Method and system for measuring and analyzing harmonic content of power grid

Abstract

The invention provides a power grid harmonic content measurement and analysis method and system, and belongs to the technical field of electrical variable measurement and analysis, and the method specifically comprises the steps: determining a harmonic content analysis result of a branch line according to use data and harmonic content abnormal values of different harmonic abnormal equipment combinations, and when the harmonic content analysis result meets the requirements, determining the harmonic content analysis result of the branch line; the method comprises the following steps: determining harmonic abnormal probabilities of different time periods on the basis of use data of harmonic abnormal equipment combinations of different time periods, positioning a measurement time period of a measurement instrument by using the harmonic abnormal probabilities, and determining the harmonic measurement analysis duration of the measurement time period according to the harmonic abnormal probabilities of the measurement time period. And whether the measuring instrument can be used by using the branch is determined based on the harmonic measurement result within the harmonic measurement analysis duration, so that the accuracy of harmonic detection analysis is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric variable measurement, and in particular relates to a method and system for measuring and analyzing harmonic content of a power grid. Background Art

[0002] In the field of petrochemicals, power harmonics may cause the measurement accuracy of measuring instruments to fail to meet the requirements. Therefore, how to measure and analyze the harmonic content of the power grid and generate differentiated management and control measures in a targeted manner is crucial to the measurement accuracy of measuring instruments.

[0003] Specifically, in the invention patent application CN202410756438.6 "A three-phase multifunctional standard harmonic energy meter and a three-phase harmonic energy measurement method", a processing module connected by multiple multi-channel AD synchronous conversion modules is used to process the measured signal, which improves the accuracy and efficiency of the measurement analysis. However, it is not difficult to find the following technical problems through analysis: Grid harmonics are not static, but will change with the changes in the harmonic content injected into the grid by the connected power equipment. Therefore, during the measurement and analysis of grid harmonics, if the grid harmonic content cannot be determined based on the analysis results of the grid harmonics at different times, the accuracy of the assessment of the grid harmonic content cannot be guaranteed.

[0004] In view of the above technical problems, the present invention provides a method and system for measuring and analyzing harmonic content in a power grid. Summary of the invention

[0005] To achieve the purpose of the present invention, the present invention adopts the following technical solutions: According to one aspect of the present invention, a method for measuring and analyzing harmonic content in a power grid is provided.

[0006] A method for measuring and analyzing harmonic content in a power grid, specifically comprising: S1 divides the power supply line into multiple branch lines, uses a harmonic monitoring device to determine the harmonic content data of the branch lines at different times, and determines the abnormal harmonic content values ​​of different combinations of electrical equipment in combination with the start-up data of electrical equipment of the branch lines at different times, and determines the abnormal harmonic device combination in the electrical equipment combination based on the abnormal harmonic content value; S2 determines the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determines the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations, and when the harmonic content analysis result meets the requirements, proceeds to the next step; S3 determines the harmonic abnormality probability of different time periods based on the usage data of the harmonic abnormality equipment combination in different time periods, and uses the harmonic abnormality probability to locate the measurement time period of the measuring instrument; S4 determines the harmonic measurement analysis duration of the measurement period according to the harmonic abnormality probability of the measurement period, and determines whether the branch circuit can be used for the measurement instrument based on the harmonic measurement result within the harmonic measurement analysis duration.

[0007] A further technical solution is to divide the power supply line into multiple branch lines, specifically including: According to the tapping data of the power supply line in different power distribution devices, the power supply line is divided into a plurality of independent branch lines.

[0008] A further technical solution is that the harmonic content data includes the harmonic content of the power supply line at different harmonic frequencies.

[0009] A further technical solution is that when the harmonic anomaly probability of the time period is within a preset probability interval, the time period is determined to be a measurement period.

[0010] A further technical solution is that the harmonic measurement analysis duration of the measurement period is determined according to a preset analysis duration corresponding to the harmonic anomaly probability of the measurement period.

[0011] A further technical solution is to determine whether the branch circuit can be used to perform the measurement instrument, specifically including: Determining harmonic measurement results at different moments within the harmonic measurement analysis time period based on the harmonic measurement results within the harmonic measurement analysis time period; Determine the harmonic abnormal moments within the harmonic measurement and analysis duration according to the harmonic measurement results at different times, and determine the basic abnormal value within the harmonic measurement and analysis duration according to the number ratio of the harmonic abnormal moments; Based on the number of intervals between different harmonic abnormal moments, the maximum duration of the harmonic abnormal period within the harmonic measurement and analysis duration is determined, and based on the maximum duration, the aggregated abnormal value within the harmonic measurement and analysis duration is determined; The sum of the basic abnormal value and the aggregated abnormal value is used to determine the harmonic monitoring abnormal value within the harmonic measurement and analysis time period, and whether the branch line can be used for the measurement instrument is determined according to the harmonic monitoring abnormal value.

[0012] A further technical solution is that when the harmonic monitoring abnormal value is not within a preset abnormal interval, it is determined that the branch circuit cannot be used for the measurement instrument.

[0013] On the other hand, an embodiment of the present application provides a power grid harmonic content measurement and analysis system, which adopts the above-mentioned power grid harmonic content measurement and analysis method, specifically including: Abnormal combination determination module, harmonic content assessment module, measurement period positioning module, assessment result output module; The abnormal combination determination module is responsible for dividing the power supply line into multiple branch lines, using the harmonic monitoring equipment to determine the harmonic content data of the branch lines at different times, and combining the start-up data of the electrical equipment of the branch lines at different times to determine the abnormal values ​​of the harmonic content of different electrical equipment combinations, and determining the abnormal harmonic equipment combination in the electrical equipment combination based on the abnormal values ​​of the harmonic content; The harmonic content evaluation module is responsible for determining the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determining the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations; The measurement period positioning module is responsible for determining the harmonic anomaly probability of different time periods based on the usage data of the harmonic abnormal device combination in different time periods, and positioning the measurement period of the measuring instrument using the harmonic anomaly probability; The evaluation result output module is responsible for determining the harmonic measurement analysis duration of the measurement period based on the harmonic abnormality probability of the measurement period, and determining whether the branch circuit can be used for measuring instrument use based on the harmonic measurement results within the harmonic measurement analysis duration.

[0014] The beneficial effects of the present invention are: 1. The harmonic content data of the branch line at different times and the opening data of the electrical equipment of the branch line at different times are used to determine the combination of equipment with abnormal harmonics, thereby realizing the corresponding relationship between the measurement results of the harmonic content and the use of the electrical equipment to determine the combination of electrical equipment with abnormal harmonics, and also laying a foundation for further using the use data of the electrical equipment combination of the branch line to perform harmonic measurement and analysis of the branch line, thereby improving the accuracy of the harmonic measurement and analysis results of the branch line; 2. Determine whether the branch circuit can be used for measuring instruments based on the harmonic measurement results within the harmonic measurement and analysis period, thereby avoiding the influence of large harmonics on the accuracy of the use of measuring instruments and improving the accuracy of the measurement results of the measuring instruments. Further combined with the harmonic measurement results within a certain period of time, it also realizes the accurate evaluation of the harmonic content of the current measurement period from a longer time dimension, thus laying the foundation for the normal use of the measuring instruments.

[0015] Other features and advantages will be described in the following description, and partly become apparent from the description, or understood by practicing the invention. The purpose and other advantages of the invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0018] Figure 1 It is a flow chart of a method for measuring and analyzing harmonic content of a power grid; Figure 2 is a flow chart of a method for determining an abnormal value of harmonic content of a combination of electrical equipment; Figure 3 It is a flow chart of the method of determining the harmonic abnormality probability. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0020] The scheme will be described below through Example 1 and Example 2: Example 1

[0021] To solve the above problems, according to one aspect of the present invention, Figure 1 According to one aspect of the present invention, a method for measuring and analyzing harmonic content in a power grid is provided, which specifically includes: S1 divides the power supply line into multiple branch lines, uses a harmonic monitoring device to determine the harmonic content data of the branch lines at different times, and determines the abnormal harmonic content values ​​of different combinations of electrical equipment in combination with the start-up data of electrical equipment of the branch lines at different times, and determines the abnormal harmonic device combination in the electrical equipment combination based on the abnormal harmonic content value; Furthermore, the power supply line is divided into multiple branch lines, specifically including: According to the tapping data of the power supply line in different power distribution devices, the power supply line is divided into a plurality of independent branch lines.

[0022] It should be noted that the harmonic content data includes the harmonic content of the power supply line at different harmonic frequencies.

[0023] It is understandable that if Figure 2 As shown, the method for determining the abnormal value of the harmonic content of the electrical equipment combination is: Determining the matching start-up time period of the combination of electrical devices based on the start-up data of the electrical devices at different times; Dividing the matching on period into different power intervals based on the delivered power of the matching on period, and determining the harmonic abnormality values ​​of the different power intervals based on the harmonic contents at different harmonic frequencies of the different power intervals; The weight values ​​of different power intervals are determined by the proportion of operating time in different power intervals, the weight values ​​of different power intervals and harmonic anomaly values ​​are used to determine the weight sum of harmonic anomaly values, and the weight sum of the harmonic anomaly values ​​is used as the harmonic content anomaly value of the electrical equipment combination.

[0024] Furthermore, the harmonic abnormal value is determined according to the sum of the maximum values ​​of the proportions of the harmonic contents at different harmonic frequencies.

[0025] It can be understood that when the abnormal value of the harmonic content of the electrical equipment combination is not within the preset abnormal value range, the electrical equipment combination is determined to be a harmonic abnormal equipment combination.

[0026] It should also be noted that the method for determining the abnormal value of the harmonic content of the electrical equipment combination includes steps S11-S13, specifically: S11 determines the matching start-up time period of the electrical equipment combination based on the start-up data of the electrical equipment at different times; Optionally, before entering step S12, the following steps are further included: The matching start-up time period of the electrical equipment combination is determined by the start-up data of the electrical equipment at different times, and it is judged whether there is a time period in the matching start-up time period when the harmonic content does not meet the requirements. If so, proceed to the next step; if not, it is determined that the electrical equipment combination does not belong to the harmonic abnormal equipment combination.

[0027] S12 divides the matching start period into different power intervals based on the transmission power of the matching start period, determines the power intervals in which the harmonic content does not meet the requirements based on the harmonic content data of the different power intervals, and uses them as the power intervals with excessive harmonic content, and determines the harmonic abnormality values ​​of the different power intervals based on the harmonic content at different harmonic frequencies of the different power intervals; S13 determines the weight values ​​of different power intervals according to the proportion of operating time in different power intervals, uses the weight values ​​of different power intervals and harmonic anomaly values ​​to determine the weight sum of harmonic anomaly values, and uses the weight sum of the harmonic anomaly values ​​as the harmonic content anomaly value of the electrical equipment combination.

[0028] S2 determines the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determines the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations, and when the harmonic content analysis result meets the requirements, proceeds to the next step; In one embodiment, the method for determining the harmonic content analysis result of the branch line is: Based on the usage data of different harmonic abnormal device combinations, the usage duration of different harmonic abnormal device combinations in different time periods is determined, and the usage duration in different time periods is used to determine the screening usage time periods, and the usage discreteness of the harmonic abnormal device combinations is determined based on the number proportion of the screening usage time periods; Obtaining the cumulative usage time of the harmonic abnormal device combination, and determining the frequency of use of the harmonic abnormal device based on the cumulative usage time of the harmonic abnormal device combination; The equipment weight values ​​of different harmonic abnormality combinations are determined according to the weights of the frequency of use and the discreteness of use, and the harmonic abnormality degree value of the branch line is determined in combination with the harmonic content abnormality values ​​of different harmonic abnormality equipment combinations; the harmonic content analysis result of the branch line is determined based on the harmonic abnormality degree value.

[0029] Further, determining the harmonic content analysis result of the branch line based on the harmonic abnormality value specifically includes: The harmonic abnormality level value is used to determine the corresponding state of the branch line under the harmonic abnormality level, and the harmonic content analysis result of the branch line is determined according to the corresponding state.

[0030] It should be noted that the harmonic content analysis results of the branch line include abnormal, suspected abnormal and normal.

[0031] Specifically, when the harmonic content analysis result is normal, it is determined that the harmonic content analysis result meets the requirement.

[0032] It is understandable that when the harmonic content analysis result of the branch line does not meet the requirements, it is determined that the branch line cannot be used for the measurement instrument.

[0033] It should also be noted that the method for determining the harmonic content analysis result of the branch line is: Based on the usage data of different harmonic abnormal equipment combinations, determine the usage time of the harmonic abnormal equipment combinations in different time periods, and judge whether the usage time in different time periods is greater than the preset usage time. If so, determine that the harmonic content analysis result of the branch line does not meet the requirements, if not, proceed to the next step; Obtain the usage time of the harmonic abnormal device combination in different time periods, and determine the harmonic device abnormal values ​​in different time periods in combination with the harmonic content abnormal values ​​of different harmonic abnormal device combinations, and judge whether the number of time periods in which the harmonic device abnormal values ​​do not meet the requirements meets the requirements. If not, determine that the harmonic content analysis result of the branch line does not meet the requirements. If so, proceed to the next step; Based on the usage data of different harmonic abnormal device combinations, the usage duration of different harmonic abnormal device combinations in different time periods is determined, and the usage duration in different time periods is used to determine the screening usage time periods, and the usage discreteness of the harmonic abnormal device combinations is determined based on the number proportion of the screening usage time periods; Obtain the cumulative usage time of the harmonic abnormal device combination, and determine the frequency of use of the harmonic abnormal device based on the cumulative usage time of the harmonic abnormal device combination, determine the device weight values ​​of different harmonic abnormal combinations according to the weights of the frequency of use and the discrete degree of use, and judge whether there is an abnormal combination whose device weight value does not meet the requirements. If so, determine that the harmonic content analysis result of the branch line does not meet the requirements, if not, proceed to the next step; The harmonic content abnormality values ​​and device weight values ​​of different harmonic abnormal device combinations are used to determine the harmonic abnormality degree value of the branch line, and the harmonic content analysis result of the branch line is determined based on the harmonic abnormality degree value.

[0034] S3 determines the harmonic abnormality probability of different time periods based on the usage data of the harmonic abnormality equipment combination in different time periods, and uses the harmonic abnormality probability to locate the measurement time period of the measuring instrument; Specifically, Figure 3 As shown, the method for determining the harmonic abnormality probability is: Determine the accumulated usage time of the harmonic abnormality equipment combination in the time period based on the usage data of the harmonic abnormality equipment combination in the time period; Determine the abnormal probability of different harmonic abnormal device combinations in the time period according to the accumulated usage time and the abnormal value of the harmonic content of the harmonic abnormal device combination; The harmonic abnormality probability of the time period is determined by the sum of the combined abnormality probabilities of different harmonic abnormality equipment combinations.

[0035] Further, when the harmonic abnormality probability of the time period is within a preset probability interval, the time period is determined to be a measurement period.

[0036] S4 determines the harmonic measurement analysis duration of the measurement period according to the harmonic abnormality probability of the measurement period, and determines whether the branch circuit can be used for the measurement instrument based on the harmonic measurement result within the harmonic measurement analysis duration.

[0037] It should be noted that the harmonic measurement and analysis duration of the measurement period is determined according to a preset analysis duration corresponding to the harmonic anomaly probability of the measurement period.

[0038] Further, determining whether the branch circuit can be used to perform the measurement instrument includes: Determining harmonic measurement results at different moments within the harmonic measurement analysis time period based on the harmonic measurement results within the harmonic measurement analysis time period; Determine the harmonic abnormal moments within the harmonic measurement and analysis duration according to the harmonic measurement results at different times, and determine the basic abnormal value within the harmonic measurement and analysis duration according to the number ratio of the harmonic abnormal moments; Based on the number of intervals between different harmonic abnormal moments, the maximum duration of the harmonic abnormal period within the harmonic measurement and analysis duration is determined, and based on the maximum duration, the aggregated abnormal value within the harmonic measurement and analysis duration is determined; The sum of the basic abnormal value and the aggregated abnormal value is used to determine the harmonic monitoring abnormal value within the harmonic measurement and analysis time period, and whether the branch line can be used for the measurement instrument is determined according to the harmonic monitoring abnormal value.

[0039] It should be further explained that when the harmonic monitoring abnormal value is not within the preset abnormal range, it is determined that the branch circuit cannot be used for the measurement instrument.

[0040] It can also be understood that determining whether the branch circuit can be used to perform the measurement instrument includes steps S41-S43, which are specifically: S41 determines the harmonic measurement results at different moments in the harmonic measurement and analysis time period based on the harmonic measurement results in the harmonic measurement and analysis time period, and determines the harmonic abnormal moment in the harmonic measurement and analysis time period according to the harmonic measurement results at different moments; Optionally, the above step S41 includes the following contents: Based on the harmonic measurement results within the harmonic measurement and analysis time period, determine the harmonic measurement results at different times within the harmonic measurement and analysis time period, determine the harmonic abnormal moments within the harmonic measurement and analysis time period according to the harmonic measurement results at different times, and judge whether the number of the harmonic abnormal moments meets the requirements. If so, enter step S42; if not, determine that the branch circuit cannot be used for the measurement instrument.

[0041] S42 divides the harmonic abnormal moments into different harmonic abnormal time periods based on the number of intervals between different adjacent harmonic abnormal moments, obtains the number of harmonic abnormal time periods within the harmonic measurement and analysis duration, and determines the aggregated abnormal value within the harmonic measurement and analysis duration in combination with the duration of different harmonic abnormal time periods; Optionally, the above step S42 includes steps S421-S423, which are specifically: S421 determines whether the number of intervals between different adjacent harmonic abnormal moments is greater than the preset number of moments, if so, proceeds to step S43, if not, proceeds to the next step; S422: dividing the harmonic abnormal moments into different harmonic abnormal time periods based on the number of intervals between different adjacent harmonic abnormal moments, and judging whether the maximum duration of the harmonic abnormal time period meets the requirement, if so, proceeding to the next step, if not, determining that the branch circuit cannot be used for the measurement instrument; S23 obtains the number of harmonic abnormality time periods within the harmonic measurement and analysis time period, and determines the aggregated abnormality value within the harmonic measurement and analysis time period in combination with the duration of different harmonic abnormality time periods, and judges whether the aggregated abnormality value within the harmonic measurement and analysis time period meets the requirements. If so, enters step S43; if not, it is determined that the branch circuit cannot be used for the measurement instrument.

[0042] S43 determines the basic abnormal value within the harmonic measurement and analysis time period based on the proportion of the number of harmonic abnormal moments, determines the harmonic monitoring abnormal value within the harmonic measurement and analysis time period using the sum of the basic abnormal value and the aggregated abnormal value, and determines whether the branch circuit can be used for measuring instrument use based on the harmonic monitoring abnormal value. Example 2

[0043] On the other hand, an embodiment of the present application provides a power grid harmonic content measurement and analysis system, which adopts the above-mentioned power grid harmonic content measurement and analysis method, specifically including: Abnormal combination determination module, harmonic content assessment module, measurement period positioning module, assessment result output module; The abnormal combination determination module is responsible for dividing the power supply line into multiple branch lines, using the harmonic monitoring equipment to determine the harmonic content data of the branch lines at different times, and combining the start-up data of the electrical equipment of the branch lines at different times to determine the abnormal values ​​of the harmonic content of different electrical equipment combinations, and determining the abnormal harmonic equipment combination in the electrical equipment combination based on the abnormal values ​​of the harmonic content; The harmonic content evaluation module is responsible for determining the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determining the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations; The measurement period positioning module is responsible for determining the harmonic anomaly probability of different time periods based on the usage data of the harmonic abnormal device combination in different time periods, and positioning the measurement period of the measuring instrument using the harmonic anomaly probability; The evaluation result output module is responsible for determining the harmonic measurement analysis duration of the measurement period based on the harmonic abnormality probability of the measurement period, and determining whether the branch circuit can be used for measuring instrument use based on the harmonic measurement results within the harmonic measurement analysis duration.

[0044] The above step S12 includes steps S121-S123, which are specifically: S121 determines whether the proportion of the time period in which the harmonic content does not meet the requirement in the matching start period meets the requirement, if so, proceeds to the next step, if not, proceeds to step S13; S122 divides the matching start-up period into different power intervals based on the transmission power of the matching start-up period, determines the power interval of the period where the harmonic content does not meet the requirements based on the harmonic content data of the different power intervals, and uses it as the harmonic content exceeding power interval, and determines whether there is a harmonic content exceeding power interval whose duration ratio of the period where the harmonic content does not meet the requirements does not meet the requirements, if so, proceeds to the next step, if not, determines that the electrical equipment combination does not belong to the harmonic abnormal equipment combination; S123 determines the harmonic abnormal values ​​of different power intervals based on the harmonic content at different harmonic frequencies in different power intervals, and determines whether there is a power interval where the harmonic abnormal value does not meet the requirements. If so, enter step S13; if not, determine that the electrical equipment combination does not belong to the harmonic abnormal equipment combination.

[0045] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0046] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0047] The above description is only one or more embodiments of this specification and is not intended to limit this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included in the scope of the claims of this specification.

Claims

1. A method for measuring and analyzing harmonic content in a power grid, It is characterized in that Specifically include: Divide the power supply line into multiple branch lines, use harmonic monitoring equipment to determine the harmonic content data of the branch lines at different times, and determine the abnormal harmonic content values ​​of different combinations of electrical equipment in combination with the start-up data of electrical equipment on the branch lines at different times, and determine the abnormal harmonic device combination in the electrical equipment combination based on the abnormal harmonic content values; Determine the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determine the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations, and when the harmonic content analysis result meets the requirements, proceed to the next step; Based on the usage data of the harmonic abnormal equipment combination in different time periods, the harmonic abnormality probability in different time periods is determined, and the measurement time period of the measuring instrument is located using the harmonic abnormality probability; The harmonic measurement analysis duration of the measurement period is determined based on the harmonic abnormality probability of the measurement period, and whether the branch circuit can be used for the measurement instrument is determined based on the harmonic measurement result within the harmonic measurement analysis duration.

2. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that Divide the power supply line into multiple branch lines, including: According to the tapping data of the power supply line in different power distribution devices, the power supply line is divided into a plurality of independent branch lines.

3. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that The harmonic content data includes the harmonic content of the power supply line at different harmonic frequencies.

4. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that The method for determining the abnormal value of the harmonic content of the electrical equipment combination is: Determining the matching start-up time period of the combination of electrical devices based on the start-up data of the electrical devices at different times; Dividing the matching on period into different power intervals based on the delivered power of the matching on period, and determining the harmonic abnormality values ​​of the different power intervals based on the harmonic contents at different harmonic frequencies of the different power intervals; The weight values ​​of different power intervals are determined by the proportion of operating time in different power intervals, the weight values ​​of different power intervals and harmonic anomaly values ​​are used to determine the weight sum of harmonic anomaly values, and the weight sum of the harmonic anomaly values ​​is used as the harmonic content anomaly value of the electrical equipment combination.

5. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 4, It is characterized in that When the abnormal value of the harmonic content of the electrical equipment combination is not within the preset abnormal value interval, the electrical equipment combination is determined to be a harmonic abnormal equipment combination.

6. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that The method for determining the harmonic content analysis result of the branch line is: Based on the usage data of different harmonic abnormal device combinations, the usage duration of different harmonic abnormal device combinations in different time periods is determined, and the usage duration in different time periods is used to determine the screening usage time periods, and the usage discreteness of the harmonic abnormal device combinations is determined based on the number proportion of the screening usage time periods; Obtaining the cumulative usage time of the harmonic abnormal device combination, and determining the frequency of use of the harmonic abnormal device based on the cumulative usage time of the harmonic abnormal device combination; The equipment weight values ​​of different harmonic abnormality combinations are determined according to the weights of the frequency of use and the discreteness of use, and the harmonic abnormality degree value of the branch line is determined in combination with the harmonic content abnormality values ​​of different harmonic abnormality equipment combinations; the harmonic content analysis result of the branch line is determined based on the harmonic abnormality degree value.

7. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 6, It is characterized in that Determining the harmonic content analysis result of the branch line based on the harmonic abnormality value specifically includes: The harmonic abnormality level value is used to determine the corresponding state of the branch line under the harmonic abnormality level, and the harmonic content analysis result of the branch line is determined according to the corresponding state.

8. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that The harmonic content analysis results of the branch line include abnormal, suspected abnormal and normal; Using the frequency and discreteness weights to determine the equipment weight values ​​of different harmonic abnormal combinations, it is determined whether there is an abnormal combination whose equipment weight value does not meet the requirements. If so, it is determined that the harmonic content analysis result of the branch line does not meet the requirements. If not, proceed to the next step; The harmonic content abnormality values ​​and device weight values ​​of different harmonic abnormal device combinations are used to determine the harmonic abnormality degree value of the branch line, and the harmonic content analysis result of the branch line is determined based on the harmonic abnormality degree value.

9. A method for measuring and analyzing harmonic content in a power grid as claimed in claim 1, It is characterized in that The harmonic measurement analysis duration of the measurement period is determined according to a preset analysis duration corresponding to the harmonic abnormality probability of the measurement period.

10. A power grid harmonic content measurement and analysis system, using a power grid harmonic content measurement and analysis method according to any one of claims 1 to 9, It is characterized in that Specifically include: Abnormal combination determination module, harmonic content assessment module, measurement period positioning module, assessment result output module; The abnormal combination determination module is responsible for dividing the power supply line into multiple branch lines, using the harmonic monitoring equipment to determine the harmonic content data of the branch lines at different times, and combining the start-up data of the electrical equipment of the branch lines at different times to determine the abnormal values ​​of the harmonic content of different electrical equipment combinations, and determining the abnormal harmonic equipment combination in the electrical equipment combination based on the abnormal values ​​of the harmonic content; The harmonic content evaluation module is responsible for determining the usage data of the harmonic abnormal device combination by using the usage record of the harmonic abnormal device combination, and determining the harmonic content analysis result of the branch line according to the usage data and the harmonic content abnormal values ​​of different harmonic abnormal device combinations; The measurement period positioning module is responsible for determining the harmonic anomaly probability of different time periods based on the usage data of the harmonic abnormal device combination in different time periods, and using the harmonic anomaly probability to locate the measurement period of the measuring instrument; The evaluation result output module is responsible for determining the harmonic measurement analysis duration of the measurement period based on the harmonic abnormality probability of the measurement period, and determining whether the branch circuit can be used for measuring instrument use based on the harmonic measurement results within the harmonic measurement analysis duration.

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