Dynamic Modeling of a Hybrid Energy Source Combined of PEM Fuel Cell and Ultracapacitor

Fuel cell technologies are expected to become a suitable substitution for conventional power generators and grid utility for residential applications, as they are more efficient and environmentally friendly in comparison with other conventional power generators. However, in order to provide power demand of a residential load, it may be required to over design fuel cell power module which is not economically advisable. Furthermore, due to the sluggish dynamic response of fuel cell in transient events, there will be load following problem. In such cases, it is recommended to combine fuel cell with other electrical energy storage devices to satisfy sustained load demand and transient events. While batteries have low power densities and limited lifetime in highly cyclic application, ultracapacitors can be used. An ultracapacitor (UC) bank can supply a large burst of power but cannot store much energy. By operating the FC and UC in parallel, both steady state and peak power demands can be satisfied. In this paper an improved dynamic model of Nexttrade PEM fuel cell power module is developed; in addition, it is used to design a hybrid energy source consisting of FC and UC for residential applications. The proposed dynamic model is presented in Matlab/Simulinkreg and SimPowerSystemsreg environment.