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| university:courses:alm1k:alm-lab-pv [16 Jan 2017 20:42] – [Procedure:] Doug Mercer | university:courses:alm1k:alm-lab-pv [10 Mar 2022 15:12] (current) – [Hardware Setup:] Doug Mercer |
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| ======Activity : Characteristics of Photovoltaic Solar Cells====== | ======Activity: Characteristics of Photovoltaic Solar Cells - ADALM1000====== |
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| =====Objective:===== | =====Objective:===== |
| Set the voltage vertical scale of scope channel A to 0.5V/div. The current vertical scale of channel A will depend on the maximum current your panel can generate. | Set the voltage vertical scale of scope channel A to 0.5V/div. The current vertical scale of channel A will depend on the maximum current your panel can generate. |
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| Set the frequency of waveform generator A to 100 Hz, and the horizontal time base so that at least one full 0 to V<sub>OC</sub> sweep is displayed. With the channel A generator disabled, first measure the open circuit voltage produced by the panel when in full sun light. Set the Max voltage of waveform generator A to the open circuit voltage you just measured. Set the Min voltage of waveform generator A to 0. Now enable the channel A generator to force voltage. | Set the frequency of waveform generator A to 100 Hz, and the horizontal time base so that at least one full 0 to V<sub>OC</sub> sweep is displayed. Set the channel A wave Shape to Triangle as indicated in figure 9 or 10. The linear triangle is best for sweeping a voltage but a sine wave can be used as well. |
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| | With the channel A generator disabled (in Hi-Z Mode), first measure the open circuit voltage produced by the panel when in full sun light. Set the Max voltage of waveform generator A to the open circuit voltage you just measured. Set the Min voltage of waveform generator A to 0. Now enable the channel A generator to force voltage. |
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| ====Procedure:==== | ====Procedure:==== |
| Ideally you should take data outside under constant temperature and sunlight conditions - i.e. no clouds. This may not always be practical depending on the computer used with the M1000 hardware. A sun facing window would work but it would be best to open the window and remove any shades or screens that might reduce the amount of sunlight. You should also make your measurements quickly to avoid the heating of the panel from the direct sunlight that may then change the characteristics during the data-collection. Make sure that you don't cast any shadows or reflections over the panel during the experiment. Once you have fixed the position of the panel with relation to the sun it is NOT TO BE MOVED DURING THE EXPERIMENT. | Ideally you should take data outside under constant temperature and sunlight conditions - i.e. no clouds. This may not always be practical depending on the computer used with the M1000 hardware. A sun facing window would work but it would be best to open the window and remove any shades or screens that might reduce the amount of sunlight. You should also make your measurements quickly to avoid the heating of the panel from the direct sunlight that may then change the characteristics during the data-collection. Make sure that you don't cast any shadows or reflections over the panel during the experiment. Once you have fixed the position of the panel with relation to the sun it is NOT TO BE MOVED DURING THE EXPERIMENT. |
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| Once you have obtained an I/V plot using the Waveforms software, export a data file in .csv format. Load the .csv data file into a data analysis software program like MatLab or a spreadsheet (Excel). You should have adjusted the horizontal time base of the scope to display a little more than one sweep of the voltage ramp. Your output data file will probably contain more than one set of voltage and current values from 0 to V<sub>OC</sub>. You should remove this extra data before generating a plot of your data. You should also calculate the power ( I*V ) for each data point. From your I/V curves calculate values for the fill factor, FF, P<sub>MAX</sub>, maximum efficiency η<sub>MAX</sub> (based on approximately 1mW/mm<sup>2</sup>for the incident light power) R<sub>S</sub> and R<sub>SH</sub>. | Once you have obtained an I/V plot using the X-Y plotting tool in the ALICE desktop software, export (save) a data file in .csv format. Load the .csv data file into a data analysis software program like MatLab or a spreadsheet (Excel). You should have adjusted the horizontal time base of the scope to display a little more than one sweep of the voltage ramp. Your output data file will probably contain more than one set of voltage and current values from 0 to V<sub>OC</sub>. You should remove this extra data before generating a plot of your data. You should also calculate the power ( I*V ) for each data point. From your I/V curves calculate values for the fill factor, FF, P<sub>MAX</sub>, maximum efficiency η<sub>MAX</sub> (based on approximately 1mW/mm<sup>2</sup>for the incident light power) R<sub>S</sub> and R<sub>SH</sub>. |
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| Repeat taking data for other positions where the panel faces away from the sun. | Repeat taking data for other positions where the panel faces away from the sun. |
| Suppliers: | Suppliers: |
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| http://www.bgmicro.com/PWR1241.aspx\\ | [[https://www.allelectronics.com/item/spl-30/solar-cell-3v-40ma/1.html|SOLAR CELL, 3V 40MA]]\\ |
| http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1928142_-1 | |
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| OSEPP SC10072 Monocrystalline Solar Cell - Barrel Plug Termination, 100mA I<sub>SC</sub>, 7.2 V<sub>OC</sub>. This one comes prewired with a power plug. A matching jack would be needed to connect the panel to your experiments. | OSEPP SC10072 Monocrystalline Solar Cell - Barrel Plug Termination, 100mA I<sub>SC</sub>, 7.2 V<sub>OC</sub>. This one comes prewired with a power plug. A matching jack would be needed to connect the panel to your experiments. |
| The regulated output voltage will be equal to the V<sub>BE</sub> of transistor Q<sub>1</sub> plus the forward drop of LED<sub>1</sub>. The current in the LED is set by the value of R<sub>1</sub> and the V<sub>BE</sub>. A range of output voltages are possible by choosing different color LEDs. The forward voltage drop can range from around 2 V for red and up to 3 V for blue or white. Even more output voltage values can be made by inserting the forward voltage drop of one or more standard Si diodes in series with the LED. | The regulated output voltage will be equal to the V<sub>BE</sub> of transistor Q<sub>1</sub> plus the forward drop of LED<sub>1</sub>. The current in the LED is set by the value of R<sub>1</sub> and the V<sub>BE</sub>. A range of output voltages are possible by choosing different color LEDs. The forward voltage drop can range from around 2 V for red and up to 3 V for blue or white. Even more output voltage values can be made by inserting the forward voltage drop of one or more standard Si diodes in series with the LED. |
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| Looking at the version on the right, NPN transistor Q<sub>1</sub> and collector resistor R<sub>2</sub> form a common emitter amplifier stage. PNP transistor Q<sub>2</sub> provides current gain. As soon as enough current is flowing through the LED and R<sub>1</sub> such that the voltage across R<sub>1</sub> is large enough to turn on Q<sub>1</sub> the circuit starts to regulate. Beyond the initial startup current in the LED, the majority of the current through the shunt regulator flows through Q<sub>2</sub>. The above explanation similarly holds for the complementary version on the right. | Looking at the version on the left, NPN transistor Q<sub>1</sub> and collector resistor R<sub>2</sub> form a common emitter amplifier stage. PNP transistor Q<sub>2</sub> provides current gain. As soon as enough current is flowing through the LED and R<sub>1</sub> such that the voltage across R<sub>1</sub> is large enough to turn on Q<sub>1</sub> the circuit starts to regulate. Beyond the initial startup current in the LED, the majority of the current through the shunt regulator flows through Q<sub>2</sub>. The above explanation similarly holds for the complementary version on the right. |
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| {{ :university:courses:alm1k:alm-lab-e2_a5.png?550 |}} | {{ :university:courses:alm1k:alm-lab-e2_a5.png?550 |}} |
| <WRAP centeralign>Figure A2 Shunt Regulator with negative feedback</WRAP> | <WRAP centeralign>Figure A2 Shunt Regulator with negative feedback</WRAP> |
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| **Return to ALM Lab Activity [[university:courses:alm1k:alm-labs-list|Table of Contents]]** | **Return to [[university:labs:intro_ee|Introduction to Electrical Engineering]] Lab Activity Table of Contents**\\ |
| | **Return to [[university:courses:alm1k:alm_circuits_lab_outline|Circuits]] Lab Activity Table of Contents**\\ |
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