A Thermally Dependent Fuel Cell Model for Power Electronics Design

In the dawn of the fuel cell era, it may seem that their development and use would still be immature. However, this is not true - fuel cells are finding use in everything from cell phones to automobiles quite quickly. Regardless of their application, the fuel cell must be accurately modeled in the system it will be used in. Such a model must be simple, easy to use, and fast to simulate. Chemistry, material science, and physics must be transformed into electrical components and systems that work easily in programs like Pspice, Saber, Labview, and the like. Herein, such a model is presented in its latest form, incorporating dynamic effects of heating and cooling of the stack

I. Introduction

Fuel cells are becoming more prevalent and the importance of accurately modeling their electrical performance is crucial to the success of any fuel cell based power system development. The governing equations of the electrochemical process, the time constants in mass transport, and the hydration of the membrane are well known and accurately describe the Proton Exchange Membrane (PEM) fuel cell polarization curve. The purpose of this work is not to reiterate or validate these principals – it is to present a thermally dependent electrical model of a commercial fuel cell system. Without such a model, the power electronics circuit designer is forced to rely on experimental verification during the crucial cold start and temperature transient operation of the fuel cell.