Use of field harmonics in multiphase induction motor drives for on-line parameter estimation

Multiphase drives are very promising in high power applications, because the total power can be split among several phases. In addition, the higher number of phases allows defining fault tolerant strategies that improve the reliability of the drive. An interesting feature of multiphase machine is the capability of controlling high order space harmonics of the magnetic field, in addition to the fundamental one. In this paper, it is shown how this characteristic can be used to monitor the state of the machine or to estimate the stator parameters that are necessary for field-oriented control.