A method and system for determining the slope irradiance of a photovoltaic panel

Abstract

The application relates to a method and system for determining the slope irradiance of a photovoltaic panel, comprising: determining the slope molecular scattering irradiance of the photovoltaic panel according to the horizontal plane scattering irradiance of the photovoltaic panel under the clearance condition; determining the slope direct irradiance and the slope meter scattering irradiance of the photovoltaic panel respectively according to the horizontal plane total irradiance of the photovoltaic panel; and determining the slope irradiance of the photovoltaic panel according to the slope direct irradiance, the slope molecular scattering irradiance and the slope meter scattering irradiance of the photovoltaic panel. The technical scheme provided by the application is simple in calculation, high in precision and wide in application range.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and in particular to a method and system for determining the inclined surface irradiance of a photovoltaic panel. Background Art

[0002] The most important factor influencing photovoltaic output is solar irradiance. Generally, the greater the irradiance received by a photovoltaic panel, the greater the photovoltaic output. Because the amount of irradiance received by a photovoltaic panel depends on the solar incidence angle, the irradiance on horizontal and inclined surfaces is not equal, and the difference is often significant.

[0003] To maximize solar radiation energy, photovoltaic panels are typically installed at an angle, with the panel surface facing the equator. However, the irradiance data commonly used in engineering projects is the total irradiance on a horizontal plane. Therefore, it is necessary to convert the total irradiance on a horizontal plane to the irradiance on an inclined plane, a task known as irradiance slope conversion.

[0004] In the irradiance slope conversion, for diffuse radiation, the traditional method usually sets the solar radiation to be isotropic, and on this basis converts the horizontal plane irradiance of the photovoltaic panel into the slope irradiance.

[0005] However, researchers found that scattered radiation mainly includes molecular scattering and Mie scattering. Molecular scattering is typically isotropic, and Mie scattering is mainly forward scattering, that is, the scattering angle is less than 90°. Therefore, the traditional method does not accurately set the solar radiation, resulting in large errors in the calculation results. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for determining the slope irradiance of a photovoltaic panel, which has simple calculation, high accuracy and wide applicability.

[0007] The purpose of the present invention is achieved by adopting the following technical solutions:

[0008] The present invention provides a method for determining the irradiance of a photovoltaic panel on an inclined surface, wherein the method comprises:

[0009] The molecular scattered irradiance of the photovoltaic panel's oblique surface is determined based on the scattered irradiance of the photovoltaic panel's horizontal surface under clear conditions;

[0010] According to the total irradiance of the photovoltaic panel on the horizontal surface, the direct irradiance and the Mie scattered irradiance of the photovoltaic panel on the inclined surface are determined respectively;

[0011] The slope irradiance of the photovoltaic panel is determined based on the slope direct irradiance, slope molecular scattered irradiance and slope Mie scattered irradiance of the photovoltaic panel.

[0012] Preferably, the determining of the molecular scattered irradiance of the oblique surface of the photovoltaic panel according to the scattered irradiance of the horizontal surface of the photovoltaic panel under the clearance condition comprises:

[0013] Determine the slope molecular scattering irradiance S' of the photovoltaic panel at time t by the following formula: r,d (t):

[0014]

[0015] Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel;

[0016] The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t):

[0017] S r,d (t) = S d,c (t)

[0018] Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

[0019] Furthermore, before determining the molecular scattered irradiance of the photovoltaic panel's oblique surface according to the horizontal scattered irradiance of the photovoltaic panel under the clearance condition, the method further includes:

[0020] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t):

[0021] S d,c (t) = S o (t)·τ d (t)·cosθ(t)

[0022] Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t;

[0023] Among them, S o (t) is determined as follows:

[0024]

[0025] Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t;

[0026] τ d (t) is determined as follows:

[0027] τ d (t)=0.271-0.294·τ b(t)

[0028] Where, τ b (t) is the direct transparency coefficient at time t;

[0029] τ b (t) is determined as follows:

[0030]

[0031] Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t;

[0032] M h (t) is determined as follows:

[0033]

[0034] Where h is the altitude of the photovoltaic panel;

[0035] θ(t) is determined by the following formula:

[0036]

[0037] Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0038] Preferably, determining the oblique direct irradiance and oblique Mie diffuse irradiance of the photovoltaic panel according to the horizontal total irradiance of the photovoltaic panel includes:

[0039] Determine the scattering ratio of the location of the photovoltaic panel based on the total horizontal irradiance of the photovoltaic panel;

[0040] Determine the horizontal scattered irradiance and horizontal direct irradiance of the photovoltaic panel based on the scattering ratio of the location of the photovoltaic panel;

[0041] Determine the inclined plane scattered irradiance of the photovoltaic panel based on the horizontal plane scattered irradiance of the photovoltaic panel;

[0042] The direct irradiance of the inclined surface of the photovoltaic panel is determined according to the direct irradiance of the horizontal surface of the photovoltaic panel.

[0043] Furthermore, determining the scattering ratio of the location of the photovoltaic panel based on the total horizontal irradiance of the photovoltaic panel includes:

[0044] Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula:

[0045]

[0046] Where k Tis the clearance index of the location of the photovoltaic panel at time t.

[0047] The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T :

[0048]

[0049] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and θ(t) is the solar zenith angle at time t.

[0050] Furthermore, the determining of the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel according to the scattering ratio of the location of the photovoltaic panel includes:

[0051] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t):

[0052] S d (t) = S(t)·DF

[0053] Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t):

[0054] S b (t) = S(t) - S d (t)

[0055] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

[0056] Furthermore, the step of determining the inclined Mie scattered irradiance of the photovoltaic panel based on the horizontal scattered irradiance of the photovoltaic panel includes:

[0057] According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0058] S m,d (t) = S d (t)-S r,d (t);

[0059] According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0060]

[0061] Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d(t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S′ m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel, θ′(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

[0062] Furthermore, the oblique solar incident angle θ′(t) of the photovoltaic panel at time t is determined by the following formula:

[0063] θ′(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)]

[0064] Determine the solar azimuth angle α(t) at time t using the following formula:

[0065]

[0066] Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), and α(t) is the solar azimuth at time t. is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0067] Furthermore, determining the direct irradiance of the inclined surface of the photovoltaic panel based on the direct irradiance of the horizontal surface of the photovoltaic panel includes:

[0068] Determine the direct irradiance S′ of the photovoltaic panel on the inclined surface at time t by the following formula: b (t):

[0069]

[0070] Where θ′(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, and S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

[0071] Preferably, the determining of the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, oblique surface molecular scattered irradiance and oblique surface Mie scattered irradiance of the photovoltaic panel comprises:

[0072] Determine the slope irradiance S′(t) of the photovoltaic panel at time t using the following formula:

[0073] S′(t)=S′ b (t)+S′ m,d (t)+S′ r,d (t)

[0074] Where S′ b (t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S′ m,d (t) is the inclined Mie scattered irradiance of the photovoltaic panel at time t, S′ r,d (t) is the oblique molecular scattering irradiance of the photovoltaic panel at time t.

[0075] The present invention provides a system for determining the irradiance of a photovoltaic panel on an inclined surface, wherein the system comprises:

[0076] The first determination module is used to determine the molecular scattered irradiance of the photovoltaic panel's inclined surface according to the horizontal scattered irradiance of the photovoltaic panel under a clear condition;

[0077] The second determining module is used to determine the oblique direct irradiance and the oblique Mie scattered irradiance of the photovoltaic panel according to the horizontal total irradiance of the photovoltaic panel;

[0078] The third determining module is used to determine the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, the oblique surface molecular scattered irradiance and the oblique surface Mie scattered irradiance of the photovoltaic panel.

[0079] Preferably, the first determining module includes:

[0080] Determine the slope molecular scattering irradiance S' of the photovoltaic panel at time t by the following formula: r,d (t):

[0081]

[0082] Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel;

[0083] The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t):

[0084] S r,d (t) = S d,c (t)

[0085] Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

[0086] Furthermore, before the first determining module, the method further includes:

[0087] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t):

[0088] S d,c (t) = S o (t)·τ d(t)·cosθ(t)

[0089] Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t;

[0090] Among them, S o (t) is determined as follows:

[0091]

[0092] Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t;

[0093] τ d (t) is determined as follows:

[0094] τ d (t)=0.271-0.294·τ b (t)

[0095] Where, τ b (t) is the direct transparency coefficient at time t;

[0096] τ b (t) is determined as follows:

[0097]

[0098] Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t;

[0099] M h (t) is determined as follows:

[0100]

[0101] Where h is the altitude of the photovoltaic panel;

[0102] θ(t) is determined by the following formula:

[0103]

[0104] Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0105] Preferably, according to the second determination module, it includes:

[0106] A first determining unit is configured to determine a scattering ratio at a location of the photovoltaic panel based on a total horizontal irradiance of the photovoltaic panel;

[0107] The second determining unit is used to determine the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel according to the scattering ratio of the location of the photovoltaic panel;

[0108] A third determining unit is used to determine the inclined Mie scattered irradiance of the photovoltaic panel according to the horizontal scattered irradiance of the photovoltaic panel;

[0109] The fourth determining unit is configured to determine the oblique direct irradiance of the photovoltaic panel according to the horizontal direct irradiance of the photovoltaic panel.

[0110] Furthermore, the first determining unit is configured to:

[0111] Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula:

[0112]

[0113] Where k T is the clearance index of the location of the photovoltaic panel at time t.

[0114] The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T :

[0115]

[0116] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and θ(t) is the solar zenith angle at time t.

[0117] Furthermore, the second determining unit is configured to:

[0118] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t):

[0119] S d (t) = S(t)·DF

[0120] Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t):

[0121] S b (t) = S(t) - S d (t)

[0122] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

[0123] Furthermore, the third determining unit includes:

[0124] According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0125] S m,d (t) = S d (t)-S r,d (t);

[0126] According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0127]

[0128] Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d (t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S′ m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel, θ′(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

[0129] Furthermore, the oblique solar incident angle θ′(t) of the photovoltaic panel at time t is determined by the following formula:

[0130] θ′(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)]

[0131] Determine the solar azimuth angle α(t) at time t using the following formula:

[0132]

[0133] Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), and α(t) is the solar azimuth at time t. is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0134] Furthermore, the fourth determining unit includes:

[0135] Determine the direct irradiance S′ of the photovoltaic panel on the inclined surface at time t by the following formula: b (t):

[0136]

[0137] Where θ′(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, and S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

[0138] Preferably, the third determining module is used to:

[0139] Determine the slope irradiance S′(t) of the photovoltaic panel at time t using the following formula:

[0140] S′(t)=S′ b (t)+S′ m,d (t)+S′ r,d (t)

[0141] Where S′ b (t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S′ m,d (t) is the inclined Mie scattered irradiance of the photovoltaic panel at time t, S′ r,d (t) is the oblique molecular scattering irradiance of the photovoltaic panel at time t.

[0142] Compared with the closest prior art, the present invention has the following beneficial effects:

[0143] The technical solution provided by the present invention determines the molecular scattered irradiance of the inclined surface of the photovoltaic panel according to the horizontal scattered irradiance of the photovoltaic panel under clearance conditions; determines the direct inclined surface irradiance and the Mie scattered irradiance of the photovoltaic panel according to the total horizontal irradiance of the photovoltaic panel; determines the inclined surface irradiance of the photovoltaic panel according to the direct inclined surface irradiance, the molecular scattered irradiance and the Mie scattered irradiance of the photovoltaic panel; splits the horizontal scattered irradiance of the photovoltaic panel into the molecular scattered irradiance of the horizontal surface of the photovoltaic panel and the molecular scattered irradiance of the horizontal surface of the photovoltaic panel, and converts them into the molecular scattered irradiance of the inclined surface of the photovoltaic panel and the Mie scattered irradiance of the horizontal surface of the photovoltaic panel, respectively, thereby improving the refinement and accuracy of the irradiance calculation of the photovoltaic panel.

[0144] The technical solution provided by the present invention regards Mie scattering as the superposition of direct radiation and isotropic scattering in a certain proportion, and on this basis proposes an algorithm for converting the horizontal Mie scattering of photovoltaic panels into the oblique Mie scattering of photovoltaic panels. The algorithm has the characteristics of simple calculation, high efficiency and strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0145] Figure 1 It is a flow chart of a method for determining the slope irradiance of a photovoltaic panel;

[0146] Figure 2 It is a graph of the horizontal irradiance of the photovoltaic panel, the actual photovoltaic output and the irradiance of the inclined surface;

[0147] Figure 3 It is a schematic diagram of the correlation between the horizontal irradiance of the photovoltaic panel and the actual photovoltaic output of the photovoltaic panel, and the correlation between the inclined irradiance of the photovoltaic panel and the actual photovoltaic output of the photovoltaic panel;

[0148] Figure 4 The present invention is a structural diagram of a system for determining the inclined irradiance of a photovoltaic panel. DETAILED DESCRIPTION

[0149] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0150] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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 making creative efforts shall fall within the scope of protection of the present invention.

[0151] The present invention provides a method for determining the slope irradiance of a photovoltaic panel, such as Figure 1 As shown, the method includes:

[0152] Step 101. Determine the molecular scattered irradiance of the photovoltaic panel's oblique surface based on the horizontal scattered irradiance of the photovoltaic panel under clear conditions;

[0153] Step 102: Determine the oblique direct irradiance and oblique Mie diffuse irradiance of the photovoltaic panel based on the total horizontal irradiance of the photovoltaic panel;

[0154] Step 103: Determine the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, oblique surface molecular scattered irradiance, and oblique surface Mie scattered irradiance of the photovoltaic panel.

[0155] In the best embodiment of the present invention, after solar radiation enters the atmosphere, it encounters gas molecules and suspended solid and liquid particles, and part of the radiation changes direction to form scattered radiation.

[0156] There are two main types of scattering: one is molecular scattering (also known as Rayleigh scattering), which is mainly caused by gas molecules; the other is Mie scattering, which is mainly caused by suspended particles such as dust and cloud droplets.

[0157] Molecular scattering is typically isotropic, meaning that the radiation is emitted uniformly in all directions. Molecular scattering is less affected by weather conditions and its amount is relatively stable, typically equal to the total amount of scattered radiation in the clear air irradiance.

[0158] Specifically, step 101 includes:

[0159] Determine the slope molecular scattering irradiance S' of the photovoltaic panel at time t by the following formula: r,d (t):

[0160]

[0161] Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel;

[0162] The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t):

[0163] S r,d (t) = S d,c (t)

[0164] Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

[0165] Specifically, before step 101, the following steps may be included:

[0166] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t):

[0167] S d,c (t) = S o (t)·τ d (t)·cosθ(t)

[0168] Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t;

[0169] In the best embodiment of the present invention, the irradiance at the upper boundary of the atmosphere mainly depends on the relationship between the sun and the earth, that is, the position of the sun from the perspective of the earth's surface coordinate system, which is generally expressed by the solar zenith angle and azimuth angle.

[0170] Among them, S o (t) is determined as follows:

[0171]

[0172] Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t;

[0173] τ d (t) is determined as follows:

[0174] τ d (t)=0.271-0.294·τ b (t)

[0175] Where, τ b (t) is the direct transparency coefficient at time t;

[0176] τ b (t) is determined as follows:

[0177]

[0178] Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t;

[0179] M h (t) is determined as follows:

[0180]

[0181] Where h is the altitude of the photovoltaic panel;

[0182] θ(t) is determined by the following formula:

[0183]

[0184] Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0185] Furthermore, the step 102 includes:

[0186] Step a. Determine the scattering ratio of the location of the photovoltaic panel based on the total irradiance of the horizontal plane of the photovoltaic panel;

[0187] Step b. Determine the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel based on the scattering ratio of the location of the photovoltaic panel;

[0188] Step c. Determine the scattered irradiance of the inclined surface of the photovoltaic panel according to the scattered irradiance of the horizontal surface of the photovoltaic panel;

[0189] Step d. determining the oblique direct irradiance of the photovoltaic panel according to the horizontal direct irradiance of the photovoltaic panel.

[0190] Furthermore, the step a includes:

[0191] Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula:

[0192]

[0193] Where k Tis the clearance index of the location of the photovoltaic panel at time t.

[0194] The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T :

[0195]

[0196] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance at the upper limit of the atmosphere of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

[0197] Furthermore, the step b includes:

[0198] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t):

[0199] S d (t) = S(t)·DF

[0200] Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t):

[0201] S b (t) = S(t) - S d (t)

[0202] Where S(t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

[0203] Furthermore, the step c includes:

[0204] According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0205] S m,d (t) = S d (t)-S r,d (t);

[0206] According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0207]

[0208] Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d (t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S′m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel, θ′(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

[0209] In the preferred embodiment of the present invention, the pseudo direct radiation ratio r refers to the proportion of Mie scattering that is statistically regarded as direct radiation; and 1-r refers to the proportion of Mie scattering that is statistically regarded as scattered radiation.

[0210] Due to the complex and ever-changing weather conditions, the false direct ratio does not have a fixed value, but rather a statistical mean. Users can calculate it based on local actual data, or use an empirical coefficient of 0.7.

[0211] Furthermore, the solar incident angle θ′(t) of the photovoltaic panel at time t is determined by the following formula:

[0212] θ′(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)]

[0213] Determine the solar azimuth angle α(t) at time t using the following formula:

[0214]

[0215] Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), and α(t) is the solar azimuth at time t. is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0216] Furthermore, the step d includes:

[0217] Determine the direct irradiance S′ of the photovoltaic panel on the inclined surface at time t by the following formula: b (t):

[0218]

[0219] Where θ′(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, and S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

[0220] Furthermore, the step 103 includes:

[0221] Determine the slope irradiance S′(t) of the photovoltaic panel at time t using the following formula:

[0222] S′(t)=S′ b (t)+S′ m,d(t)+S′ r,d (t)

[0223] Where S′ b (t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S′ m,d (t) is the inclined Mie scattered irradiance of the photovoltaic panel at time t, S′ r,d (t) is the oblique molecular scattering irradiance of the photovoltaic panel at time t.

[0224] In the best embodiment of the present invention, the technical solution provided by the present invention can be applied to the calculation of photovoltaic power station site selection design, output evaluation, theoretical power, abandoned photovoltaic power, etc.; it can also be applied to the calculation of photovoltaic power station power prediction, power prediction, etc., and has important application value.

[0225] The technical method provided by the present invention can more accurately obtain the solar irradiance of photovoltaic panels, and then more accurately calculate the photovoltaic theoretical power or predict the photovoltaic power. For example, Figure 2 (a) shows the horizontal irradiance of the photovoltaic panel at the historical moment. Figure 2 (b) shows the output of photovoltaic panels at the historical moment. Figure 2 (c) gives the irradiance of the photovoltaic panel slope at the historical moment; Figure 2 (a) and Figure 2 From (b), we can see that the irradiance of the photovoltaic panel on the horizontal surface is very different from the irradiance of the photovoltaic panel on the inclined surface. Figure 3 (a) shows the correlation between the horizontal irradiance of the photovoltaic panel and the corresponding output of the photovoltaic panel. Figure 3 (b) shows the correlation between the irradiance of the photovoltaic panel slope and the output of the photovoltaic panel, which is given by Figure 3 (b) and Figure 3 From (a), it can be seen that the correlation between the irradiance on the inclined surface of the photovoltaic panel and the corresponding output of the photovoltaic panel is stronger than the correlation between the irradiance on the horizontal surface of the photovoltaic panel and the corresponding output of the photovoltaic panel.

[0226] The present invention provides a system for determining the slope irradiance of a photovoltaic panel, such as Figure 4 As shown, the system includes:

[0227] The first determination module is used to determine the molecular scattered irradiance of the photovoltaic panel's inclined surface according to the horizontal scattered irradiance of the photovoltaic panel under a clear condition;

[0228] The second determining module is used to determine the oblique direct irradiance and the oblique Mie scattered irradiance of the photovoltaic panel according to the horizontal total irradiance of the photovoltaic panel;

[0229] The third determining module is used to determine the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, the oblique surface molecular scattered irradiance and the oblique surface Mie scattered irradiance of the photovoltaic panel.

[0230] Specifically, the first determining module includes:

[0231] Determine the slope molecular scattering irradiance S' of the photovoltaic panel at time t by the following formula: r,d (t):

[0232]

[0233] Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel;

[0234] The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t):

[0235] S r,d (t) = S d,c (t)

[0236] Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

[0237] Specifically, before the first determining module, the method further includes:

[0238] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t):

[0239] S d,c (t) = S o (t)·τ d (t)·cosθ(t)

[0240] Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t;

[0241] Among them, S o (t) is determined as follows:

[0242]

[0243] Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t;

[0244] τ d (t) is determined as follows:

[0245] τ d (t)=0.271-0.294·τ b(t)

[0246] Where, τ b (t) is the direct transparency coefficient at time t;

[0247] τ b (t) is determined as follows:

[0248]

[0249] Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t;

[0250] M h (t) is determined as follows:

[0251]

[0252] Where h is the altitude of the photovoltaic panel;

[0253] θ(t) is determined by the following formula:

[0254]

[0255] Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0256] Further, according to the second determination module, including:

[0257] A first determining unit is configured to determine a scattering ratio at a location of the photovoltaic panel based on a total horizontal irradiance of the photovoltaic panel;

[0258] The second determining unit is used to determine the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel according to the scattering ratio of the location of the photovoltaic panel;

[0259] A third determining unit is used to determine the inclined Mie scattered irradiance of the photovoltaic panel according to the horizontal scattered irradiance of the photovoltaic panel;

[0260] The fourth determining unit is configured to determine the oblique direct irradiance of the photovoltaic panel according to the horizontal direct irradiance of the photovoltaic panel.

[0261] Furthermore, the first determining unit is configured to:

[0262] Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula:

[0263]

[0264] Where k T is the clearance index of the location of the photovoltaic panel at time t.

[0265] The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T :

[0266]

[0267] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and θ(t) is the solar zenith angle at time t.

[0268] Furthermore, the second determining unit is configured to:

[0269] Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t):

[0270] S d (t) = S(t)·DF

[0271] Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t):

[0272] S b (t) = S(t) - S d (t)

[0273] Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

[0274] Furthermore, the third determining unit includes:

[0275] According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0276] S m,d (t) = S d (t)-S r,d (t);

[0277] According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula:

[0278]

[0279] Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d (t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S′ m,d(t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel, θ′(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

[0280] Furthermore, the solar incident angle θ′(t) of the photovoltaic panel at time t is determined by the following formula:

[0281] θ′(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)]

[0282] Determine the solar azimuth angle α(t) at time t using the following formula:

[0283]

[0284] Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), and α(t) is the solar azimuth at time t. is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

[0285] Furthermore, the fourth determining unit includes:

[0286] Determine the direct irradiance S′ of the photovoltaic panel on the inclined surface at time t by the following formula: b (t):

[0287]

[0288] Where θ′(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, and S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

[0289] Specifically, the third determining module is used to:

[0290] Determine the slope irradiance S′(t) of the photovoltaic panel at time t using the following formula:

[0291] S′(t)=S′ b (t)+S′ m,d (t)+S′ r,d (t)

[0292] Where S′ b (t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S′ m,d (t) is the inclined Mie scattered irradiance of the photovoltaic panel at time t, S′ r,d (t) is the oblique molecular scattering irradiance of the photovoltaic panel at time t.

[0293] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0294] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0295] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0296] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0297] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for determining the slope irradiance of a photovoltaic panel, characterized in that: The method comprises: The molecular scattered irradiance of the photovoltaic panel's oblique surface is determined based on the scattered irradiance of the photovoltaic panel's horizontal surface under clear conditions; According to the total irradiance of the photovoltaic panel on the horizontal surface, the direct irradiance and the Mie scattered irradiance of the photovoltaic panel on the inclined surface are determined respectively; The slant irradiance of the photovoltaic panel is determined according to the slant direct irradiance, slant molecular scattered irradiance and slant Mie scattered irradiance of the photovoltaic panel; The slant direct irradiance and slant Mie diffuse irradiance of the photovoltaic panel are determined based on the total horizontal irradiance of the photovoltaic panel, including: Determine the scattering ratio of the location of the photovoltaic panel based on the total horizontal irradiance of the photovoltaic panel; Determine the horizontal scattered irradiance and horizontal direct irradiance of the photovoltaic panel based on the scattering ratio of the location of the photovoltaic panel; Determine the inclined plane scattered irradiance of the photovoltaic panel based on the horizontal plane scattered irradiance of the photovoltaic panel; Determine the direct irradiance of the inclined surface of the photovoltaic panel based on the direct irradiance of the horizontal surface of the photovoltaic panel; The method of determining the inclined surface Mie scattered irradiance of the photovoltaic panel according to the horizontal surface scattered irradiance of the photovoltaic panel comprises: According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula: S m,d (t)=S d (t)-S r,d (t); According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula: Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d (t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S' m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel location, θ'(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

2. The method according to claim 1, wherein Determining the molecular scattered irradiance of the photovoltaic panel's oblique surface according to the horizontal scattered irradiance of the photovoltaic panel under the clear space condition includes: Determine the slope molecular scattering irradiance S of the photovoltaic panel at time t by the following formula: r ',d(t): Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel; The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t): S r,d (t)=S d,c (t) Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

3. The method according to claim 2, wherein Before determining the molecular scattered irradiance of the photovoltaic panel's oblique surface according to the horizontal scattered irradiance of the photovoltaic panel under the clearance condition, the method further includes: Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t): S d,c (t)=S o (t)·τ d (t)·cosθ(t) Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t; Among them, S o (t) is determined as follows: Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t; τ d (t) is determined as follows: t d (t)=0.271-0.294·t b (t) Where, τ b (t) is the direct transparency coefficient at time t; τ b (t) is determined as follows: Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t; M h (t) is determined as follows: Where h is the altitude of the photovoltaic panel; θ(t) is determined by the following formula: Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

4. The method according to claim 1, wherein Determining the scattering ratio of the location of the photovoltaic panel based on the total horizontal irradiance of the photovoltaic panel includes: Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula: Where k T is the clearance index of the location of the photovoltaic panel at time t; The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T : Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and θ(t) is the solar zenith angle at time t.

5. The method according to claim 1, wherein The method of determining the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel according to the scattering ratio of the location of the photovoltaic panel includes: Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t): S d (t)=S(t)·DF Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t): S b (t)=S(t)-S d (t) Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

6. The method according to claim 1, wherein The θ'(t) is determined by the following formula: θ'(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)] The solar azimuth angle α(t) at time t is determined by the following formula: Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

7. The method according to claim 1, wherein The method of determining the direct irradiance of the inclined surface of the photovoltaic panel according to the direct irradiance of the horizontal surface of the photovoltaic panel comprises: Determine the direct irradiance S of the photovoltaic panel on the inclined surface at time t by the following formula: b '(t): Where θ'(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

8. The method according to claim 1, wherein The method of determining the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, the oblique surface molecular scattered irradiance and the oblique surface Mie scattered irradiance of the photovoltaic panel comprises: Determine the slope irradiance S'(t) of the photovoltaic panel at time t using the following formula: S'(t)=S b '(t)+S' m,d (t)+S r ',d(t) Where S b '(t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S' m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, S r ',d(t) is the molecular scattered irradiance of the photovoltaic panel at the moment t.

9. A photovoltaic panel slope irradiance determination system, characterized in that: The system comprises: The first determination module is used to determine the molecular scattered irradiance of the photovoltaic panel's inclined surface according to the horizontal scattered irradiance of the photovoltaic panel under a clear condition; The second determining module is used to determine the oblique direct irradiance and the oblique Mie scattered irradiance of the photovoltaic panel according to the horizontal total irradiance of the photovoltaic panel; A third determining module is used to determine the oblique surface irradiance of the photovoltaic panel according to the oblique surface direct irradiance, the oblique surface molecular scattered irradiance and the oblique surface Mie scattered irradiance of the photovoltaic panel; According to the second determination module, it includes: A first determining unit is configured to determine a scattering ratio at a location of the photovoltaic panel based on a total horizontal irradiance of the photovoltaic panel; The second determining unit is used to determine the horizontal scattered irradiance and the horizontal direct irradiance of the photovoltaic panel according to the scattering ratio of the location of the photovoltaic panel; A third determining unit is used to determine the inclined Mie scattered irradiance of the photovoltaic panel according to the horizontal scattered irradiance of the photovoltaic panel; A fourth determining unit is configured to determine the oblique direct irradiance of the photovoltaic panel according to the horizontal direct irradiance of the photovoltaic panel; The third determining unit includes: According to the horizontal scattered irradiance of the photovoltaic panel, the horizontal Mie scattered irradiance of the photovoltaic panel is determined by the following formula: S m,d (t)=S d (t)-S r,d (t); According to the horizontal Mie scattered irradiance of the photovoltaic panel, the inclined Mie scattered irradiance of the photovoltaic panel is determined by the following formula: Where S m,d (t) is the horizontal Mie scattered irradiance of the photovoltaic panel at time t, S d (t) is the horizontal scattered irradiance of the photovoltaic panel at time t, S r,d (t) is the horizontal molecular scattered irradiance of the photovoltaic panel at time t, S' m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, r is the pseudo direct ratio of the photovoltaic panel location, θ'(t) is the slant solar incidence angle of the photovoltaic panel at time t, and θ(t) is the solar zenith angle at time t.

10. The system according to claim 9, wherein: The first determining module includes: Determine the slope molecular scattering irradiance S of the photovoltaic panel at time t by the following formula: r ',d(t): Where S r,d (t) is the horizontal molecular scattering irradiance of the photovoltaic panel at time t, and β is the inclination angle of the photovoltaic panel; The horizontal molecular scattering irradiance S of the photovoltaic panel at time t is determined by the following formula: r,d (t): S r,d (t)=S d,c (t) Where S d,c (t) is the horizontal scattered irradiance of the photovoltaic panel at time t under clear conditions.

11. The system according to claim 10, wherein: Before the first determination module, the method further includes: Determine the horizontal scattered irradiance S of the photovoltaic panel at time t under clear conditions according to the following formula: d,c (t): S d,c (t)=S o (t)·τ d (t)·cosθ(t) Where S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and sunlight at time t, τ d (t) is the scattering transparency coefficient at time t, θ(t) is the solar zenith angle at time t; Among them, S o (t) is determined as follows: Where, is the solar constant, d o is the average distance between the sun and the earth, d(t) is the distance between the sun and the earth at time t; τ d (t) is determined as follows: t d (t)=0.271-0.294·t b (t) Where, τ b (t) is the direct transparency coefficient at time t; τ b (t) is determined as follows: Where M h (t) is the relative atmospheric volume at the location of the photovoltaic panel at time t; M h (t) is determined as follows: Where h is the altitude of the photovoltaic panel; θ(t) is determined by the following formula: Where ω(t) is the hour angle of the sun at time t, is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

12. The system according to claim 9, wherein The first determining unit is configured to: Determine the scattering ratio DF at the location of the photovoltaic panel at time t using the following formula: Where k T is the clearance index of the location of the photovoltaic panel at time t; The clearance index k at the location of the photovoltaic panel at time t is determined as follows: T : Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, S o (t) is the solar irradiance on the plane perpendicular to the upper boundary of the atmosphere and the sunlight at time t, and θ(t) is the solar zenith angle at time t.

13. The system according to claim 9, wherein: The second determining unit is configured to: Determine the horizontal scattered irradiance S of the photovoltaic panel at time t by the following formula: d (t): S d (t)=S(t)·DF Determine the horizontal direct irradiance S of the photovoltaic panel at time t by the following formula: b (t): S b (t)=S(t)-S d (t) Where S(t) is the total horizontal irradiance of the photovoltaic panel at time t, and DF is the scattering ratio of the location of the photovoltaic panel at time t.

14. The system according to claim 9, wherein: Determine the oblique solar incident angle θ'(t) of the photovoltaic panel at time t using the following formula: θ'(t)=arccos[cosθ(t)×cosβ+sinθ(t)×sinβ×cos(α(t)-ε)] Determine the solar azimuth angle α(t) at time t using the following formula: Where β is the inclination angle of the photovoltaic panel, ε is the orientation angle of the photovoltaic panel (when the photovoltaic panel faces due south, the orientation angle is 180 degrees), and α(t) is the solar azimuth at time t. is the latitude of the location of the photovoltaic panel, and δ(t) is the solar declination angle of the location of the photovoltaic panel at time t.

15. The system according to claim 9, wherein: The fourth determining unit includes: Determine the direct irradiance S of the photovoltaic panel on the inclined surface at time t by the following formula: b '(t): Where θ'(t) is the solar incident angle of the photovoltaic panel at time t, θ(t) is the solar zenith angle at time t, S b (t) is the horizontal direct irradiance of the photovoltaic panel at time t.

16. The system of claim 9, wherein: The third determining module is configured to: Determine the slope irradiance S'(t) of the photovoltaic panel at time t using the following formula: S'(t)=S b '(t)+S' m,d (t)+S r ',d(t) Where S b '(t) is the direct irradiance of the photovoltaic panel on the inclined surface at time t, S' m,d (t) is the slant Mie scattered irradiance of the photovoltaic panel at time t, S r ',d(t) is the molecular scattered irradiance of the photovoltaic panel at the moment t.

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