Development for portable system of solar cell parameters acquisition

In order to fulfill rapid and accurate acquisition of the solar cell photoelectric characteristic eleven parameters (including the photocurrent, reversed saturation current, ideality factor, series resistance, shunt resistance, short circuit current, open circuit voltage, maximum output power, best working voltage, best working current and fill factor), a testing system, that consists of six parts (including the sun simulator module, control and processing module, electronic loads module, signal collection module, key input module and display output module), was developed. The main features of the system are that, programmable constant current and voltage electronic load and sampling frequency conversion technique are used to realize an accurate measurement of current and voltage, after integrating solar cell parameters analytical extraction algorithm into the digital signal processing chip, the cell parameters, for example, photocurrent, can be acquired conveniently. The results show that the mean square error of current-voltage curve fitting of a mono-crystalline silicon solar cell under different light intensities is less than 0.006 A, which proves that the obtained eleven parameters are correct.