x

Stator Voltage Control of three phase induction motor

Stator Voltage Control of three phase induction motor

135 views

asked Aug 9, 2017 by anonymous

2 Answers

Answer :

Stator Voltage Control of three phase induction motor

By stator voltage control :

•We have,

•Torque is directly proportional to stator voltage square.

•The torque is directly proportional to speed so if torque will decrease speed also decrease and if torque will increase speed also increase.

•So we can control speed of three phase induction motor by varying stator voltage.

•This method is suitable for application where load torque decreases with speed.

•This method is sometimes used for small motor fans.

•This method is very easy and cheap but still use rarely.

•Because by decreasing the voltage torque will reduce.

•But to maintain power (P=VI) this will increase current in motor which will heat the motor which is not good it causes losses.

•Also the torque is proportional to square of voltage so large voltage change is required for changing torque.

answered Aug 9, 2017 by anonymous

Answer :

Stator Voltage Control of three phase induction motor

answered Aug 25, 2017 by anonymous

Please log in or register to answer this question.

Related Questions

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then (A) the flux is constant (B) the flux first decreases and then increases in ... increases and decreases in the opposite direction with the same magnitude (D) current flows through the rotor
Last Answer : In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then the flux first decreases and then increases in the same direction

95 views 1 answer

asked Apr 28, 2018 by anonymous

Explain speed control method of 3 phase induction motor by the following methods: (1) Pole changing (2) Rotor resistance control (3) Stator voltage

Explain speed control method of 3 phase induction motor by the following methods: (1) Pole changing (2) Rotor resistance control (3) Stator voltage
Last Answer : 1) Pole Changing Method: Synchronous speed is given by, From the above equation of synchronous speed, it can be seen that synchronous speed (and hence, running speed) can ... in voltage and consequently the speed decreases and vice versa. Ultimately speed depends on the supply voltage.

999 views 1 answer

asked Jul 20, 2019 by anonymous

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque (1) Decreases (2) Increases (3) Remains constant (4) None of the above
Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases

239 views 1 answer

asked May 1, 2018 by anonymous

In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage supply to the stator windings C. laminated steel core and aluminum conductors in the rotor D. interaction of the magnetic field caused by the induced current in the squirrel-cage bars with the magnetic field of the stator

In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator
Last Answer : Answer: B

16 views 1 answer

asked Jan 4 by itszee

The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. changing the RPM of the rotor flux C. changing the phase sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity
Last Answer : Answer: A

13 views 1 answer

asked Jan 4 by itszee

Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to

Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be
Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m

436 views 1 answer

asked Apr 29, 2018 by anonymous

speed control methods of three phase induction motor?

speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor

376 views 2 answers

asked Aug 9, 2017 by anonymous

The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip increases, rotor reactance decreases. B. The pullout point on the torque curve is about seven times the normal full load torque value. C. At stand still, stator current is 150% of normal. D. If the motor is loaded to the point where 40% slip has resulted, it will stall.

The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip ... D. If the motor is loaded to the point where 40% slip has resulted, it will stall.
Last Answer : Answer: D

9 views 1 answer

asked Jan 4 by itszee

A three-phase, squirrel cage, induction motor will run hot due to a/an ______________. A. improper brush position B. reversed commutating pole C. shorted stator D. high power factor

A three-phase, squirrel cage, induction motor will run hot due to a/an ______________. A. improper brush position B. reversed commutating pole C. shorted stator D. high power factor
Last Answer : Answer: C

7 views 1 answer

asked Jan 4 by itszee

A three-phase, squirrel cage, induction motor will run hot due to _____________. A. open stator coils B. high power factor C. dirty or corroded slip rings D. reversed commutating poles

A three-phase, squirrel cage, induction motor will run hot due to _____________. A. open stator coils B. high power factor C. dirty or corroded slip rings D. reversed commutating poles
Last Answer : Answer: A

8 views 1 answer

asked Jan 4 by itszee

The rotation of a three-phase induction motor can be reversed by _____________. A. interchanging any two of the three line leads to the stator B. disconnecting one of the three line leads to the stator C. switching the shunt field coil leads D. permanently disconnecting any two of the three line leads to the stator

The rotation of a three-phase induction motor can be reversed by _____________. A. interchanging any two of the three line leads to the stator B. disconnecting one of the three line leads to the ... the shunt field coil leads D. permanently disconnecting any two of the three line leads to the stator
Last Answer : Answer: A

4 views 1 answer

asked Jan 4 by itszee

The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding

The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding
Last Answer : Answer: B

8 views 1 answer

asked Jan 4 by itszee

A 415v, 4 pole three phase induction motor operates from supply whose frequency is 50Hz, find the stator field

Basic electrical engineering

13 views 0 answers

asked May 17, 2021 by naga surendra

A three phase slip ring induction motor is fed from the rotor side with stator winding short circuited stator is:

A three phase slip ring induction motor is fed from the rotor side with stator winding short circuited stator is: (1) Slip frequency (2) Supply frequency (3) Frequency corresponding to rotor speed (4) Zero
Last Answer : A three phase slip ring induction motor is fed from the rotor side with stator winding short circuited stator is: Slip frequency

2.2k views 1 answer

asked May 22, 2018 by anonymous

in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure:

in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure:
Last Answer : in a three-phase induction motor, the rotor field runs at the following speed with respect to the stator structure: At synchronous speed in the direction of stator field

438 views 1 answer

asked May 22, 2018 by anonymous

If the stator winding of a three-phase induction motor is delta connected, the rotor winding

If the stator winding of a three-phase induction motor is delta connected, the rotor winding (a) should be delta connected (b) should be star connected (c) should not be delta connected (d) may be delta or star connected

128 views 0 answers

asked Apr 10, 2018 by anonymous

In the illustrated device, the part labeled '1A' _________. EL-0001 A. are start and run windings for a single phase shaded pole induction motor B. is the stator for a polyphase induction motor C. is the armature for a squirrel cage rotor motor D. are direct current shunt field windings for a universal motor

In the illustrated device, the part labeled '1A' _________. EL-0001 A. are start and run windings for a single phase shaded pole induction motor B. is the stator for a polyphase induction ... armature for a squirrel cage rotor motor D. are direct current shunt field windings for a universal motor
Last Answer : Answer: B

3 views 1 answer

asked Jan 4 by itszee

The stator mmf and rotor mmf of a 3-phase induction motor

The stator mmf and rotor mmf of a 3-phase induction motor (A) are equal (B) rotate with slip speed (C) are opposite but rotate with synchronous speed (D) rotate with the same rotor speed
Last Answer : a

284 views 1 answer

asked Jun 4, 2018 by anonymous

A 3-phase induction motor under locked rotor condition and with stator supply, induces

A 3-phase induction motor under locked rotor condition and with stator supply, induces (A) small voltage at slip frequency (B) large voltage at rotor frequency (C) zero voltage at zero frequency (D) large voltage at slip frequency
Last Answer : A 3-phase induction motor under locked rotor condition and with stator supply, induces (A) small voltage at slip frequency (B) large voltage at rotor frequency (C) zero voltage at zero frequency (D) large voltage at slip frequency

325 views 1 answer

asked Apr 25, 2018 by anonymous

A 3-phase, 50 Hz, 500 V induction motor develops 20 hp at slip of 5%. Mechanical losses are 1 hp, and stator..

A 3-phase, 50 Hz, 500 V induction motor develops 20 hp at slip of 5%. Mechanical losses are 1 hp, and stator loss is 1 kW. The efficiency will be (a) 95.3% (b) 90.5% (c) 91.3% (d) 85.3%

212 views 0 answers

asked Apr 10, 2018 by anonymous

The stator of a 3 phase, 10 pole induction motor possesses 120 slots. If a lap winding is used, calculate the...

The stator of a 3 phase, 10 pole induction motor possesses 120 slots. If a lap winding is used, calculate the coil pitch, if the coil width extends from slot 1 to slot 11. (A) 72.12% (B) 83.30% (C) 12% (D) 42%

171 views 0 answers

asked Apr 5, 2018 by anonymous

The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit

The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit
Last Answer : Answer: A

5 views 1 answer

asked Jan 4 by itszee

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging.

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the ... the motor will be (A) 23.06 kW (B) 24.11 kW (C) 25.01 kW (D) 26.21 kW
Last Answer : A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the core losses are 1200 W. The air-gap power of the motor will be 25.01 kW

363 views 1 answer

asked May 17, 2018 by anonymous

The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is

The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is
Last Answer : The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is 4 percent

365 views 1 answer

asked Apr 29, 2018 by anonymous

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for
Last Answer : A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for 4 poles

311 views 1 answer

asked Apr 29, 2018 by anonymous

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW.

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is (A) 5.06 kW (B) 0.3 kW (C) 100 kW (D) 83.33 kW
Last Answer : An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is 83.33 kW

180 views 1 answer

asked Apr 28, 2018 by anonymous

The rotor winding of a three phase wound rotor induction motor is equipped with a three phase diode...

The rotor winding of a three phase wound rotor induction motor is equipped with a three phase diode rectifier connected to the slip rings and rectifier output is connected with chopper drive. Compared to ... B) Maintains the motor rating as such C) Derates the motor D) None of the above

90 views 0 answers

asked Apr 9, 2018 by anonymous

How is a three phase cage induction motor self starting?

How is a three phase cage induction motor self starting?
Last Answer : Any type of induction motor is self starting. Because the reason for torqe production require two flux displaced by some angle theta.If theta is constant with time then torqe will be constant;if ... torqe also pulsating. In induction motor this angle theta is not pulsating.so it is self starting

160 views 1 answer

asked Mar 17, 2018 by anonymous

What is mean by plugging in three phase induction motor?

What is mean by plugging in three phase induction motor?
Last Answer : Plugging in three-phase induction motor means interchanging of any two phases of a stator for quick stopping.

158 views 1 answer

asked Mar 3, 2018 by anonymous

Types of three phase induction motor rotor

Types of three phase induction motor rotor
Last Answer : Types of three phase induction motor rotorSquirrel cage rotor : There are two types of three phase induction motor rotor one is squirrel cage rotor and second is wound rotor. About 80 to ... control of three phase induction motor via rotor resistance control method is possible with this rotor.

148 views 1 answer

asked Aug 9, 2017 by anonymous

A degree of control over the speed of a slip ring induction motor can be obtained by _____________. A. adjusting governor linkage B. changing the number of phases to the motor C. inserting resistance into the stator circuit D. inserting resistance into the rotor circuit

A degree of control over the speed of a slip ring induction motor can be obtained by _____________. A. adjusting governor linkage B. changing the number of phases to the motor C. inserting resistance into the stator circuit D. inserting resistance into the rotor circuit
Last Answer : Answer: D

4 views 1 answer

asked Jan 4 by itszee

Split phase induction motor

Split phase induction motor
Last Answer : Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.

233 views 1 answer

asked Sep 20, 2018 by anonymous

The starting torque of a V/f controlled inverter-fed 3-phase induction motor operating at 25 Hz as compared

The starting torque of a V/f controlled inverter-fed 3-phase induction motor operating at 25 Hz as compared with the same motor operating at 50 Hz is (A) more (B) double (C) equal (D) less

62 views 0 answers

asked Jun 4, 2018 by anonymous

In slip-energy recovery scheme of converter-fed 3-phase induction motor, super synchronous speeds are

In slip-energy recovery scheme of converter-fed 3-phase induction motor, super synchronous speeds are possible by (A) injecting voltage into the stator (B) injecting voltage into the rotor (C) extracting voltage from the stator (D) extracting voltage from the rotor.

70 views 0 answers

asked Jun 4, 2018 by anonymous

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A
Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A

458 views 1 answer

asked May 17, 2018 by anonymous

In a split-phase induction motor, the resistance/reactance ratios of windings are such that

In a split-phase induction motor, the resistance/reactance ratios of windings are such that (A) current in the auxiliary winding leads the current in the main winding (B) current in the ... (C) both windings develop the same starting torque (D) both windings develop high starting current
Last Answer : In a split-phase induction motor, the resistance/reactance ratios of windings are such that current in the auxiliary winding leads the current in the main winding

107 views 1 answer

asked Apr 28, 2018 by anonymous

A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor

A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor rotates at a speed of ________ rpm with respect to stator field. (A) 1500 (B) 0 (C) 1440 (D) 60
Last Answer : 0

2.1k views 2 answers

asked Apr 28, 2018 by anonymous

The torque developed by any 3-phase induction motor at 0.8 p.u. slip is

The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down
Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque

3.1k views 1 answer

asked Apr 28, 2018 by anonymous

In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an

In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is (A) 0.2 Ω (B) 0.3 Ω (C) 0.4 Ω (D) 0.5 Ω
Last Answer : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is 0.3 Ω

169 views 1 answer

asked Apr 28, 2018 by anonymous

After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on?

Last Answer : Reason is kinetic energy

290 views 2 answers

asked Mar 20, 2018 by anonymous

If starting winding of a single-phase induction motor is left in the circuit, it will?

Last Answer : If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.

236 views 1 answer

asked Mar 20, 2018 by anonymous

If a single phase induction motor runs slower than normal, the most likely defect is?

Last Answer : If a single phase induction motor runs slower than normal, the most likely defect is worn bearings.

170 views 1 answer

asked Mar 20, 2018 by anonymous

How does a single phase induction motor work?

How does a single phase induction motor work?
Last Answer : As we know that single phase induction is not self started because for self started we require atleast two revolving field but single phase induction motor has only one. So we provide extra ... 1phase IM classified as split phase IM, capacitor start capacitor run, capacitor start induction run.

124 views 1 answer

asked Mar 17, 2018 by anonymous

explain the working of single phase induction motor.

explain the working of single phase induction motor.
Last Answer : Stator has two winding namely main winding and auxiliary winding.when single phase ac supply is given to the motor,its produces alternating field.this field cut by a cage rotor.so some emf ... due to this emf,rotor flux produced.the interaction between two fluxes produce torque.so rotor rotates.

188 views 1 answer

asked Oct 24, 2017 by anonymous

which single phase induction motor has highest starting torque?

Last Answer : Capacitor start motor has high torque in starting

137 views 1 answer

asked Sep 13, 2017 by anonymous

Single Phase Induction Motor

Single Phase Induction Motor
Last Answer : Single Phase Induction Motor Single phase induction motor is mostly used in home, office, shop and many single phase appliances like pumps, ... torque and silent operation. It is uses where silent operation is required.

528 views 1 answer

asked Aug 9, 2017 by anonymous

A change of 4% in the supply voltage to an induction motor will produce a change of approximately

A change of 4% in the supply voltage to an induction motor will produce a change of approximately
Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

492 views 1 answer

asked May 8, 2018 by anonymous

In a Synchronous motor, the magnitude of stator back e.m.f (Eb) depends on

In a Synchronous motor, the magnitude of stator back e.m.f (Eb) depends on
Last Answer : In a Synchronous motor, the magnitude of stator back e.m.f (Eb) depends on DC excitation only

174 views 1 answer

asked May 15, 2018 by anonymous

The purpose of stator winding in the compensated repulsion motor is to?

Last Answer : The purpose of stator winding in the compensated repulsion motor is to improve power factor and provide better speed regulation.

111 views 1 answer

asked Mar 20, 2018 by anonymous

A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with

A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with 60o phase spread. Coil span is 7 short pitches. Number of slots in which top and bottom layers belong to different phases is (A) 24 (B) 18 (C) 12 (D) 0
Last Answer : A 4-pole, 3-phase, double-layer winding is housed in a 36-slot stator for an ac machine with 60o phase spread. Coil span is 7 short pitches. Number of slots in which top and bottom layers belong to different phases is 24

1.7k views 1 answer

asked May 18, 2018 by anonymous

Show More ⇦ Previous Next ⇨