Two sets of capacitor load based I-V curve tracer for
photovoltaic cell are designed and implemented (Test system one
includes Raspberry Pi, capacitor, current sensor, and
analog-to-digital converter, etc.; test system two includes data
acquisition card, capacitor, and sampling resistor, etc.). The
conclusions are made: (1) the measurement results of both systems
are generally correct, but neither can obtain short-circuit current
due to the inability to achieve a load resistance of zero. Test
system two based on the data acquisition card is found to be higher
accuracy. (2) The factors affecting the accuracy of test system two
is studied. The larger capacitance leads to more precise measured
data. Smaller sampling resistors result in output voltages closer to
zero and more complete I-V curves. When the sampling rate is
high, noise may cause oscillating I-V curve.