Evaluating Technical Requirements to Achieve Maximum Power Point in Photovoltaic Powered Z-Source Inverter

Abstract

One of the key challenges of employing photovoltaic systems is to extract maximum power of the panels. This problem is known as maximum power point tracking (MPPT) technique. The MPPT stands for establishing situation in which output power of the panels reaches its maximum allowable power. In this context, this paper is to assess the technical requirements to achieve maximum output power of a number of photovoltaic (PV) panels in Z-source inverters. For the sake of simplicity and without loss of generality, a generic 7-level Z-source multi-level inverter to use with the PV panels is considered for our purpose. The conducted assessment is performed in terms of the analysis of the input resistance of the connected inverter. The simulation results showed that achieving the maximum power point (MPP) depends on the various governing factors including components of the inverter (i.e. load, frequency switching, and electric elements value), irradiance level, ambient temperature, and partial shading effect. Also, as the results demonstrate, in a number of combinations of the conditions there is not an optimum situation in terms of achieving MPPT. In addition, major parts of the findings are implemented on a practical system.