Solid‐Oxide Fuel Cell and Its Control

For reliable operation, battery energy storage system (BESS) with renewable energy source (RES), such as a wind and solar-based distribution system generally gives satisfactory performance when connected to AC grid. However, large charging time and requirement of one additional unit for recharging of batteries, and the intermittent nature of RESs are the main challenges associated with this system. These problems can be solved with non-intermittent fuel cells that do not require recharging. There are various kinds of fuel cells and among them the solid oxide fuel cell (SOFC) is the most efficient on the distribution system. However, SOFC is a multiple-input-multiple-output and non-linear device. There exists a strong coupling between its control variables, and when it is connected to the AC grid, the control problem becomes severe, due to the addition of variables associated with inverter and its control circuitry. Therefore, firstly, the characteristics of SOFC have been studied, by linearising it in the MATLAB/SIMULINK environment. Finally, after selecting the appropriate control variable pairing, a systematic development of a coordinated control scheme has been accomplished for improving the life of SOFC by keeping its associated variables into the feasible operating limits. Comparison of simulation results shows the superior performance of proposed scheme in contrast to the already existing control scheme. With this proposed scheme, it is possible to keep the grid voltage and grid frequency at one per unit. Further, this chapter also highlights the worldwide recent trend of fuel cells with their techno-economic aspects and market policies.