Photovoltaic inverter electrical performance detection method and system

Abstract

The present invention relates to the field of data processing technology, and in particular to a photovoltaic inverter electrical performance detection method and system, including: obtaining the degree of prominence of its own harmonic performance in each harmonic time period; obtaining the authenticity of the harmonic impact in each harmonic time period according to the degree of prominence of its own harmonic performance and the overall response sensitivity of environmental influence to different types of electrical performance data; obtaining the instability tendency of photovoltaic inverter components in each harmonic time period; obtaining the severity of harmonics caused by the components themselves in each harmonic time period; and performing electrical performance detection on the photovoltaic inverter based on the severity of harmonics caused by the components themselves in the harmonic time period. The present invention improves the accuracy of the electrical performance detection result of the photovoltaic inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a method and system for detecting electrical performance of a photovoltaic inverter. Background Art

[0002] A photovoltaic inverter (PV inverter or solar inverter) is an inverter that converts the variable DC voltage generated by photovoltaic solar panels into high-frequency AC power, which can be fed back to the commercial power transmission system. The photovoltaic inverter is one of the important system balances in the photovoltaic array system and can be used in conjunction with general AC power supply equipment. Currently, various types of sensors are installed on photovoltaic inverter equipment to monitor various detection data of electrical equipment, and the operating status of the electrical equipment is analyzed after the data is analyzed. However, the actual electrical performance monitoring of the photovoltaic inverter may be affected by external environmental factors, such as temperature changes and uneven light. These factors will affect the operating stability of the inverter, resulting in inaccurate or large fluctuations in the monitoring results. At the same time, when analyzing historical waveform data, if the electrical performance is analyzed only based on the waveform changes at a single moment, large errors are likely to occur, resulting in misjudgment of harmonic distortion caused by the influence of the various components of the photovoltaic inverter itself, which ultimately reduces the accuracy of the detection of the inverter's electrical performance. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method and system for detecting electrical performance of a photovoltaic inverter.

[0004] An embodiment of the present invention provides a method for detecting electrical performance of a photovoltaic inverter, the method comprising the following steps:

[0005] Acquire several electrical performance data sequences and several environmental impact data sequences of the photovoltaic inverter, as well as several harmonic time periods and the harmonic order of each harmonic time period;

[0006] According to the influence of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained;

[0007] According to the duration length and harmonic order of each harmonic time period, the degree of prominence of its own harmonic performance in each harmonic time period is obtained; according to the degree of prominence of its own harmonic performance and the overall response sensitivity of environmental impact to different types of electrical performance data, the authenticity of the harmonic impact of each harmonic time period is obtained; according to the difference in the time interval and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time periods, the instability tendency of the photovoltaic inverter components in each harmonic time period is obtained; through the instability tendency of the photovoltaic inverter components in each harmonic time period and the degree of prominence of their own harmonic performance, the severity of the harmonics caused by the components themselves in each harmonic time period is obtained;

[0008] The electrical performance of the photovoltaic inverter is tested based on the severity of the harmonics caused by the components themselves during the harmonic time period.

[0009] Preferably, the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained according to the impact of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, including the specific method of:

[0010] According to the correlation between each environmental impact data and each electrical performance data in each harmonic time period, the correlation between each electrical performance data sequence and each environmental impact data sequence in each harmonic time period is obtained;

[0011] Obtain the impact weight of each environmental impact data according to the theoretical normal operating allowable range and precision unit of each environmental impact data;

[0012] The first In the harmonic time period The electrical performance data series and The correlation between the environmental impact data series and the The product of the impact weights of the environmental impact data is recorded as In the harmonic time period Environmental impact data for the The response sensitivity factor of the electrical performance data is All environmental impact data within the harmonic time period are The cumulative sum of the response sensitivity factors of the various electrical performance data is used as the The environmental impact during the harmonic time period has an impact on the The overall response sensitivity of various electrical performance data.

[0013] Preferably, the specific method of obtaining the correlation between each electrical performance data sequence and each environmental impact data sequence in each harmonic time period includes:

[0014] For harmonic time period, The first The sequence of electrical performance data is recorded as In the harmonic time period kind of electrical performance data sequence; The first The sequence of environmental impact data is recorded as In the harmonic time period environmental impact data series; In the harmonic time period The electrical performance data series and The absolute value of the Pearson correlation coefficient between the environmental impact data series is taken as the In the harmonic time period The electrical performance data series and This environment affects the correlation between data series.

[0015] Preferably, the specific method for obtaining the impact weight of each environmental impact data is:

[0016] The first The maximum value of the theoretical normal operation allowable range of the environmental impact data is The difference between the minimum values ​​of the theoretical normal operation allowable range of the environmental impact data is recorded as the first difference; The reciprocal of the product of the precision unit of the environmental impact data and the first difference is taken as the The impact weight of the environmental impact data.

[0017] Preferably, the method of obtaining the degree of prominence of the harmonic performance of each harmonic time period according to the duration length and harmonic order of each harmonic time period includes the following specific methods:

[0018] The first The total number of all acquisition moments in the harmonic time period is The product of the harmonic orders of the harmonic time periods is taken as the The degree of prominence of the own harmonics in each harmonic time period.

[0019] Preferably, the authenticity of the harmonic impact in each harmonic time period is obtained according to the prominence of the harmonic performance itself and the overall response sensitivity of the environmental impact to different types of electrical performance data, including the specific method of:

[0020] The first The degree of prominence of the self-harmonics in each harmonic time period is similar to that in the The ratio of the average values ​​of the overall response sensitivity of all kinds of electrical performance data to the environmental impact in the harmonic time period is taken as the first The harmonics of each harmonic time period affect the authenticity.

[0021] Preferably, the specific method for obtaining the instability tendency of the photovoltaic inverter element in each harmonic time period according to the difference in the time interval between each harmonic time period and the authenticity of the harmonic impact with its adjacent harmonic time period is:

[0022] The first The authenticity of the harmonic impact of the first harmonic time period is The absolute value of the difference between the authenticity of the harmonic influence of the left adjacent harmonic time period of the harmonic time period is recorded as the first absolute value of the difference; The ratio of the number of all acquisition moments between the first harmonic time period and its left adjacent harmonic time period to the absolute value of the first difference is recorded as the first ratio; The authenticity of the harmonic impact of the first harmonic time period is The absolute value of the difference between the authenticity of the harmonic influence of the right adjacent harmonic time period of the first harmonic time period is recorded as the second absolute value of the difference; The ratio between the number of all acquisition moments between the first harmonic time period and its right adjacent harmonic time period and the absolute value of the second difference is recorded as the first ratio; the sum of the first ratio and the second ratio is recorded as the second ratio. The unstable tendency of PV inverter components during the harmonic time period.

[0023] Preferably, the severity of harmonics caused by the components themselves in each harmonic time period is obtained by the unstable tendency of the photovoltaic inverter components and the degree of prominence of their own harmonic performance in each harmonic time period, including the specific method of:

[0024] The first The unstable tendency of photovoltaic inverter components in the first harmonic period is related to the The normalized value of the product of the prominence of the harmonic performance of the harmonic time period is taken as the The severity of the harmonics caused by the component itself during the harmonic time period.

[0025] Preferably, the electrical performance detection of the photovoltaic inverter based on the severity of harmonics caused by the components themselves within the harmonic time period includes the following specific methods:

[0026] Input all kinds of electrical performance data sequences of the photovoltaic inverter into the trained neural network to obtain the initial electrical performance score of the photovoltaic inverter;

[0027] The difference between 1 and the average value of the harmonic severity caused by the component itself in all harmonic time periods is recorded as the score weight difference; the product of the initial electrical performance score of the photovoltaic inverter and the score weight difference is used as the final electrical performance score of the photovoltaic inverter;

[0028] Preset a threshold parameter , if the final electrical performance score of the PV inverter is greater than or equal to the threshold parameter , the electrical performance of the photovoltaic inverter is recorded as qualified.

[0029] The present invention also proposes a photovoltaic inverter electrical performance detection system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the steps of the photovoltaic inverter electrical performance detection method when executing the computer program.

[0030] The beneficial effects of the technical solution of the present invention are as follows: the present invention obtains the degree of prominence of the harmonic performance of each harmonic time period according to the duration length and harmonic order of each harmonic time period; obtains the authenticity of the harmonic impact of each harmonic time period according to the degree of prominence of the harmonic performance of the harmonic performance and the overall response sensitivity of environmental influence to different types of electrical performance data; obtains the instability tendency of the photovoltaic inverter element in each harmonic time period according to the difference in the time interval and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time period; obtains the severity of the harmonics caused by the element itself in each harmonic time period through the instability tendency and the degree of prominence of the harmonic performance of the photovoltaic inverter element in each harmonic time period; performs electrical performance detection on the photovoltaic inverter based on the severity of the harmonics caused by the element itself in the harmonic time period; thereby eliminating the influence of the external environment on the electrical performance evaluation, avoiding the large error caused by analyzing the electrical performance of the photovoltaic inverter only according to the waveform change at a single moment, and improving the accuracy of the electrical performance detection result of the photovoltaic inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0032] Figure 1 A flow chart of the steps of a photovoltaic inverter electrical performance detection method of the present invention;

[0033] Figure 2 The present invention is a characteristic relationship flow chart of the electrical performance detection of a photovoltaic inverter. DETAILED DESCRIPTION

[0034] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a photovoltaic inverter electrical performance detection method and system proposed by the present invention, its specific implementation, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0036] The specific scheme of a photovoltaic inverter electrical performance detection method and system provided by the present invention is described in detail below with reference to the accompanying drawings.

[0037] See also Figure 1 , which shows a flow chart of a method for detecting the electrical performance of a photovoltaic inverter provided by an embodiment of the present invention, the method comprising the following steps:

[0038] Step S001: Acquire several electrical performance data sequences and several environmental impact data sequences of a photovoltaic inverter, as well as several harmonic time periods and the harmonic order of each harmonic time period.

[0039] It should be noted that the electrical performance of a photovoltaic inverter refers to the inverter's ability to convert and output electrical energy in a photovoltaic system and its matching with the photovoltaic array. In the process of testing the electrical performance, it is necessary to make an overall judgment on the actual electrical performance based on harmonic testing to eliminate possible faults. The output voltage harmonics of a photovoltaic inverter refer to the harmonic components contained in the output voltage whose frequencies are multiples of the fundamental frequency. The output voltage harmonics of a photovoltaic inverter can be measured and analyzed by professional testing equipment such as a harmonic analyzer or a power quality analyzer. Voltage harmonics can have an adverse effect on power grids and other power equipment. For the output voltage of a photovoltaic inverter, it is generally required that its harmonic content be lower than the limit specified by specific standards or specifications. These standards or specifications usually specify limits for different harmonic orders to ensure voltage quality and system stability.

[0040] Specifically, it is necessary to first collect several electrical performance data sequences and several environmental impact data sequences of the photovoltaic inverter, as well as several harmonic time periods and the harmonic order of each harmonic time period. The specific process is as follows:

[0041] Every 1 minute is a collection moment. Each time, different types of sensors installed on key equipment such as photovoltaic modules, inverters, and combiner boxes are used to collect the voltage data, current data, power generation data, power generation data, temperature data, and light intensity data of the photovoltaic inverter. The data is collected for a total of 24 hours. The four-dimensional data of the voltage data, current data, power generation data, and power generation data of the photovoltaic inverter at all collection moments are taken as the electrical performance data sequence. The two-dimensional data of the temperature data and light intensity data of the photovoltaic inverter at all collection moments are taken as the environmental impact data sequence.

[0042] The voltage data of the photovoltaic inverter at all acquisition moments are subjected to fast Fourier transform, and the time domain signal is converted into the frequency domain signal to obtain the voltage frequency domain signal of the photovoltaic inverter; in the voltage frequency domain signal of the photovoltaic inverter, several time periods with harmonics and the harmonic order of each time period are obtained through harmonic analysis; each time period with harmonics is recorded as a harmonic time period.

[0043] Among them, Fourier transform and harmonic wave analysis are existing technologies, and will not be described in detail in this embodiment.

[0044] So far, several electrical performance data sequences and several environmental impact data sequences of the photovoltaic inverter, as well as several harmonic time periods and the harmonic order of each harmonic time period are obtained through the above method.

[0045] Step S002: according to the influence of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained.

[0046] It should be noted that harmonics refer to the fluctuation components contained in the periodic fluctuation signal within a period of time, which are integer multiples of the fundamental frequency. This phenomenon is affected by the performance of the component itself and external environmental factors. The actual electrical performance monitoring of photovoltaic inverters may be interfered by external environmental factors, such as temperature changes and uneven light. These factors may affect the operating stability of the inverter, that is, directly affect the components or power of the photovoltaic inverter's related electrical performance, resulting in inaccurate or large fluctuations in monitoring results. Therefore, it is necessary to judge the impact of environmental factors on photovoltaic inverters.

[0047] Preferably, in some implementations of the embodiments of the present invention, according to the impact of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, a specific method for obtaining the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is:

[0048] It should be noted that in a photovoltaic power generation system, electrical performance data is data information that can directly reflect the actual power generation situation of the power generation system, and environmental impact data is data information that can interfere with the power generation efficiency of the photovoltaic power generation system. To evaluate the electrical performance of a photovoltaic power generation system, it is necessary to analyze the power generation level of the current electrical performance data under the influence of the current various impact data. Therefore, it is first necessary to analyze the impact of different types of environmental impact data on each type of electrical performance data.

[0049] Preferably, for harmonic time period, The first The sequence of electrical performance data is recorded as In the harmonic time period kind of electrical performance data sequence; The first The sequence of environmental impact data is recorded as In the harmonic time period environmental impact data series; In the harmonic time period The electrical performance data series and The Pearson correlation coefficient between the environmental impact data series is used as the In the harmonic time period The electrical performance data series and The correlation between the environmental impact data series;

[0050] It should be noted that, due to the differences in the required adjustment range and precise units of rated parameters during the measurement and acquisition of different environmental impact data, for any kind of environmental impact data, the smaller the theoretical normal operation allowable range on the photovoltaic inverter and the greater the accuracy requirement, that is, the smaller the precision unit, the greater the possibility of changes in the photovoltaic inverter itself during operation.

[0051] Preferably, according to the theoretical normal operation allowable range and precision unit of each environmental impact data, the specific formula for obtaining the impact weight of each environmental impact data is:

[0052]

[0053] In the formula, Indicates The impact weight of the environmental impact data; Indicates The maximum value of the theoretical normal operating allowable range of the environmental impact data; Indicates The minimum value of the theoretical normal operating allowable range of the environmental impact data; Indicates The environment affects the precision of the data.

[0054] Preferably, according to the influence weight of each environmental impact data and the correlation between each environmental impact data and each electrical performance data, a specific formula for obtaining the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is:

[0055]

[0056] In the formula, Indicated in The environmental impact during the harmonic time period has an impact on the The overall response sensitivity of the electrical performance data; Indicates The impact weight of the environmental impact data; Indicates In the harmonic time period The electrical performance data series and The correlation between the environmental impact data series; Indicates taking the absolute value.

[0057] It should be noted that The larger the value, the The greater the possibility that the electrical performance data is affected by the external environment, the higher its overall response sensitivity.

[0058] So far, the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained through the above method.

[0059] Step S003: According to the duration length and harmonic order of each harmonic time period, the degree of prominence of the own harmonic performance of each harmonic time period is obtained; according to the degree of prominence of the own harmonic performance and the overall response sensitivity of environmental influences to different types of electrical performance data, the authenticity of the harmonic impact of each harmonic time period is obtained; according to the difference in the time interval and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time periods, the instability tendency of the photovoltaic inverter components in each harmonic time period is obtained; through the instability tendency of the photovoltaic inverter components in each harmonic time period and the degree of prominence of their own harmonic performance, the severity of the harmonics caused by the components themselves in each harmonic time period is obtained.

[0060] It should be noted that the generation of harmonics does not occur at a certain moment, but is the distortion of the voltage waveform generated in a continuous period of time. Usually, these distortions are integer multiples of the fundamental wave. Therefore, if the electrical performance is analyzed only based on the waveform changes at a single moment, it is easy to produce large errors, resulting in misjudgment of the harmonic distortion caused by the influence of the various components of the photovoltaic inverter itself, which ultimately reduces the accuracy of the detection of the inverter's electrical performance. Therefore, it is necessary to judge the instability tendency of photovoltaic inverter components through the performance of electrical performance data in each harmonic time period and the relationship between it and other external environments.

[0061] Preferably, in some implementations of the embodiments of the present invention, the specific method for obtaining the instability tendency of the photovoltaic inverter element in each harmonic time period is:

[0062] It should be noted that when harmonics are generated, they usually manifest as frequency changes over a period of time; when the frequency order of the harmonics is higher and the duration is longer, it indicates that the possibility of abnormality in the photovoltaic inverter is higher in the current period of time, and the impact on electrical performance is greater; therefore, according to the The duration length of the harmonic time period and the harmonic order are obtained. The calculation method for the prominence of the self-harmonic performance in a harmonic time period is:

[0063] Preferably, the The total number of all acquisition moments in the harmonic time period is The product of the harmonic orders of the harmonic time periods is taken as the The prominence of the own harmonics in each harmonic time period;

[0064] The specific formula is:

[0065]

[0066] In the formula, Indicates The prominence of the own harmonics in each harmonic time period; Indicates The total number of all acquisition moments in a harmonic time period; Indicates The harmonic order of each harmonic time period.

[0067] It should be noted that due to the particularity of harmonics, a fixed harmonic order is usually guaranteed within the same time period. This fixed harmonic performance is usually caused by problems with the original components themselves. When the external environment interferes, the harmonic order will change within a continuous time period, and the impact of external conditions on the inverter reflects that the impact threshold required for harmonic distortion is different, which will lead to misjudgment of the actual cause of the harmonic distortion of the current inverter. The overall response sensitivity of environmental impact to different types of electrical performance data can be used to obtain the authenticity of the harmonic impact of each harmonic time period.

[0068] Preferably, obtain The calculation formula for the authenticity of the harmonic impact of a harmonic time period is:

[0069]

[0070] In the formula, Indicates The authenticity of harmonic effects in each harmonic time period; Indicates The prominence of the own harmonics in each harmonic time period; Indicates The average value of the overall response sensitivity of environmental impact to all kinds of electrical performance data within a harmonic time period.

[0071] It should be noted that when there is a difference in order between any two harmonic time periods, the greater the difference in the time interval between the two, and the smaller the fluctuation of environmental factors affected by external factors, the greater the possibility that the harmonic distortion in the current harmonic time period is generated by the equipment components themselves.

[0072] Preferably, according to the difference in the time interval between each harmonic time period and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time period, a specific formula for obtaining the instability tendency of the photovoltaic inverter element in each harmonic time period is:

[0073]

[0074] In the formula, Indicates The unstable tendency of PV inverter components during each harmonic period; Indicates The number of all acquisition moments between a harmonic time period and its left adjacent harmonic time period; Indicates The authenticity of harmonic effects in each harmonic time period; Indicates The authenticity of the harmonic influence of the left adjacent harmonic time period of a harmonic time period; Indicates The number of all acquisition moments between a harmonic time period and its right adjacent harmonic time period; Indicates The authenticity of the harmonic influence of the right adjacent harmonic time period of a harmonic time period; Indicates taking the absolute value.

[0075] It should be noted that the smaller the difference in the authenticity of the harmonic impact between a harmonic time period and its adjacent harmonic time period is, the greater the possibility of harmonic distortion generated by the equipment components themselves, and the higher the tendency of component instability is. At the same time, the time interval between the harmonic time period and its adjacent harmonic time period is weighted to obtain the instability tendency of the photovoltaic inverter components in the harmonic time period. The larger the value is, the higher the instability tendency of the photovoltaic inverter components in the harmonic time period is.

[0076] Thus, the unstable tendency of the photovoltaic inverter components in each harmonic time period is obtained.

[0077] It should be noted that in the process of testing the actual electrical performance of the photovoltaic inverter, the actual performance of the inverter is usually analyzed based on the total length of time when harmonics occur and the harmonic frequency. In order to avoid interference from the external environment, it is necessary to eliminate the influencing factors caused by the external environment in each harmonic time period, and then build relatively ideal conditions and evaluate the electrical performance. The higher the frequency and the longer the duration, the worse the electrical performance, that is, the more prominent the harmonic performance is, the worse the electrical performance is. The greater the instability tendency of the component, the greater the influence of the original itself in the process of generating harmonics, and vice versa. The greater the influence of the external environment. Therefore, the severity of the harmonics caused by the component itself in each harmonic time period can be obtained through the instability tendency of the photovoltaic inverter component and the degree of its own harmonic performance in each harmonic time period.

[0078] Preferably, in some implementations of the embodiments of the present invention, the specific formula for obtaining the severity of the harmonics caused by the component itself in each harmonic time period is:

[0079]

[0080] In the formula, Indicates The severity of the harmonics caused by the component itself within each harmonic time period; Indicates The unstable tendency of PV inverter components during each harmonic period; Indicates The prominence of the own harmonics in each harmonic time period; represents the linear normalization function.

[0081] So far, the severity of the harmonics caused by the component itself in each harmonic time period is obtained through the above method.

[0082] Step S004: Performing electrical performance detection on the photovoltaic inverter based on the severity of harmonics caused by the components themselves within the harmonic time period.

[0083] Specifically, all kinds of electrical performance data sequences of the photovoltaic inverter are input into the trained neural network to obtain the initial electrical performance score of the photovoltaic inverter; the neural network Resnet50 used in this embodiment, the method for obtaining the data set for training the neural network is:

[0084] A large number of photovoltaic inverters are collected from all kinds of electrical performance data sequences, and a numerical value between 0 and 1 is used as an initial electrical performance score label, and a label is artificially assigned to each photovoltaic inverter; a large number of photovoltaic inverters and their corresponding labels constitute a data set; the neural network is trained using the data set, and the loss function used in the training process is a cross loss function; the specific training process is a well-known content of the neural network, and this embodiment will not repeat the specific training process.

[0085] Among them, the higher the score, the larger the value of the electrical performance score, which means that the electrical performance of the inverter is better.

[0086] Based on the initial electrical performance score of the PV inverter and the severity of the harmonics caused by the components themselves in each harmonic time period, the calculation formula for obtaining the final electrical performance score of the PV inverter is:

[0087]

[0088] In the formula, Indicates the final electrical performance score of the photovoltaic inverter; Indicates the initial electrical performance rating of the photovoltaic inverter; Indicates the average severity of harmonics caused by the component itself over all harmonic time periods.

[0089] Preset a threshold parameter , wherein this embodiment is based on This example is described as an example, and this embodiment is not specifically limited. Depends on the specific implementation situation;

[0090] If the final electrical performance score of the PV inverter is greater than or equal to the threshold parameter , the electrical performance of the photovoltaic inverter is recorded as qualified.

[0091] See also Figure 2 , which shows a characteristic relationship flow chart of the electrical performance detection of a photovoltaic inverter;

[0092] Through the above steps, a photovoltaic inverter electrical performance detection method is completed.

[0093] The present invention also proposes a photovoltaic inverter electrical performance detection system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, steps S001 to S004 of a photovoltaic inverter electrical performance detection method are implemented.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic inverter electrical performance detection method, characterized in that: The method comprises the following steps: Acquire several electrical performance data sequences and several environmental impact data sequences of the photovoltaic inverter, as well as several harmonic time periods and the harmonic order of each harmonic time period; According to the influence of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, the overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained; According to the duration length and harmonic order of each harmonic time period, the degree of prominence of its own harmonic performance in each harmonic time period is obtained; according to the degree of prominence of its own harmonic performance and the overall response sensitivity of environmental impact to different types of electrical performance data, the authenticity of the harmonic impact of each harmonic time period is obtained; according to the difference in the time interval and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time periods, the instability tendency of the photovoltaic inverter components in each harmonic time period is obtained; through the instability tendency of the photovoltaic inverter components in each harmonic time period and the degree of prominence of their own harmonic performance, the severity of the harmonics caused by the components themselves in each harmonic time period is obtained; Conduct electrical performance testing on photovoltaic inverters based on the severity of harmonics caused by the components themselves during the harmonic time period; The overall response sensitivity of the environmental impact to each electrical performance data in each harmonic time period is obtained according to the impact of the environmental impact data and the correlation between each environmental impact data and each electrical performance data in each harmonic time period, including the specific method of: According to the correlation between each environmental impact data and each electrical performance data in each harmonic time period, the correlation between each electrical performance data sequence and each environmental impact data sequence in each harmonic time period is obtained; Obtain the impact weight of each environmental impact data according to the theoretical normal operating allowable range and precision unit of each environmental impact data; The first In the harmonic time period The electrical performance data series and The correlation between the environmental impact data series and the The product of the impact weights of the environmental impact data is recorded as In the harmonic time period Environmental impact data for the The response sensitivity factor of the electrical performance data is All environmental impact data within the harmonic time period are The cumulative sum of the response sensitivity factors of the various electrical performance data is used as the The environmental impact during the harmonic time period has an impact on the The overall response sensitivity of the electrical performance data; The specific method of obtaining the correlation between each electrical performance data sequence and each environmental impact data sequence in each harmonic time period includes: For harmonic time period, The first The sequence of electrical performance data is recorded as In the harmonic time period kind of electrical performance data sequence; The first The sequence of environmental impact data is recorded as In the harmonic time period environmental impact data series; In the harmonic time period The electrical performance data series and The absolute value of the Pearson correlation coefficient between the environmental impact data series is taken as the In the harmonic time period The electrical performance data series and The correlation between the environmental impact data series; The specific method for obtaining the impact weight of each environmental impact data is: The first The maximum value of the theoretical normal operation allowable range of the environmental impact data is The difference between the minimum values ​​of the theoretical normal operation allowable range of the environmental impact data is recorded as the first difference; The reciprocal of the product of the precision unit of the environmental impact data and the first difference is taken as the The impact weight of the environmental impact data; The specific method of obtaining the prominence of the harmonic performance of each harmonic time period according to the duration length and harmonic order of each harmonic time period is as follows: The first The total number of all acquisition moments in the harmonic time period is The product of the harmonic orders of the harmonic time periods is taken as the The prominence of the own harmonics in each harmonic time period; The authenticity of the harmonic impact in each harmonic time period is obtained according to the prominence of the harmonic performance and the overall response sensitivity of the environmental impact to different types of electrical performance data, including the specific method of: The first The degree of prominence of the self-harmonics in each harmonic time period is similar to that in the The ratio of the average values ​​of the overall response sensitivity of all kinds of electrical performance data to the environmental impact in the harmonic time period is taken as the first The authenticity of harmonic effects in each harmonic time period; The specific method for obtaining the instability tendency of the photovoltaic inverter element in each harmonic time period according to the difference in the time interval between each harmonic time period and the authenticity of the harmonic impact between each harmonic time period and its adjacent harmonic time period is: The first The authenticity of the harmonic impact of the first harmonic time period is The absolute value of the difference between the authenticity of the harmonic influence of the left adjacent harmonic time period of the harmonic time period is recorded as the first absolute value of the difference; The ratio of the number of all acquisition moments between the first harmonic time period and its left adjacent harmonic time period to the absolute value of the first difference is recorded as the first ratio; The authenticity of the harmonic impact of the first harmonic time period is The absolute value of the difference between the authenticity of the harmonic influence of the right adjacent harmonic time period of the first harmonic time period is recorded as the second absolute value of the difference; The ratio between the number of all acquisition moments between the first harmonic time period and its right adjacent harmonic time period and the absolute value of the second difference is recorded as the second ratio; the sum of the first ratio and the second ratio is recorded as the first The unstable tendency of PV inverter components during each harmonic period; The method of obtaining the severity of harmonics caused by the components themselves in each harmonic time period by the unstable tendency of the photovoltaic inverter components and the prominence of their own harmonic performance in each harmonic time period includes the following specific methods: The first The unstable tendency of photovoltaic inverter components in the first harmonic period is related to the The normalized value of the product of the prominence of the harmonic performance of the harmonic time period is taken as the The severity of the harmonics caused by the component itself within each harmonic time period; The electrical performance detection of the photovoltaic inverter based on the severity of harmonics caused by the components themselves during the harmonic time period includes the following specific methods: Input all kinds of electrical performance data sequences of the photovoltaic inverter into the trained neural network to obtain the initial electrical performance score of the photovoltaic inverter; The difference between 1 and the average value of the harmonic severity caused by the component itself in all harmonic time periods is recorded as the score weight difference; the product of the initial electrical performance score of the photovoltaic inverter and the score weight difference is used as the final electrical performance score of the photovoltaic inverter; Preset a threshold parameter , if the final electrical performance score of the PV inverter is greater than or equal to the threshold parameter , the electrical performance of the photovoltaic inverter is recorded as qualified.

2. A photovoltaic inverter electrical performance detection system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the photovoltaic inverter electrical performance detection method as claimed in claim 1 are implemented.

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