Hysteresis and Eddy-Current Losses in Electrical Steel Utilising Edge Degradation Due to Cutting Effects

Abstract

Cutting of electrical steel sheets typically deteriorates the permeability and increases the iron loss close to the cutting edges. We estimated iron losses in the cross‐section of electrical steel sheets by numerically solving the 1‐D and 2‐D eddy‐current distributions while accounting for static magnetic behaviour with a hysteresis model. The magnetization curves in the cross‐section are defined using a continuous local material model, making them dependent on the distance from the cut edge by a degradation profile. Damaged and undamaged hysteresis loops were identified by measurements of different wide strips of M400‐50A steel sheets. The eddy‐current distributions were solved when the strips of different widths were excited with sinusoidal average flux densities at different frequencies. It was found that the cutting degradation also affects the eddy‐current loss particularly around 1.0 T. The exact shape of the degradation profile was found to be less significant while the increase of excess losses is significant for the overall loss estimation.