Novel High-Performance Stand-Alone Solar PV System With High-Gain High-Efficiency DC–DC Converter Power Stages

Abstract

This paper proposes a novel 3Φ stand-alone solar photovoltaic (PV) system configuration that uses high-gain high efficiency (≈ 96%) dc-dc converters both in the forward power stage and the bidirectional battery interface. The high-voltage gain converters enable the use of low-voltage PV and battery sources. This results in minimization of partial shading and parasitic capacitance effects on the PV source. Series connection of a large number of battery modules is obviated, preventing the overcharging and deep discharging issues that reduce the battery life. In addition, the proposed configuration facilitates “required power tracking (RPT)” of the PV source as per the load requirements, eliminating the use of expensive and “difficult to manage” dump loads. High-performance inverter operation is achieved through abc to dq reference frame transformation, which helps in generating precise information about the load's active power component for RPT, regulation of ac output voltage, and minimization of control complexity. Inverter output voltage is regulated by controlling the modulation index of sinusoidal pulsewidth modulation, resulting in a stable and reliable system operation. The active power demand is controlled by regulating the dc link voltage. All the analytical, simulation, and experimental results of this work are presented.