Asymmetric flexible interconnection AC / DC hybrid power distribution network planning method

Abstract

The invention provides an asymmetric flexible interconnection alternating current and direct current hybrid power distribution network planning method, which comprises the steps of performing operation evaluation on a medium-voltage power distribution network to obtain current situation evaluation data; predicting a power load increase trend based on the historical data of the power grid and a load increase model to obtain load prediction data; planning based on flexible interconnection is carried out based on the current situation evaluation data and the load prediction data, and a flexible interconnection unit connected with the medium-voltage power distribution network is determined; and establishing a cost control curve corresponding to the flexible interconnection unit based on a preset network topology optimization strategy, and determining configuration data corresponding to the flexible interconnection unit based on the cost control curve. According to the invention, the power supply reliability of the 6kV radial power distribution network and the economical efficiency of the flexible interconnection system are improved.

Description

Technical Field

[0001] The present invention relates to power grid planning technology, and in particular to an asymmetric flexible interconnected AC / DC hybrid distribution network planning method. Background Art

[0002] With the progress in the research on topology, modulation and related control theory of flexible interconnection technology for medium-voltage distribution networks, domestic research has gradually entered the engineering demonstration stage from laboratory prototypes.

[0003] In recent years, my country has built a number of AC / DC hybrid active distribution network demonstration projects based on medium-voltage flexible DC interconnection, which have theoretical and practical guiding significance for the future large-scale construction of DC distribution networks. The world's first multi-terminal flexible DC project, the Nan'ao Multi-Terminal Flexible DC Demonstration Project, successfully connected the wind farm to the grid and explored the key issues of flexible DC technology in improving the urban power supply voltage level, expanding the power grid and promoting the consumption of renewable energy. The first medium-voltage five-terminal flexible DC distribution demonstration project in China was officially put into trial operation in Guizhou in 2019, and a flexible AC / DC interconnection distribution center integrating smart energy was established. In order to actively explore new directions for smart energy construction, my country has successfully built and put into operation the world's largest multi-terminal AC / DC hybrid flexible distribution network interconnection project, the Zhuhai Tangjiawan Multi-Terminal Flexible DC Distribution Project, and the Zhangbei Data Center Demonstration Project with coexisting AC and DC loads, realizing the interconnection and mutual assistance of power supply areas and friendly access of DER.

[0004] In addition, the Suzhou Industrial Park Active Distribution Network Demonstration Project (16MW two-port cross-regional interconnection + 8MW four-port flexible interconnection), Hangzhou Jiangdong New City Intelligent Flexible DC Distribution Network Demonstration Project (10 / 20kV three-port interconnection), Nanjing Distribution Network Flexible Interconnection Construction Project (5MW back-to-back medium voltage interconnection), Jiangsu Wujiang Yangtze River Delta Integrated Cross-Provincial Medium Voltage Flexible Interconnection Project (5MW back-to-back medium voltage interconnection), Wuxi Taihu New City Energy Internet Transformation Project (10MW series compensation medium voltage interconnection), Beijing Yanqing Multi-terminal Flexible Closed-loop Medium Voltage Distribution Project (three-port back-to-back medium voltage interconnection), Guangzhou Foshan Intelligent Distribution Flexible Multi-state Switch Project (three-port back-to-back medium voltage interconnection), Shandong Weihai Huancui District Honeycomb Internet Rack Upgrade and Transformation Demonstration Project (3MW back-to-back medium voltage interconnection), Quanzhou Nan'an Flexible Direct Interconnection Feeder Type Grid Demonstration Project (3MW back-to-back medium voltage interconnection), Ningxia Guyuan Medium Voltage Long Line Flexible Closed-loop Demonstration Project (3MW back-to-back medium voltage interconnection), Huzhou Deqing Flexible AC Controllable Interconnection Device Demonstration Project (10kV / 5MW D-UPFC) and other projects have been completed and put into operation, and the system is in good operating condition, which has effectively improved the distribution network's access capacity and emergency support capacity for large-scale new energy and electric vehicle loads, and greatly improved the power supply reliability of the medium-voltage distribution network.

[0005] The inventors found in their research that the technologies and equipment related to AC / DC hybrid distribution networks have developed rapidly in recent years, but the problems in the planning of AC / DC hybrid distribution networks have not been fundamentally solved. The layout and access of flexible interconnection devices in medium-voltage distribution networks are subject to multiple factors such as system flow constraints, capacity and regulation capacity constraints, and economic constraints. Due to the differences in distribution network parameters, load distribution, and the uncertainty of distributed power output, the different locations where the medium-voltage flexible interconnection system is connected to the distribution network will have a great impact on its operating performance and flow control strategy. Therefore, how to comprehensively consider the interactive effects of multiple factors such as the performance of flexible interconnection devices, distributed power access, and configuration costs, and improve the economy and efficiency of the layout and access of flexible closed-loop devices in distribution networks, is a corresponding field problem that needs to be solved urgently. Summary of the invention

[0006] Based on the above problems, the present invention is proposed to provide an asymmetric flexible interconnected AC / DC hybrid distribution network planning method that overcomes the above problems or at least partially solves the above problems.

[0007] According to one aspect of the present invention, a method for planning an asymmetric flexible interconnected AC / DC hybrid distribution network is provided, comprising the following steps:

[0008] A method for planning an asymmetric flexible interconnected AC / DC hybrid distribution network, characterized by comprising the following steps:

[0009] Conducting operation evaluation on the 6kV radial distribution network and the 10kV opposite-side line included in the medium-voltage distribution network to obtain status evaluation data;

[0010] Predicting the power load growth trend of the 6kV radial distribution network based on the historical data of the power grid and a pre-established load growth model, and obtaining load prediction data corresponding to the 6kV radial distribution network;

[0011] Based on the current status assessment data and the load forecast data, the medium voltage distribution network is planned based on flexible interconnection, and a flexible interconnection unit connected to the medium voltage distribution network is determined;

[0012] A cost control curve corresponding to the flexible interconnection unit is established based on a preset network topology optimization strategy, and configuration data corresponding to the flexible interconnection unit is determined based on the cost control curve.

[0013] Optionally, in the method according to the present invention, an operation evaluation is performed on the 6 kV radial distribution network and the 10 kV opposite line included in the medium voltage distribution network to obtain status evaluation data, including:

[0014] Based on the first evaluation strategy, an operation evaluation is performed on the 6kV radial distribution network included in the medium voltage distribution network to obtain first evaluation data corresponding to the 6kV radial distribution network;

[0015] Performing an operation evaluation on a 10 kV opposite-side line included in the medium-voltage distribution network based on a second evaluation strategy to obtain second evaluation data corresponding to the 10 kV opposite-side line;

[0016] Retrieving a first weight value and a second weight value, and performing a product calculation based on the first evaluation data and the first weight value, and performing a product calculation based on the second evaluation data and the second weight value, to obtain a corresponding first evaluation value and a corresponding second evaluation value;

[0017] The first evaluation value and the second evaluation value are summed and calculated, and the obtained total evaluation value is determined as the current status evaluation data corresponding to the medium voltage distribution network.

[0018] Optionally, in the method according to the present invention, an operation evaluation is performed on a 6 kV radial distribution network included in the medium voltage distribution network based on a first evaluation strategy to obtain first evaluation data corresponding to the 6 kV radial distribution network, including:

[0019] Based on the 6kV radial distribution network, corresponding power operation data is acquired and summarized into the 6kV first evaluation group, wherein the power operation data includes substation data, distribution data and load data;

[0020] Based on the 6kV radial distribution network, corresponding distribution equipment data is acquired and summarized into the 6kV second evaluation group, wherein the distribution equipment data includes operation data and maintenance data corresponding to transformer equipment, circuit breaker equipment and distribution network switch equipment respectively;

[0021] Based on the 6kV radial distribution network, corresponding load operation data is acquired and summarized to the 6kV third evaluation group, wherein the load operation data includes at least one of historical load data, load curve data and load distribution data;

[0022] The power reference data, equipment reference data and load reference data corresponding to the power operation data, distribution equipment data and load operation data respectively are retrieved, and the data are compared to obtain the first evaluation data corresponding to the 6kV radial distribution network.

[0023] Optionally, in the method according to the present invention, an operation evaluation is performed on a 10 kV radial distribution network included in the medium voltage distribution network based on a second evaluation strategy to obtain second evaluation data corresponding to the 10 kV radial distribution network, including:

[0024] Based on the 10kV radial distribution network, corresponding line operation data is acquired and summarized into a 10kV first evaluation group, wherein the line operation data includes at least one of line design data, line specification data and line construction data;

[0025] Based on the 10kV radial distribution network, corresponding line equipment data is acquired and summarized into a 10kV second evaluation group, wherein the line equipment data includes at least one of specification data and parameter data corresponding to transformer equipment, circuit breaker equipment and protection equipment respectively;

[0026] Based on the 10kV radial distribution network, the corresponding line historical data is acquired and summarized into the 10kV third evaluation group, wherein the line historical data includes at least one of historical operation data, historical load data, historical fault data and historical maintenance data;

[0027] The operation benchmark data, equipment benchmark data and historical benchmark data corresponding to the line operation data, line equipment data and line historical data are retrieved, and data comparison is performed between the data to obtain second evaluation data corresponding to the 10kV radial distribution network.

[0028] Optionally, in the method according to the present invention, the first evaluation value and the second evaluation value are summed and the obtained total evaluation value is determined as the current status evaluation data corresponding to the medium voltage distribution network, including:

[0029] The first evaluation value and the second evaluation value are summed to obtain a summed evaluation value, and a preset evaluation weight is retrieved;

[0030] Calculate the product of the evaluation sum value and the preset evaluation weight, and determine the obtained evaluation total value as the current status evaluation data corresponding to the medium voltage distribution network;

[0031] The actual status data corresponding to the medium voltage distribution network in the PMS system is obtained, and the actual status data is compared with the current status assessment data, and the preset assessment weight is updated based on the comparison result.

[0032] Optionally, in the method according to the present invention, updating the preset evaluation weight based on the comparison result includes:

[0033] When the actual status data is greater than the current status evaluation data, increasing training is performed on the preset evaluation weight;

[0034] When the current actual data is less than the current evaluation data, performing reduction training on the preset evaluation value;

[0035] The preset evaluation weight after training is obtained by the following formula:

[0036]

[0037] Among them, q1 is the preset evaluation weight k s The number of times of increasing training is performed, ∈ is the preset evaluation weight k s The training constant value, q2 is the preset evaluation weight k s To reduce the number of training, k w The preset evaluation weights after training.

[0038] Optionally, in the method according to the present invention, the power load growth trend of the 6kV radial distribution network is predicted based on the historical data of the power grid and a pre-established load growth model to obtain load prediction data corresponding to the 6kV radial distribution network, including:

[0039] Acquire historical power grid data corresponding to the 6kV radial distribution network, wherein the historical power grid data includes load curve data, electric power data, and load peak and valley value data;

[0040] Cleaning the historical data of the power grid to obtain cleaned data;

[0041] Based on the cleaned data, data integration based on the same time period is performed to obtain data sets corresponding to different time periods;

[0042] Establishing an initial machine model, and training the initial machine model based on a training set to obtain a load growth model;

[0043] The data sets corresponding to different time periods are respectively input into the load growth model for prediction, so as to obtain load prediction data corresponding to the 6kV radial distribution network.

[0044] Optionally, in the method according to the present invention, the initial machine model includes one of a linear regression model, a polynomial regression model, a time series analysis model and a machine learning model.

[0045] Optionally, in the method according to the present invention, establishing a cost control curve corresponding to the flexible interconnection unit based on a preset network topology optimization strategy, and determining configuration data corresponding to the flexible interconnection unit based on the cost control curve, comprises:

[0046] Based on graph theory and optimization algorithms, determine the quantity configuration interval corresponding to the flexible interconnected unit and the configuration reliability rates corresponding to the configuration quantities in the quantity configuration interval, determine the construction costs corresponding to the configuration quantities, and establish a construction cost control curve corresponding to the flexible interconnected unit based on the configuration reliability rates and the construction costs;

[0047] Obtaining a preset reliability interval, and obtaining curve segments corresponding to each preset reliability rate in the preset reliability interval in the cost control curve;

[0048] The construction cost and configuration reliability rate with the minimum corresponding slope are obtained in the curve line segment, and the construction cost and configuration reliability rate are determined as configuration data corresponding to the flexible interconnection unit.

[0049] According to the solution of the present invention, in the process of planning a medium-voltage distribution network based on flexible interconnection, the corresponding operation evaluation of the medium-voltage distribution network can be first performed to obtain corresponding current status evaluation data; then, the corresponding power grid historical data and load growth model are obtained to predict the power load growth trend of the medium-voltage distribution network, and then the load prediction data is obtained; and after obtaining the corresponding current status evaluation data and load prediction data, the planning of flexible interconnection can be completed, so as to determine the configuration requirements for the flexible interconnection unit; finally, by obtaining the corresponding cost control curve, the configuration data corresponding to the flexible interconnection unit can be determined; the planning method of the present invention can improve the power supply reliability of the 6kV radial distribution network, and can select matching flexible interconnection units for configuration based on cost considerations, thereby further improving the economy of the flexible interconnection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A flow chart of a method for planning an asymmetric flexible interconnected AC / DC hybrid distribution network according to an embodiment of the present invention is shown;

[0051] Figure 2 A schematic diagram of the cost control curve in this embodiment is shown. DETAILED DESCRIPTION

[0052] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0053] With the progress in the research on topology, modulation and related control theory of flexible interconnection technology for medium-voltage distribution networks, domestic research has gradually entered the engineering demonstration stage from laboratory prototypes.

[0054] In recent years, my country has built a number of demonstration projects of AC / DC hybrid active distribution networks based on flexible DC interconnection, which have theoretical and practical guiding significance for the future large-scale construction of DC distribution networks. The world's first multi-terminal flexible DC project, the Nan'ao Multi-Terminal Flexible DC Demonstration Project, successfully connected the wind farm to the grid and explored the key issues of flexible DC technology in improving the urban power supply voltage level, expanding the power grid and promoting the consumption of renewable energy. The first domestic medium-voltage five-terminal flexible DC distribution demonstration project was officially put into trial operation in Guizhou in 2019, and a flexible AC / DC interconnection distribution center integrating smart energy was established. In order to actively explore new directions for smart energy construction, my country has successfully built and put into operation the world's largest multi-terminal AC / DC hybrid flexible distribution network interconnection project, the Zhuhai Tangjiawan Multi-Terminal Flexible DC Distribution Project, and the Zhangbei Data Center Demonstration Project with coexisting AC and DC loads, realizing the interconnection and mutual assistance of power supply areas and friendly access of DER.

[0055] In addition, the Suzhou Industrial Park Active Distribution Network Demonstration Project (16MW two-port cross-regional interconnection + 8MW four-port flexible interconnection), Hangzhou Jiangdong New City Intelligent Flexible DC Distribution Network Demonstration Project (10 / 20kV three-port interconnection), Nanjing Distribution Network Flexible Interconnection Construction Project (5MW back-to-back medium voltage interconnection), Jiangsu Wujiang Yangtze River Delta Integrated Cross-Provincial Medium Voltage Flexible Interconnection Project (5MW back-to-back medium voltage interconnection), Wuxi Taihu New City Energy Internet Transformation Project (10MW series compensation medium voltage interconnection), Beijing Yanqing Multi-terminal Flexible Closed-loop Medium Voltage Distribution Project (three-port back-to-back medium voltage interconnection), Guangzhou Foshan Intelligent Distribution Flexible Multi-state Switch Project (three-port back-to-back medium voltage interconnection), Shandong Weihai Huancui District Honeycomb Internet Rack Upgrade and Transformation Demonstration Project (3MW back-to-back medium voltage interconnection), Quanzhou Nan'an Flexible Direct Interconnection Feeder Type Grid Demonstration Project (3MW back-to-back medium voltage interconnection), Ningxia Guyuan Medium Voltage Long Line Flexible Closed-loop Demonstration Project (3MW back-to-back medium voltage interconnection), Huzhou Deqing Flexible AC Controllable Interconnection Device Demonstration Project (10kV / 5MW D-UPFC) and other projects have been completed and put into operation, and the system is in good operating condition, which has effectively improved the distribution network's access capacity and emergency support capacity for large-scale new energy and electric vehicle loads, and greatly improved the power supply reliability of the medium-voltage distribution network.

[0056] The inventors found in their research that the technologies and equipment related to AC / DC hybrid distribution networks have developed rapidly in recent years, but the problems in the planning of AC / DC hybrid distribution networks have not been fundamentally solved. The layout and access of flexible interconnection devices in medium-voltage distribution networks are subject to multiple factors such as system flow constraints, capacity and regulation capacity constraints, and economic constraints. Due to the differences in distribution network parameters, load distribution, and the uncertainty of distributed power output, the different locations where the medium-voltage flexible interconnection system is connected to the distribution network will have a great impact on its operating performance and flow control strategy. Therefore, how to comprehensively consider the interactive effects of multiple factors such as the performance of flexible interconnection devices, distributed power access, and configuration costs, and improve the economy and efficiency of the layout and access of flexible closed-loop devices in distribution networks, is a corresponding field problem that needs to be solved urgently.

[0057] To solve the above problems in the prior art, the inventor proposes the solution of the present invention. An embodiment of the present invention provides a method for planning an asymmetric flexible interconnected AC / DC hybrid distribution network, which can be executed in a computing device.

[0058] Figure 1 A flow chart of a medium-voltage distribution network flexible interconnection planning method according to an embodiment of the present invention is shown, and the method is suitable for execution in a computing device, wherein the computing device can be understood as a terminal with data processing capabilities, such as a mobile phone or a computer.

[0059] like Figure 1 As shown, the present embodiment proposes an asymmetric flexible interconnected AC / DC hybrid distribution network planning method, which starts at step S102. In step S102, the following contents are included:

[0060] The operation evaluation is performed on the 6kV radial distribution network and the 10kV opposite-side line included in the medium-voltage distribution network to obtain current status evaluation data.

[0061] For example, in this embodiment, the voltage level of the medium voltage distribution network can correspond to 6kV / 10kV, which specifically includes a corresponding 6kV radial distribution network and a corresponding 10kV radial distribution network; here, after completing the determination of the radial distribution network and the opposite side line, the corresponding operation evaluation can be carried out to obtain the corresponding current status evaluation data.

[0062] Further, in this embodiment, the above-mentioned “performing operation evaluation on the 6 kV radial distribution network and the 10 kV radial distribution network included in the medium voltage distribution network respectively to obtain status evaluation data” may also include the following steps:

[0063] Based on the first evaluation strategy, an operation evaluation is performed on the 6kV radial distribution network included in the medium voltage distribution network to obtain first evaluation data corresponding to the 6kV radial distribution network;

[0064] Based on the second evaluation strategy, an operation evaluation is performed on the 10 kV radial distribution network included in the medium voltage distribution network to obtain second evaluation data corresponding to the 10 kV radial distribution network;

[0065] Retrieving a first weight value and a second weight value, and performing a product calculation based on the first evaluation data and the first weight value, and performing a product calculation based on the second evaluation data and the second weight value, to obtain a corresponding first evaluation value and a corresponding second evaluation value;

[0066] The first evaluation value and the second evaluation value are summed and calculated, and the obtained total evaluation value is determined as the current status evaluation data corresponding to the medium voltage distribution network.

[0067] For example, in this embodiment, since the grid structures of the radial distribution network and the opposite line corresponding to the same medium-voltage distribution network are different, different evaluation strategies can be configured based on the difference between the two; that is, when performing an operation evaluation on the medium-voltage distribution network, the operation evaluation of the 6kV radial distribution network can be performed based on the first evaluation strategy to obtain the first evaluation data corresponding to the radial distribution network, and the operation evaluation of the 10kV opposite line can be performed based on the second evaluation strategy to obtain the second evaluation data corresponding to the opposite line; by performing different operation evaluations on the radial distribution network and the opposite line with different grid structures based on different evaluation strategies, the operation evaluation can be improved. The corresponding evaluation accuracy; further, after obtaining the corresponding first evaluation data and the second evaluation data, since the radial distribution network and the opposite line have different important proportions in the medium-voltage distribution network, the corresponding first weight value and the second weight value can be set in advance, wherein the sum of the first weight value and the second weight value is 1; further, when retrieving the corresponding first weight value and the second weight value, the corresponding evaluation data can be multiplied by the corresponding weight value to obtain the corresponding first evaluation value and the second evaluation value; finally, the first evaluation value and the second evaluation value can be summed and the obtained total evaluation value can be determined as the current status evaluation data of the corresponding medium-voltage distribution network.

[0068] Furthermore, in this embodiment, the above-mentioned “performing an operation evaluation on the 6kV radial distribution network included in the medium voltage distribution network based on the first evaluation strategy to obtain first evaluation data corresponding to the 6kV radial distribution network” may also include the following steps:

[0069] Based on the 6kV radial distribution network, corresponding power operation data is acquired and summarized into a 6kV first evaluation group, wherein the power operation data includes at least one of substation data, distribution data and load data;

[0070] Based on the 6kV radial distribution network, corresponding distribution equipment data is acquired and summarized into the 6kV second evaluation group, wherein the distribution equipment data includes operation data and maintenance data corresponding to transformer equipment, circuit breaker equipment and distribution network switch equipment respectively;

[0071] Based on the 6kV radial distribution network, corresponding load operation data is acquired and summarized to the 6kV third evaluation group, wherein the load operation data includes at least one of historical load data, load curve data and load distribution data;

[0072] The power reference data, equipment reference data and load reference data corresponding to the power operation data, distribution equipment data and load operation data are retrieved, and data comparison is performed between the data to obtain the first evaluation data corresponding to the 6kV radial distribution network.

[0073] For example, in this embodiment, based on the grid structure of the radial distribution network, corresponding power operation data, distribution equipment data and load operation data can be obtained, wherein the power operation data includes at least one of substation data, distribution data and load data; the distribution equipment data includes operation data and maintenance data of transformer equipment, circuit breaker equipment and distribution network switch equipment; the load operation data includes at least one of historical load data, load curve data and load distribution data; after completing the acquisition of the corresponding data, the power benchmark data, equipment benchmark data and load benchmark data corresponding to the power operation data, distribution equipment data and load operation data respectively can be retrieved, and data comparison can be performed between the data to obtain the first evaluation data corresponding to the radial distribution network.

[0074] Similarly, in this embodiment, the above-mentioned “performing an operation evaluation on the 10 kV opposite-side line included in the medium-voltage distribution network based on the second evaluation strategy to obtain second evaluation data corresponding to the 10 kV opposite-side line” may include the following steps:

[0075] Based on the 10kV opposite-side line, corresponding line operation data is acquired and summarized into a 10kV first evaluation group, wherein the line operation data includes at least one of line design data, line specification data and line construction data;

[0076] Based on the 10kV opposite-side line, corresponding line equipment data is acquired and summarized into a 10kV second evaluation group, wherein the line equipment data includes at least one of specification data and parameter data corresponding to transformer equipment, circuit breaker equipment, and protection equipment respectively;

[0077] Based on the 10kV opposite-side line, the corresponding line historical data is acquired and summarized into the 10kV third evaluation group, wherein the line historical data includes at least one of historical operation data, historical load data, historical fault data and historical maintenance data;

[0078] The operation benchmark data, equipment benchmark data and historical benchmark data corresponding to the line operation data, line equipment data and line historical data are retrieved, and data comparison is performed between the data to obtain second evaluation data corresponding to the 10kV opposite-side line.

[0079] For example, in this embodiment, based on the grid structure of the opposite line, the corresponding line operation data, line equipment data and line historical data can be obtained, wherein the line operation data may include at least one of line design data, line specification data and line construction data; the line equipment data includes specification data and at least one of parameter data corresponding to transformer equipment, circuit breaker equipment and protection equipment respectively; after completing the acquisition of the corresponding data, the operation benchmark data, equipment benchmark data and historical benchmark data corresponding to the line operation data, line equipment data and line historical data respectively can be retrieved, and data comparison can be performed between the data to obtain second evaluation data corresponding to the opposite line.

[0080] Furthermore, in this embodiment, the above-mentioned "calculating the sum of the first evaluation value and the second evaluation value, and determining the obtained total evaluation value as the current status evaluation data corresponding to the medium voltage distribution network" may also include the following steps:

[0081] The first evaluation value and the second evaluation value are summed to obtain a summed evaluation value, and a preset evaluation weight is retrieved;

[0082] Calculate the product of the evaluation sum value and the preset evaluation weight, and determine the obtained evaluation total value as the current status evaluation data corresponding to the medium voltage distribution network;

[0083] The actual status data corresponding to the medium voltage distribution network in the PMS system is obtained, and the actual status data is compared with the current status assessment data, and the preset assessment weight is updated based on the comparison result.

[0084] For example, in this embodiment, the determination of the current status assessment data can be obtained based on the obtained first assessment value and the second assessment value, that is, by summing the first assessment value and the second assessment value to obtain the corresponding current status assessment data; and here, in order to accurately determine the corresponding current status assessment data, the corresponding preset assessment weights can be set in advance, and the assessment sum value after the first assessment value and the second assessment value are summed and multiplied by the retrieved preset assessment weights, so as to determine the obtained total assessment value as the current status assessment data corresponding to the corresponding medium-voltage distribution network; it should be noted that since the corresponding current status assessment data is obtained based on multiplying the assessment sum value and the retrieved preset assessment weights, in order to ensure that the corresponding current status assessment data has a certain degree of accuracy, the actual current status data corresponding to the medium-voltage distribution network in the PMS system can be obtained, and the corresponding actual current status data can be compared with the current status assessment data, so as to determine whether the preset assessment weights need to be updated based on the comparison results, thereby completing the iterative update of the preset assessment weights and improving the corresponding data accuracy.

[0085] Here, the above-mentioned “updating the preset evaluation weight based on the comparison result” may also include the following steps:

[0086] When the actual status data is greater than the current status evaluation data, increasing training is performed on the preset evaluation weight;

[0087] When the current actual data is less than the current evaluation data, performing reduction training on the preset evaluation value;

[0088] The preset evaluation weight after training is obtained by the following formula:

[0089]

[0090] Among them, q1 is the preset evaluation weight k s The number of times of increasing training is performed, ∈ is the preset evaluation weight k s The training constant value, q2 is the preset evaluation weight k s To reduce the number of training, k w The preset evaluation weights after training.

[0091] In step S104, the following contents are included:

[0092] The power load growth trend of the 6kV radial distribution network is predicted based on the historical data of the power grid and a pre-established load growth model to obtain load prediction data corresponding to the 6kV radial distribution network.

[0093] For example, in this embodiment, the historical data of the power grid corresponding to the 6kV radial distribution network is obtained, and the corresponding historical data of the power grid is input into the load growth model based on the pre-established load growth model to obtain the predicted load data of the 6kV radial distribution network.

[0094] Further, in this embodiment, the above-mentioned “predicting the power load growth trend of the 6kV radial distribution network based on the historical data of the power grid and the pre-established load growth model to obtain the load forecast data corresponding to the 6kV radial distribution network” may also include the following steps:

[0095] Acquire historical power grid data corresponding to the 6kV radial distribution network, wherein the historical power grid data includes load curve data, electric power data, and load peak and valley value data;

[0096] Cleaning the historical data of the power grid to obtain cleaned data;

[0097] Based on the cleaned data, data integration based on the same time period is performed to obtain data sets corresponding to different time periods;

[0098] Establishing an initial machine model, and training the initial machine model based on a training set to obtain a load growth model;

[0099] The data sets corresponding to different time periods are respectively input into the load growth model for prediction, so as to obtain the load prediction corresponding to the 6kV radial distribution network.

[0100] For example, in this embodiment, first, the corresponding power grid historical data can be obtained based on the 6kV radial distribution network, where the power grid historical data includes load curve data, power data, and load peak and valley data; then, after completing the acquisition of the power grid historical data, the corresponding data cleaning can be performed, which can specifically include removing outliers and noise, and supplementing the corresponding missing data; then, after completing the corresponding data cleaning, the obtained cleaned data can be integrated, including based on the same time period, that is, obtaining data sets corresponding to different time periods; then, an initial machine model can be established, and the initial machine model can be trained based on the obtained training set, wherein the training set includes corresponding sample data, and after completing the training of the initial machine model, the corresponding load growth model can be obtained; finally, by inputting the data sets corresponding to different time periods into the corresponding load growth model for prediction, the predicted load of the 6kV radial distribution network can be obtained.

[0101] Furthermore, in this embodiment, the initial machine model used above may include one of a linear regression model, a polynomial regression model, a time series analysis model, and a machine learning model.

[0102] In step S106, the following contents are included:

[0103] Based on the current status assessment data and the load forecast data, the medium voltage distribution network is planned based on flexible interconnection, and a flexible interconnection unit connected to the medium voltage distribution network is determined.

[0104] For example, in this embodiment, after obtaining the corresponding current status assessment data and load forecast data based on the above-mentioned method steps, since the current status assessment data can evaluate and characterize the operating status of the medium-voltage distribution network, and the load forecast data can predict the future load of the medium-voltage distribution network; therefore, based on the current status assessment data and the load forecast data, the topological structure, capacity configuration and main parameters of the flexible interconnection unit required for the medium-voltage distribution network can be calculated.

[0105] In step S108, the following contents are included: establishing a cost control curve corresponding to the flexible interconnection unit based on a preset network topology optimization strategy, and determining configuration data corresponding to the flexible interconnection unit based on the cost control curve.

[0106] For example, in this embodiment, after determining the configuration of the corresponding flexible interconnected unit based on the current status assessment data and the load forecast data, a cost control curve corresponding to the flexible interconnected unit can be established based on the corresponding preset network topology optimization strategy. The cost control curve can be understood as a data curve corresponding to the performance and cost of the flexible interconnected unit. Through this cost control curve, a good balance can be achieved between the overall cost control of the system and the improvement of power supply reliability.

[0107] Furthermore, in this embodiment, the above-mentioned “establishing a cost control curve corresponding to the flexible interconnection unit based on a preset network topology optimization strategy, and determining configuration data corresponding to the flexible interconnection unit based on the cost control curve” may also include the following steps:

[0108] Based on graph theory and optimization algorithms, determine the quantity configuration interval corresponding to the flexible interconnected unit and the configuration reliability rates corresponding to the configuration quantities in the quantity configuration interval, determine the construction costs corresponding to the configuration quantities, and establish a construction cost control curve corresponding to the flexible interconnected unit based on the configuration reliability rates and the construction costs;

[0109] Obtaining a preset reliability interval, and obtaining curve segments corresponding to each preset reliability rate in the preset reliability interval in the cost control curve;

[0110] The construction cost and configuration reliability rate with the minimum corresponding slope are obtained in the curve line segment, and the construction cost and configuration reliability rate are determined as configuration data corresponding to the flexible interconnection unit.

[0111] For example, in this embodiment, in order to construct a corresponding cost control curve, the quantity configuration interval corresponding to the flexible interconnection unit and the reliability rates of each configuration corresponding to each configuration quantity in the quantity configuration interval can be first determined based on the corresponding graph theory and optimization algorithm, wherein the quantity configuration interval corresponds to each different configuration quantity, and it can be known that the higher the configuration quantity, the higher the corresponding cost. Therefore, the corresponding cost can be obtained by corresponding to each configuration quantity, so that the correlation between each configuration reliability and each cost can be established, and the corresponding cost control curve can be constructed based on the correlation.

[0112] After the construction of the cost control curve is completed, the corresponding preset reliability interval can be obtained. Here, the preset reliability interval can be understood as the interval of the preset reliability rate that can meet the equipment requirements pre-set by the corresponding management end. Here, after obtaining the preset reliability interval, the curve segments corresponding to each preset reliability rate in the preset reliability interval can be obtained in the cost control curve;

[0113] Finally, in order to achieve a good balance between the overall cost control of the corresponding system and the improvement of power supply reliability based on the curve segment, the cost and configuration reliability with the smallest slope can be obtained in the curve segment, and the corresponding cost and configuration reliability can be used to determine the configuration data corresponding to the flexible interconnection unit.

[0114] For example, in this embodiment, the corresponding cost control curve can be as follows: Figure 2 shown.

[0115] To sum up, in this embodiment, in the process of planning the 6 / 10kV medium-voltage distribution network based on flexible interconnection, the corresponding operation evaluation of the 6 / 10kV medium-voltage distribution network can be first performed to obtain the corresponding current status evaluation data; then, the power load growth trend of the 6 / 10kV medium-voltage distribution network is predicted to obtain the load prediction data; and after obtaining the corresponding current status evaluation data and load prediction data, the planning of the flexible interconnection system can be completed, so as to determine the topological structure, capacity configuration and main parameters of the flexible interconnection unit; finally, by obtaining the corresponding cost control curve, the configuration data corresponding to the flexible interconnection unit can be determined; the planning method of this embodiment can improve the power supply reliability of the 6kV radial distribution network, and can select matching flexible interconnection units for configuration based on cost considerations, thereby further improving the economy of the flexible interconnection system.

Claims

1. A method for planning an asymmetric flexible interconnected AC / DC hybrid distribution network, characterized in that: The following steps are involved: Conducting operation evaluation on the 6kV radial distribution network and the 10kV opposite-side line included in the medium-voltage distribution network to obtain status evaluation data; Predicting the power load growth trend of the 6kV radial distribution network based on the historical data of the power grid and a pre-established load growth model, and obtaining load prediction data corresponding to the 6kV radial distribution network; Based on the current status assessment data and the load forecast data, the medium voltage distribution network is planned based on flexible interconnection, and a flexible interconnection unit connected to the medium voltage distribution network is determined; A cost control curve corresponding to the flexible interconnection unit is established based on a preset network topology optimization strategy, and configuration data corresponding to the flexible interconnection unit is determined based on the cost control curve.

2. The method for flexible interconnection planning of a medium voltage distribution network according to claim 1, characterized in that: The operation evaluation of the 6kV radial distribution network and the 10kV opposite-side line included in the medium-voltage distribution network is performed respectively to obtain the current status evaluation data, including: Based on the first evaluation strategy, an operation evaluation is performed on the 6kV radial distribution network included in the medium voltage distribution network to obtain first evaluation data corresponding to the 6kV radial distribution network; Performing an operation evaluation on a 10 kV opposite-side line included in the medium-voltage distribution network based on a second evaluation strategy to obtain second evaluation data corresponding to the 10 kV opposite-side line; Retrieving a first weight value and a second weight value, and performing a product calculation based on the first evaluation data and the first weight value, and performing a product calculation based on the second evaluation data and the second weight value, to obtain a corresponding first evaluation value and a corresponding second evaluation value; The first evaluation value and the second evaluation value are summed and calculated, and the obtained total evaluation value is determined as the current status evaluation data corresponding to the medium voltage distribution network.

3. The method for flexible interconnection planning of a medium voltage distribution network according to claim 2, characterized in that: Based on the first evaluation strategy, an operation evaluation is performed on the 6 kV radial distribution network included in the medium voltage distribution network to obtain first evaluation data corresponding to the 6 kV radial distribution network, including: Based on the 6kV radial distribution network, corresponding power operation data is acquired and summarized into a 6kV first evaluation group, wherein the power operation data includes at least one of substation data, distribution data and load data; Based on the 6kV radial distribution network, corresponding distribution equipment data is acquired and summarized into the 6kV second evaluation group, wherein the distribution equipment data includes operation data and maintenance data corresponding to transformer equipment, circuit breaker equipment and distribution network switch equipment respectively; Based on the 6kV radial distribution network, corresponding load operation data is acquired and summarized to the 6kV third evaluation group, wherein the load operation data includes at least one of historical load data, load curve data and load distribution data; The power reference data, equipment reference data and load reference data corresponding to the power operation data, distribution equipment data and load operation data are retrieved, and data comparison is performed between the data to obtain the first evaluation data corresponding to the 6kV radial distribution network.

4. The method for flexible interconnection planning of a medium voltage distribution network according to claim 2, characterized in that: Based on the second evaluation strategy, an operation evaluation is performed on the 10 kV opposite-side line included in the medium-voltage distribution network to obtain second evaluation data corresponding to the 10 kV opposite-side line, including: Based on the 10kV opposite-side line, corresponding line operation data is acquired and summarized into a 10kV first evaluation group, wherein the line operation data includes at least one of line design data, line specification data and line construction data; Based on the 10kV opposite-side line, corresponding line equipment data is acquired and summarized into a 10kV second evaluation group, wherein the line equipment data includes at least one of specification data and parameter data corresponding to transformer equipment, circuit breaker equipment, and protection equipment respectively; Based on the 10kV opposite-side line, the corresponding line historical data is acquired and summarized into the 10kV third evaluation group, wherein the line historical data includes at least one of historical operation data, historical load data, historical fault data and historical maintenance data; The operation benchmark data, equipment benchmark data and historical benchmark data corresponding to the line operation data, line equipment data and line historical data are retrieved, and data comparison is performed between the data to obtain second evaluation data corresponding to the 10kV opposite-side line.

5. The method for flexible interconnection planning of a medium voltage distribution network according to claim 2, characterized in that: The first evaluation value and the second evaluation value are summed and calculated, and the obtained total evaluation value is determined as the current status evaluation data corresponding to the medium voltage distribution network, including: The first evaluation value and the second evaluation value are summed to obtain a summed evaluation value, and a preset evaluation weight is retrieved; Calculate the product of the evaluation sum value and the preset evaluation weight, and determine the obtained evaluation total value as the current status evaluation data corresponding to the medium voltage distribution network; The actual status data corresponding to the medium voltage distribution network in the PMS system is obtained, and the actual status data is compared with the current status assessment data, and the preset assessment weight is updated based on the comparison result.

6. The method for flexible interconnection planning of a medium voltage distribution network according to claim 5, characterized in that: The preset evaluation weight is updated based on the comparison result, including: When the actual status data is greater than the current status evaluation data, increasing training is performed on the preset evaluation weight; When the current actual data is less than the current evaluation data, performing reduction training on the preset evaluation value; The preset evaluation weight after training is obtained by the following formula: Among them, q1 is the preset evaluation weight k s Increase the number of training sessions. is the preset evaluation weight k s The training constant value, q2 is the preset evaluation weight k s To reduce the number of training, k w The preset evaluation weights after training.

7. The method for flexible interconnection planning of a medium voltage distribution network according to claim 1, characterized in that: The power load growth trend of the 6kV radial distribution network is predicted based on the historical data of the power grid and the pre-established load growth model, and the load prediction data corresponding to the 6kV radial distribution network is obtained, including: Acquire historical power grid data corresponding to the 6kV radial distribution network, wherein the historical power grid data includes load curve data, electric power data, and load peak and valley value data; Cleaning the historical data of the power grid to obtain cleaned data; Based on the cleaned data, data integration based on the same time period is performed to obtain data sets corresponding to different time periods; Establishing an initial machine model, and training the initial machine model based on a training set to obtain a load growth model; The data sets corresponding to different time periods are respectively input into the load growth model for prediction, so as to obtain the load prediction corresponding to the 6kV radial distribution network.

8. The method for flexible interconnection planning of a medium voltage distribution network according to claim 7, characterized in that: The initial machine model includes one of a linear regression model, a polynomial regression model, a time series analysis model and a machine learning model.

9. The method for flexible interconnection planning of a medium voltage distribution network according to claim 1, characterized in that: Establishing a cost control curve corresponding to the flexible interconnection unit based on a preset network topology optimization strategy, and determining configuration data corresponding to the flexible interconnection unit based on the cost control curve, including: Based on graph theory and optimization algorithms, determine the quantity configuration interval corresponding to the flexible interconnected unit and the configuration reliability rates corresponding to the configuration quantities in the quantity configuration interval, determine the construction costs corresponding to the configuration quantities, and establish a construction cost control curve corresponding to the flexible interconnected unit based on the configuration reliability rates and the construction costs; Obtaining a preset reliability interval, and obtaining curve segments corresponding to each preset reliability rate in the preset reliability interval in the cost control curve; The construction cost and configuration reliability rate with the minimum corresponding slope are obtained in the curve line segment, and the construction cost and configuration reliability rate are determined as configuration data corresponding to the flexible interconnection unit.

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