Hybrid simulation of fuel cell power conversion systems

Simulation techniques and results are presented for hybrid computer studies of line-commutated and self-commutated three phase bridge inverters. The line-commutated bridge system included constant extinction angle control of the inverter, power regulation of the DC source, and power factor correction capacitors. Simulation of this system was performed in real-time which allowed testing of prototype control hardware. The self-commutated system consists of three bridges operating in a phased sequence which permits elimination of harmonics by cancellation. System performance is evaluated with the inverters operating into a three phase load, part of which is supplied by the utility system. The paper discusses the computational techniques used in simulating systems of this type, including the role of the digital and analog computers in each study. This work supports the conclusion that hybrid simulation is a valuable tool for analysis and evaluation of power conversion systems which contain current switching devices.