Photovoltaic field equipment energy efficiency evaluation system and method

Abstract

The present invention discloses a photovoltaic station equipment energy efficiency evaluation system and method, and relates to the technical field of photovoltaic stations. The system of the present invention comprises a conversion efficiency monitoring module, a power point tracking analysis module, a harmonic distortion analysis module, an equipment energy efficiency evaluation module and an early warning terminal. By analyzing the conversion efficiency between the input electric energy and the output electric energy of each inverter corresponding to the photovoltaic station, the maximum power point tracking performance corresponding to each inverter under various sunshine conditions of the photovoltaic station is monitored, and the current waveform data of each inverter corresponding to the photovoltaic station is monitored, so as to perform analysis and synthesis, and then obtain the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station, judge and obtain the energy efficiency status of each inverter corresponding to the photovoltaic station, realize real-time monitoring of the operating status of each inverter equipment corresponding to the photovoltaic station, understand the performance and energy efficiency performance of the inverter equipment during operation, and discover potential problems and risks in time.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic stations, and in particular to a photovoltaic station equipment energy efficiency evaluation system and method. Background Art

[0002] Electricity is indispensable in our daily life, and the normal operation of the energy efficiency of the corresponding equipment in photovoltaic stations is an important support for photovoltaic power generation. Therefore, it is necessary to analyze the energy efficiency of the corresponding equipment in photovoltaic stations in order to promptly discover abnormal conditions of the equipment, implement timely abnormal equipment maintenance, and ensure the normal operation of photovoltaic stations. Among them, the inverter, as one of the core components in the photovoltaic power generation system, is a key device that converts the direct current generated by photovoltaic modules into alternating current, which directly affects the overall power generation efficiency and energy efficiency of the photovoltaic system. Therefore, it is necessary to analyze the inverter to achieve effective prevention and ensure efficient power generation of photovoltaic stations.

[0003] Prior art, such as a photovoltaic field station equipment energy efficiency evaluation system disclosed in the invention patent application with announcement number CN117709765A, relates to the field of photovoltaic field station equipment technology, including a data acquisition module, a data processing and analysis module, an equipment performance monitoring module and a fault diagnosis module. The present invention not only evaluates the energy efficiency of photovoltaic field station equipment, but also calculates the comprehensive performance score of each photovoltaic field station equipment in detail, and uses the comprehensive performance score of each photovoltaic field station equipment to assist the energy efficiency of the photovoltaic field station equipment to diagnose the fault of the photovoltaic field station equipment through the fault diagnosis module. Compared with the existing photovoltaic field station equipment energy efficiency evaluation system, the fault evaluation result is more accurate, so that the equipment fault can be discovered and repaired in time, which greatly reduces the equipment downtime compared with the conventional situation.

[0004] With respect to the above scheme, the applicant of the present invention has found that the above technical problems have at least the following technical problems: the above scheme mainly analyzes the photovoltaic station equipment, but does not conduct an in-depth analysis of the inverter equipment corresponding to the photovoltaic station. The disclosed equipment analysis content is broad in scope and cannot achieve an in-depth evaluation of the equipment energy efficiency. The present scheme conducts an in-depth analysis of each inverter corresponding to the photovoltaic station, and comprehensively monitors each inverter equipment corresponding to the photovoltaic station, thereby achieving an in-depth analysis of the energy efficiency of each inverter in the photovoltaic station, thereby judging the energy efficiency status of each inverter in the photovoltaic station, promptly discovering inverter equipment abnormalities, and ensuring the normal operation of the inverter. Summary of the invention

[0005] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a photovoltaic station equipment energy efficiency evaluation system and method.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a photovoltaic station equipment energy efficiency evaluation system, including: a conversion efficiency monitoring module, which is used to monitor each inverter equipment corresponding to the photovoltaic station, and by monitoring the input power and output power of each inverter corresponding to the photovoltaic station, the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station is analyzed, and the performance coefficient of each inverter corresponding to the photovoltaic station is obtained.

[0007] The power point tracking analysis module is used to monitor the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station.

[0008] The harmonic distortion analysis module is used to monitor the current waveform data of each inverter corresponding to the photovoltaic station. The current waveform data includes harmonic content and waveform distortion, and then analyzes and obtains the suppression performance coefficient of each inverter corresponding to the photovoltaic station.

[0009] The equipment energy efficiency evaluation module is used to analyze and obtain the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station according to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, and determine the energy efficiency status of each inverter corresponding to the photovoltaic station.

[0010] The early warning terminal is used to issue an early warning prompt when the energy efficiency status of a certain inverter device corresponding to the photovoltaic station is abnormal.

[0011] In a second aspect, the present invention provides a method for evaluating the energy efficiency of photovoltaic station equipment, including: step one, conversion efficiency monitoring: monitoring each inverter device corresponding to the photovoltaic station, by monitoring the input power and output power of each inverter corresponding to the photovoltaic station, and then analyzing and obtaining the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station, and then analyzing and obtaining the performance coefficient of each inverter corresponding to the photovoltaic station.

[0012] Step 2: Power point tracking analysis: Monitor the maximum power point tracking performance information of each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station.

[0013] Step 3: Harmonic distortion analysis: monitor the current waveform data of each inverter corresponding to the photovoltaic station, and then analyze and obtain the suppression performance coefficient of each inverter corresponding to the photovoltaic station.

[0014] Step 4: Equipment energy efficiency evaluation: According to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is analyzed and the energy efficiency status of each inverter corresponding to the photovoltaic station is determined.

[0015] Step 5: Early warning: When the energy efficiency status of a certain inverter device in the photovoltaic station is abnormal, an early warning will be issued.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a photovoltaic station equipment energy efficiency evaluation system and method, by analyzing the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station, thereby obtaining its performance coefficient, and monitoring the maximum power point tracking performance of each inverter corresponding to the photovoltaic station under various sunshine conditions, thereby analyzing and obtaining the control capability coefficient of the photovoltaic array output power of each inverter corresponding to the photovoltaic station, and at the same time monitoring the current waveform data of each inverter corresponding to the photovoltaic station, thereby analyzing and obtaining the suppression performance coefficient of each inverter corresponding to the photovoltaic station, and combining the above analysis to obtain the energy efficiency evaluation system of each inverter corresponding to the photovoltaic station. The system can obtain data and determine the energy efficiency status of each inverter corresponding to the photovoltaic station, realize real-time monitoring of the operating status of each inverter equipment corresponding to the photovoltaic station, understand the performance and energy efficiency of the inverter equipment during operation, and promptly discover potential problems and risks, solve the deficiencies in current technology, and improve the overall equipment operation energy efficiency of the photovoltaic station through comprehensive energy efficiency monitoring and analysis of each inverter corresponding to the photovoltaic station, ensure the efficient power generation of the photovoltaic station, reduce the inverter failure rate and maintenance time, reduce the inverter maintenance cost, and improve the power generation efficiency of the photovoltaic station, so as to maximize the use of solar energy resources and provide a solid foundation for the efficient operation and management of the photovoltaic station. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 It is a schematic diagram of the system structure connection of the present invention.

[0019] Figure 2 The present invention is a schematic flow chart of the steps for implementing the method. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 As shown, a photovoltaic station equipment energy efficiency evaluation system includes a conversion efficiency monitoring module, a power point tracking and analysis module, a harmonic distortion analysis module, an equipment energy efficiency evaluation module and an early warning terminal.

[0022] The conversion efficiency monitoring module is connected to the conversion efficiency monitoring module and the early warning terminal respectively, the conversion efficiency monitoring module is connected to the power point tracking and analysis module and the early warning terminal respectively, and the conversion efficiency monitoring module is connected to the harmonic distortion analysis module and the early warning terminal respectively.

[0023] The conversion efficiency monitoring module is used to monitor the inverter devices corresponding to the photovoltaic station. By monitoring the input power and output power of each inverter corresponding to the photovoltaic station, the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station is analyzed, and the performance coefficient of each inverter corresponding to the photovoltaic station is analyzed.

[0024] It should be noted that the sensors include voltage sensors and current sensors. The time scale between the input power and output power of each inverter corresponding to the photovoltaic station is obtained through the power metering instrument. The time scale refers to the time interval or time distribution of a series of events occurring within a certain period of time.

[0025] As an optional implementation mode, the monitoring of the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station, the specific monitoring process is as follows: before monitoring the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station, set the input voltage, input current, output voltage and output current measurement numerical data, and use the sensors installed at the input and output ends of the inverter to collect the data numerical information of the input voltage, input current, output voltage, output current and time scale of each inverter in real time, according to the input voltage and input current, output voltage and output current collected in real time, respectively substitute them into the calculation formula, and then calculate the input power and output power of each inverter corresponding to the photovoltaic station, and at the same time, divide the output power of each inverter corresponding to the photovoltaic station by the input power and multiply it by a percentage, so as to obtain the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station, and record it as wb n .

[0026] As an optional implementation, the analysis obtains the performance coefficient of each inverter corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula Then the performance coefficient bx of the nth inverter corresponding to the photovoltaic station is obtained by analysis: n , n is the number of each inverter, n = 1, 2, ....., m, m is any integer greater than 2, wb n is the conversion efficiency between the input power and output power of the nth inverter corresponding to the photovoltaic station, wb′ is the set reference conversion efficiency, cd n It is the time scale between the input power and output power of the nth inverter in the photovoltaic station.

[0027] It should also be noted that the historical conversion efficiency values ​​corresponding to each inverter are obtained from the database, and the historical conversion efficiency values ​​corresponding to each inverter are averaged to obtain the historical average conversion efficiency corresponding to each inverter, which is used as the reference conversion efficiency.

[0028] The power point tracking analysis module is used to monitor the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station.

[0029] It should be noted that the sensor includes a voltage sensor and a current sensor.

[0030] It should also be noted that the voltage and current values ​​of the photovoltaic array at the maximum power it can generate under various sunshine and temperature conditions can be monitored in real time to understand the maximum power point tracking capability of the inverter under various conditions.

[0031] As an optional implementation manner, the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions of the photovoltaic station is monitored, and the specific monitoring process is as follows: setting the demand monitoring data corresponding to each inverter under various sunshine conditions of the photovoltaic station, including the maximum power point tracking speed, the maximum power point accuracy and the maximum power point stability rate, through the sensor installed between the photovoltaic array and the inverter, the output voltage and current of the photovoltaic array are collected in real time, and the collected output voltage and current of the photovoltaic array are substituted into the algorithm to obtain the maximum power point corresponding to each inverter, and then the maximum power point tracking performance information of each inverter after determining the maximum power point is obtained, including the maximum power point tracking speed, the maximum power point accuracy and the maximum power point stability rate, so as to monitor and obtain the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions of the photovoltaic station.

[0032] As an optional implementation, the analysis obtains the control capability coefficient of each inverter of the photovoltaic station corresponding to the photovoltaic array output power. The specific analysis process is as follows: By calculating the formula The control capability coefficient kz of the nth inverter of the photovoltaic station corresponding to the output power of the photovoltaic array is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, u is the number under various sunshine conditions, u=1,2,.....,j, j is any integer greater than 2, cs′ is the set reference maximum power point tracking speed, at′ is the set reference maximum power point accuracy, pq′ is the set reference maximum power point stability rate, cs nj is the maximum power point tracking speed corresponding to the nth inverter under the jth sunshine condition of the photovoltaic station, at nj is the maximum power point accuracy of the nth inverter under the jth sunshine condition of the photovoltaic station, pq nj is the maximum power point stability rate corresponding to the nth inverter under the jth sunshine condition of the PV station, f1, f2, and f3 are the weight factors of the maximum power point tracking speed, the maximum power point accuracy, and the maximum power point stability rate, respectively, 0<f1<1, 0<f2<1, 0<f3<1.

[0033] It should be noted again that the weight factor of the maximum power point tracking speed, the weight factor of the maximum power point accuracy, and the weight factor of the maximum power point stability rate are obtained through the principal component analysis method. The information of the corresponding maximum power point tracking speed, maximum power point accuracy, and maximum power point stability rate is first condensed, and then the corresponding variance explanation rate is obtained, and then divided by the variance explanation rate to obtain the corresponding weight.

[0034] It is important to note again that information condensation refers to condensing multiple analysis items into several key summary indicators, and the variance explanation rate refers to the contribution of each principal component or factor to the overall variance, usually expressed as a percentage, indicating how much information the factor contains about the original data.

[0035] The harmonic distortion analysis module is used to monitor the current waveform data of each inverter corresponding to the photovoltaic station. The current waveform data includes harmonic content and waveform distortion, and then analyzes and obtains the suppression performance coefficient of each inverter corresponding to the photovoltaic station.

[0036] It should be noted that the photovoltaic array is composed of multiple photovoltaic modules, which are used to convert sunlight into electrical energy. The DC power generated by the photovoltaic modules is converted into AC power through the inverter. Harmonics refer to the frequency components that exist at integer multiples of the original fundamental frequency. Each order of harmonics includes second harmonics, third harmonics, fourth harmonics, etc. The amplitude of each order of harmonics indicates the signal strength of each harmonic component, the harmonic frequency indicates the frequency value of the harmonic component, the waveform distortion is an indicator to measure the degree of deformation of the signal waveform, and the harmonic content is the ratio of the energy of each order of harmonic components in the signal to the total signal energy.

[0037] As an optional implementation, the current waveform data of each inverter corresponding to the photovoltaic station is monitored, and the specific monitoring process is as follows: by real-time monitoring the current waveform data of the output corresponding to each inverter of the photovoltaic station, and digitizing the monitored current waveform data, the current waveform signal is converted into a digital signal format, and at the same time, a spectrum analysis algorithm is used to decompose the current waveform signal into components of different frequencies to form a corresponding spectrum diagram, and the amplitude and frequency of each order of harmonics of each inverter are obtained from the spectrum diagram, and the harmonic content corresponding to each inverter is calculated according to the harmonic amplitude data corresponding to each inverter in the spectrum diagram, and the square of the harmonic content corresponding to each inverter is summed, and the square root is taken to obtain the percentage of the harmonic content corresponding to each inverter, which is used as the waveform distortion degree of each inverter corresponding to the photovoltaic station.

[0038] As an optional implementation, the analysis obtains the suppression performance coefficient of each inverter corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula The suppression performance coefficient ys of the nth inverter corresponding to the photovoltaic station is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, xb′ is the set reference harmonic content, sz′ is the set waveform distortion, xb n is the harmonic content of the nth inverter in the photovoltaic station, sz n is the waveform distortion of the nth inverter in the photovoltaic station, ν1 and ν2 are the weight factors of the set harmonic content and waveform distortion, 0<ν1<1, 0<ν2<1.

[0039] It should also be noted that the weight factors of harmonic content and waveform distortion are obtained through principal component analysis. The information of the corresponding harmonic content and waveform distortion is first condensed, and then the corresponding variance explanation rate is obtained, and then divided by the variance explanation rate to obtain the corresponding weight.

[0040] The equipment energy efficiency evaluation module is used to analyze and obtain the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station according to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, and determine the energy efficiency status of each inverter corresponding to the photovoltaic station;

[0041] As an optional implementation, the analysis obtains the energy efficiency evaluation coefficient of each inverter device corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula Then the energy efficiency evaluation coefficient LX of the nth inverter equipment corresponding to the photovoltaic station is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, bxn is the performance coefficient of the nth inverter corresponding to the photovoltaic station, kz n is the control capability coefficient of the nth inverter of the photovoltaic station corresponding to the photovoltaic array output power, ys n is the suppression performance coefficient of the nth inverter corresponding to the PV station, q1, q2, q3 are the weight factors of the performance coefficient, the controllability coefficient, and the suppression performance coefficient, respectively, 0<q1<1, 0<q2<1, 0<q3<1, and e is a natural constant.

[0042] It should be noted that the weight factors of the performance coefficient, the control ability coefficient and the inhibition performance coefficient are obtained by principal component analysis. The information of the corresponding performance coefficient, control ability coefficient and inhibition performance coefficient is condensed first, and then the corresponding variance explanation rate is obtained, and then divided by the variance explanation rate to get the corresponding weight.

[0043] As an optional implementation manner, the energy efficiency status of each inverter device corresponding to the photovoltaic station is determined, and the specific judgment process is as follows: the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is compared with the energy efficiency evaluation coefficient threshold stored in the database. If the energy efficiency evaluation coefficient of a certain inverter corresponding to the photovoltaic station is less than the energy efficiency evaluation coefficient threshold stored in the database, then it is determined that the energy efficiency status of the inverter corresponding to the photovoltaic station is abnormal; if the energy efficiency evaluation coefficient of a certain inverter corresponding to the photovoltaic station is greater than or equal to the energy efficiency evaluation coefficient threshold stored in the database, then it is determined that the energy efficiency status of the inverter corresponding to the photovoltaic station is normal, thereby determining the energy efficiency status of each inverter corresponding to the photovoltaic station.

[0044] The early warning terminal is used to issue an early warning prompt when the energy efficiency status of a certain inverter device corresponding to the photovoltaic station is abnormal.

[0045] See also Figure 2 As shown, a method for evaluating energy efficiency of photovoltaic station equipment includes: step one, conversion efficiency monitoring: monitoring each inverter device corresponding to the photovoltaic station, by monitoring the input power and output power of each inverter corresponding to the photovoltaic station, and then analyzing and obtaining the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station, and then analyzing and obtaining the performance coefficient of each inverter corresponding to the photovoltaic station.

[0046] Step 2: Power point tracking analysis: Monitor the maximum power point tracking performance information of each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station.

[0047] Step 3: Harmonic distortion analysis: monitor the current waveform data of each inverter corresponding to the photovoltaic station, and then analyze and obtain the suppression performance coefficient of each inverter corresponding to the photovoltaic station.

[0048] Step 4: Equipment energy efficiency evaluation: According to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is analyzed and the energy efficiency status of each inverter corresponding to the photovoltaic station is determined.

[0049] Step 5: Early warning: When the energy efficiency status of a certain inverter device in the photovoltaic station is abnormal, an early warning will be issued.

[0050] In the embodiment of the present invention, the conversion efficiency between the input power and the output power of each inverter corresponding to the photovoltaic station is analyzed to obtain the performance coefficient thereof, and the maximum power point tracking performance corresponding to each inverter under various sunshine conditions of the photovoltaic station is monitored to obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter of the photovoltaic station by analyzing, and the current waveform data of each inverter corresponding to the photovoltaic station is monitored to obtain the suppression performance coefficient of each inverter corresponding to the photovoltaic station by analyzing. Based on the above analysis, the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is obtained, and the energy efficiency of each inverter corresponding to the photovoltaic station is determined. The energy efficiency status of each inverter in the photovoltaic station can be monitored in real time to realize the real-time monitoring of the operating status of each inverter equipment in the photovoltaic station, understand the performance and energy efficiency of the inverter equipment during operation, timely discover potential problems and risks, and solve the deficiencies in the current technology. Through comprehensive energy efficiency monitoring and analysis of each inverter in the photovoltaic station, the overall equipment operation energy efficiency of the photovoltaic station can be improved, the efficient power generation of the photovoltaic station can be guaranteed, the inverter failure rate and maintenance time can be reduced, the inverter maintenance cost can be reduced, and the power generation efficiency of the photovoltaic station can be improved, so as to maximize the use of solar energy resources and provide a solid foundation for the efficient operation and management of photovoltaic stations.

[0051] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined in this specification, they shall all fall within the protection scope of the present invention.

Claims

1. A photovoltaic station equipment energy efficiency evaluation system, characterized in that: include: The conversion efficiency monitoring module is used to monitor the inverter devices corresponding to the photovoltaic station. By monitoring the input power and output power of each inverter corresponding to the photovoltaic station, the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station is analyzed, and the performance coefficient of each inverter corresponding to the photovoltaic station is analyzed. The power point tracking analysis module is used to monitor the maximum power point tracking performance information of each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station; The harmonic distortion analysis module is used to monitor the current waveform data of each inverter corresponding to the photovoltaic station. The current waveform data includes harmonic content and waveform distortion, and then analyzes and obtains the suppression performance coefficient of each inverter corresponding to the photovoltaic station; The equipment energy efficiency evaluation module is used to analyze and obtain the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station according to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, and determine the energy efficiency status of each inverter corresponding to the photovoltaic station; The early warning terminal is used to issue an early warning prompt when the energy efficiency status of a certain inverter device corresponding to the photovoltaic station is abnormal.

2. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The monitoring photovoltaic station corresponds to the conversion efficiency between the input power and the output power of each inverter. The specific monitoring process is as follows: Before monitoring the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station, set the input voltage, input current, output voltage and output current measurement data, and use the sensors installed at the input and output ends of the inverter to collect the data value information of the input voltage, input current, output voltage and output current of each inverter in real time. According to the input voltage and input current, output voltage and output current collected in real time, they are respectively substituted into the calculation formula to calculate the input power and output power of each inverter corresponding to the photovoltaic station. At the same time, the output power of each inverter corresponding to the photovoltaic station is divided by the input power and multiplied by the percentage to obtain the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station, which is recorded as wb n .

3. A photovoltaic field equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The analysis above obtains the performance coefficient of each inverter corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula Then the performance coefficient bx of the nth inverter corresponding to the photovoltaic station is obtained by analysis: n , n is the number of each inverter, n = 1, 2, ....., m, m is any integer greater than 2, wb n is the conversion efficiency between the input power and output power of the nth inverter corresponding to the photovoltaic station, wb′ is the set reference conversion efficiency, cd n It is the time scale between the input power and output power of the nth inverter in the photovoltaic station.

4. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The monitoring process of the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions of the photovoltaic station is as follows: The demand monitoring data corresponding to each inverter under various sunshine conditions of the photovoltaic station is set, including the maximum power point tracking speed, the maximum power point accuracy and the maximum power point stability rate. The output voltage and current of the photovoltaic array are collected in real time through the sensor installed between the photovoltaic array and the inverter. The collected output voltage and current of the photovoltaic array are substituted into the algorithm to obtain the maximum power point corresponding to each inverter, and then the maximum power point tracking performance information of each inverter after determining the maximum power point is obtained, including the maximum power point tracking speed, the maximum power point accuracy and the maximum power point stability rate. In this way, the maximum power point tracking performance information corresponding to each inverter under various sunshine conditions of the photovoltaic station is monitored.

5. A photovoltaic field equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The analysis obtains the control capability coefficient of each inverter of the photovoltaic station corresponding to the output power of the photovoltaic array. The specific analysis process is as follows: By calculating the formula The control capability coefficient kz of the nth inverter of the photovoltaic station corresponding to the output power of the photovoltaic array is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, u is the number under various sunshine conditions, u=1,2,.....,j, j is any integer greater than 2, cs′ is the set reference maximum power point tracking speed, at′ is the set reference maximum power point accuracy, pq′ is the set reference maximum power point stability rate, cs nj is the maximum power point tracking speed corresponding to the nth inverter under the jth sunshine condition of the photovoltaic station, at nj is the maximum power point accuracy of the nth inverter under the jth sunshine condition of the photovoltaic station, pq nj is the maximum power point stability rate corresponding to the nth inverter under the jth sunshine condition of the PV station, f1, f2, and f3 are the weight factors of the maximum power point tracking speed, the maximum power point accuracy, and the maximum power point stability rate, respectively, 0<f1<1, 0<f2<1, 0<f3<1.

6. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The monitoring photovoltaic station corresponds to the current waveform data of each inverter, and the specific monitoring process is as follows: By real-time monitoring of the current waveform data output by each inverter of the photovoltaic station, and digitizing the monitored current waveform data, the current waveform signal is converted into a digital signal format, and the spectrum analysis algorithm is used to decompose the current waveform signal into components of different frequencies to form a corresponding spectrum diagram, and the amplitude and frequency of each order harmonic of each inverter are obtained from the spectrum diagram. According to the harmonic amplitude data corresponding to each inverter in the spectrum diagram, the harmonic content corresponding to each inverter is calculated, and the square of the harmonic content corresponding to each inverter is summed, and the square root is taken to obtain the percentage of the harmonic content corresponding to each inverter, which is used as the waveform distortion degree of each inverter corresponding to the photovoltaic station.

7. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The analysis obtains the suppression performance coefficient of each inverter corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula The suppression performance coefficient ys of the nth inverter corresponding to the photovoltaic station is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, xb′ is the set reference harmonic content, sz′ is the set waveform distortion, xb n is the harmonic content of the nth inverter in the photovoltaic station, sz n is the waveform distortion of the nth inverter in the photovoltaic station, ν1 and ν2 are the weight factors of the set harmonic content and waveform distortion, 0<ν1<1, 0<ν2<1.

8. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The analysis obtains the energy efficiency evaluation coefficient of each inverter device corresponding to the photovoltaic station. The specific analysis process is as follows: By calculating the formula Then the energy efficiency evaluation coefficient LX of the nth inverter equipment corresponding to the photovoltaic station is obtained by analysis. n , n is the number of each inverter, n=1,2,.....,m, m is any integer greater than 2, bx n is the performance coefficient of the nth inverter corresponding to the photovoltaic station, kz n is the control capability coefficient of the nth inverter of the photovoltaic station corresponding to the photovoltaic array output power, ys n is the suppression performance coefficient of the nth inverter corresponding to the PV station, q1, q2, q3 are the weight factors of the performance coefficient, the controllability coefficient, and the suppression performance coefficient, respectively, 0<q1<1, 0<q2<1, 0<q3<1, and e is a natural constant.

9. A photovoltaic station equipment energy efficiency evaluation system as claimed in claim 1, characterized in that: The energy efficiency status of each inverter device corresponding to the photovoltaic station is obtained by the judgment, and the specific judgment process is as follows: The energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is compared with the energy efficiency evaluation coefficient threshold stored in the database. If the energy efficiency evaluation coefficient of a certain inverter corresponding to the photovoltaic station is less than the energy efficiency evaluation coefficient threshold stored in the database, it is determined that the energy efficiency state of the inverter corresponding to the photovoltaic station is abnormal; if the energy efficiency evaluation coefficient of a certain inverter corresponding to the photovoltaic station is greater than or equal to the energy efficiency evaluation coefficient threshold stored in the database, it is determined that the energy efficiency state of the inverter corresponding to the photovoltaic station is normal, thereby determining the energy efficiency state of each inverter corresponding to the photovoltaic station.

10. A photovoltaic field station equipment energy efficiency evaluation method implementing the photovoltaic field station equipment energy efficiency evaluation system according to any one of claims 1 to 9, characterized in that: include: Step 1: Conversion efficiency monitoring: monitor the inverter equipment corresponding to the photovoltaic station, monitor the input power and output power of each inverter corresponding to the photovoltaic station, and then analyze the conversion efficiency between the input power and output power of each inverter corresponding to the photovoltaic station, and then analyze and obtain the performance coefficient of each inverter corresponding to the photovoltaic station; Step 2: Power point tracking analysis: monitor the maximum power point tracking performance information of each inverter under various sunshine conditions in the photovoltaic station, and then analyze and obtain the control capability coefficient of the photovoltaic array output power corresponding to each inverter in the photovoltaic station; Step 3: Harmonic distortion analysis: monitor the current waveform data of each inverter corresponding to the photovoltaic station, and then analyze and obtain the suppression performance coefficient of each inverter corresponding to the photovoltaic station; Step 4: Equipment energy efficiency evaluation: According to the performance coefficient of each inverter corresponding to the photovoltaic station, the control capability coefficient of the photovoltaic array output power, and the suppression performance coefficient, the energy efficiency evaluation coefficient of each inverter corresponding to the photovoltaic station is analyzed and the energy efficiency status of each inverter corresponding to the photovoltaic station is determined; Step 5: Early warning: When the energy efficiency status of a certain inverter device in the photovoltaic station is abnormal, an early warning will be issued.

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