Assessment of Unbalance Factor in Line Currents During Fault Tolerant Operation of Five Phase Induction Motor-Drive System

This research article aims at assessment of unbalance factor in line currents during fault tolerant operation of five phase induction motor (FPIM) drive system. Multiphase machines have gained more popularity because of their appreciable features like fault tolerance, high torque density, reduced torque ripple and reliability. These features make them more suitable for industrial applications like electric vehicles, electric ship propulsion, aircrafts etc. Five phase induction motor is chosen because of its simple and robust nature. The stator of FPIM has three possible configurations, star, pentagon and pentagram. An open phase fault is modeled using back-EMF approach and an appropriate fault tolerant control technique (FTCT) is applied to compensate for the unbalance and distortion that occur due to open phase fault. The phase currents are free of distortion and unbalance after the applied strategy, nevertheless, line currents do not reflect the same. It is worth noting that the applied strategy can lessen distortion in line currents but unbalance still exists in line currents. The amount of unbalance present in the currents is accounted by unbalance factors. Here, unbalance current factors are calculated using the International Electrotechnical Commission (IEC) standard definition. The aforementioned strategy is simulated in MATLAB/Simulink environment and the simulation results are discussed assiduously.