文档介绍：Modeling and Control of a Single-Phase, 10 kW Fuel
Cell Inverter
Troy A. Nergaard
Thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University
in partial fulfillment of the requirements for the degree of
MASTERS OF SCIENCE
in
Electrical Engineering
Approved:
_______________________
Jason Lai, Chairman
___________________ ___________________
Dushan Boroyevich Douglas Nelson
July 25, 2002
Blacksburg, VA
Keywords: fuel cell, ultracapacitor, distributed generation, phase-shifted DC-DC
converter, single-phase inverter, voltage control
Copyright 2002, Troy Nergaard
Modeling and Control of a Single-Phase, 10 kW Fuel
Cell Inverter
by
Troy A. Nergaard
Electrical Engineering
Abstract
As the world’s energy use continues to grow, the development of clean distributed
generation es increasingly important. Fuel cells are an environmentally friendly
renewable energy source that can be used in a wide range of applications and are ideal for
distributed power applications. In this study, the power conversion element of a dual
single-phase, 10 kW stand-alone fuel cell system is analyzed. The modular converter
consists of a DC-DC front-end cascaded with a half-bridge inverter. The entire system is
accurately modeled, to help determine any interactions that may arise. Control strategies
based on simplicity, performance, and cost are evaluated. A simple voltage loop, with
careful consideration to avoid transformer saturation, is employed for the phase-shifted
DC-DC converter. Several experimental transfer functions were measured to confirm the
modeling assumptions and verify the control design of the DC-DC converter. Two
control options for the inverter are explored in detail, and experimental results confirm
that the modulation index must be controlled to regulate the output voltage during various
load conditions. The