Implementation of a Switching Matrix Operating PV Field-Storage Interconnection

Abstract

The need to find an alternative to traditional energy sources has led to a strong growth in electricity production from renewable sources; among these, a widespread source of electricity is solar energy. Due to the nature of this energy source, one of the main limits of photovoltaic (PV) systems is the partial shading of the modules, due to weather conditions or cleaning of the module. In these conditions, the value of the PV generator voltage drops below the minimum power range of the solar inverter. To exceed this problem a solution to extend the Maximum Power Point Tracking (MPPT) range of the solar inverter is proposed; it consists of a control logic for the series connection between the PV source and a storage system, e.g. a battery, including a DC/DC converter, automatically by means of a switching matrix. Based on the values of the control quantities - PV generator voltage and State Of Charge (SOC) of the storage system- the system provides the proper commands to the switches. In this way the Battery Energy Storage System (BESS) is enabled to boost the input voltage of the solar inverter achieving the voltage minimum power point limit and avoiding any disconnection of the equipment.