Power Source Management for Direct Methanol Fuel Cells without Using Concentration Sensors

Abstract

Among many kinds of fuel cells, the direct methanol fuel cell (DMFC) is very emphasized for low power applications, for example, for 3C-products. The main issue of this paper focuses on the power source management system of DMFC. An effective method for maintaining methanol concentration, called Voltage Double Check Concentration Control (VDC^3) will be proposed. Considering the features of transient response caused by loading change, the proposed algorithm can judge whether the methanol concentration is insufficient or not. Then, pure methanol will be injected at correct timing to maintain the methanol concentration in a suitable range.