JPWO2017221462A1 - Power generation amount estimation device for solar cell, power generation amount estimation method, and power generation amount estimation program - Google Patents

Abstract

The data acquisition unit 131 acquires measurement data of the amount of solar radiation incident on the solar cell. The conversion efficiency correction unit 132 performs the first correction processing of the conversion efficiency using the acquired solar radiation amount and the first dependence relationship between the solar cell conversion efficiency and the solar radiation amount derived in advance, and the solar energy derived in advance. At least one of a second dependency between the conversion efficiency of the battery and the incident angle of sunlight and a second correction process of the conversion efficiency using the incident angle estimated based on the sun trajectory is performed. The power generation amount estimation unit 135 estimates the power generation amount of the solar cell based on the acquired solar radiation amount and the corrected conversion efficiency.

Description

  The present invention relates to a power generation amount estimation device for a solar cell, a power generation amount estimation method, and a power generation amount estimation program for estimating the power generation amount of a solar cell based on the amount of solar radiation and the conversion efficiency.

  In recent years, solar power generation systems have become widespread, and many manufacturers manufacture solar cell panels. As performance evaluation of a solar cell, the method of actually installing a solar cell and measuring an electric power generation amount is used widely. For example, a plurality of types of solar cells may be installed at the same place to compare the amount of power generation of each solar cell.

Further, one of the performance evaluations of solar cells is the JIS 8912 and JIS 8913 standards. According to JIS 8912 and JIS 8913 standards, the energy conversion efficiency of a solar cell is evaluated under the conditions of irradiance = 1 sun (1 kW / m ² ) and temperature = 25 ° C. In addition, in JIS 8912 and JIS 8913, it is required to uniformly irradiate simulated solar light used for performance evaluation of a solar cell in the plane of the solar cell, and in order to make light incident vertically to the solar cell, the incident angle = 0 ° It becomes. The energy conversion efficiency (hereinafter simply referred to as conversion efficiency) is a value obtained by dividing the output power (W) of the solar cell by the incident light energy (W). The conversion efficiency of a solar cell is temperature dependent (see, for example, Patent Document 1). Furthermore, the conversion efficiency of the solar cell also depends on the irradiance and incident angle of sunlight.

JP, 2015-070640, A

  The conversion efficiency of the solar cell under the actual driving environment is lower than the conversion efficiency derived based on the JIS 8913 standard due to the effects of the irradiance of sunlight, the incident angle, and the dependence on the temperature of the solar cell. Therefore, the amount of power generation actually measured is lower than the amount of power generation calculated by multiplying the conversion efficiency on the specification by the amount of solar radiation.

  Since the amount of power generation actually measured is derived as one value entangled with effects such as the irradiance of sunlight, the incident angle, and the temperature of the solar cell, the dependency on the irradiance, the incident angle, and the temperature Can not separate. Therefore, it is difficult to accurately analyze the factors that the irradiance, incident angle, and temperature give to the amount of power generation.

  The present invention has been made in view of these circumstances, and an object thereof is to provide a solar cell power generation amount estimation device, power generation amount estimation method, and power generation amount estimation program capable of precisely analyzing factors affecting the power generation amount of a solar cell. To provide.

  In order to solve the above problems, the power generation amount estimation device for a solar cell according to an aspect of the present invention includes a data acquisition unit that acquires measurement data of the amount of solar radiation incident on the solar cell; A first dependency between the conversion efficiency and the amount of solar radiation, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and the conversion efficiency of the solar cell and the incident angle of sunlight which are derived in advance A conversion efficiency correction unit that executes at least one of the second dependence processing of the second conversion processing using the incident angle estimated based on the sun trajectory, the acquired solar radiation amount, and And a power generation amount estimation unit configured to estimate a power generation amount of the solar cell based on the corrected conversion efficiency.

  According to the present invention, it is possible to precisely analyze factors that affect the amount of power generation of a solar cell.

It is a figure which shows the connection relation of the electric power generation amount estimation apparatus which estimates the electric power generation amount electric-power-generated by the solar cell. It is a figure which shows the structural example of the electric power generation amount estimation apparatus based on embodiment of this invention. FIGS. 3 (a) to 3 (f) are diagrams showing an example of direct solar radiation and scattered solar radiation. It is a flowchart which shows the flow of the electric power generation amount estimation process using a 2nd electric power generation amount estimation model. FIGS. 5 (a) and 5 (b) are graphs showing the amount of power generation of the solar cell installed at a certain place in the Kinki region. FIGS. 6 (a) and 6 (b) are graphs showing the ratio of the weather in the installation place of the solar cell in one year, and the ratio of the estimated power generation by another weather in the one year. FIGS. 7 (a) to 7 (d) are graphs showing the estimated power generation amount, incident angle loss amount, irradiance loss amount, and temperature loss amount of the solar cell in one year classified by weather. It is a figure which shows the graph which shows the ratio of the power generation estimated according to the season in 1 year of a solar cell. FIGS. 9 (a) to 9 (d) are graphs showing the estimated power generation amount, incident angle loss amount, irradiance loss amount, and temperature loss amount of the solar cell in one year classified by season.

  FIG. 1 is a diagram showing a connection relationship of a power generation amount estimation device 10 for estimating a power generation amount generated by a solar cell 1. The power generated by the solar cell 1 is output to the power converter 2. The power conversion device 2 is a power conditioner system (PCS) that converts DC power input from the solar cell 1 into AC power and outputs the AC power to the grid 3. The power conversion device 2 may supply the converted AC power to a load (not shown).

  Power converter 2 includes a boost chopper (not shown) and an inverter (not shown). The boost chopper performs MPPT (Maximum Power Point Tracking) control so that the power generated by the solar cell 1 becomes the maximum power point (optimum operating point). Specifically, according to the hill climbing method, the operating point voltage is changed with a predetermined step width to search for the maximum power point, and control is performed so that the output power of the solar cell 1 maintains the maximum power point. The inverter converts the DC power after MPPT control into AC power and outputs it to the grid 3.

  The power conversion device 2 measures the input voltage and the input current, and multiplies the two to measure the amount of power generation of the solar cell 1. In the present embodiment, the measured power generation amount is output to the measurement data storage device 4.

  In the vicinity of the solar cell 1, a solar radiation sensor 1a is installed parallel to the horizontal plane. For example, a full ephemeris can be used as the sunshine sensor 1a. The solar radiation sensor 1 a measures the amount of solar radiation (= the amount of solar radiation energy), and outputs the measured amount of solar radiation to the measurement data storage device 4.

  A temperature sensor 1 b is installed on the back of the panel of the solar cell 1. For example, a thermocouple can be used for the temperature sensor 1b. A thermistor may be incorporated in the panel of the solar cell 1. The temperature sensor 1 b measures the temperature of the solar cell 1 (hereinafter referred to as a drive temperature), and outputs the measured drive temperature to the measurement data storage device 4.

  The measurement data storage device 4 stores measurement data of the amount of solar radiation input from the solar radiation sensor 1a and the drive temperature input from the temperature sensor 1b. For example, a general data logger can be used as the measurement data storage device 4. The measurement data storage device 4 may be installed independently of the power conversion device 2 or may be incorporated in the power conversion device 2.

  For example, the measurement data storage device 4 stores measurement data of the amount of solar radiation and the driving temperature that are input at predetermined intervals (for example, in one minute units). In the present embodiment, in order to compare and verify the power generation amount estimated by the power generation amount estimation device 10 and the power generation amount actually measured by the power conversion device 2 (hereinafter referred to as actual power generation amount) An example of storage by the measurement data storage device 4 is assumed. Note that the storage of the measured power generation amount in the measurement data storage device 4 may be omitted.

  The measurement data storage device 4 periodically transmits the held measurement data to the power generation amount estimation device 10. FIG. 1 shows an example in which the measurement data storage device 4 and the power generation amount estimation device 10 are connected to the same network 5. Although the Internet is assumed as the network 5 in this specification, a dedicated line may be used.

  FIG. 2 is a diagram showing a configuration example of the power generation amount estimation device 10 according to the embodiment of the present invention. A general information processing apparatus can be used as the power generation amount estimation apparatus 10. For example, a PC, a server, a tablet, a smartphone, or the like can be used.

  The power generation amount estimation apparatus 10 includes a communication unit 11, a media insertion unit 12, a control unit 13, a console unit 14, and a storage unit 15. The control unit 13 includes a data acquisition unit 131, a conversion efficiency correction unit 132, an incident angle estimation unit 133, a direct dispersion separation unit 134, a power generation amount estimation unit 135, and a loss amount estimation unit 136. The configuration of the control unit 13 can be realized by cooperation of hardware resources and software resources, or hardware resources only. As hardware resources, analog elements, microcomputers, DSPs, ROMs, RAMs, FPGAs, and other LSIs can be used. Programs such as operating systems and applications can be used as software resources. The storage unit 15 stores various programs and various data. The storage unit 15 can use a ROM and a RAM.

  The communication unit 11 executes communication processing of data transmitted and received via the network 5. A removable media (for example, a memory card, an optical disk, a removable HDD, a removable SSD) is inserted into the media insertion unit 12, and data is read from the removable media. Or write data to removable media.

  For example, the measurement data in the measurement data storage device 4 is written to a removable medium at the installation location of the solar cell 1, and the measurement data is read into the power generation amount estimation device 10 by inserting the removable medium into the media insertion unit 12. Can. This method is used when the measurement data storage device 4 is not connected to the network 5 and is operating in a stand-alone manner.

  The data acquisition unit 131 acquires measurement data of the solar radiation amount and the drive temperature of the solar cell 1 from the communication unit 11 or the media insertion unit 12. When the user manually inputs the measurement data from the console unit 14, the measurement data is acquired from the console unit 14.

  The amount of power generation of the solar cell 1 can be measured based on the voltage and current input from the solar cell 1 to the power conversion device 2. Since this measurement method measures the physical quantity after being converted from light energy to electrical energy, it is basically impossible to analyze light or heat. Since the values of voltage and current to be measured are values after the combined factors of light and heat are involved, exact factor analysis can not be performed.

  Therefore, in the present embodiment, the amount of power generation of the solar cell 1 is estimated based on the light energy and the driving temperature before being converted into electric energy. In this estimation, the total solar radiation amount and the driving temperature of the solar cell 1 are used as site data (installation condition data). Irradiance dependency, incident angle dependency, and temperature dependency are used as device characteristics of the solar cell 1.

As evaluation of the device characteristic of the solar cell 1, JIS8912 and JIS8913 standards are used as standard standards. According to JIS8912 and JIS8913 standards, the solar cell module is irradiated with light of 1 sun (1 kW / m ² ) vertically at a temperature environment of 25 ° using a solar simulator, and the output voltage of the solar cell module The output current is measured to determine the conversion efficiency of the solar cell module. In this evaluation, a solar simulator device for irradiating light of the conditions is used as a simulated solar light source. Usually, each solar cell manufacturer describes the conversion efficiency obtained by the evaluation in a catalog or a specification. Hereinafter, this conversion efficiency is referred to as conversion efficiency under standard conditions.

  The conversion efficiency under standard conditions does not take into account the dependence on irradiance, angle of incidence and temperature. Therefore, in the present embodiment, the dependence of the conversion efficiency of the solar cell 1 on the irradiance, incident angle, and temperature is considered. The dependence of the conversion efficiency of the solar cell 1 on the irradiance is mainly due to the structure of the photodiode (PN structure, PIN structure, etc.) and the material constituting the solar cell module. The dependence of the conversion efficiency of the solar cell 1 on the incident angle is mainly due to the characteristics of the antireflective film (AR coat) attached to the panel surface and the optical structure of the solar cell module.

  In order to verify the dependence of the conversion efficiency and irradiance of the solar cell module, the verifier measures the output voltage and output current of the solar cell module each time the irradiance is changed using a solar simulator, and the solar cell module Find the conversion efficiency of For example, a filter is interposed between the light source and the solar cell module to adjust the illuminance emitted to the solar cell module. By using an acrylic plate for the filter, the irradiance can be reduced by any amount without changing the spectrum.

Perpendicularly to the solar cell module under the environment of temperature = 25 ° ^C., and irradiated with multiple levels of light between the ^{0kW / m 2 ~1kW / m 2} , obtaining the conversion efficiency at each level. The calculated variable efficiency values are normalized with the conversion efficiency of standard conditions (irradiance = 1 kW / m ² , incident angle = 0 °, temperature = 25 ° C.) as 1. Hereinafter, the value of the conversion efficiency after the normalization is referred to as an irradiation dependent coefficient E (I) of the conversion efficiency.

  Based on the irradiation dependence coefficients E (I) of a plurality of points obtained by the above verification, an approximate curve is derived with the irradiance I as an explanatory variable and the illuminance dependence coefficient E (I) as a target variable. For example, it approximates by the quartic function shown in the following (Formula 1). Basically, it becomes a downward-sloping curve in which the illuminance dependence coefficient E (I) decreases as the irradiance I decreases.

E (I) = aI ⁴ + bI ³ + cI ² + dI + e (Equation 1)

  Next, in order to verify the dependence of the conversion efficiency and the incident angle of the solar cell module, the verifier changes the incident angle and measures the output voltage and output current of the solar cell module each time using a solar simulator. Determine the conversion efficiency of the module. For example, using a jig capable of adjusting the angle of the solar cell module, the relative angle of the solar cell module with respect to the light source is adjusted. A jig capable of adjusting the angle of the light source may be used.

The solar cell module is irradiated with light at a plurality of incident angles between 0 ° and 90 ° (irradiance at an incident angle of 0 ° = 1 kW / m ² ) under an environment of temperature = 25 ° C., and the conversion efficiency at each angle Ask for The value of the variable efficiency thus determined is normalized with the conversion efficiency of the solar cell module under standard conditions (irradiance = 1 kW / m ² , incident angle = 0 °, temperature = 25 ° C.) as 1. Hereinafter, the conversion efficiency after this normalization is referred to as an incident angle dependent coefficient E (θ) of the conversion efficiency.

  Based on the incident angle dependent coefficients E (θ) of a plurality of points obtained by the above verification, an approximate curve with the incident angle θ as an explanatory variable and the incident angle dependent coefficient E (θ) as an objective variable is derived. For example, it approximates by the quartic function shown in the following (Formula 2). Basically, it becomes a downward-sloping curve in which the incident angle dependent coefficient E (θ) decreases as the incident angle θ increases.

E (θ) = aθ ⁴ + bθ ³ + cθ ² + dθ + e (Equation 2)

  Next, in order to verify the dependence of the conversion efficiency and temperature of the solar cell module, the verifier measures the output voltage and output current of the solar cell module each time the temperature is changed using a solar simulator, Find conversion efficiency. For example, the solar cell module is heated by a heater, and the heating temperature is adjusted.

In a state where light (irradiance = 1 kW / m ² ) is irradiated perpendicularly to the solar cell module, the solar cell module is heated at a plurality of temperatures, for example, between 25 ° C. and 65 ° C., and conversion efficiency at each temperature is determined. The value of the variable efficiency thus determined is normalized with the conversion efficiency of the solar cell module under standard conditions (irradiance = 1 kW / m ² , incident angle = 0 °, temperature = 25 ° C.) as 1. Hereinafter, this conversion efficiency after normalization is referred to as a temperature-dependent coefficient f (t) of conversion efficiency.

  Based on the temperature dependent coefficients E (t) of a plurality of points obtained by the above verification, an approximate straight line is derived with the temperature t as an explanatory variable and the temperature dependent coefficient f (t) as an objective variable. For example, it approximates with a linear function shown in the following (formula 3). Basically, the temperature dependence coefficient f (t) decreases as the temperature t rises, and the temperature becomes a downward straight line. The temperature t is also used outside the temperature range used in the measurement.

f (t) = at + b (Equation 3)
In addition, a, b, c, d and e in the above (formula 1) to (formula 3) are independent coefficients.

  At present, among the three evaluation parameters (device characteristics) of the conversion efficiency of the solar cell module, the temperature belonging to the thermal field is evaluated by an external evaluation organization such as JET, but the irradiance and incident angle belonging to the optical field are evaluated It has not been.

  At present, as evaluation of the solar cell 1 under actual use environment, collecting and analyzing hourly actual measurement power generation data is performed. The total solar radiation (direct sunlight + scattered solar radiation) under actual use environment shows different values depending on the weather, longitude / latitude, and time.

  From the actually measured power generation data by time, it is not possible to analyze individually the degree of influence of each factor of irradiance, incident angle and drive temperature on the power generation. On the other hand, from the power generation amount estimated based on the sunlight according to the present embodiment, the degree of influence of the irradiance, the incident angle, and the driving temperature on the power generation amount can be analyzed individually.

  In the first power generation amount estimation model according to the present embodiment, the conversion efficiency η (I, θ, t) of the solar cell 1 is determined using the following (Equation 4).

η (I, θ, t) = _{0 0} * E (I) * E (θ) * f (t) (Equation 4)
η ₀ is the conversion efficiency under standard conditions.

If the dependency on the irradiance I, incident angle θ and temperature t is not taken into account, E (I) = E (θ) = f (t) = 1, and the conversion efficiency η ₀ under the standard conditions is used as it is .

  For the irradiance I, measurement data of the amount of solar radiation can be used. For the temperature t, measurement data of the drive temperature can be used. The incident angle θ can be calculated based on the installation position (longitude and latitude) of the solar cell 1, the date and time, and the installation angle of the light receiving surface of the solar cell 1. Specifically, the sun's orbit is calculated based on longitude, latitude, and date. Based on the solar orbit, the position (altitude / orientation) of the sun at the measurement time of the solar radiation amount and the driving temperature is specified. From the relationship between the specified position of the sun and the installation angle of the light receiving surface of the solar cell 1, the incident angle θ at each measurement time is calculated.

  When the determined conversion efficiency η (I, θ, t) is multiplied by the measured solar radiation amount I and the total light reception area C of the solar cell 1, the power generation amount W is estimated as shown in the following (Equation 5) Can.

  W = C * I * η (I, θ, t) (5)

  Next, a second power generation amount estimation model according to the present embodiment in which the behavior of sunlight is considered will be described. The total solar radiation can be separated into direct solar radiation and scattered solar radiation (also called sky solar radiation). The direct solar radiation amount is light which directly reaches the solar cell 1 from the sun and has a directional component. The directional component changes with the position of the sun moving with time. The amount of scattered solar radiation is light scattered by particles in the atmosphere such as clouds, and is light reaching the solar cell 1 from all directions. The amount of scattered solar radiation has no directional component.

  FIGS. 3 (a) to 3 (f) are diagrams showing an example of direct solar radiation and scattered solar radiation. Gray arrows indicate direct solar radiation and black arrows indicate scattered solar radiation. The thickness of the arrow indicates the absolute amount of solar radiation. As shown in FIGS. 3 (a) to 3 (f), in direct sunlight, the amount of solar radiation decreases in the morning and in the evening when the altitude of the sun S decreases. In the morning and evening, the angle of incidence of direct sunlight increases. The incident angle is determined by the relative relationship with the light receiving surface of the solar cell 1. Therefore, if the movable mechanism capable of adjusting the direction of the light receiving surface of the solar cell 1 is used, it is possible to prevent the incident angle from being largely deviated from the vertical. On the other hand, the amount of scattered solar radiation is largely influenced by the position and amount of the cloud C, and the influence by the position of the sun S is relatively small.

In the second power generation amount estimation model of the behavior of sunlight, the power generation amount of the solar cell 1 is obtained separately from the power generation amount based on the direct solar radiation amount and the power generation amount based on the scattered solar radiation amount. As the premise, it is necessary to separate the measured total solar radiation amount Ig into the direct solar radiation amount Ib and the scattered solar radiation amount Id. For direct scattering separation of total solar radiation, for example, Erbs model shown in the following (Formula 6) and (Formula 7) can be used. Kt is sunny index can be calculated by global solar radiation Ig / air outside global solar radiation Ig _0.

When Kt ≦ 0.22
Id = Ig (1.0-0.09 Kt)
When 0.22 <Kt ≦ 0.80
^{Id = Ig (0.9511-0.1604Kt + 4.388Kt 2} -16.638Kt 3 + 12.366Kt 4)
When Kt> 0.80
Id = 0.165 Ig ... (Equation 6)
Ib = Ig-Id (7)

  Note that other models such as the METPV-3 model may be used instead of the Erbs model.

  In the second power generation amount estimation model, the conversion efficiency 下 記 of the solar cell 1 is divided into the conversion efficiency ηd for the scattering component and the conversion efficiency ηb for the direct achievement component as shown in the following (Equation 8) and (Equation 9) .

η d (I, t) = _{0 0} * E (Id) * f (t) (Equation 8)
η b (I, θ, t) = _{0 0} * E (Ib) * E (θ) * f (t) (9)

  The term E (θ) is eliminated because there is no directional component in the diffuse solar radiation. In the second power generation amount estimation model, the conversion efficiency η d (I, t) for scattered components, the amount of scattered solar radiation Id, the conversion efficiency η b (I, θ, t) for direct achievement, the amount of direct solar radiation Ib, the total light reception area C Based on the equation (10) below, the power generation amount W can be estimated.

W = C * {Id * d d (I, t) + Ib * b b (I, θ, t)} (10)
When the unit time of the solar radiation amount measurement is one minute, the power generation amount W can be estimated every minute. The power generation amount WWm of one day can be estimated by accumulating the power generation amount W of every minute for one day, and the power generation amount WWd of one year can be estimated by accumulating the power generation amount WWm of one day for one year.

  FIG. 4 is a flowchart showing a flow of power generation amount estimation processing using the second power generation amount estimation model. First, the data acquisition unit 131 acquires measurement data of the total solar radiation amount and the drive temperature (S10). The incident angle estimation unit 133 calculates the solar orbit based on the lightness / latitude of the installation position of the solar cell 1 and the date (S11). The incident angle estimation part 133 estimates an incident angle based on the calculated solar orbit, measurement time, and the installation angle of the solar cell 1 (S12). The direct scattering separation unit 134 separates the total solar radiation amount into a direct solar radiation amount and a scattered solar radiation amount using a predetermined direct scattering separation model (for example, an Erbs model) (S13).

  The conversion efficiency correction unit 132 corrects the conversion efficiency under the standard conditions using the amount of scattered solar radiation, the illuminance-dependent coefficient, the driving temperature, and the temperature-dependent coefficient to calculate the conversion efficiency of the scattered solar radiation (S14). In addition, the conversion efficiency correction unit 132 corrects the conversion efficiency under the standard conditions using the amount of direct solar radiation, the illuminance dependency coefficient, the incident angle, the incident angle dependent coefficient, the driving temperature, and the temperature dependent coefficient to convert direct sunlight. The efficiency is calculated (S15). The power generation amount estimation unit 135 estimates the power generation amount of the solar cell 1 based on the scattered solar radiation amount, the scattered solar radiation conversion efficiency, the direct solar radiation amount, the direct solar radiation conversion efficiency, and the light receiving area of the solar cell 1 S16).

  The loss amount estimation unit 136 estimates the loss amount due to the solar radiation amount, the incident angle or the drive temperature of the estimated power generation amount (S17). As shown in the following (formula 11), the loss amount LI caused by the amount of solar radiation is the amount of power generation calculated by the above (formula 10), the term of E (Id) in the above (formula 8), and the above (formula 9) It can be estimated by the difference from the power generation amount calculated with the term of E (Ib) of 1.

  LI = C * {Id * η d (I, t) + Ib * η b (I, θ, t)}-C * {Id * η d (t) + Ib * η b (θ, t)} (11)

  As shown in the following (formula 12), the amount of loss Lθ caused by the incident angle is the amount of generated power calculated by the above (formula 10) and the amount of generated power calculated as the term E (θ) of the above (formula 9) is 1. And the difference between

  Lθ = C * {Id * ηd (I, t) + Ib * ηb (I, θ, t)}-C * {Id * ηd (I, t) + Ib * ηb (I, t)} (Expression 12)

  As shown in the following (Equation 13), the loss amount Lt caused by the driving temperature is calculated by the above (Equation 10), and the terms of f (t) of the (Equation 8) and (Equation 9) It can estimate by the difference with the electric power generation amount calculated as.

  Lt = C * {Id * d d (I, t) + Ib * (b (I, θ, t)}-C * {Id * I d (I) + Ib * b b (I, θ)} (Equation 13)

5 (a) and 5 (b) are graphs showing the amount of power generation of the solar cell 1 installed at a certain place in the Kinki region. The solar cell 1 has a total light receiving area of about 10 m ² and is installed at an inclination of about 20 ° in the south direction. Also, the conversion efficiency under standard conditions is about 20%. The incident angle loss amount Lθ, irradiance loss amount LI and temperature loss amount Lt for one day are calculated by accumulating the incident angle loss amount Lθ, irradiance loss amount LI and temperature loss amount Lt in one-minute units, respectively. It is calculated. In addition, the incident angle loss Lθ, the irradiance loss LI, and the temperature loss Lt for one year are respectively accumulated for the incident angle loss Lθ, the irradiance loss LI, and the temperature loss Lt for one day. Calculated by

  FIG. 5A shows an estimated power generation amount, incident angle loss amount, irradiance loss amount, temperature loss amount, and estimated maximum power generation amount for a given day. The estimated power generation amount is a value calculated using the second power generation amount estimation model. The estimated maximum power generation amount is a value obtained by adding the estimated power generation amount, the incident angle loss amount, the irradiance loss amount, and the temperature loss amount. That is, the amount of power that can be generated when the solar cell 1 is under standard conditions.

  The ratio of the incident angle loss to the estimated maximum power generation is about 0%, the ratio of the irradiance loss to the estimated maximum power generation is about 2%, and the ratio of the temperature loss to the estimated maximum power generation is about 5% is there. Therefore, it can be seen that the loss of the amount of power generation on this day is the largest factor of the driving temperature, next the largest factor of the irradiance, and the smallest factor of the incident angle.

  FIG. 5 (b) shows an estimated power generation amount, incident angle loss amount, irradiance loss amount, temperature loss amount, and estimated maximum power generation amount for a given year. The ratio of the incident angle loss to the estimated maximum power generation is about 0%, the ratio of the irradiance loss to the estimated maximum power generation is about 3%, and the ratio of the temperature loss to the estimated maximum power generation is about 4% is there. Looking at the yearly basis, the same trend is seen as the daily trend.

  In addition, comparison verification is performed between the actually measured power generation amount measured by the power conversion device 2 of the solar cell 1 by time and the estimated power generation amount by time estimated using the second power generation amount estimation model. The correlation coefficient between the two was 0.999 or more. This indicates that the three parameters of the incident angle, the irradiance and the driving temperature can almost explain various fluctuation factors in the real environment. That is, it is shown that the actual power generation amount can be estimated almost accurately from the total solar radiation amount and the driving temperature by using the second power generation amount estimation model.

  If the second power generation amount estimation model is used, it is possible to individually and quantitatively analyze how much the three parameters that cause fluctuation in the actual environment affect the loss of the power generation amount. In the following, we analyze three parameters that take into consideration the influence of weather factors and seasonal factors.

  FIGS. 6 (a) and 6 (b) are graphs showing the ratio of the weather in the installation place of the solar cell 1 in one year and the ratio of the estimated amount of power generation according to the weather in one year. In this graph, the weather is classified into four: clear, fine, semi-fine, and cloudy. In this example, the ratio of the cloud to the entire sky is classified as 0-20% clear, 20-40% clear, 40-70% semi-clear, and 70-100% cloudy.

  FIGS. 7 (a) to 7 (d) are graphs showing the estimated power generation amount, incident angle loss amount, irradiance loss amount, and temperature loss amount of the solar cell 1 in one year classified by weather. . Fig. 7 (a) shows the cumulative power generation and loss amount on a clear day, Fig. 7 (b) shows the cumulative power generation and loss amount on a fine day, and Fig. 7 (c) shows the cumulative power generation amount on the near fine day・ The amount of loss is shown in Fig. 7 (d). The balance of loss factors changes with the weather. For example, on clear, fine and semi-clear days, the main factor of the loss is the driving temperature, while on cloudy days, the main factor is the irradiance. Also, it is understood that the incident angle is the smallest as a loss factor regardless of the weather.

  FIG. 8 is a graph showing the ratio of the estimated amount of power generation by season in the year of the solar cell 1. In this example, March to May are classified as spring, June to August as summer, September to November as autumn, and December to February as winter.

  FIGS. 9 (a) to 9 (d) are graphs showing the estimated power generation amount, incident angle loss amount, irradiance loss amount, and temperature loss amount in one year of the solar cell 1 classified by season. . Fig. 9 (a) shows the accumulated power generation and loss in spring, Fig. 9 (b) shows the accumulated power and loss in summer, and Fig. 9 (c) shows the accumulated power and loss in autumn. d) shows the accumulated power generation and loss in winter, respectively. The balance of the loss factor changes with the weather. The overall trend is similar to that by weather, but it can be seen that in winter there is no loss due to temperature factors.

  As described above, according to the present embodiment, three main parameters (irradiance, incident angle, and temperature), which become the fluctuation factor of the real environment, are reflected on the basis of sunlight (the amount of total solar radiation). By using the power generation amount estimation model, it is possible to calculate the power generation amount extremely close to the measured power generation amount of the solar cell 1. In addition, the dependence of irradiance, incident angle, and temperature on the amount of power generation can be separated, and sophisticated factor analysis becomes possible. In this respect, these factors can not be separated from the voltage and current values after these factors are intertwined, and sophisticated factor analysis is difficult.

  Moreover, since factor analysis is possible for the loss amount of the solar cell 1, it is possible to grasp the strengths and weaknesses of the solar cell 1, and to highlight differences between product appeal points, improvement points, and other companies' products. it can. Also, by analyzing the irradiance, the incident angle and the loss due to the temperature according to the weather, it is possible to emboss what kind of weather the solar cell 1 is strong against and what kind of weather is weak. The same analysis can be performed by season.

  The present invention has been described above based on the embodiments. The embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

In the above-described embodiment, the illumination dependency coefficient E (I), the incident angle dependency coefficient E (θ), and the temperature dependency coefficient f (t) for correcting the conversion efficiency η ₀ under standard conditions are functions (fourth order Although an example of derivation using a function or a linear function is shown, it may be derived by referring to a table.

In the above embodiment, the conversion efficiency η ₀ under the standard conditions is corrected using three coefficients, the illuminance dependent coefficient E (I), the incident angle dependent coefficient E (θ) and the temperature dependent coefficient f (t). , And may be corrected using at least one of the three coefficients. For example, even if the estimated amount of power generation by using the conversion efficiency obtained by correcting the conversion efficiency eta ₀ under standard conditions using only illuminance dependence coefficient E (I), accept the conversion efficiency eta ₀ under standard conditions The estimation accuracy is improved compared to the case of estimating the power generation amount. Also, as can be understood from the above description, if the power generation amount is estimated using the conversion efficiency in which the conversion efficiency η ₀ under the standard conditions is corrected using the illuminance dependent coefficient E (I) and the temperature dependent coefficient f (t), It is possible to estimate the measured power generation with fairly high accuracy.

  The embodiment may be specified by the following items.

[Item 1]
A data acquisition unit (131) for acquiring measurement data of the amount of solar radiation incident on the solar cell (1);
A first dependency between the conversion efficiency of the solar cell (1) and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and the solar device derived in advance At least one of a second dependency between the conversion efficiency of the battery (1) and the incident angle of sunlight, and the second correction process of the conversion efficiency using the incident angle estimated based on the solar orbit A conversion efficiency correction unit (132),
A power generation amount estimation unit (135) configured to estimate a power generation amount of the solar cell (1) based on the acquired amount of solar radiation and the corrected conversion efficiency;
A power generation amount estimation device (10) of a solar cell (1), comprising:
According to this, it is possible to improve the estimation accuracy of the power generation amount by considering the first dependency and / or the second dependency.
[Item 2]
The data acquisition unit (131) further acquires measurement data of the temperature of the solar cell (1),
The conversion efficiency correction unit (132) includes the first correction process, the second correction process, and the conversion efficiency of the solar cell (1) and the temperature of the solar cell (1) derived in advance. 3. A power generation amount estimation device (10) of a solar cell (1) according to item 1, characterized by executing a third correction process of the conversion efficiency using the dependency and the acquired temperature.
According to this, it is possible to estimate a power generation amount substantially the same as the actually-measured power generation amount by considering the first dependency relationship, the second dependency relationship, and the third dependency relationship.
[Item 3]
The data acquisition unit (131) acquires measurement data of the total amount of solar radiation from the global actinometer,
This power generation amount estimation device (10)
The system further comprises a direct scattering separation unit (134) that separates the acquired total solar radiation amount into a scattered solar radiation amount and a direct solar radiation amount using a predetermined separation formula,
The conversion efficiency correction unit (132)
The conversion efficiency of the solar cell (1) against scattered solar radiation is corrected based on the first dependency and the separated scattered solar radiation, and the third dependency and the acquired solar cell (1) Correcting the conversion efficiency of the solar cell (1) to scattered solar radiation based on the temperature of
The conversion efficiency for direct solar radiation of the solar cell (1) is corrected based on the first dependency and the separated direct solar radiation, and the incident estimated based on the second dependency and the solar orbit The conversion efficiency for direct solar radiation of the solar cell (1) is corrected based on the angle, and the solar cell (1) is corrected based on the third dependency and the acquired temperature of the solar cell (1) Correct the conversion efficiency for direct solar radiation,
The power generation amount estimation unit (135) corrects the product of the separated scattered solar radiation amount and the conversion efficiency for the scattered solar radiation of the corrected solar cell (1), and the separated direct delivery solar radiation amount. The power generation amount of the solar cell (1) according to item 2, wherein the power generation amount of the solar cell (1) is estimated based on the product of the conversion efficiency of the solar cell (1) to direct sunlight Quantity estimation device (10).
According to this, it is possible to construct a sophisticated estimation model that corrects the conversion efficiency for each of the scattered solar radiation component and the direct solar radiation component.
[Item 4]
It further comprises a loss amount estimation unit (136) for estimating the amount of power generation of the solar cell (1), such as the amount of solar radiation, the incident angle or the amount of loss due to the temperature of the solar cell (1);
A process of estimating the amount of loss due to the amount of solar radiation based on the difference between the amounts of power generation when the first correction processing is performed and when the first correction processing is not performed; the second correction A process of estimating the amount of loss caused by the incident angle based on the difference between the amount of power generation when the process is performed and when the process is not performed, and a difference between the amount of power generation when the third correction process is performed and when it is not performed The power generation amount estimation apparatus of the solar cell (1) according to item 2 or 3, characterized in that at least one of the processes for estimating the amount of loss caused by the temperature of the solar cell (1) based on (10).
According to this, it is possible to carry out factor analysis on the loss of generated power.
[Item 5]
Obtaining measurement data of the amount of solar radiation incident on the solar cell;
A first dependency between the solar cell conversion efficiency and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and a conversion of the solar cell derived in advance Performing at least one correction of the second correction processing of the conversion efficiency using a second dependency between the efficiency and the incident angle of sunlight, and the incident angle estimated based on a solar orbit;
Estimating the power generation amount of the solar cell based on the acquired amount of solar radiation and the corrected conversion efficiency;
A method for estimating the amount of power generation of a solar cell, comprising:
According to this, it is possible to improve the estimation accuracy of the power generation amount by considering the first dependency and / or the second dependency.
[Item 6]
Obtaining measurement data of the amount of solar radiation incident on the solar cell;
A first dependency between the solar cell conversion efficiency and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and a conversion of the solar cell derived in advance Performing at least one correction of the second correction processing of the conversion efficiency using a second dependency between the efficiency and the incident angle of sunlight, and the incident angle estimated based on a solar orbit;
Estimating the power generation amount of the solar cell based on the acquired amount of solar radiation and the corrected conversion efficiency;
A program for causing a computer to execute a solar cell power generation amount estimation program.
According to this, it is possible to improve the estimation accuracy of the power generation amount by considering the first dependency and / or the second dependency.

  DESCRIPTION OF SYMBOLS 1 solar cell, 1a solar radiation sensor, 1b temperature sensor, 2 power conversion devices, 3 systems, 4 measurement data storage devices, 5 networks, 10 power generation amount estimation devices, 11 communication units, 12 media insertion units, 13 control units, 131 data Acquisition unit, 132 conversion efficiency correction unit, 133 incidence angle estimation unit, 134 direct dispersion separation unit, 135 power generation amount estimation unit, 136 loss amount estimation unit, 14 console unit, 15 storage unit.

  The present invention can be used to estimate the amount of power generation of a solar cell.

Claims (6)

A data acquisition unit that acquires measurement data of the amount of solar radiation incident on the solar cell;
A first dependency between the solar cell conversion efficiency and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and a conversion of the solar cell derived in advance A conversion efficiency correction unit that executes at least one of a second dependency between the efficiency and the incident angle of sunlight, and a second correction process of the conversion efficiency using the incident angle estimated based on the sun trajectory;
A power generation amount estimation unit configured to estimate a power generation amount of the solar cell based on the acquired solar radiation amount and the corrected conversion efficiency;
An apparatus for estimating the amount of power generation of a solar cell, comprising: The data acquisition unit further acquires measurement data of the temperature of the solar cell,
The conversion efficiency correction unit is configured to acquire the first correction processing, the second correction processing, and a third dependency between the conversion efficiency of the solar cell derived in advance and the temperature of the solar cell. The power generation amount estimation apparatus for a solar cell according to claim 1, wherein a third correction process of the conversion efficiency using a temperature is performed. The data acquisition unit acquires measurement data of total solar radiation from the global actinometer,
This power generation amount estimation device
The system further comprises a direct scattering separation unit that separates the acquired total solar radiation amount into a scattered solar radiation amount and a direct solar radiation amount using a predetermined separation formula,
The conversion efficiency correction unit
Based on the first dependency and the separated amount of scattered solar radiation, the conversion efficiency of the solar cell to scattered solar radiation is corrected, and based on the third dependency and the temperature of the obtained solar cell Correcting the conversion efficiency of the solar cell to scattered solar radiation,
The conversion efficiency for direct solar radiation of the solar cell is corrected based on the first dependency and the separated direct solar radiation, and the incident angle estimated based on the second dependency and the solar orbit is also calculated. And correcting the conversion efficiency of the solar cell to direct solar radiation, and correcting the conversion efficiency of the solar cell to direct solar radiation based on the third dependency and the acquired temperature of the solar cell,
The power generation amount estimation unit is a product of the separated scattered solar radiation amount and the converted conversion efficiency for the scattered solar radiation of the solar cell, and the separated direct solar radiation amount and the direct delivery of the corrected solar cell The power generation amount estimation device of a solar cell according to claim 2, wherein the power generation amount of the solar cell is estimated based on a product of conversion efficiency with respect to solar radiation. And a loss amount estimation unit configured to estimate a loss amount caused by a solar radiation amount, an incident angle, or a temperature of the solar cell, of the power generation amount of the solar cell.
The loss amount estimation unit estimates the amount of loss due to the amount of solar radiation based on the difference between the amounts of power generation when the first correction processing is performed and when the first correction processing is not performed, and executes the second correction processing. Processing for estimating the amount of loss due to the incident angle based on the difference between the amounts of power generation in the case and in the case of non-execution, and the difference in amount of power generation between the case where the third correction process is performed and 4. The apparatus according to claim 2, wherein at least one of the processes for estimating the amount of loss caused by the temperature of the solar cell is performed. Obtaining measurement data of the amount of solar radiation incident on the solar cell;
A first dependency between the solar cell conversion efficiency and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and a conversion of the solar cell derived in advance Performing at least one correction of the second correction processing of the conversion efficiency using a second dependency between the efficiency and the incident angle of sunlight, and the incident angle estimated based on a solar orbit;
Estimating the power generation amount of the solar cell based on the acquired amount of solar radiation and the corrected conversion efficiency;
A method for estimating the amount of power generation of a solar cell, comprising: Obtaining measurement data of the amount of solar radiation incident on the solar cell;
A first dependency between the solar cell conversion efficiency and the amount of solar radiation derived in advance, a first correction process of the conversion efficiency using the acquired amount of solar radiation, and a conversion of the solar cell derived in advance Performing at least one correction of the second correction processing of the conversion efficiency using a second dependency between the efficiency and the incident angle of sunlight, and the incident angle estimated based on a solar orbit;
Estimating the power generation amount of the solar cell based on the acquired amount of solar radiation and the corrected conversion efficiency;
A program for causing a computer to execute a solar cell power generation amount estimation program.

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