Approximation of Fuel Cell Characteristic Curves for Maximum Power Point Tracking

A curve fitting method that approximates the power vs. current characteristic curve of a given fuel cell with a quadratic is presented. The coefficients of the approximated P-I characteristic curve are strongly dependent on pressure. The strong dependence of the P-I curve on pressure allows the P-I characteristic curve of a given system to be written as a function of both fuel cell current and pressure. The curve fitting method presented can be used in an indirect maximum power point tracking algorithm for use with fuel cell powered systems. Experimental results are presented to confirm the validity of the method.