Modeling and Control of a Single-Phase, 10 kW Fuel Cell Inverter

As the world's energy use continues to grow, the development of clean distributed generation becomes 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 final system is implemented without the use of current sensors, thus keeping the inverter cost down. Experimental results using a power supply are given for resistive, inductive, and nonlinear loads and the performance is acceptable. Fuel cell test results, including transient response, are also displayed and analyzed.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2002

Author dc:creator

• Nergaard, Troy

Chair dc:contributor.committeechair

• Lai, Jih-Sheng

Committee members dc:contributor.committeemember

• Boroyevich, Dushan
• Nelson, Douglas J.

• ultracapacitor
• distributed generation
• phase-shifted DC-DC converter
• voltage control

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-07262002-163508

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/34180