JP2972596B2 - Power generation prediction method for photovoltaic power generation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating a power generation amount of a photovoltaic power generation system. More specifically, the present invention relates to a method for estimating a power generation amount of a photovoltaic power generation system that can easily and accurately predict a power generation amount of a photovoltaic power generation system at an arbitrary installation point.

[0002]

2. Description of the Related Art A photovoltaic power generation system that generates electric power by converting light energy of sunlight into electric energy can safely use inexhaustible energy despite the depletion of natural resources such as oil. Research and development are being actively pursued, and their use is being promoted.

[0003] In using such a solar power generation system, it is very important for the user how much the solar power generation system generates power at the installation site. Conventionally, the amount of power generated by the photovoltaic power generation system has been predicted based on, for example, measurement data from a weather station closest to the installation location of the system.

For example, FIG. 1 illustrates a prediction process of such a conventional power generation prediction method for a photovoltaic power generation system. In the conventional prediction method illustrated in FIG.
First, position information such as latitude and longitude of the installation location of the solar cell, the capacity of the photovoltaic system, the number of series-parallel solar cells corresponding to the capacity of the photovoltaic system, and the installation azimuth and inclination of the solar cell at the installation location From the corner, etc., it is decided what kind of solar power generation system is to be installed at what point. Then, the amount of generated power is predicted for the photovoltaic power generation system thus determined.

[0005] First, from the daily solar radiation data of the monthly average for each region by the weather station, data of the weather station divided area to which the installation site of the photovoltaic power generation system belongs is selected, and the global solar radiation intensity at the system installation site is selected. Get. Next, an operating temperature power generation amount of the photovoltaic power generation system is obtained by adding a temperature coefficient for each type of solar cell to the solar cell operating temperature calculated in advance. The solar cell operating temperature is calculated, for example, as an average of the published operating temperatures of each solar cell maker.

Then, a DC power generation amount is obtained from the operating temperature power generation amount, and an AC power generation amount is obtained from the DC power generation amount. The daily AC power generation amount thus obtained is a predicted value of the power generation amount of the photovoltaic power generation system. Further, the monthly power generation, the annual power generation, or the seasonal power generation can be obtained by multiplying the predicted daily power generation by the corresponding number of days.

[0007] As described above, the conventional method of estimating the amount of power generation of a photovoltaic power generation system predicts the amount of power generation based on data measured by a meteorological observatory. Although the power generation amount can be predicted relatively accurately, it is very difficult to accurately predict the power generation amount of a solar power generation system installed in an area other than the vicinity of the weather station.

[0008] Further, since the global irradiance greatly varies depending on the state of the opening of the sky viewed from the solar cell surface, the weather station obstructs the opening of the sky and obstructs a building or the like that generates scattered light. Various values are measured in a place where no object exists. However, the installation location of the solar cell by a general user is rarely in the surrounding environment where such obstacles do not exist. In other words, normally, a solar power generation system of a general user only has a point where direct light of sunlight and scattered light due to an obstacle or the like existing around the solar cell enter the solar cell surface, that is, only the direct light. Often, it is installed at a point affected by scattered light. Therefore, in order to accurately obtain the global solar radiation intensity to the solar cell, it is necessary to consider the direct solar radiation intensity by the direct light and the scattered solar radiation intensity by the scattered light.

However, in the conventional prediction method, as described above, the global solar irradiance is obtained by using only global solar irradiance data of a meteorological observatory by a measuring instrument installed at a point which is not much affected by scattered light. Therefore, unlike the surrounding environment of meteorological observing instruments, it is extremely difficult to accurately predict the amount of power generated by a solar power generation system installed at a point affected by direct light and scattered light. There was a problem that it was difficult.

Therefore, the present invention has been made in view of the above circumstances, and a photovoltaic power generation system capable of highly accurately predicting the amount of power generated by a photovoltaic power generation system at an arbitrary installation point for each weather. The purpose is to provide a method for estimating the amount of power generated by the system.

[0011]

Means for Solving the Problems] The present invention, as to solve the above problems, the power generation amount of the solar power generation systems to a method of predicting by region and weather, regional and atmospheric transmittance weather Measure separately in advance (step
1) In the area corresponding to the installation location of the solar power generation system
Atmospheric transmittance, extra-atmospheric normal solar radiation, air mass, and thickness by weather
Latitude of solar power system installation point and solar cell module
Using the azimuth and tilt angles of the
Calculate the solar radiation intensity (step 2) and
Sky solid angle measured at the pond module installation point
And cloud coefficient and specific coefficient b by area and weather by weather station
To calculate the scattered solar radiation intensity (step
3) To add these direct and scattered solar intensities
Obtains a more global solar radiation intensity (step 4), then the solar cell operating temperature by summing the regional date minimum temperature by value and weather stations multiplied by the specific coefficients c to the solar radiation intensity
Calculated (Step 5), commensurate with the solar cell operating temperature
A power generation amount operating temperature power generation amount calculated (Step 6), and
In addition, this operating temperature power generation amount is multiplied by a specific coefficient d.
After obtaining the DC power generation amount (step 7), the DC power generation amount is multiplied by the specific coefficient e to obtain the AC power generation amount .
(Step 8) and these steps 1 to
By performing step 8 at any time interval,
Providing power generation amount prediction method of photovoltaic power generation system characterized by predicting (claim 1) for every arbitrary time interval the amount of electric power generated by the electric system.

Further, the present invention provides the above-mentioned method,
Sum up each forecasted power generation at any time interval according to the weather
The daily power generation by weather (Claim 2) and the daily power generation by weather and monthly
Determining the weather another monthly power generation amount from the weather dates are the (claim 3) of Domo aspects thereof.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a method for predicting the power generation amount of a photovoltaic power generation system by region and by weather, wherein the atmospheric transmittance is calculated by region and by weather.
Measure in advance for each weather (step 1), and
Atmospheric transmittance by area weather corresponding to the installation location of the stem
And extra-atmospheric normal solar radiation, air mass and photovoltaic system
Latitude of installation point and azimuth and inclination of solar cell module
Calculate direct solar radiation intensity using oblique angles and the sun's trajectory in the sky
(Step 2) and installation of solar cell module
Sky solid angle measured at the point and the area by the meteorological observatory
By multiplying the cloud amount for each and the weather by the specific coefficient b
Scattered solar radiation intensity calculated (step 3), the solar radiation intensity determined by adding the scattering irradiance these direct solar radiation intensity
(Step 4) Then, a specific coefficient is assigned to the global solar radiation intensity.
Add the value multiplied by c and the daily minimum temperature for each region from the weather station
Obtains a solar cell operating temperature by Rukoto (Step 5),
An operating temperature power generation amount corresponding to the solar cell operating temperature is obtained (step 6) , and a DC power generation amount is obtained by multiplying the operating temperature power generation amount by a specific coefficient d.
(Step 7), the DC power generation amount is multiplied by a specific coefficient e.
Determine the alternator amount by kicking it (Step 8), And
And these steps 1 to 8 can be performed at arbitrary time intervals.
Each time, the amount of power generated by the photovoltaic power generation system is predicted at any time interval, and the amount of power generated by the photovoltaic power generation system at any installation point can be easily increased according to the weather. It has the effect that it can be predicted with accuracy.

[0014] According to a second aspect of the invention, any time a different Weather
Heaven By total each prospective power generation amount in between every interval
The present invention is characterized in that the daily power generation amount for each weather is obtained, and has the same operation as the invention according to claim 1. The third aspect of the present invention provides a daily power generation amount and energy
Monthly weather amount by elephant stand and monthly power generation by weather
It is obtained by and obtains the has the same effect as the effect of having the first aspect of the present invention.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
2 will be described. FIG. 2 shows a solar power generation system according to the present invention.
An example of the prediction process of the system power generation prediction method
It is a thing. First, the latitude of the solar cell
Location information such as background, prefecture and municipal names,
The capacity of the photovoltaic system, the capacity of this photovoltaic system
The number of solar cells in series and parallel
What type of azimuth and inclination angle
Where to install the solar power system
decide. The number of series-parallel
Pond module and inverter are announced by their respective manufacturers
Determined from performance values.

Then, at the installation point of the photovoltaic power generation system determined in this way, weather-specific, for example, fine weather,
Forecast power generation in four weathers: sunny, cloudy, and rainy. First, the atmospheric transmittance at the installation point of the photovoltaic power generation system for each weather is obtained as follows, for example. In advance, the slope global solar radiation intensity and slope scattered solar radiation intensity are measured separately at a plurality of points different from the point where the weather station is located, using the measured values of the slope global solar radiation intensity and the slope scattered solar radiation intensity,

[0017]

(Equation 1)

The direct sunlight on the slope is calculated by using the calculated value of the direct sunlight on the slope and the angle of incidence of the sunlight on the slope.

[0019]

(Equation 2)

The direct solar irradiance is then calculated, and the calculated direct solar irradiance, the extra-atmospheric irradiance and the air mass are used.

[0021]

(Equation 3)

Thus, the atmospheric transmittance for each region and each weather is calculated. By assigning the calculated atmospheric transmittance corresponding to the installation location and the weather of the photovoltaic power generation system to be predicted from the thus-calculated air transmittance for each region and each weather, the solar power generation system for the prediction target is assigned. Atmospheric permeability at each installation point is calculated. For example, Table 1 exemplifies the calculated atmospheric transmittance for each month in each region at the time of fine weather calculated in this manner.
Is an example of the atmospheric transmittance for each season for each weather and each region.

[0023]

[Table 1]

[0024]

[Table 2]

The areas are divided into northern and southern parts of Kyoto prefecture, Osaka prefecture, northern and southern parts of Hyogo prefecture, northern and southern parts of Wakayama prefecture, Shiga prefecture and Nara prefecture. In Table 1, the sunshine intensity on a slope is measured in each region when the weather is fine, and the air transmittance is calculated based on the sunshine intensity on the slope as described above, and the average value of the air transmittance for each month is calculated. It is shown. In Table 2, in each region, the atmospheric transmittance calculated on the basis of the total solar radiation intensity of the slope measured at the time of fine weather, fine weather, cloudy weather, and rainy season, in spring (March to May) and summer (June) ~ August), Autumn (September ~ 1)
The average values in January) and winter (December to February) are shown.

It should be noted that the calculated air permeability for each region and each weather is stored in a database, and when calculating the air permeability, the installation location of the photovoltaic power generation system to be predicted and the weather are input to handle them. May be determined. Next, the atmospheric transmittance at the installation location of the photovoltaic power generation system obtained as described above, the solar radiation outside the atmosphere, the air mass, the latitude of the installation location of the photovoltaic power generation system, Using the azimuth and inclination of the module and the sun's trajectory in the sky, the direct solar radiation intensity to the solar cell module is determined.

Further, using the solid angle of the sky measured at the installation point of the solar cell module and the cloud amount for each area and weather by the weather station, for example,

[0028]

(Equation 4)

Thus, the scattered solar radiation intensity to the solar cell module is calculated. As the cloud amount for each area, a value of an area corresponding to the installation location of the solar cell module is selected and used.
In addition, the sky solid angle can be easily obtained, for example, from a photographed image of a fisheye lens in the method of evaluating a shade already developed by the inventor of the present invention. here,
FIG. 3 illustrates the relationship between the cloud solid angle obtained from the sky solid angle and the cloud amount and the scattered solar radiation intensity. The sky solid angle is a value measured at a specific point in the southern part of Kyoto Prefecture, and the cloud amount is data of a weather station at a sunny day in the southern part of Kyoto corresponding to the point at which the sky solid angle was measured. As is clear from FIG. 3, the relationship between the solid angle of the cloud obtained from the solid angle of the sky and the cloud amount and the scattered solar radiation intensity can be represented by specific values determined for each region and each weather. The intensity can be calculated by the above equation using the single-sky solid angle, the cloud amount, and a specific value, that is, a coefficient.

Then, the total solar irradiance is obtained by adding the direct solar irradiance and the scattered solar irradiance, for example. As described above, in the prediction method of the present invention, in order to obtain the global solar radiation intensity from the direct solar radiation intensity by the direct light and the scattered solar radiation intensity by the scattered light, the conventional predictive method not considering the scattered light as described above. In addition, it is possible to more accurately obtain the global solar radiation intensity on the solar cell module. In addition, since the direct solar radiation intensity is obtained using the atmospheric transmittance obtained based on the values measured in a plurality of regions, and the scattered solar radiation intensity is also obtained using the sky solid angle measured at the installation point of the system, As described above, it is possible to more accurately predict the amount of power generated by the photovoltaic power generation system at an arbitrary installation point than the conventional prediction method using only the data at the measurement position of the weather station.

Before obtaining the direct solar radiation intensity necessary for obtaining the global solar radiation intensity, for example, it is necessary to use a photographed image of a fish-eye lens in the method of evaluating a shadow already developed by the inventor of the present invention. By determining the presence or absence of direct light to the solar cell surface from the positional relationship between the sun trajectory and the obstacle at the installation location of the solar cell, according to the presence or absence of the direct light, whether to determine the direct solar radiation intensity It may be determined. That is, for example, when it is determined that there is no direct light to the solar cell surface from the positional relationship between the sun trajectory obtained by using the captured image of the fish-eye lens and the obstacle in the above-described method for evaluating the shade, the direct solar radiation is determined. Without obtaining the intensity, proceed to the processing of the next scattered solar radiation intensity, obtain the total solar irradiance only from the scattered solar irradiance, and conversely, when it is determined that there is direct light to the solar cell surface, As described above, the direct solar radiation intensity and the scattered solar radiation intensity are obtained, and the total solar radiation intensity is obtained from the direct solar radiation intensity and the scattered solar radiation intensity. As described above, by incorporating the processing for determining the presence or absence of direct light using a fish-eye lens in the method of evaluating a shade already developed by the inventor of the present invention, a more accurate global solar radiation intensity can be obtained.

Next, the operating temperature of the solar cell is determined by using the global solar radiation intensity accurately obtained as described above and the daily minimum air temperature for each region by the weather station. As the daily minimum temperature, a value in an area corresponding to the installation location of the solar cell module is selected and used. This solar cell operating temperature is, for example,

[0033]

(Equation 5)

Can be calculated by Using the solar cell operating temperature, a power generation amount corresponding to the solar cell operating temperature, that is, an operating temperature power generation amount is obtained. This operating temperature power generation is, for example,

[0035]

(Equation 6)

Can be calculated by Then, from the operating temperature power generation amount and the coefficient in consideration of the resistance of the electric wire, the connection resistance, and the contamination of the solar cell module surface in the solar power generation system, for example,

[0037]

(Equation 7)

The amount of DC power generation is obtained by using the DC power generation amount and a coefficient in consideration of the conversion efficiency of the DC / AC converter.

[0039]

(Equation 8)

Thus, the AC power generation amount is obtained. The AC power generation amount thus obtained is the power generation amount of the solar power generation system. Actually, for example, the above-described prediction of the power generation amount for each region and each weather is performed at every arbitrary time interval, for example, every sunrise (5 o'clock) to sunset (19) every hour. To determine the amount of power generation by time,
The daily power generation is obtained by summing up the predicted power generation values for each hour. By predicting the amount of power generation at an arbitrary time interval in this way, more accurate prediction can be performed.

Then, a monthly power generation amount is obtained from the daily power generation amount for each weather and the number of monthly weather days by the weather station. The power generation amount for each season is obtained by adding the power generation amounts of the months corresponding to each season, and the annual power generation amount is obtained by adding the power generation amounts of each month.
Of course, the present invention is not limited to the above-described example, and it goes without saying that various aspects are possible in detail.

[0042]

As described in detail above, according to the present invention, a method for estimating the amount of power generation of a photovoltaic power generation system that can easily and accurately predict the amount of power generated by the photovoltaic power generation system at an arbitrary installation point for each weather. Is provided.

[Brief description of the drawings]

FIG. 1 is a diagram exemplifying a prediction process of a conventional power generation amount prediction method for a solar power generation system.

FIG. 2 is a diagram illustrating a prediction process of a power generation amount prediction method for a photovoltaic power generation system according to the present invention.

FIG. 3 is a diagram exemplifying a relationship between a cloud solid angle obtained from a sky solid angle and a cloud amount and a scattered solar radiation intensity;

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuji Nogawa 2-34 Honjo Higashi, Kita-ku, Osaka-shi, Osaka Kinden Co., Ltd. (56) References JP-A-9-113354 (JP, A) JP-A-5-66153 (JP, A) JP-A-8-36433 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02N 6/00 G01J 1/02

Claims (3)

(57) [Claims] 1. A power generation amount of the photovoltaic power generation system to a method of predicting by region and weather, local atmospheric transmittance
Measurement in advance (step 1)
Local weather conditions corresponding to the location of the solar power generation system
Atmospheric transmittance, extrasolar normal solar radiation, air mass and solar power
Latitude of system installation point and orientation of solar cell module
Direct solar radiation using angles and tilt angles and the sun's trajectory in the sky
Calculation (step 2) and the solar cell module
Sky angle and meteorological observatory measured at the installation point of the tool
Multiplied by the specific coefficient b and the amount of cloud by region and by weather
To calculate the scattered solar radiation intensity (step 3).
Seeking pyranometer strength by adding the scattering irradiance Tadashi Luo solar radiation intensity (step 4), then the total solar radiation intensity
Is multiplied by the specific coefficient c and the daily minimum temperature for each area by the weather station is added to obtain the solar cell operating temperature (step
-Up 5), power generation amount der commensurate with the solar cell operating temperature
Operating temperature power generation amount determined that (Step 6), further, after obtaining the current power generation amount by multiplying the specific coefficient d in the <br/> operating temperature power generation amount (step 7), specific to the DC power generation amount
The AC power generation amount is obtained by multiplying by the coefficient e (step
8) and these steps 1 to 8 are optional
The solar power generation system
A power generation amount prediction method for a photovoltaic power generation system, wherein the power generation amount is predicted at an arbitrary time interval. 2. Prediction at each arbitrary time interval according to weather
The method for predicting the amount of power generation of a photovoltaic power generation system according to claim 1, wherein the amount of power generation is summed to determine the amount of daily power generation for each weather . 3. Daily power generation by weather and monthly by weather station
3. The method according to claim 2, wherein a monthly power generation amount for each weather is obtained from each of the weather days .