Electrical coil thermal parameters determination by express experimental data processing

Investigation results are presented for electrical coil thermal parameters prediction. The coil is EI transformer type construction. The time constant and steady state temperature rise are predicted, based only on limited number experimental data, using directly Least Square Method (LSM) and recommendations in [1]. The equivalent values for the coil heat capacity and thermal resistance are also calculated, which opens a way to investigate various transient processes by computer simulation. Comparative results for a separate coil and iron-cored one are presented, analyzed and discussed.