The design of low-speed variable-reluctance generators

This paper presents a design methodology appropriate for low-speed variable-reluctance generators (VRGs). This work is motivated by the application of VRGs to direct-drive wind turbines and other renewable energy systems. In direct-drive systems significant simplifications result from the elimination of the gear box which has traditionally been used to interface a slowly rotating shaft with the generator shaft. The running example considered is the design of a generator which is to support 20 kW at a rotor speed of 120 rpm.