Dynamic models for micro-turbines and fuel cells

Distributed resources (DR) include a variety of energy sources, such as micro-turbines, photovoltaics, fuel cells, and storage devices, with capacities in the 1 kW to 10 MW range. Deployment of DR on distribution networks could potentially increase their reliability and lower the cost of power delivery by placing energy sources nearer to the demand centers. By providing a way to by-pass conventional power delivery systems, DR could also offer additional supply flexibility. The trends in technology points toward smallness, under the 500 kW level. An example are the small gas fired micro-turbines in the 25-100 kW range that can be mass produced at low cost. Fuel cells are also well suited for distributed generation applications. There are two basic classes of micro-source systems; one is a DC source, such as fuel cells, photovoltaics, and battery storage, the other is a high frequency AC source such as the micro-turbine which needs to be rectified. Power electronic interfaces introduces new control issues and new possibilities. This paper discusses micro-turbine and fuel cell models, and the instanteous power issue. An inverter model is also presented.