WHY 5 PHASE OVER 3 PHASE
Multiphase machine has a greater fault tolerance compared to
its 3 phase counterparts if one phase of the 3 phase machine
becomes open circuited so single phasing occurs . It may
continue to run, but will require external means for starting
and must be massively derated. If one phase of multiphase
machine becomes open circuited it will self start and will run
with only minimal derating
Another reason for multiphase variable speed drive is the
possibility of reducing the required rating of the power
electronics components for a given output power of the motor,
when compared to a 3 phase motor.