A Detailed Analysis of the Electromagnetic Phenomena Observed During the Flux-Decay Test

The paper analyses in detail the physical phenomena involved during the flux decay test used for the rotor time constant determination. The analysis has been performed on a 15 kW induction motor and the back e.m.f transient has been critically analysed during its evolution, finding a link between its time-by-time evolution and the physical phenomena that happen in both the stator and the rotor. In particular, the effects due to the lamination saturation, the stator and rotor leakage inductances and the stator iron losses have been associated to the transient evolution of the back e.m.f..