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The following table should outline results from varying the E-load and intensity of the sunlight. The first cell in series was isolated, and attached to an E-load.
| Light Source | V(out)oc | E-Load Setting | Measured Voltage input input (using dmm on input terminals of mppt) | Measured Voltage Output | Measured Current | extra notes |
|---|---|---|---|---|---|---|
| Sunlight | 25.131 | |||||
| Clouds | 16.2 | 7.0kohm | 0.171 | 10.03 | 0.0014 | |
| Clouds | 16.2 | 10ohm | 0.171 | 0.155 | 0.0152 | |
| Clouds | 16.2 | 70W | basically 0 | 0.015 | ||
| 240W light | 9V | 5ohm | 0.068V | 0.227 | 0.0422 | reading the vout from mppt was 0.56V while output from solarsenseslave was 0.056V |
| 240W light | .866 (dmm) 25V(eload off) | 5ohm | .316 | .285 | 0.0566 | |
Note: when the Mppts are lit by the light outside on a fully cloudy day, the mppt goes into short circuit mode where it provides basically no output voltage increase for a normal resistance on the line. However, using the 240W flashlights provided by Micah, we are able to see a huge increase in the voltage input and the voltage out on the line (from 15V(out)oc when cloudy to 25V(out)oc). On a sunny day outside the voltage output from the mppt is still 25V which is pretty good.
Another note: the voltage on the input of the mppt changes drastically when the outside environment does not even change. For example, the voltage output(oc) was 15V, which changed to 25V after several minutes and changed to 8.8V after several more minutes of doing nothing (same light source and intensity).
String Testing of MPPTs
Each MPPT once unit tested, will be tested in series for the total array output power, and continuity. Like unit testing, this will be run for at least half an hour for full validation.
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