Mini gas turbines and high speed generators a preferred choice for serving large commercial customers and microgrids. I. Generating system

This two part series of papers for the first time describes a mini gas turbine generating system serving a microgrid. Part I is devoted to the mini gas turbine generating system and Part II describes the microgrid. A 250 kW to 500 kW gas turbine and high speed axial flux generator is ideally suited for providing the electric power, heating, and cooling (CCHP) needs of large commercial and light industrial customers as well as serving aggregated high load factor commercial and residential customers. It is difficult for small gas turbine generators less than 100 kW to be competitive, because of the high relative cost of interconnection, installation, and system protection requirements; and the high investment cost and low efficiency < 28% without CCHP applications. Units larger than 250 kW are the preferred choice, because of lower cost per kW of investment, lower relative interconnection cost, and higher efficiency > 30% without CCHP. The mini gas turbine generating system and microgrid introduced in this series of papers is competitive with most electric utility rates, and possesses improved performance characteristics over central station generation and T & D power systems; and microturbine generation.