Six-Phase Induction Machine Model for Electrical Fault Simulation Using the Circuit-Oriented Method

The aim of this paper is to present a six-phase induction machine (6PIM) model based on the so-called circuit-oriented approach suitable for simulation of electrical faults on both stator and rotor sides. This specific model has been developed by using only resistances, inductances, and controlled voltage sources. The coupling effects between both the stator and the rotor have been taken into account by the computation of stator–rotor mutual inductances. The model has been developed under the MATLAB/Simulink environment in order to have a universal tool that is easy to use with any control techniques. With this model, it is possible to simulate any type of electrical faults during the motion by closing or opening corresponding switches. The performances of the model have been validated by comparing simulation and experimental results of a 90-W 14-V 50-Hz two-pole 6PIM operating with different levels of load torque in healthy and faulty modes. Furthermore, this model has been associated to a fault-tolerant speed control method in phase opening occurrences in order to test the model accuracy.

I. Introduction

Three-phase induction machines are extensively used in many industrial applications for their simplicity, robustness, and reliability. Nevertheless, for specific fields where high reliability is required, such as automotive, aerospace, military, and nuclear, it appears that using classical three-phase induction machines is no more suitable since loss of one or more phases induces the unviability of the whole system. One solution is to increase the number of phases on machine and converter sides in such a way as to obtain a multiphase system [1]. This configuration (with more than three phases on the stator and the inverter) presents many advantages, such as high power-handling capability by dividing the required power between phases, reduced torque pulsations, reduced stator copper losses [2], and reduced rotor harmonic currents [3], but, above all, higher reliability.