A Novel Power Electronic Converter Controller Based on A Two-Level Pyramid Architecture to Enhance Power Quality in Grid-Tied PV Systems

The rapid integration of photovoltaic (PV) systems into the power grid has become more prevalent, necessitating enhancement for reliable and effective power quality (PQ) control. However, the nonlinear characteristics of the power electronic components (PECs) introduce significant PQ and reliability issues. In order to mitigate these challenges, this paper proposes a novel PEC controller for shunt active power filters (SAPF) to improve PQ and facilitate the seamless integration of PV systems to the grid. The proposed controller utilizes only two levels of discrete low-pass filters (LPFs) with inherent cut-off frequency and damping factors. This controller effectively extracts the fundamental frequency dc component from distorted and unbalanced load currents within the stationary reference frame. The controller achieves faster dynamic performance with less than a quarter-cycle delay in compliance with the IEEE 512 standard. The test system is simulated under adverse and varying grid conditions employing the MATLAB/Simulink and PLECS tools. The proposed controller is validated against the well-known synchronous reference frame controller for SAPF as a benchmark. Also, a reliability analysis of the PV's PEC components is conducted to identify the most reliable condition based on the PEC's reliability.