Adaptive Fourth-Order GI-Based Controller for Three-Phase Grid-Tied Solar Photovoltaic System

Abstract

A fourth-order generalized integrator (GI)-based frequency locked loop (AFOGI-FLL) controller is proposed to provide switching pulses for a three-phase IGBT-based voltage source converter. Accurate frequency synchronization, lower- and higher-order harmonic elimination, power quality refinement, and reactive power compensation are the features of the presented controller. As a renewable energy solution to meet energy demands, grid-interfaced photovoltaic systems are described in this paper. To stabilize DC link voltage, a novel ANFIS-based hybrid intelligent controller is proposed. In addition, a comparative analysis has been performed between the proposed controller and the third-order generalized integrator (TOGI). The comparative analysis results show that fourth-order generalized integrator has higher DC offset elimination capability and better dynamic performance as well and THD is less compared with the TOGI controllers. The THD of the proposed controller is 1.10% which is less than the IEEE standard. The proposed controller robustness is validated by an experimental prototype setup and test results exhibit the performance under non-linear loading. Additionally, the feasibility of the proposed control scheme is demonstrated by using MATLAB/SIMULINK software. The system is well executed under irradiance variations, load fluctuations, and frequency variations as well. The laboratory prototype is used to demonstrate the proposed system's simulated behavior and experimental test results.