JPH07202234A - Method of simulating solar battery - Google Patents

Abstract

PURPOSE:To provide a method of simulating an arbitrary solar battery whereby when it is kept in a reference state its output current and voltage in this state can be computed simply. CONSTITUTION:When a previously selected standard solar battery is kept in a predetermined state, the characteristics are held (step 551). The curve factors present in the characteristics of the standard solar battery which is held in the step S51 are made to coincide with the curve factors present in the characteristic of the solar battery which is the object to be computed, and thereby, the maximum power operating point present in the characteristic of the standard solar battery is subjected to a conversion (step S52). Subsequently, based on the maximum power operating point converted in the step S52, the respective operating points present in the characteristic of the standard solar battery are subjected to conversions (step S53). Further, the respective parameters present in the characteristic of the standard solar battery are made to coincide with the respective parameters of the solar battery which is the object to be computed, and thereby, the respective operating points obtained in the step S53 are subjected to reconversions (step S54).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell simulation method for calculating an output current and an output voltage in a reference state of an arbitrary solar cell.

[0002]

2. Description of the Related Art In research and development of a solar cell, an output current with respect to an output voltage of the solar cell and generated electric power are used to evaluate the performance of the solar cell. For this purpose, the solar cell is kept in a predetermined state, for example, a reference state, and the solar cell data is collected. In the standard state, the solar radiation to the solar cell is 1000 [W / m ² ] and the temperature of the solar cell is 2
Keep at 5 [° C]. In such a state, the solar cell is measured.

[0003]

By the way, in order to keep the solar cell in the standard state, the solar radiation amount to the solar cell is always 1
It must be adjusted to 000 [W / m ² ]. Moreover, it is necessary to keep the temperature of the solar cell at 25 [° C.]. However, in the actual measurement, the amount of solar radiation and the temperature set in the standard state cannot always be kept constant, and they fluctuate somewhat. For this reason, an error occurs in the measured data, and the performance of the solar cell cannot be evaluated accurately.

The object of the present invention is to eliminate the above drawbacks and to provide a solar cell simulation method capable of easily calculating the output current and output voltage of a solar cell in this state when an arbitrary solar cell is kept in the reference state. To provide.

[0005]

According to a first aspect of the present invention, there is provided a first treatment process for retaining characteristics of a standard solar cell selected in advance in a predetermined state, and a standard treatment process for the first treatment process. A second processing step for converting the maximum output operating point in the characteristics of the standard solar cell by matching the fill factor in the characteristics of the solar cell with the curve factor of the solar cell to be calculated, and a second processing step The third processing step for converting each operating point in the characteristics of the standard solar cell on the basis of the maximum output operating point converted in A fourth processing step in which each operating point obtained in the third processing step is reconverted by matching the parameters.

Further, the invention of claim 1 includes a processing step of drawing a current-voltage characteristic curve by using the operating point obtained in the fourth processing step. Further, it includes a processing step of calculating the electric power output from the solar cell to be calculated in the reference state using the operating point obtained in the fourth processing step and drawing a power-voltage characteristic curve by the calculated electric power.

According to the invention of claim 4, the characteristics when the standard solar cell selected in advance is kept in a predetermined state are as follows:
Output current against output voltage, short circuit current I _SC , open circuit voltage V
_When the first processing step that holds _OC , the maximum output operating current I _OP , the maximum output operating voltage V _OP , and the fill factor FF and the characteristics of the solar cell to be calculated are input, the fill factor FF _{1 of} this solar cell is input. In order to match the fill factor FF with the second processing step of calculating the maximum output operating current I _OP1 and the maximum output operating voltage V _OP1 , the characteristics held in the first processing step and the second processing step.
When the output voltage is lower than the maximum output operating voltage V _OP , the output current I _A and the output voltage V _A of the standard solar cell in a predetermined state are calculated by using I _A1 = (I _OP1 V _A I _A −I _OP V _A I _A + I _OP V _OP I _A ) / I
_OP V _OP V _A1 = (V _A V _OP1 I _OP1 ) / (I _OP1 V _A −I _OP V _A + I _OP
V _OP ) is used to convert the output current I _A1 and the output voltage V _A1 ,
When it is higher than the maximum output operating voltage V _OP, the output current I _B and the output voltage V _B of the standard solar cell in a predetermined state are _{expressed as} I _B1 = (V _OP1 I _OP1 I _B ) / (V _OP1 I _B −V _OP I _B + V _OP
I _OP ) V _B1 = (V _OP1 I _B V _B −V _OP I _B V _B + V _OP I _OP V _B ) /
Using the formula (V _OP I _OP ), the third process step of converting the output current I _B1 and the output voltage V _B1 and the characteristic held in the first process step are
In order to match the short-circuit current I _SC1 , open-circuit voltage V _OC1 , maximum output current I _OP2 , and maximum output voltage V _OP2 of the characteristics of the solar cell to be calculated, which are input in the processing process, the output voltage is the maximum output operating voltage. Output current I _A1 when lower than V _OP1
And the output voltage V _A1 , I _A2 = (I _SC1 / I _SC ) × I _A1 V _A2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (I _SC /
I _SC1 ) × V _A1 is used to convert into an output current I _A2 and an output voltage V _A2 ,
When the output current I _B1 and the output voltage V _B1 are higher than the maximum output operating voltage V _OP1 , I _B2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (V _OC /
V _OC1 ) × I _B1 V _B2 = (V _OC1 / V _OC ) × V _B1 is used to include an output current I _B2 and a fourth processing step of converting into an output voltage V _B2 .

Further, the invention of claim 4 includes a processing step of drawing a current-voltage characteristic curve by using the output current and the output voltage obtained in the fourth processing step. Further, the output current and the output voltage obtained in the fourth processing step are used to calculate the electric power output by the solar cell to be calculated in the reference state, and the electric power-voltage characteristic curve is calculated based on the calculated electric power and the output voltage. Including the process of drawing.

[0009]

According to the first aspect of the invention, as shown in FIG. 1, the characteristics when the standard solar cell selected in advance is kept in a predetermined state are held (step S51). By matching the fill factor of the standard solar cell with the fill factor of the calculation target solar cell, the maximum output operating point of the standard solar cell is converted (step S52). Each operating point of the standard solar cell is converted by the converted maximum output operating point (step S5).
3). Further, each operating point of the standard solar cell is converted again by matching each parameter in the characteristics of the standard solar cell with each parameter of the calculation target solar cell (step S54).

As a result, it is possible to obtain each operating point of the solar cell to be calculated when the solar cell is installed in the standard state.

According to the invention of claim 4, the fill factor FF of the standard solar cell is matched with FF ₁ of the solar cell to be calculated,
Maximum output operating current I _{OP at} maximum output operating point of standard solar cell
And the maximum output operating voltage V _OP , the maximum output operating current I _OP1
And the maximum output operating voltage V _OP1 .

Thereafter, the converted maximum output operating current I _OP1
And the maximum output operating voltage V _OP1 convert each operating point of the standard solar cell. At this time, when the output voltage to be converted is smaller than the maximum output operating voltage V _OP , the output current I _A and the output voltage V _A at each operating point of the standard solar cell are _{expressed as} I _A1 = (I _OP1 V _A I _A −I _{OP V A I A + I OP} V OP I A) / I
_OP V _OP V _A1 = (V _A V _OP1 I _OP1 ) / (I _OP1 V _A −I _OP V _A + I _OP
V _OP ) is used for conversion. The output voltage is the maximum output operating voltage V
_{When it is} larger than _OP , the output current I _A and the output voltage V _A at each operating point of the standard solar cell are I _B1 = (V _OP1 I _OP1 I _B ) / (V _OP1 I _B −V _OP I _B + V _OP
I _OP ) V _B1 = (V _OP1 I _B V _B −V _OP I _B V _B + V _OP I _OP V _B ) /
Conversion is performed using the formula of (V _OP I _OP ). Thereby, the output current and the output voltage of the standard solar cell are converted based on the fill factor.

Next, the short circuit current I _SC of the standard solar cell, the open circuit voltage V _OC , the maximum output operating current I _OP , and the maximum output operating voltage V
_In order to match _OP with the short-circuit current I _SC1 , open-circuit voltage V _OC1 , maximum output current I _OP2 , and maximum output voltage V _OP2 of the solar cell to be calculated, the converted output current and output voltage of the standard solar cell are re-adjusted. Convert. At this time, when the output voltage to be converted is smaller than the maximum output operating voltage V _OP1 , I _A2 = (I _SC1 / I _SC ) × I _A1 V _A2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (I _SC /
I _SC1 ) × V _A1 is used for conversion. When the output voltage is higher than the maximum output operating voltage V _OP1 , I _B2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (V _OC /
The conversion is performed using the formula of V _OC1 ) × I _B1 V _B2 = (V _OC1 / V _OC ) × V _B1 .

As a result, it is possible to obtain each operating point of the calculation target solar cell when installed in the reference state.

According to the second, third, fifth and sixth aspects of the present invention, it is possible to obtain the current-voltage characteristic and the power-voltage characteristic when the calculation target solar cell is installed in the reference state.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 5 is a block diagram showing an example of an arithmetic system for carrying out the present invention. In this computing system, a solar battery module including a plurality of solar battery cells is used as a solar battery for simulation.

The calculation system includes an input device 1 for inputting information on a solar cell, an external storage device 2 for magnetically storing information, a control device 3, and a display device 4 for displaying processed information. And an output device 5 for printing out the processed information.

In the computing system, the preselected solar cells are standard solar cells. And 1000 [W
/ M ² ], and a module temperature of 25 [° C.], that is, a standard state where a standard solar cell is installed in a state where the module temperature is maintained, that is, a standard state, is input from the input device 1.

At this time, the input characteristic is each operating point of the standard solar cell, that is, the output current with respect to each output voltage of the standard solar cell. When the output current and the output voltage of the standard solar cell are input, the control device 3 stores the output current and the output voltage in the external storage device 2 as shown in the flowcharts of FIGS. 2 to 4 (step S1). . After that, the parameters of the standard solar cell are as follows: short circuit current I _SC of standard solar cell, open circuit voltage V _OC , optimum current (maximum output operating current) I _OP , optimum voltage (maximum output operating voltage) V _OP and The fill factor FF is input to the input device 1. The control device 3 stores these parameters in the external storage device 2 (step S2).

Here, the fill factor FF in the parameters
Is called a fill factor and is represented by the formula: FF = (I _OP V _OP ) / (I _SC V _OC ) (1). The current-voltage characteristic of such a standard solar cell is shown by the curve 101 in FIG. As represented by the curve 101, the optimum operating point P (V _OP that can obtain the maximum output is obtained from the short-circuit current I _{SC on the} vertical axis indicating the current to the open circuit voltage V _OC on the horizontal axis indicating the voltage. , I _OP ) exists.

After step S2, the short-circuit current I _SC1 , open-circuit voltage V _OC1 , optimum current I _OP1 , are set as parameters of the solar cell to be simulated, that is, the solar cell to be calculated.
The optimum voltage V _OP1 and fill factor FF ₁ are input to the input device 1. The control device 3 stores these parameters (step S3).

After step S3, the control device 3 determines the fill factor FF of the standard solar cell as FF ₁ of the solar cell to be calculated.
Then, the optimum current I _OP1 and the optimum voltage V _OP1 of the optimum operating point P ₁ of the calculation target solar cell are calculated (step S4). At this time, the control device 3, as shown in FIG. 6, is a point Q (V _OC , I _SC ) at which the short circuit current I _SC of the standard solar cell and the open circuit voltage V _OC intersect, and the optimum operating point of the standard solar cell. It is assumed that the optimum operating point P ₁ of the calculation target solar cell exists on the straight line 102 connecting P (V _OP , I _OP ). Then, the optimum operating point P of the standard solar cell is converted so that the fill factor FF of the standard solar cell becomes equal to the fill factor FF ₁ of the calculation target solar cell.

Thereafter, the control device 3 uses the optimum current I _OP1 and the optimum voltage V _OP1 calculated in step S4,
The output current and output voltage of the standard solar cell stored in step S1 are converted. At this time, it is checked whether or not the converted output voltage of the standard solar cell is smaller than the optimum voltage V _OP (step S5). For the output voltage smaller than the optimum voltage V _OP , each operating point A of the standard solar cell is as follows.
To convert. When the output current at the operating point A at this time is I _A and the output voltage is V _A , the output current I _A is I _A1 = (I _OP1 V _A I _A −I _OP V _A I _A + I _OP V _OP I _A ) / I _OP V _OP (2) is used to convert to output current I _A1 (step S
6).

Thereafter, the output voltage V _A is calculated by the following formula: V _A1 = (V _A V _OP1 I _OP1 ) / (I _OP1 V _A −I _OP V _A + I _OP V _OP ) (3) Convert to V _A1 (step S
7). In the expressions (2) and (3), the output current I _A1 and the output voltage V _A1 are calculated on the basis of the ratio of the current to the power, and as shown in FIG. A
₁ (V _A1 , I _A1 ) is calculated.

After step S7, the control device 3 checks whether the output voltage is higher than the optimum voltage V _OP of the standard solar cell (step S8). For an output voltage larger than the optimum voltage V _OP , each operating point B of the standard solar cell is converted as follows. The output current at the operating point B at this time is I _B
And the output voltage is V _B , the output current I _B is calculated by the following formula: I _B1 = (V _OP1 I _OP1 I _B ) / (V _OP1 I _B −V _OP I _B + V _OP I _OP ) (4) The output current I _B1 (step S
9). After this, the output voltage V _B, with V _B1 = formula _{(V OP1 I B V B -V} OP I B V B + V OP I OP V B) / (V OP I OP) (5), Convert to output voltage V _B1 (step S1
0). In the expressions (4) and (5), the output current I _B1 and the output voltage V _B1 are calculated with reference to the ratio of the voltage and the electric power, and FIG.
As shown in, each operating point B ₁ (V
_B1 , I _B1 ) is calculated.

In this way, the fill factor FF is matched with FF _1, and the operating point of the standard solar cell is converted into the operating point to be calculated. When the operating points obtained by this conversion are connected, a curve 103 shown in FIG. 6 is obtained.

When this conversion is completed, the control device 3 uses the short-circuit current, open-circuit voltage, optimum current, and optimum voltage of the standard solar cell and the solar cell to be calculated, which are stored in step S2, to operate point A ₁ , Reconvert B ₁ .

In this conversion, the control device 3 checks whether or not each voltage at the operating point to be converted is smaller than the optimum voltage V _OP1 (step S11). Optimum voltage V
_When it is smaller than _OP1, the output current I _A1 at the operating point A ₁ is converted into the output current I _A2 by using I _A2 = (I _SC1 / I _SC ) × I _A1 (6) (step S1
2). Thereafter, the output voltage V _A1, using a _{V A2 = {(V OP2 I} OP2) / (V OP1 I OP1)} × (I SC / I SC1) × V A1 (7), the output voltage V _A2 Convert. (Step S1
3). By these conversions, as shown in FIG. 7, the operating point A ₁ (V _A1 , I _A1 ) is converted into the operating point A ₂ (V _A2 , I _A2 ).

Then, it is checked whether the calculated voltage is higher than the optimum voltage V _OP1 (step S14). When it is larger than the optimum voltage V _OP1 , the output current I _B1 at the operating point B ₁ is _expressed as I _B2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (V _OC / V _OC1 ) × I _B1 (8 ) _Is used to convert the output current I _B2 (step S1).
5). Thereafter, the output voltage V _B1 at the operating point B ₁ is converted into the output voltage V _B2 by using the formula V _B2 = (V _OC1 / V _OC ) × V _B1 (9) (step S1
6). By these conversions, the operating point B ₁ (V _B1 , I _B1 ) is converted to the operating point B ₂ (V _B2 , I _B2 ) as shown in FIG. 7.

As described above, the short-circuit current I _SC , open-circuit voltage V _OC , maximum output operating current I _OP and maximum output operating voltage V _OP of the standard solar cell are _converted into the short-circuit current I of the solar cell to be calculated.
The operating point of the solar cell calculated previously is reconverted to match _SC1 , open circuit voltage V _OC1 , maximum output current I _OP2 and maximum output voltage V _OP2 . This makes it possible to obtain the output current and output voltage of the solar cell to be calculated when the reference state is set.

The control device 3 displays the calculation result on the display device 4 and outputs it to the output device 5. After this, when the current-voltage characteristic curve of the solar cell to be calculated is required,
The control device 3 draws a characteristic curve from the calculated output current and output voltage. That is, a current-voltage characteristic curve as shown by the curve 104 in FIG. 7 is drawn by connecting the respective operating points obtained by the reconversion. Then, this characteristic curve is displayed on the display device 4.
And output to the output device 5.

Further, when the power-voltage characteristic curve of the solar cell to be calculated is required, the controller 3 calculates the power from the calculated output current and output voltage. Then, a power-voltage characteristic curve is obtained from the power and the output voltage, displayed on the display device 4, and output to the output device 5.

[0034]

As described above, according to the inventions of claims 1 and 4, when the characteristics of the standard solar cell in a predetermined state, for example, the characteristics in the reference state are given in advance, the sun to be operated is calculated. By simply inputting the characteristics of the battery, it is possible to easily calculate the operating point when the solar cell to be calculated is in the reference state.

Further, according to the inventions of claims 2, 3, 5, and 6, using the calculated operating point,
A current-voltage characteristic curve and a power-voltage characteristic curve in the standard state can be drawn.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the present invention.

FIG. 2 is a flowchart showing control of the control device.

FIG. 3 is a flowchart showing control of the control device.

FIG. 4 is a flowchart showing control of the control device.

FIG. 5 is a block diagram showing an example of an arithmetic system for carrying out the present invention.

FIG. 6 is a diagram showing how the characteristics of a solar cell are converted.

FIG. 7 is a diagram showing how the characteristics of a solar cell are converted.

[Explanation of symbols]

 Step S51 to Step S54 Process

Claims (6)

[Claims] 1. A first treatment step for retaining characteristics of a preselected standard solar cell when kept in a predetermined state, and a fill factor in the characteristics of the standard solar cell retained in the first treatment step, Based on the second processing step of converting the maximum output operating point in the characteristics of the standard solar cell by matching the curvilinear factor of the calculation target solar cell, and the maximum output operating point converted in the second processing step, The third processing step of converting each operating point in the characteristics of the standard solar cell and the third parameter by matching each parameter in the characteristics of the standard solar cell with each parameter of the solar cell to be calculated
And a fourth processing step of reconverting each operating point obtained in the processing step. 2. The method for simulating a solar cell according to claim 1, further comprising a processing step of drawing a current-voltage characteristic curve using the operating point obtained in the fourth processing step. 3. A process of calculating the electric power output from the solar cell to be calculated in the reference state using the operating point obtained in the fourth process and drawing a power-voltage characteristic curve by the calculated power. The method for simulating a solar cell according to claim 1, further comprising: 4. The characteristics when the preselected standard solar cell is kept in a predetermined state are as follows: output current with respect to output voltage, short circuit current I _SC , open circuit voltage V _OC , maximum output operating current I _OP , maximum output operating voltage. When the first processing step for holding V _OP and fill factor FF and the characteristics of the solar cell to be calculated are input, the maximum output operation is performed in order to match the fill factor FF with the fill factor FF ₁ of this solar cell. Current I _OP1 and maximum output operating voltage V
_When the output voltage is lower than the maximum output operating voltage V _OP by using the second processing step of calculating _OP1 , the characteristic held in the first processing step and the calculation result calculated in the second processing step, Output current I of standard solar cell
_A and the output voltage V _A , I _A1 = (I _OP1 V _A I _A −I _OP V _A I _A + I _OP V _OP I _A ) / I
_OP V _OP V _A1 = (V _A V _OP1 I _OP1 ) / (I _OP1 V _A −I _OP V _A + I _OP
V _OP ) is used to convert the output current I _A1 and the output voltage V _A1 ,
When it is higher than the maximum output operating voltage V _OP, the output current I _B and the output voltage V _B of the standard solar cell in a predetermined state are _{expressed as} I _B1 = (V _OP1 I _OP1 I _B ) / (V _OP1 I _B −V _OP I _B + V _OP
I _OP ) V _B1 = (V _OP1 I _B V _B −V _OP I _B V _B + V _OP I _OP V _B ) /
Using the equation (V _OP I _OP ), the third processing step of converting the output current I _B1 and the output voltage V _B1 and the characteristic held in the first processing step are input in the second processing step, Short circuit current I _SC1 , open circuit voltage V _OC1 , maximum output current I _OP2 and maximum output voltage V of the characteristics of the target solar cell
_In order to match _OP2 , when the output voltage is lower than the maximum output operating voltage V _OP1 , the output current I _A1 and the output voltage V _A1 are _expressed as I _A2 = (I _SC1 / I _SC ) × I _A1 V _A2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (I _SC /
I _SC1 ) × V _A1 is used to convert into an output current I _A2 and an output voltage V _A2 ,
When the output current I _B1 and the output voltage V _B1 are higher than the maximum output operating voltage V _OP1 , I _B2 = {(V _OP2 I _OP2 ) / (V _OP1 I _OP1 )} × (V _OC /
A method of simulating a solar cell, which includes a fourth processing step of converting an output current I _B2 and an output voltage V _B2 by using an equation of V _OC1 ) × I _B1 V _B2 = (V _OC1 / V _OC ) × V _B1 . 5. The method for simulating a solar cell according to claim 4, further comprising the step of drawing a current-voltage characteristic curve using the output current and output voltage obtained in the fourth processing step. 6. The output current and the output voltage obtained in the fourth processing step are used to calculate the electric power output from the solar cell to be calculated in the reference state, and the calculated electric power and the output voltage are used to calculate the electric power. The method for simulating a solar cell according to claim 4, further comprising a step of drawing a voltage characteristic curve.