Measurement of solar cell ac parameters using the time domain technique

The instrumentation to measure solar cell ac parameters [cell capacitance $(C_P)$ and cell resistance $(R_P)$] using the time domain technique is developed. The cell capacitance $(C_P)$ and series resistance (r) are calculated using open circuit voltage decay (OCVD) technique. It is calibrated with the help of an electrical network with passive components similar to ac equivalent circuit of a solar cell consisting of precision resistors and capacitors. The maximum error observed in the measurement of resistor and capacitor value is ±3.5%. The cell resistance $(R_P)$ is calculated from I–V characteristics of solar cell. The data obtained in time domain technique is compared with the impedance spectroscopy technique data measured on same solar cell and it is found that the deviation in cell capacitance and resistance are within ±8%