Control strategy of 600kW E-BOP for molten carbonate fuel cell generation system

An electrical balance of plant(E-BOP) of a 600 kW molten carbonate fuel cell (MCFC) has to transit from grid-connected(GC) mode to grid-independent(GI) mode when a grid is in a fault conditions. A minimum transition time is limited by four cycle for a 600 kW MCFC to ride through a grid fault. In this paper, we propose a control algorithm of a 600 kW E-BOP for a MCFC system. The E-BOP has three operation modes, i.e., GC mode, GI mode, and grid-synchronized(GS) mode. The E-BOP controls output currents in a GC mode and regulates output voltages in GI or GS mode. GS mode is defined as an interface between GC mode and GI mode to make a mode transition smooth, i.e., limitation of inrush currents, regulation of output voltages within ANSI standard. Simulations and experiments carried out to verify the effectiveness of the proposed control algorithm.