the current verification node; Contribution coefficient to inverter short-circuit current; like The rated breaking current of the circuit breaker configured at the current verification node exceeds the rated breaking current. Then according to and The excess ratio reduces the initial available capacity of the current verification node.
8. The distributed carrying capacity assessment method according to claim 7, which considers path tracing disambiguation and multi-level capacity mapping aggregation, is characterized in that... In step 5, the voltage deviation verification and correction are as follows: After completing the short-circuit current verification and making the first correction to the initial accessible capacity, the updated accessible capacity is used for the current bus verification node. As input, the per-unit value of the short-circuit impedance in the busbar small mode is used. Calculate the maximum positive voltage deviation after adding a distributed power source. and maximum negative voltage deviation : In the formula, For newly added distributed power sources, the rated power factor is... The maximum reactive power demand is as follows. ; like If the sum of the deviations between δUL and the current voltage exceeds the preset standard limit, then it shall be handled in accordance with... The excess ratio of the sum of δUL and the current voltage deviation to the preset standard limit is used to reduce the access capacity of the current verification node after the update, and the access capacity list after the second update is used as the final distributed carrying capacity assessment result.
9. A distributed carrying capacity assessment method considering path tracing disambiguation and multi-level capacity mapping and aggregation as described in claim 8, characterized in that, The preset standard limits include: for voltages of 35kV and above, the sum of the absolute values of the positive and negative deviations shall not exceed 10% of the rated voltage; for voltages of 20kV and below, the positive and negative deviations shall be ±7% of the rated voltage.
10. A distributed carrying capacity assessment system that considers path tracing disambiguation and multi-level capacity mapping aggregation, characterized in that, It includes a processor, a memory, and a computer program stored in the memory. When the processor executes the computer program, it specifically performs the steps in the distributed carrying capacity assessment method as described in any one of claims 1-9.