Dependence of Iron Loss in Electrical Steel Sheets on Ambient Temperature

To optimize the performance of electrical steel sheets used in devices such as motors and transformers, it is essential to accurately evaluate their magnetic properties under standardized conditions. Standardized methods, including the Single Sheet Test (JIS C 2556) and the Epstein Test (JIS C 2550-1), require high measurement reproducibility and specify an ambient temperature of (23 ± 5) °C. This study investigates the dependence of iron loss in electrical steel sheets on ambient temperature within (23 ± 5) °C. The results indicate that iron loss is influenced by ambient temperature, exhibiting a negative temperature coefficient. This coefficient depends on the steel grade. These findings clarify the temperature sensitivity and reliability of magnetic loss measurements under standardized conditions, and contribute to more accurate magnetic evaluation.