A 3-0, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill betweenslip-rings on open circuit. Calculate the current and power factor in each phase of the rotor windingsat standstill when joined to a star-connected circuit, each limb of which has a resistance of 10 Q andan inductance of 0.03 H. The resistance per phase of the rotor windings is 0.2 Q and inductance0.03 H. Calculate also the current and power factor in each rotor phase when the rings are short-circuited and the motor is running with a slip of 4 per cent.[13.6 A, 0.48; 27.0 A, 0.47] (London University)A 4-pole, 50-Hz, 3-phase induction motor has a slip-ring rotor with a resistance and standstill reactanceof 0.04 2 and 0.2 2 per phase respectively. Find the amount of resistance to be inserted in each rotorphase to obtain full-load torque at starting. What will be the approximate power factor in the rotor atthis instant ? The slip at full-load is 3 per cent.[0.084 2, 0.516 p.f.] (London University)A 3-o induction motor has a synchronous speed of 250 r.p.m. and 4 per cent slip at full-load. The

Since you have asked multiple question, we will solve the first question for you. If youwant any…

A 3-0, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between slip-rings on open circuit. Calculate the current and power factor in each phase of the rotor windings at standstill when joined to a star-connected circuit, each limb of which has a resistance of 10 Q and an inductance of 0.03 H. The resistance per phase of the rotor windings is 0.2 Q and inductance 0.03 H. Calculate also the current and power factor in each rotor phase when the rings are short- circuited and the motor is running with a slip of 4 per cent.

A 3-0, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between slip-rings on open circuit. Calculate the current and power factor in each phase of the rotor windings at standstill when joined to a star-connected circuit, each limb of which has a resistance of 10 Q and an inductance of 0.03 H. The resistance per phase of the rotor windings is 0.2 Q and inductance 0.03 H. Calculate also the current and power factor in each rotor phase when the rings are short- circuited and the motor is running with a slip of 4 per cent.

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter39: Synchronous Motor Operation

Section: Chapter Questions

Problem 14SQ: Induction motors and welding transformers require magnetizing current, which causes a. lagging power...

See similar textbooks

Similar questions

3. What are the various losses in an induction motor? On whatfactors do they depend?
The rotor of a 3-phase, 60 Hz, 4-pole induction motor takes 118 kW at 3Hz. The motor has stator copped loss of 2.95 kW, a mechanical loss of 2kW and a stator core loss of 1.7 kW. Solve for the motor efficiency
1. The operation of Commutator in DC Motor is * O a) to convert dc to ac O b) to convert ac to dc O c) to convert fixed dc to variable dc O reverse the current direction in the rotating windings each half turn
What are the similarities and dissimilarities of a 3-phase induction motor and a transformer?
If two 3-phase induction machines are mechanically coupled with each other. The two machines are supplied by 50 Hz and 60 Hz, respectively. the speed of the combination of both machines will be:
In DC generators, lap winding is suitable for ) high voltage, high current O low voltage, high current O high voltage, low current O ) low voltage, low curren O
Rotor resistance of a three-phase induction motor is 0.080 per phase. Maximum torque is available at the slip of 12%. Calculate the equivalent load resistance, load voltage and load current at this slip. Gross output power is 9 kW. zwoll E2 1₂ INSTR₂=0.08001 od X₂ boobs Yo not www YOUR voor R₁ R₂(1/S-1) constaies sidsiuv od lliw sad jedanss
A DC generator with 8 pole, duplex lap winding excited with a flux of 3mWb/ pole. The number of parallel path in the winding is A 12 B 8 C 16 D 4
The frequency of rotor current in an induction motor is slip times the frequency of stator current. slip times the frequency of supply, One by slip times the frequency of stator current. One by slip times the frequency of supply
how does the rotor of a 3-phase induction motor get power a- through brushes and commutador segments b- through brushes and slip ring c- indution from the stator d- none of the above
A four-pole, wave-wound generator has 220 coils of 10 turns each. The resistance of each turn is 0.02 2. Find the resistance of the armature winding.
1. Write down some advantages and disadvantages of different connections of three-phase transformers . (Write mainly for delta-delta, wye-wye, wye-delta and delta-wye)2. What is skew effect? Why is it important for the rotor of an induction motor?