AFFTOGI Control for Power Quality Improvement and Seamless Transition in Grid-Tied SPV-BES System

This paper presents a solar photovoltaic (SPV) array-battery energy storage-based microgrid with a two-stage converter. One is a DC-DC converter, and another one is a voltage source converter (VSC). It acts in standalone mode or grid-connected mode depends on utility grid conditions. A bidirectional DC-DC converter (BDC) is used for maintaining the DC link voltage. Maximum power point tracking (MPPT) with an incremental conductance (INC) technique is used to extract the maximum power from the SPV array. Adaptive fixed frequency third-order generalized integrator (AFFTOGI) controller is used for estimating the load fundamental and quadrature components from the distorted grid and unbalanced load. In grid-connected mode, VSC works in current control mode, and in standalone mode, it works in voltage control mode. In this paper, dynamic simulation under different operation conditions and experiments on developed laboratory prototypr are performed to evaluate the system and control algorithm performance.