On-line observer modification of a six-phase induction generator in faulted mode

Energy production or critical applications need fault tolerant operation. Six-phase induction machine (SC6PIG) increases the reliability by allowing the loss of up to 3 phases. Associated with a relevant novel control able to adapt itself to the new configuration, operation can keep on under fault. A novel strategy of control is here proposed with sensorless control. This strategy nonetheless focus on robust method but on switching between configurations with standard observer and controller. A set up of the new configuration is made at switching to minimize transient. The experimental results, shown in healthy and faulty modes including the online switching between the sensorless control system from healthy to faulty operation, assess the validity of the proposed strategy.

I. Introduction

Democratization of power electronics makes possible the uses of multiphase machine. These machines have the big advantage to increase the reliability of system [1]. Critical systems provider as aeronautic or application designer with hard maintenance are more and more involved in research [2]. Thus, different types of permanent magnet and induction machines with five, six (symmetrical and asymmetrical) and seven phases have been proposed in the literature of multiphase machines [3]–[5]. Among all types of multiphase machines, one of the most popular is the symmetrical squirrel cage six-phase induction machine (SC6PIM) both for motor [4]–[5], [6]– [7] and for generator operating modes [8].