Fuel Cell for Standalone Application Using FPGA Based Controller

Abstract

Currently, escalation in consumption of energy, instability of crude oil price and global environment change has forced researchers to focus more on renewable energy sources. There are different new and renewable energy sources (such as photovoltaic and wind energy), however each possess some limitations or other. Fuel Cell is an important alternative that can be compared to other new and renewable sources of energy and proved to be better in certain terms and Solid oxide fuel cell (SOFC) is a more efficient, environmental friendly renewable energy source. This paper focuses on load/grid connected fuel cell power system (FCPS) which can be used as a backup power source for household and commercial units. This backup power source would be efficient and will provide clean energy at an affordable per unit cost. Load/grid connected fuel cell power system mainly comprises a fuel cell module, DC-DC converter and DC-AC inverter. This work primarily focuses on solid oxide fuel cell (SOFC) modelling, digital control of DC-DC converter and DC-AC inverter. Extensive simulation is conducted to validate our concepts and some experimental results confirm the same. Dynamic mathematical model of SOFC is developed to find out output voltage, efficiency, and losses in fuel cell stack. One output from fuel cell is DC voltage that is fed to a DC-DC converter for stepping up as usually this is a low voltage. Proportional-Integral (PI) controller and FPGA based PI controller are implemented and experimentally validated. The prototype of single phase system having fuel cell as input and delivering ac power is developed. FPGA (Field Programmable Gate Array) implementation of HCC is done using NI-cRIO-9014. FPGA implementation of three phase model of fuel cell power system is developed using adaptive-fuzzy-HCC using Xilinx/System Generator.