Load-Tracking Performance of an Autonomous SOFC-Based Hybrid Power Generation/Energy Storage System.

This paper focuses on the load-tracking performance of an autonomous hybrid power generation/energy storage system (PG/ESS) with two solid-oxide fuel cells (SOFCs), a diesel engine generator (DEG), a battery ESS (BESS), two dc-dc converters, and a dc-ac inverter. The system can sustain PG to supply suddenly changed loads, one of which is an emergency load that must have uninterruptible power supply. This paper proposes a control scheme using the output dc current of the SOFC or the current magnitude of the ac load to modulate the hydrogen flow rate of the SOFC. The PG of the two SOFCs can be adequately coordinated with the generated power of the DEG, the stored/released energy of the BESS, and the output power of the dc- ac inverter to maintain both frequency and voltage of the connected loads at the desired values. Time-domain simulated results of the studied hybrid system under four studied cases are performed and analyzed to validate the good load-tracking characteristics of the proposed SOFC-based hybrid PG/ESS feeding time-varying loads. [ABSTRACT FROM AUTHOR]