An improved maximum power extraction scheme for microbial fuel cells

Microbial fuel cell (MFC) is a recent technology of producing bioelectricity from wastewater by using bacteria as catalyst in the oxydo-reduction reaction. Because of the biological nature of MFC, the level of delivered electrical power is greatly affected by the operating conditions. In order to extract the maximum produced power, extremum-seeking control (ESC) methods are used to keep MFC working at its optimal operating point. As the ESC scheme is based on a feedback control loop, its performance can be limited in presence of high frequency disturbances. In this paper a method is proposed to improve the performance of the well-known perturbation method in presence of frequent variations of the inlet substrate concentration which is considered here as a disturbance for the MFC.