Power Quality Enhancement using a FOPID–Controlled Quadratic Boost Converter Integrated Hybrid Active Filter

This work presents an integrated renewable energy interfacing system that combines a Quadratic Boost Converter (QBC) with a Hybrid Active Filter (HAF) to enhance power quality and voltage regulation in photovoltaic (PV) and battery-supported hybrid energy sources. The coordinated operation of the converter–filter system is supervised by two closed-loop controllers: a classical Proportional–Integral (PI) controller and a Fractional-Order Proportional–Integral–Derivative (FOPID) controller. The controllers are designed to regulate the DC-link voltage of the QBC while ensuring harmonic suppression in the grid-side current. The Simulink-based evaluation demonstrates that the FOPID regulator delivers faster transient response, improved steady-state accuracy, and reduced harmonic distortion compared to the conventional PI scheme, making the topology suitable for power-quality enhancement in distributed renewable systems.