Method for setting the availability rate of photovoltaic power participation in power balance

Abstract

The invention discloses a method for setting the availability rate of photovoltaic participation in power balance, comprising the following steps: S1, collecting photovoltaic output history data and photovoltaic installed capacity data of a required calculation time; S2, performing data processing on the collected photovoltaic output history data, taking out and sorting holiday data separately, and dividing them into ordinary data and holiday data; S3, performing per-unit processing on the data obtained in S2; S4, classifying them according to months (holidays), and splicing them to obtain a data set with months (holidays) as categories; S5, using the 3-sigma rule to perform correction calculation on the data in the data set that does not meet the requirements; S6, calculating the availability rate of photovoltaic participation in power balance in each month (holiday); the method can effectively calculate the availability of photovoltaics in a medium- and long-term power balance plan, which is beneficial to assisting a scheduling planning organization in arranging a balance plan for conventional power sources and ensuring the safety and stability of the power system.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic participation in power balance availability of power systems, and in particular to a method for setting photovoltaic participation in power balance availability. Background Art

[0002] Under the goals of carbon peak and carbon neutrality, the installed capacity of photovoltaic power generation will increase day by day, and photovoltaic power generation will become the main power generation source in the power system in the future. However, for renewable energy such as photovoltaics, its power generation has certain volatility and randomness. The closer the prediction of its power output is to the actual operation time, the more accurate the prediction result will be. For the formulation of medium- and long-term power balance plans for power systems, the formulation time may be as long as weeks, months, or even years. At this time, it is almost impossible to accurately predict the output of photovoltaic power generation. At this time, unreasonable formulation of the availability of photovoltaic participation in power balance will affect the planning and arrangement of other power generating units, and finally affect the operation of the power system during actual operation.

[0003] Taking into account that photovoltaic power generation has certain characteristics in different months, such as photovoltaic output is higher in summer than in winter, in this regard, we can perform statistical calculations on the photovoltaic output data of each month based on historical photovoltaic output data, and finally obtain the availability of photovoltaics in each month, which can effectively assist in the formulation of medium- and long-term power balance.

[0004] For example, a "method for setting the frequency deviation coefficient of a power grid control area" disclosed in Chinese patent literature, with the publication number: CN20181-6112868, discloses a method for setting the frequency deviation coefficient by adaptively changing the weight according to the actual output of the generator set, but does not take into account the power generation conditions of photovoltaic power generation during many holidays. Summary of the invention

[0005] To this end, the present invention provides a method for setting the availability rate of photovoltaic participation in power balance, which can assist power grid organizations to reasonably consider the availability of photovoltaics in formulating medium- and long-term power balance plans, so as to achieve the purpose of improving the flexible operation of the power system.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The method for setting the availability rate of photovoltaic power balance includes the following steps:

[0008] S1. Collect historical photovoltaic output data and photovoltaic installed capacity data for the required calculation time;

[0009] S2. Process the collected historical photovoltaic output data, extract and sort the holiday data separately, and divide them into ordinary data and holiday data;

[0010] S3, normalize the data obtained in S2;

[0011] S4, classify by month (holiday), and concatenate them to obtain a data set with month (holiday) as the category;

[0012] S5. Use the 3-sigma rule to correct the data in the data set that does not meet the requirements.

[0013] S6. Calculate the photovoltaic power balance availability rate in each month (holidays).

[0014] Preferably, S1 includes: determining the time for calculating the photovoltaic availability, such as the maximum load time; after determining the specific time, collecting the photovoltaic output history data of the corresponding time every day; and collecting the photovoltaic installed capacity of the corresponding date. By determining the specific load time, the photovoltaic power generation data to be calculated can be obtained more accurately.

[0015] Preferably, S2 includes: dividing dates into ordinary dates and holiday dates, where holiday dates include, for example, Spring Festival holidays, National Day holidays, etc., and then classifying the photovoltaic output history data obtained in S1 according to ordinary date historical output data and holiday historical output data.

[0016] Preferably, S3 includes: according to the historical output data of ordinary dates and the historical output data of holidays obtained in S2, and the photovoltaic installed capacity data of the corresponding date in S1, the historical output data and the photovoltaic installed capacity data of the corresponding date are compared and calculated according to the following formula to obtain the output per unit value:

[0017]

[0018] in, is the per unit value of photovoltaic output on the dth day of the mth month of the yth year; P y,m,d is the photovoltaic power output on the dth day of the mth month of the yth year; Q y,m,d The photovoltaic installed capacity on the dth day of the mth month of the yth year. The per unit value of data under different categories can be calculated.

[0019] Preferably, S4 includes: after calculating the photovoltaic output per unit value on ordinary dates (holidays), splicing the data of the same month in different years (the same holiday data in different years) to obtain the output data set of the same month (the same holiday) to analyze its output distribution. Taking the output per unit value on ordinary dates as an example, the specific calculation is shown in the following formula:

[0020] x m =[P y1,m,d1 ,P y1 ,m,d2,...,P yk,m,dn ]

[0021] Among them, x m is the output per unit value data set for the mth month, P y1,m,d1 The per unit output data corresponding to the day d1 of the mth month of the yth year can be counted together.

[0022] Preferably, S5 includes: using the 3-sigma rule to perform correction calculation on the data in the data set sorted in step 4. 3-sigma is the distribution within 3 standard deviations of the normal distribution, indicating that the probability of data distribution within the range of three standard deviations is almost 99.7%, which has a high credibility. The corresponding calculation formula is as follows:

[0023]

[0024] Among them, x m The mth month output per unit value data set; x y,m,d is the element of the data set, which is the photovoltaic output per unit value on the dth day of the mth month of the yth year; avg(x m ),std(x m ) are the mean and standard deviation of the per unit output value in month m, It is the corrected per unit value of the photovoltaic output on the dth day of the mth month of the yth year after the conditions are met.

[0025] The meanings of the above formulas are as follows: First, corresponding to the first item, if the original data x y,m,d Greater than a certain value (this patent is avg(x m )+2·std(x m )), then the original data is corrected to avg(x m )+2·std(x m ); if the original data x y,m,d Less than a certain value (this patent is avg(x m )-2·std(x m )), then the original data is corrected to avg(x m )-2·std(x m ); otherwise, the original data is retained without modification.

[0026] Preferably, S6 includes: performing arithmetic mean processing on the corrected data set calculated in step 5 to calculate the availability of photovoltaic power generation in each month. The specific calculation formula is as follows:

[0027]

[0028] in, is the output per unit value data set of the mth month obtained after correction in step 5; rm is the photovoltaic power generation availability rate in the mth month; avg(·) is the arithmetic mean operation. The photovoltaic power generation availability rate of the average value under the per-unit value can be obtained.

[0029] The embodiments of the present invention have the following advantages:

[0030] (1) The present invention adopts a relatively intuitive statistical calculation method and can obtain stable analysis results; (2) The present invention reasonably considers the availability of photovoltaic power generation in the medium- and long-term power balance plan, effectively assists in the formulation of the medium- and long-term power balance, and is conducive to the flexible operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0032] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0033] Figure 1 It is a flow chart of the steps of the present invention.

[0034] Figure 2 It is the photovoltaic availability rate at the time of maximum load scheduling in the embodiment of the present invention.

[0035] Figure 3 It is the photovoltaic availability rate at the time of maximum load in the embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. 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.

[0037] like Figure 1-3As shown, in a preferred embodiment, the present invention discloses a wrench that can be used as a temporary latch, comprising:

[0038] S1. Collect the historical data of photovoltaic output at the time required for calculation, and collect the photovoltaic installed capacity data at the same time; first determine the time to calculate the photovoltaic availability, such as the maximum load time; after determining the specific time, collect the historical data of photovoltaic output at the corresponding time every day; and collect the photovoltaic installed capacity of the corresponding date at the same time.

[0039] S2. Process the collected historical photovoltaic output data, extract and organize the holiday data separately, and divide them into ordinary data and holiday data; first, divide the dates into ordinary dates and holiday dates, and the holiday dates include, for example, the Spring Festival holiday, the National Day holiday, etc., and then classify the historical photovoltaic output data obtained in step 1 according to the historical output data of ordinary dates and the historical output data of holidays.

[0040] S3: Perform per-unit processing on the data obtained in S2; based on the historical output data of ordinary dates and historical output data of holidays obtained in S2, and the photovoltaic installed capacity data of the corresponding date in step 1, the historical output data and the photovoltaic installed capacity data of the corresponding date are compared and calculated according to the following formula to obtain the output per-unit value:

[0041]

[0042] in, is the per unit value of photovoltaic output on the dth day of the mth month of the yth year; P y,m,d is the photovoltaic power output on the dth day of the mth month of the yth year; Q y,m,d The PV installed capacity on the dth day of the mth month of the yth year.

[0043] S4. Classify the normalized data according to month (holiday) and splice them to obtain a data set classified by month (holiday); after calculating the per-unit value of photovoltaic output on ordinary dates (holidays), splice the data of the same month in different years (the same holiday data in different years) to obtain the output data set of the same month (same holiday) to analyze its output distribution. Taking the per-unit value of output on ordinary dates as an example, the specific calculation is shown in the following formula:

[0044] x m =[P y1,m,d1 ,P y1,m,d2 ,...,P yk,m,dn ];

[0045] Among them, x m is the output per unit value data set for the mth month, P y1,m,d1 It is the output per unit value data corresponding to the d1th day of the mth month of the y1th year.

[0046] S5. Use the 3-sigma rule to correct the data in the data set that does not meet the requirements; 3-sigma is the distribution within 3 standard deviations of the normal distribution, which means that the probability of data distribution within the range of three standard deviations is almost 99.7%, which has a high degree of credibility. The corresponding calculation formula is as follows:

[0047]

[0048] Among them, x m The mth month output per unit value data set; x y,m,d is the element of the data set, which is the photovoltaic output per unit value on the dth day of the mth month of the yth year; avg(x m ),std(x m ) are the mean and standard deviation of the per unit output value in month m, It is the corrected per unit value of the photovoltaic output on the dth day of the mth month of the yth year after the conditions are met.

[0049] The meanings of the above formulas are as follows: First, corresponding to the first item, if the original data x y,m,d Greater than a certain value (this patent is avg(x m )+2·std(x m )), then the original data is corrected to avg(x m )+2·std(x m ); if the original data x y,m,d Less than a certain value (this patent is avg(x m )-2·std(x m )), then the original data is corrected to avg(x m )-2·std(x m ); otherwise, keep the original data without modification

[0050] S6. Calculate the availability of photovoltaic power balance in each month (holiday) using the revised data set. Take the arithmetic mean of the revised data set calculated in step 5 to calculate the availability of photovoltaic power generation in each month. The specific calculation formula is as follows:

[0051]

[0052] in, is the output per unit value data set of the mth month obtained after correction in step 5; r m is the photovoltaic power generation availability rate in the mth month; avg(·) is the arithmetic mean operation.

[0053] In another embodiment, the present invention calculates the photovoltaic availability at two times: the maximum load moment of the dispatch and the maximum load moment of the unified dispatch. The photovoltaic output data is the photovoltaic power generation output data of each day from January 2019 to December 2020. In addition, the installed capacity of each month in 2019 and 2020 is shown in Tables 1 and 2.

[0054] Table 1

[0055]

[0056] Table 2

[0057]

[0058] After calculating it using the method proposed in this patent, the photovoltaic availability rate at the maximum load of each month and the photovoltaic availability rate at the maximum load of the unified dispatch are obtained as follows: Figure 2 and Figure 3 shown.

[0059] like Figure 2 and Figure 3 As shown, the maximum photovoltaic availability rate occurred in August, both at the time of maximum dispatching load and at the time of maximum unified dispatching load, with the photovoltaic availability rate reaching 46.1% at the time of maximum dispatching load.

[0060] like Figure 2 As shown in Figure 2, the minimum PV availability at the time of maximum dispatch load occurs in February, which is only 12.2%; the PV availability in summer is usually higher than that in other seasons.

[0061] like Figure 3 As shown in the figure, the minimum PV availability at the time of maximum load occurs in November, which is only 7.1%. In addition, the PV availability in summer is usually higher than that in other seasons. In general, the PV availability at the time of maximum load is lower than 30%.

[0062] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for setting the availability rate of photovoltaic power balance, characterized in that: The steps include: S1. Collect historical photovoltaic output data and photovoltaic installed capacity data for the required calculation time; S2. Divide the dates into ordinary dates and holiday dates, and classify the photovoltaic output historical data according to the ordinary date historical output data and the holiday historical output data; S3, according to the historical output data of ordinary dates and holidays, as well as the photovoltaic installed capacity data of the corresponding dates, the output per unit value is obtained by comparison and calculation; S4. Combine the data of the same month in different years (the data of the same holiday in different years) to obtain the output data set of the same month (the same holiday); S5. Use the 3-sigma rule to correct the data in the data set that does not meet the requirements. The corresponding formula is as follows: Among them, x m The mth month output per unit value data set; x y,m,d is the element of the data set, which is the photovoltaic output per unit value on the dth day of the mth month of the yth year; avg(x m ),std(x m ) are the mean and standard deviation of the per unit output value in month m, The corrected per unit value of the photovoltaic output on the dth day of the mth month of the yth year after the conditions are met; S6. Calculate the photovoltaic power balance availability rate in each month (holidays).

2. The method for setting the availability rate of photovoltaic power balance according to claim 1, characterized in that: The S1 includes: determining the time for calculating the photovoltaic availability; after determining the specific time, collecting the photovoltaic output history data of the corresponding time every day; and collecting the photovoltaic installed capacity of the corresponding date.

3. The method for setting the availability rate of photovoltaic power balance according to claim 1 or 2, characterized in that: The S2 includes: The historical data of photovoltaic output is classified into historical output data on ordinary dates and historical output data on holidays, and the holiday dates include statutory holidays.

4. The method for setting the availability rate of photovoltaic power balance according to claim 1 or 2, characterized in that: The S3 includes: Compare and calculate the historical output data and the photovoltaic installed capacity data of the corresponding date according to the following formula to obtain the output per unit value: in, is the per unit value of photovoltaic output on the dth day of the mth month of the yth year; P y,m,d is the photovoltaic power output on the dth day of the mth month of the yth year; Q y,m,d The PV installed capacity on the dth day of the mth month of the yth year.

5. The method for setting the availability rate of photovoltaic power balance according to claim 1, characterized in that: The S4 includes: splicing the data of the same month in different years (the data of the same holiday in different years) to obtain the output data set of the same month (the same holiday) to analyze the output distribution. Taking the output per unit value of an ordinary date as an example, the specific calculation is shown in the following formula: x m =[P y1,m,d1 ,P y1 ,m,d2,...,P yk,m,dn ] Among them, x m is the output per unit value data set for the mth month, P y1,m,d1 It is the output per unit value data corresponding to the d1th day of the mth month of the y1th year.

6. The method for setting the availability rate of photovoltaic power balance according to claim 1, characterized in that: In S5, if the original data x y,m,d Greater than a certain value (this method is avg(x m )+2·std(x m )), then the original data is corrected to avg(x m )+2·std(x m ); if the original data x y,m,d Less than a certain value (this method is avg(x m )-2·std(x m )), then the original data is corrected to avg(x m )-2·std(x m ); otherwise, the original data is retained without modification.

7. The method for setting the availability rate of photovoltaic power balance according to claim 1, characterized in that: S6 includes: calculating the availability of photovoltaic power generation in each month, and the specific calculation formula is as follows: in, is the output per unit value data set of the mth month obtained after correction in step 5; r m is the photovoltaic power generation availability rate in the mth month; avg(·) is the arithmetic mean operation.

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