Pentagon Connected Five-Phase Induction Machine Working under One-Phase Fault

The presented paper deals with the five-phase induction motor (IM) having pentagon connected stator winding, which is working under one phase supply failure. Computation of the motor electromagnetic quantities are made using the space vector theory in the complex plane. Analysis is done assuming, the motor is supplied by a pulse width modulation (PWM) controlled inverter with sufficiently high modulation frequency. Only the first stator voltage harmonics is taken into consideration. On the base of measured IM parameters, trajectories of stator and rotor current space vectors were investigated. On their basis, the motor electromagnetic torque ripple waveform for failure supply mode is derived. Finally a possibility to reduce torque ripple in failure state is shown.