Jf. Moreno et al., Realisation of tests to determine the parameters of the thermal model of an induction machine, IEE P-EL PO, 148(5), 2001, pp. 393-397
Tests are described to determine the parameters and coefficients of a therm
al model. which allows one to estimate the stator and rotor temperatures in
a three-phase induction machine, during operation. The model is obtained b
y analysing the power losses and the heat transmission inside the motor (co
nsidering it in two parts: stator and rotor) and with the environment. Two
differential equations are deduced. which reflect. at each instant. the bal
ance among the power losses. the evacuated heat and the stored heat in the
motor. The study is carried out for a three-phase motor with a short-circui
ted rotor in a squirrel cage with nominal values: 1 kW. 380 V and 50 hz. Fr
om the stator and rotor temperatures provided by the thermal model, the upd
ated values of the electrical resistances of the machine are obtained in re
al time during its operation.