A method, device and system for coordinated optimization and control of reactive power of wind-solar-storage station groups

Abstract

The present invention relates to a method, device and system for coordinated optimization and control of reactive power of a wind, solar and storage station group, belonging to the field of reactive power control technology. The method receives reactive power / voltage / power factor instructions of the power grid issued by the dispatching master station, and performs optimization calculations based on the current operating status of the wind, solar and storage and reactive compensation devices of each wind, solar and storage station, taking into account the station endpoint voltage, reactive power response time and aggregate line loss, to determine the reactive power instructions of each wind, solar and storage station. The present invention is aimed at the coordinated optimization and control of reactive power of a wind, solar and storage station group, rather than a single station or a single type of station group. On the basis of the simple consideration of proportional allocation in existing literature, it further considers the reactive power loss on the line, compensates for the reactive power shortage in the control process, and considers the reactive power adjustment correction that comprehensively considers the station endpoint voltage, reactive power response time and the station reactive power adjustable margin, thereby realizing reactive power coordinated control between wind, solar and storage station groups.

Description

Technical Field

[0001] The present invention relates to the field of reactive power regulation technology, and in particular to a method, device and system for coordinated optimization and control of reactive power of a wind-solar-storage station group. Background Art

[0002] In recent years, as the cost per kilowatt-hour (KWH) of renewable energy power plants, such as wind and photovoltaic power plants, has continued to decline, new energy power plants have rapidly entered the stage of large-scale development. With the development of large-scale renewable energy sites, wind, solar, and storage clusters are also a hot trend in the future.

[0003] The development of power electronics technology has made doubly-fed wind power generation technology increasingly mature. It can achieve decoupling control of active and reactive power through vector control of the converter. While sending active power to the grid, it also provides a certain amount of reactive power, has reactive power regulation capabilities, and can participate in the reactive voltage regulation of wind farms. Photovoltaic and energy storage are connected to the grid through converters, and also have a certain reactive voltage regulation capability. Various standards clearly define the reactive power regulation capabilities of wind, solar, and energy storage systems. GB / T 19963-2011, "Technical Regulations for the Integration of Wind Farms into Power Systems," stipulates that wind turbines must maintain a continuously adjustable power factor within a leading to lagging range of 0.95. Similarly, GB / T 19964-2012, "Technical Regulations for the Integration of Photovoltaic Power Stations into Power Systems," mandates that grid-connected inverters installed in photovoltaic power plants must maintain a continuously adjustable power factor within a leading to lagging range of 0.95 at rated active power output. GB / T 36547-2018, "Technical Regulations for the Integration of Electrochemical Energy Storage Systems into Power Grids," stipulates that energy storage systems must possess four-quadrant power control capabilities within the rated power operating range of the converter. With the increase in installed wind and photovoltaic capacity, the reactive power regulation capabilities of wind, solar, and energy storage systems are increasing significantly. How to effectively utilize this reactive power to provide reactive voltage support for the grid is a hot topic of research.

[0004] Extensive research has been conducted on reactive power and voltage control technologies for single wind and solar power plants. Research on single plants focuses on the distribution of reactive power among reactive sources and the coordination of wind, solar, and reactive compensation equipment. Some literature also examines the coordination between the stator and rotor within wind turbines. Common direct allocation methods in engineering applications include allocation based on residual reactive capacity, allocation based on wind turbine voltage sensitivity to the grid connection point, allocation based on equal power factor, allocation based on equal grid loss increment, and allocation based on distance from the grid connection point. More complex approaches utilize optimization methods to calculate the optimal reactive power regulation for various reactive sources within the plant to meet various voltage regulation objectives, including minimizing voltage deviation and minimizing power losses within the plant. The paper "Distributed cooperative voltage control of wind farms based on consensus protocol" also proposes a distributed cooperative voltage control strategy for wind farms based on a consensus protocol. This strategy provides rapid system response while distributing reactive power, eliminating steady-state voltage errors, and achieving distributed control. Regarding the coordination of wind, solar, and traditional reactive compensation equipment, the paper "Voltage Coordinated Control Strategy for Wind Farms with Doubly-Fed Induction Motors" proposes a reactive voltage control strategy that preemptively switches wind farm capacitor banks based on wind power forecasts. The output difference of the capacitor banks is borne by the doubly-fed wind turbines, while the reactive output of each doubly-fed wind turbine is adjusted according to its residual reactive power limit. This method is suitable for wind farms equipped with capacitor banks in the early stages of wind power development. The paper "Automatic Voltage Coordinated Control Strategy for Doubly-Fed Wind Farms" draws on substation integrated reactive power control methods to automatically control the reactive power and voltage of wind farms, deriving a simplified strategy for wind farm AVC partitioning diagrams. This provides a novel and practical approach for the coordinated control of wind turbine groups and centralized compensation equipment. The paper "Adaptive Reactive Compensation Coordinated Optimization Control Considering Continuous Reactive Reserve Value" proposes a coordinated optimization method for continuous / discrete reactive compensation in substations that considers the value of continuous reactive reserve. This method introduces a continuous reactive reserve benefit coefficient and differentiates the value of continuous reactive reserve based on wind power output. The paper "Hierarchical Coordinated Optimization Control Strategy for Wind Farms Based on Improved Sensitivity Algorithm" comprehensively considers the mutual coordination between wind turbines and reactive compensation equipment, and proposes a hierarchical control strategy for wind farm droop optimization based on the improved sensitivity algorithm. The optimization goal is to minimize network loss, and the droop gain coefficients of each wind turbine and reactive compensation equipment are used as variables for optimization calculations.

[0005] With multiple wind farms and energy storage investments, effective coordination between wind farm clusters offers significant advantages in improving grid security and economic efficiency. The paper "Strategy of reactive power and voltage control in large wind farms integrated region" demonstrates that, under the same reactive equipment configuration, this control strategy offers the advantages of stabilizing voltage and reducing network losses compared to traditional wind farm individual control. Consequently, inter-station reactive power and voltage control technology has become a new research hotspot, focusing on how to coordinate reactive power and voltage control between wind farm clusters. The paper "Research on the Configuration Strategy for Reactive Power Compensations in Offshore Wind Farm Clusters" proposes a reactive power control method for wind farm clusters using a simple allocation strategy, ensuring that voltages at key nodes meet requirements. The paper "Overview of Wind Park Control Strategies" calculates the voltage at the PCC to obtain the required reactive power benchmark, then dispatches reactive power from the station based on the maximum reactive power or the proportion of available reactive power. The paper "Research on Coordinated Control Strategies for Reactive Power and Voltage Optimization in Large-Scale Wind Farms" proposes a wind farm reactive power and voltage control strategy that improves the voltage distribution at the turbine terminals and, in turn, the voltage level of the entire collection system by regulating the reactive power output of wind turbines. The paper "Two-Layer Multi-Stage Voltage Coordinated Control Method for Regional Power Grids Including Wind Farm Clusters" proposes a multi-timescale reactive power coordinated control method that takes into account both fast continuous and slow discrete reactive power control devices, using a non-dominated sorting genetic algorithm to solve the multi-objective mathematical model. The paper "Reactive Power Coordination and Allocation Method for Multiple Wind Farms Connected to a Local Grid" proposes a relatively simple method for coordinated reactive power allocation among multiple wind farms in a wind power access area from different perspectives. Specifically, when the system automation level is low, allocation is based on the reactive capacity ratio of the wind farms. When the system automation level is high, a line flow distribution method is proposed based on system network constraints and basic electrical laws, and a constant network loss increment rate method is proposed based on network losses in the access area. The paper "Research on Optimization of Coordinated Control of Reactive Equipment in Wind Farms Considering Wind Power Forecasting and Voltage Distribution" considers the reactive power regulation capabilities of all wind farm dynamic reactive equipment and wind turbines in its objective function. The objective function is to reduce the voltage over-limit risk (improve the safety factor) and minimize the reactive power regulation of dynamic reactive compensation equipment and wind turbines across all wind farms, thereby deriving the reactive power regulation of wind farm reactive equipment.

[0006] For combined wind, solar, and energy storage power plants, the addition of energy storage not only smooths the active power output of the power plant cluster, but also provides peak load and load-shaving functions for the power grid, and even actively supports grid frequency regulation. Therefore, existing literature has largely focused on optimizing and controlling wind, solar, and energy storage power plant clusters for active power demand. Regarding reactive power, patent CN105591391A briefly describes a reactive voltage control method for combined wind, solar, and energy storage power plants.

[0007] Therefore, the shortcomings of the prior art are as follows:

[0008] 1. Regarding the real-time coordinated optimization and control of wind, solar and energy storage stations for reactive power regulation needs, existing research has failed to deeply consider the cluster characteristics of large-scale wind, solar and energy storage stations and the differences in the regulation characteristics of different types of reactive devices within the stations, such as the impact of reactive power response rate on the final reactive power distribution. In addition, there is little research on the coordinated control of wind, solar and energy storage combined systems, which mainly focuses on the active power optimization control of energy storage, and fails to consider the coordination with wind power and photovoltaic power in terms of reactive power regulation needs.

[0009] 2. The existing technology does not consider the reactive deviation of the reactive compensation devices in response to the grid instructions, which mainly includes the reactive loss between each station and the collection point.

[0010] 3. Most existing technologies only consider the situation where the power grid issues voltage instructions, but do not consider the power factor and reactive power instructions. Summary of the Invention

[0011] The purpose of the present invention is to provide a method, device and system for coordinated optimization and control of reactive power among wind, solar and storage station groups, so as to achieve coordinated reactive power control among wind, solar and storage station groups.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] A method for coordinated optimization and control of reactive power of a wind, solar and storage station group, comprising:

[0014] Obtaining the control parameter target value of the wind-solar-storage station group grid connection point issued by the dispatching master station; the control parameter target value includes a voltage target value, a reactive power target value or a power factor target value;

[0015] Obtain the actual measured values ​​of control parameters of wind, solar and storage station clusters and grid connection points;

[0016] When the deviation between the actual measured value of the control parameter of the wind-solar-storage station cluster grid connection point and the target value of the control parameter is not within the dead zone range, it is determined that the wind-solar-storage station cluster requires reactive power coordinated optimization control;

[0017] Calculate the reactive power demand of the wind-solar-storage-station cluster grid-connected point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter;

[0018] Based on the reactive power margin of each wind-solar-storage station and taking into account the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point, the reactive power demand of the wind-solar-storage station cluster grid connection point is distributed to each wind-solar-storage station;

[0019] According to the port voltage requirements of each wind-solar-storage station, the reactive power response time requirements of the wind-solar-storage station group, and the reactive power adjustment margin of each wind-solar-storage station, the reactive power compensation amount allocated to each wind-solar-storage station is corrected;

[0020] According to the corrected reactive compensation amount, the reactive demand of the wind-solar-storage station group grid connection point is redistributed to obtain the reactive compensation amount of each wind-solar-storage station after collaborative optimization.

[0021] Optionally, when the deviation between the actual measured value of the control parameter of the wind-solar-storage station cluster grid connection point and the target value of the control parameter is not within the dead zone range, it is determined that the wind-solar-storage station cluster requires reactive power coordinated optimization control, specifically including:

[0022] When the control parameter target value is the voltage target value, if |U ref -U measure |>U dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; Among them, U ref is the voltage target value, U measure is the actual measured voltage value at the grid connection point of the wind-solar-storage station cluster, U dead is the voltage dead zone threshold;

[0023] When the control parameter target value is the reactive power target value, if |Q ref -Q measure |>Q dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; among them, Q ref is the reactive power target value, Q measure is the actual measured reactive power value of the wind-solar-storage station group grid connection point, Q dead is the reactive dead zone threshold;

[0024] When the control parameter target value is the power factor target value, if It is determined that the wind and solar storage station group needs reactive power coordinated optimization and control; among them, is the power factor target value, is the actual measured value of the power factor at the grid connection point of the wind-solar-storage station group. is the power factor dead zone threshold.

[0025] Optionally, the calculating of reactive power demand of the wind-solar-storage-station cluster grid-connected point according to actual measured values ​​of control parameters of the wind-solar-storage-station cluster grid-connected point and the target values ​​of the control parameters specifically includes:

[0026] When the control parameter target value is the voltage target value, the formula ΔQ=(U ref -U measure ) / r and r=(U1-U2) / (Q1-Q2), calculate the reactive power demand of the wind-solar-storage station cluster grid connection point; where ΔQ is the reactive power demand of the wind-solar-storage station cluster grid connection point, r is the rate of change of the access point voltage with respect to the reactive power of the access area, U1 and U2 are the voltages of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation, and Q1 and Q2 are the reactive power of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation;

[0027] When the control parameter target value is the reactive power target value, the formula is used to calculate the actual measured value of the control parameter at the wind-solar-storage station group grid connection point and the control parameter target value. Calculate the reactive power demand of the wind-solar-storage station group grid connection point; where P rt is the predicted active power output value of the wind-solar-storage station group grid connection point in the next regulation cycle, is the tangent value corresponding to the voltage regulation instruction power factor;

[0028] When the control parameter target value is the power factor target value, the formula ΔQ=Q is used to calculate the power factor target value according to the actual measured value of the control parameter at the wind-solar-storage station group grid connection point and the control parameter target value. ref -Q measure , calculate the reactive power demand of the wind-solar-storage station cluster grid connection point.

[0029] Optionally, based on the reactive margin of each wind-solar-storage station and taking into account the reactive loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point, the reactive demand of the wind-solar-storage station cluster grid connection point is distributed to each wind-solar-storage station, specifically including:

[0030] According to the reactive margin of each wind and solar storage station, use the formula Determine the reactive power compensation distribution coefficient of each wind, solar and storage station; where K i is the reactive power compensation allocation coefficient of the i-th wind-solar-storage station, Q Ci is the reactive power margin of the i-th wind-solar storage station;

[0031] According to the reactive power compensation distribution coefficient of each wind and solar storage station, the formula ΔQ i =K i ×ΔQ, calculate the initial reactive power compensation of each wind-solar-storage station; where ΔQ i is the reactive compensation amount of the i-th wind-solar-storage station;

[0032] Based on the initial reactive power compensation of each wind-solar-storage station, the reactive power compensation allocated to each wind-solar-storage station is obtained by considering the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station group grid connection point: Where ΔQ i ′ is the reactive compensation amount allocated to the i-th wind-solar storage station, Q measure,i is the actual measured reactive power value of the i-th wind-solar storage station, X i is the reactance value of the line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point, P measure It is the real-time measurement value of active power at the grid-connected point.

[0033] Optionally, the reactive compensation amount allocated to each wind-solar-storage station is corrected according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station, specifically including:

[0034] According to the terminal voltage safe operating range of each wind, solar and storage station, the reactive compensation amount allocated to each wind, solar and storage station is corrected to obtain the reactive compensation amount after voltage correction;

[0035] According to the reactive compensation after voltage correction, considering the network loss of the aggregate line, the formula Determine the first reactive compensation amount ΔQ i *′ ; where ΔQ i * It is the reactive power compensation after voltage correction;

[0036] Determine whether the reactive power compensation amount allocated by the wind-solar-storage station is less than or equal to the maximum reactive power adjustable margin, and obtain a first determination result;

[0037] If the first judgment result indicates yes, the reactive compensation amount allocated by the wind-solar-storage station is used as the second reactive compensation amount;

[0038] If the first judgment result indicates no, the first reactive compensation amount ΔQ i *′ Corrected to the maximum reactive power adjustable margin, and the maximum reactive power adjustable margin is used as the second reactive power compensation amount;

[0039] Determine whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the reactive regulation amount corresponding to the maximum reactive response time, and obtain a second determination result;

[0040] If the second judgment result indicates yes, the reactive compensation amount allocated by the wind-solar-storage station is used as the third reactive compensation amount;

[0041] If the second judgment result indicates no, the first reactive compensation amount ΔQ i*′ Correcting it to the reactive adjustment amount corresponding to the maximum reactive response time, and using the reactive adjustment amount corresponding to the maximum reactive response time as the third reactive compensation amount;

[0042] The first reactive compensation amount ΔQ i *′ The minimum value among the second reactive compensation amount and the third reactive compensation amount is determined as the reactive compensation amount after correction of the wind-solar storage station.

[0043] Optionally, the reactive compensation amount allocated to each wind, solar and storage station is corrected according to the terminal voltage safe operating range of each wind, solar and storage station, and the corrected reactive compensation amount is used as the first reactive compensation amount, specifically including:

[0044] According to the reactive compensation amount allocated by the wind and solar storage station, the formula Calculate the terminal voltage after wind-solar-storage station compensation; where U s,i is the terminal voltage after compensation of the i-th wind-solar-storage station, P rtn,i is the sum of all active outputs of the i-th wind and solar storage station in the next regulation cycle, Q rtn,i is the sum of the reactive power on the original line and the reactive power command of the i-th wind and solar storage station, R i is the resistance value of the connecting line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point;

[0045] Determine whether the terminal voltage after compensation of wind-solar-storage station meets U min ≤U s,i ≤U max , obtain the third judgment result; wherein, U max 、U min are the maximum and minimum terminal voltages respectively;

[0046] If the third judgment result indicates yes, then the reactive compensation amount allocated by the wind-solar-storage station will not be corrected;

[0047] If the third judgment result indicates no, then the reactive compensation amount allocated to the wind-solar-storage station whose terminal voltage after compensation is greater than the terminal voltage upper limit is corrected to Or the reactive compensation amount allocated to the wind-solar-storage station whose terminal voltage after compensation is less than the lower limit of the terminal voltage is corrected to

[0048] Optionally, the reactive power demand of the wind-solar-storage station group grid connection point is redistributed according to the corrected reactive power compensation amount to obtain the reactive power compensation amount of each wind-solar-storage station after collaborative optimization, specifically including:

[0049] Obtain the difference between all reactive compensation amounts before and after correction;

[0050] Select the wind-solar-storage station that has not been calibrated for reactive compensation as the wind-solar-storage station to be calibrated;

[0051] The difference is distributed to each wind-solar-storage station to be corrected in the form of equal reactive capacity, and the latest allocated reactive compensation amount of each wind-solar-storage station to be corrected is obtained, and the step of "correcting the reactive compensation amount allocated to each wind-solar-storage station according to the terminal voltage safety operating range of each wind-solar-storage station is returned to obtain the reactive compensation amount after voltage correction" until each wind-solar-storage station satisfies the port voltage requirements, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station are compensated according to its own allocated reactive compensation amount, and the reactive compensation amount of each wind-solar-storage station after collaborative optimization is obtained.

[0052] A reactive power coordinated optimization control device for a wind, solar, and storage station group, comprising: a dispatching master station, a station group controller, and multiple station controllers;

[0053] The dispatching master station is connected to the station group controller; the dispatching master station is used to send the control parameter target values ​​of the wind, solar and storage station group grid connection points to the station group controller;

[0054] The station group controller is connected to multiple station controllers respectively; the station group controller is used to adopt the aforementioned wind, solar and storage station group reactive power collaborative optimization control method to obtain the reactive power compensation amount of each wind, solar and storage station after collaborative optimization, form a station reactive power instruction, and send the station reactive power instruction to each station controller;

[0055] Each station controller is used to execute the station reactive power instruction.

[0056] A reactive power coordinated optimization control system for a group of wind, solar and storage stations, comprising:

[0057] A control parameter target value acquisition module is used to obtain the control parameter target value of the wind-solar-storage station group grid connection point issued by the dispatching master station; the control parameter target value includes a voltage target value, a reactive power target value or a power factor target value;

[0058] The control parameter actual measurement value acquisition module is used to obtain the actual measurement values ​​of the control parameters of the wind, solar and storage station cluster grid connection points;

[0059] The reactive power collaborative optimization determination module is used to determine that the wind-solar-storage station cluster requires reactive power collaborative optimization control when the deviation between the actual measured value of the control parameter at the grid-connected point of the wind-solar-storage station cluster and the target value of the control parameter is not within the dead zone range;

[0060] A reactive power demand calculation module is used to calculate the reactive power demand of the wind-solar-storage-station cluster grid-connected point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter;

[0061] The allocation module is used to allocate the reactive power demand of the wind-solar-storage station cluster grid connection point to each wind-solar-storage station based on the reactive power margin of each wind-solar-storage station and taking into account the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point;

[0062] The correction module is used to correct the reactive compensation amount allocated to each wind-solar-storage station according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station;

[0063] The collaborative optimization module is used to redistribute the reactive power demand of the wind-solar-storage station group grid connection points according to the corrected reactive power compensation amount, and obtain the reactive power compensation amount of each wind-solar-storage station after collaborative optimization.

[0064] Optionally, the correction module specifically includes:

[0065] The voltage correction unit is used to correct the reactive compensation amount allocated to each wind, solar and storage station according to the terminal voltage safe operating range of each wind, solar and storage station, and obtain the reactive compensation amount after voltage correction;

[0066] The first reactive compensation amount determination unit is used to consider the network loss of the aggregate line according to the reactive compensation after voltage correction, and use the formula Determine the first reactive compensation amount ΔQ i *′ ; where ΔQ i *′ It is the reactive power compensation after voltage correction;

[0067] The first judgment unit is used to judge whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the maximum reactive adjustable margin, and obtain a first judgment result;

[0068] a first judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the second reactive compensation amount if the first judgment result indicates yes;

[0069] The second reactive compensation amount determination unit is configured to set the first reactive compensation amount ΔQ i *′ Corrected to the maximum reactive power adjustable margin, and the maximum reactive power adjustable margin is used as the second reactive power compensation amount;

[0070] The second judgment unit is used to judge whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the reactive adjustment amount corresponding to the maximum reactive response time, and obtain a second judgment result;

[0071] a second judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the third reactive compensation amount if the second judgment result indicates yes;

[0072] The third reactive compensation amount determination unit is configured to determine the first reactive compensation amount ΔQ if the second judgment result indicates no. i *′ Correcting it to the reactive adjustment amount corresponding to the maximum reactive response time, and using the reactive adjustment amount corresponding to the maximum reactive response time as the third reactive compensation amount;

[0073] The reactive compensation amount correction determination unit is used to determine the first reactive compensation amount ΔQ i *′ The minimum value among the second reactive compensation amount and the third reactive compensation amount is determined as the reactive compensation amount after correction of the wind-solar storage station.

[0074] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0075] The present invention discloses a method, device, and system for coordinated reactive optimization and control of a wind, solar, and storage station cluster. The method receives reactive power / voltage / power factor instructions for the power grid issued by a dispatching master station, performs optimization calculations based on the current operating status of the wind, solar, and storage stations and reactive compensation devices, and takes into account the station endpoint voltage, reactive power response time, and aggregate line loss to determine the reactive power instructions for each wind, solar, and storage station. The present invention is directed to coordinated reactive optimization and control of a wind, solar, and storage station cluster, rather than a single station or a single type of station cluster. Based on the simple consideration of proportional allocation in existing literature, it further considers reactive power losses on the line, compensates for reactive power shortages in the control process, and considers reactive power regulation correction that comprehensively considers station endpoint voltage, reactive power response time, and station reactive power adjustable margin, thereby achieving coordinated reactive power control between wind, solar, and storage station clusters. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0077] Figure 1 Flowchart of the method for coordinated optimization and control of reactive power of a wind-solar-storage station group provided in Example 1 of the present invention;

[0078] Figure 2 A brief flow chart of the method for coordinated optimization and control of reactive power of a wind-solar-storage station group provided in Example 1 of the present invention;

[0079] Figure 3 Schematic diagram of the reactive power coordinated optimization control method for a wind-solar-storage station group provided in Example 1 of the present invention;

[0080] Figure 4 A schematic diagram showing the distribution of the ports and collection points of various stations provided in Example 1 of the present invention;

[0081] Figure 5 This is a structural diagram of the reactive power collaborative optimization and control device for a wind-solar-storage station group provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0082] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0083] The purpose of the present invention is to provide a method, device and system for coordinated optimization and control of reactive power among wind, solar and storage station groups, so as to achieve coordinated reactive power control among wind, solar and storage station groups.

[0084] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0085] Example 1

[0086] The present invention provides a method for coordinated optimization and control of reactive power of wind-solar-storage station groups. Figure 1-3 As shown, the following steps are included:

[0087] Step S1, obtaining the control parameter target value of the wind-solar-storage station group grid connection point issued by the dispatching master station; the control parameter target value includes a voltage target value, a reactive power target value or a power factor target value.

[0088] The station group AVC obtains the wind, solar and storage station group grid connection point control target value issued by the dispatching master station AVC: U in constant voltage mode ref , Q in constant reactive mode ref , constant power factor

[0089] Step S2: obtaining actual measured values ​​of control parameters of the wind-solar-storage station cluster grid connection points.

[0090] Step S3: When the deviation between the actual measured value of the control parameter of the wind-solar-storage station cluster and the target value of the control parameter is not within the dead zone, it is determined that the wind-solar-storage station cluster requires reactive power coordinated optimization and control.

[0091] Exemplarily, the determination process is:

[0092] When the control parameter target value is the voltage target value, if |U ref -U measure |>U dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; Among them, U ref is the voltage target value, U measure is the actual measured voltage value at the grid connection point of the wind-solar-storage station cluster, U dead is the voltage dead zone threshold;

[0093] When the control parameter target value is the reactive power target value, if |Q ref -Q measure |>Q dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; among them, Q ref is the reactive power target value, Q measure is the actual measured reactive power value of the wind-solar-storage station group grid connection point, Q dead is the reactive dead zone threshold;

[0094] When the control parameter target value is the power factor target value, if It is determined that the wind and solar storage station group needs reactive power coordinated optimization and control; among them, is the power factor target value, is the actual measured value of the power factor at the grid connection point of the wind-solar-storage station group. is the power factor dead zone threshold.

[0095] After determining that coordinated optimization and control of the station group is necessary, continue with the subsequent steps.

[0096] Step S4, calculating the reactive power demand of the wind-solar-storage-station cluster grid-connected point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter.

[0097] Reactive power setting is performed for different types of instructions. Reactive power setting refers to calculating the overall reactive power demand ΔQ of the station group based on different instructions and actual measurement values ​​of the grid connection point.

[0098] (1) For voltage instructions, when the operating status does not change much, the rate of change of the access point voltage with respect to the reactive power of the access area is approximately calculated based on the local operating information of two adjacent measurement cycles, and the overall reactive power demand of the station group is obtained:

[0099] Using the formula ΔQ=(U ref -U measure ) / r and r=(U1-U2) / (Q1-Q2), calculate the reactive power demand of the wind-solar-storage station cluster grid connection point;

[0100] Among them, ΔQ is the reactive power demand of the grid-connected point of the wind-solar-storage station cluster, r is the rate of change of the access point voltage with respect to the reactive power of the access area, U1 and U2 are the grid-connected point voltages of the wind-solar-storage station cluster in two adjacent measurement cycles under stable operation, and Q1 and Q2 are the reactive power of the grid-connected point of the wind-solar-storage station cluster in two adjacent measurement cycles under stable operation;

[0101] (2) For the power factor instruction, the latest real-time active power dispatch curve is used to determine the predicted active power output value of the grid connection point in the next control cycle. Based on the power factor instruction, the overall reactive power demand of the station group is obtained:

[0102] Using the formula Calculate the reactive power demand at the grid connection point of the wind, solar and storage station cluster;

[0103] Among them, P rt It is the predicted value of the active power output of the wind-solar-storage station group connected to the grid in the next regulation cycle. It is a fixed value in the voltage regulation instruction cycle. Compared with the real-time measurement value of the active power of the grid connection point P measure , which is more suitable for setting the reactive power of the next regulation cycle; It is the tangent value corresponding to the power factor of the voltage regulation instruction, with leading being positive and lagging being negative;

[0104] (3) For reactive power instructions, the difference between the AVC instruction and the actual measured value is the reactive power demand of the entire station group:

[0105] Using the formula ΔQ=Q ref -Q measure , calculate the reactive power demand of the wind-solar-storage station cluster grid connection point.

[0106] Step S5: Based on the reactive margin of each wind-solar-storage station and taking into account the reactive loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point, the reactive demand of the wind-solar-storage station cluster grid connection point is distributed to each wind-solar-storage station.

[0107] According to the technical standards for reactive power control of new energy stations, the overall reactive power control response time of the station group is less than 30s. Therefore, in engineering applications, the distribution method is often used for reactive power control to achieve rapid response requirements. The station group controller distributes the reactive power to each station according to the reactive power margin information received from each station. The relationship between each station port and the collection point (grid connection point) is as follows: Figure 4 shown.

[0108] The reactive power compensation allocation coefficient of each station is determined based on the reactive margin reported by each station:

[0109]

[0110] Among them, K i is the reactive power compensation allocation coefficient of the i-th wind-solar-storage station, QCi is the reactive power margin of the i-th wind-solar storage station.

[0111] Each station obtains the reactive power compensation amount through the distribution coefficient.

[0112] ΔQ i =K i ×ΔQ

[0113] Where ΔQ i is the reactive compensation amount of the i-th wind-solar-storage station.

[0114] Compared with the equipment inside the stations, the stations are geographically distributed more widely, the lines from the stations to the collection stations are longer, and the power flowing on the lines is larger, resulting in line power loss, especially reactive loss. Therefore, this patent mainly considers the power loss between the stations and the collection stations, and the reactive loss within the stations is further considered by the station control. Taking into account the reactive loss on the line caused by changes in reactive compensation and active output, the reactive compensation required at each station port also includes the reactive loss on the line caused by power transmission:

[0115]

[0116] Where ΔQ i ′ is the reactive compensation amount allocated to the i-th wind-solar storage station, Q measure,i is the actual measured reactive power value of the i-th wind-solar storage station, X i is the reactance value of the line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point, P measure It is the real-time measurement value of active power at the grid-connected point.

[0117] Step S6: Correct the reactive compensation amount allocated to each wind-solar-storage station according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station.

[0118] Corrections are made based on the port voltage requirements of each station, the reactive power response time requirements of the wind, solar and storage station group, and the reactive power adjustable margin of each station until all stations meet the requirements.

[0119] (1) Determine whether the voltage at the station terminal meets the safe operating range based on the reactive compensation amount of each station.

[0120] According to the reactive compensation amount allocated by the wind and solar storage station, the formula Calculate the terminal voltage after compensation of the wind, solar and storage station.

[0121] Among them, U s,i is the terminal voltage after compensation of the i-th wind-solar-storage station, P rtn,iis the active power of the tie line in the next regulation cycle calculated by the real-time dispatch instruction, that is, the sum of all active outputs of the i-th wind-solar storage station in the next regulation cycle; Q rtn,i is the reactive power of the tie line before correction, which is the sum of the reactive power on the original line and the reactive power instruction of the i-th wind-solar storage station; R i is the resistance value of the connecting line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point.

[0122] If the terminal voltage after compensation of the wind-solar-storage station meets U min ≤U s,i ≤U max , then no reactive adjustment correction is performed. max 、U min are the maximum and minimum terminal voltages respectively;

[0123] If U s,i >U max , then the reactive compensation amount at the i-th station port is corrected:

[0124]

[0125] If U s,i <U min , then the reactive compensation amount at the i-th station port is corrected:

[0126]

[0127] This is the reactive power regulation of each station after correction based on the voltage constraint at the station end. Considering the aggregate line network loss, the reactive power instruction of each station at the station port is calculated:

[0128]

[0129] (2) Determine whether the reactive power compensation amount of each station meets the adjustable reactive power margin of the station based on the reactive power compensation amount established for each station.

[0130] ΔQ C,i =ΔQ C,wt,i +ΔQ C,pv,i +ΔQ C,ess,i +ΔQ C,svg,i

[0131] Where ΔQ C,i is the total reactive power regulation of station i, ΔQ C,wt,i is the reactive power regulation of the wind turbine in station i, ΔQ C,pv,i is the reactive power regulation of photovoltaic power in station i, ΔQ C,ess,i is the reactive regulation of energy storage in station i, ΔQ C,svg,i is the reactive regulation of energy storage in station i.

[0132] When the reactive compensation amount allocated by the wind and solar storage station is less than or equal to the maximum reactive adjustable margin, no reactive adjustment amount correction is performed.

[0133] When the reactive power regulation amount allocated to station i exceeds the adjustable margin, the actual regulation amount is corrected to the maximum adjustable margin.

[0134] When the reactive power regulation amount allocated to station i exceeds the adjustable margin, the actual regulation amount is corrected to the maximum adjustable margin, that is:

[0135] If ΔQ i ′>ΔQ C,i , then the reactive compensation amount at the station port of the i-th station is corrected:

[0136] ΔQ i *′ =ΔQ C,i

[0137] (3) Determine whether the reactive response time t required by the power grid is met based on the reactive compensation amount of each station. s , where the reactive response time of the wind, solar and storage station group refers to the time required for reactive voltage control to start from receiving the reactive power / voltage control instruction issued in real time (or pre-set) by the dispatching AVC until the change in the actual reactive power / voltage value of the station group reaches 90% of the difference between the control target value and the initial value.

[0138] ΔQ pro,i =min{α wt,i t s ,ΔQ C,wt,i}+min{α pv,i t s ,ΔQ C,pv,i}+min{α ess,i t s ,ΔQ C,ess,i}+min{α svg,i t s ,ΔQ C,svg,i}

[0139] Among them, α wt,i , α pv,i , α ess,i , α svg,i Respectively represent the reactive power regulation rate of wind turbines, photovoltaics, energy storage, and SVG in each station, ΔQ pro,i Represents reactive power response time t s The maximum reactive power regulation that can be provided.

[0140] When the reactive compensation amount allocated by the wind-solar storage station is less than or equal to the reactive regulation amount corresponding to the maximum reactive response time, no reactive regulation amount correction is performed.

[0141] When the reactive power response time t s When the maximum available reactive power regulation amount cannot meet 90% of the allocated reactive power regulation demand, correction is required, and the actual regulation amount is corrected to the maximum available reactive power regulation amount, that is:

[0142] If ΔQ i ′>ΔQ pro,i , then the reactive compensation amount at the station port of the i-th station is corrected:

[0143] ΔQ i *′ =ΔQ pro,i

[0144] In order to ensure that the station meets the above three correction conditions at the same time, the minimum value of the results of (1), (2) and (3) is taken as the reactive compensation amount at the station port for the final correction.

[0145] Correct the reactive adjustment amount at each station port, and distribute the difference in reactive compensation before and after correction to the remaining uncorrected stations according to the principle of equal reactive capacity. Re-judge whether these stations meet the port voltage requirements, the reactive response time requirements of the wind, solar and storage station group, and the reactive adjustment margin of each station. If not, repeat the correction and distribution process to ultimately ensure that the reactive compensation amount of all stations meets various constraints, and issue the station adjustment instructions.

[0146] Step S7: Redistribute the reactive power demand of the wind-solar-storage station group grid connection points according to the corrected reactive power compensation amount, and obtain the reactive power compensation amount of each wind-solar-storage station after collaborative optimization.

[0147] After the correction, the remaining stations will then distribute reactive power according to equal reactive capacity, ultimately ensuring that the reactive compensation amount of each station meets various constraints, and the station adjustment instructions will be issued.

[0148] Exemplarily, collaborative optimization specifically includes:

[0149] Obtain the difference between all reactive compensation amounts before and after correction;

[0150] Select the wind-solar-storage station that has not been calibrated for reactive compensation as the wind-solar-storage station to be calibrated;

[0151] The difference is distributed to each wind-solar storage station to be corrected in the form of equal reactive capacity, and the latest reactive compensation amount allocated to each wind-solar storage station to be corrected is obtained, and the step "According to the reactive compensation amount allocated by the wind-solar storage station, use the formula Calculate the terminal voltage after compensation of the wind-solar-storage station" until each wind-solar-storage station satisfies the terminal voltage requirements, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station according to its allocated reactive compensation amount, and obtain the reactive compensation amount of each wind-solar-storage station after collaborative optimization.

[0152] This invention is designed for engineering applications and considers the grid connection of multiple wind, solar, and storage stations through a collection point. To achieve steady-state voltage regulation, the real-time coordinated optimization and control of reactive power across a cluster of wind, solar, and storage stations primarily coordinates reactive power resources across the cluster, ensuring safe and economical operation within the cluster while ensuring that the cluster meets external grid requirements. According to the "04-QND 1040514-2020 Inner Mongolia Power Grid Automatic Voltage Control (AVC) Technical Specification", the AVC of the station group should realize the control of the bus voltage and gateway reactive power (power factor) in each control area. Therefore, considering the three situations of receiving voltage instructions, reactive power instructions and power factor instructions at the grid connection point of the station group, combined with the characteristics of wind turbines, photovoltaics, energy storage and SVG in the wind, solar and storage stations to reactive power instructions, reactive power adjustable capacity, and the problem of reactive power transmission loss between the station and the grid connection point, the distribution method of AVC instructions among the station group is optimized, and a reactive power coordinated optimization control strategy for the wind, solar and storage station group is constructed. While following the superior voltage regulation instructions, the voltage at each station and the overall reactive power response time of the station group are guaranteed to meet the requirements of the grid and be within the safe and stable operation range. This ensures the safe and economic operation of the station group, meets the diversified regulation needs of the station group, realizes intelligent coordinated reactive power control of the wind, solar and storage stations, and gives full play to the grid-connected functional characteristics of the wind, solar and storage stations.

[0153] The advantages of the present invention are as follows:

[0154] 1. This invention is aimed at the coordinated optimization and control of reactive power of a wind, solar and storage station group, rather than a single station or a single type of station group;

[0155] 2. This invention takes into account the response characteristics of different types of reactive power generation devices (wind turbines, energy storage, photovoltaics, and SVG), fully unleashing the potential of renewable energy in participating in reactive power regulation and improving the efficiency of coordinated reactive power regulation in a cluster of stations.

[0156] 3. The lines from the renewable energy collection point to each station are long, and the reactive power loss is significant and difficult to ignore. This invention further considers the reactive power loss on the line on the basis of the simple proportional distribution considered in the existing literature, making up for the reactive power shortage in the control process and improving the control accuracy;

[0157] 4. Based on the existing literature that only considers voltage instructions, this invention further considers the real-time reactive power collaborative optimization control method of wind, solar and storage station groups under reactive power instructions and power factor instructions in accordance with current standard requirements, which is closer to actual engineering applications.

[0158] Example 2

[0159] A wind-solar-storage station group reactive power coordinated optimization control device, such as Figure 5 As shown, it includes: a dispatching master station, a station group controller and multiple station controllers.

[0160] The dispatching master station is connected to the station cluster controller; it issues target control parameter values ​​for the wind, solar, and storage station cluster grid connection points to the station cluster controller. The station cluster controller is connected to multiple station controllers. The station cluster controller utilizes the aforementioned wind, solar, and storage station cluster reactive power coordinated optimization control method to obtain the reactive compensation amount for each wind, solar, and storage station after coordinated optimization, generate station reactive power instructions, and issue these instructions to each station controller. Each station controller executes the station reactive power instructions.

[0161] The station group coordination controller receives the grid reactive power / voltage / power factor instructions issued by the dispatching master station, and performs optimization calculations based on the current operating status of the wind, solar and storage and reactive compensation devices SVG of each wind, solar and storage station, taking into account the station terminal voltage, reactive power response time and collection line loss. After determining the reactive power instructions of each wind, solar and storage station, the instructions are sent to the control systems of each wind, solar and storage station to realize coordinated optimization control of reactive power of the wind, solar and storage station group.

[0162] Example 3

[0163] The embodiment of the present invention provides a reactive power collaborative optimization control system for a wind, solar and storage station group, including:

[0164] The control parameter target value acquisition module is used to obtain the control parameter target values ​​of the wind-solar-storage station group grid connection points issued by the dispatching master station; the control parameter target values ​​include voltage target value, reactive power target value or power factor target value;

[0165] The control parameter actual measurement value acquisition module is used to obtain the actual measurement values ​​of the control parameters of the wind, solar and storage station cluster grid connection points;

[0166] The reactive power collaborative optimization judgment module is used to determine that the wind, solar and storage station cluster requires reactive power collaborative optimization control when the deviation between the actual measured value of the control parameter at the grid connection point of the wind, solar and storage station cluster and the target value of the control parameter is not within the dead zone range;

[0167] The reactive power demand calculation module is used to calculate the reactive power demand of the wind-solar-storage-station cluster grid connection point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid connection point and the target value of the control parameter;

[0168] The allocation module is used to allocate the reactive power demand of the wind-solar-storage station cluster grid connection point to each wind-solar-storage station based on the reactive power margin of each wind-solar-storage station and taking into account the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point;

[0169] The correction module is used to correct the reactive compensation amount allocated to each wind-solar-storage station according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station;

[0170] The collaborative optimization module is used to redistribute the reactive power demand of the wind-solar-storage station group grid connection points according to the corrected reactive power compensation amount, and obtain the reactive power compensation amount of each wind-solar-storage station after collaborative optimization.

[0171] The reactive power collaborative optimization judgment module specifically includes:

[0172] The first determination unit is used for, when the control parameter target value is the voltage target value, if |U ref -U measure |>U dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; Among them, U ref is the voltage target value, U measure is the actual measured voltage value at the grid connection point of the wind-solar-storage station cluster, U dead is the voltage dead zone threshold;

[0173] The second determination unit is used for, when the control parameter target value is the reactive power target value, if |Q ref -Q measure |>Q dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; among them, Q ref is the reactive power target value, Q measure is the actual measured reactive power value of the wind-solar-storage station group grid connection point, Q dead is the reactive dead zone threshold;

[0174] The third determination unit is used for determining that when the control parameter target value is the power factor target value, It is determined that the wind and solar storage station group needs reactive power coordinated optimization and control; among them, is the power factor target value, is the actual measured value of the power factor at the grid connection point of the wind-solar-storage station group. is the power factor dead zone threshold.

[0175] Reactive demand calculation module, specifically including:

[0176] The first reactive power demand calculation unit is used to calculate the reactive power demand using the formula ΔQ=(U ref -U measure) / r and r=(U1-U2) / (Q1-Q2), calculate the reactive power demand of the wind-solar-storage station cluster grid connection point; where ΔQ is the reactive power demand of the wind-solar-storage station cluster grid connection point, r is the rate of change of the access point voltage with respect to the reactive power of the access area, U1 and U2 are the voltages of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation, and Q1 and Q2 are the reactive power of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation;

[0177] The second reactive power demand calculation unit is used to calculate the reactive power demand when the target value of the control parameter is the reactive power target value, according to the actual measured value of the control parameter of the wind-solar storage station group grid connection point and the target value of the control parameter, using the formula Calculate the reactive power demand of the wind-solar-storage station group grid connection point; where P rt is the predicted active power output value of the wind-solar-storage station group grid connection point in the next regulation cycle, is the tangent value corresponding to the voltage regulation command power factor;

[0178] The third reactive power demand calculation unit is used to calculate the reactive power demand using the formula ΔQ=Q according to the actual measured value of the control parameter and the target value of the control parameter at the wind-solar-storage station group grid connection point when the target value of the control parameter is the power factor target value. ref -Q measure , calculate the reactive power demand of the wind-solar-storage station cluster grid connection point.

[0179] Correction module, specifically including:

[0180] The voltage correction unit is used to correct the reactive compensation amount allocated to each wind, solar and storage station according to the terminal voltage safe operating range of each wind, solar and storage station, and obtain the reactive compensation amount after voltage correction;

[0181] The first reactive compensation amount determination unit is used to consider the network loss of the collection line according to the reactive compensation after voltage correction, and use the formula Determine the first reactive compensation amount ΔQ i *′ ; where ΔQ i * It is the reactive power compensation after voltage correction;

[0182] The first judgment unit is used to judge whether the reactive power compensation amount allocated by the wind-solar-storage station is less than or equal to the maximum reactive power adjustable margin, and obtain a first judgment result;

[0183] a first judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the second reactive compensation amount if the first judgment result indicates yes;

[0184] The second reactive compensation amount determination unit is configured to set the first reactive compensation amount ΔQ i*′ Corrected to the maximum reactive power adjustable margin, and the maximum reactive power adjustable margin is used as the second reactive power compensation amount;

[0185] The second judgment unit is used to judge whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the reactive adjustment amount corresponding to the maximum reactive response time, and obtain a second judgment result;

[0186] a second judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the third reactive compensation amount if the second judgment result indicates yes;

[0187] The third reactive compensation amount determination unit is configured to determine the first reactive compensation amount ΔQ if the second judgment result indicates no. i *′ Correcting it to the reactive adjustment amount corresponding to the maximum reactive response time, and using the reactive adjustment amount corresponding to the maximum reactive response time as the third reactive compensation amount;

[0188] The reactive compensation amount correction determination unit is used to determine the first reactive compensation amount ΔQ i *′ The minimum value among the second reactive compensation amount and the third reactive compensation amount is determined as the reactive compensation amount after correction of the wind-solar storage station.

[0189] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0190] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for coordinated optimization and control of reactive power of a wind, solar and storage station group, characterized in that: include: Obtain the control parameter target values ​​of the wind, solar and storage station cluster grid connection points issued by the dispatching master station; The control parameter target value includes a voltage target value, a reactive power target value or a power factor target value; Obtain the actual measured values ​​of control parameters of wind, solar and storage station clusters and grid connection points; When the deviation between the actual measured value of the control parameter of the wind-solar-storage station cluster grid connection point and the target value of the control parameter is not within the dead zone range, it is determined that the wind-solar-storage station cluster requires reactive power coordinated optimization control; Calculate the reactive power demand of the wind-solar-storage-station cluster grid-connected point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter; Based on the reactive power margin of each wind-solar-storage station and taking into account the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point, the reactive power demand of the wind-solar-storage station cluster grid connection point is distributed to each wind-solar-storage station; According to the port voltage requirements of each wind-solar-storage station, the reactive power response time requirements of the wind-solar-storage station group, and the reactive power adjustment margin of each wind-solar-storage station, the reactive power compensation amount allocated to each wind-solar-storage station is corrected; Based on the corrected reactive compensation amount, the reactive demand of the wind, solar and storage station cluster grid connection points is redistributed to obtain the reactive compensation amount of each wind, solar and storage station after collaborative optimization; The reactive compensation amount allocated to each wind-solar-storage station is corrected according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station, specifically including: According to the terminal voltage safe operating range of each wind, solar and storage station, the reactive compensation amount allocated to each wind, solar and storage station is corrected to obtain the reactive compensation amount after voltage correction; According to the reactive compensation after voltage correction, considering the network loss of the aggregate line, the formula Determine the first reactive compensation amount ΔQ i *′ ; where ΔQ i * is the reactive power compensation after voltage correction; Q measure,i is the actual measured reactive power value of the i-th wind-solar storage station, X i is the reactance value of the line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point, U measure is the actual measured voltage value at the grid connection point of the wind-solar-storage station group, P rt is the predicted active output value of the wind-solar-storage station group grid connection point in the next regulation cycle, P measure It is the real-time measurement value of active power at the grid connection point; Determine whether the reactive power compensation amount allocated by the wind-solar-storage station is less than or equal to the maximum reactive power adjustable margin, and obtain a first determination result; If the first judgment result indicates yes, the reactive compensation amount allocated by the wind-solar-storage station is used as the second reactive compensation amount; If the first judgment result indicates no, the first reactive compensation amount ΔQ i *′ Corrected to the maximum reactive power adjustable margin, and the maximum reactive power adjustable margin is used as the second reactive power compensation amount; Determine whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the reactive regulation amount corresponding to the maximum reactive response time, and obtain a second determination result; If the second judgment result indicates yes, the reactive compensation amount allocated by the wind-solar-storage station is used as the third reactive compensation amount; If the second judgment result indicates no, the first reactive compensation amount ΔQ i *′ Correcting it to the reactive adjustment amount corresponding to the maximum reactive response time, and using the reactive adjustment amount corresponding to the maximum reactive response time as the third reactive compensation amount; The first reactive compensation amount ΔQ i *′ The minimum value among the second reactive compensation amount and the third reactive compensation amount is determined as the reactive compensation amount after correction of the wind-solar storage station.

2. The method for coordinated optimization and control of reactive power of wind, solar and storage stations according to claim 1 is characterized in that: When the deviation between the actual measured value of the control parameter of the wind-solar-storage station cluster grid connection point and the target value of the control parameter is not within the dead zone range, it is determined that the wind-solar-storage station cluster requires reactive power coordinated optimization control, specifically including: When the control parameter target value is the voltage target value, if |U ref -U measure |>U dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; Among them, U ref is the voltage target value, U dead is the voltage dead zone threshold; When the control parameter target value is the reactive power target value, if |Q ref -Q measure |>Q dead , it is determined that the wind and solar storage station group needs reactive power coordinated optimization control; among them, Q ref is the reactive power target value, Q measure is the actual measured reactive power value of the wind-solar-storage station group grid connection point, Q dead is the reactive dead zone threshold; When the control parameter target value is the power factor target value, if It is determined that the wind and solar storage station group needs reactive power coordinated optimization and control; among them, is the power factor target value, is the actual measured value of the power factor at the grid connection point of the wind-solar-storage station group. is the power factor dead zone threshold.

3. The method for coordinated optimization and control of reactive power of wind, solar and storage stations according to claim 2 is characterized in that: The calculating of the reactive power demand of the wind-solar-storage-station cluster grid-connected point according to the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter specifically includes: When the control parameter target value is the voltage target value, the formula ΔQ=(U ref -U measure ) / r and r=(U1-U2) / (Q1-Q2), calculate the reactive power demand of the wind-solar-storage station cluster grid connection point; where ΔQ is the reactive power demand of the wind-solar-storage station cluster grid connection point, r is the rate of change of the access point voltage with respect to the reactive power of the access area, U1 and U2 are the voltages of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation, and Q1 and Q2 are the reactive power of the wind-solar-storage station cluster grid connection point in two adjacent measurement cycles under stable operation; When the control parameter target value is the reactive power target value, the formula is used to calculate the actual measured value of the control parameter at the wind-solar-storage station group grid connection point and the control parameter target value. Calculate the reactive power demand at the grid connection point of the wind-solar-storage station group; is the tangent value corresponding to the voltage regulation instruction power factor; When the control parameter target value is the power factor target value, the formula ΔQ=Q is used to calculate the power factor target value according to the actual measured value of the control parameter at the wind-solar-storage station group grid connection point and the control parameter target value. ref -Q measure , calculate the reactive power demand of the wind-solar-storage station cluster grid connection point.

4. The method for coordinated optimization and control of reactive power of wind, solar and storage stations according to claim 3 is characterized in that: Based on the reactive margin of each wind-solar-storage station and taking into account the reactive loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point, the reactive demand of the wind-solar-storage station cluster grid connection point is distributed to each wind-solar-storage station, specifically including: According to the reactive margin of each wind and solar storage station, use the formula Determine the reactive power compensation distribution coefficient of each wind, solar and storage station; where K i is the reactive power compensation allocation coefficient of the i-th wind-solar-storage station, Q Ci is the reactive power margin of the i-th wind-solar storage station; According to the reactive power compensation distribution coefficient of each wind and solar storage station, the formula ΔQ i =K i ×ΔQ, calculate the initial reactive power compensation of each wind-solar-storage station; where ΔQ i is the reactive compensation amount of the i-th wind-solar-storage station; Based on the initial reactive power compensation of each wind-solar-storage station, the reactive power compensation allocated to each wind-solar-storage station is obtained by considering the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station group grid connection point: Where ΔQ i ′ is the reactive compensation amount allocated to the i-th wind-solar-storage station.

5. The method for coordinated optimization and control of reactive power of wind, solar and storage stations according to claim 4 is characterized in that: The reactive compensation amount allocated to each wind, solar and storage station is corrected according to the terminal voltage safe operating range of each wind, solar and storage station, and the corrected reactive compensation amount is used as the first reactive compensation amount, specifically including: According to the reactive compensation amount allocated by the wind and solar storage station, the formula Calculate the terminal voltage after compensation of wind-solar-storage station; where U s,i is the terminal voltage after compensation of the i-th wind-solar-storage station, P rtn,i is the sum of all active outputs of the i-th wind and solar storage station in the next regulation cycle, Q rtn,i is the sum of the reactive power on the original line and the reactive power command of the i-th wind and solar storage station, R i is the resistance value of the connecting line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point; Determine whether the terminal voltage after compensation of wind-solar-storage station meets U min ≤U s,i ≤U max , obtain the third judgment result; wherein, U max 、U min are the maximum and minimum terminal voltages respectively; If the third judgment result indicates yes, then the reactive compensation amount allocated by the wind-solar-storage station will not be corrected; If the third judgment result indicates no, then the reactive compensation amount allocated to the wind-solar-storage station whose terminal voltage after compensation is greater than the terminal voltage upper limit is corrected to Or the reactive compensation amount allocated to the wind-solar-storage station whose terminal voltage after compensation is less than the lower limit of the terminal voltage is corrected to 6. The method for coordinated optimization and control of reactive power of wind, solar and storage stations according to claim 4 is characterized in that: The reactive power demand of the wind-solar-storage station group grid connection point is redistributed according to the corrected reactive power compensation amount to obtain the reactive power compensation amount of each wind-solar-storage station after collaborative optimization, specifically including: Obtain the difference between all reactive compensation amounts before and after correction; Select the wind-solar-storage station that has not been calibrated for reactive compensation as the wind-solar-storage station to be calibrated; The difference is distributed to each wind-solar-storage station to be corrected in the form of equal reactive capacity, and the latest allocated reactive compensation amount of each wind-solar-storage station to be corrected is obtained, and the step of "correcting the reactive compensation amount allocated to each wind-solar-storage station according to the terminal voltage safety operating range of each wind-solar-storage station is returned to obtain the reactive compensation amount after voltage correction" until each wind-solar-storage station satisfies the port voltage requirements, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station is compensated according to its own allocated reactive compensation amount, and the reactive compensation amount of each wind-solar-storage station after collaborative optimization is obtained.

7. A wind-solar-storage station group reactive power collaborative optimization control device, characterized in that: include: Dispatching master station, station group controller and multiple station controllers; The dispatching master station is connected to the station group controller; The dispatching master station is used to send the control parameter target values ​​of the wind, solar and storage station group grid connection points to the station group controller; The station group controller is connected to multiple station controllers respectively; the station group controller is used to adopt the reactive power coordinated optimization control method of the wind, solar and storage station group according to any one of claims 1 to 6, obtain the reactive power compensation amount of each wind, solar and storage station after coordinated optimization, form a station reactive power instruction, and send the station reactive power instruction to each station controller; Each station controller is used to execute the station reactive power instruction.

8. A wind-solar-storage station group reactive power coordinated optimization control system, characterized in that: include: The control parameter target value acquisition module is used to obtain the control parameter target values ​​of the wind-solar-storage station group grid connection points issued by the dispatching master station; The control parameter target value includes a voltage target value, a reactive power target value or a power factor target value; The control parameter actual measurement value acquisition module is used to obtain the actual measurement values ​​of the control parameters of the wind, solar and storage station cluster grid connection points; The reactive power collaborative optimization determination module is used to determine that the wind-solar-storage station cluster requires reactive power collaborative optimization control when the deviation between the actual measured value of the control parameter at the grid-connected point of the wind-solar-storage station cluster and the target value of the control parameter is not within the dead zone range; A reactive power demand calculation module is used to calculate the reactive power demand of the wind-solar-storage-station cluster grid-connected point based on the actual measured value of the control parameter of the wind-solar-storage-station cluster grid-connected point and the target value of the control parameter; The allocation module is used to allocate the reactive power demand of the wind-solar-storage station cluster grid connection point to each wind-solar-storage station based on the reactive power margin of each wind-solar-storage station and taking into account the reactive power loss of the collection line between the wind-solar-storage station and the wind-solar-storage station cluster grid connection point; The correction module is used to correct the reactive compensation amount allocated to each wind-solar-storage station according to the port voltage requirements of each wind-solar-storage station, the reactive response time requirements of the wind-solar-storage station group, and the reactive adjustable margin of each wind-solar-storage station; The collaborative optimization module is used to redistribute the reactive power demand of the wind, solar and storage station cluster grid connection points according to the corrected reactive power compensation amount, and obtain the reactive power compensation amount of each wind, solar and storage station after collaborative optimization; The correction module specifically includes: The voltage correction unit is used to correct the reactive compensation amount allocated to each wind, solar and storage station according to the terminal voltage safe operating range of each wind, solar and storage station, and obtain the reactive compensation amount after voltage correction; The first reactive compensation amount determination unit is used to consider the network loss of the aggregate line according to the reactive compensation after voltage correction, and use the formula Determine the first reactive compensation amount ΔQ i *′ ; where ΔQ i * is the reactive power compensation after voltage correction; Q measure,i is the actual measured reactive power value of the i-th wind-solar storage station, X i is the reactance value of the line between the i-th wind-solar-storage station and the wind-solar-storage station cluster grid connection point, U measure is the actual measured voltage value at the grid connection point of the wind-solar-storage station group, P rt is the predicted active output value of the wind-solar-storage station group grid connection point in the next regulation cycle, P measure It is the real-time measurement value of active power at the grid connection point; The first judgment unit is used to judge whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the maximum reactive adjustable margin, and obtain a first judgment result; a first judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the second reactive compensation amount if the first judgment result indicates yes; The second reactive compensation amount determination unit is configured to set the first reactive compensation amount ΔQ i *′ Corrected to the maximum reactive power adjustable margin, and the maximum reactive power adjustable margin is used as the second reactive power compensation amount; The second judgment unit is used to judge whether the reactive compensation amount allocated by the wind-solar-storage station is less than or equal to the reactive adjustment amount corresponding to the maximum reactive response time, and obtain a second judgment result; a second judgment result unit, configured to use the reactive compensation amount allocated by the wind-solar-storage station as the third reactive compensation amount if the second judgment result indicates yes; The third reactive compensation amount determination unit is configured to determine the first reactive compensation amount ΔQ if the second judgment result indicates no. i *′ Correcting it to the reactive adjustment amount corresponding to the maximum reactive response time, and using the reactive adjustment amount corresponding to the maximum reactive response time as the third reactive compensation amount; The reactive compensation amount correction determination unit is used to determine the first reactive compensation amount ΔQ i *′ The minimum value among the second reactive compensation amount and the third reactive compensation amount is determined as the reactive compensation amount after correction of the wind-solar storage station.

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