Assessment of Torque Density Improvement by Third Harmonic Injection in Five-Phase Induction Machine with Full Pitch Concentrated and Distributed Winding

This paper assess the improvement of torque density by third harmonic injection in five-phase induction machine with two types of windings, full pitch concentrated and distributed windings. A quasi-rectangular waveform of air-gap flux density involves a quasi-uniform distribution flux density which reduces saturations hence decreasing iron losses. Tow sequence planes d(1)_q(1) and d(3)_q(3), fundamental and third respectively, are used to modeling five-phase induction machines. The required air-gap flux waveform is quasi-rectangular when fundamental and third sequence direct axes are aligned. To ensure this alignment a suitable indirect flux oriented control is used. The assessment is conducted by simulation using MATLAB.