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

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 ofa 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.