Question

2. A) A three-phase, 415 V, 1460 rpm, 50 Hz, four-pole wound-rotor induction motor has the
following parameters per phase:
R1 = 0.25 ohms,
R'2 = 0.2 ohms
X1 = X'2 = 0.5 ohms, Xm = 30 ohms
The rotational losses are 1600 watts. With the rotor terminals short-circuited, find
(a)
(i) Starting current when started direct on full voltage.
(b)
(ii) Starting torque.
(i) Full-load slip
(ii) Full-load current.
(111) Ratio of starting current to full-load current.
(iv) Full-load power factor.
(v) Full-load torque.
(vi) Internal efficiency and motor efficiency at full load.
(c) (i) Slip at which maximum torque is developed.
(ii) Maximum torque developed.
(d) How much external resistance per phase should be connected in the rotor circuit so that
maximum torque occurs at start?​

Answer 1

Answer:

b.

c

d

a

a

Explanation:

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