Current stabilization in fuel cell/battery hybrid system using fuzzy-based controller

In recent years, fuel cells are emerging as main power sources for most applications. These sources have slow dynamic response and should be protected against current impulses. These transients will be harmful to the membrane electrode assembly (MEA). Using only FC in this operational condition will degrade system performance and efficiency. Therefore the fuel cell system should be supplemented with an auxiliary power source. Controlling this hybrid system has important role in its overall performance. FC/Battery hybrid system is a complex and multivariable system and defining an exact mathematical model is complicated and time-consuming. On the other hand, the fuzzy controller doesn´t require a mathematical model of the system and provides a robust performance for both linear and nonlinear systems. In this study, fuzzy controller is applied for the purpose of power management. Fuel cell current and battery state of charge are controlled through applying switching pulses to the buck converter. So that the fuel cell efficiency is maintained at the optimum operating point. Voltage and current stress on battery and fuel cell is declined respectively. The proposed hybrid system is simulated via software. The simulation results have shown that the system has a satisfactory dynamic performance.