Analysis of the effects of inverter ripple current on the photovoltaic power system

Abstract

Most of the solar cell models suggested so far is mainly employing the steady state modeling methods to estimate the characteristic I-V curve of the solar cell at a certain operating point. Thus, the study on the dynamic characteristics of the solar cell can be rarely found. For the design of high performance power conditioning unit, it is essential to have the accurate information about the static and dynamic characteristics of the solar cell. In this study AC impedance model of the solar cell module is developed using Impedance Spectroscopy and used for evaluating the effects of the ripple current generated by the single phase inverter. It is proven by the experiments that the energy conversion efficiency of photovoltaic power system may be significantly reduced in case the 120Hz ripple current generated by the single phase inverter is larger than a certain value and appropriate limit value for the 120Hz ripple current is also suggested.