Modelling and Hardware-in-Loop validation of a modified controller for intermittent operation of a standalone low voltage DC fuel cell system

Integration of renewable energy into conventional power system is increasing day by day which is motivating researchers to explore new forms of renewable energy and use them efficiently to fulfil generation demand gap. This paper deals with the design and operation of a standalone DC microgrid using fuel cell stack as a source of energy, coupled to a DC resistive load through a boost converter whose output voltage is controlled by a dual loop PI controller. The proposed system is designed to output a stable DC voltage of 48 V irrespective of the load variations and slow starting dynamics of fuel cell stack. Modifications made in controller configuration to facilitate the intermittent operation of the fuel cell is explained in detail. The modified controller configuration improves the reliability of the fuel cell system irrespective of the intermittent nature of the load. Time-domain analysis of the above said scenario is carried out using MATLAB/SIMULINK and is validated by a Hardware-in-Loop analysis in Virtex-6 FPGA using Xilinx system generator.