Method for Determining the Optimal Thickness of Sheets of Magnetic Circuits of Electrical Machines by a Wattmeter Method

The problem of reducing magnetic losses (no-load losses) in the steel of magnetic circuits of electrical machines is studied. The determination of the optimum thickness of steel sheets of magnetic circuits in electrical machinery is investigated. The optimization criterion is minimum power losses in the steel. The magnetic power losses in contemporary electrical machinery and apparatus are analyzed as a function of the thickness of the sheets of electrical steel. A method is proposed for determining the optimum thickness of steel sheets in the magnetic circuit of an electrical machine based on a wattmeter technique. During an experiment on two identical magnetic circuits made of different thicknesses of sheet steel, the losses in the steel were measured at two magnetic reversal frequencies and the optimum thickness of the sheets was calculated. It was shown that the proposed formula for calculating the sheet thickness holds for both isotropic and anisotropic steel. The proposed method is applicable to transformers, as well as to electric motors and generators.