Indirect Field Oriented Control of an Unbalanced Nine-Phase Induction Motor due to Open Phases

摘要

Multiphase machines have several advantages when compared to three-phase machines. Their inherently higher reliability makes them attractive in several applications. For instance, the nine-phase motor can operate with up to six open phases in its stator. However, in order to allow the multiphase machine to work magnetically balanced even in open phase conditions, an adequate current control can be employed. To develop this control scheme, it is necessary a synchronous-frame modeling of a nine-phase induction motor (9PIM) under open phase faults, which is developed here. Using it, indirect field oriented control is derived, still using proportional controllers in the current loops. This is possible due to the use of an appropriate voltage decoupling considering the fault condition. Hence, the unbalanced multiphase induction motor can be controlled very similarly as a balanced one, additionally resulting in torque ripple minimization. Simulation results show the success of the proposed control scheme.