A Novel HTFIF Control with CSOGI-OSG Prefilter for Single-Stage SPVA System for Smooth Mode Transition Capabilities

This paper presents a novel hard-thresholding fast iterative filtering (HTFIF) control for a grid-tied solar photovoltaic array (SPVA) system. The effectiveness of this control is tested during grid-connected mode (GCM) in different dynamic conditions like grid outage, variable irradiance, and load unbalancing. A cascaded reduced order generalized integrator orthogonal signal generator (CROGI-OSG) is used as a pre-filter to eliminate the harmonics in grid voltage. The system is designed to operate independently as a Standalone Mode (SAM) when the grid is not accessible. During SAM, a Proportional+Resonant (PR) controller is employed to counteract the oscillatory components in the load voltage. A double frequency and amplitude compensation (DFAC) phase-locked loop (PLL) is used for a smooth transition between GCM and SAM. The effectiveness of the presented control with pre-filter and PLL is evaluated in MATLAB/Simulink environment.