Dynamic Models for PEMFCs and Tubular SOFCs

Caisheng Wang and M. Hashem Nehrir
 

I. PEMFC

Introduction

A physically-based dynamic model for a PEM Fuel Cell (PEMFC) stack has been developed at Montana State University using MATLAB/SIMULINK. An equivalent electrical circuit model for the same PEMFC stack has also been developed using PSpice. Both models have been validated with experimental data obtained on a 500-W Avista (now Relion) PEMFC stack. The models can be used in studies related to PEMFC performance evaluation, controller design, fuel cell vehicles, stand-alone and grid-connected (distributed) fuel cell power plants, to name a few.

This research work was supported by the U.S. National Science Foundation under Grant No. 0135229. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

PEMFC Model Description

The MATLAB/SIMULINK simulator is most appropriate for system level studies such as controller design, parameter sensitivity analysis, and determining the effect of load transients on fuel cell performance. The PSpice equivalent electrical circuit simulator is developed for circuit level simulation studies and controller design. The details of model development and its application in fuel cell distributed generation (FCDG) studies have been reported in the following papers.

  • C. Wang, M.H. Nehrir, and S.R. Shaw, “Dynamic Models and Model Validation for PEM Fuel Cells using Electrical Circuits,” IEEE Transactions on Energy Conversion, Vol. 20, No. 2, pp 442-451, June 2005.
  • C. Wang, M.H. Nehrir and H. Gao, “Control of PEM Fuel Cell Distributed Generation Systems,” IEEE Transactions on Energy Conversion, Vol. 21, No. 2, pp. 586-595, June 2006.

II. SOFC

Introduction

A physically-based dynamic model for a 5 kW tubular solid oxide fuel cell (SOFC) stack has been developed at Montana State University using MATLAB/SIMULINK. The model responses have been compared with Solid-State Energy Conversion Alliance (SECA) model and industry data. The model can be useful in SOFC related studies such as real-time control of SOFC and its distributed generation applications.

This research work was supported by the HiTEC fuel cell project at Montana State University, funded by the United States Department of Energy, as a subcontract from Battelle Memorial Institute and Pacific Northwest National Laboratory (PNNL) under Award No. DE-AC06-76RL01830. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation and the Department of Energy.

SOFC Model Description

The model is composed mainly of an electrochemical part and a thermal dynamic part. It has 9 input quantities and two main outputs. The scope blocks are used in the model to measure the following quantities: Load current, FC output power, FC output voltage, FC temperature, activation voltage drop, ohimc voltage drop, concentration voltage drop, fuel utilization and effective partial pressure of H2, H2O and O2. The details of the model development and its application in fuel cell distributed generation (FCDG) studies have been reported in the following papers in the IEEE Transactions on Energy Conversion, Vol. 22, No. 4, December 2007.

  • C. Wang and M.H. Nehrir, “A Physically-Based Dynamic Model for Solid Oxide Fuel Cells.”
  • C. Wang and M.H. Nehrir, “Overloading capability and Distributed Generation Applications of Solid Oxide Fuel Cells.”
  • C. Wang and M.H. Nehrir, “Load Transient Mitigation for Stand-alone Fuel Cell Systems.”

We ask that those who use the models for research or education acknowledge their use when reporting their works. Although the models have worked successfully, it is understood that the users will use them at their own will, and the above authors and Montana State University accept no responsibility regarding the operation of the models. These models are intended for educational and research use only, and by downloading the files the users agree that they will not use the models for commercial purposes.