LED Performance for Light Intensity Modulation Impedance Spectroscopy of Photovoltaic Modules

This paper addresses the light-emitting diode (LEDs) performance for Photovoltaic (PV) light intensity modulated impedance spectroscopy (LIMIS). An investigation of PV module response with different LEDs’ spectra is important in order to obtain proper PV response. This paper presents six different LEDs color spectra and the PV voltage and current responses. To validate LED’s performance, the LED light modulated testbed is constructed with four LEDs arrays with total 400W, simple driver control, and impedance measurement. The PV powers with respect to cool white, warm white, white, natural white, full spectrum and royal blue LEDs are 8.4; 8.0; 7.8; 7.5; 5.2; and 4.8 W, respectively at 425W input power condition. The selected cool white LEDs are suitable for PV impedance test and will provide enough current for the impedance measurement.