No. 1301
	Present Status and Future Trends of Special Synchronous Machines
	Investigating R&D Committee on Special Synchronous Machines
	Keyword : Rotating Machines, Motors, Generators, Synchronous Machines, Magnetic Gears
	In this technical report, information is widely collected about special synchronous machines which are not reported by the previous Investigating R&D Committees on Synchronous Machines, and it is classified and summarized. (1) The first topic is synchronous machines that have special structures: synchronous machines equipped with both permanent magnets and field windings, synchronous machines with circular solenoid coils (armature windings) surrounded by a multi-pole magnetic circuit, super low speed synchronous machines equipped with a reduction gear utilizing space harmonics, etc. (2) The second topic is doubly-fed AC machines that operate in a limited range around the synchronous speed; whether the doubly-fed AC machine is a synchronous machine or an induction machine is discussed, and its uses and practical examples are described. (3) The last topic is special-purpose synchronous machines: wind power generators using a hydraulic drive, short-circuit generators, flywheel motor-generators, frequency converter systems (M-G sets), metal rolling mills motors not presented in the technical report No. 935, magnetic gears, etc.
	©2007. The Institute of Electrical Engineers of Japan