Dual-Input Single-Phase Split Source Inverter for Optimized Power Extraction of Grid-Connected PV Systems Under Varied Atmospheric Conditions

This paper introduces an approach for optimizing power from distributed energy resources (DERs) through the Dual-input configuration of a single-phase split-source inverter (DSSI). The DSSI is engineered to maintain consistent performance, even when atmospheric conditions render one of its input sources inactive. The distinctive design of the DSSI enables both independent and combined processing of power from two DERs, featuring continuous current capability and effective mitigation of circulating currents. This is achieved by integrating the conventional SSI boosting feature with a continuous input current characteristic, allowing for the direct connection of low-voltage sources to the DSSI input ports. Such a connection eliminates the need for series connections, thereby enhancing the efficiency of maximum power point tracking and reducing the required capacitance values for power decoupling. A significant advantage of the DSSI is reduced hardware requirement. Unlike systems that use individual SSIs for each DER, the DSSI necessitates fewer switches and undergoes lower total volt-ampere stress. This reduction results in decreased costs, smaller size, simplified complexity, and attributed to fewer switch-driving circuits. Moreover, the DSSI adopts a simple unipolar modulation strategy, simplifying the operating states and stress management of semiconductors. The paper further discusses the implementation of a grid-connected control system within the renewable energy utilization system and keep regulating input currents and the DC-link voltage. The paper also presents experimental results for dual- and single-input scenarios along with variations on atmospheric conditions.