Method for diagnosing string generation achievement rate of large-scale distributed photovoltaic cluster power station

Abstract

The application provides a large-scale distributed photovoltaic cluster power station group string power generation achievement rate diagnosis method, relates to the technical field of photovoltaic cluster power station power generation diagnosis, first selects a standard group string of a photovoltaic power station, then calculates the daily current value of the standard group string and the daily current value of other group strings, and based on the daily current value of the standard group string and the daily current value of other group strings, the power generation standard achievement rate of other group strings and the power generation standard achievement rate of all other group strings of the photovoltaic power station are respectively obtained, finally, a threshold value of the standard achievement rate is set, and the power generation standard achievement rate is compared with the threshold value of the standard achievement rate, the problems of one or more group strings under a fault equipment are effectively found out through the comparison result, group string level problem diagnosis is realized, and safety and reliability are provided, so that the photovoltaic power generation efficiency is maximized.

Description

Technical Field

[0001] This invention relates to the technical field of power generation diagnosis for photovoltaic cluster power plants, and more specifically, to a method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power plant. Background Technology

[0002] The overexploitation and use of non-renewable energy sources have caused indelible damage to the environment. In recent years, people have begun to pay attention to renewable energy sources. As a type of renewable energy source, solar energy, and its corresponding photovoltaic power generation, has become a popular and promising field.

[0003] Photovoltaic power generation has developed rapidly in recent years, with many cities in my country establishing large, medium, and small-scale power generation bases. Each base has dozens or even hundreds of devices, while large-scale bases may have tens of thousands of devices. A photovoltaic string refers to a unit formed by connecting photovoltaic modules in series to create the smallest unit with the required DC output voltage. In large-scale photovoltaic power generation bases, if a device malfunctions, it is crucial to promptly identify the problem, pinpoint its location, determine the cause of the power generation issue, and provide and record solutions as a reference for similar problems.

[0004] In practical applications, the power generation performance of equipment varies significantly. Some equipment generates power well or even exceeds expectations, while others generate power poorly or even completely unsatisfactory, making it difficult to achieve predetermined goals. This phenomenon has a certain impact on future power generation planning. Therefore, addressing whether equipment power generation meets standards is a crucial aspect of current new energy power generation. In existing technologies, the DBSCAN clustering algorithm is used to perform cluster analysis on photovoltaic power plants, calculating the average daily power generation per unit area for all photovoltaic power plants, which can identify those with power generation problems. However, this method only identifies which photovoltaic power plant has a problem. It is still necessary to investigate the cause of the problem, as it could be due to equipment malfunctions or environmental factors. This process is time-consuming and labor-intensive. Moreover, this method is more comparable to photovoltaic power plants under similar environmental conditions. When there are significant differences in the environment across different regions, and the number of power plants in different environments is limited, the sample size may be too small, resulting in a lack of generalizability and thus lower reference value. Other methods involve establishing a three-tiered structure of station control, relay, and equipment layers, combined with intelligent inspection robots and component cleaning robots, to achieve secondary alarm confirmation inspection and fixed-point cleaning, thereby improving the reliability of power supply. However, these methods still cannot specifically pinpoint the problem of poor power generation performance of a particular string under a particular device, leading to unsatisfactory power generation performance of the entire device. When a large number of devices are experiencing poor power generation, the entire power station may experience significant low power generation efficiency. Summary of the Invention

[0005] To address the problem of diagnosing power generation inefficiencies in one or more strings of a device in a large-scale distributed photovoltaic (PV) cluster power station, this invention proposes a method for diagnosing string power generation achievement rate in large-scale distributed PV cluster power stations. This method can not only identify PV power stations with abnormal power generation, but also effectively detect problems in one or more strings of faulty equipment, achieving string-level problem diagnosis. It is safe and reliable, providing a guarantee for maximizing PV power generation efficiency.

[0006] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows:

[0007] A method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station, the method comprising the following steps:

[0008] S1. Select standard strings for the photovoltaic power station;

[0009] S2. Select a date, obtain and filter the data of valid time points within the daily statistical range of the standard string;

[0010] S3. Calculate the daily current value I of the standard string. 标准组串The daily current value I of other strings under the device containing the standard string. 其他组串 ;

[0011] S4. Calculate the sum of the daily current values ​​of all strings (excluding the standard string) in the photovoltaic power station, multiplied by the corresponding string capacity, sum1, and the string capacity of all strings other than the standard string, sum2.

[0012] S5. Based on the sum of sum1 and string capacity sum2, obtain the daily current value I of other strings in the entire photovoltaic power station. 全站 ;

[0013] S6. Based on I 其他组串 and I 标准组串 Calculate the power generation compliance rate R of other string groups. 其他组串 Based on I 全站 and I 标准组串 Find the power generation compliance rate R of all other strings in the photovoltaic power station. 全站其他组串 ;

[0014] S7. Set the compliance rate threshold, and set R 其他组串 and R 全站其他组串 The values ​​are compared with the compliance rate threshold to determine the faults in the string branches.

[0015] This technical solution first selects the standard strings of a photovoltaic power station, then calculates the daily current value of the standard strings and the daily current value of other strings. Based on the daily current values ​​of the standard strings and other strings, it calculates the power generation compliance rate of other strings and the power generation compliance rate of all other strings in the photovoltaic power station. Finally, it sets a compliance rate threshold and compares the power generation compliance rate with the compliance rate threshold. The comparison results effectively identify problems in one or more strings under faulty equipment, realizing string-level problem diagnosis. This is safe and reliable, and provides a guarantee for maximizing photovoltaic power generation efficiency.

[0016] Preferably, the process of selecting standard strings for a photovoltaic power station in step S1 is as follows:

[0017] S11. Obtain the data of the photovoltaic power station at the effective time point under the historical time period T, and calculate the average ranking of the power generation of each string of each device under the photovoltaic power station in the historical time period T.

[0018] S12. Select the strings that are easy to clean, can be observed at any time under the camera, and rank in the top 30% as the standard strings for the photovoltaic power station.

[0019] Preferably, in step S11, the historical duration T is one week, and the effective time points are several time points under daytime illumination conditions on each day of the week. The data includes: string current, string voltage, string capacity, and irradiance at effective time points that are greater than or equal to a certain specified threshold.

[0020] Preferably, the data of the standard string at valid time points within the daily statistical range includes: string current, string voltage, string capacity, and irradiance at valid time points. When filtering data, string current and string voltage data corresponding to irradiance at valid time points that are greater than or equal to a certain specified threshold are filtered out, and string current data at valid time points that are greater than or equal to a certain specified threshold are also filtered out.

[0021] Preferably, the daily current value I of the standard string is calculated. 标准组串 The process is as follows:

[0022] Let t1, t2, ..., tn be the starting and ending times within the statistical range of the day. Determine the effective currents of standard strings within the statistical range of the day that are greater than or equal to a certain threshold, from the starting to the ending time: I bt1 I bt2 ... I btn ;

[0023] The daily current value I of the standard string is 标准组串 The calculation expression is:

[0024]

[0025] Among them, I bti This represents the current of a standard string at the i-th valid time point that is greater than or equal to a certain threshold, where i = 1, 2, ..., n; C 标准组串 This represents the standard string capacity; n represents the number of valid time points from the start time point to the end time point.

[0026] Daily current value I of other strings under a device containing standard strings 其他组串 The calculation expression is:

[0027]

[0028] Among them, I qti The current at valid time points of other strings within the statistical scope of the day, from the start time point to the end time point, that is greater than or equal to a certain threshold.

[0029] Preferably, the formula for calculating the sum of the daily current values ​​of all strings (excluding standard strings) participating in the calculation under the photovoltaic power station, multiplied by the corresponding string capacities, is as follows:

[0030]

[0031] The formulas for calculating the string capacity and sum2 of strings other than standard strings are as follows:

[0032]

[0033] Where m represents the total number of other strings; I 其它组串j C represents the daily current value of other groups in the j-th string. 其它组串j This represents the capacity of the other substrings in the j-th string.

[0034] Preferably, the daily current value I of the other strings of the photovoltaic power station in step S5 is... 全站 The calculation formula is:

[0035] I 全站 =sum1 / sum2.

[0036] Preferably, the power generation compliance rate R of other string groups 其他组串 The expression for finding is:

[0037]

[0038] The power generation compliance rate R of all other strings in the photovoltaic power station 全站其他组串 The expression for finding is:

[0039]

[0040] Preferably, in step S7, when R 其他组串 or / and R 全站其他组串 When the value is 0, the corresponding string is faulty or disconnected;

[0041] When R 其他组串 Less than the pass rate threshold or R 全站其他组串 When the rate is less than the target threshold, the corresponding string is considered to be generating inefficiently, and an inefficient generation alarm will be transmitted to the staff.

[0042] Preferably, the method further includes: calculating the current value within the monthly statistical range and the current value within the annual statistical range based on the current values ​​of the standard string and other strings within the daily statistical range, thereby calculating the power generation compliance rate within the monthly statistical range and the power generation compliance rate within the annual statistical range.

[0043] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0044] This invention proposes a diagnostic method for the string power generation achievement rate of large-scale distributed photovoltaic (PV) cluster power plants. First, a standard string of the PV power plant is selected. Then, the daily current value of the standard string is calculated and compared with the daily current values ​​of other strings. Based on the daily current values ​​of the standard string and other strings, the power generation achievement rate of other strings and the power generation achievement rate of all other strings in the entire PV power plant are calculated respectively. Finally, a threshold for the achievement rate is set, and the power generation achievement rate is compared with the threshold. The comparison results effectively identify problems in one or more strings under faulty equipment, achieving string-level problem diagnosis. This method is safe and reliable, providing a guarantee for maximizing PV power generation efficiency. Attached Figure Description

[0045] Figure 1 A flowchart illustrating the diagnostic method for string power generation achievement rate of large-scale distributed photovoltaic cluster power stations proposed in Embodiment 1 of the present invention;

[0046] Figure 2 This diagram illustrates the comparison of the power generation compliance rate between the string 6 (PV6) proposed in Embodiment 3 of the present invention and the standard string. Detailed Implementation

[0047] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0048] To better illustrate this embodiment, some parts of the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions;

[0049] It is understandable to those skilled in the art that some well-known details may be omitted from the accompanying drawings.

[0050] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0051] The positional relationships depicted in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0052] Example 1

[0053] In this embodiment, as Figure 1 As shown, a method for diagnosing the string power generation achievement rate of large-scale distributed photovoltaic power clusters is proposed. See [link to relevant documentation]. Figure 1 The method includes the following steps:

[0054] S1. Select standard strings for the photovoltaic power station;

[0055] S2. Select a date, obtain and filter the data of valid time points within the daily statistical range of the standard string;

[0056] S3. Calculate the daily current value I of the standard string. 标准组串The daily current value I of other strings under the device containing the standard string. 其他组串 ;

[0057] S4. Calculate the sum of the daily current values ​​of all strings (excluding the standard string) in the photovoltaic power station, multiplied by the corresponding string capacity, sum1, and the string capacity of all strings other than the standard string, sum2.

[0058] S5. Based on the sum of sum1 and string capacity sum2, obtain the daily current value I of other strings in the entire photovoltaic power station. 全站 ;

[0059] S6. Based on I 其他组串 and I 标准组串 Calculate the power generation compliance rate R of other string groups. 其他组串 Based on I 全站 and I 标准组串 Find the power generation compliance rate R of all other strings in the photovoltaic power station. 全站其他组串 ;

[0060] S7. Set the compliance rate threshold, and set R 其他组串 and R 全站其他组串 The values ​​are compared with the compliance rate threshold to determine the faults in the string branches.

[0061] Example 2

[0062] In this embodiment, the process of selecting standard strings for a photovoltaic power station is as follows:

[0063] S11. Obtain the data of the photovoltaic power station at the effective time point under the historical time period T, and calculate the average ranking of the power generation of each string of each device under the photovoltaic power station in the historical time period T.

[0064] In step S11, the historical duration T is one week, and the effective time points are several time points under daytime illumination conditions for each day of the week. The data includes: string current, string voltage, string capacity, and irradiance at effective time points greater than or equal to a certain specified threshold. Valid data such as string current, string voltage, string capacity, and irradiance at effective time points greater than a certain specified threshold for the seven historical time points are obtained. The average power generation ranking of each device under the power station, including each string under the inverter and combiner box, is calculated over the seven historical time points.

[0065] S12. Select the strings that are easy to clean, can be observed at any time under the camera, and rank in the top 30% as the standard strings for the photovoltaic power station.

[0066] The data for valid time points within the daily statistical range for standard strings include: string current, string voltage, string capacity, and irradiance at the valid time point. When filtering data, string current and string voltage data corresponding to irradiance at valid time points that are greater than or equal to a certain specified threshold are selected, and string current data at valid time points that are greater than or equal to a certain specified threshold are also selected.

[0067] In this embodiment, the daily current value of the standard string is calculated as the evaluation standard for the string, and the daily current value I of the standard string is calculated. 标准组串 The process is as follows:

[0068] Let t1, t2, ..., tn be the starting and ending times within the statistical range of the day. Determine the effective currents of standard strings within the statistical range of the day that are greater than or equal to a certain threshold, from the starting to the ending time: I bt1 I bt2 ... I btn ;

[0069] The daily current value I of the standard string is 标准组串 The calculation expression is:

[0070]

[0071] Among them, I bti This represents the current of a standard string at the i-th valid time point that is greater than or equal to a certain threshold, where i = 1, 2, ..., n; C 标准组串 This represents the standard string capacity; n represents the number of valid time points from the start time point to the end time point.

[0072] Daily current value I of other strings under a device containing standard strings 其他组串 The calculation expression is:

[0073]

[0074] Among them, I qti The current at valid time points of other strings within the statistical scope of the day, from the start time point to the end time point, that is greater than or equal to a certain threshold.

[0075] In this embodiment, the formula for calculating the sum of the daily current values ​​of all strings (excluding standard strings) participating in the calculation under the photovoltaic power station, multiplied by the corresponding string capacities, is as follows:

[0076]

[0077] The formulas for calculating the string capacity and sum2 of strings other than standard strings are as follows:

[0078]

[0079] Where m represents the total number of other strings; I 其它组串j C represents the daily current value of other groups in the j-th string. 其它组串j This represents the capacity of the other substrings in the j-th string.

[0080] The daily current value I of other strings in the entire photovoltaic power station mentioned in step S5 全站 The calculation formula is:

[0081] I 全站 =sum1 / sum2.

[0082] Other string power generation compliance rate R 其他组串 The expression for finding is:

[0083]

[0084] The power generation compliance rate R of all other strings in the photovoltaic power station 全站其他组串 The expression for finding is:

[0085]

[0086] In step S7, when R 其他组串 or / and R 全站其他组串 When the value is 0, the corresponding string is faulty or disconnected;

[0087] When R 其他组串 Less than the pass rate threshold or R 全站其他组串 When the rate is less than the target threshold, the corresponding string is considered to be generating inefficiently, and an inefficient generation alarm will be transmitted to the staff.

[0088] Based on the current values ​​of standard strings and other strings within the daily statistical range, the current values ​​within the monthly and annual statistical ranges are calculated. This allows for the calculation of the power generation compliance rate within the monthly and annual statistical ranges. In practice, by combining the calculated power generation compliance rate with the actual power generation situation, corresponding implementation plans can be formulated to meet actual needs.

[0089] Example 3

[0090] The method proposed in this invention will be described below in conjunction with actual implementation. The voltage and current data of the inverter in the photovoltaic power station targeted in this embodiment are shown in Table 1. This embodiment selects the valid time point data of August 8, 2022.

[0091]

[0092] The data is from August 8, 2022. Valid time points are as follows: data is collected every 5 minutes starting at 11:50 AM until 2:10 PM. Table 1 does not show all the data. There are 8 strings in total, represented as PV1, PV2, PV3, PV4, PV5, PV6, PV7, and PV8. In this embodiment, the standard string is PV2. Each string under this device has a capacity of 4500Wp. The voltage and current data for the corresponding strings can be found in Table 1. Based on the obtained data, the daily current value of the standard string can be calculated.

[0093]

[0094] Note: The sum of currents is 481.9A, 1000 is the unit conversion, 4500 is the standard string capacity, 100 is the total number of valid time points per 5 minutes, and 1.071 is the daily current value of the standard string with three decimal places.

[0095] Then, the daily current values ​​of the other strings were calculated:

[0096] I PV1 =sum(I t1时刻 +I t2时刻 +...+I tn时刻 ) / C 其他组串 / n 有效时刻点

[0097] =459.8*1000 / 4500 / 72=1.419(A)

[0098] I PV3 =sum(I t1时刻 +I t2时刻 +...+I tn时刻 ) / C 其他组串 / n 有效时刻点

[0099] =453.9*1000 / 4500 / 72=1.401(A)

[0100] The current data of string 4 up to the effective time point of 14:10 is 0, and I is calculated as follows: pv4 =0A

[0101] I PV5 =sum(I t1时刻 +I t2时刻 +...+I tn时刻 ) / C 其他组串 / n 有效时刻点

[0102] =449.1*1000 / 4500 / 72=1.386(A)

[0103] I PV6 =sum(I t1时刻 +I t2时刻 +...+I tn时刻 ) / C 其他组串 / n 有效时刻点

[0104] =345.4*1000 / 4500 / 72=1.066(A)

[0105] I PV7 =sum(I t1时刻 +I t2时刻 +...+I tn时刻 ) / C 其他组串 / n 有效时刻点

[0106] =454.3*1000 / 4500 / 72=1.402(A)

[0107] The current data of string 8 up to the effective time point of 14:10 is 0, and I is calculated. pv8 =0(A)

[0108] Calculate the power generation compliance rate of the strings other than the standard strings under this equipment.

[0109] R pv1 =I pv1 / I 标准组串 *100 = 1.419 / 1.367 = 1.04

[0110] R pv3 =I pv3 / I 标准组串 *100 = 1.401 / 1.367 = 1.02

[0111] R pv4 =I pv4 / I 标准组串 *100=0 / 1.367=0

[0112] R pv5 =I pv5 / I 标准组串 *100 = 1.386 / 1.367 = 1.01

[0113] R pv6 =I pv6 / I 标准组串 *100 = 1.066 / 1.367 = 0.78

[0114] R pv7 =Ipv7 / I 标准组串 *100 = 1.402 / 1.367 = 1.03

[0115] R pv8 =I pv8 / I 标准组串 *100=0 / 1.367=0

[0116] As can be seen from the above formula, the daily current value of string 4 and string 8 is 0. This indicates that there is a fault or disconnection problem in these two strings. In this case, an alarm should be issued and a solution should be provided so that staff can handle the problem in a timely manner.

[0117] Meanwhile, the solution to string 6 (PV6) from the above formula shows that its power generation compliance rate R pv6 The threshold for compliance rate is set to 0.8 in this embodiment, which is 0.78. Therefore, relative to the set threshold, string 6 is considered to have low power generation efficiency. At this point, an alarm should be issued for "string 6 low power generation efficiency." Staff need to investigate the cause of this problem. This method not only identifies photovoltaic power plants with abnormal power generation but also effectively detects problems in one or more strings of faulty equipment, achieving string-level problem diagnosis safely and reliably.

[0118] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station, characterized in that, The method includes the following steps: S1. Select standard strings for the photovoltaic power station; S2. Select a date, obtain and filter the data of valid time points within the daily statistical range of the standard string; S3. Calculate the daily current value of the standard string. I 标准组串 Daily current values ​​of other strings under equipment containing standard strings. I 其他组串 ; Calculate the daily current value of the standard string. I 标准组串 The process is as follows: Let t1, t2, ..., tn be the starting and ending times within the statistical range of the day. Determine the effective currents of standard strings within the statistical range of the day that are greater than or equal to a certain threshold, from the starting to the ending time: I bt1 I bt2 ... I btn ; The daily current value of the standard string I 标准组串 The calculation expression is: in, This represents the current of a standard string at the i-th valid time point that is greater than or equal to a certain threshold. i =1,2,…,n;C 标准组串 Indicates the standard string capacity; n represents the number of valid time points from the start time point to the end time point; the daily current value of other strings under the device containing the standard string. I 其他组串 The calculation expression is: in, The current of other strings within the statistical scope of the day, from the start time to the end time, that is greater than or equal to a certain threshold at the valid time points; S4. Calculate the sum of the daily current values ​​of all strings (excluding the standard string) in the photovoltaic power station, multiplied by the corresponding string capacity, sum1, and the string capacity of all strings other than the standard string, sum2. S5. Based on the cumulative sum sum1 and the string capacity sum2, obtain the daily current values ​​of other strings in the entire photovoltaic power station. I 全站 ; S6. Based on I 其他组串 and I 标准组串 Calculate the power generation compliance rate R of other string groups. 其他组串 ,based on I 全站 and I 标准组串 Calculate the power generation compliance rate of all other strings in the photovoltaic power station. R 全站其他组串 ; S7. Set the compliance rate threshold, and set R 其他组串 and R 全站其他组串 The values ​​are compared with the compliance rate threshold to determine the faults in the string branches; Other string power generation compliance rate R 其他组串 The expression for finding is: The power generation compliance rate of all other strings in the photovoltaic power station R 全站其他组串 The expression for finding is: ； When R 其他组串 or / and R 全站其他组串 When the value is 0, the corresponding string is faulty or disconnected; When R 其他组串 Less than the pass rate threshold or R 全站其他组串 When the rate is less than the target threshold, the corresponding string is considered to be generating inefficiently, and an inefficient generation alarm will be transmitted to the staff.

2. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 1, characterized in that, The process of selecting standard strings for a photovoltaic power station in step S1 is as follows: S11. Obtain the data of the photovoltaic power station at the effective time point under the historical time period T, and calculate the average ranking of the power generation of each string of each device under the photovoltaic power station in the historical time period T. S12. Select the strings that are easy to clean, can be observed at any time under the camera, and rank in the top 30% as the standard strings for the photovoltaic power station.

3. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 2, characterized in that, In step S11, the historical duration T is one week, and the effective time points are several time points under daytime illumination conditions on each day of the week. The data includes: string current, string voltage, string capacity, and irradiance at effective time points that are greater than or equal to a certain specified threshold.

4. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 2, characterized in that, The data for valid time points within the daily statistical range for standard strings include: string current, string voltage, string capacity, and irradiance at the valid time point. When filtering data, string current and string voltage data corresponding to irradiance at valid time points that are greater than or equal to a certain specified threshold are selected, and string current data at valid time points that are greater than or equal to a certain specified threshold are also selected.

5. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 1, characterized in that, The formula for calculating the sum of the daily current values ​​of all strings (excluding standard strings) in a photovoltaic power plant, multiplied by their corresponding string capacities (sum1), is as follows: The formulas for calculating the string capacity and sum2 of strings other than standard strings are as follows: Where m represents the total number of other strings; This represents the daily current value of other groups in the j-th string. This represents the capacity of the other substrings in the j-th string.

6. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 5, characterized in that, The daily current values ​​of other strings in the entire photovoltaic power station mentioned in step S5 I 全站 The calculation formula is: 。 7. The method for diagnosing the string power generation achievement rate of a large-scale distributed photovoltaic cluster power station according to claim 1, characterized in that, The method further includes: calculating the current value within the monthly statistical range and the current value within the annual statistical range based on the current values ​​of the standard string and other strings within the daily statistical range, thereby calculating the power generation compliance rate within the monthly statistical range and the power generation compliance rate within the annual statistical range.

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