CN106295034A - A kind of high accuracy scattering radiometer calculates method - Google Patents

Abstract

The invention discloses a kind of high accuracy scattering radiometer and calculate method, load both end voltage, and calculated level face solar global irradiance H, inclined-plane solar global irradiance H first with solar cell collection_t, horizontal plane scattering irradiance H_dData, the direct projection of existing Hay model, scattering computation model is utilized to calculate acquisition inclined-plane scattering irradiance respectively, both difference proportionality coefficients and the relation of time is tried to achieve followed by linear regression method, i.e. Hay model scattering radiation correction factor, thus revise Hay model scattering computation model, it is thus achieved that scattering radiometer calculates model in high precision.This scattering radiometer calculates method can go out scattering irradiance by accurate calculation, and for photovoltaic tracking system, optimum angle of incidence calculates, condenser system provides irradiance data accurately.

Description

A kind of high accuracy scattering radiometer calculates method

Technical field

The present invention relates to a kind of high accuracy scattering radiometer and calculate method, belong to photovoltaic system technical field.

Background technology

Day by day exhausted along with non-renewable energy resources, the regenerative resource such as water energy, wind energy, solar energy receives much concern, and too Sun can be inexhaustible, nexhaustible so that it is enjoys utilization.Solar thermal utilization such as butterfly, groove type solar, photovoltaic generation system Uniting, such as photovoltaic tracking system, optimum angle of incidence calculate, condenser system is required for solar irradiation data (particularly direct projection accurately Data) based on.And currently using Equations of The Second Kind anisotropic scattering radiation patterns widely is the basis at isotropic model On, the anisotropic scattering radiation patterns being modified for weather and sun altitude, this model calculates simple and convenient, has Certain use value.But this model is from isotropism correction, physical significance is indefinite, and precision is the highest, and physical definition is not Clearly, precision is the highest, therefore needs selected model is carried out the correction under different weather type.

Summary of the invention

The present invention provides a kind of high accuracy scattering radiometer to calculate model, solves existing scattering radiometer calculation model error bigger Problem, thus precisely predict generated energy.

For solving above-mentioned technical problem, the technical solution used in the present invention is as follows:

A kind of high accuracy scattering radiometer calculates method, comprises the following steps:

(1) irradiance data is gathered；

(2) scattering radiation correction factor is calculated；

(3) it is calculated revised scattering irradiance.

Three pieces of solar cells of aforesaid employing do irradiation sensor, one piece of horizontal positioned, one piece of inclination angle placement, one piece of level Place and add brake sack on the direction of sun direct irradiation, calculating irradiation according to based on solar cell external load both end voltage The nonlinear model of degree calculates corresponding horizontal plane solar global irradiance H, inclined-plane solar global irradiance H_t, the scattering irradiance H of horizontal plane_d, meter Calculation formula is as follows:

$H^i=\frac{0.07U_i-2.75\×{10}^{-12}(e^{\frac{308.99U_i}{T}}-1)\×{10}^4}{0.0646\×{U_i}^6-0.513\×{U_i}^5+1.514\×{U_i}^4-2.078\×{U_i}^3+1.626\×{U_i}^2-0.668\×U_i+1.352},i=1,2,3---\left(1\right)$

Wherein, as i=1, U₁For the solar cell external load both end voltage of horizontal positioned, H¹The corresponding total spoke of horizontal plane Illumination H, as i=2, U₂The solar cell external load both end voltage placed for inclination angle, H²Inclined surface solar global irradiance H_t, work as i When=3, U₃For horizontal positioned the solar cell external load both end voltage that adds brake sack on the direction of sun direct irradiation, H³The scattering irradiance H of corresponding horizontal plane_d。

Aforesaid calculating scatters radiation correction factor, comprises the following steps:

(2-1) scattering irradiance on inclined-plane is calculated according to scattering model；

Described scattering model is: scattering irradiance that the scattering irradiance on inclined-plane is exhaled by sun place CD and surrounding The equally distributed scattering irradiance of sky dome forms:

$H_{dt}=H_d\[\frac{H_b}{H_0}{R}_b+\frac{1}{2}(1-\frac{H_b}{H_0})(1+\cos s)\]---\left(3\right)$

Wherein, H_dtFor the scattering good fortune illumination on inclined-plane in scattering model, s is the inclination angle on inclined-plane；

H_bMeet:

H=H_d+H_b (2)

Wherein, H_bFor the direct projection irradiance of horizontal plane, H_dScattering irradiance for horizontal plane；

H₀Total solar irradiance in the horizontal direction of the atmosphere upper bound:

Wherein, α_sFor sun altitude, n is the place on same day natural law in a year；

R_bFor inclined-plane and the ratio of direct projection irradiance on horizontal plane:

$R_b=\frac{cos\mathrm{\θ}}{{\mathrm{cos\θ}}_Z}---\left(5\right)$

Wherein, θ_ZFor zenith angle, θ is solar incident angle；

Then, the scattering irradiance on scattering model calculating inclined-plane it is:

$H_{dt}=H_d\[\frac{H-H_d}{H_0}(R_b-\frac{1+\cos s}{2})+\frac{1+\cos s}{2}\]---\left(6\right);$

(2-2) scattering irradiance on inclined-plane is calculated according to direct projection model；

Described direct projection model is: the solar global irradiance that the solar cell of inclination receives is equal to scattering irradiance and direct projection irradiation Degree sum, then the scattering irradiance on inclined-plane is:

H′_dt=H_t-H_bt (8)

Wherein, H '_dtFor the scattering good fortune illumination on inclined-plane, H in direct projection model_btDirect projection irradiance for inclined-plane；

Owing to the direct projection irradiance of the sun is relevant with the angle of solar cell, therefore:

H_bt=H_b×R_b (7)

Then,

H′_dt=H_t-(H-H_d)×R_b(9)；

(2-3) calculate scattering radiation correction factor, define in scattering good fortune illumination and the direct projection model on inclined-plane in scattering model The difference proportionality coefficient of the scattering good fortune illumination on inclined-plane is scattering radiation correction factor Δ H_dt:

${\mathrm{\ΔH}}_{dt}=\frac{H_{dt}^{,}-H_{dt}}{H_{dt}}---\left(10\right);$

(2-4) scattering radiation correction factor and the functional relationship between the time are set up by the method for linear regression, specifically As follows:

Assuming that scattering radiation correction factor Δ H under different weather_dtIt is six functional relationships with time t:

ΔH_dt=b₁t⁶+b₂t⁵+b₃t⁴+b₄t³+b₅t²+b₆t+b₇ (11)

Wherein, coefficient b₁—b₇For unknown number,

Then it is calculated the coefficient b in formula (11) by the data of the method substitution different weather of linear regression₁— b₇, and then obtain scattering radiation correction factor and the functional relationship between the time.

Aforesaid revised scattering irradiance is:

H_Dt-revises=(Δ H_dt+1)H_dt (12)

Wherein, H_Dt-revisesFor the scattering irradiance on revised inclined-plane, H_D-revisesScattering irradiation for revised horizontal plane Degree.

The scattering radiometer of the present invention calculates method can go out scattering irradiance by accurate calculation, for photovoltaic tracking system, most preferably inclines Angle calculates, condenser system provides irradiance data accurately.

Accompanying drawing explanation

Fig. 1 is that the high accuracy scattering radiometer of the present invention calculates flow chart；

Fig. 2 is solar cell；

Fig. 3 is scattering radiation correction factor and the graph of a relation of time under different weather；

Fig. 4 is solar cell irradiation measuring instrument.

Detailed description of the invention

The invention will be further described below in conjunction with the accompanying drawings.Following example are only used for clearly illustrating the present invention Technical scheme, and can not limit the scope of the invention with this.

As it is shown in figure 1, the inventive method loads both end voltage, and the total spoke in calculated level face first with solar cell collection Illumination H, inclined-plane solar global irradiance H_t, horizontal plane scattering irradiance H_dData, utilize the direct projection of existing Hay model, scattering computation model Calculate respectively and obtain inclined-plane scattering irradiance H_dt, calculate followed by linear regression method and obtain the scattering radiation correction of Hay model Coefficient, thus revise Hay model scattering computation model, concrete calculation process is as follows:

1. irradiance data collection

Using three pieces of solar cells as shown in Figure 2 to do irradiation sensor, one piece of horizontal positioned, one piece of inclination angle place, one Block horizontal positioned also adds brake sack on the direction of sun direct irradiation.Solar cell produces photoproduction electricity after receiving solar radiation Stream, electric current flows through the resistance in loop so that it is two ends produce electric potential difference, calculates spoke according to based on battery external load both end voltage The nonlinear model of illumination calculates corresponding horizontal plane solar global irradiance H, inclined-plane solar global irradiance H_t, the scattering irradiance H of horizontal plane_d Data, computing formula is as follows:

$H^i=\frac{0.07U_i-2.75\×{10}^{-12}(e^{\frac{308.99U_i}{T}}-1)\×{10}^4}{0.0646\×{U_i}^6-0.513\×{U_i}^5+1.514\×{U_i}^4-2.078\×{U_i}^3+1.626\×{U_i}^2-0.668\×U_i+1.352},i=1,2,3---\left(1\right)$

Wherein, as i=1, U₁For the solar cell external load both end voltage of horizontal positioned, H¹The corresponding total spoke of horizontal plane Illumination H, as i=2, U₂The solar cell external load both end voltage placed for inclination angle, H²Inclined surface solar global irradiance H_t, work as i When=3, U₃For horizontal positioned the solar cell external load both end voltage that adds brake sack on the direction of sun direct irradiation, H³The scattering irradiance H of corresponding horizontal plane_d。

2. scattering radiation correction factor calculates

2-1) scattering model calculates inclined-plane scattering irradiance

In order to strengthen the silion cell absorption to sunlight, improve the performance of battery, often do at matte on silion cell surface Reason, effective suede structure makes visible ray repeatedly reflect at battery surface, reflects, and is substantially reduced silion cell surface to solar radiation Reflection, therefore arrive the solar global irradiance of battery surface and be approximately equal to scattering irradiance and direct projection irradiance sum:

H=H_d+H_b (2)

In formula, H_bFor the direct projection irradiance of horizontal plane, H_dScattering irradiance for horizontal plane.

The scattering computation model of the irradiatometer of present invention design uses and obtains Hay model based on isotropism correction, i.e. inclines The scattering irradiance that scattering irradiance above inclined-plane is exhaled by sun place CD is equally distributed with surrounding sky dome Scattering irradiance forms:

$H_{dt}=H_d\[\frac{H_b}{H_0}{R}_b+\frac{1}{2}(1-\frac{H_b}{H_0})(1+\cos s)\]---\left(3\right)$

In formula, H_dtInclined-plane for scattering model scatters good fortune illumination, and s is the inclination angle on inclined-plane,

H₀Total solar irradiance in the horizontal direction of the atmosphere upper bound:

In formula, α_sFor sun altitude, n is the place on same day natural law in a year；

R_bFor inclined plane and the ratio of direct solar radiation degree on horizontal plane:

$R_b=\frac{cos\mathrm{\θ}}{{\mathrm{cos\θ}}_Z}---\left(5\right)$

In formula, θ_ZFor zenith angle, θ is solar incident angle.

Then being calculated inclined-plane scattering irradiance by scattering model is:

$H_{dt}=H_d\[\frac{H-H_d}{H_0}(R_b-\frac{1+\cos s}{2})+\frac{1+\cos s}{2}\]---\left(6\right)$

2-2) direct projection model calculates inclined-plane scattering irradiance

Owing to the direct projection irradiance of the sun is relevant with the angle of solar cell, therefore:

H_bt=H_b×R_b (7)

The solar global irradiance that the solar cell tilted receives is approximately equal to scattering irradiance and direct projection irradiance sum, the most directly The inclined-plane scattering irradiance penetrating model is:

H′_dt=H_t-H_bt (8)

H_btFor the direct projection irradiance of inclined plane, H_dtInclined-plane for scattering model scatters good fortune illumination.

Then being calculated inclined-plane scattering irradiance by direct projection model is:

H′_dt=H_t-(H-H_d)×R_b (9)

H′_dtInclined-plane for direct projection model scatters good fortune illumination.

2-3) scattering radiation correction factor

Being calculated by above two method and obtain inclined-plane scattering irradiance, the difference proportionality coefficient trying to achieve both is scattering spoke Penetrate correction factor:

${\mathrm{\ΔH}}_{dt}=\frac{H_{dt}^{,}-H_{dt}}{H_{dt}}---\left(10\right)$

Irradiance data under different weather is carried out above-mentioned process, then scattering radiation correction factor Δ H_dtWith time t's Relation is as shown in Figure 3.

From figure 3, it can be seen that Δ H_dtAnd there is certain relation between t, and under different weather, relation is different, due to Δ H_dtIt is worth relatively small, in order to ensure precision, it is assumed here that Δ H under different weather_dtIt is six functional relationships with t:

ΔH_dt=b₁t⁶+b₂t⁵+b₃t⁴+b₄t³+b₅t²+b₆t+b₇ (11)

In formula, b₁—b₇For unknown number, the data here by the method substitution different weather of linear regression calculate formula In coefficient as shown in table 1.

Coefficient (× 10 in table 1 formula (10)³)

3. high accuracy scattering radiometer is calculated

General, as shown in Figure 4, it is by horizontal solar cell, inclined-plane for the irradiation measuring instrument with solar cell as sensor Solar cell is converted to the solar global irradiance on the solar global irradiance of level, inclined-plane after receiving solar radiation, calculated by Hay model and obtain Scattering irradiance, because model error in terms of calculating scattering radiation is excessive, therefore calculates the scattering radiancy obtained to Hay model It is modified, it is assumed that being calculated, by model, the inclined-plane scattering irradiance obtained is H_dt, the most revised scattering irradiance is:

H_Dt-revises=(Δ H_dt+1)H_dt (12)

In formula, H_Dt-revisesFor revised inclined-plane scattering irradiance, H_D-revisesFor revised horizontal plane scattering irradiance.

The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art For Yuan, on the premise of without departing from the technology of the present invention principle, it is also possible to make some improvement and deformation, these improve and deformation Also should be regarded as protection scope of the present invention.

Claims (4)

1. a high accuracy scattering radiometer calculates method, it is characterised in that comprise the following steps:

(1) irradiance data is gathered；

(2) scattering radiation correction factor is calculated；

(3) it is calculated revised scattering irradiance.

A kind of high accuracy scattering radiometer the most according to claim 1 calculates method, it is characterised in that use three blocks of sun electricity Irradiation sensor is done in pond, and one piece of horizontal positioned, one piece of inclination angle are placed, one piece of horizontal positioned on the direction of sun direct irradiation Adding brake sack, the nonlinear model according to calculating irradiance based on solar cell external load both end voltage calculates corresponding level Face solar global irradiance H, inclined-plane solar global irradiance H_t, the scattering irradiance H of horizontal plane_d, computing formula is as follows:

$H^i=\frac{0.07U_i-2.75\×{10}^{-12}(e^{\frac{308.99U_i}{T}}-1)\×{10}^4}{0.0646\×{U_i}^6-0.513\×{U_i}^5+1.514\×{U_i}^4-2.078\×{U_i}^2+1.626\×{U_i}^2-0.668\×U_i+1.352},i=1,2,3---\left(1\right)$

Wherein, as i=1, U₁For the solar cell external load both end voltage of horizontal positioned, H¹Corresponding horizontal plane solar global irradiance H, as i=2, U₂The solar cell external load both end voltage placed for inclination angle, H²Inclined surface solar global irradiance H_t, work as i=3 Time, U₃For horizontal positioned the solar cell external load both end voltage that adds brake sack on the direction of sun direct irradiation, H³Right Answer the scattering irradiance H of horizontal plane_d。

A kind of high accuracy scattering radiometer the most according to claim 2 calculates method, it is characterised in that described calculating scattering spoke Penetrate correction factor, comprise the following steps:

(2-1) scattering irradiance on inclined-plane is calculated according to scattering model；

Described scattering model is: the scattering irradiance that the scattering irradiance on inclined-plane is exhaled by sun place CD and surrounding sky The equally distributed scattering irradiance of dome forms:

$H_{dt}=H_d\[\frac{H_b}{H_0}{R}_b+\frac{1}{2}(1-\frac{H_b}{H_0})(1+\cos s)\]---\left(3\right)$

Wherein, H_dtFor the scattering good fortune illumination on inclined-plane in scattering model, s is the inclination angle on inclined-plane；

H_bMeet:

H=H_d+H_b (2)

Wherein, H_bFor the direct projection irradiance of horizontal plane, H_dScattering irradiance for horizontal plane；

H₀Total solar irradiance in the horizontal direction of the atmosphere upper bound:

Wherein, α_sFor sun altitude, n is the place on same day natural law in a year；

R_bFor inclined-plane and the ratio of direct projection irradiance on horizontal plane:

$R_b=\frac{cos\mathrm{\θ}}{{\mathrm{cos\θ}}_Z}---\left(5\right)$

Wherein, θ_ZFor zenith angle, θ is solar incident angle；

Then, the scattering irradiance on scattering model calculating inclined-plane it is:

$H_{dt}=H_d\[\frac{H-H_d}{H_0}(R_b-\frac{1+\cos s}{2})+\frac{1+\cos s}{2}\]---\left(6\right);$

(2-2) scattering irradiance on inclined-plane is calculated according to direct projection model；

Described direct projection model is: the solar global irradiance that the solar cell of inclination receives equal to scattering irradiance and direct projection irradiance it With, then the scattering irradiance on inclined-plane is:

H′_dt=H_t-H_bt (8)

Wherein, H '_dtFor the scattering good fortune illumination on inclined-plane, H in direct projection model_btDirect projection irradiance for inclined-plane；

Owing to the direct projection irradiance of the sun is relevant with the angle of solar cell, therefore:

H_bt=H_b×R_b (7)

Then,

H′_dt=H_t-(H-H_d)×R_b(9)；

(2-3) scattering radiation correction factor is calculated, inclined-plane in the scattering good fortune illumination on inclined-plane and direct projection model in definition scattering model Scattering good fortune illumination difference proportionality coefficient for scattering radiation correction factor Δ H_dt:

${\mathrm{\ΔH}}_{dt}=\frac{H_{dt}^{,}-H_{dt}}{H_{dt}}---\left(10\right);$

(2-4) scattering radiation correction factor and the functional relationship between the time are set up by the method for linear regression, specific as follows:

Assuming that scattering radiation correction factor Δ H under different weather_dtIt is six functional relationships with time t:

ΔH_dt=b₁t⁶+b₂t⁵+b₃t⁴+b₄t³+b₅t²+b₆t+b₇ (11)

Wherein, coefficient b₁—b₇For unknown number,

Then it is calculated the coefficient b in formula (11) by the data of the method substitution different weather of linear regression₁—b₇, enter And obtain scattering radiation correction factor and the functional relationship between the time.

A kind of high accuracy scattering radiometer the most according to claim 3 calculates method, it is characterised in that described revised scattered Penetrating irradiance is:

H_Dt-revises=(Δ H_dt+1)H_dt (12)

Wherein, H_Dt-revisesFor the scattering irradiance on revised inclined-plane, H_D-revisesScattering irradiance for revised horizontal plane.