Power Quality Improvement of a Fuel Cell-Powered Filterless Distributed Generation System Using Sinusoidal Pulse Width Modulation

Abstract

This paper proposes a distributed generation system based on fuel cells and batteries. The primary energy source for the distributed generation system is a proton exchange membrane fuel cell, with a lead-acid battery serving as the energy storage medium. A boost converter regulates the output power of a fuel cell to guarantee smooth operation. The battery is connected with the fuel cell to meet the power demand of the distributed generation system. A buck-boost bidirectional converter is employed as an interface between the battery and the DC link capacitor. The bidirectional converter operates on the slope compensated current control approach. Two 5-level cascaded H-bridge inverters have been installed to improve the power quality of distributed generation systems. The power flow between the source, grid, and nonlinear load is controlled using a sinusoidal pulse width modulation approach. Nonlinear current compensation and capacitor voltage balancing are two features that improve power quality.