Photovoltaic power generation harmonic comprehensive treatment method and system

Abstract

The invention discloses a photovoltaic power generation harmonic wave comprehensive treatment method and system, aims to realize comprehensive treatment of photovoltaic power generation harmonic waves, and belongs to the technical field of photovoltaic power generation harmonic wave treatment, and the method comprises the steps: generating a photovoltaic power generation information graph of a target area; performing harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information graph to obtain a harmonic evaluation result; marking the photovoltaic power stations with unqualified harmonic evaluation results as to-be-optimized power stations; generating a corresponding recommended optimization mode for the to-be-optimized power station, and guiding the to-be-optimized power station to perform harmonic optimization processing according to the recommended optimization mode; aiming at the key technical bottleneck of harmonic pollution under the background of large-scale grid connection of photovoltaic power generation, the method can dynamically control the harmonic influence in the region according to the management demand, improves the management capability of the photovoltaic power generation harmonic, and achieves the comprehensive treatment of the photovoltaic power generation harmonic.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic power generation harmonic control, and specifically relates to a photovoltaic power generation harmonic comprehensive control method and system. Background Art

[0002] With the large-scale integration of photovoltaic power generation into the grid, harmonic pollution has become a key technical bottleneck hindering the safe and stable operation of the power grid and improving the efficiency of photovoltaic systems. Currently, photovoltaic inverters, as core power electronic devices, experience significant harmonic components in their output current due to their high-frequency switching. Especially under low-power operation or sudden changes in sunlight, harmonic distortion (THD) can exceed national standards, causing voltage waveform distortion and a decrease in power factor. These harmonics not only increase grid line losses and transformer heating, but can also cause overload and damage to capacitor compensation devices through resonant amplification. They can even interfere with the sensitivity and reliability of relay protection devices, threatening the overall safety of the power system.

[0003] Based on this, in order to achieve comprehensive control of photovoltaic power generation harmonics, the present invention provides a method and system for comprehensive control of photovoltaic power generation harmonics. Summary of the Invention

[0004] In order to solve the problems existing in the above solutions, the present invention provides a method and system for comprehensive control of photovoltaic power generation harmonics.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A comprehensive method for controlling photovoltaic power generation harmonics, comprising: Generate a photovoltaic power generation information map for the target area, wherein the photovoltaic power generation information map is used to collect power generation information of each photovoltaic power station in the target area, wherein the power generation information includes location information of the photovoltaic power station, photovoltaic equipment information, and harmonic processing information; Conduct harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information diagram to obtain harmonic evaluation results, including qualified harmonic evaluation and unqualified harmonic evaluation results; mark the photovoltaic power station with unqualified harmonic evaluation results as a power station to be optimized; Generate corresponding recommended optimization methods for the power station to be optimized, and guide the power station to be optimized to perform harmonic optimization processing according to the recommended optimization methods.

[0006] Furthermore, the generation of the photovoltaic power generation information map includes: Obtaining grid-connected records of photovoltaic power generation in a target area, and identifying photovoltaic power stations in the target area in real time based on the grid-connected records; Identify the power generation information of each photovoltaic power station and generate a photovoltaic power generation information map of the target area based on the power generation information of each photovoltaic power station.

[0007] Furthermore, harmonic evaluation of each photovoltaic power station is performed based on the photovoltaic power generation information diagram, including: The harmonic characteristics of the photovoltaic power station are obtained according to the photovoltaic power generation information diagram; a harmonic evaluation model is established, and the expression of the harmonic evaluation model is: ; Where: s is the harmonic characteristic, the output data is the harmonic evaluation value PX (s), and the harmonic evaluation value is 1 or 0; Analyzing the harmonic characteristics through a harmonic evaluation model to obtain corresponding harmonic evaluation values; When the harmonic evaluation value is 1, the harmonic evaluation result is qualified; When the harmonic evaluation value is 0, the harmonic evaluation result is that the harmonic evaluation fails.

[0008] Furthermore, the acquisition of harmonic characteristics includes: identifying power generation information of the photovoltaic power station according to the photovoltaic power generation information graph, and matching a reference case according to the power generation information; A harmonic feature corresponding to a reference case is identified, and the harmonic feature is used as a harmonic feature of the photovoltaic power station.

[0009] Furthermore, the power generation information is calibrated.

[0010] Furthermore, the acquisition of harmonic characteristics includes: Identify power generation information of corresponding photovoltaic power stations according to the photovoltaic power generation information diagram, classify the photovoltaic power stations according to the power generation information, and obtain several photovoltaic classifications; Matching corresponding reference cases to each photovoltaic power station in the photovoltaic classification, and obtaining harmonic conditions of each photovoltaic power station in real time; obtaining harmonic characteristics of the corresponding photovoltaic power station based on the harmonic conditions and the reference cases, and marking the harmonic characteristics as harmonic reference characteristics; A photovoltaic power station is selected from the photovoltaic classification as a reference power station, and harmonic monitoring is performed on the reference power station to obtain harmonic characteristics of corresponding harmonic conditions; the harmonic reference characteristics of the harmonic conditions of the photovoltaic power station in the photovoltaic classification are corrected according to the harmonic conditions, harmonic characteristics and harmonic reference characteristics of the reference power station to obtain harmonic characteristics of the corresponding photovoltaic power station.

[0011] Furthermore, photovoltaic power stations are classified according to power generation information, including: Matching a corresponding reference case to the photovoltaic power station based on the power generation information; presetting harmonic conditions of the photovoltaic power station, performing feature recognition on the reference case based on the harmonic conditions, and obtaining harmonic features corresponding to the corresponding harmonic conditions; integrating the respective harmonic features into a classification feature set of the photovoltaic power station; The similarity between each classification feature set is calculated, and whether the corresponding photovoltaic power stations meet the classification requirements is determined based on the similarity; photovoltaic power stations that meet the classification requirements are classified into one category, and so on, to obtain several photovoltaic classifications.

[0012] Furthermore, a corresponding recommended optimization method is generated for the power station to be optimized, including: Establishing an optimization method library, wherein the optimization method library is used to store reserve optimization methods, wherein the reserve optimization methods are used to optimize harmonic effects of photovoltaic power stations; A matching analysis is performed on the power station to be optimized according to the optimization method library to obtain a reserve optimization method that meets the matching requirements, and the reserve optimization method is marked as a candidate optimization method; the candidate optimization methods are screened to obtain a recommended optimization method.

[0013] Furthermore, the optimization methods to be selected are screened, including: Estimate the harmonic optimization value and optimization cost of the selected optimization method, and mark the harmonic optimization value and optimization cost as XB and CB respectively; Substitute the harmonic optimization value and optimization cost into the preset screening formula to calculate the screening value of the corresponding candidate optimization method. Select the recommended optimization method based on the filter value.

[0014] Furthermore, the screening formula is: ; Where: SP is the screening value; e is the natural constant.

[0015] Furthermore, the screening formula is: ; Where: SP is the screening value; e is the natural constant; , X1 is the threshold.

[0016] A photovoltaic power generation harmonic comprehensive control system, including an information module, a harmonic analysis module, and a control auxiliary module; The information module is used to generate a photovoltaic power generation information map of the target area and dynamically update the photovoltaic power generation information map; The harmonic analysis module is used to perform harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information diagram, obtain harmonic evaluation results, and determine the power station to be optimized according to the harmonic evaluation results; The control auxiliary module is used to generate a corresponding recommended optimization method for the power station to be optimized, and guide the power station to be optimized to perform harmonic optimization processing according to the recommended optimization method.

[0017] Compared with the prior art, the present invention has the following beneficial effects: Addressing the key technical bottleneck of harmonic pollution in the context of large-scale grid-connected photovoltaic power generation, this invention dynamically manages harmonic impacts within a region based on management needs, improving the ability to manage photovoltaic power generation harmonics and achieving comprehensive harmonic management. This comprehensive harmonic management improves the power quality of the photovoltaic system, enhances the efficiency and stability of photovoltaic power generation, and helps enhance the overall performance of the photovoltaic system. This is of great significance for promoting the large-scale development of the photovoltaic power generation industry and increasing the proportion of renewable energy in the energy structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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 or the description of the prior art. 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.

[0019] Figure 1 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0020] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all 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.

[0021] like Figure 1 As shown, a comprehensive method for controlling photovoltaic power generation harmonics includes: Determine the target area, which is the distribution network area that needs to be comprehensively managed for photovoltaic power generation harmonics; obtain the grid connection records of photovoltaic power generation in the target area, and identify the photovoltaic power stations in the target area in real time based on the grid connection records. Personal photovoltaic power generation grid connection is also regarded as a photovoltaic power station; identify the power generation information of each photovoltaic power station, which mainly includes photovoltaic equipment information, location, and harmonic processing information adopted. The harmonic processing information mainly includes the method, equipment and other related information for harmonic processing; generate a photovoltaic power generation information map of the target area based on the power generation information of each photovoltaic power station.

[0022] Conduct harmonic assessment on each photovoltaic power station based on the photovoltaic power generation information diagram to determine whether the harmonic processing of the corresponding photovoltaic power station meets the preset standards and obtain the corresponding harmonic assessment results, which include qualified and unqualified harmonic assessments; The photovoltaic power station with the harmonic assessment result of unqualified is marked as a power station to be optimized, indicating that harmonic processing optimization is needed; Generates recommended optimization methods for the power plants to be optimized and guides them in harmonic optimization according to the recommended optimization methods. Provides early warnings to management personnel, displays each power plant to be optimized and the recommended optimization methods, and then guides and instructs the power plants to implement harmonic optimization according to the requirements.

[0023] In one embodiment, harmonic evaluation of each photovoltaic power station is performed based on the photovoltaic power generation information graph. The evaluation can be performed based on existing methods, such as manually detecting the harmonic conditions, and then determining whether the preset standards are met.

[0024] In one embodiment, harmonic evaluation of each photovoltaic power station is performed based on the photovoltaic power generation information map, including: Obtain the harmonic characteristics of the corresponding photovoltaic power station based on the photovoltaic power generation information diagram. The harmonic characteristics are the grid-connected harmonic characteristics of the photovoltaic power station, such as the total voltage harmonic distortion rate. A harmonic evaluation model is established. The expression of the harmonic evaluation model is: ; Where: s is the input data, harmonic characteristics, and the preset standard can be set according to international standards, domestic standards, or user-defined standards; the output data is the harmonic evaluation value PX(s), and the harmonic evaluation value is 1 or 0; training is performed using historical harmonic characteristics and preset standards; Analyze the corresponding harmonic characteristics through the harmonic evaluation model to obtain the corresponding harmonic evaluation value; When the harmonic evaluation value is 1, the harmonic evaluation result is qualified; When the harmonic evaluation value is 0, the harmonic evaluation result is that the harmonic evaluation fails.

[0025] In one embodiment, obtaining harmonic characteristics includes: The power generation information of the corresponding photovoltaic power station is identified based on the photovoltaic power generation information map. A reference case is matched based on the power generation information. The reference case is a grid-connected case with real harmonic data that is identical or similar to the photovoltaic equipment information and harmonic processing information in the power generation information. The harmonic characteristics corresponding to the reference case are identified and used as the harmonic characteristics of the photovoltaic power station.

[0026] In one embodiment, in order to determine the accuracy of power generation information, the power generation information of each photovoltaic power station may be calibrated to prevent corresponding personnel from submitting false information. Specifically, the calibration may be performed in a variety of ways.

[0027] In one embodiment, obtaining harmonic characteristics includes: Identify power generation information of corresponding photovoltaic power stations according to the photovoltaic power generation information diagram, classify the photovoltaic power stations according to the power generation information, and obtain several photovoltaic classifications; Matching corresponding reference cases to each photovoltaic power station in the photovoltaic classification, and obtaining the harmonic conditions of each photovoltaic power station in real time; obtaining the harmonic characteristics of the corresponding photovoltaic power station based on the harmonic conditions and reference cases, and marking the harmonic characteristics as harmonic reference characteristics; A photovoltaic power station is selected from the photovoltaic classification as a reference station, and harmonic monitoring is performed on the reference station to obtain the harmonic characteristics of the corresponding harmonic conditions. Specifically, a corresponding harmonic monitoring device is installed at the reference station, or the existing harmonic monitoring device at the reference station is used for monitoring. The harmonic reference characteristics of the harmonic conditions of other photovoltaic power stations in the photovoltaic classification are corrected based on the harmonic conditions, harmonic characteristics, and harmonic reference characteristics of the reference station to obtain the harmonic characteristics of the corresponding photovoltaic power station. Specifically, the harmonic characteristics and harmonic reference characteristics of the reference station under the corresponding harmonic conditions are used to determine the corresponding adjustment relationship, and then the harmonic reference characteristics of the harmonic conditions of other photovoltaic power stations are corrected. Generally, intelligent algorithms such as deep learning algorithms and machine learning algorithms are used to establish a corresponding intelligent correction model, establish a corresponding training set for training, and analyze the successfully trained intelligent correction model.

[0028] In one embodiment, a photovoltaic power station is selected from the photovoltaic classification as a reference power station. The selection is made based on low cost and ease of harmonic monitoring, such as a photovoltaic power station equipped with harmonic monitoring equipment. The selection is made specifically based on the needs of management personnel.

[0029] In one embodiment, photovoltaic power stations are classified according to power generation information, and photovoltaic power stations with the same or similar power generation information are classified into one category. Classification can also be performed based on existing classification methods, such as classification based on a clustering algorithm.

[0030] In one embodiment, photovoltaic power stations are classified according to power generation information, including: Matching reference cases to photovoltaic power stations based on power generation information; presetting harmonic conditions for photovoltaic power stations. Harmonic conditions are dynamic conditions that can cause harmonic changes, such as lighting conditions, grid asymmetry faults, and inverter parallel operation. Feature recognition is performed on reference cases based on the harmonic conditions to obtain harmonic features corresponding to the corresponding harmonic conditions; each harmonic feature is integrated into a classification feature set for the photovoltaic power station; and the harmonic features within the classification feature set are sorted in the order corresponding to the harmonic conditions to facilitate subsequent similarity calculations at corresponding positions. Calculate the similarity between each classification feature set, and judge whether the corresponding photovoltaic power stations meet the classification requirements based on the similarity. If they meet the classification requirements, they are classified into one category. Generally, the comparison and judgment are based on the preset value. If the similarity is not less than the preset value, it is considered to meet the classification requirements; Photovoltaic power stations that meet the classification requirements are classified into one category, and so on to obtain several photovoltaic classifications.

[0031] In one embodiment, generating a corresponding recommended optimization method for the power plant to be optimized includes: Establish an optimization method library, which is used to store various optimization methods applicable to harmonic processing of photovoltaic power stations and is marked as a reserve optimization method; Perform matching analysis on the power station to be optimized based on the optimization method library to obtain a reserve optimization method that meets the matching requirements of the power station to be optimized. That is, determine whether it can achieve the optimization effect on the photovoltaic power station based on the optimization part of the corresponding reserve optimization method, and whether the harmonic assessment result of the optimized reserve optimization method is qualified; mark the matched reserve optimization method as the candidate optimization method; Filter the optimization methods to be selected and obtain recommended optimization methods.

[0032] In one embodiment, a matching analysis is performed on the power station to be optimized based on the optimization method library. The matching analysis can be performed using existing analysis methods, such as using intelligent algorithms such as machine learning to establish a corresponding effect evaluation model for intelligent analysis; or using technologies such as digital twins to establish a corresponding digital twin for simulation analysis. Specifically, there are multiple ways to determine whether the corresponding reserve optimization method meets the matching requirements of the power station to be optimized.

[0033] In one embodiment, screening the optimization methods to be selected includes: Estimate the harmonic optimization value and optimization cost of the selected optimization method. The harmonic optimization value is the estimated degree of harmonic reduction. For example, if the total harmonic current distortion (THDi) is reduced from 12% to 3.5%, the harmonic optimization value = (12-3.5) / 12. The corresponding harmonic optimization value is determined by performing the effect analysis method described in the above embodiment. The optimization cost is the estimated cost required to implement the selected optimization method. The harmonic optimization value and optimization cost are marked as XB and CB respectively; Substitute the harmonic optimization value and optimization cost into the preset screening formula to calculate the screening value of the corresponding candidate optimization method. The screening formula is: ; Where: SP is the screening value; e is the natural constant; Select the recommended optimization method based on the filter value, such as selecting the candidate optimization method with the largest filter value as the recommended optimization method; you can also sort by the filter value and select several candidate optimization methods as the recommended optimization method.

[0034] In one embodiment, the screening formula is: ; Where: SP is the screening value; e is the natural constant; , X1 is the threshold, which represents the maximum optimization cost that the power station to be optimized can accept. It can be set by the corresponding management personnel and the power station to be optimized, or it can be set intelligently according to the scale of the power station to be optimized.

[0035] In one embodiment, a corresponding recommended optimization method is generated for the power station to be optimized, and the recommended optimization method can be generated based on an existing method.

[0036] A photovoltaic power generation harmonic comprehensive control system, including an information module, a harmonic analysis module, and a control auxiliary module; The information module is used to generate a photovoltaic power generation information map of the target area and dynamically update the photovoltaic power generation information map; The harmonic analysis module is used to perform harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information diagram, obtain harmonic evaluation results, and determine the power station to be optimized according to the harmonic evaluation results; The control auxiliary module is used to generate a corresponding recommended optimization method for the power station to be optimized, and guide the power station to be optimized to perform harmonic optimization processing according to the recommended optimization method.

[0037] The above formulas are all calculated by removing dimensions and taking their numerical values. The formula is a formula that is closest to the actual situation obtained by collecting a large amount of data and performing software simulation. The preset parameters and preset thresholds in the formula are set by technicians in this field according to actual conditions or obtained by simulating a large amount of data.

[0038] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A comprehensive method for controlling photovoltaic power generation harmonics, characterized in that: include: Generate a photovoltaic power generation information map for the target area, wherein the photovoltaic power generation information map is used to collect power generation information of each photovoltaic power station in the target area, wherein the power generation information includes location information of the photovoltaic power station, photovoltaic equipment information, and harmonic processing information; Conduct harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information diagram to obtain harmonic evaluation results, including qualified harmonic evaluation and unqualified harmonic evaluation results; mark the photovoltaic power station with unqualified harmonic evaluation results as a power station to be optimized; Generate corresponding recommended optimization methods for the power station to be optimized, and guide the power station to be optimized to perform harmonic optimization processing according to the recommended optimization methods.

2. A photovoltaic power generation harmonic comprehensive control method according to claim 1, characterized in that: Generation of photovoltaic power generation information graph, including: Obtaining grid-connected records of photovoltaic power generation in a target area, and identifying photovoltaic power stations in the target area in real time based on the grid-connected records; Identify the power generation information of each photovoltaic power station and generate a photovoltaic power generation information map of the target area based on the power generation information of each photovoltaic power station.

3. A photovoltaic power generation harmonic comprehensive control method according to claim 1, characterized in that: Harmonic evaluation of each photovoltaic power station is performed based on the photovoltaic power generation information diagram, including: The harmonic characteristics of the photovoltaic power station are obtained according to the photovoltaic power generation information diagram; a harmonic evaluation model is established, and the expression of the harmonic evaluation model is: ； Where: s is the harmonic characteristic, the output data is the harmonic evaluation value PX (s), and the harmonic evaluation value is 1 or 0; Analyzing the harmonic characteristics through a harmonic evaluation model to obtain corresponding harmonic evaluation values; When the harmonic evaluation value is 1, the harmonic evaluation result is qualified; When the harmonic evaluation value is 0, the harmonic evaluation result is that the harmonic evaluation fails.

4. A photovoltaic power generation harmonic comprehensive control method according to claim 3, characterized in that: Acquisition of harmonic characteristics, including: identifying power generation information of the photovoltaic power station according to the photovoltaic power generation information graph, and matching a reference case according to the power generation information; A harmonic feature corresponding to a reference case is identified, and the harmonic feature is used as a harmonic feature of the photovoltaic power station.

5. A photovoltaic power generation harmonic comprehensive control method according to claim 2, characterized in that: The power generation information is calibrated.

6. A photovoltaic power generation harmonic comprehensive control method according to claim 3, characterized in that: Acquisition of harmonic characteristics, including: Identify power generation information of corresponding photovoltaic power stations according to the photovoltaic power generation information diagram, classify the photovoltaic power stations according to the power generation information, and obtain several photovoltaic classifications; Matching corresponding reference cases to each photovoltaic power station in the photovoltaic classification, and obtaining harmonic conditions of each photovoltaic power station in real time; obtaining harmonic characteristics of the corresponding photovoltaic power station based on the harmonic conditions and the reference cases, and marking the harmonic characteristics as harmonic reference characteristics; A photovoltaic power station is selected from the photovoltaic classification as a reference power station, and harmonic monitoring is performed on the reference power station to obtain harmonic characteristics of corresponding harmonic conditions; the harmonic reference characteristics of the harmonic conditions of the photovoltaic power station in the photovoltaic classification are corrected according to the harmonic conditions, harmonic characteristics and harmonic reference characteristics of the reference power station to obtain harmonic characteristics of the corresponding photovoltaic power station.

7. A photovoltaic power generation harmonic comprehensive control method according to claim 6, characterized in that: Photovoltaic power stations are classified according to power generation information, including: Matching a corresponding reference case to the photovoltaic power station based on the power generation information; presetting harmonic conditions of the photovoltaic power station, performing feature recognition on the reference case based on the harmonic conditions, and obtaining harmonic features corresponding to the corresponding harmonic conditions; integrating the respective harmonic features into a classification feature set of the photovoltaic power station; The similarity between each classification feature set is calculated, and whether the corresponding photovoltaic power stations meet the classification requirements is determined based on the similarity; photovoltaic power stations that meet the classification requirements are classified into one category, and so on, to obtain several photovoltaic classifications.

8. The photovoltaic power generation harmonic comprehensive control method according to claim 1, characterized in that: Generate corresponding recommended optimization methods for the power plant to be optimized, including: Establishing an optimization method library, wherein the optimization method library is used to store reserve optimization methods, wherein the reserve optimization methods are used to optimize harmonic effects of photovoltaic power stations; A matching analysis is performed on the power station to be optimized according to the optimization method library to obtain a reserve optimization method that meets the matching requirements, and the reserve optimization method is marked as a candidate optimization method; the candidate optimization methods are screened to obtain a recommended optimization method.

9. The photovoltaic power generation harmonic comprehensive control method according to claim 1, characterized in that: The screening formula is: ； Where: SP is the screening value; e is the natural constant.

10. A photovoltaic power generation harmonic comprehensive control system, characterized in that: A photovoltaic power generation harmonic comprehensive control method according to any one of claims 1 to 9 is implemented, comprising an information module, a harmonic analysis module, and a control auxiliary module; The information module is used to generate a photovoltaic power generation information map of the target area and dynamically update the photovoltaic power generation information map; The harmonic analysis module is used to perform harmonic evaluation on each photovoltaic power station according to the photovoltaic power generation information diagram, obtain harmonic evaluation results, and determine the power station to be optimized according to the harmonic evaluation results; The control auxiliary module is used to generate a corresponding recommended optimization method for the power station to be optimized, and guide the power station to be optimized to perform harmonic optimization processing according to the recommended optimization method.

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