Optimising I-V measurements of high capacitance modules using dark impedance measurements

A method is demonstrated to optimise pulsed IV measurements of high capacitance PV modules, using dark IV and impedance measurements. The impact of capacitance during I-V measurements is minimised by changing the shape of the voltage ramp. The optimisation can be performed simply and automatically for each individual module during the charging period for the simulator. As an additional benefit of this method the extracted C-V profile can be used to estimate the minority carrier lifetime for the module. The system is demonstrated by using a high capacitance n type module, which is successfully measured in a single 10ms illumination pulse.