Smooth Changeover to On-Grid and Off-Grid of a Double-Stage Solar PV-BES-Based Distributed Generation System

In this paper, a solar photovoltaic (PV) based doublestage distributed generation system (DGS) in grid-connected mode (GCM) and standalone mode (SAM) with load balancing, harmonics deduction and seamless transition using adaptive historical weighted step size least mean square (HWSS-LMS) control technique is presented. This DGS includes a battery with a bidirectional DC-DC converter (BDDC), local nonlinear loads, solar PV array, and a voltage source converter (VSC). The solar PV-battery system adds additional solar generation power to the grid. Additionally, it has a dual capability for operating in both SAM and GCM. Here, the peak power from the PV distributed generation is harvested employing a maximum power point tracking (MPPT) technique based on perturb and observe (P&O) approach. A boost converter connects the solar PV array to the DC-link, and the BDDC is employed to retain the DC-link voltage while transmitting active power. Additionally, the adaptive control mechanism in GCM offers a seamless operation while eliminating the harmonics under various loading circumstances. However, in the synchronization mode, the phase-locked loop (PLL) is utilized to determine the angles associated with the load and grid voltages.