Aggregation equivalent modeling method for new energy pooling stations containing different types and models of cross-multistage transformers, storage medium and equipment
By using the loss equality method to perform equivalent modeling of the generator terminals and station transformers of the new energy collection station, the error and complexity problems of the equivalent model under multiple transformer levels are solved, and high-precision equivalent modeling of the new energy collection station is achieved.
Patent Information
- Application Number
- CN202511722275.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-13
AI Technical Summary
Existing modeling methods for new energy collection stations suffer from high computational complexity, large errors, and low accuracy when dealing with multi-level transformers of different types and models, making it difficult to achieve good universality in engineering practice.
The loss equivalence method is used to perform equivalent evaluation of the generator terminals and station transformers of the new energy collection station. The current and impedance are obtained by calculating the apparent power and voltage. Combined with the transformation ratio equivalence, an accurate equivalent model is established.
The accuracy of the equivalent model of the new energy collection station has been improved, the error problem under multi-level transformers has been solved, and efficient equivalent simulation analysis has been achieved.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of new energy gathering station modeling, and relates to a new energy gathering station aggregation equivalent modeling method containing different types and models, a storage medium and equipment. BACKGROUND
[0002] Due to the large number of wind farms and photovoltaic power stations in the new energy gathering station, and the presence of different types and models of stations, if each station is to be individually equivalent, the corresponding model of each transformer is to be established, and the internal complex collection network is to be established according to the actual connection, which will greatly increase the scale and complexity of simulation calculation, seriously affecting the effectiveness and real-time performance of simulation analysis, and even causing the problem of "dimension disaster". Therefore, it is necessary to establish an equivalent model of the new energy gathering station, which can ensure the accuracy of the model and improve the efficiency of the simulation. The existing equivalent modeling methods of new energy stations mainly include multi-machine equivalent method and single-machine equivalent method. The single-machine equivalent method does not need to group the new energy cluster, and although this method has small calculation amount, it ignores the differences in operating state between the units, and often has low equivalent accuracy. The multi-machine equivalent method can improve the equivalent accuracy of the model, but the existing multi-machine equivalent method needs to separately equivalent different types and models of new energy stations, and then group them according to different operating states, which will cause problems such as too many equivalent machines, complex calculation process, and poor generality in engineering practice. In order to accurately represent the external characteristics of the new energy station, the electrical parameters and mechanical parameters of the equivalent wind turbine need to be accurately calculated. At present, the capacity weighting method is generally used to calculate the transformer parameters. This calculation method will produce a large error under large-scale new energy gathering stations due to the presence of multi-stage transformers, and lacks consideration of the transformer ratio problem. Therefore, a new energy gathering station aggregation equivalent modeling method containing different types and models is needed to realize efficient analysis and equivalent of the new energy gathering station. SUMMARY
[0003] In order to solve the problem that the capacity weighting method will produce a large error due to the presence of multi-stage transformers in the equivalent modeling of the new energy gathering station.
[0004] A new energy gathering station aggregation equivalent modeling method containing different types and models of multi-stage transformers, comprising: equivalent the machine end transformer of each station to a first stage transformer T1, and equivalent the station transformer to a second stage transformer T2, and equivalent based on the loss equality method.
[0005] Further, in the process of equivalent the machine end transformer of each station to the first stage transformer T1, the current on the I side of the first stage transformer and the equivalent impedance are calculated according to the following formula:
[0006] ,
[0007] ,
[0008] wherein, is the apparent power of the I side of the ith machine-end transformer; is the voltage of the I side of the ith machine-end transformer; is the current of the I side of the ith machine-end transformer; is the current of the I side of the equivalent primary transformer; is the impedance of the ith machine-end transformer; is the equivalent impedance of the first-stage transformer; and n is the number of all stations in the new energy collection station.
[0009] Further, in the process of equivalencing the station transformer to the second-stage transformer T2, the current of the I side of the second-stage transformer and the equivalent impedance are calculated according to the following formula:
[0010] ,
[0011] ,
[0012] wherein, is the apparent power of the I side of the ith station transformer; is the voltage of the I side of the ith station transformer; is the current of the I side of the ith station transformer; is the current of the I side of the equivalent secondary transformer; is the impedance of the ith station transformer; is the equivalent impedance of the second-stage transformer; and n is the number of all stations in the new energy collection station.
[0013] Further, the transformation ratio of the transformer is equivalent to:
[0014] ,
[0015] wherein, is the equivalent current of the high-voltage side of the second-stage transformer, and the calculation method is shown in the following formula: is the equivalent transformation ratio of the first-stage transformer; is the equivalent transformation ratio of the second-stage transformer.
[0016] Further, the new energy collection station aggregation equivalent modeling method containing different types and models across multi-stage transformers further comprises: the equivalent current of the high-voltage side of the second-stage transformer is: , is the apparent power of the power collection network of the ith station in the new energy collection station; is the port voltage of the ith station in the new energy collection station. is the current of the power collection network of the i-th station in the new energy collection station; n is the number of all stations in the new energy collection station.
[0017] Further, the equivalent modeling method for the new energy collection station with different types and models across multi-level transformers further comprises that the equivalent voltage of the high-voltage side bus of the second-level transformer is .
[0018] Further, the equivalent modeling method for the new energy collection station with different types and models across multi-level transformers further comprises that the equivalent impedance of the power collection network is , is the grid-connected point voltage of the new energy collection station.
[0019] Further, the equivalent modeling method for the new energy collection station with different types and models across multi-level transformers further comprises that the rated capacity and rated power of the equivalent machine are equivalent by summing the rated power and rated capacity of each station.
[0020] A computer storage medium, characterized in that the storage medium stores at least one instruction, the at least one instruction is loaded and executed by a processor to realize the equivalent modeling method for the new energy collection station with different types and models across multi-level transformers.
[0021] An equivalent modeling device for a new energy collection station with different types and models across multi-level transformers, the device comprising a processor and a memory, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor to realize the equivalent modeling method for the new energy collection station with different types and models across multi-level transformers.
[0022] Advantages:
[0023] The present application can realize equivalent modeling for new energy stations of different types and models, and solve the problem of lack of equivalent simulation models suitable for the whole process before and after fault ride-through. In addition, through the study on the characteristics of the new energy collection station across multi-level transformers, it is found that using the capacity weighting method to calculate the equivalent parameters of the transformer will produce a large error. In order to improve the error influence of the transformer equivalent, the present application uses the loss equalization method to calculate the equivalent impedance of the transformer, which can effectively improve the precision of the equivalent model of the new energy collection station in actual application. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 is an error diagram of the existing single machine equivalent method;
[0025] Figure 2 is a topology diagram of the new energy collection station;
[0026] Figure 3 This is an equivalent diagram of the improved single-machine setup before the fault occurred. Detailed Implementation
[0027] To address the current shortcomings in equivalent modeling of renewable energy collection stations, such as the lack of consideration for multi-stage transformers of different types and models, and the insufficient in-depth consideration of equivalent parameter calculation methods for multi-stage transformers, resulting in relatively low accuracy of equivalent models in such scenarios, which fail to fully reflect their complex electrical characteristics and operational behavior, directly applying existing single-unit equivalent methods will lead to significant deviations. Figure 1 As shown in the figure. Therefore, this invention proposes an aggregated equivalent modeling method for multi-level transformer new energy collection stations containing different types and models. The topology diagram of the new energy collection station is shown in the figure. Figure 2 As shown, equivalent parameters of the generator, transformer, and power collection network are calculated separately to establish a high-precision equivalent model for a new energy aggregation station. In the process of equipping the generator-end transformers of each station with the first-stage transformer T1, the current on the I-side of the generator-end transformer is obtained based on the apparent power and voltage on the I-side of the i-th generator-end transformer, thus equipping the current on the I-side of the first-stage transformer, and subsequently equipping the corresponding impedance. Similarly, in the process of equipping the station transformers with the second-stage transformer T2, the current on the I-side of the station transformer is obtained based on the apparent power and voltage on the I-side of the station transformer, thus equipping the current on the I-side of the second-stage transformer, and subsequently equipping the corresponding impedance. The transformer turns ratio is obtained based on the equivalent currents on the I-sides of the first and second-stage transformers and the equivalent currents on the I-side and high-voltage side of the second-stage transformer. A case study of a new energy aggregation station in western Jilin Province verifies the effectiveness of the proposed method, showing that the equivalent model can well characterize the response of the detailed model under different scenarios. The following detailed implementation further illustrates the invention. Detailed Implementation
[0028] This implementation method is an aggregated equivalent modeling method for multi-level transformer new energy collection stations containing different types and models, including the following steps:
[0029] Step 1: For new energy power plants, the rated capacity and rated power are equalized by summing them up.
[0030] To provide a clear understanding of the calculation process, this implementation method uses a doubly-fed wind power cluster as an example, with appended... Figure 3 The diagram shown is an improved single-machine equivalent diagram. First, the parameters of the equivalent machine are calculated.
[0031]
[0032] In the formula, n represents the total number of stations in the new energy collection station; The rated capacity (MVA) of a single station; The rated power (MW) of a single station, The rated capacity of the equivalent machine, The rated power of the equivalent machine.
[0033] Here, the double-fed wind power cluster is taken as an example for equivalent modeling, and the equivalent method of other new energy types is the same.
[0034] Step two, since the new energy collection station crosses multiple levels of transformers, using the capacity weighting method to calculate the transformer equivalent parameters will produce a large error. In order to improve the error influence of transformer equivalent, the loss equalization method is used to calculate the transformer equivalent impedance, as shown in the accompanying Figure 3 The machine terminal transformer of each station is equivalent to the first level transformer T1, and the station transformer is equivalent to the second level transformer T2.
[0035] The specific calculation method of the current and equivalent impedance on the I side of the first level transformer is as follows:
[0036]
[0037]
[0038] In the formula, The apparent power on the I side of the i-th machine terminal transformer; The voltage on the I side of the i-th machine terminal transformer; The current on the I side of the i-th machine terminal transformer; The current on the I side of the equivalent first level transformer; The impedance of the i-th machine terminal transformer; The equivalent impedance of the first level transformer.
[0039] The calculation method of the current and equivalent impedance on the I side of the second level transformer is the same as that of the first level, and the specific calculation formula is as follows:
[0040]
[0041]
[0042] In the formula, The apparent power on the I side of the i-th station transformer; The voltage on the I side of the i-th station transformer; The current on the I side of the i-th station transformer; The current on the I side of the equivalent second level transformer; The impedance of the i-th station transformer; The equivalent impedance of the second level transformer.
[0043] In addition, the transformer turns ratio also affects the accuracy of the equivalent model. Therefore, based on the relationship between turns ratio and current, the calculation method for the equivalent transformer turns ratio (i.e., the transformer's equivalent turns ratio) is as follows:
[0044]
[0045] In the formula, The equivalent current on the high-voltage side of the second-stage transformer is calculated using the following formula; This refers to the equivalent turns ratio of the first-stage transformer. This is the equivalent turns ratio of the second-stage transformer.
[0046] Step 3: The main calculation content of the equivalent parameters of the collector network is the equivalent impedance of the equivalent line. Following the principle that the power and current injected into the nodes are equal before and after equivalence, as shown in the attached diagram... Figure 3 The calculations shown indicate that the equivalent current on the high-voltage side of the second-stage transformer is:
[0047]
[0048] In the formula, Let be the apparent power of the power collection network of the i-th power station in the new energy collection station; Let be the port voltage of the i-th station in the new energy collection station; Let be the current in the current collector network of the i-th power station in the new energy collection station.
[0049] The equivalent voltage of the high-voltage side busbar of the second-stage transformer is:
[0050]
[0051] The equivalent impedance of the collector network is:
[0052]
[0053] In the formula, The voltage at the grid connection point of the new energy collection station.
[0054] At this point, the calculation of key parameters for the improved single-unit equivalent model is complete, realizing the calculation of aggregated equivalent parameters for new energy collection stations spanning multiple transformer levels.
[0055] Example
[0056] Taking a certain new energy collection station as an example for verification, an aggregated equivalent model was established in the PSASP software, and the equivalent model parameters were calculated according to the improved aggregated equivalent method described above.
[0057] The adaptability of the equivalent model for the new energy collection station in two output scenarios—high power range (active power P range of 0.7pu≤P≤0.9pu) and low power range (active power P range of 0.2pu≤P≤0.4pu)—was verified. Tables 1 and 2 show the comparison of active and reactive power equivalent results between the traditional and improved equivalent models in the high power and low power ranges, respectively.
[0058] Table 1 Comparison of equivalent results in the high power range
[0059]
[0060] Table 2 Comparison of equivalent results in the low power range
[0061]
[0062] As can be seen from the table, under different output scenarios, the improved single-machine equivalent model has significantly improved the equivalent accuracy compared to the traditional single-machine equivalent model, proving that the method has good adaptability to the output scenarios of new energy collection stations.
[0063] In summary, this invention proposes an improved aggregation equivalence method for new energy collection stations of different types and models, achieving efficient analytical equivalence of new energy collection stations. Specific Implementation Method Two:
[0065] This embodiment is a computer storage medium that stores at least one instruction. The at least one instruction is loaded and executed by a processor to implement the above-described method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models.
[0066] It should be understood that the instructions include computer program products, software, or computerized methods corresponding to any method described in this invention; the instructions can be used to program computer systems or other electronic devices. Computer storage media may include readable media on which instructions are stored, and may include, but are not limited to, magnetic storage media, optical storage media; magneto-optical storage media include read-only memory (ROM), random access memory (RAM), erasable programmable memory (e.g., EPROM and EEPROM), and flash memory layers, or other types of media suitable for storing electronic instructions. Specific implementation method three:
[0068] This embodiment is a multi-level transformer new energy collection station aggregation equivalent modeling device with different types and models. The device includes a processor and a memory. It should be understood that it includes any device with a processor and a memory described in this invention. The device may also include other units and modules that perform display, interaction, processing, control and other functions through signals or instructions.
[0069] The memory stores at least one instruction, which is loaded and executed by the processor to implement the above-mentioned method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models.
[0070] Those skilled in the art will understand that at least one stored instruction constitutes a computer program product corresponding to a method or system. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can 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-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.
[0071] This application is described with reference to flowchart illustrations and / or block diagrams of methods, systems, and computer program products according to embodiments of this application, and can also be used with corresponding devices. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations 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, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0072] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0073] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0074] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0075] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
[0076] It should be noted that the specific embodiments are merely explanations and illustrations of the technical solution of the present invention and should not be used to limit the scope of protection. Any modifications made in accordance with the claims and specification of the present invention that are only partial should still fall within the protection scope of the present invention.
Claims
1. A method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models, characterized in that, include: The generator terminal transformers of each station are equivalent to the first-level transformer T1, and the station transformers are equivalent to the second-level transformer T2, based on the principle of equal losses.
2. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 1, characterized in that, In the process of equipping the generator terminal transformers of each station with the first-stage transformer T1, the specific calculation method for the current and equivalent impedance on the I side of the first-stage transformer is as follows: ， ， In the formula, Let be the apparent power on side I of the i-th terminal transformer; Let be the voltage on side I of the i-th terminal transformer; Let I be the current on the I-th terminal transformer. This is the current on the I side of the equivalent primary transformer; Let be the impedance of the i-th terminal transformer; is the equivalent impedance of the first-stage transformer; n is the number of all stations in the new energy collection station.
3. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 2, characterized in that, The specific calculation methods for the current and equivalent impedance on the I side of the second-stage transformer are as follows: (The original text contains some formatting errors and inconsistencies. A more accurate translation would require the full context.) ， ， In the formula, Let be the apparent power on the I-side of the transformer at the i-th substation; Let be the voltage on side I of the transformer at the i-th substation; Let I be the current on the I-th transformer of the i-th substation; This represents the current on side I of the equivalent secondary transformer; Let be the impedance of the i-th substation transformer; is the equivalent impedance of the second-stage transformer; n is the number of all stations in the new energy collection station.
4. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 3, characterized in that, The transformer turns ratio is equal to: ， In the formula, The equivalent current on the high-voltage side of the second-stage transformer is calculated using the following formula; This refers to the equivalent turns ratio of the first-stage transformer. This is the equivalent turns ratio of the second-stage transformer.
5. A method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models, as described in any one of claims 1 to 4, characterized in that... This also includes: setting the equivalent current on the high-voltage side of the second-stage transformer as: , Let be the apparent power of the power collection network of the i-th power station in the new energy collection station; Let be the port voltage of the i-th station in the new energy collection station; Let be the current in the power collection network of the i-th station in the new energy collection station; n is the number of all stations in the new energy collection station.
6. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 5, characterized in that, Also includes: The equivalent voltage of the high-voltage busbar of the second-stage transformer is .
7. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 6, characterized in that, Also includes: The equivalent impedance of the collector network is , The voltage at the grid connection point of the new energy collection station.
8. The method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in claim 7, characterized in that, Also includes: The rated capacity and rated power of the equivalent machine are calculated by summing the rated power and rated capacity of each station.
9. A computer storage medium, characterized in that, The storage medium stores at least one instruction, which is loaded and executed by a processor to implement the method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in any one of claims 1 to 8.
10. A device for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models, characterized in that, The device includes a processor and a memory, wherein the memory stores at least one instruction, which is loaded and executed by the processor to implement the method for aggregated equivalent modeling of multi-level transformer new energy collection stations containing different types and models as described in any one of claims 1 to 8.