JP2014075216A - Solar simulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar simulator using LED light sources capable of maintaining pseudo sunlight of the solar simulator in a state similar to the state of sunlight and conducting accurate performance inspection for a solar cell.SOLUTION: A solar simulator comprises: a light source 10 where a number of LEDs for emitting intrinsic wavelengths for irradiating a solar cell 1 with pseudo sunlight are combined and arranged; an integrator for totally reflecting light made incident from the light source 10 a plurality of times in the inside thereof and emitting the light toward a side of the solar cell; a monitoring part 100 which includes an illuminance monitor 110 for measuring illuminance of the pseudo sunlight made incident toward the side of the solar cell 1: a characteristic analysis part 200 for analyzing the illuminance of the pseudo sunlight which is measured through the monitoring part 100; and a controller 300 for transmitting a feedback signal to the side of the light source 10 in accordance with an analysis result of the characteristic analysis part 200.

Description

  The present invention relates to a solar simulator provided with a feedback mechanism that uses an LED light source in a solar simulator and can adjust a spectrum to approximate sunlight.

  A solar cell is known as a method of using solar energy. And when manufacturing a solar cell, the measurement of an output characteristic is normally performed for the performance evaluation whether a solar cell has the target electric power generation capability. The output characteristics are photoelectric conversion characteristics obtained by measuring the current-voltage output characteristics (hereinafter abbreviated as IV characteristics) of the solar cell under light irradiation. As the light source, sunlight is desirable, but a solar simulator is used because the light intensity changes depending on the weather. The solar simulator uses a xenon lamp or a metal halide lamp instead of sunlight.

  On the other hand, a technique using an integrator for synthesizing these lights while using a xenon lamp instead of sunlight in a solar simulator has been proposed (Patent Document 1). However, in the above-mentioned Patent Document 1, a xenon lamp that approximates actual sunlight is used. However, when the lamp is lit for a long time, the amount of light changes due to a temperature rise, and eventually the simulated sunlight differs from actual sunlight. The output characteristics of the solar cell will be judged.

JP 2011-222655 A

This invention is made | formed in view of such a situation, The 1st objective is using the sunlight which approximated sunlight by using the light source which combined LED of various wavelengths, and the sun. To provide a solar simulator that can measure the output characteristics of a battery.
Moreover, the 2nd objective of this invention is providing the solar simulator which eliminated the light quantity shortage of the LED light source by arrange | positioning the said LED in multiple numbers by the array form.

  In order to achieve such an object, the solar simulator according to the first aspect of the present invention includes a light source unit in which a plurality of LEDs emitting a specific wavelength are arranged in combination to irradiate a solar cell with simulated sunlight, and an incident from the light source unit. A monitoring unit provided with an illuminance monitor that measures the illuminance of pseudo-sunlight incident on the solar cell side, an integrator that totally reflects light that is internally reflected a plurality of times and emits the light to the solar cell side, and the monitoring unit And a control unit for transmitting a feedback signal to the light source unit according to the analysis result of the characteristic analysis unit.

According to the first aspect of the invention, the pseudo sunlight generated by the LED light source used for inspecting the performance of the solar cell is maintained in the vicinity of the spectrum of sunlight, so that the accuracy and efficiency of the performance inspection for the solar simulator is increased. To do. Even if the number of LEDs is increased in order to increase the amount of light, spectrum unevenness can be eliminated by efficient light collection by the integrator.
In addition, the present invention can eliminate the spectrum unevenness that appears when the light source space is increased by disposing an integrator between the LED light source and the solar cell of the object to be measured. And since the present invention employs feedback control that changes the spectrum of the LED light source when monitoring the pseudo-sunlight irradiated on the measured object side and a difference from the spectrum of sunlight occurs, The inspection performance of the simulator can be improved.

  The solar simulator of the second invention is characterized in that, in the first invention, the characteristic analysis unit further comprises an IV analysis unit for analyzing an IV characteristic output from the solar cell.

  According to the 2nd invention, the output characteristic of the said solar cell can be measured more correctly by IV analysis with the solar simulator which uses a LED light source.

  A solar simulator of a third invention is the solar simulator according to the second invention, wherein the characteristic analysis unit includes an illuminance analysis unit that analyzes the illuminance characteristic, and from the illuminance characteristic of the simulated sunlight analyzed by the illuminance analysis unit, It is characterized by analyzing IV characteristics output from the solar cell while the illuminance of light is kept constant.

  According to the third invention, the IV characteristics of the solar cell can be accurately measured while the illuminance of the incident light is maintained constant.

  A solar simulator of a fourth invention is characterized in that, in the first invention, the monitoring unit further comprises a spectroscope capable of measuring a spectrum of pseudo-sunlight incident on the solar cell side.

  According to the fourth invention, it is possible to confirm in real time how much the simulated sunlight approximates to sunlight, so that the IV characteristics of the solar cell are measured by irradiating the simulated sunlight closer to sunlight. be able to.

  According to a fifth aspect of the solar simulator of the present invention, in the fourth aspect, the characteristic analysis unit includes a spectrum analysis unit that compares a spectrum of pseudo-sunlight measured by the spectrometer with a spectrum of sunlight. It is characterized by being transmitted to the control unit.

  According to the fifth aspect of the present invention, the matter related to how close the simulated sunlight is irradiated to the actual sunlight can be fed back to the control unit. Thereby, the said control part can grasp | ascertain the state with respect to the pseudo sunlight currently irradiated. Therefore, it is possible to reliably control each part by the control part thereafter.

  A solar simulator according to a sixth aspect of the present invention is the solar simulator according to the fifth aspect, further comprising an illuminance variable device that controls the emitted illuminance of each LED of the light source unit, wherein the control unit is configured to detect a spectral distribution difference between the simulated sunlight and the sunlight. When it is determined that there is, the control signal for increasing or decreasing the illuminance of each LED by the feedback signal is transmitted to the illuminance variable device.

  According to the sixth aspect of the present invention, when the difference in spectrum between simulated sunlight and sunlight occurs, the illuminance variable device can be controlled by the control unit, so that the IV characteristics of the solar cell can be measured more accurately. It can be done in a (or constant) environment.

  A solar simulator of a seventh invention is characterized in that, in the first invention, the LEDs of the light source unit are combined and arranged in an array at a predetermined interval around the integrator.

  According to the seventh invention, the LEDs emitting pseudo-sunlight are arranged at a predetermined interval around the integrator, so that the space occupied by the LEDs can be reduced and the light collection efficiency by the integrator can be improved. it can.

  The solar simulator of an eighth invention is characterized in that, in the first invention, the integrator is composed of a collection of square or polygonal micro integrators.

  According to the eighth aspect of the present invention, the integrator for condensing the light emitted from the LED can have various shapes, and the idea of the present invention can be applied to various embodiments.

It is a block diagram which shows schematically the solar simulator of this invention. 1 is a diagram illustrating a schematic configuration of a solar simulator according to a first embodiment of the present invention. It is the graph which compared the wavelength of the pseudo-sunlight at the time of combining LED of various wavelengths, and the wavelength of sunlight. It is a graph which shows the light intensity of the pseudo sunlight measured through an illumination intensity monitor. The analysis result of a spectrum is a graph which shows an example in case pseudo sunlight approximates sunlight. The analysis result of a spectrum is a graph which shows an example in case pseudo sunlight has a difference with sunlight. It is drawing which shows schematic structure of the solar simulator which concerns on 2nd Example of this invention. It is drawing which shows schematic structure of the solar simulator which concerns on 3rd Example of this invention.

FIG. 1 is a block diagram schematically showing a solar simulator of the present invention.
The solar simulator of the present invention includes a light source unit 10 that emits simulated sunlight, a monitoring unit 100 that monitors the characteristics of simulated sunlight irradiated on the solar cell of the DUT 1, and analyzes the illuminance or spectral characteristics of the simulated sunlight. A characteristic analysis unit 200, a control unit 300 that determines whether or not to control the illuminance of each LED of the light source unit 10 according to an analysis result of the characteristic analysis unit 200, and each of the control unit 300 that is transmitted as a feedback signal And an illuminance variable device 400 that varies the illuminance of each LED in accordance with a control signal for each LED.

  The light source unit 10 has a structure in which LEDs that emit respective wavelengths are combined. If necessary, the light source unit 10 can be configured by combining 20 to 30 LEDs that each emit a specific wavelength. Note that the scope of rights of the present invention is not limited to the number of LEDs. Since the LEDs that emit the respective unique wavelengths have an array structure, even if a large number of LEDs are combined, spectral unevenness does not occur.

  The monitoring unit 100 is disposed on one side or both sides (left and right or up and down direction) of the device under test 1 and measures the illuminance of pseudo-sunlight emitted from the light source unit 10 and incident on the device under test 1. An illuminance monitor 110 is provided. The illuminance monitor 110 measures the illuminance according to time so that the IV characteristic which is the output characteristic of the solar cell can be grasped at the optimum time. The monitoring unit 100 may include a spectroscope 120 such as a prism that can measure the light intensity of each wavelength with respect to the pseudo-sunlight incident on the measured object side.

The characteristic analysis unit 200 analyzes the illuminance characteristic and the spectral characteristic of the simulated sunlight measured through the monitoring unit 100 and transmits the result to the control unit 300.
The characteristic analyzer 200 includes an IV analyzer 210 that analyzes the IV characteristics output from the solar cell of the device under test 1 and an illuminance analyzer that analyzes the illuminance of the simulated sunlight measured by the illuminance monitor 110. 220 is included.
That is, the IV analysis unit 210 analyzes the IV output characteristic of the solar cell at the optimal timing from the illuminance characteristic of the pseudo-sunlight analyzed by the illuminance analysis unit 220. For example, the output characteristics of the solar cell in a section where light is emitted from each LED constituting the light source unit and the illuminance value is kept constant are analyzed.
In addition, the characteristic analysis unit 200 may further include a spectrum analysis unit 230 that performs spectrum analysis of simulated sunlight and actual sunlight. The spectrum analysis unit 230 compares the spectrum of simulated sunlight and sunlight from the light intensity of each wavelength measured through the spectrometer 120, and if an error occurs, transmits the error to the control unit 300.

  The controller 300 analyzes the characteristic detected by the characteristic analyzer 200 and outputs a control signal for changing the illuminance of light emitted from each LED of the light source unit 10 according to the result. 400. That is, as a result of analyzing the illuminance of simulated sunlight, the control unit 300 adjusts the illuminance of the corresponding LED through the illuminance variable device 400 when it is necessary to adjust the illuminance of the specific LED. For example, the illuminance of a specific LED can be increased or decreased to adjust the simulated sunlight to approximate actual sunlight.

  The spectrum changing device 400 adjusts the illuminance emitted from each LED according to a control signal transmitted from the controller 300. After analyzing the illuminance or spectrum of the simulated sunlight, a feedback circuit is provided for adjusting the illuminance of each LED of the light source unit 10 so that the conditions are close to those of actual sunlight.

Hereinafter, the configuration of the solar simulator according to the first embodiment of the present invention will be described with reference to FIGS.
FIG. 2 is a diagram showing a schematic configuration of the solar simulator according to the first embodiment of the present invention, and FIG. 3 shows the wavelength of pseudo sunlight and the wavelength of actual sunlight when LEDs of various wavelengths are combined. It is the graph compared.
In the light source unit 10 that emits simulated sunlight, a plurality of LEDs are combined and arranged in an array around the integrator 30. The integrator 30 totally reflects the incident light a plurality of times inside so that the emitted light has a uniform light distribution with respect to the object to be measured.
Each LED arranged in an array emits a specific wavelength. For example, an LED 11 that emits a short wavelength such as 405 nm, an LED 12 that emits a wavelength of 810 nm, and an LED 13 that emits a long wavelength such as 1200 nm are arranged in an array while maintaining a certain distance around the integrator 30. Yes. Here, when a plurality of LEDs are arranged in a line, the area of the space occupied by the LEDs increases, and spectrum unevenness may occur. In the present invention, the LEDs are arranged at a predetermined interval with the integrator 30 as the center. Are arranged in an array, such a problem can be solved. And LED condensing lens 21,22,23 is further arrange | positioned at each LED, and the condensing efficiency toward the integrator 30 of the light discharge | released from each LED increases by this.

As shown in FIG. 3, a spectral distribution that approximates sunlight can be realized by combining LEDs that emit light of each wavelength. FIG. 3 is a graph comparing the spectrum of sunlight with a combination of LEDs of various wavelengths.
In FIG. 3, the upper graph shows the distribution of various wavelengths emitted from the LED, and the lower graph shows a comparison of the spectrum distribution of sunlight with a combination of various wavelengths. For example, a spectrum graph of LED 11 emitting a wavelength of 405 nm, a spectrum graph of LED 12 emitting a wavelength of 810 nm, and a spectrum graph of LED 13 emitting a wavelength of 1200 nm are shown. Although not shown, LEDs that emit various wavelengths between 405 nm and 810 nm and LEDs that emit various wavelengths of 810 nm and 1200 nm are further arranged.

On the other hand, the integrator 30 is arranged between the DUT 1 and the LED array in order to eliminate spectral unevenness that can be generated by a large number of LEDs and to increase the illuminance and uniformity of light. The distance to the DUT 1 can be approximately 4 to 6 m. The integrator 30 is composed of an assembly of micro integrators having a square cross section, and can be composed of, for example, an assembly of 3 × 3 = 9 micro square integrators of 5 mm square. In order to make the outer shape of the aggregate as close as possible to the circumscribed circle, it is preferable that the cross section of each micro-integrator be configured by a polygon other than a square, for example, a regular hexagon.
Further, a secondary condenser lens 40 is provided on the entire surface of the integrator in order to increase the light collection efficiency when receiving the light emitted from each LED. The LED condensing lenses 21, 22, 23 and the secondary condensing lens 40 are not necessarily used at the same time, but only one or both of them may be used depending on the embodiment.

  On the other hand, the light that has passed through the integrator 30 enters the device under test 1 and the solar cell of the device under test generates power. A monitoring unit 100 for monitoring light incident on the device under test is disposed on one side of the device under test 1. The monitoring unit 100 is an illuminance monitor, and the spectrometer 120 can be installed together. The illuminance monitor 110 can be arranged on one side or both sides of the DUT 1. The illuminance monitor 110 receives light incident on the DUT 1 and measures the illuminance of the simulated sunlight.

FIG. 4 is a graph showing the light intensity (illuminance) of simulated sunlight measured through the illuminance monitor. The light intensity with time when, for example, 30 LEDs constituting the light source unit 10 are arranged in combination is shown. Show.
If light is emitted sequentially from the LED 1 to the LED 30, the light intensity is measured stepwise as shown in the figure. For example, when the LED 1 is turned on, the light intensity appears as an output 1, and when all the LEDs 30 are turned on, the light intensity increases up to the output 30. Through such a graph, the light intensity characteristics for each LED can be observed, and such light intensity characteristics for each LED can be confirmed and analyzed through the illuminance monitor 110 and the illuminance analyzer 220.
Further, the output characteristics of the solar cell of the object to be measured are preferably detected when the light intensity characteristic of the LED maintains a constant value. As shown in the figure, the entire light intensity is constant after all the LEDs 30 are turned on. The IV characteristic is measured for the interval in which the value is maintained.
And the said control part 300 performs the whole control for measuring the IV characteristic output from the solar cell of a to-be-measured object.

  On the other hand, the IV analysis unit 210 monitors how close the simulated sunlight emitted from the light source unit 10 is to sunlight.

FIG. 5 shows the relationship between the wavelength and the light intensity when simulated sunlight approximates sunlight. However, if some of the LEDs in the light source section do not have a desirable illuminance, a difference will occur in the spectrum analysis. FIG. 6 shows a case where pseudo-sunlight is different from sunlight as a result of analyzing the spectrum.
For example, as a result of analyzing the spectrum of pseudo-sunlight, 6A occurs when the light intensity is higher than the actual sunlight and 6B when the light intensity is weaker than the actual sunlight in a predetermined section as shown in FIG. At this time, the control unit 300 classifies the LEDs having wavelengths different from the actual sunlight and adjusts the light intensity of the LEDs having the corresponding wavelengths by using the illuminance variable device 400. That is, when the light intensity is larger than the actual sunlight as in 6A, the light intensity of the LED corresponding to the corresponding wavelength section is set to be weak, and the light intensity is compared with the actual sunlight as in 6B. Is small, the light intensity of the LED corresponding to the section of the corresponding wavelength is set strong.
By such a feedback function of the control unit 300, the simulated sunlight emitted from the light source unit 10 is reset so as to be approximated by sunlight, and the solar cell of the DUT 1 is placed under actual sunlight. The effect of inspecting and measuring the IV characteristic can be realized.

  FIG. 7 is a diagram illustrating a schematic configuration of a solar simulator according to a second embodiment of the present invention. This shows a case where the solar cell to be inspected for IV characteristics has a large area. A light source unit in which a plurality of LEDs are arranged in an array and a plurality of monitoring units 101 and 102 arranged for analyzing a light spectrum on one side of the DUT 1 are arranged. For example, the light source unit includes a first LED array 10a and a second LED array 10b, and each of the first and second LED arrays 10a and 10b includes a plurality of LEDs. Each LED can further be provided with an LED condensing lens 20 in order to improve the condensing efficiency.

Further, the LEDs that emit the respective unique wavelengths can be divided into the first LED array 10a or the second LED array 10b according to the wavelength length. For example, the first LED array 10a can be combined from LEDs that emit short wavelengths, and the second LED array 10b can be combined from LEDs that emit long wavelengths.
An integrator that synthesizes light and guides light with high illuminance to the device under test 1 side is arranged for each LED array. For example, it can be comprised from the 1st integrator 31 which synthesize | combines the light discharge | released from the 1st LED array 10a, and the 2nd integrator 32 which synthesize | combines the light discharge | released from the 2nd LED array 10b. Further, secondary condensing lenses 41 and 42 for improving the light condensing efficiency can be further provided at the front ends of the first and second integrators 31 and 32.

On both sides (or top and bottom) of the device under test 1, monitoring units 101 and 102 for monitoring the artificial sunlight incident on the device under test side are provided. The first monitoring unit 101 can analyze the illuminance and spectrum of the pseudo sunlight emitted from the first LED array 10a, and the illuminance of the pseudo sunlight emitted from the second LED array 10b by the second monitoring unit 102. Spectral analysis can be performed.
As described above, in order to vary the illuminance of the LED by the feedback function of the control unit, the spectrum analysis result is coupled to the first LED array 10a to vary the illuminance of the LED and the second LED array 10b. Then, a second spectrum variable device that varies the illuminance of the LED is provided.
The configuration of changing the illuminance of each LED by feeding back the illuminance and spectrum analysis of the simulated sunlight by the monitoring unit and the analysis result is the same as that in the first embodiment described above, and the description thereof is omitted. To do.
In FIG. 7, two sets of LED arrays, a first LED array and a second LED array, are arranged. However, an embodiment in which three or more sets are arranged depending on the size of the solar cell to be measured is also possible.

FIG. 8 is a diagram illustrating a schematic configuration of a solar simulator according to a third embodiment of the present invention. The solar simulator according to the third example is the same as the configuration of the first example or the second example except that a collimator lens 50 that converts the light that has passed through the integrator 30 into parallel light is further provided.
The light that has passed through the integrator 30 is converted into parallel light by the collimator lens 50, and uniform light is incident on the measured object side. Thereby, the illuminance of the pseudo-sunlight irradiated to each part of the solar cell of the object to be measured can be made uniform.

  According to the solar simulators of Examples 1 to 3 described above, the spectral characteristics can be maintained so as to approximate the simulated sunlight to sunlight, so that the IV characteristics of the solar cell can be accurately measured. .

DESCRIPTION OF SYMBOLS 1 Measured object 10 Light source part 30 Integrator 40 Secondary condensing lens 50 Collimator lens 100 Monitoring part 200 Characteristic analysis part 300 Control part 400 Illuminance variable apparatus

Claims (8)

A light source unit in which a large number of LEDs that emit a specific wavelength for irradiating the solar cell with simulated sunlight are combined;
The light that is incident from the light source unit is internally reflected a plurality of times inside and emitted to the solar cell side; and
A monitoring unit equipped with an illuminance monitor for measuring the illuminance of the pseudo-sunlight incident on the solar cell side;
A characteristic analysis unit for analyzing the illuminance of simulated sunlight measured through the monitoring unit;
In accordance with the analysis result of the characteristic analysis unit, a control unit that transmits a feedback signal to the light source unit side,
A solar simulator characterized by comprising:   The solar simulator according to claim 1, wherein the characteristic analysis unit further includes an IV analysis unit that analyzes an IV characteristic output from the solar cell.   The characteristic analysis unit includes an illuminance analysis unit that analyzes an illuminance characteristic, and the solar cell while the illuminance of the simulated sunlight is maintained constant for a predetermined time from the illuminance characteristics of the simulated sunlight analyzed by the illuminance analysis unit. The solar simulator according to claim 2, wherein the IV characteristic output from the power source is analyzed.   The solar simulator according to claim 1, wherein the monitoring unit further includes a spectroscope capable of measuring a spectrum of pseudo-sunlight incident on the solar cell side.   5. The characteristic analysis unit includes a spectrum analysis unit that compares a spectrum of pseudo sunlight measured by the spectrometer with a spectrum of sunlight, and transmits the analysis result to the control unit. The solar simulator described. An illuminance variable device that controls the illuminance emitted from each LED of the light source unit;
When the control unit determines that there is a spectrum distribution difference between simulated sunlight and sunlight, the control unit transmits a control signal for increasing or decreasing the illuminance of each LED to the illuminance variable device by a feedback signal. The solar simulator according to claim 5.   2. The solar simulator according to claim 1, wherein the LEDs of the light source unit are combined and arranged in an array at a predetermined interval around the integrator.   The solar simulator according to claim 1, wherein the integrator is configured by a collection of square or polygonal micro integrators.

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