A 6-pole- 50 Hz- three-phase induction motor has rotor resistance and stand still reactance of 0-32 -phase and 3-2 -phase respectively- If starting torque of the motor is 40 N-m- then rotor voltage per phase at standstill is V-Answer upto 2 decimal places

Synchronous speed, ω_s=2P× 2π f=4×π× 506=104.72 rad/sec Starting torque, T_st=3ω_s.E^2_2r'_2(r'_2)^2+(x'_2)^2 40=3104.72×E^2_2× 0.32(0.32)^2+(3.2)^2 Rotor ...

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Standard VII

Physics

Electric Current and Electric Cell

A 6-pole, 50 ...

Question

A 6-pole, 50 Hz, three-phase induction motor has rotor resistance and stand still reactance of 0.32 $Ω$ /phase and 3.2 $Ω$ /phase respectively. If starting torque of the motor is 40 N-m, then rotor voltage per phase at standstill is _____V.(Answer upto 2 decimal places)
212.43

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Solution

The correct option is A 212.43
$Synchronous speed,$

$ω_{s} = \frac{2}{P} \times 2 π f = \frac{4 \times π \times 50}{6} = 104.72 r a d / s e c$

$Starting torque,$
$T_{s t} = \frac{3}{ω_{s}} . \frac{E_{2}^{2} r_{2}^{'}}{(r_{2}^{'})^{2} + (x_{2}^{'})^{2}}$

$40 = \frac{3}{104.72} \times \frac{E_{2}^{2} \times 0.32}{(0.32)^{2} + (3.2)^{2}}$

$Rotor voltage at standstill,$

$E_{2} = 212.43 V$

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A 6-pole, 50 Hz, three-phase induction motor has rotor resistance and stand still reactance of 0.32 Ω/phase and 3.2 Ω/phase respectively. If starting torque of the motor is 40 N-m, then rotor voltage per phase at standstill is _____V.(Answer upto 2 decimal places)212.43

The correct option is A 212.43Synchronous speed, ωs=2P×2πf=4×π×506=104.72 rad/sec Starting torque, Tst=3ωs.E22r′2(r′2)2+(x′2)2 40=3104.72×E22×0.32(0.32)2+(3.2)2 Rotor voltage at standstill, E2=212.43 V

A 6-pole, 50 Hz, three-phase induction motor has rotor resistance and stand still reactance of 0.32 $Ω$ /phase and 3.2 $Ω$ /phase respectively. If starting torque of the motor is 40 N-m, then rotor voltage per phase at standstill is _____V.(Answer upto 2 decimal places)
212.43