please solve all question parts in order to four decimal places thanks in advance !! A 400 V, 50 Hz, 6-pole, 940 rpm, st

[answerhappygod]

please solve all question parts in order to four decimal
places
thanks in advance !!
A 400 V, 50 Hz, 6-pole, 940 rpm, star connected induction
motor has the following parameters: stator and rotor resistances
are 1.35 Ω each, and stator and rotor leakage reactance are
2 Ω each (magnetising reactance can be neglected). The
motor is controlled by simultaneous stator voltage and frequency
variation. Voltage boost is not used and the motor is controlled
using V/f = constant law. The motor is supplied from a three-phase
voltage source inverter.
a) The motor operates at 35 Hz. Calculate the
ratio of the maximum torque at this frequency with respect to the
one at rated frequency, for both motoring and generation.
For the motoring case the
ratio is:
For the generation case the
ratio is:
b) For the same 35 Hz operating frequency,
calculate ratio of the starting current at this frequency with
respect to the starting current at rated frequency.
Starting
current ratio is:
c) Assume that the voltage boost of 50 V (phase
voltage) is used. Calculate new value of the phase voltage that
would be applied in this case for the operating frequency of 35 Hz.
Repeat part b) with this new voltage applied.
Starting current ratio: