Economic allocation method and system for centralized configuration of new energy gathering station network SVG
Patent Information
- Application Number
- CN202610882577.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-18
- Publication Date
- 2026-09-15
Smart Images
Figure CN122760145A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of new energy power generation grid connection technology, specifically involving a construction cost allocation method and system for a new energy multi-site aggregation system when grid-type static var generators (SVG) are centrally configured at the aggregation station. Background Technology
[0002] With the large-scale centralized grid connection of new energy power generation, in order to fully utilize wind and solar resources, wind power, photovoltaic and other new energy power plants often undergo multi-stage voltage boosting before being connected to 500kV hub substations via long-distance transmission lines. This centralized transmission method results in a low ratio (SCR) between the system short-circuit capacity at the power plant's grid connection point and the rated power of the new energy power generation. When the SCR falls below a certain critical value, the AC grid exhibits weak grid characteristics, easily leading to a series of safety and stability problems such as transient overvoltage, voltage collapse, sub- / super-synchronous oscillations, and phase-locked loop instability, severely restricting the transmission capacity of new energy and the reliability of grid operation.
[0003] To address the weak grid problem caused by insufficient short-circuit ratio, traditional solutions often involve distributing dynamic reactive power compensation devices, such as static var generators (SVG) or synchronous condensers, at various renewable energy power plants. While this approach provides localized support for individual power plants, it has significant limitations: firstly, the large number of devices leads to high overall investment, construction, and maintenance costs; secondly, in densely populated areas, the coordination and control between compensation devices is complex, resulting in low overall utilization efficiency. In recent years, utilizing 500kV substations to centrally configure large-capacity grid-type SVG has become a more economical alternative. Grid-type SVG can simulate the external characteristics of synchronous generators, autonomously constructing voltage amplitude and frequency, providing strong reactive current and short-circuit capacity support during disturbances, effectively increasing the system short-circuit capacity of the substation bus, thereby improving the grid-connected short-circuit ratio of multiple connected power plants at once and significantly reducing the investment required for distributed installations.
[0004] However, centralized deployment of grid-type SVG faces a practical problem: who bears the construction cost, and how to fairly distribute it among multiple beneficiary power plants? Because different power plants have different original short-circuit ratios, their voltage support benefits from centralized SVG also vary significantly—power plants with lower original short-circuit ratios benefit more significantly; while power plants with relatively ample short-circuit ratios benefit very little or nothing. Simply allocating the cost proportionally to installed capacity, or using an equal allocation method, would result in smaller beneficiaries indirectly subsidizing larger beneficiaries, failing to accurately reflect the actual benefit received by each power plant. This lack of fairness would be difficult for investors to accept, hindering project implementation.
[0005] Currently, there is no objective, quantitative, and readily acceptable allocation method in engineering. Some existing methods attempt to allocate costs based on factors such as electrical distance and changes in short-circuit current at the connection point, but these methods suffer from drawbacks such as computational complexity, lack of intuitive physical meaning, and difficulty in data acquisition. Therefore, there is an urgent need to propose an economical allocation method based on the electrical characteristics of the power station itself, with transparent calculation criteria and reproducible results, to support the commercial application of SVG grids in renewable energy aggregation areas. Summary of the Invention
[0006] To address the aforementioned technical problems, the purpose of this invention is to provide an economical cost-sharing method and system for centralized configuration of SVG in new energy collection stations. This method uses the short-circuit ratio of each station and its critical value deficit as the basis for cost-sharing. The larger the deficit, the higher the cost-sharing, thus accurately reflecting the fair principle of "the more you benefit, the more you bear." Moreover, the calculation basis relies entirely on the electromechanical transient program commonly used in power grid planning and operation, and the results are objective and reproducible.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: an economical cost-sharing method for centralized configuration of SVG in new energy collection station network, comprising the following steps: Step 1: Determine the range of candidate power stations to participate in the cost-sharing and obtain the rated power of each power station.
[0008] and the selected short-circuit ratio assessment point and the corresponding critical short-circuit ratio value
[0009] Step 2: Establish a regional power grid model in the electromechanical transient simulation program, including the collecting station bus, each new energy power station and its grid-connected components. Using the program's built-in dedicated short-circuit ratio calculation module, calculate and output the actual short-circuit ratio of each power station at the assessment point. ; Step 3: Select the stations whose actual short-circuit ratio is lower than the corresponding critical value as the allocation targets, and calculate the short-circuit ratio deficit for each allocation target. ; Step 4: Using the sum of the short-circuit ratio deficits of all the aforementioned allocation objects as the denominator and the short-circuit ratio deficit of a single station as the numerator, calculate the cost allocation ratio for each allocation object.
[0010] Step 5: Based on the stated cost allocation ratio The total cost of centralized configuration of SVG network Determine the expenses to be borne by each party. .
[0011] Furthermore, in step 1, the assessment point can be uniformly taken as the high-voltage side grid connection point of the step-up transformer of each station, and the corresponding critical short-circuit ratio is set to 2.0; or the assessment point can be taken as the low-voltage side of the step-up transformer according to the inverter's withstand capability, and the corresponding critical short-circuit ratio is set to 1.5; when different stations use different assessment points, the short-circuit ratio deficit of each station needs to be uniformly converted to the same assessment benchmark before the ratio calculation is performed.
[0012] Furthermore, the electromechanical transient simulation program in step 2 is PSD-BPA or PSASP, whose dedicated short-circuit ratio calculation module can directly output the bus short-circuit capacity or short-circuit ratio, and supports the calculation of the multi-infeed short-circuit ratio (MRSCR) considering the interaction effects of multiple substations; at this time, the multi-infeed short-circuit ratio is used as the actual short-circuit ratio.
[0013] MR This can more accurately reflect the mutual influence between stations.
[0014] Furthermore, in step 2, the actual short-circuit ratio is the ratio of the system short-circuit capacity calculated at the assessment point to the rated power of the power station.
[0015] The actual short-circuit ratio is the multi-infeed short-circuit ratio (MRSCR) output by the electromechanical transient simulation program, which reflects the electrical interaction between various stations.
[0016] Furthermore, in step 4, a relative deficit can also be used. The allocation ratio is calculated to replace the absolute deficit calculation, in order to adapt to situations where different thresholds coexist.
[0017] Furthermore, when a new power station is connected or the power grid structure undergoes significant changes, steps 2 to 5 can be repeated to dynamically verify and adjust the allocation ratio of each power station.
[0018] Furthermore, the total cost of the centralized configuration of the grid-connected SVG includes the cost of the grid-connected SVG equipment, the cost of the step-up transformer and power distribution equipment, the cost of civil engineering and installation, and the cost of commissioning and grid connection testing. This invention also provides an economical cost-sharing system for centralized configuration of SVG in new energy collection station network, used to implement the above method, including: The parameter configuration module is used to obtain the rated power of each new energy power station and determine the assessment point of the short-circuit ratio of each power station and the corresponding critical short-circuit ratio value. The short-circuit ratio calculation module is used to establish a regional power grid model including the collection station bus and each new energy power station in the electromechanical transient simulation program. Using the dedicated short-circuit ratio calculation module built into the electromechanical transient simulation program, the module calculates and outputs the actual short-circuit ratio of each power station at the assessment point. The apportionment object screening module is used to screen out the stations whose actual short-circuit ratio is lower than the corresponding critical short-circuit ratio as apportionment objects, and calculate the short-circuit ratio deficit for each apportionment object. The short-circuit ratio deficit is the difference between the critical short-circuit ratio and the actual short-circuit ratio. The cost allocation ratio calculation module is used to take the proportion of the short-circuit ratio deficit of each allocation object to the total short-circuit ratio deficit of all allocation objects as the cost allocation ratio of each allocation object;
[0019] The cost allocation module is used to determine the cost to be borne by each allocated object based on the cost allocation ratio of each allocated object and the total cost of the centralized configuration network SVG.
[0020] The present invention also provides a computer-readable storage medium corresponding to the above method, wherein a computer program is stored thereon, which, when executed by a processor, implements the calculation steps of the amortization method.
[0021] The beneficial effects of this invention are as follows: 1) The allocation basis is directly derived from the objective electrical quantity of short-circuit ratio deficit, which has a clear physical meaning and can truly reflect the urgency of each station's need for reactive power support; 2) All calculations are based on electromechanical transient programs and dedicated short-circuit ratio calculation modules commonly used by power grid operators, ensuring data traceability and algorithm transparency, effectively reducing technical disputes among parties; 3) The method supports variations such as absolute deficit, relative deficit, and multiple infeed short-circuit ratios, which can flexibly cope with different assessment standards and station interaction scenarios, and has a wide range of applications; 4) It provides a scientific commercial solution for cost sharing in centralized reactive power compensation projects, which is conducive to promoting the large-scale application of grid-type SVG in new energy gathering areas. Attached Figure Description
[0022] Figure 1 This is a flowchart illustrating the economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to the present invention. Detailed Implementation
[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0024] like Figure 1 As shown, this embodiment provides an economical cost-sharing method for centralized configuration of SVG (Static Var Generator) in a renewable energy collection station network, applicable to transmission systems comprising one 500kV collection station and multiple renewable energy power plants. Each power plant connects to the 500kV busbar via its own step-up transformer, and a single grid-type SVG is centrally installed at the 500kV busbar. The cost-sharing steps are as follows: S1. Determine the assessment criteria and threshold values.
[0025] This embodiment stipulates that all substations uniformly adopt the grid connection point (outside the high-voltage side circuit breaker of the substation's step-up transformer) as the short-circuit ratio assessment point, and the critical short-circuit ratio (SCRcrit) is taken as 2.0. The rated power P of each substation is obtained. N,i .
[0026] S2. Calculate the actual short-circuit ratio based on the electromechanical transient program.
[0027] In the PSD-BPA software, establish a calculation model including the equivalent upstream power grid, 500kV bus, transformers at each substation, and equivalent generating units. Use the software's built-in short-circuit current calculation function or a dedicated MRSCR calculation module to perform a three-phase short-circuit scan. The program outputs the short-circuit capacity (SSC) at each substation's grid connection point. i The actual short-circuit ratio is calculated using the following formula: SCR meas,i =SSC i / P N,i
[0028] If a multi-infeed short-circuit ratio module is used, the MRSCR value of each station is directly read as the MRSCR. meas,i
[0029] S3. Determine the apportionment targets and deficits. Screen stations with MRSCRmeas,i < 2.0. For example, stations A, B, and C have measured values of 1.2, 1.5, and 1.8 respectively, with deficits of 0.8, 0.5, and 0.2 respectively. Station D has a measured value of 2.1 and is not included in the apportionment.
[0030] S4. Calculate the apportionment ratio.
[0031] Total shortfall = 0.8 + 0.5 + 0.2 = 1.5.
[0032] The cost-sharing ratio for station A is kA = 0.8 / 1.5 ≈ 53.33%.
[0033] The cost-sharing ratio for station B is kB = 0.5 / 1.5 ≈ 33.33%;
[0034] The cost-sharing ratio for station C is kC = 0.2 / 1.5 ≈ 13.33%.
[0035] S5. Cost Calculation.
[0036] If the total cost of building the SVG network is Ctotal = 60 million yuan, then A will bear 60 million × 53.33% ≈ 32 million yuan, B will bear 20 million yuan, and C will bear 8 million yuan (rounding illustration).
[0037] In another embodiment, if some station assessment points are taken on the low-pressure side and the critical value is 1.5, then a relative deficit calculation can be used. All deficits are uniformly converted into a proportion of the relative critical value, and then allocated according to this proportion to ensure comparability between different benchmarks.
[0038] The entire scheme can be implemented by an energy management system or a standalone computing platform. After reading the power grid model and parameters, it automatically completes short-circuit ratio scanning, deficit calculation, and proportional output. The allocation results, along with the SVG capacity determination method, are written into a shared allocation protocol for all power plants.
[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An economic allocation method for network configuration of a new energy collection station, characterized in that, Includes the following steps: Obtain the rated power of each new energy power station, and determine the assessment point of the short-circuit ratio of each station and the corresponding critical short-circuit ratio value; A regional power grid model including the collection station bus and each new energy power station is established in the electromechanical transient simulation program. The actual short-circuit ratio of each power station at the assessment point is calculated and output using the dedicated short-circuit ratio calculation module built into the electromechanical transient simulation program. Stations with actual short-circuit ratios lower than the corresponding critical short-circuit ratios are selected as apportionment targets, and the short-circuit ratio deficit for each apportionment target is calculated. The short-circuit ratio deficit is the difference between the critical short-circuit ratio and the actual short-circuit ratio. The proportion of each apportionment object's short-circuit ratio deficit to the total short-circuit ratio deficit of all apportionment objects is taken as the cost apportionment ratio of each apportionment object; Based on the cost allocation ratio of each allocated object and the total cost of centrally configuring the SVG network, the expenses to be borne by each allocated object are determined.
2. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1, characterized in that: The electromechanical transient simulation program is PSD-BPA or PSASP, and the dedicated short-circuit ratio calculation module is a short-circuit current calculation module embedded in the program or a multi-feed short-circuit ratio calculation module.
3. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1 or 2, characterized in that: The actual short-circuit ratio is the ratio of the system short-circuit capacity calculated at the assessment point to the rated power of the station.
4. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 3, characterized in that: The actual short-circuit ratio is the multi-infeed short-circuit ratio (MRSCR) output by the electromechanical transient simulation program, which reflects the electrical interaction between various stations.
5. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1, characterized in that: The assessment point is taken as the grid connection point on the high-voltage side of the step-up transformer at each station, with a corresponding critical short-circuit ratio of 2.0; or the assessment point is taken as the low-voltage side of the step-up transformer at each station, with a corresponding critical short-circuit ratio of 1.
5.
6. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1, characterized in that: When different stations use different critical short-circuit ratio values, the short-circuit ratio deficit is calculated using a relative deficit. The relative deficit is the difference between the critical short-circuit ratio and the actual short-circuit ratio, divided by the critical short-circuit ratio. The cost allocation ratio is the proportion of the relative deficit of each allocation object to the total relative deficit of all allocation objects.
7. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1, characterized in that: When a new energy power station is connected to the busbar of the collection station or when the regional power grid structure changes, the actual short-circuit ratio and subsequent steps in the electromechanical transient simulation program are re-executed to dynamically adjust the cost allocation ratio of each allocation object.
8. The economical cost-sharing method for centralized configuration of SVG in a new energy collection station network according to claim 1, characterized in that: The total cost of the centralized configuration network SVG includes the cost of the network SVG equipment, the cost of the step-up transformer and power distribution equipment, the cost of civil engineering and installation, and the cost of commissioning and grid connection testing. The cost to be borne by each of the apportionment objects = cost sharing ratio × total cost of centralized configuration of SVG network.
9. An economical cost-sharing system for centralized configuration of SVG in a new energy collection station network, used to implement the method described in any one of claims 1-8, characterized in that, include: The parameter configuration module is used to obtain the rated power of each new energy power station and determine the assessment point of the short-circuit ratio of each power station and the corresponding critical short-circuit ratio value. The short-circuit ratio calculation module is used to establish a regional power grid model including the collection station bus and each new energy power station in the electromechanical transient simulation program. Using the dedicated short-circuit ratio calculation module built into the electromechanical transient simulation program, the module calculates and outputs the actual short-circuit ratio of each power station at the assessment point. The apportionment object screening module is used to screen out the stations whose actual short-circuit ratio is lower than the corresponding critical short-circuit ratio as apportionment objects, and calculate the short-circuit ratio deficit for each apportionment object. The short-circuit ratio deficit is the difference between the critical short-circuit ratio and the actual short-circuit ratio. The cost allocation ratio calculation module is used to take the proportion of the short-circuit ratio deficit of each allocation object to the total short-circuit ratio deficit of all allocation objects as the cost allocation ratio of each allocation object; The cost allocation module is used to determine the cost to be borne by each allocated object based on the cost allocation ratio of each allocated object and the total cost of the centralized configuration network SVG.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program performs the calculation steps in the economic allocation method as described in any one of claims 1 to 8.