Quadratic Boost Converter with integrated Energy Storage using PI controller for Low Power Photovoltaic Applications

Abstract

Quadratic boost converter with integrated energy storage is designed for low power photovoltaic application. Though the electric power produced by photovoltaic panel provides several advantages like availability of resources for free, maintenance free and long life time, it suffers from intermittent power production, thus creating an unstability in power supplied to load. This disadvantage is overcome by connecting a battery in parallel with one of the capacitors of quadratic boost converter. The battery discharges and charges automatically without the bi-directional converter, whenever photovoltaic panel power becomes greater than or becomes less than load power, thereby maintaining the power supplied to load constant. Battery discharging and charging transients happen without affecting operation mode of converter. Simplicity, high voltage gain and lesser ripple in input side voltage and current make quadratic boost converter an appropriate converter suitable for photovoltaic applications. A PI controller with inner current controlled loop and outer voltage controlled loop has been designed to obtain voltage regulation at output load side against input side PV panel voltage change with change in insolation. The designed system has been validated with simulation and hardware circuit.