Harvester Frontend Validation

Test of various harvesting algorithms with a solar cell

solar cell: IXYS SM101K09L
lighting by philips LED 9W 806 lm, 50 Hz
harvesting Profiles in detail
Plots show
- a general overview while the lighting was moved
- an area with low light
- an area with bright light and eventually a detailed shot of the measurement
interesting findings
- voc: setpoint of 76 % in low-light seems off ⇾ is the VOC wrong?
- voc & iv: opening the circuit lets the voltage rise significantly above VOC (especially in low light scenario) and it takes time to stabilize
- voc: jumping to setpoint lets the power increase for a short time in bright light (hidden capacitor?)
- iv: sawtooth-ramp is highly non-linear in the cross-section coming from VOC (1000 Hz, bright light detail)
- iv: current measurement is delayed for a timeslot (obvious in scenario “1000 Hz bright light detail” @ 0V
- all: bright details show 50 Hz line frequency of LED
- all: detail-shots show a 5 kHz and 50 kHz resonance for high currents
- iv open input: voltage seems to follow despite no driving source