Power conditioner based fuel cell and backup power system with supercapacitor

Abstract

PEMFCs are the most popular type of Fuel Cells (FCs) and traditionally use hydrogen as the fuel. One FC problem is its relative slow dynamics caused by the time constant of the hydrogen and oxygen supply systems that can be in the range of several seconds. In this sense, supercapacitors (SCs) respond faster than FC to a fast increase or decrease in power demand. Thus, using SCs together with FCs improves FC life and performance by absorbing faster load changes and preventing fuel starvation of the FC. Therefore, it becomes necessary to study structures of power conditioners with their respective control systems that can mitigate the disadvantages mentioned of the FC itself. Several researches have studied the different topologies with their respective control proposals to operate FC and SC. This thesis proposes a digital control scheme to operate a PEMFC module of 1.2 kW and a SC through a DC/DC hybrid converter. A FC has been proposed as a primary source of energy and a SC has been proposed as an auxiliary source of energy. An experimental validation of the system implemented in the laboratory is provided. Several tests have been performed to verify that the system achieves an excellent output voltage (V0) regulation and SC Voltage (VSC) control, under disturbances from FC power (PFC) and output power (P0) as well as other perturbations described in analysis results.

Key findings

• ▸The use of supercapacitors with fuel cells improves fuel cell life and performance by absorbing fast load changes and preventing fuel starvation.
• ▸A digital control scheme is proposed to operate a 1.2 kW PEMFC module and a supercapacitor through a DC/DC hybrid converter.
• ▸Experimental validation of the system is provided, showing that it can achieve the desired performance.

Keywords

Identifiers

DOI

10.5821/dissertation-2117-94661

Journal

Unknown journal

Year

2012