Abstract: New energy vehicle drive motors often operate under elevated-temperature conditions and non-uniform temperature fields during service. Their electromagnetic performance is closely related to the temperature dependence of the magnetic properties of the non-oriented silicon steel core material. To systematically investigate the influence of temperature variations on the magnetization behavior and iron loss characteristics of non-oriented silicon steel, three commercial grades with representative thicknesses of 0.20 mm, 0.35 mm, and 0.50 mm were selected for study. Based on the Epstein coil testing method, systematic experimental investigations were conducted across a broad temperature range from -70 ℃ to 150 ℃. Experimental results indicate that in the low magnetic field range, the magnetic permeability of the material increases with rising temperature. In contrast, in the high magnetic field range, it exhibits a decreasing trend. Meanwhile, the saturation magnetic flux density decreases slightly with increasing temperature, while the remanence and coercivity decline significantly. Regarding the characteristics of iron loss, at low frequencies, iron loss exhibits low sensitivity to temperature changes. However, at high frequencies, iron loss shows a pronounced decrease as temperature rises.

Key words: temperature; thickness; non-oriented silicon steel; magnetic properties