A new energy station dynamic reactive power reserve target allocation method and system considering power fluctuation

Abstract

The application discloses a new energy station dynamic reactive power reserve target distribution method and system considering power fluctuation, relates to the field of power system automation technology, and comprises the following steps: a dispatch master station AVC statistical area dynamic reactive power reserve quantity is counted, a regional dynamic reactive power reserve target value is obtained through optimization calculation, and dynamic reactive power reserve target upper and lower limit values distributed to new energy stations are calculated according to a set distribution principle; the AVC master station evaluates voltage probability intervals caused by power fluctuation through prediction information, corrects the dynamic reactive power reserve target upper and lower limit values of the new energy stations, optimizes dynamic reactive power reserve distribution, and issues the dynamic reactive power reserve target upper and lower limit values to AVC sub-stations of the new energy stations for reactive power regulation. The application retains reasonable dynamic reactive power reserve, improves the ability of each new energy station to cope with power fluctuation and other disturbance abnormal conditions, and realizes stable grid-connected power generation and safe consumption of new energy.

Description

Technical Field

[0001] This invention relates to the field of power system automation technology, and in particular to a method and system for dynamic reactive power reserve target allocation of new energy power plants that takes into account power fluctuations. Background Technology

[0002] In recent years, the installed capacity of new energy sources has been continuously increasing, and the proportion of new energy output in the total grid load has been rising year by year. This high proportion of new energy has impacted the voltage support capacity of the power grid, and significant fluctuations in output have led to difficulties in grid voltage adjustment, resulting in prominent voltage problems in some areas. The amount of reactive power reserves is strongly correlated with the system's safety and stability; therefore, optimizing them is a crucial means to ensure the safety and stability of the power system. By rationally and fully utilizing various types of reactive power regulation resources, reasonable dynamic reactive power reserves can be maintained at each new energy power station globally to cope with power fluctuations and other disturbances, thereby improving the system's voltage safety margin and achieving stable grid-connected power generation from new energy sources. This, in turn, improves the grid's dispatching capabilities for intermittent new energy sources, enhances the grid's capacity to accommodate large-scale new energy sources, and ensures stable grid-connected power generation and stable power transmission from new energy areas under disturbances.

[0003] The dispatching master station uses AVC analysis to determine the target value of dynamic reactive power reserve within its control area. This target value is then allocated to each renewable energy power station within the area, ensuring that the total dynamic reactive power reserve meets safety constraints. However, due to uncertainties such as large fluctuations in renewable energy generation, the allocation of the dynamic reactive power reserve target value may be insufficient in the future, potentially reducing the safe and stable operation of the renewable energy power stations. Current technologies for dynamic reactive power reserve allocation at renewable energy power stations are typically based on static or simple dynamic models, failing to fully consider the dynamic response requirements of the power grid caused by power fluctuations. This may result in ineffective voltage stability regulation under grid disturbance conditions. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by this invention is: how to provide a reasonable reactive power allocation method to improve the ability of various new energy regions to cope with various disturbance and abnormal situations.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, embodiments of the present invention provide a method for allocating dynamic reactive power reserve targets for new energy power plants that considers power fluctuations, including:

[0008] By reporting in real time from new energy power stations, the maximum adjustable amount of reactive power of each power station within the control area can be obtained.

[0009] The target voltage value of the high-voltage side bus of each new energy power station is calculated by the regional two-level voltage optimization decision method and used as the voltage optimization target value of each new energy power station.

[0010] Based on the reactive power margin method of static voltage safety domain, the upper and lower limits of the dynamic reactive power reserve target for each new energy power station in the region are calculated.

[0011] Based on the ultra-short-term forecast information of new energy sources provided by external systems, assess the extreme values ​​of power output of each new energy source and the extreme values ​​of power output of new energy sources in the region within the next four hours.

[0012] Based on the power flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, the power flow of the grid under the two sections of the highest and lowest extreme values ​​of regional new energy output is calculated, and the probability interval of the voltage level of new energy power stations is evaluated.

[0013] Based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, the upper and lower limits of the reactive power reserve target of each station are adjusted according to the voltage probability range of each new energy station.

[0014] The revised upper and lower limits of reactive power reserve targets for each power station are issued to the automatic voltage control system substations of the new energy power stations, and the substations execute them within the stations.

[0015] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0016] The control area is an automatic voltage control area formed by automatic partitioning of the main station's automatic voltage control system, characterized by strong reactive voltage coupling within the area and weak coupling between areas.

[0017] The maximum adjustable reactive power capacity of each power station is the reactive power adjustable capacity reported by each renewable energy power station to the main station in real time, which is divided into maximum upward reactive power adjustment. and maximum reactive power downward adjustment Where j is the number of each new energy power station in the region.

[0018] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0019] The upper and lower limits of the dynamic reactive power reserve target for each new energy power station include the reactive power adjustable reserve margin constraint that each new energy power station needs to maintain, which is divided into the upper limit of the reactive power reserve target. and the lower limit of reactive power reserve target

[0020] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0021] The assessment of the extreme values ​​of power output of each new energy source and the extreme values ​​of regional new energy power output in the next four hours includes:

[0022] The maximum and minimum active power output of each renewable energy station in the next four hours are respectively P j max P j min The regional renewable energy output extreme value is the maximum and minimum total active power output of renewable energy in the next four hours, P. max P min .

[0023] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0024] The calculation of power flow at two cross-sections, representing the highest and lowest extreme values ​​of regional renewable energy output, and the assessment of the probability interval for the voltage level of renewable energy power stations, include:

[0025] The voltage levels V of each renewable energy node under the two extreme value sections were calculated by power flow calculation. j max V j min Assess the voltage probability range [V] of new energy power stations j dn V j up Specifically:

[0026] The voltage fluctuation probability impact factor of renewable energy power plants is calculated based on the highest and lowest total renewable energy output in the region, and corrected for the short-term extreme output changes of each renewable energy plant. This correction factor includes the voltage fluctuation impact factor. Influence factors of voltage fluctuation Represented as:

[0027]

[0028]

[0029] Among them, P j up P j dn The active power output of each new energy power station under the two extreme cross sections of the highest and lowest contribution to regional new energy;

[0030] The voltage probability interval for renewable energy power plants is calculated and expressed as:

[0031]

[0032]

[0033] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0034] The process of adjusting the upper and lower limits of the reactive power reserve target for each renewable energy station based on the voltage probability range of each station includes:

[0035] Calculate the reactive power reserve demand correction for each renewable energy station within the voltage fluctuation probability range, divided into reactive power upward regulation demand correction. Demand correction under reactive power regulation Represented as:

[0036]

[0037]

[0038] Where s j Let be the sensitivity of the voltage at the j-th renewable energy power station node to the reactive power of this node. These are the upper and lower voltage limits for each new energy power station.

[0039] As a preferred scheme for the dynamic reactive power reserve target allocation method of new energy power plants considering power fluctuations, the following is provided:

[0040] The method of adjusting the upper and lower limits of the reactive power reserve target for each renewable energy station based on the voltage probability range of each station also includes:

[0041] The reactive power reserve target for each renewable energy station within the correction area is calculated by adding the demand adjustment amount to the upper and lower limits of the dynamic reactive power reserve target, as follows:

[0042]

[0043] The revised reactive power reserve target is compared with the maximum adjustable reactive power of new energy power plants. After correction, the final reactive power reserve target value for each new energy station is obtained, expressed as:

[0044]

[0045] Secondly, embodiments of the present invention provide a dynamic reactive power reserve target allocation system for new energy power plants that considers power fluctuations, comprising:

[0046] The adjustable quantity acquisition module is used to obtain the maximum vertical and horizontal adjustable quantity of reactive power of each station within the control area through real-time reporting from the new energy power stations.

[0047] The high-voltage side bus voltage target value calculation module is used to calculate the high-voltage side bus voltage target value of each new energy power station through the regional two-level voltage optimization decision method, and serve as the voltage optimization target value of each new energy power station;

[0048] The dynamic reactive power reserve target upper and lower limit calculation module is used to calculate the dynamic reactive power reserve target upper and lower limits for each new energy power station in the region based on the reactive power margin method of static voltage safety domain.

[0049] The extreme value calculation module is used to evaluate the extreme values ​​of each new energy source output and the extreme values ​​of regional new energy output based on the ultra-short-term forecast information of new energy sources provided by external systems in the next four hours.

[0050] The evaluation module is used to calculate the power flow under the two sections of the highest and lowest extreme values ​​of regional new energy output based on the power flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, and to evaluate the probability interval of the voltage level of new energy power stations.

[0051] The correction module is used to correct the upper and lower limits of the reactive power reserve target for each renewable energy station based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, according to the voltage probability range of each station.

[0052] The execution module is used to send the revised upper and lower limits of reactive power reserve targets for each power station to the automatic voltage control system substation of the new energy power station, and the substation performs the execution within the station.

[0053] Thirdly, embodiments of the present invention provide a computing device, including:

[0054] Memory and processor;

[0055] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the one or more programs are executed by the one or more processors, the one or more processors implement the dynamic reactive power reserve target allocation method for new energy power plants that takes power fluctuations into account, as described in any embodiment of the present invention.

[0056] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the aforementioned method for allocating dynamic reactive power reserve targets for new energy power plants considering power fluctuations.

[0057] The beneficial effects of this invention are as follows: This invention considers the impact of power changes in new energy power plants on bus voltage in the short term, assesses the voltage probability range, corrects the reactive power reserve target, reserves the necessary reactive power reserve requirements in advance, and optimizes the reactive power distribution of new energy power plants to better support voltage quality assurance under power fluctuations; it requires less modification to the operating system, making it easier to implement; it retains reasonable dynamic reactive power reserves, improves the ability of each new energy power plant to cope with abnormal situations such as power fluctuations, and realizes stable grid connection and safe consumption of new energy. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is an overall flowchart of the dynamic reactive power reserve target allocation method for new energy power plants that takes into account power fluctuations, as described in the first embodiment of the present invention. Detailed Implementation

[0060] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0061] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0062] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0063] Example 1

[0064] Reference Figure 1This is the first embodiment of the present invention, which provides a method for allocating dynamic reactive power reserve targets for new energy power plants that takes into account power fluctuations, including:

[0065] S1: By reporting in real time from the new energy power stations, the maximum adjustable amount of reactive power of each power station within the control area can be obtained.

[0066] In this embodiment of the application, the automatic voltage control system of the dispatch master station obtains the maximum adjustable amount of reactive power of each station in the control area by reporting in real time through the new energy power stations;

[0067] The control area is the automatic voltage control area formed by the automatic zoning of the main station's automatic voltage control system. It is characterized by strong reactive voltage coupling within the area and weak coupling between areas.

[0068] The maximum adjustable reactive power capacity of each power station is the reactive power adjustable capacity reported by each renewable energy power station to the main station in real time, which is divided into maximum upward reactive power adjustment. and maximum reactive power downward adjustment Where j is the number of each new energy power station in the region.

[0069] S2: The target voltage value of the high-voltage side bus of each new energy power station is calculated by the regional secondary voltage optimization decision method and used as the voltage optimization target value of each new energy power station;

[0070] It should be noted that the automatic voltage control system of the dispatching master station calculates the target voltage value of the high-voltage bus for each renewable energy power station through a regional two-level voltage optimization decision-making method. With a clear target voltage value for the high-voltage bus, each renewable energy power station can more precisely adjust its output power, thereby stabilizing the grid voltage, reducing voltage fluctuations, and improving the voltage quality and stability of the grid. Setting a voltage optimization target value helps maintain a stable voltage level under different operating conditions, reducing the operational risks caused by voltage anomalies and improving the reliability and security of the power system. Each power station can adjust its own operating strategy according to the set voltage optimization target value to maximize the utilization of available power resources and improve power generation efficiency and economy. Through precise allocation of voltage optimization target values, more renewable energy power stations can be effectively connected to the grid, improving the grid's carrying capacity and stability, and promoting the large-scale application and consumption of clean energy.

[0071] S3: Based on the reactive power margin method of static voltage safety domain, calculate the upper and lower limits of the dynamic reactive power reserve target for each new energy power station in the region;

[0072] In this embodiment, the automatic voltage control system of the dispatch master station calculates the upper and lower limits of the dynamic reactive power reserve target for each new energy power station within the region based on the reactive power margin method of the static voltage safety domain. The upper and lower limits of the dynamic reactive power reserve target for each new energy power station include the reactive power adjustable reserve margin constraint that each new energy station needs to retain, which is divided into the upper limit of the reactive power reserve target. and the lower limit of reactive power reserve target

[0073] S4: Based on the ultra-short-term forecast information of new energy sources provided by external systems, assess the extreme values ​​of the output of each new energy source and the extreme values ​​of the regional new energy output in the next four hours.

[0074] In this embodiment of the application, the evaluation of the extreme values ​​of power output of each new energy source and the extreme values ​​of power output of the regional new energy source within the next four hours includes:

[0075] The maximum and minimum active power output of each renewable energy station in the next four hours are respectively P j max P j min The regional renewable energy output extreme value is the maximum and minimum total active power output of renewable energy in the next four hours, P. max P min .

[0076] S5: Based on the power grid flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, calculate the power grid flow under the two sections of the highest and lowest extreme values ​​of regional new energy output, and evaluate the probability interval of the voltage level of new energy power stations.

[0077] In this embodiment of the application, the power flow is calculated at two cross-sections, namely the highest and lowest extreme values ​​of regional renewable energy output, and the probability interval of the voltage level of renewable energy power stations is evaluated, including:

[0078] The voltage levels V of each renewable energy node under the two extreme value sections were calculated by power flow calculation. j max V j min Assess the voltage probability range [V] of new energy power stations j dn V j up Specifically:

[0079] The voltage fluctuation probability impact factor of renewable energy power plants is calculated based on the highest and lowest total renewable energy output in the region, and corrected for the short-term extreme output changes of each renewable energy plant. This correction factor includes the voltage fluctuation impact factor. Influence factors of voltage fluctuation Represented as:

[0080]

[0081]

[0082] Among them, P j up P j dn The active power output of each new energy power station under the two extreme cross sections of the highest and lowest contribution to regional new energy;

[0083] The voltage probability interval for renewable energy power plants is calculated and expressed as:

[0084]

[0085]

[0086] S6: Based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, adjust the upper and lower limits of the reactive power reserve target of each station according to the voltage probability range of each new energy station.

[0087] In this embodiment of the application, the adjustment of the upper and lower limits of the reactive power reserve target for each renewable energy station based on the voltage probability range of each station includes:

[0088] Calculate the reactive power reserve demand correction for each renewable energy station within the voltage fluctuation probability range, divided into reactive power upward regulation demand correction. Demand correction under reactive power regulation Represented as:

[0089]

[0090]

[0091] Where s j Let be the sensitivity of the voltage at the j-th renewable energy power station node to the reactive power of this node. These are the upper and lower voltage limits for each new energy power station.

[0092] The reactive power reserve target for each renewable energy station within the correction area is calculated by adding the demand adjustment amount to the upper and lower limits of the dynamic reactive power reserve target, as follows:

[0093]

[0094]

[0095] The revised reactive power reserve target is compared with the maximum adjustable reactive power of new energy power plants. After correction, the final reactive power reserve target value for each new energy station is obtained, expressed as:

[0096]

[0097] S7: The revised upper and lower limits of reactive power reserve targets for each power station are sent to the automatic voltage control system substations of the new energy power stations, and the substations execute them within the stations.

[0098] It should be noted that the automatic voltage control system of the dispatch master station distributes the revised upper and lower limits of reactive power reserve targets for each power station to the automatic voltage control system substations of the renewable energy power stations. After distributing these revised targets to the substations, it ensures that each power station accurately controls its reactive power output during actual operation to meet the dynamic demands of the power grid. This helps maintain voltage stability and system operating efficiency during grid disturbances. The execution of the revised reactive power reserve targets within the substations allows for rapid response to changes in grid conditions, such as quickly adjusting reactive power output to cope with sudden load changes or grid faults. This improved response speed helps reduce grid fluctuations and enhances the grid's responsiveness and stability. Local adjustments by each substation based on the revised target values ​​can maximize the optimization of the operating efficiency and energy utilization of renewable energy power stations, thereby improving power generation efficiency and reducing operating costs. By revising and executing these targets at each power station level, the safe and stable operation of the entire power system can be effectively guaranteed, reducing potential risks caused by insufficient or excessive reactive power reserves and ensuring that the power grid operates within safe boundaries.

[0099] The above is an illustrative scheme of the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations in this embodiment. It should be noted that the technical solution of the dynamic reactive power reserve target allocation system for new energy power plants considering power fluctuations and the technical solution of the aforementioned dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations belong to the same concept. Details not described in detail in the technical solution of the dynamic reactive power reserve target allocation system for new energy power plants considering power fluctuations in this embodiment can be found in the description of the aforementioned technical solution of the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations.

[0100] This embodiment of the dynamic reactive power reserve target allocation system for new energy power plants, considering power fluctuations, includes:

[0101] The adjustable quantity acquisition module is used to obtain the maximum vertical and horizontal adjustable quantity of reactive power of each station within the control area through real-time reporting from the new energy power stations.

[0102] The high-voltage side bus voltage target value calculation module is used to calculate the high-voltage side bus voltage target value of each new energy power station through the regional two-level voltage optimization decision method, and serve as the voltage optimization target value of each new energy power station;

[0103] The dynamic reactive power reserve target upper and lower limit calculation module is used to calculate the dynamic reactive power reserve target upper and lower limits for each new energy power station in the region based on the reactive power margin method of static voltage safety domain.

[0104] The extreme value calculation module is used to evaluate the extreme values ​​of each new energy source output and the extreme values ​​of regional new energy output based on the ultra-short-term forecast information of new energy sources provided by external systems in the next four hours.

[0105] The evaluation module is used to calculate the power flow under the two sections of the highest and lowest extreme values ​​of regional new energy output based on the power flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, and to evaluate the probability interval of the voltage level of new energy power stations.

[0106] The correction module is used to correct the upper and lower limits of the reactive power reserve target for each renewable energy station based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, according to the voltage probability range of each station.

[0107] The execution module is used to send the revised upper and lower limits of reactive power reserve targets for each power station to the automatic voltage control system substation of the new energy power station, and the substation performs the execution within the station.

[0108] This embodiment also provides a computing device applicable to the dynamic reactive power reserve target allocation method for new energy power plants that considers power fluctuations, including:

[0109] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the dynamic reactive power reserve target allocation method for new energy power plants that considers power fluctuations, as proposed in the above embodiments.

[0110] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the dynamic reactive power reserve target allocation method for new energy power plants that considers power fluctuations, as proposed in the above embodiments.

[0111] The storage medium proposed in this embodiment and the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0112] Example 2

[0113] Referring to the figure, an embodiment of the present invention is provided, which provides a method for dynamic reactive power reserve target allocation of new energy power plants that takes into account power fluctuations. In order to verify the beneficial effects of the present invention, a simulation experiment is conducted for scientific demonstration.

[0114] Step 1: Based on the power grid topology, the entire power grid is divided into several control areas. Within each area, reactive power and voltage are strongly coupled, while between areas, coupling is weak. The dispatch master station (AVC) obtains the maximum reactive power up-regulation of each renewable energy power station through real-time reports. and maximum reactive power downward adjustment In the formula, j = 1, 2, 3, ..., N represents the j-th new energy field, and the total adjustable reactive power of the region is obtained by summing and statistically analyzing the data. Adjustable amount under total reactive power The calculation formula is:

[0115]

[0116]

[0117] Taking a specific power grid area as an example, there are four renewable energy power stations in this area. The basic data obtained is as follows:

[0118] Table 1 Basic Data of New Energy Power Stations

[0119]

[0120] Step 2: The dispatch master station AVC calculates the target value of the high-voltage side bus voltage of the new energy power station through the regional secondary voltage optimization algorithm.

[0121] Step 3: The dispatch master station AVC calculates the upper and lower limits of the dynamic reactive power reserve target for each renewable energy power station in the region using a conventional static voltage security domain assessment method. This is the reactive power adjustable margin constraint range that each renewable energy station needs to retain, divided into the upper limit of the reactive power reserve target. Lower limit of reactive power reserve target The settlement results are shown in the table below.

[0122] Table 2 Calculation Results of Upper and Lower Limits of Dynamic Reactive Power Reserve Target

[0123]

[0124]

[0125] Step 4: Evaluate the extreme values ​​of power output of each renewable energy source and the regional renewable energy output extreme values ​​within the next four hours using ultra-short-term renewable energy forecast information obtained from external systems, and determine the maximum and minimum active power output P of each renewable energy station within the next four hours. j max P j min The regional renewable energy output extreme value is the maximum and minimum total active power output of renewable energy in the next four hours, P. max P minAnd the active power output P of each new energy power station under the two extreme cross sections. j up P j dn .

[0126] Step 5: Using the power flow calculation method, calculate the power flow at the two extreme sections with the highest and lowest output of new energy sources in the region, and obtain the voltage level V of each new energy node at these two extreme sections. j max V j min Furthermore, based on the highest and lowest total regional renewable energy output, adjustments are made considering the short-term extreme output changes of each renewable energy station, which serve as a voltage fluctuation impact factor, and are divided into voltage fluctuation impact factors. Voltage fluctuation influence factor The calculation formula is as follows:

[0127]

[0128]

[0129] The calculation results are shown in the table below:

[0130] Table 3. Extreme value calculation results

[0131]

[0132] Step 6: Based on the voltage levels of the two extreme cross-sections, and taking into account the voltage fluctuation influence factor, calculate the voltage probability interval [V] of the new energy power station. j dn V j up The formula is as follows:

[0133]

[0134] The obtained voltage probability intervals are shown in the table below:

[0135] Table 4 Voltage Probability Intervals

[0136] G1 116.7 115.5 G2 116.6 115.4 G3 116.8 115.2 G4 115.8 115

[0137] Step 7: Based on the voltage probability range of each renewable energy power station, to correct the risk of voltage exceeding limits and meet the reactive power reserve requirement adjustment for voltage fluctuation probability, calculate the reactive power reserve requirement adjustment amount for each renewable energy station within the voltage fluctuation probability range, divided into reactive power adjustment requirement adjustment amount. Demand correction under reactive power regulation The formula is as follows:

[0138]

[0139]

[0140] Where s j Let be the sensitivity of the voltage at the j-th renewable energy power station node to the reactive power of this node. The voltage upper and lower limits for each new energy power station are set at 114.0kV-116.5kV, i.e.

[0141] Step 8: Based on the initial reactive power reserve target of each renewable energy power station, further revise the reactive power reserve target of each renewable energy power station, using the following formula:

[0142]

[0143]

[0144] The calculation results are shown in the table below:

[0145] Table 5 Revision of Reactive Power Reserve Target

[0146]

[0147]

[0148] Step 9: Compare the revised reactive power reserve target with the maximum adjustable reactive power of the renewable energy power station. After correction, the final reactive power reserve target value for each new energy station is obtained, as shown in the following formula:

[0149]

[0150]

[0151] The revised final reactive power reserve target values ​​for renewable energy stations are as follows:

[0152] Table 6 Final Reactive Power Reserve Target Values ​​for New Energy Stations

[0153]

[0154] Step 11: The dispatch master station AVC sends the target value of the high-voltage side bus voltage of the new energy power plant and the corrected upper and lower limits of the dynamic reactive power reserve target to the AVC substation of the new energy power plant, and the substation executes them within the station.

[0155] Therefore, this invention is based on the current status of the construction of new power systems with large-scale grid connection of new energy sources. Based on the uncertainty of new energy sources, it assesses the probability impact of power fluctuations on grid voltage, optimizes dynamic reactive power reserve targets, and provides technical support for automatic voltage control, reactive power reserve support, and safe consumption of new energy sources, thereby effectively improving the grid voltage dispatch level.

[0156] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for allocating dynamic reactive power reserve targets for new energy power plants considering power fluctuations, characterized in that, include: By reporting in real time from new energy power stations, the maximum adjustable amount of reactive power of each power station within the control area can be obtained. The target voltage value of the high-voltage side bus of each new energy power station is calculated by the regional two-level voltage optimization decision method and used as the voltage optimization target value of each new energy power station. Based on the reactive power margin method of static voltage safety domain, the upper and lower limits of the dynamic reactive power reserve target for each new energy power station in the region are calculated. Based on the ultra-short-term forecast information of new energy sources provided by external systems, assess the extreme values ​​of power output of each new energy source and the extreme values ​​of power output of new energy sources in the region within the next four hours. Based on the power grid flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, the power grid flow is calculated at the two sections with the highest and lowest extreme values ​​of regional new energy output, and the probability interval of voltage level of new energy power stations is evaluated. Based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, the upper and lower limits of the reactive power reserve target of each station are adjusted according to the voltage probability range of each new energy station. Calculate the reactive power reserve demand correction for each renewable energy station within the voltage fluctuation probability range, divided into reactive power upward regulation demand correction. Demand correction under reactive power regulation , represented as: in Let be the sensitivity of the voltage at the j-th renewable energy power station node to the reactive power of this node. , These are the upper and lower voltage limits for each new energy power station; The reactive power reserve target for each renewable energy station within the correction area is calculated by adding the demand adjustment amount to the upper and lower limits of the dynamic reactive power reserve target, as follows: The revised reactive power reserve target is compared with the maximum adjustable reactive power of new energy power plants. , After correction, the final reactive power reserve target value for each new energy station is obtained, expressed as: ； The revised upper and lower limits of reactive power reserve targets for each power station are issued to the automatic voltage control system substations of the new energy power stations, and the substations execute them within the stations.

2. The method for dynamic reactive power reserve target allocation of new energy power plants considering power fluctuations as described in claim 1, characterized in that, The control area is an automatic voltage control area formed by automatic partitioning of the main station's automatic voltage control system, characterized by strong reactive voltage coupling within the area and weak coupling between areas. The maximum adjustable reactive power capacity of each power station is the reactive power adjustable capacity reported by each renewable energy power station to the main station in real time, which is divided into maximum upward reactive power adjustment. and maximum reactive power downward adjustment , where j is the number of each new energy power station in the region.

3. The method for dynamic reactive power reserve target allocation for new energy power plants considering power fluctuations as described in claim 2, characterized in that, The upper and lower limits of the dynamic reactive power reserve target for each new energy power station include the reactive power adjustable reserve margin constraint that each new energy power station needs to maintain, which is divided into the upper limit of the reactive power reserve target. and the lower limit of reactive power reserve target .

4. The method for dynamic reactive power reserve target allocation for new energy power plants considering power fluctuations as described in claim 3, characterized in that, The assessment of the extreme values ​​of power output of each new energy source and the extreme values ​​of regional new energy power output in the next four hours includes: The maximum and minimum active power output of each renewable energy station in the next four hours are respectively , The regional renewable energy output extreme values ​​are the maximum and minimum sum of renewable energy active power output over the next four hours. , .

5. The method for allocating dynamic reactive power reserve targets for new energy power plants considering power fluctuations as described in claim 4, characterized in that, The calculation of power flow at two cross-sections, representing the highest and lowest extreme values ​​of regional renewable energy output, and the assessment of the probability interval for the voltage level of renewable energy power stations, include: The voltage levels of each renewable energy node under the two extreme value sections were calculated by power flow calculation. , Assess the voltage probability range of new energy power plants Specifically: The voltage fluctuation probability impact factor of renewable energy power plants is calculated based on the highest and lowest total renewable energy output in the region, and corrected for the short-term extreme output changes of each renewable energy plant. This correction factor includes the voltage fluctuation impact factor. Factors affecting voltage fluctuations , represented as: in, , The active power output of each new energy power station under the two extreme cross sections of the highest and lowest contribution to regional new energy; The voltage probability interval for renewable energy power plants is calculated as follows: 。 6. A system employing the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations as described in any one of claims 1 to 5, characterized in that, include: The adjustable quantity acquisition module is used to obtain the maximum vertical and horizontal adjustable quantity of reactive power of each station within the control area through real-time reporting from the new energy power stations. The high-voltage side bus voltage target value calculation module is used to calculate the high-voltage side bus voltage target value of each new energy power station through the regional two-level voltage optimization decision method, and serve as the voltage optimization target value of each new energy power station; The dynamic reactive power reserve target upper and lower limit calculation module is used to calculate the dynamic reactive power reserve target upper and lower limits for each new energy power station in the region based on the reactive power margin method of static voltage safety domain. The extreme value calculation module is used to evaluate the extreme values ​​of each new energy source output and the extreme values ​​of regional new energy output based on the ultra-short-term forecast information of new energy sources provided by external systems in the next four hours. The evaluation module is used to calculate the power flow under the two sections of the highest and lowest extreme values ​​of regional new energy output based on the power flow calculation method and the extreme values ​​of each new energy source output in the next four hours and the extreme values ​​of regional new energy output, and to evaluate the probability interval of the voltage level of new energy power stations. The correction module is used to correct the upper and lower limits of the reactive power reserve target for each renewable energy station based on the maximum adjustable amount of reactive power and the upper and lower limits of the dynamic reactive power reserve target, according to the voltage probability range of each station. Calculate the reactive power reserve demand correction for each renewable energy station within the voltage fluctuation probability range, divided into reactive power upward regulation demand correction. Demand correction under reactive power regulation , represented as: in Let be the sensitivity of the voltage at the j-th renewable energy power station node to the reactive power of this node. , These are the upper and lower voltage limits for each new energy power station; The reactive power reserve target for each renewable energy station within the correction area is calculated by adding the demand adjustment amount to the upper and lower limits of the dynamic reactive power reserve target, as follows: The revised reactive power reserve target is compared with the maximum adjustable reactive power of new energy power plants. , After correction, the final reactive power reserve target value for each new energy station is obtained, expressed as: ； The execution module is used to send the revised upper and lower limits of reactive power reserve targets for each power station to the automatic voltage control system substation of the new energy power station, and the substation performs the execution within the station.

7. A computing device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the dynamic reactive power reserve target allocation method for new energy power plants considering power fluctuations as described in any one of claims 1 to 5.

Images