Abstract

Increase in world demand load has resulted in new distributed generation (DG) that has entered into the power system. One of the most renewable energies is fuel cell, which is connected to power system using a power electronics interface in microgrid or standalone condition. The highest problem of this switching interface based DGs is the power quality (PQ) and harmonics of currents. Also, the voltage of the DGs should be controlled in islanding condition. In this paper, we present a Lead-Lag optimal controller for controlling one of the most important types of fuel cell, namely proton exchange membrane fuel cell (PEMFC) in islanding mode operation for reducing PQ problems and voltage control. At first, the introduction and implementation of the PEMFC is present and next, during system load variations the proposed controller is designed. The controller should be designed against the demand load variations of fuel cell. Here, the lead-lag controller is used when its coefficients are optimized based on honey bee mating optimization (HBMO). In order to use this algorithm, at first, the problem is written as an optimization problem which includes the objective function and constraints, and then to achieve the most desirable controller, HBMO algorithm is applied to solve the problem. Simulation results are done for various loads in time domain, and the results show the efficiency of the proposed controller in contrast to the previous controllers.

Key words: Power system, fuel cell.