Photovoltaic power station generating capacity and optical power prediction algorithm

Abstract

The invention discloses a photovoltaic power station generating capacity and optical power prediction algorithm, which comprises the following steps: S1, designing a predicted generating capacity calculation method, and establishing an irradiation dose model according to the orientation and inclination angle of a photovoltaic module; calculating the annual total solar radiation HTX of the slope with the orientation angle; and calculating a comprehensive efficiency coefficient K3. The photovoltaic power station generating capacity and optical power prediction algorithm disclosed by the invention can accurately predict generating capacity, thereby guiding engineering project design, verifying reasonability of a design scheme, and providing a theoretical basis for feasibility research of power station construction from the aspect of operation economy.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic power station power generation prediction, and in particular relates to a photovoltaic power station power generation and light power prediction algorithm. Background Art

[0002] At present, the existing methods for predicting power generation and power generation efficiency all use the total annual solar radiation on the horizontal plane as the main calculation basis, and the K value parameter is used for correction, which makes the method have great shortcomings and the prediction results will inevitably produce large errors. The reasons are:

[0003] First, the horizontal radiation does not take into account factors such as the orientation of the house and the design of the photovoltaic array;

[0004] Second, it is well known that the power generation in summer is very different from that in winter. The total annual radiation calculated based on the monthly average data cannot accurately describe the change pattern of power generation in each month / quarter.

[0005] Third, the value of the correction coefficient is based solely on experience and has a certain degree of arbitrariness. Summary of the invention

[0006] The main purpose of the present invention is to provide a photovoltaic power station power generation and optical power prediction algorithm, which can accurately predict the power generation, thereby guiding the design of engineering projects, verifying the rationality of the design scheme, and providing a theoretical basis for the feasibility study of power station construction from the perspective of operational economy.

[0007] To achieve the above objectives, the present invention provides a photovoltaic power station power generation and optical power prediction algorithm, comprising the following steps:

[0008] Step S1: Design a method for calculating predicted power generation. (When designing a solar photovoltaic power generation system, in order to absorb more solar radiation throughout the year, photovoltaic modules (arrays) are usually laid in a manner that faces the equator and is tilted at a certain angle to the ground plane (roof). Selecting different tilt angles will result in a large difference in the amount of solar radiation received by the array in each month.) By establishing a radiation model for the orientation and tilt angle (slope) of the photovoltaic modules, a formula for calculating predicted power generation is proposed:

[0009]

[0010] Where: E S —Irradiance under standard conditions; E p2 —Annual design forecast power generation (kW·h); P AZ —Component installation capacity (kWp); H TX —Total annual solar radiation on slopes with orientation angles (kW·h / m 2 );K3—comprehensive efficiency coefficient;

[0011] Step S1.1: For the slope with an orientation angle, the total annual solar radiation H TX calculate:

[0012]

[0013] Where: H b is the horizontal direct radiation, H d is the scattered radiation on the horizontal surface, H0 is the solar radiation on the horizontal surface outside the atmosphere, R b is the ratio of direct radiation between the inclined surface and the horizontal surface, and β is the inclination angle;

[0014] Step S1.2: Calculation of comprehensive efficiency coefficient K3:

[0015] K3 includes 10 system parameters: relative transmittance loss, weak light loss, temperature loss, difference between actual component power and nominal power, component mismatch loss, collection cable loss, inverter loss, inverter outlet to grid connection point loss, system availability, and photovoltaic component attenuation rate; the value of K3 is the result of multiplying the 10 system parameters.

[0016] As a further preferred technical solution of the above technical solution, for step S1.1:

[0017] Where: H is the total daily radiation on the horizontal surface; H hour is the average horizontal radiation (data provided by the Meteorological Bureau); T sr and T ss The time of sunrise and sunset;

[0018]

[0019] In the formula: Let K sr =ω1,K ss =ω2; calculate the solar radiation H0 on the horizontal surface outside the atmosphere in one day,

[0020]

[0021] H b =HH d

[0022]

[0023] Description of relevant parameters:

[0024] —Latitude, the north-south angle of the equator, with north latitude being positive; (Geographic Information)

[0025] γ—Component slope azimuth, when the slope faces due south, it is 0, when it faces due east, it is negative, and when it faces due west, it is positive; -180°≤γ≤180°; (geographic information)

[0026] H hour —Hourly average radiation exposure on the horizontal surface (data provided by the Meteorological Bureau);

[0027] β—inclination angle, the angle between the plane and the horizontal plane; (design parameter)

[0028] δ—Declination angle, the angle between the sun’s rays and the equatorial plane at noon, with north being positive; -23.45°≤δ≤23.45°; (calculation)

[0029] α s ——The solar altitude angle, the angle between the horizontal plane and the line connecting the earth and the sun; (calculation)

[0030] ω—Hour angle, changes 15° every hour, negative in the morning, positive in the afternoon, and 0° at noon; (calculation)

[0031] And basic parameter calculation:

[0032] Solar declination angle δ and solar altitude angle α s calculate:

[0033] δ = 23.45 sin(2π (284 + N) / 365); N is the number of days;

[0034]

[0035] Sunrise and sunset angle K sr , K ss calculate:

[0036] Calculate the sunrise and sunset angle K of the inclined surface when the component azimuth angle γ = 0 s ;

[0037]

[0038] Calculate the sunrise and sunset angle K when the component azimuth is γ sr , K ss :

[0039]

[0040] Calculation of the radiation intensity I outside the atmosphere:

[0041] I = 1367 × (1 + 0.033 × cos (2π × N / 365)); N is the number of days.

[0042] As a further preferred technical solution of the above technical solution, in the comprehensive efficiency coefficient K3:

[0043] For the relative transmittance loss:

[0044] The transmittance of conventional ultra-clear tempered glass is (approximately) 92%, and the transmittance of coated glass with anti-reflection film is as high as 96%. The relative transmittance loss of conventional ultra-clear tempered glass is (approximately) 2% of the total solar radiation, and that of high-transmittance, anti-reflection coated tempered glass is (approximately) 1%;

[0045] Low light loss:

[0046] Weak light loss refers to the loss of power generation caused by the reduction of conversion efficiency of components under weak light conditions. There will be certain differences in performance due to different solar radiation in different regions. The definition is that the irradiance is less than 1000W / m 2 The light intensity is defined as low light;

[0047] Power loss due to temperature change:

[0048] (Because the photovoltaic modules are directly exposed to the sun and the space is closed, the operating temperature of the silicon wafer in the optical module is very different from the ambient temperature provided by the weather station. Experiments have shown that:) Under STC conditions, the open circuit voltage temperature coefficient of the photovoltaic module monomer is (approximately) -0.33% / ℃, and the peak power loss rate is (approximately) -0.41% / ℃. Therefore, the model for estimating the battery operating temperature based on the ambient temperature is given as follows:

[0049] T m =E·e a+bWS +T n ;

[0050] Where: T m —PV module operating temperature (℃); E—environmental irradiance (W / m 2 ), provided by the Meteorological Bureau; a, b—(look up table) empirical values; T n —ambient temperature (℃); WS—wind speed (m / s);

[0051] Power loss at operating temperature of photovoltaic modules: η T =(T m -25)×λ T ;

[0052] Where: T m —Operating temperature (℃); λ T —Maximum power temperature influence coefficient (% / ℃) (can be obtained by looking up the table);

[0053] (Loss between the actual power of the module and the nominal power: The existing photovoltaic module technical specifications will mark the "standard test condition power tolerance" as 0 to +5, which means positive tolerance. The power range of a 270W module is between 270W and 275W to be qualified. According to the manufacturer's random inspection report, the actual power of the module is about 1% to 1.8% higher than the nominal power)

[0054] PV panel mismatch loss:

[0055] It refers to the group of strings under the same array or the same MPPT (maximum power point tracking) control. Due to individual differences, the output voltage is the sum of the series components, and the output current is the minimum value of the group of components, resulting in its total output power being less than the nominal power of the group of strings (according to the manufacturer's random inspection report, the mismatch loss of photovoltaic components is about 0 to -1%).

[0056]

[0057] Aggregation cable loss:

[0058] Refers to the DC cable loss. The DC side cable loss is calculated as follows, which is obtained from the resistivity formula. The DC cable resistance is:

[0059]

[0060] Where: ρ is the conductor resistivity, and its value is related to the ambient temperature of the conductor. ρ0 is the resistivity of the conductor at 0°C. a is the correction factor. T is the ambient temperature, °C. L is the conductor length, and S is the conductor cross-sectional area. The power loss and loss rate of the DC side cable are:

[0061]

[0062]

[0063] Inverter loss:

[0064] It includes two parts: the inverter's own loss, and the loss caused by exceeding the inverter's rated power or exceeding the operating voltage range:

[0065]

[0066] Where A=P aco {1+C1(V dc -V dco )};B=P so {1+C2(V dc -V dco )}; C=C0{1+C3(V dc -V dco )};

[0067] The inverter efficiency is: 逆变器 =P ac / P dc ;

[0068] Where: P ac is the AC output power, W; P dc is the DC input power, W; V dc is the DC input voltage, V; P aco is the maximum AC power of the inverter under standard working conditions, W; P dco is the input DC power when the AC power reaches the standard condition, W; V dco is the input DC voltage when the AC power reaches the standard condition, (V max +V min ) / 2,V;P so is the starting DC power, i.e., the self-consumption DC power, W; C0, C1, C2 and C3 are the model empirical coefficients;

[0069] According to the solar irradiance distribution in the area, the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the operating voltage range is calculated using the weighted summation method:

[0070]

[0071] Where: δ—the time proportion of 5%, 10%, 20%, 30%, 50%, 100% of the rated power in the input power to the total input; η—the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the working voltage range (the working efficiency of the existing common string inverter is above 98%, and the power loss is about -1% to -2%);

[0072] Loss from inverter outlet to grid connection point:

[0073] This loss includes: AC cable loss and transformer loss. The AC cable loss is divided into single-phase transmission cable loss and three-phase cable loss. Transformer power loss is not considered when low-voltage grid connection is used.

[0074] Three-phase four-wire transmission line:

[0075] In the formula: I—line current R—resistance of each phase I0—neutral current R0—neutral resistance;

[0076] Single-phase transmission line:

[0077] The AC cable power loss is:

[0078] Transformer power loss: ΔP Z =ΔP+KQ ΔQ;

[0079] Where: ΔP Z —Comprehensive power loss (kW); ΔP—transformer active power loss (kW); ΔQ—transformer reactive power loss (kvar); K Q —reactive economic equivalent;

[0080] Transformer active power loss: ΔP=ΔP0+K T β 2 ΔP h ;

[0081] Where: ΔP—transformer active power loss (kW); ΔP0—transformer iron loss / no-load loss (kW); ΔP h —Transformer copper loss / rated load loss (kW); β—Transformer load factor; S e — Transformer rated capacity (kVA); S— Transformer load (kW); —Transformer secondary power factor; K T —Load fluctuation loss coefficient;

[0082] Transformer reactive power loss: ΔQ=Q0+K T β 2 Q h ; Q0=I0%·S e ;Q h =U h % S e ;

[0083] Where: ΔQ—transformer reactive power loss (kvar); Q0—transformer reactive power loss when no-load (kvar); Q h —Reactive power loss of transformer under rated load (kvar); I0%—Percentage of transformer no-load current; U h %—Transformer short-circuit voltage percentage (In addition, take K T =1.05; When the 6kV~10kV transformer of the urban power grid and industrial enterprise power grid takes the minimum load of the system, its reactive equivalent K Q =0.1kW / kvar; Transformer no-load loss ΔP0, rated load loss ΔP h ,I0%,U h %, which can be found in the technical manual. The empirical value of step-up transformer power loss is about -2%. )

[0084] (System availability: The reliability of equipment such as inverters, combiner boxes, cable connectors and photovoltaic brackets are important factors affecting system availability. The value of this coefficient is determined based on actual operating experience, generally 98% to 99%; PV module attenuation rate: The attenuation rate of monocrystalline silicon PV modules in the first year is about 3%).

[0085] To achieve the above objectives, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the photovoltaic power station power generation and optical power prediction algorithm are implemented.

[0086] To achieve the above objectives, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the photovoltaic power station power generation and optical power prediction algorithm.

[0087] The beneficial effects of the present invention are:

[0088] Based on factors such as regional longitude and latitude, altitude, meteorological conditions, house characteristics (orientation, shadow), roof characteristics (cement roof, color steel tile roof, rural household roof), etc., the present invention establishes optimization algorithms such as shadow, inclination, spacing, etc., formulates system selection and integrated optimization principles, and proposes a calculation theory that can accurately predict the power generation and power generation efficiency of distributed photovoltaic power stations on a monthly / seasonal / annual basis and on each physical slope. Guide and optimize the design links of distributed photovoltaic power stations, improve design solutions, and verify the rationality of designs. Provide more accurate power generation and power generation efficiency prediction data for feasibility studies, scientifically calculate the economic benefits and investment return rate of power stations, provide important theoretical basis for project establishment decisions, and improve the operation and management level of photovoltaic power stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 It is a flow chart of the photovoltaic power station power generation and light power prediction algorithm of the present invention. DETAILED DESCRIPTION

[0090] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0091] In the preferred embodiments of the present invention, those skilled in the art should note that the photovoltaic power station and the like involved in the present invention may be regarded as prior art.

[0092] Preferred embodiments.

[0093] like Figure 1 As shown, the present invention discloses a photovoltaic power station power generation and optical power prediction algorithm, comprising the following steps:

[0094] Step S1: Design a method for calculating predicted power generation. (When designing a solar photovoltaic power generation system, in order to absorb more solar radiation throughout the year, photovoltaic modules (arrays) are usually laid in a manner that faces the equator and is tilted at a certain angle to the ground plane (roof). Selecting different tilt angles will result in a large difference in the amount of solar radiation received by the array in each month.) By establishing a radiation model for the orientation and tilt angle (slope) of the photovoltaic modules, a formula for calculating predicted power generation is proposed:

[0095]

[0096] Where: E S —Irradiance under standard conditions; E p2 —Annual design forecast power generation (kW·h); P AZ —Installation capacity of components (kWp); G TX —Total annual solar radiation on slopes with orientation angles (kW·h / m 2 );K3—comprehensive efficiency coefficient;

[0097] Step S1.1: For the slope with an orientation angle, the total annual solar radiation H TX calculate:

[0098]

[0099] Where: H b is the horizontal direct radiation, H d is the scattered radiation on the horizontal surface, H0 is the solar radiation on the horizontal surface outside the atmosphere, R b is the ratio of direct radiation between the inclined surface and the horizontal surface, and β is the inclination angle;

[0100] Step S1.2: Calculation of comprehensive efficiency coefficient K3:

[0101] K3 includes 10 system parameters: relative transmittance loss, weak light loss, temperature loss, difference between actual component power and nominal power, component mismatch loss, collection cable loss, inverter loss, inverter outlet to grid connection point loss, system availability, and photovoltaic component attenuation rate; the value of K3 is the result of multiplying the 10 system parameters.

[0102] Specifically, for step S1.1:

[0103] Where: H is the total daily radiation on the horizontal surface; H hour is the average horizontal radiation (data provided by the Meteorological Bureau); Tsr and T ss The time of sunrise and sunset;

[0104]

[0105] In the formula: Let K sr =ω1,K ss =ω2; calculate the solar radiation H0 on the horizontal surface outside the atmosphere in one day,

[0106]

[0107] H b =HH d

[0108]

[0109] Description of relevant parameters:

[0110] —Latitude, the north-south angle of the equator, with north latitude being positive; (Geographic Information)

[0111] γ—Component slope azimuth, when the slope faces due south, it is 0, when it faces due east, it is negative, and when it faces due west, it is positive; -180°≤γ≤180°; (geographic information)

[0112] H hour —Hourly average radiation exposure on the horizontal surface (data provided by the Meteorological Bureau);

[0113] β—inclination angle, the angle between the plane and the horizontal plane; (design parameter)

[0114] δ—Declination angle, the angle between the sun’s rays and the equatorial plane at noon, with north being positive; -23.45°≤δ≤23.45°; (calculation)

[0115] α s ——The solar altitude angle, the angle between the horizontal plane and the line connecting the earth and the sun; (calculation)

[0116] ω—Hour angle, changes 15° every hour, negative in the morning, positive in the afternoon, and 0° at noon; (calculation)

[0117] And basic parameter calculation:

[0118] Solar declination angle δ and solar altitude angle α s calculate:

[0119] δ = 23.45 sin(2π (284 + N) / 365); N is the number of days;

[0120]

[0121] Sunrise and sunset angle K sr , K ss calculate:

[0122] Calculate the sunrise and sunset angle K of the inclined surface when the component azimuth angle γ = 0 s ;

[0123]

[0124] Calculate the sunrise and sunset angle K when the component azimuth is γ sr , K ss :

[0125]

[0126] Calculation of the radiation intensity I outside the atmosphere:

[0127] I = 1367 × (1 + 0.033 × cos (2π × N / 365)); N is the number of days.

[0128] More specifically, in the comprehensive efficiency coefficient K3:

[0129] For the relative transmittance loss:

[0130] The transmittance of conventional ultra-clear tempered glass is (approximately) 92%, and the transmittance of coated glass with anti-reflection film is as high as 96%. The relative transmittance loss of conventional ultra-clear tempered glass is (approximately) 2% of the total solar radiation, and that of high-transmittance, anti-reflection coated tempered glass is (approximately) 1%;

[0131] Low light loss:

[0132] Weak light loss refers to the loss of power generation caused by the reduction of conversion efficiency of components under weak light conditions. There will be certain differences in performance due to different solar radiation in different regions. The definition is that the irradiance is less than 1000W / m 2 The illumination is defined as weak light; Table 1 below is the test data of single crystal weak light effect:

[0133] Table 1

[0134]

[0135]

[0136] Where: η WL ——The power loss rate caused by weak light effect; δ 400W-600W ——The annual radiation intensity at the power station is 400W / m 2 -600W / m 2 The following proportions.

[0137] Power loss due to temperature change:

[0138] (Because the photovoltaic modules are directly exposed to the sun and the space is closed, the operating temperature of the silicon wafer in the optical module is very different from the ambient temperature provided by the weather station. Experiments have shown that:) Under STC conditions, the open circuit voltage temperature coefficient of the photovoltaic module monomer is (approximately) -0.33% / ℃, and the peak power loss rate is (approximately) -0.41% / ℃. Therefore, the model for estimating the battery operating temperature based on the ambient temperature is given as follows:

[0139] T m =E·e a+bWS +T n ;

[0140] Where: T m —PV module operating temperature (℃); E—environmental irradiance (W / m 2 ), provided by the Meteorological Bureau; a, b—(look up table) empirical values; T n —ambient temperature (℃); WS—wind speed (m / s);

[0141] Power loss at operating temperature of photovoltaic modules: η T =(T m -25)×λ T ;

[0142] Where: T m —Operating temperature (℃); λ T —Maximum power temperature influence coefficient (% / ℃) (can be obtained by looking up the table);

[0143] (Loss between the actual power of the module and the nominal power: The existing photovoltaic module technical specifications will mark the "standard test condition power tolerance" as 0 to +5, which means positive tolerance. The power range of a 270W module is between 270W and 275W to be qualified. According to the manufacturer's random inspection report, the actual power of the module is about 1% to 1.8% higher than the nominal power)

[0144] PV panel mismatch loss:

[0145] It refers to the group of strings under the same array or the same MPPT (maximum power point tracking) control. Due to individual differences, the output voltage is the sum of the series components, and the output current is the minimum value of the group of components, resulting in its total output power being less than the nominal power of the group of strings (according to the manufacturer's random inspection report, the mismatch loss of photovoltaic components is about 0 to -1%).

[0146]

[0147] Aggregation cable loss:

[0148] Refers to the DC cable loss. The DC side cable loss is calculated as follows, which is obtained from the resistivity formula. The DC cable resistance is:

[0149]

[0150] Where: ρ is the conductor resistivity, and its value is related to the ambient temperature of the conductor. ρ0 is the resistivity of the conductor at 0°C. a is the correction factor. T is the ambient temperature, °C. L is the conductor length, and S is the conductor cross-sectional area. The power loss and loss rate of the DC side cable are:

[0151]

[0152]

[0153] As an example: Due to the complex design of the power station site, when calculating the loss of the collection cable, the inverter with the farthest collection cable distance is selected as an example to calculate the loss of the collection cable. The cable uses 1*4mm2. The inverter with the farthest distance is the NB05 inverter, which is connected to 6 photovoltaic strings, each with 22 photovoltaic modules, and the rated power of the photovoltaic module is 265W. The total cable length is about 800m. The total cable resistance is approximately:

[0154]

[0155]

[0156] Inverter loss:

[0157] It includes two parts: the inverter's own loss, and the loss caused by exceeding the inverter's rated power or exceeding the operating voltage range:

[0158]

[0159] Where A=P aco {1+C1(V dc -V dco )};B=P so {1+C2(V dc -V dco )}; C=C0{1+C3(V dc -V dco )};

[0160] The inverter efficiency is: 逆变器 =P ac / P dc ;

[0161] Where: P ac is the AC output power, W; P dc is the DC input power, W; V dcis the DC input voltage, V; P aco is the maximum AC power of the inverter under standard working conditions, W; P dco is the input DC power when the AC power reaches the standard condition, W; V dco is the input DC voltage when the AC power reaches the standard condition, (V max +V min ) / 2,V;P so is the starting DC power, i.e., the self-consumption DC power, W; C0, C1, C2 and C3 are the model empirical coefficients;

[0162] According to the solar irradiance distribution in the area, the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the operating voltage range is calculated using the weighted summation method:

[0163]

[0164] Where: δ—the time proportion of 5%, 10%, 20%, 30%, 50%, 100% of the rated power in the input power to the total input; η—the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the working voltage range (the working efficiency of the existing common string inverter is above 98%, and the power loss is about -1% to -2%);

[0165] Loss from inverter outlet to grid connection point:

[0166] This loss includes: AC cable loss and transformer loss. The AC cable loss is divided into single-phase transmission cable loss and three-phase cable loss. Transformer power loss is not considered when low-voltage grid connection is used.

[0167] Three-phase four-wire transmission line:

[0168] In the formula: I—line current R—resistance of each phase I0—neutral current R0—neutral resistance;

[0169] Single-phase transmission line:

[0170] The AC cable power loss is:

[0171] Transformer power loss: ΔP Z =ΔP+K Q ΔQ;

[0172] Where: ΔP Z —Comprehensive power loss (kW); ΔP—transformer active power loss (kW); ΔQ—transformer reactive power loss (kvar); K Q —reactive economic equivalent;

[0173] Transformer active power loss: ΔP=ΔP0+K T β 2 ΔP h ;

[0174] Where: ΔP—transformer active power loss (kW); ΔP0—transformer iron loss / no-load loss (kW); ΔP h —Transformer copper loss / rated load loss (kW); β—Transformer load factor; S e — Transformer rated capacity (kVA); S— Transformer load (kW); —Transformer secondary power factor; K T —Load fluctuation loss coefficient;

[0175] Transformer reactive power loss: ΔQ=Q0+K T β 2 Q h ; Q0=I0%·S e ;Q h =U h % S e ;

[0176] Where: ΔQ—transformer reactive power loss (kvar); Q0—transformer reactive power loss when no-load (kvar); Q h —Reactive power loss of transformer under rated load (kvar); I0%—Percentage of transformer no-load current; U h %—Transformer short-circuit voltage percentage (In addition, take K T =1.05; When the 6kV~10kV transformer of the urban power grid and industrial enterprise power grid takes the minimum load of the system, its reactive equivalent K Q =0.1kW / kvar; Transformer no-load loss ΔP0, rated load loss ΔP h ,I0%,U h %, which can be found in the technical manual. The empirical value of step-up transformer power loss is about -2%. )

[0177] (System availability: The reliability of equipment such as inverters, combiner boxes, cable connectors and photovoltaic brackets are important factors affecting system availability. The value of this coefficient is determined based on actual operating experience, generally 98% to 99%; PV module attenuation rate: The attenuation rate of monocrystalline silicon PV modules in the first year is about 3%).

[0178] It is worth mentioning that the light power (power generation efficiency) can be obtained from the predicted power generation, and the present invention focuses on how to obtain the predicted power generation.

[0179] The present invention also discloses an electronic device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the photovoltaic power station power generation and optical power prediction algorithm when executing the program.

[0180] The present invention also discloses a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the photovoltaic power station power generation and optical power prediction algorithm are implemented.

[0181] Assume that the system parameters of K3 are shown in Table 2 below:

[0182] Table 2

[0183]

[0184] Then K3=0.99*0.9615*0.9312*1.015*0.995*0.9978*0.981*0.995

[0185] *0.99*0.975=0.8416.

[0186] It is worth mentioning that the technical features such as photovoltaic power stations involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field, and should not be regarded as the inventive point of the patent of this invention. The patent of this invention will not be further elaborated.

[0187] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A photovoltaic power station power generation and optical power prediction algorithm, characterized in that: The following steps are involved: Step S1: Design a method for calculating predicted power generation, establish an irradiation model based on the orientation and inclination of the photovoltaic modules, and propose a formula for calculating predicted power generation: Where: E S —Irradiance under standard conditions; E p2 —Annual design forecast power generation; P AZ —Component installation capacity; H TX —Total annual solar radiation on the slope with orientation angle; K3—comprehensive efficiency coefficient; Step S1.1: For the slope with an orientation angle, the total annual solar radiation H TX calculate: Where: H b is the horizontal direct radiation, H d is the scattered radiation on the horizontal surface, H0 is the solar radiation on the horizontal surface outside the atmosphere, R b is the ratio of direct radiation between the inclined surface and the horizontal surface, and β is the inclination angle; Step S1.2: Calculation of comprehensive efficiency coefficient K3: K3 includes 10 system parameters: relative transmittance loss, weak light loss, temperature loss, difference between actual component power and nominal power, component mismatch loss, collection cable loss, inverter loss, inverter outlet to grid connection point loss, system availability, and photovoltaic component attenuation rate; the value of K3 is the result of multiplying the 10 system parameters.

2. A photovoltaic power station power generation and optical power prediction algorithm according to claim 1, characterized in that: For step S1.1: Where: H is the total daily radiation on the horizontal surface; H hour is the average radiation exposure on the horizontal surface; T sr and T ss The time of sunrise and sunset; In the formula: Let K sr =ω1,K ss =ω2; calculate the solar radiation H0 on the horizontal surface outside the atmosphere in one day, H b =H-H d Description of relevant parameters: —Latitude, the north-south angle of the equator, with north latitude being positive; γ—the azimuth of the component slope, which is 0 when the slope faces due south, negative when it faces east, and positive when it faces west; -180°≤γ≤180°; H hour —average irradiation on horizontal surface; β—inclination, the angle between the plane and the horizontal plane; δ—declination angle, the angle between the sun’s rays and the equatorial plane at noon, with north being positive; -23.45°≤δ≤23.45°; α s ——The solar altitude angle is the angle between the horizontal plane and the line connecting the earth and the sun; ω—hour angle, which changes by 15° every hour, is negative in the morning, positive in the afternoon, and 0° at noon; And basic parameter calculation: Solar declination angle δ and solar altitude angle α s calculate: δ = 23.45 sin(2π (284 + N) / 365); N is the number of days; Sunrise and sunset angle K sr , K ss calculate: Calculate the sunrise and sunset angle K of the inclined surface when the component azimuth angle γ = 0 s ; K s =min(K s1 ,K s2 );; Calculate the sunrise and sunset angle K when the component azimuth is γ sr , K ss : Calculation of the radiation intensity I outside the atmosphere: I = 1367 × (1 + 0.033 × cos (2π × N / 365)); N is the number of days.

3. A photovoltaic power station power generation and optical power prediction algorithm according to claim 2, characterized in that: In the comprehensive efficiency coefficient K3: For the relative transmittance loss: The transmittance of conventional ultra-clear tempered glass is 92%, and the transmittance of coated glass with anti-reflection film is as high as 96%. The relative transmittance loss of conventional ultra-clear tempered glass is 2% of the total solar radiation, and that of high-transmittance, anti-reflection coated tempered glass is 1%; Low light loss: Weak light loss refers to the loss of power generation caused by the reduction of conversion efficiency of components under weak light conditions. There will be certain differences in performance due to different solar radiation in different regions. The definition is that the irradiance is less than 1000W / m 2 The light intensity is defined as low light; Power loss due to temperature changes: Under STC conditions, the open circuit voltage temperature coefficient of the photovoltaic module monomer is -0.33% / ℃, and the peak power loss rate is -0.41% / ℃. Therefore, the model for estimating the battery operating temperature based on ambient temperature is given as follows: T m =E·e a+bWS +T n ; Where: T m —PV module operating temperature; E—environmental irradiance; a, b—empirical values; T n —ambient temperature; WS—wind speed; Power loss at operating temperature of photovoltaic modules: η T =(T m -25)×λ T ; Where: T m —Operating temperature; T —Maximum power temperature influence coefficient; PV panel mismatch loss: It refers to the strings under the same array or the same MPPT control. Due to individual differences, the output voltage is the sum of the series components, and the output current is the minimum value of the string components, resulting in its total output power being less than the nominal power of the string; Aggregation cable loss: Refers to the DC cable loss. The DC side cable loss is calculated as follows, which is obtained from the resistivity formula. The DC cable resistance is: Where: ρ is the conductor resistivity, and its value is related to the ambient temperature of the conductor. ρ0 is the resistivity of the conductor at 0°C. a is the correction factor. T is the ambient temperature, °C. L is the conductor length, and S is the conductor cross-sectional area. The power loss and loss rate of the DC side cable are: Inverter loss: It includes two parts: the inverter's own loss, and the loss caused by exceeding the inverter's rated power or exceeding the operating voltage range: Where A=P aco {1+C1(V dc -V dco )};B=P so {1+C2(V dc -V dco )}; C=C0{1+C3(V dc -V dco )}; The inverter efficiency is: 逆变器 =P ac / P dc ; Where: P ac is the AC output power, W; P dc is the DC input power, W; V dc is the DC input voltage, V; P aco is the maximum AC power of the inverter under standard working conditions, W; P dco is the input DC power when the AC power reaches the standard condition, W; V dco is the input DC voltage when the AC power reaches the standard condition, (V max +V min ) / 2,V;P so is the starting DC power, i.e., the self-consumption DC power, W; C0, C1, C2 and C3 are the model empirical coefficients; According to the solar irradiance distribution in the area, the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the operating voltage range is calculated using the weighted summation method: Where: δ is the time proportion of 5%, 10%, 20%, 30%, 50%, 100% of the rated power in the input power to the total input; η is the efficiency of the loss caused by exceeding the rated power of the inverter or exceeding the operating voltage range; Loss from inverter outlet to grid connection point: This loss includes: AC cable loss and transformer loss. The AC cable loss is divided into single-phase transmission cable loss and three-phase cable loss. Transformer power loss is not considered when low-voltage grid connection is used. Three-phase four-wire transmission line: In the formula: I—line current R—resistance of each phase I0—neutral current R0—neutral resistance; Single-phase transmission line: The AC cable power loss is: Transformer power loss: ΔP Z =ΔP+K Q ΔQ; Where: ΔP Z —comprehensive power loss; ΔP—transformer active power loss; ΔQ—transformer reactive power loss; K Q —reactive economic equivalent; Transformer active power loss: ΔP=ΔP0+K T β 2 ΔP h ; Where: ΔP—transformer active power loss; ΔP0—transformer iron loss / no-load loss; ΔP h —Transformer copper loss / rated load loss; β—Transformer load factor; S e —transformer rated capacity; S—transformer load; —Transformer secondary power factor; K T —Load fluctuation loss coefficient; Transformer reactive power loss: ΔQ=Q0+K T β 2 Q h ; Q0=I0%S e ;Q h =U h %S e ; Where: ΔQ—transformer reactive power loss; Q0—transformer reactive power loss when no-load; Q h —Reactive power loss of transformer under rated load; I0%—Percentage of transformer no-load current; U h %—Transformer short-circuit voltage percentage.

4. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the photovoltaic power station power generation and optical power prediction algorithm as claimed in any one of claims 1 to 3 are implemented.

5. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the photovoltaic power station power generation and optical power prediction algorithm as claimed in any one of claims 1 to 3 are implemented.

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