Incremental distribution network load precise control method

Abstract

The application discloses an incremental power distribution network load precise control method and belongs to the technical field of power grid coordination. The application solves the problem that the existing method is difficult to evaluate the operation risk of the power grid after the energy storage is connected, leading to the difficulty in precisely controlling the incremental power distribution network load. By comparing the incremental power distribution network load with the low-voltage load shedding threshold and combining the priority of each intelligent power distribution terminal, the load is subjected to low-voltage load shedding operation, which is helpful for automatically reducing the load of the power distribution network when the frequency or voltage is abnormal, and guarantees the stable operation of the incremental power distribution network. A load control scheme is formulated to ensure that power limiting measures are taken when the incremental power distribution network load control is implemented, and the influence on the user is minimized. The operation risk of the power grid after the energy storage is connected is evaluated in advance, the cooperation scheme of the new energy under different output modes, the energy storage and the regional load in different time periods is analyzed, the optimal source-grid-load-storage control strategy is proposed, and the flexible control of the light energy storage load is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid coordination, in particular to an incremental distribution network load precise control method. BACKGROUND

[0002] The so-called incremental distribution network refers to the part of the newly added distribution network outside the distribution network already constructed by the power grid enterprise; the power grid in the power system is layered according to voltage level, the transmission network belongs to high voltage level, and the distribution network belongs to low voltage level. Generally, the power grid above 220 (330) kilovolts is a transmission network, and the following is a distribution network. The "incremental" distribution network corresponds to the "stock" concept. In recent years, with the explosive growth of new energy power generation capacity and the access of charging piles and energy storage facilities, the role and tasks to be completed by the distribution network have changed greatly. New energy storage construction, as an important part of building a new power system, is of great significance to promoting green energy transformation, ensuring power supply safety, and improving new energy consumption. Related support policies for the coordinated development of new energy storage and new energy are constantly improving, laying a foundation for the innovation and high-quality development of new energy storage technology.

[0003] However, after the new energy storage and new energy are connected to the regional power grid, it is difficult to evaluate the operation risk of the power grid after the energy storage is connected, and it is difficult to precisely control the load of the incremental distribution network, thereby reducing the coordination function of the existing incremental distribution network load.

[0004] Therefore, the existing needs are not met, and for this purpose, an incremental distribution network load precise control method is proposed. SUMMARY

[0005] The purpose of the present application is to provide an incremental distribution network load precise control method. By comparing the incremental distribution network load with the low-voltage load shedding threshold and combining the priority of each intelligent distribution terminal, the load is subjected to low-voltage load shedding operation, which helps to automatically reduce the load of the distribution network when the frequency or voltage is abnormal, ensuring the stable operation of the incremental distribution network. A load control scheme is developed to ensure that power limiting measures are taken when implementing incremental distribution network load control, minimizing the impact on users. The operation risk of the power grid after the energy storage is connected is evaluated in advance, the cooperation scheme of new energy under different output modes, energy storage, and regional load at different times is analyzed, the optimal source-grid-load-storage control strategy is proposed, and flexible control of light and energy storage is realized, solving the problems raised in the above background technology.

[0006] To achieve the above purpose, the present application provides the following technical scheme:

[0007] The incremental distribution network load precise control method comprises the following steps:

[0008] S1, establish an incremental power distribution network load management system, obtain and analyze incremental power distribution network load information in real time according to the intelligent power distribution terminal, including: the change trend, peak value and valley value of the incremental power distribution network load, and accurately predict the change of the incremental power distribution network load;

[0009] S2, establish the priority of each intelligent power distribution terminal, calculate the comprehensive score of all branch loads of the intelligent power distribution terminal according to the total amount of incremental power distribution network load uploaded by the intelligent power distribution terminal, and obtain the priority of each intelligent power distribution terminal according to the score sorting;

[0010] S3, establish a low-frequency low-voltage load shedding system, based on the total amount of incremental power distribution network load uploaded by the intelligent power distribution terminal and the priority of each intelligent power distribution terminal, pre-construct, input and adjust the low-frequency low-voltage load shedding scheme of the incremental power distribution network load, and realize the low-frequency load shedding operation of the incremental power distribution network load;

[0011] S4, establish an accident power limiting and new energy grid-connection safety and stability control system, develop a load control scheme through the accident power limiting system to ensure that the influence on users is minimized when implementing the incremental power distribution network load control; and through the cooperation of the stability control master station, stability control substation and terminal station in the new energy grid-connection safety and stability control subsystem, the controllable load of energy storage, photovoltaic power station and each substation is included in the control master station to realize flexible and accurate control of load;

[0012] S5, establish a light storage load coordination control system, evaluate the operation risk of the power grid after the access of energy storage in advance, develop safety and stability control strategy optimization analysis and commercial operation economic evaluation after the access of energy storage; analyze the coordination scheme of new energy under different output modes, energy storage, and regional load at different times, and propose the optimal source network load storage control strategy to realize light storage load flexible control.

[0013] Further, the following steps are further included:

[0014] S6, establish an information interaction platform, use a wireless transmission network as a transmission medium to make the incremental power distribution network load management system, intelligent power distribution terminal, low-frequency low-voltage load shedding system and accident power limiting and new energy grid-connection safety and stability control system interact with each other in the information interaction platform, ensure that the data interface of each system is developed to realize linkage, and optimize the incremental power distribution network load control strategy.

[0015] Further, after the establishment of the incremental power distribution network load management system in S1, the following steps are included:

[0016] Collect multiple sets of historical incremental power distribution network load information, clean and normalize the historical incremental power distribution network load information; multiple sets of historical incremental power distribution network load information are used as a sample set, and the sample set is divided into multiple training sets and test sets;

[0017] An incremental distribution network load forecasting model is constructed. The training set is imported into the incremental distribution network load forecasting model for training, and the training results are output. Then, the test set is imported into the incremental distribution network load forecasting model for testing, and the test results are output. The two results are compared to ensure that the test results are consistent with the training results. Then, the incremental distribution network load forecasting model is optimized and iterated based on different training sets and test sets to ensure the accuracy of the early warning of the incremental distribution network load forecasting model.

[0018] Furthermore, in step S1, after acquiring and analyzing the incremental distribution network load information in real time based on the intelligent distribution terminal, the following steps are included:

[0019] The incremental distribution network load information is cleaned and normalized. The pre-processed incremental distribution network load information is then imported into the incremental distribution network load early warning model for prediction. The current incremental distribution network load prediction result is then output and uploaded to the information exchange platform for data exchange via a wireless transmission network.

[0020] Furthermore, the calculation of the comprehensive score of all branch loads of the intelligent power distribution terminal in S2 specifically includes the following steps:

[0021] The loads in the incremental distribution network are classified according to their importance or power consumption characteristics into primary loads, secondary loads, tertiary loads, or industrial loads, commercial loads, and residential loads.

[0022] Based on the total incremental distribution network load at each level uploaded by each smart distribution terminal, load calculation is performed according to the total capacity of the smart distribution terminals, their operating status, and the power supply capacity of the grid to obtain the load information of each smart distribution terminal. The priority of each smart distribution terminal is determined by combining the load category to which each smart distribution terminal belongs.

[0023] Furthermore, the pre-construction, input, and adjustment of incremental distribution network load low-frequency and low-voltage load shedding schemes in S3 specifically includes the following steps:

[0024] Based on the total load of each level of incremental distribution network uploaded by the smart distribution terminal, a low-frequency and low-voltage load shedding threshold is preset. It is then determined whether the incremental distribution network load information exceeds the threshold range. If it does not exceed the threshold range, no low-frequency load shedding operation is performed. If it exceeds the threshold range, the load of a certain load category of smart distribution terminal is determined and the priority of each smart distribution terminal is considered. Based on this, an incremental distribution network load low-frequency and low-voltage load shedding scheme is formulated to restore the frequency balance of the incremental distribution network. The incremental distribution network load low-frequency and low-voltage load shedding scheme includes at least three or more types.

[0025] Further, the pre-construction, entry and adjustment of the incremental power distribution network load low-frequency low-voltage load shedding scheme in S3 further includes the following steps:

[0026] After the incremental power distribution network load low-frequency low-voltage load shedding scheme is formulated, the incremental power distribution network load low-frequency low-voltage load shedding scheme is entered into the low-frequency low-voltage load shedding system through the man-machine module belonging to the low-frequency low-voltage load shedding system, and the incremental power distribution network load low-frequency low-voltage load shedding scheme is preformed, and the deficiencies of the scheme are adjusted in time according to the preformed results to avoid grid operation errors.

[0027] Further, after the pre-construction, entry and adjustment of the incremental power distribution network load low-frequency low-voltage load shedding scheme in S3, the following steps are included:

[0028] The total amount of incremental power distribution network load of each level is calculated through the incremental power distribution network load real-time data uploaded by each intelligent power distribution terminal, the entered incremental power distribution network load low-frequency low-voltage load shedding scheme is selected according to the current incremental power distribution network load total amount, a standard low-frequency low-voltage automatic load shedding scheme report is generated, and the automatic load shedding function belonging to the low-frequency low-voltage load shedding system is controlled to switch on or off a part of load equipment in the incremental power distribution network, thereby realizing the low-frequency load shedding operation of the incremental power distribution network load.

[0029] Further, the stable control master station in the new energy grid-connected safety and stability control subsystem in S4 is located in a hub substation or a power plant, and is used to be responsible for summarizing information, forming a control strategy and sending a control command; the stable control substation is located in an important substation or a power plant, and is used to be responsible for collecting information and sending it to the master station; the terminal station executes the control command and feeds back, and through real-time monitoring and control, the stability and safety of the new energy power generation grid-connected are ensured.

[0030] Further, the light storage load coordination control system in S5 is established, and the following steps are included:

[0031] The energy storage control model and the new energy access model are constructed, the energy storage, photovoltaic power station and controllable load information of each substation included in the control master station are imported into the energy storage control model and the new energy access model for drilling, the transient safety and stability characteristics of the power grid are analyzed, the operation risk of the power grid after the energy storage is accessed is evaluated in advance, and the safety and stability control strategy of the power grid is optimized according to the analysis results.

[0032] Further, the comprehensive score of all branch loads of the intelligent power distribution terminal is calculated, including:

[0033] The load change curve of each branch load of the intelligent power distribution terminal is obtained, and the power consumption peak period parameter and the power consumption valley period parameter of each branch load are determined according to the load change curve;

[0034] Obtain multiple power consumption indexes of each branch load at a power consumption peak period parameter and a power consumption valley period parameter, respectively;

[0035] Determine a power consumption subject according to the power consumption indexes, determine a load source feature based on the power consumption subject, and determine a strong correlation feature of each branch load according to the load source feature;

[0036] Obtain a modification attribute of the strong correlation feature, and determine a modification subject of the modification attribute, wherein the modification subject includes nature and human;

[0037] Determine a peak shaving potential value or a valley flattening potential value of the strong correlation feature according to the modification subject;

[0038] Determine a load variable interval of each branch load according to the peak shaving potential value or the valley flattening potential value, and determine a load adjustment score of each branch load according to the load variable interval;

[0039] Extract an effective static response load and an effective dynamic response load of each branch load, respectively, and determine a demand response settlement score of each branch load according to the effective static response load and the effective dynamic response load;

[0040] Determine a load supply score of each branch load according to the demand response settlement score;

[0041] Obtain a power grid topology of each branch load, determine a load loss factor according to the power grid topology, and determine a load loss proportion of each branch load according to the load loss factor, power grid data, and a preset power grid utilization efficiency evaluation index;

[0042] Determine a load loss score of each branch load according to the load loss proportion, and calculate a comprehensive score of all branch loads of the intelligent power distribution terminal according to the load loss score, the load supply score, and the load adjustment score, and preset weights of the three scores.

[0043] Further, before the priority of each intelligent power distribution terminal is determined according to the scores, the following steps are further included:

[0044] Obtain a working condition parameter change of each intelligent power distribution terminal when the branch load is working, and construct a working condition disturbance linearization matrix of each intelligent power distribution terminal according to the working condition parameter change;

[0045] Obtain a minimum eigenvalue of each intelligent power distribution terminal under a current working condition according to the working condition disturbance linearization matrix;

[0046] Obtain a minimum eigenvalue of each intelligent power distribution terminal under a standard working condition, and calculate a working condition stable maintenance coefficient of each intelligent power distribution terminal according to the minimum eigenvalue of each intelligent power distribution terminal under the current working condition and the minimum eigenvalue of each intelligent power distribution terminal under the standard working condition;

[0047]

[0048] wherein S i represents the working condition stable maintenance coefficient of the i-th intelligent power distribution terminal, mu represents the linear load limit super parameter, D 1i represents the minimum eigenvalue of the i-th intelligent power distribution terminal under the current working condition, D 2i represents the minimum eigenvalue of the i-th intelligent power distribution terminal under the standard working condition, A i represents the maintenance coefficient of the i-th intelligent power distribution terminal, alpha represents the influence factor of the working condition stability margin of the intelligent power distribution terminal on the fluctuation degree of the load state variable, F i represents the number of branch loads of the i-th intelligent power distribution terminal, j represents the j-th branch load, Q 1j represents the maximum load of the j-th branch load, Q 2j represents the minimum load of the i-th branch load;

[0049] The priority evaluation weight of the working condition stable maintenance coefficient of the intelligent power distribution terminal and the priority evaluation weight of the comprehensive score of the branch load of each intelligent power distribution terminal are set respectively;

[0050] According to the set weight and the working condition stable maintenance coefficient of each intelligent power distribution terminal, the priority of all intelligent power distribution terminals is evaluated according to the score.

[0051] Compared with the prior art, the beneficial effects of the present application are:

[0052] The present application, by establishing an incremental power distribution network load management system, a low-frequency low-voltage load shedding system, an accident load limiting and stability system, realizes data interaction through a wireless communication network, thereby strengthening the understanding of the actual situation of the incremental power distribution network load; according to the comparison between the incremental power distribution network load and the preset low-voltage load shedding threshold, in combination with the priority of each intelligent power distribution terminal, the low-voltage load shedding operation is realized on the incremental power distribution network load under the condition that the influence degree on the user is reduced to the minimum, which helps to automatically reduce the load when the frequency or voltage of the incremental power distribution network is abnormal, and ensures the stable operation of the incremental power distribution network; at the same time, a load control scheme is formulated to ensure that power limiting measures are taken when the incremental power distribution network load control is implemented, and the influence on the user is minimized; and the operation risk of the power grid after the energy storage is accessed is evaluated in advance, the safety and stability control strategy optimization analysis after the energy storage is accessed is carried out, and the commercial operation economic evaluation is carried out; the cooperation scheme of new energy under different output modes, energy storage, and regional load at different times is analyzed, the optimal source-grid-load-storage control strategy is proposed, and flexible control of light storage load is realized. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 It is the flow chart of the intelligent inspection method for passenger certificates of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work are within the protection scope of the present application.

[0055] In order to solve the technical problem that, with the access of new energy storage and new energy to the regional power grid, the operation risk of the power grid after the access of the energy storage is difficult to evaluate, and the incremental distribution network load is difficult to accurately control, thereby reducing the technical problem of the existing incremental distribution network load coordination function, please refer to Figure 1 The technical solutions are provided in the embodiments.

[0056] In the embodiments, taking the incremental distribution network as the first batch of incremental distribution network business in the country as an example, four 220kV substations have been built, and the current power load is about 1 million kilowatts. The users in the region are mainly petrochemical enterprises with continuous production, and the load density is large and the load is stable. At the same time, in response to the double carbon target, the incremental distribution network develops new energy project construction, and four 110kV photovoltaic booster stations have been built and put into operation, with a total installed capacity of 285MW on the DC side.

[0057] The incremental distribution network load accurate control method comprises the following steps.

[0058] S1, an incremental distribution network load management system is established, and incremental distribution network load information is obtained and analyzed in real time according to an intelligent distribution terminal, including: the change trend, peak value and valley value of the incremental distribution network load, and the change of the incremental distribution network load is accurately predicted; the following operations need to be performed in advance before accurate prediction, specifically including the following steps:

[0059] A plurality of groups of historical incremental distribution network load information are collected, and the historical incremental distribution network load information is cleaned and normalized to ensure the effectiveness and authenticity of the information data; the plurality of groups of historical incremental distribution network load information are taken as a sample set, and are divided into a plurality of training sets and test sets; specifically, a plurality of groups of incremental distribution network load information of Xuwu new area in the past are collected as sample data, and after preprocessing, the sample set is divided, and the two divided data are taken as a feature set of a training and test incremental distribution network load prediction model, and the incremental distribution network load prediction model is continuously updated and iterated according to the continuously updated incremental distribution network load information, to ensure the accuracy and effectiveness of the incremental distribution network load prediction model.

[0060] The incremental power distribution network load prediction model is constructed, the training set is introduced into the incremental power distribution network load prediction model for training, and the training result is output; then the test set is introduced into the incremental power distribution network load prediction model for testing, and the test result is output; the two results are compared to ensure that the test result is consistent with the training result; then the incremental power distribution network load prediction model is optimized and iterated according to different groups of training sets and test sets to ensure the accuracy of the incremental power distribution network load prediction model warning; specifically, the training set is introduced into the incremental power distribution network load prediction model for training to establish the feature points of the incremental power distribution network load prediction model; then a corresponding test set is introduced into the trained incremental power distribution network load prediction model for testing to verify the accuracy of the incremental power distribution network load prediction model output result; after the test result output by the current incremental power distribution network load prediction model is consistent with the training result, the optimized incremental power distribution network load prediction model is obtained, and then the incremental power distribution network load prediction model is used for accurate prediction of the current incremental power distribution network load change.

[0061] After the incremental power distribution network load prediction model is constructed and trained successfully, the model is put into current use, specifically: after the intelligent power distribution terminal acquires and analyzes the incremental power distribution network load information in real time, the following steps are included:

[0062] The incremental power distribution network load information is cleaned and normalized, the preprocessed incremental power distribution network load information is introduced into the incremental power distribution network load warning model for prediction, the current incremental power distribution network load prediction result is output, and the current incremental power distribution network load prediction result is uploaded to the information interaction platform based on the wireless transmission network for data interaction; specifically, after the current obtained incremental power distribution network load information is preprocessed, it is introduced into the optimized incremental power distribution network load prediction model for prediction processing, and the prediction result is output, so as to obtain the prediction result of the current incremental power distribution network load change, and make corresponding load regulation strategy based on the prediction result.

[0063] S2, establish the priority of each intelligent power distribution terminal, calculate the comprehensive score of all branch loads of the intelligent power distribution terminal according to the total amount of incremental power distribution network load uploaded by the intelligent power distribution terminal, and obtain the priority of each intelligent power distribution terminal according to the score sorting; wherein, the comprehensive score of all branch loads of the intelligent power distribution terminal is calculated, specifically including the following steps:

[0064] The loads in the incremental power distribution network are classified, and the loads are divided into primary loads, secondary loads, tertiary loads, industrial loads, commercial loads and residential loads according to the importance of the loads or the power consumption characteristics of the loads; specifically, through the setting of priority, it is helpful to control the incremental power distribution network load, and to preferentially guarantee the key loads such as emergency command and disposal department, radio, television and other users related to safety and social order.

[0065] According to the total capacity of the intelligent power distribution terminal and the operation condition of the intelligent power distribution terminal and the power supply capacity of the power grid, the load is calculated to obtain the load information of each intelligent power distribution terminal, and the priority of each intelligent power distribution terminal is established in combination with the load category to which each intelligent power distribution terminal belongs;

[0066] For example, in the embodiment, the electricity load attribute of Xuwu new district can be divided into industrial load, commercial load and residential load, and further, the regions with more electricity equipment and more densely populated in the industrial load, commercial load and residential load are regarded as the highest load level, the regions with less electricity equipment and less densely populated are regarded as the lowest load level, so that according to the above load priority allocation, when the load control is performed, the load is cut off from the lowest load level first, and the user is affected to the least, so that the incremental power grid load is accurately controlled.

[0067] S3, a low-frequency low-voltage load shedding system is established, and based on the total amount of incremental power grid load uploaded by each intelligent power distribution terminal and the priority of each intelligent power distribution terminal, a low-frequency low-voltage load shedding scheme for incremental power grid load is constructed, recorded and adjusted in advance to realize low-frequency load shedding operation of the incremental power grid load; wherein the low-frequency low-voltage load shedding scheme for incremental power grid load is constructed, recorded and adjusted in advance, specifically including the following steps:

[0068] According to the total amount of incremental power grid load uploaded by the intelligent power distribution terminal, the low-frequency low-voltage load shedding threshold is preset, and it is judged whether the incremental power grid load information is out of the threshold range, if not, no low-frequency load shedding operation is performed; if it is out of the threshold range, in combination with the priority of each intelligent power distribution terminal, it is judged to cut off the load of the intelligent power distribution terminal of a certain load category, based on which the low-frequency low-voltage load shedding scheme for incremental power grid load is formulated to restore the frequency balance of the incremental power grid; wherein the low-frequency low-voltage load shedding scheme for incremental power grid load includes at least three or more; specifically, by configuring the low-frequency low-voltage automatic load shedding function for the intelligent power distribution terminal, it is helpful to automatically reduce the load when the frequency or voltage of the incremental power grid is abnormal, and to ensure the stable operation of the incremental power grid; once it is decided to implement load shedding, the low-frequency low-voltage load shedding system will cut off part of the load according to the predetermined order.

[0069] After the incremental power distribution network load low-frequency low-voltage load shedding scheme is formulated, the incremental power distribution network load low-frequency low-voltage load shedding scheme is input into the low-frequency low-voltage load shedding system through the man-machine module belonging to the low-frequency low-voltage load shedding system, and the incremental power distribution network load low-frequency low-voltage load shedding scheme is preformed, and the deficiencies of the scheme are adjusted in time according to the preformed results to avoid power grid operation errors; specifically, the operator formulates and evaluates the load shedding scheme according to the real-time data of the incremental power distribution network, evaluates the feasibility and risk of the scheme through simulation operation, and avoids power grid misoperation; by putting the preformed power distribution network load low-frequency low-voltage load shedding scheme into use, the operation load of the incremental power distribution network can be effectively reduced, so that the generator and other equipment in the incremental power distribution network are no longer overloaded, and the normal operation of the power generation equipment is protected; when the frequency returns to normal, the device automatically releases the low-frequency load shedding operation, and restores the normal operation of the power system.

[0070] The total amount of incremental power distribution network load at each level is calculated through the incremental power distribution network load real-time data uploaded by each intelligent power distribution terminal, the incremental power distribution network load low-frequency low-voltage load shedding scheme input is selected according to the current incremental power distribution network load total amount, a standard low-frequency low-voltage automatic load shedding scheme report is generated, and the automatic load shedding function belonging to the low-frequency low-voltage load shedding system is controlled to control a part of load equipment in the incremental power distribution network to be switched on or off, so as to realize the low-frequency load shedding operation of the incremental power distribution network; specifically, by generating a standard low-frequency low-voltage automatic load shedding scheme report, complex power grid data can be converted into an intuitive report form, which is convenient for operators to analyze and make decisions, avoids power grid misoperation, reduces the workload of automatic maintenance, and ensures the stable operation of the power system.

[0071] For example, when the frequency of the incremental power distribution network load is detected to be lower than the set threshold in the embodiment, the load shedding link will automatically start, and a part of the secondary load in the incremental power distribution network load, such as the lowest level load in the commercial load, is cut off to reduce the active deficiency of the incremental power distribution network load, so that the operating frequency of the incremental power distribution network load is stabilized within the normal range. It should be noted that the selection of the cut-off load is based on its importance to the incremental power distribution network load and the degree of influence on the entire power grid system; the cut-off load can be a secondary load or a non-critical load. At the same time, in order to ensure the accuracy and effectiveness of the load shedding measures, the low-frequency low-voltage load shedding system will set a certain time delay to distinguish other faults that may cause frequency fluctuations; the time delay is usually between 0.2 and 0.5 seconds to ensure the accurate implementation of the measures; after the basic load shedding measures are implemented, if the frequency of the incremental power distribution network load has not recovered to the normal range, the backup load shedding measures will be triggered to further cut off part of the load to ensure the stability of the frequency of the incremental power distribution network load; after the load shedding measures are taken, the low-frequency low-voltage load shedding system will take measures to gradually restore the cut-off load, and monitor the frequency of the incremental power distribution network load to ensure that it returns to the allowable operating level.

[0072] S4, establish an incident power limiting and new energy grid-connection safety and stability control system, formulate a load control scheme through the incident power limiting sub-system to ensure that when implementing incremental distribution network load control, take power limiting measures to minimize the impact on users; also through the mutual cooperation of the stability control master station, stability control sub-station and terminal station in the new energy grid-connection safety and stability control sub-system, incorporate controllable loads of energy storage, photovoltaic power stations and various substations into the control master station to achieve flexible and precise load control; wherein the stability control master station in the new energy grid-connection safety and stability control sub-system is located in a hub substation or power plant, responsible for aggregating information, forming control strategies and sending control commands; the stability control sub-station is located in an important substation or power plant, responsible for collecting information and sending it to the master station, and the terminal station executes control commands and feeds back; specifically, the incident power limiting and new energy grid-connection safety and stability control system is composed of an incident power limiting sub-system and a new energy grid-connection safety and stability control sub-system, in the power system, when a sudden accident or emergency occurs, in order to protect the stability of the incremental distribution network frequency and voltage, power limiting measures may be taken; for example: when the incremental distribution network loses effective power supply, in order to maintain the stability of the incremental distribution network frequency, low-frequency load shedding can remove the industrial load, commercial load, and residential load in areas with less electrical equipment and sparse population, in order to avoid the collapse of the incremental distribution network and protect the stable operation of the power system; the new energy grid-connection safety and stability control sub-system: this system is mainly composed of a master station, a sub-station and a terminal station, the master station is usually located in a hub substation or a power plant in the same location as the hub substation, responsible for aggregating the operating condition information of each sub-station, estimating the state of the regional power grid, identifying the operating mode of the regional power grid, and forming a safety and stability control strategy table online; the sub-station is installed in an important substation or a power plant associated with the substation, responsible for collecting sub-station operating condition information and transmitting it to the master station; the terminal station receives control commands from each station, executes local control, and transmits control result information to the upper station; through real-time monitoring and rapid response, ensure the stability and safety of new energy grid-connection.

[0073] S5, establish a photovoltaic energy storage load coordination control system, evaluate the operation risk of the power grid after the access of energy storage in advance, develop safety and stability control strategy optimization analysis and commercial operation economic evaluation after the access of energy storage; analyze the coordination scheme of new energy under different output modes, energy storage, regional load at different times, and propose the optimal source-grid-load-storage control strategy to realize photovoltaic energy storage load flexible control; wherein the photovoltaic energy storage load coordination control system is established, specifically including the following steps:

[0074] The energy storage control model and the new energy access model are constructed, the information of the energy storage, the photovoltaic power station and the controllable load of each transformer substation included in the control master station is introduced into the energy storage control model and the new energy access model for rehearsal, the transient security and stability characteristics of the power grid are analyzed, the operation risk of the power grid after the energy storage is accessed is evaluated in advance, and the safety and stability control strategy of the power grid is optimized according to the analysis result; specifically, the accessed energy storage is regulated and controlled by following the steps; 1) function pre-control: at the daily photovoltaic output minimum time, considering the second day photovoltaic predicted output size and load plan, within the limit allowed range of the Nai Chaohe main transformer and the 110kV deep Su7WA line, the energy storage is charged and discharged to preset the charging or discharging state to meet the second day maximum needs, so as to meet the load demand and the maximum consumption demand of new energy; 2) real-time control: when the main transformer or the line is overloaded, or the photovoltaic power generation exceeds the expectation, the energy storage and the new energy are controlled in real time to ensure the safety of the equipment and maximize the consumption of new energy.

[0075] S6, an information interaction platform is established, the incremental distribution network load management system, the intelligent distribution terminal, the low-frequency low-voltage load shedding system and the safety and stability control system of the accident power limiting and new energy grid connection are connected through the wireless transmission network as a transmission medium, data interaction is carried out among the systems in the information interaction platform, the data interface among the systems is developed to realize linkage, and the incremental distribution network load control strategy is optimized.

[0076] Specifically, through the above analysis work, the voltage, frequency and power angle safety and stability characteristics of the power grid after the energy storage is accessed are analyzed, the operation risk of the power grid after the energy storage is accessed is evaluated in advance; the safety and stability control strategy optimization analysis after the energy storage is accessed and the commercial operation economic evaluation are carried out; the cooperation scheme of new energy under different output modes with energy storage and park load at different time periods is analyzed, the optimal source network load storage control strategy is proposed, and the foundation for green and low-carbon operation of the region is laid; finally, the light storage load coordination control system is constructed, and the light storage load flexible control is realized.

[0077] The above-mentioned scheme has the beneficial effects: through the above operation, the incremental distribution network load management system, the low-frequency low-voltage load shedding system, the safety and stability control system of the accident power limiting and new energy grid connection are mutually matched, the existing system is optimized, the data interface among the systems is developed to realize linkage, the control strategy is optimized, the energy storage, the photovoltaic power station and the controllable load of each transformer substation are included in the control master station, and the load flexibility and precise control are realized.

[0078] Working principle: By comparing the incremental distribution network load with the low-voltage load shedding threshold, and combining the priority of each intelligent distribution terminal, the load is subjected to low-voltage load shedding operation, which helps to automatically reduce the load of the distribution network when the frequency or voltage is abnormal, and ensures the stable operation of the incremental distribution network; formulating a load control scheme to ensure that power limiting measures are taken when implementing incremental distribution network load control, thereby minimizing the impact on users; and evaluating the operation risk of the power grid after the energy storage is connected, analyzing the cooperation scheme of new energy under different output modes, energy storage, and regional load at different times, and proposing the optimal source-grid-load-storage control strategy to realize flexible control of light and energy storage.

[0079] Further, the comprehensive score of all branch loads of the intelligent distribution terminal is calculated, including:

[0080] Obtain the load change curve of each branch load of the intelligent distribution terminal, and determine the power consumption peak period parameter and power consumption valley period parameter of each branch load according to the load change curve;

[0081] Obtain a plurality of power consumption indicators of each branch load under the power consumption peak period parameter and the power consumption valley period parameter, respectively;

[0082] Determine the power consumption subject according to the power consumption indicators, determine the load source characteristics based on the power consumption subject, and determine the strong correlation characteristics of each branch load according to the load source characteristics;

[0083] Obtain the modification attribute of the strong correlation characteristics, determine the modification subject of the modification attribute, and the modification subject includes: natural and artificial;

[0084] Determine the peak shaving potential value or valley flattening potential value of the strong correlation characteristics according to the modification subject;

[0085] Determine the load changeable interval of each branch load according to the peak shaving potential value or valley flattening potential value, and determine the load adjustment score of each branch load according to the load changeable interval;

[0086] Extract the effective static response load and the effective dynamic response load of each branch load, respectively, and determine the demand response settlement score of each branch load according to the effective static response load and the effective dynamic response load;

[0087] Determine the load supply score of each branch load according to the demand response settlement score;

[0088] Obtain the power grid topology of each branch load, determine the load loss factor according to the power grid topology, and determine the load loss proportion of each branch load according to the load loss factor, power grid data, and preset power grid utilization efficiency evaluation index;

[0089] The load loss score of each branch load is determined according to the load loss proportion, and the comprehensive score of all branch loads of the intelligent power distribution terminal is calculated according to the load loss score, the load supply score and the load adjustment score and preset weights of the three.

[0090] The beneficial effects of the above technical solutions are that: by determining the multi-dimensional load score of each branch load and then calculating the comprehensive score, the comprehensive score evaluation can be performed on multiple parameters such as load use, loss and adjustment of each branch load to ensure comprehensive evaluation of each branch load.

[0091] Further, before the priority of each intelligent power distribution terminal is obtained according to the score ranking, the following steps are further included:

[0092] Obtain the working condition parameter change of each intelligent power distribution terminal during the operation of the branch load, and construct a working condition disturbance linearization matrix of each intelligent power distribution terminal according to the working condition parameter change;

[0093] Obtain the minimum eigenvalue of each intelligent power distribution terminal under the current working condition according to the working condition disturbance linearization matrix;

[0094] Obtain the minimum eigenvalue of each intelligent power distribution terminal under the standard working condition, and calculate the working condition stable maintenance coefficient of each intelligent power distribution terminal according to the minimum eigenvalue of each intelligent power distribution terminal under the current working condition and the minimum eigenvalue of each intelligent power distribution terminal under the standard working condition:

[0095]

[0096] Wherein, S i represents the working condition stable maintenance coefficient of the i th intelligent power distribution terminal, μ represents the linear load limit super parameter, D 1i represents the minimum eigenvalue of the i th intelligent power distribution terminal under the current working condition, D 2i represents the minimum eigenvalue of the i th intelligent power distribution terminal under the standard working condition, A i represents the maintenance coefficient of the i th intelligent power distribution terminal, α represents the influence factor of the working condition stable margin of the intelligent power distribution terminal affected by the fluctuation degree of the load state variable, F i represents the number of branch loads of the i th intelligent power distribution terminal, j represents the j th branch load, Q 1j represents the maximum load of the j th branch load, Q 2j represents the minimum load of the i th branch load;

[0097] The priority evaluation weight of the working condition stable maintenance coefficient of the intelligent power distribution terminal and the priority evaluation weight of the comprehensive score of each branch load of the intelligent power distribution terminal are set respectively;

[0098] According to the setting weight, the working condition stable maintenance coefficient of each intelligent power distribution terminal and the score ranking, priority of all intelligent power distribution terminals is evaluated.

[0099] The above technical solution has the beneficial effects that: by calculating the working condition stable maintenance coefficient of each intelligent power distribution terminal and then according to the comprehensive score of the working condition performance and branch load of the intelligent power distribution terminal, the priority of the intelligent power distribution terminal is evaluated in multiple dimensions, which guarantees the objectivity and reliability of the evaluation result and improves the practicability.

[0100] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0101] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, alternatives, and variations can be made thereto without departing from the principles and spirit of the application.

Claims

1. A method for precise load control in incremental distribution networks, characterized in that, Includes the following steps: S1. Establish an incremental distribution network load management system, and accurately predict the load changes of the incremental distribution network by acquiring and analyzing the load information of the incremental distribution network in real time based on the intelligent distribution terminal, including the load change trend, peak value and valley value of the incremental distribution network. S2. Establish the priority of each smart distribution terminal. Based on the total incremental distribution network load of each level uploaded by the smart distribution terminal, calculate the comprehensive score of the load of all branches of the smart distribution terminal, and obtain the priority of each smart distribution terminal according to the score. Before prioritizing each smart power distribution terminal based on its score, the following steps are also included: Obtain the changes in operating parameters of each smart distribution terminal when the branch load is working, and construct the linearization matrix of operating disturbance of each smart distribution terminal based on the changes in operating parameters; The minimum eigenvalue of each smart power distribution terminal under the current operating condition is obtained based on the linearization matrix of the operating condition disturbance. Obtain the minimum eigenvalue of each smart power distribution terminal under standard operating conditions, and calculate the operating condition stability maintenance coefficient of each smart power distribution terminal based on the minimum eigenvalue of each smart power distribution terminal under the current operating conditions and the minimum eigenvalue of each smart power distribution terminal under standard operating conditions. Set priority evaluation weights for the operating condition stability maintenance coefficient of the intelligent power distribution terminal and for the comprehensive score of the branch load of each intelligent power distribution terminal. All smart distribution terminals are prioritized based on their assigned weights, the stability maintenance coefficient of each smart distribution terminal, and their scores. S3. Establish a low-frequency, low-voltage load shedding system. Based on the total load of each level of the incremental distribution network uploaded by the intelligent distribution terminals and the priority of each intelligent distribution terminal, pre-build, input, and adjust the low-frequency, low-voltage load shedding scheme for the incremental distribution network to achieve low-frequency load shedding operations on the incremental distribution network. S4. Establish a power curtailment and renewable energy grid connection safety and stability control system. Through the power curtailment system, formulate load control plans to ensure that power curtailment measures are taken when implementing incremental distribution network load control, minimizing the impact on users. Furthermore, through the cooperation of the main control station, sub-control stations, and terminal stations in the renewable energy grid connection safety and stability control subsystem, incorporate the controllable loads of energy storage, photovoltaic power stations, and various substations into the main control station to achieve flexible and precise load control. S5. Establish a photovoltaic-storage-load coordinated control system to conduct advance assessments of grid operation risks after energy storage is connected, carry out optimization analysis of safety and stability control strategies after energy storage is connected, and conduct economic assessments of commercial operation; analyze the coordination schemes of new energy with energy storage and regional loads at different time periods under different output modes, propose the optimal source-grid-load-storage control strategy, and realize flexible control of photovoltaic-storage-load.

2. The incremental distribution network load precision control method according to claim 1, characterized in that: The operating condition stability maintenance coefficient of each smart power distribution terminal is calculated in S2, and the calculation formula is as follows: ； in, Let represent the operating condition stability maintenance coefficient of the i-th intelligent power distribution terminal. This is expressed as the linear load limit hyperparameter. Let be the minimum eigenvalue of the i-th intelligent power distribution terminal under the current operating conditions. Let be the minimum eigenvalue of the i-th intelligent power distribution terminal under standard operating conditions. Let represent the maintenance coefficient of the i-th intelligent power distribution terminal. This represents the influence factor on the stability margin of the intelligent power distribution terminal due to the degree of fluctuation in load state variables. Let represent the number of branch loads of the i-th smart distribution terminal, and j represent the number of branch loads of the j-th branch. This represents the maximum load of the j-th branch. This represents the minimum load of the i-th branch.

3. The method for precise control of incremental distribution network load according to claim 1, characterized in that: It also includes the following steps: S6. Establish an information exchange platform. Using a wireless transmission network as the transmission medium, enable data exchange between the incremental distribution network load management system, intelligent distribution terminal, low-frequency and low-voltage load shedding system, and emergency power curtailment and new energy grid connection safety and stability control system. This will ensure that data interfaces are developed between the systems to achieve linkage and optimize the incremental distribution network load control strategy.

4. The method for precise control of incremental distribution network load according to claim 1, characterized in that: After establishing the incremental distribution network load management system in S1, the following steps are included: Collect multiple sets of historical incremental distribution network load information, clean and normalize the historical incremental distribution network load information; use multiple sets of historical incremental distribution network load information as a sample set, and divide it into multiple training sets and test sets; An incremental distribution network load forecasting model is constructed. The training set is imported into the incremental distribution network load forecasting model for training, and the training results are output. Then, the test set is imported into the incremental distribution network load forecasting model for testing, and the test results are output. The two results are compared to ensure that the test results are consistent with the training results. Then, the incremental distribution network load forecasting model is optimized and iterated based on different training sets and test sets to ensure the accuracy of the early warning of the incremental distribution network load forecasting model.

5. The method for precise control of incremental distribution network load according to claim 4, characterized in that: The step S1, after acquiring and analyzing the incremental distribution network load information in real time based on the intelligent distribution terminal, includes the following steps: The incremental distribution network load information is cleaned and normalized. The pre-processed incremental distribution network load information is then imported into the incremental distribution network load early warning model for prediction. The current incremental distribution network load prediction result is then output and uploaded to the information exchange platform for data exchange via a wireless transmission network.

6. The method for precise control of incremental distribution network load according to claim 1, characterized in that: The calculation of the comprehensive score of all branch loads of the intelligent power distribution terminal in S2 specifically includes the following steps: The loads in the incremental distribution network are classified according to their importance or electricity consumption characteristics into primary loads, secondary loads, tertiary loads, or industrial loads, commercial loads, and residential loads. Based on the total incremental distribution network load of each level uploaded by each smart distribution terminal, the load is calculated according to the total capacity of the smart distribution terminals, their operating status, and the power supply capacity of the power grid. The load information of each smart distribution terminal is obtained, and the priority of each smart distribution terminal is determined by combining the load category to which each smart distribution terminal belongs.

7. The method for precise control of incremental distribution network load according to claim 1, characterized in that: The pre-constructed, input, and adjusted incremental distribution network load low-frequency and low-voltage load shedding scheme in S3 specifically includes the following steps: Based on the total load of each level of incremental distribution network uploaded by the smart distribution terminal, a low-frequency and low-voltage load shedding threshold is preset. It is then determined whether the incremental distribution network load information exceeds the threshold range. If it does not exceed the threshold range, no low-frequency load shedding operation is performed. If it exceeds the threshold range, the load of a certain load category of smart distribution terminal is determined and the priority of each smart distribution terminal is considered. Based on this, an incremental distribution network load low-frequency and low-voltage load shedding scheme is formulated to restore the frequency balance of the incremental distribution network. The incremental distribution network load low-frequency and low-voltage load shedding scheme includes at least three or more types.

8. The method for precise control of incremental distribution network load according to claim 7, characterized in that: The pre-constructed, input, and adjusted incremental distribution network load low-frequency and low-voltage load shedding scheme in S3 also includes the following steps: After formulating the low-frequency and low-voltage load shedding scheme for the incremental distribution network, the scheme is entered into the low-frequency and low-voltage load shedding system through the human-machine module of the system. The scheme is then rehearsed, and any deficiencies are adjusted in a timely manner based on the rehearsal results to avoid errors in grid operation. After pre-constructing, inputting, and adjusting the incremental distribution network load low-frequency and low-voltage load shedding scheme in S3, the following steps are included: The total load of each level of incremental distribution network is calculated by using real-time load data uploaded by each intelligent distribution terminal. Based on the current total load of the incremental distribution network, the low-frequency and low-voltage load shedding schemes of the recorded incremental distribution network loads are judged and selected. A standard report on low-frequency and low-voltage automatic load shedding schemes is generated. The automatic load shedding function of the low-frequency and low-voltage load shedding system is controlled to switch on or off some load equipment in the incremental distribution network, thereby realizing the low-frequency load shedding operation of the incremental distribution network.

9. The method for precise control of incremental distribution network load according to claim 1, characterized in that: In the S4 new energy grid connection safety and stability control subsystem, the stability control master station is located in the hub substation or power plant and is responsible for summarizing information, forming control strategies and sending control commands; the stability control substation is located in the important substation or power plant and is responsible for collecting information and sending it to the master station; the terminal station executes the control commands and provides feedback. Through real-time monitoring and control, the stability and safety of new energy power generation during grid connection are ensured. The photovoltaic-storage-load coordination control system established in S5 specifically includes the following steps: An energy storage control model and a new energy access model are constructed. The controllable load information of energy storage, photovoltaic power stations and various substations included in the control master station is imported into the energy storage control model and the new energy access model for drills. The transient safety and stability characteristics of the power grid are analyzed, the operational risks of the power grid after the energy storage is connected are assessed in advance, and the power grid safety and stability control strategy is optimized based on the analysis results.

10. The method for precise control of incremental distribution network load according to claim 1, characterized in that: Calculate the overall score of all branch loads in the intelligent distribution terminal, including: Obtain the load change curve of each branch load of the intelligent power distribution terminal, and determine the peak power consumption period parameters and valley power consumption period parameters of each branch load based on the load change curve; Multiple electricity consumption indicators for each branch load are obtained under peak electricity consumption period parameters and off-peak electricity consumption period parameters; The electricity users are identified based on electricity consumption indicators, the load source characteristics are determined based on the electricity users, and the strong correlation characteristics of the load of each branch are determined based on the load source characteristics. Obtain the modified attributes of strongly correlated features, and determine the subject of modification of the modified attributes, wherein the subject of modification includes: natural and human; The peak-shaving potential value or valley-flattening potential value of strongly correlated features is determined based on the subject of modification. The load variation range of each branch load is determined based on the peak shaving potential value or valley potential value, and the load regulation score of each branch load is determined based on the load variation range. Extract the effective static response load and effective dynamic response load of each branch load separately, and determine the demand response settlement score of each branch load based on the effective static response load and effective dynamic response load; The load supply score for each branch load is determined based on the demand response settlement score; Obtain the power grid topology of each branch load, determine the load loss factor based on the power grid topology, and determine the load loss ratio of each branch load based on the load loss factor, power grid data, and preset power grid utilization efficiency evaluation indicators. The load loss score for each branch load is determined based on the load loss ratio. The comprehensive score of all branch loads in the intelligent power distribution terminal is calculated based on the load loss score, load supply score, and load regulation score, as well as their respective preset weights.

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