Equivalent circuit optimization design method and device for high-voltage transmission line

Abstract

The invention discloses an equivalent circuit optimization design method and device of a high-voltage power transmission line, which are used for solving the problem of how to accurately characterize complex distribution parameter line characteristics by using a lumped parameter equivalent circuit and maintain the simplicity of a mathematical form in the actual engineering calculation of the high-voltage power transmission line. The method comprises the following steps: acquiring initial line parameters of a high-voltage transmission line, and constructing a real impedance curve according to the initial line parameters; obtaining an initial configuration parameter set of an equivalent circuit of the high-voltage transmission line, and calculating a plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set; an equivalent impedance curve of each equivalent line impedance is generated, error comparison is carried out according to the real impedance curve and the plurality of equivalent impedance curves, and the optimal equivalent line impedance is determined; and outputting a configuration parameter corresponding to the optimal equivalent line impedance as an equivalent circuit optimal configuration parameter of the high-voltage transmission line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-voltage transmission system design, and particularly relates to an equivalent circuit optimization design method of a high-voltage transmission line, an equivalent circuit optimization design device of a high-voltage transmission line, an electronic device and a storage medium. BACKGROUND

[0002] In a power system, a high-voltage transmission line undertakes a key task of transmitting electric energy across regions and over long distances. Accurate electrical parameters of the high-voltage transmission line are the core basis for power system load flow calculation, transient stability analysis, fault location, relay protection setting, and system planning design and operation control. The accuracy of the line parameters is directly related to the effectiveness of the mathematical model of the power grid, and further affects the safety, stability and economy of system operation. Therefore, accurate extraction and equivalent modeling of the parameters of the high-voltage transmission line have always been an important issue in power system analysis and calculation.

[0003] The electrical parameters (resistance, inductance and capacitance) of the high-voltage transmission line are essentially uniformly distributed along the entire length of the line, and are therefore referred to as distributed parameters. In traditional power system analysis, different equivalent models are used for different lengths of lines and different analysis purposes. For short lines, the distributed characteristics can usually be ignored, and a simple lumped parameter pi-type or T-type equivalent circuit is used. However, for long-distance, high-voltage transmission lines, the distributed parameter effect becomes very significant. At this time, a distributed parameter model must be used for description in order to accurately reflect the electrical characteristics. Although the distributed parameter model is most accurate in physical description, it is extremely complex in mathematical processing. Direct application of the distributed parameter model to analytical mathematical modeling such as load flow calculation and stability analysis of large-scale power grids will dramatically increase the amount of calculation and make equation solving extremely difficult, severely restricting the efficiency and refinement of system analysis.

[0004] Therefore, in the actual engineering calculation of the high-voltage transmission line, how to accurately characterize the complex distributed parameter line characteristics with a lumped parameter equivalent circuit while maintaining the simplicity of the mathematical form is an important problem that needs to be solved. SUMMARY

[0005] The present application provides an equivalent circuit optimization design method of a high-voltage transmission line, an equivalent circuit optimization design device of a high-voltage transmission line, an electronic device and a storage medium, which are used to solve or partially solve the problem of how to accurately characterize the complex distributed parameter line characteristics with a lumped parameter equivalent circuit while maintaining the simplicity of the mathematical form in the actual engineering calculation of the high-voltage transmission line.

[0006] The present application provides an equivalent circuit optimization design method of a high-voltage transmission line, comprising:

[0007] Obtaining initial line parameters of a high-voltage transmission line, and constructing a real impedance curve according to the initial line parameters;

[0008] Obtaining an initial configuration parameter set of an equivalent circuit of the high-voltage transmission line, and calculating a plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set;

[0009] Generating an equivalent impedance curve of each of the equivalent line impedances respectively, and determining an optimal equivalent line impedance according to error comparison between the real impedance curve and a plurality of the equivalent impedance curves;

[0010] Outputting a configuration parameter corresponding to the optimal equivalent line impedance as an optimal configuration parameter of the equivalent circuit of the high-voltage transmission line.

[0011] Optionally, the equivalent circuit of the high-voltage transmission line is composed of a plurality of π-type circuits and a plurality of auxiliary circuits in series; the initial configuration parameter set includes initial configuration parameters of the plurality of π-type circuits and the plurality of auxiliary circuits under different parameter configurations; and the calculating of the plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set includes:

[0012] For each of the initial configuration parameters, calculating a line end impedance of the equivalent circuit based on the initial configuration parameter;

[0013] Arranging the plurality of π-type circuits in a connection order from the line end impedance to a last π-type circuit, and calculating a parallel superposition impedance from the line end impedance to the last π-type circuit by using a one-by-one parallel superposition calculation mode;

[0014] Arranging the plurality of auxiliary circuits in a connection order from the parallel superposition impedance to a last auxiliary circuit, and calculating a series superposition impedance from the parallel superposition impedance to the last auxiliary circuit by using a one-by-one series superposition calculation mode, as the equivalent line impedance under the initial configuration parameter;

[0015] Integrating the equivalent line impedances corresponding to each of the initial configuration parameters as the plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0016] Optionally, the determining of the optimal equivalent line impedance according to the error comparison between the real impedance curve and a plurality of the equivalent impedance curves includes:

[0017] For each of the equivalent impedance curves, calculating an error between the equivalent impedance curve and the real impedance curve;

[0018] The equivalent line impedance corresponding to the equivalent impedance curve with the smallest error and that meets the preset error conditions is taken as the optimal equivalent line impedance.

[0019] Optionally, the method further includes:

[0020] If the minimum error still cannot meet the preset error condition, a new set of initial configuration parameters after adjustment is obtained, and the equivalent line impedance is recalculated based on the new set of initial configuration parameters.

[0021] Optionally, the equivalent circuit of the high-voltage transmission line is composed of several π-type circuits and several auxiliary circuits connected in series; the method further includes:

[0022] When the scale of the π-type circuit and auxiliary circuit in the equivalent circuit of the high-voltage transmission line is greater than or equal to a preset scale condition, the initial configuration parameter set is optimized by a genetic evolution algorithm to obtain the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0023] Optionally, the process of optimizing the initial configuration parameter set using a genetic evolution algorithm includes:

[0024] Step S1: Initialize a population based on the initial configuration parameter set, and determine the dimension and value boundary of the initial configuration parameter set during optimization iteration based on the initial line parameters. Determine the population mutation scale based on the degree of influence of each parameter variable in the initial configuration parameter set on the line impedance.

[0025] Step S2: Perform population mutation on the pre-mutation population at the specified population mutation scale to obtain the post-mutation population;

[0026] Step S3: According to the preset population crossover ratio, randomly select new samples from the mutated population to replace the old samples in the pre-mutated population to obtain a mutated crossover population; the mutated crossover population corresponds to the optimized configuration parameter set;

[0027] Step S4: Based on the optimized configuration parameter set and the actual impedance curve, construct the error matrix;

[0028] Step S5: Select multiple target errors from the error matrix based on preset error screening conditions, and select the optimal population from the mutated crossover population according to the multiple target errors;

[0029] Step S6: Determine whether the iteration termination condition is met. If not, use the optimal population as the pre-mutation population for the next iteration and proceed to step S2. If yes, determine the configuration parameter corresponding to the minimum error from the optimal population and use it as the optimal configuration parameter for the equivalent circuit of the high-voltage transmission line.

[0030] Optionally, the initial line parameters include the key line parameters and line connection forms of the high-voltage transmission line; the step of constructing the true impedance curve based on the initial line parameters includes:

[0031] Based on the key line parameters and the line connection form, an electromagnetic transient model of the high-voltage transmission line is constructed through electromagnetic transient simulation.

[0032] Based on the electromagnetic transient model of the line, the true impedance curve of the high-voltage transmission line is obtained by frequency scanning.

[0033] The present invention also provides an equivalent circuit optimization design device for high-voltage transmission lines, comprising:

[0034] The real impedance curve construction unit is used to obtain the initial line parameters of the high-voltage transmission line and construct the real impedance curve based on the initial line parameters.

[0035] An equivalent line impedance calculation unit is used to obtain the initial configuration parameter set of the equivalent circuit of the high-voltage transmission line, and to calculate multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0036] The optimal equivalent line impedance determination unit is used to generate the equivalent impedance curves of each of the equivalent line impedances, and to determine the optimal equivalent line impedance by comparing the error between the actual impedance curve and multiple equivalent impedance curves.

[0037] The optimal configuration parameter output unit is used to output the configuration parameters corresponding to the optimal equivalent line impedance, as the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0038] The present invention also provides an electronic device, the device comprising a processor and a memory:

[0039] The memory is used to store program code and transmit the program code to the processor;

[0040] The processor is used to execute the equivalent circuit optimization design method for high-voltage transmission lines as described above, according to the instructions in the program code.

[0041] The present invention also provides a computer-readable storage medium for storing program code for executing the equivalent circuit optimization design method for high-voltage transmission lines as described in any of the preceding claims.

[0042] As can be seen from the above technical solutions, the present invention has the following advantages:

[0043] This invention provides a method for optimizing the equivalent circuit design of high-voltage transmission lines. First, a true impedance curve is constructed based on the initial line parameters of the high-voltage transmission line. Then, an initial configuration parameter set for the equivalent circuit of the high-voltage transmission line is obtained, and multiple equivalent line impedances under the initial configuration parameter set are calculated. Next, equivalent impedance curves for each equivalent line impedance are generated, and the error is compared with the true impedance curves to determine the optimal equivalent line impedance. Finally, the configuration parameters corresponding to the optimal equivalent line impedance are output as the optimal configuration parameters for the equivalent circuit of the high-voltage transmission line. By employing the technical solution provided by this invention, the accuracy of equivalent modeling of high-voltage transmission lines is improved, especially the impedance fitting accuracy in the low-frequency band, which is significantly improved compared to traditional π-type circuits. This provides a more accurate and simpler equivalent transmission circuit model for power system modeling and calculation, improving the accuracy and efficiency of power system calculation and analysis. On the other hand, the automatic configuration of parameters for the equivalent circuit of high-voltage transmission lines proposed in this invention can be completed automatically by computer, without the need for professional electrical design experts to manually design and calculate system parameters. It can also ensure that the highest accuracy of line impedance equivalence is achieved with the fewest number of π-type circuits cascaded, saving manpower and time and greatly improving efficiency. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is an example of the impedance spectrum of a typical high-voltage transmission line;

[0046] Figure 2 This is a schematic diagram of a commonly used π-type equivalent circuit for high-voltage transmission lines;

[0047] Figure 3 This is an example diagram of the impedance curve of a π-type equivalent circuit;

[0048] Figure 4 This is a schematic diagram of a broadband high-efficiency equivalent circuit for a high-voltage transmission line provided in an embodiment of the present invention;

[0049] Figure 5 A flowchart illustrating the steps of an equivalent circuit optimization design method for high-voltage transmission lines;

[0050] Figure 6 This is a flowchart for calculating an equivalent line impedance.

[0051] Figure 7This is a flowchart illustrating a circuit parameter optimization configuration based on a genetic evolutionary algorithm.

[0052] Figure 8 An example impedance spectrum diagram of a wideband, high-efficiency equivalent circuit;

[0053] Figure 9 A schematic diagram of the overall process for an equivalent circuit optimization design method for high-voltage transmission lines;

[0054] Figure 10 This is a structural block diagram of an equivalent circuit optimization design device for high-voltage transmission lines. Detailed Implementation

[0055] This invention provides an equivalent circuit optimization design method for high-voltage transmission lines, an equivalent circuit optimization design device for high-voltage transmission lines, an electronic device, and a storage medium, which are used to solve or partially solve the problem of how to accurately characterize the complex distributed parameter line characteristics with lumped parameter equivalent circuits in the actual engineering calculations of high-voltage transmission lines, while maintaining the simplicity of the mathematical form.

[0056] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0057] As an example, the electrical parameters (resistance, inductance, and capacitance) of high-voltage transmission lines are essentially uniformly distributed along the entire length of the line, hence they are called distributed parameters. In traditional power system analysis, different equivalent models are used for lines of different lengths and for different analytical purposes. For short lines, their distributed characteristics can usually be ignored, and simple lumped-parameter π-type or T-type equivalent circuits can be used. However, for long-distance, high-voltage transmission lines, the effects of distributed parameters become very significant. In this case, a distributed parameter model must be used to accurately reflect their electrical characteristics. Although the distributed parameter model is the most accurate in physical description, it is extremely complex mathematically. Directly applying it to analytical mathematical modeling such as power flow calculations and stability analysis of large-scale power grids will drastically increase the computational load and make solving the equations exceptionally difficult, severely limiting the efficiency and precision of system analysis.

[0058] Currently, the main problems with methods for equivalent line equivalence are as follows:

[0059] The accuracy of a single π-type equivalent model is insufficient: For mathematical simplicity, a single π-type equivalent circuit is often used in engineering to approximate distributed parameter lines. While this method simplifies calculations, its accuracy decreases sharply with increasing line length and frequency. When analyzing high-frequency transient processes or for long ultra-high voltage / extra-high voltage lines, the error of a single π-type model is unacceptable and cannot meet the accuracy requirements of modern power systems.

[0060] The challenge of parameter configuration for multi-section cascaded π-type models: Theoretically, by cascading multiple π-type equivalent circuit units, the distributed parameter characteristics of the circuit can be approximated. However, traditional techniques lack an intelligent and efficient method to determine the optimal configuration of such cascaded models. Specifically, it faces three major challenges:

[0061] Determining the number of cascade series n: Too few cascade series result in insufficient approximation accuracy. Too many cascade series lead to excessive model complexity and reduced computational efficiency. There is a lack of intelligent selection criteria for balancing accuracy and complexity.

[0062] Element parameter allocation: There is a lack of scientific and effective methods for determining the values ​​of parameters such as series resistance, series reactance, and parallel capacitance in each π-type element. Current methods mostly rely on empirical formulas or simple average allocation, failing to fully utilize the global electrical characteristics of the line for optimization, resulting in poor impedance spectrum matching between the equivalent model and the real line over a wide frequency band.

[0063] Lack of automated means for global optimization: Traditional trial-and-error methods or parameter configuration methods based on simple rules are cumbersome, inefficient, and difficult to find the global optimal solution. They rely heavily on the personal experience of engineers and have poor repeatability and universality.

[0064] In summary, a significant contradiction exists in current technology: accurate distributed parameter models are not conducive to analytical mathematical modeling, while lumped parameter equivalent models, which are easier to model, suffer from insufficient accuracy or difficulties in parameter configuration. Therefore, in the practical engineering calculations of high-voltage transmission lines, how to accurately characterize the complex distributed parameter line characteristics using lumped parameter equivalent circuits while maintaining mathematical simplicity is a crucial problem that urgently needs to be solved.

[0065] Therefore, one of the core inventive points of this invention is to propose a method for intelligently, quickly, and accurately identifying and extracting lumped equivalent parameters of high-voltage transmission lines. This method can automatically generate equivalent circuits that highly match the actual characteristics of the lines over a wide frequency band, providing a solid foundation for refined mathematical modeling and efficient analysis and calculation of power systems.

[0066] For ease of understanding, the typical impedance spectrum of a high-voltage transmission line can be referenced. Figure 1This spectrum can be obtained through actual on-site measurement or through impedance scanning using electromagnetic transient simulation software.

[0067] To obtain Figure 1 The impedance curve in the image can generally be obtained using methods such as... Figure 2 The commonly used π-type equivalent circuit is shown. The principle is to approximate the distributed parameter characteristics of the line by connecting n π-type circuit units in series. However, this method still has some limitations. First, the π-type circuit differs significantly from the actual impedance of the line over a wide frequency band. Figure 3 An example diagram of the impedance curve for a π-type equivalent circuit is shown. The "*" line represents... Figure 2 The fitting results show that the error is large in the low-frequency band, leading to significant calculation errors. Furthermore, there is currently a lack of a smart and efficient method to determine the optimal configuration of this cascaded model, including the values ​​of the series stage number n, inductance L, resistance R, and capacitance C.

[0068] To address the aforementioned problems, this invention proposes a broadband, high-efficiency equivalent circuit for high-voltage transmission lines, along with its optimized design process and method. Designing the equivalent circuit of high-voltage transmission lines based on this process and method can significantly improve the accuracy and efficiency of the design.

[0069] An embodiment of the present invention provides a broadband high-efficiency equivalent circuit for high-voltage transmission lines, such as... Figure 4 As shown.

[0070] Figure 4 The broadband equivalent circuit adds m auxiliary circuits to the commonly used π-type equivalent circuit, such as... Figure 4 As shown in the red dashed box. The number of auxiliary circuits can be adjusted adaptively according to different actual circuit parameters. Generally, it can be set to around 1 to 3. Each auxiliary circuit has different parameters for capacitance Cp, inductance Lp, and resistance Rp.

[0071] It should be pointed out that, Figure 4 This is merely one example of the equivalent circuit provided in this embodiment of the invention. For ease of explanation, the auxiliary circuits are all uniformly arranged on one side of the π-type circuit. In practical applications, the auxiliary circuits can be located to the left or right of the π-type circuit, or they can be distributed or concentrated within the series-connected π-type circuit. That is, the auxiliary circuits can also be designed with spacing or dispersion, as long as the auxiliary circuits are connected in series with the π-type circuit in one loop. In addition, if higher precision requirements are needed, the π-type circuit can also be in the form of a large resistor connected in parallel next to the capacitor C. It is understood that this invention does not impose any limitations on this.

[0072] exist Figure 4 Based on the equivalent circuit of high-voltage transmission lines, and referring to Figure 5The diagram illustrates a flowchart of the equivalent circuit optimization design method for high-voltage transmission lines provided by an embodiment of the present invention, which specifically includes the following steps:

[0073] Step 501: Obtain the initial line parameters of the high-voltage transmission line, and construct the actual impedance curve based on the initial line parameters;

[0074] For technicians, the first step is to clarify the design requirements, prepare the relevant input parameters (i.e., determine the key line parameters of the high-voltage transmission line), and input them into the system to initialize the relevant parameters. This includes determining the type of transmission tower, line length, sensitive frequency range, etc.

[0075] Secondly, it is necessary to determine the connection type of the high-voltage transmission line. Specifically, this mainly involves clarifying the wiring status of the line (i.e., determining the connection type of the high-voltage transmission line). For example, whether the end of the line is grounded, open-circuited, or connected to other loads such as resistors.

[0076] For the system, the first step is to construct the true impedance curve Z of the high-voltage transmission line based on the initial line parameters. line0 (i.e., the true and accurate impedance curve Z) line0 This step involves building a detailed distributed parameter model of the high-voltage transmission line in the electromagnetic transient model and obtaining the required true impedance curve Z through frequency scanning. line0 , which serves as the impedance fitting target for the equivalent circuit.

[0077] In another alternative embodiment, if the high-voltage transmission line under study has undergone actual field impedance testing, the test data can also be used as the true impedance curve.

[0078] Based on the foregoing discussion, the initial line parameters mentioned in the embodiments of this invention mainly include the key line parameters and connection forms of the high-voltage transmission line. The implementation process for constructing the true impedance curve based on the initial line parameters specifically includes: constructing an electromagnetic transient simulation model of the high-voltage transmission line through electromagnetic transient simulation based on the key line parameters and connection forms; and obtaining the true impedance curve of the high-voltage transmission line through frequency scanning based on the electromagnetic transient simulation.

[0079] Step 502: Obtain the initial configuration parameter set of the equivalent circuit of the high-voltage transmission line, and calculate the multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0080] This step primarily involves setting the initial configuration parameters of the equivalent circuit line impedance for high-voltage transmission lines. This mainly includes... Figure 4The initial configuration parameters for the π-type circuit and auxiliary circuits include the initial parameters and their configuration ranges for the π-type circuit, such as the number of series stages n, resistance R, inductance L, and capacitance C, as well as the parameters and their configuration ranges for the auxiliary circuits, such as the number of auxiliary circuits m, Cp, Lp, and Rp. On the other hand, intelligent line impedance configuration begins based on the initial configuration parameters (i.e., calculating multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set).

[0081] In this embodiment of the invention, the intelligent configuration process for line impedance is mainly based on Figure 4 The equivalent circuit structure is determined. Based on the initial configuration parameters, the equivalent line impedance Z1 of the equivalent circuit is calculated using methods such as traversal calculation (when the equivalent circuit size is small) under different parameter configurations (i.e., when the number of auxiliary circuits m, Cp, Lp, and Rp, the number of series stages n of the π-type circuit, and the resistance R, inductance L, and capacitance C are all different values). The calculation process for the equivalent line impedance Z1 can be found in [link to relevant documentation]. Figure 6 .

[0082] Subsequently, based on the expression for the equivalent line impedance Z1, the equivalent impedance curve Z within the selected frequency range can be obtained. line1 For each equivalent impedance curve, the equivalent impedance curve Z can be... line1 Compared with the true impedance curve Z line0 To compare the two, the error Zer is calculated using the following formula:

[0083]

[0084] Where abs() represents the absolute value of the line impedance; angle() represents the phase angle of the line impedance; and Z0 represents the actual line impedance. If there are zero values ​​in the denominator, an appropriate zero-removal factor can be added to the denominator to ensure convergence of the calculation.

[0085] Within the configuration parameter range, the equivalent line impedance Z1 corresponding to the equivalent impedance curve when the error Zer is minimized is extracted as the output.

[0086] Combination Figure 4 The equivalent circuit of a high-voltage transmission line consists of several π-type circuits and several auxiliary circuits connected in series. Simultaneously, the initial configuration parameter set includes the initial configuration parameters of the several π-type circuits and several auxiliary circuits under different parameter configurations.

[0087] Combination Figure 6 The implementation process for calculating multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set mainly includes:

[0088] For each initial configuration parameter, calculate the line-end impedance X0 of the equivalent circuit based on the initial configuration parameter;

[0089] Starting from the line end impedance X0, several π-type circuits are arranged in order of connection to the line end impedance X0 from near to far. The parallel superposition calculation method is adopted to calculate the parallel superposition impedance Xbn from the line end impedance X0 to the last π-type circuit.

[0090] Starting with the parallel superimposed impedance Xbn, several auxiliary circuits are arranged in order of connection with the parallel superimposed impedance Xbn from near to far. The series superimposed impedance Ycm from the parallel superimposed impedance Xbn to the last auxiliary circuit is calculated by using the series superimposed calculation method one by one, which is used as the equivalent line impedance Z1 under the initial configuration parameters.

[0091] The equivalent line impedance Z1 corresponding to each initial configuration parameter is integrated as multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0092] It is understood that the equivalent line impedance calculation process provided in the embodiments of the present invention refers to... Figure 4 The equivalent circuit setup is shown. For equivalent circuits based on other design styles of π-type circuits and auxiliary circuits, their equivalent line impedances can be calculated using the above process. When calculating the equivalent line impedance from the end to the beginning of the equivalent line, if a π-type circuit is encountered, a parallel superposition calculation method is used to calculate the line impedance obtained from the previous line calculation combined with the π-type circuit in parallel. If an auxiliary circuit is encountered, a series superposition calculation method is used to calculate the line impedance obtained from the previous line calculation combined with the auxiliary circuit in series.

[0093] Step 503: Generate equivalent impedance curves for each of the equivalent line impedances, and compare the error between the actual impedance curve and multiple equivalent impedance curves to determine the optimal equivalent line impedance.

[0094] Next, based on the calculated equivalent line impedances, equivalent impedance curves for each equivalent line impedance are generated. The error is then compared between the actual impedance curve and each equivalent impedance curve to determine the optimal equivalent line impedance. Specifically, this step primarily determines whether the equivalent line impedance Z1 with the smallest error obtained in the previous steps meets the preset error condition requirements. Specific indicators can be determined according to actual needs. For example, the error condition requirement can be set to be met when the Zer corresponding to the smallest error Z1 is less than 10%. If the requirement is met, it is determined as the optimal equivalent line impedance, and the equivalent parameters of the high-voltage transmission line are subsequently output. If the requirement is not met, the initial configuration parameters are readjusted, and the equivalent line impedance calculation is re-executed.

[0095] Furthermore, by comparing the error between the true impedance curve and multiple equivalent impedance curves, the optimal equivalent line impedance is determined. Specifically, this may include: firstly, for each equivalent impedance curve, calculating the error between the equivalent impedance curve and the true impedance curve (mainly comparing the corresponding frequency points within the selected frequency range on the two curves); and then taking the equivalent line impedance corresponding to the equivalent impedance curve with the smallest error and that meets the preset error conditions as the optimal equivalent line impedance.

[0096] In another scenario, if the minimum error still fails to meet the preset error condition, a new set of initial configuration parameters is obtained after adjustment, and the equivalent line impedance is recalculated based on the new set of initial configuration parameters.

[0097] Step 504: Output the configuration parameters corresponding to the optimal equivalent line impedance as the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0098] Finally, the configuration parameters corresponding to the optimal equivalent line impedance can be output as the optimal configuration parameters for the equivalent circuit of the high-voltage transmission line.

[0099] In some alternative embodiments, when the number of parameters to be configured is too large, resulting in a large amount of computation, intelligent algorithms such as genetic evolution algorithms can be used to optimize the configuration of circuit parameters in order to improve efficiency.

[0100] The requirement to configure too many parameters refers to situations where the line length is long, such as hundreds of kilometers or more, and the requirements for the accuracy of line impedance calculation and frequency range are high. In such cases, it is necessary to use 10 or even dozens of π-type circuits in series, resulting in a huge amount of calculation and greatly affecting the calculation efficiency.

[0101] When the scale of the π-type circuit and auxiliary circuit in the equivalent circuit of a high-voltage transmission line is greater than or equal to the preset scale condition, the initial configuration parameter set can be optimized by using a genetic evolution algorithm to obtain the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0102] Figure 7 A flowchart illustrating a circuit parameter optimization configuration based on a genetic evolution algorithm is shown.

[0103] Combination Figure 7 The process for optimizing the initial configuration parameter set using a genetic evolution algorithm, provided in this embodiment of the invention, mainly includes steps S1 to S6:

[0104] Step S1: Initialize a population based on the initial configuration parameter set, and determine the dimension and value boundary of the initial configuration parameter set during optimization iteration based on the initial line parameters. Determine the population mutation scale based on the degree of influence of each parameter variable in the initial configuration parameter set on the line impedance.

[0105] First, parameter initialization is performed. The input parameters, including their dimension and value boundaries, are determined based on the wiring and structure of the high-voltage transmission line under study. Then, the initial population size and maximum number of iterations are determined based on the computational scale and speed. Typical input parameters include: Figure 4 The initial configuration parameters for the π-type circuit and auxiliary circuits. These include the initial parameters and ranges for the π-type circuit (number of series stages n, resistance R, inductance L, capacitance C, etc.), and the auxiliary circuits (number of auxiliary circuits m, Cp, Lp, Rp, etc.) and their ranges. For population variation, the magnitude of population variation needs to be set according to the degree of influence of each parameter variable on the impedance; that is, the population variation scale.

[0106] Step S2: Perform population mutation on the pre-mutation population at the specified population mutation scale to obtain the post-mutation population;

[0107] At the scale of population variation, implementing population variation on an old population can yield a new population after the variation.

[0108] Step S3: According to the preset population crossover ratio, randomly select new samples from the mutated population to replace the old samples in the pre-mutated population to obtain the mutated crossover population; the mutated crossover population corresponds to the optimized configuration parameter set;

[0109] Step S3 mainly involves performing the population crossover operation. An appropriate crossover ratio can be preset, and samples from the old population are randomly replaced with samples from the mutated new population according to this ratio to obtain a new mutated population. The mutated new population corresponds to the optimized configuration parameter set.

[0110] Step S4: Based on the optimized configuration parameter set and combined with the actual impedance curve, construct the error matrix;

[0111] Step S4 primarily involves calculating the target parameters (i.e., the error). Based on the new population obtained after mutation and crossover in step S3 (corresponding to the optimized configuration parameter set), through... Figure 6 The equivalent line impedance calculation process shown and the error calculation formula of the previous steps can be used to calculate the corresponding new target matrix (an error matrix composed of the errors between multiple equivalent impedance curves and the real impedance curve).

[0112] Step S5: Select multiple target errors from the error matrix based on preset error screening conditions, and select the optimal population from the mutated crossover population based on the multiple target errors;

[0113] Step S5 primarily involves population selection. Based on the requirements of the target parameters, the new population after mutation and crossover is selected to obtain the optimal population. For example, 50% of the errors are selected from the error matrix in ascending order of error Zer (e.g., 50 errors arranged in ascending order of error value from 100 errors in the error matrix). Furthermore, based on these errors, the top 50% of the new population after mutation and crossover (50 individuals corresponding to the selected 50 errors) are selected as the optimal population after this iteration.

[0114] Step S6: Determine whether the iteration termination condition is met. If not, use the optimal population as the pre-mutation population for the next iteration and jump to step S2. If yes, determine the configuration parameters corresponding to the minimum error from the optimal population and use them as the optimal configuration parameters for the equivalent circuit of the high-voltage transmission line.

[0115] Determine if the iteration termination condition is met, such as whether the maximum number of iterations has been reached or whether the error Zer is less than the engineering allowable error, such as 5%. If the condition is met, end the iteration and output the optimal equivalent line parameter configuration result. If not, use the optimal population as the pre-mutation population for the next iteration and proceed to step S2.

[0116] The technical solutions provided by the embodiments of the present invention... Figure 4 By configuring the parameters of the equivalent circuit, the impedance spectrum of the broadband, high-efficiency equivalent circuit can be obtained, as shown below. Figure 8 As shown. It can be seen that, compared to Figure 3 The equivalent impedance spectrum is shown below. Figure 8 The accuracy of the equivalent impedance spectrum shown has been significantly improved.

[0117] In this embodiment of the invention, an optimized design method for the equivalent circuit of a high-voltage transmission line is provided based on the improvement of the equivalent circuit using auxiliary circuits. First, the initial line parameters of the high-voltage transmission line are determined, and a true impedance curve is constructed based on these parameters. An initial configuration parameter set for the equivalent circuit of the high-voltage transmission line is set, and multiple equivalent line impedances under the initial configuration parameter set are calculated. Then, equivalent impedance curves for each equivalent line impedance are generated, and the error is compared between the true impedance curve and each equivalent impedance curve to determine the optimal equivalent line impedance. The configuration parameters corresponding to the optimal equivalent line impedance are output as the optimal configuration parameters for the equivalent circuit of the high-voltage transmission line. By employing the technical solution provided by this invention, on the one hand, the accuracy of the equivalent modeling of high-voltage transmission lines is improved, especially the impedance fitting accuracy in the low-frequency band, which is significantly improved compared to the traditional π-type circuit. This provides a more accurate and simpler equivalent transmission circuit model for power system modeling and calculation, improving the accuracy and efficiency of power system calculation and analysis. On the other hand, the automatic configuration of parameters for the equivalent circuit of high-voltage transmission lines proposed in this invention can be completed automatically by computer, without the need for professional electrical design experts to manually design and calculate system parameters. It can also ensure that the highest accuracy of line impedance equivalence is achieved with the fewest number of π-type circuits cascaded, saving manpower and time and greatly improving efficiency.

[0118] For better illustration, refer to Figure 9 This diagram illustrates the overall flow of an equivalent circuit optimization design method for high-voltage transmission lines according to an embodiment of the present invention. It should be noted that this embodiment only provides a brief overview of the general flow of the equivalent circuit optimization design for high-voltage transmission lines. The specific implementation process of each step can be understood by referring to the relevant content in the foregoing embodiments, and will not be elaborated upon here. It is understood that the present invention does not impose any limitations on this.

[0119] Determine the key line parameters and line connection methods of high-voltage transmission lines;

[0120] Based on the key line parameters and line connection forms, construct the true impedance curve of the high-voltage transmission line;

[0121] Set the initial configuration parameter set for the equivalent circuit of the high-voltage transmission line;

[0122] Intelligent configuration of line impedance is performed based on the initial configuration parameter set to obtain the optimal equivalent line impedance with the smallest error.

[0123] Determine whether the optimal equivalent line impedance meets the design requirements;

[0124] If so, output the configuration parameters corresponding to the optimal equivalent line impedance as the optimal configuration parameters for the equivalent circuit of the high-voltage transmission line.

[0125] If not, proceed to the step of setting the initial configuration parameter set for the equivalent circuit of the high-voltage transmission line.

[0126] Reference Figure 10 The diagram illustrates a structural block diagram of an equivalent circuit optimization design device for high-voltage transmission lines provided by an embodiment of the present invention, which may specifically include:

[0127] The real impedance curve construction unit 1001 is used to obtain the initial line parameters of the high-voltage transmission line and construct the real impedance curve based on the initial line parameters.

[0128] The equivalent line impedance calculation unit 1002 is used to obtain the initial configuration parameter set of the equivalent circuit of the high-voltage transmission line and calculate multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0129] The optimal equivalent line impedance determination unit 1003 is used to generate the equivalent impedance curves of each of the equivalent line impedances, and to determine the optimal equivalent line impedance by comparing the error between the actual impedance curve and multiple equivalent impedance curves.

[0130] The optimal configuration parameter output unit 1004 is used to output the configuration parameters corresponding to the optimal equivalent line impedance, as the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0131] In one optional embodiment, the equivalent circuit of the high-voltage transmission line is composed of several π-type circuits and several auxiliary circuits connected in series; the initial configuration parameter set includes the initial configuration parameters of the several π-type circuits and several auxiliary circuits under different parameter configurations; the equivalent line impedance calculation unit 1002 includes:

[0132] The line end impedance calculation unit is used to calculate the line end impedance of the equivalent circuit based on the initial configuration parameters for each of the initial configuration parameters.

[0133] The parallel superimposed impedance calculation unit is used to arrange the plurality of π-type circuits in order of connection with the line end impedance from near to far, starting from the line end impedance, and to calculate the parallel superimposed impedance from the line end impedance to the last π-type circuit by adopting the parallel superimposed calculation method one by one.

[0134] The equivalent line impedance calculation subunit is used to start from the parallel superimposed impedance, arrange the several auxiliary circuits in the order of connection with the parallel superimposed impedance from near to far, and calculate the series superimposed impedance from the parallel superimposed impedance to the last auxiliary circuit by adopting the series superimposed calculation method one by one, as the equivalent line impedance under the initial configuration parameters.

[0135] An equivalent line impedance integration unit is used to integrate the equivalent line impedances corresponding to each of the initial configuration parameters, and to serve as multiple equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

[0136] In one optional embodiment, the optimal equivalent line impedance determination unit 1003 includes:

[0137] An error calculation unit is used to calculate the error between the equivalent impedance curve and the corresponding impedance points on the true impedance curve.

[0138] The optimal equivalent line impedance determination sub-unit is used to determine the equivalent line impedance corresponding to the equivalent impedance curve with the smallest error and that meets the preset error conditions as the optimal equivalent line impedance.

[0139] In one alternative embodiment, the device further includes:

[0140] The equivalent line impedance recalculation unit is used to re-acquire the adjusted new initial configuration parameter set when the minimum error still cannot meet the preset error condition, and recalculate the equivalent line impedance based on the new initial configuration parameter set.

[0141] In one optional embodiment, the equivalent circuit of the high-voltage transmission line is composed of several π-type circuits and several auxiliary circuits connected in series; the device further includes:

[0142] The parameter optimization configuration unit is used to optimize the initial configuration parameter set through a genetic evolution algorithm when the scale of the π-type circuit and auxiliary circuit in the equivalent circuit of the high-voltage transmission line is greater than or equal to a preset scale condition, so as to obtain the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

[0143] In one optional embodiment, the process of optimizing the initial configuration parameter set using a genetic evolution algorithm in the parameter optimization configuration unit includes:

[0144] Step S1: Initialize a population based on the initial configuration parameter set, and determine the dimension and value boundary of the initial configuration parameter set during optimization iteration based on the initial line parameters. Determine the population mutation scale based on the degree of influence of each parameter variable in the initial configuration parameter set on the line impedance.

[0145] Step S2: Perform population mutation on the pre-mutation population at the specified population mutation scale to obtain the post-mutation population;

[0146] Step S3: According to the preset population crossover ratio, randomly select new samples from the mutated population to replace the old samples in the pre-mutated population to obtain a mutated crossover population; the mutated crossover population corresponds to the optimized configuration parameter set;

[0147] Step S4: Based on the optimized configuration parameter set and the actual impedance curve, construct the error matrix;

[0148] Step S5: Select multiple target errors from the error matrix based on preset error screening conditions, and select the optimal population from the mutated crossover population according to the multiple target errors;

[0149] Step S6: Determine whether the iteration termination condition is met. If not, use the optimal population as the pre-mutation population for the next iteration and proceed to step S2. If yes, determine the configuration parameter corresponding to the minimum error from the optimal population and use it as the optimal configuration parameter for the equivalent circuit of the high-voltage transmission line.

[0150] In one optional embodiment, the initial line parameters include the key line parameters and line connection forms of the high-voltage transmission line; the true impedance curve construction unit 1001 includes:

[0151] The line distributed parameter model construction unit is used to construct the electromagnetic transient simulation model of the high-voltage transmission line through electromagnetic transient simulation based on the key line parameters and the line connection form.

[0152] The frequency scanning unit is used to obtain the actual impedance curve of the high-voltage transmission line by frequency scanning based on the electromagnetic transient simulation model.

[0153] As the device embodiment is basically similar to the method embodiment, it is described in a relatively simple way. For relevant details, please refer to the description of the method embodiment above.

[0154] This invention also provides an electronic device, which includes a processor and a memory:

[0155] The memory is used to store program code and transfer the program code to the processor;

[0156] The processor is used to execute the equivalent circuit optimization design method for high-voltage transmission lines according to the instructions in the program code of any embodiment of the present invention.

[0157] This invention also provides a computer-readable storage medium for storing program code, which is used to execute the equivalent circuit optimization design method for high-voltage transmission lines according to any embodiment of this invention.

[0158] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0159] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this invention are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0160] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units through some interfaces, and may be electrical, mechanical, or other forms.

[0161] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0162] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0163] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0164] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimal design of an equivalent circuit of a high voltage transmission line, characterized in that, The method comprises the following steps: obtaining initial line parameters of a high-voltage transmission line, and constructing a real impedance curve according to the initial line parameters; obtaining an initial configuration parameter set of an equivalent circuit of the high-voltage transmission line, and calculating a plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set; generating an equivalent impedance curve for each of the equivalent line impedances, and determining an optimal equivalent line impedance by comparing errors between the real impedance curve and a plurality of the equivalent impedance curves; outputting configuration parameters corresponding to the optimal equivalent line impedance as optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

2. The method for optimal design of an equivalent circuit of a high-voltage transmission line according to claim 1, characterized in that, The equivalent circuit of the high-voltage transmission line is composed of a plurality of π-type circuits and a plurality of auxiliary circuits in series; the initial configuration parameter set includes initial configuration parameters of the plurality of π-type circuits and the plurality of auxiliary circuits under different parameter configurations; The calculation of the plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set comprises: for each initial configuration parameter, calculating the line end impedance of the equivalent circuit based on the initial configuration parameter; arranging the plurality of π-type circuits in the order of connection from the line end impedance to the last π-type circuit, and calculating the parallel superposition impedance from the line end impedance to the last π-type circuit by using the one-by-one parallel superposition calculation method; arranging the plurality of auxiliary circuits in the order of connection from the parallel superposition impedance to the last auxiliary circuit, and calculating the series superposition impedance from the parallel superposition impedance to the last auxiliary circuit by using the one-by-one series superposition calculation method, as the equivalent line impedance under the initial configuration parameter; integrating the equivalent line impedances corresponding to each initial configuration parameter as the plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set.

3. The method of optimal design of an equivalent circuit of a high-voltage transmission line according to claim 1, characterized in that, The determination of the optimal equivalent line impedance by comparing errors between the real impedance curve and a plurality of the equivalent impedance curves comprises: for each equivalent impedance curve, calculating the error between the equivalent impedance curve and the real impedance curve; the equivalent line impedance corresponding to the equivalent impedance curve with the minimum error and meeting the preset error condition is taken as the optimal equivalent line impedance.

4. The method for optimal design of an equivalent circuit of a high-voltage transmission line according to claim 3, characterized in that, The method further comprises: when the minimum error still fails to meet the preset error condition, a new initial configuration parameter set after adjustment is obtained again, and the equivalent line impedance is recalculated based on the new initial configuration parameter set.

5. The method of optimal design of an equivalent circuit of a high voltage transmission line according to claim 1, characterized in that, The equivalent circuit of the high-voltage transmission line is composed of a plurality of π-type circuits and a plurality of auxiliary circuits in series; the method further comprises: when the scale of the π-type circuits and the auxiliary circuits in the equivalent circuit of the high-voltage transmission line is greater than or equal to a preset scale condition, the initial configuration parameter set is optimized and configured by using a genetic evolution algorithm to obtain the optimal configuration parameters of the equivalent circuit of the high-voltage transmission line.

6. The method for optimal design of an equivalent circuit of a high-voltage transmission line according to claim 5, characterized in that, The process of optimizing and configuring the initial configuration parameter set by using the genetic evolution algorithm comprises: Step S1: initialize a population according to the initial configuration parameter set, and determine the dimension and value boundary of the initial configuration parameter set in the optimization iteration according to the initial line parameter, and determine the population mutation scale according to the influence degree of each parameter variable in the initial configuration parameter set on the line impedance; Step S2: perform population mutation on the pre-mutation population under the population mutation scale to obtain a post-mutation population; Step S3: replace the old samples in the pre-mutation population with new samples randomly selected from the post-mutation population according to a preset population crossover proportion value to obtain a post-mutation and crossover population; the post-mutation and crossover population corresponds to an optimized configuration parameter set; Step S4: based on the optimized configuration parameter set, an error matrix is constructed in combination with the real impedance curve; Step S5: based on a preset error screening condition, a plurality of target errors are screened from the error matrix, and an optimal population is screened from the post-mutation and crossover population according to the plurality of target errors; Step S6: determine whether the current satisfies an iteration termination condition, if not, the optimal population is taken as the pre-mutation population for the next iteration, and step S2 is executed; if yes, the configuration parameter corresponding to the minimum error is determined from the optimal population, and is taken as the optimal configuration parameter of the equivalent circuit of the high-voltage transmission line.

7. The method for the optimal design of an equivalent circuit of a high-voltage transmission line according to any one of claims 1 to 6, characterized in that, The initial line parameter includes a key line parameter and a line connection form of the high-voltage transmission line; The real impedance curve is constructed according to the initial line parameter, including: An electromagnetic transient simulation model of the high-voltage transmission line is constructed through electromagnetic transient simulation according to the key line parameter and the line connection form; The real impedance curve of the high-voltage transmission line is obtained through frequency scanning based on the electromagnetic transient simulation model.

8. An equivalent circuit optimization design device for a high voltage transmission line, characterized by comprising: It includes: A real impedance curve construction unit is configured to obtain an initial line parameter of a high-voltage transmission line, and construct a real impedance curve according to the initial line parameter; An equivalent line impedance calculation unit is configured to obtain an initial configuration parameter set of an equivalent circuit of the high-voltage transmission line, and calculate a plurality of equivalent line impedances of the equivalent circuit under the initial configuration parameter set; An optimal equivalent line impedance determination unit is configured to generate an equivalent impedance curve of each of the equivalent line impedances, and determine an optimal equivalent line impedance according to error comparison between the real impedance curve and a plurality of the equivalent impedance curves; An optimal configuration parameter output unit is configured to output a configuration parameter corresponding to the optimal equivalent line impedance as an optimal configuration parameter of an equivalent circuit of the high-voltage transmission line.

9. An electronic device, comprising: The device includes a processor and a memory: The memory is configured to store program code and transmit the program code to the processor; The processor is configured to execute the high-voltage transmission line equivalent circuit optimization design method according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store program code for executing the high-voltage transmission line equivalent circuit optimization design method. The computer readable storage medium is configured to store program code for executing the high-voltage transmission line equivalent circuit optimization design method.

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