No. 1139
	Reduction Technology of Iron Loss in Stator Core of Synchronous Generator
	Investigating R&D Committee on Reduction Technology of Iron Loss in Stator Core of Synchronous Generator
	Keyword : Synchronous Generator, Stator, Core, Loss, Iron Loss
	This technical report is the result of investigation by "R&D committee on reduction technology of iron loss in stator core of synchronous generator". The survey object was focused on synchronous generators used for power systems. This report is based on the actual measures and latest findings in terms of material character of core, structure and manufacturing process of stator core, analysis method of iron loss, reliability and deterioration example, efficiency improvement by core replacement and so on. In chapter 2, material class and its histories of technical development are introduced for silicon steel plate, which is the main material of stator core. The method to measure the iron loss and the influence to the material character by manufacturing process such as core punching is also discussed. In chapter 3, method to reduce the iron loss is discussed in terms of stator core structure and manufacturing process of stator core. In chapter 4, the definition of iron loss in the standard, and the method to measure the iron loss is discussed. Besides, the survey result of iron loss from 235 synchronous machines made in Japan is also analyzed. In chapter 5, the traditional method to analyze the iron loss is introduced. And then the recent actual application to the electro magnetic field analysis is surveyed. In chapter 6, deterioration mechanism and diagnosis testing of stator core is introduced by using some actual failure experiences. In chapter 7, stator replacement result since 1950 is introduced, and concludes to our expectation for future technical developments.
	©2007. The Institute of Electrical Engineers of Japan