Pem fuel cell stack modeling and design of DC/DC converter for fuel cell energy system

Abstract

The main objective of the research is twofold: 1) Fuel cell stack modeling; 2) DC/DC converter design. The aim of the first aspect of the research is to develop a simple and accurate fuel cell stack model which can predict both steady-state and dynamic behavior of the stack. A hybrid model is designed to describe the stackb s steady-state characteristics, charge double layer dynamics and temperature effects. ANN technique is used to model the nonlinear subsystem to improve the model dynamic accuracy and flexibility. The other aim of the research is to design a proper DC/DC converter for fuel cell based power supply. An interleaved current-fed full bridge converter (ICFFB) is designed with parallel input/series output scheme, which can achieve small input current ripple, reduced size of magnetic components, high efficiency and soft start-up capability. A cascaded PI controller and a combined feed-forward/feedback controller are designed to control the ICFFB converter.