112 views

1 Answer

Answer :

Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.

Like 0 like

Please log in or register to answer this question.

Related questions

176 views

Description : The synchronous motor which works on leading power factor and does not drive any mechanical load is called?

Last Answer : The synchronous motor which works on leading power factor and does not drive any mechanical load is called synchronous condenser.

1 answer
129 views

Description : If we change the excitation of synchronous machine will it affect on power factor?

Last Answer : Yes, If we change the excitation of synchronous machine it will affect on power factor. If the synchronous motor is overexcited then it will have leading power factor and if the motor is underexcited then it will have lagging power factor.

1 answer
582 views

Description : The effect of increasing load on a synchronous motor running with normal excitation is (A) Increase both its Ia and power factor. (B) Decrease Ia, but increase power factor. (C) Increase Ia, but decrease power factor (D) Decrease both Ia and power factor.

Last Answer : The effect of increasing load on a synchronous motor running with normal excitation is Increase Ia, but decrease power factor

1 answer
79 views

Description : How can we improve power factor using synchronous motor?

0 answers
108 views

Description : If we change the excitation of synchronous machine will it affect on motor speed?

Last Answer : No, If we change the excitation of synchronous machine it will not affect on motor speed.

1 answer
203 views

Last Answer : A synchronous motor running with normal excitation adjusts to load increases essentially by increase in armature current.

1 answer
377 views

Description : what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?

Last Answer : When excitation of an unloaded salient pole synchronous motor suddenly gets disconnected the motor will stop.

1 answer
176 views

Description : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?

Last Answer : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because stator supply is not required to produce magnetic field.

1 answer
158 views

Description : If the load of the normally excited synchronous motor is increased the power factor will?

Last Answer : If the load of the normally excited synchronous motor is increased the power factor will become lagging.

1 answer
507 views

Description : If the field of synchronous motor is under excited, power factor will be?

Last Answer : If the field of synchronous motor is under excited, power factor will be lagging.

1 answer
132 views

Description : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load  (A) The armature current increases and the power factor decreases  (B) The armature ... but is lagging  (D) The armature current decreases and the power factor increases and is leading

Last Answer : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load The armature current decreases and the power factor increases and is leading

1 answer
354 views

Description : In a synchronous generator delivering lagging power factor load  (1) the excitation emf leads terminal voltage by the power angle (2) the excitation emf lags terminal voltage by the power angle (3) ... by the power factor angle (4) excitation emf lags the terminal voltage by the power factor angle

Last Answer : In a synchronous generator delivering lagging power factor load the excitation emf leads terminal voltage by the power angle

1 answer
103 views

Description : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are 0.866 pu, 0.5 pu

1 answer
100 views

Description : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu

Last Answer : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is 0.5 pu

1 answer
169 views

Last Answer : For a D.C. shunt motor if the excitation is changed torque will change but power will remain constant.

1 answer
101 views

Last Answer : The standard full-load power factor ratings for synchronous motors are unity or 0.8 leading.

1 answer
112 views

Last Answer : For power factor correction, synchronous motors operate at no-load and greatly over-excited fields.

1 answer
190 views

Last Answer : In a distribution system, in order to improve power factor, the synchronous capacitors are installed at the receiving end.

1 answer
92 views

Description : Can a synchronous condenser improve power factor?

Last Answer : Yes, synchronous condenser can improve power factor.

1 answer
153 views

Description : At which time power factor of the induction motor is low?

Last Answer : The power factor of the inducction motor is low at the time of starting as compare to while the induction motor is running.

1 answer
249 views

Description : The synchronous motor will develop maximum power when the load angle is?

Last Answer : The synchronous motor will develop maximum power when the load angle is 900.

1 answer
571 views

Description : A three-phase synchronous motor connected to ac mains is running at full load and unity power factor. lf its shaft load is reduced by half and field current is held constant then its new power factor will be

Last Answer : Leading

2 answers
121 views

Last Answer : When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.

1 answer
216 views

Last Answer : The power factor of a single-phase induction motor is usually lagging.

1 answer
94 views

Last Answer : An induction motor has relatively high power factor at near full load.

1 answer
2.8k views

Description : For a 500 Hz frequency excitation, a 50 km long power line will be modeled as

Last Answer : For a 500 Hz frequency excitation, a 50 km long power line will be modeled as long line

1 answer
92 views

Description : Damper winding in a synchronous motor

Last Answer : Damper winding in a synchronous motor Serves to start the motor.

1 answer
113 views

Last Answer : In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will run as induction motor.

1 answer
229 views

Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.

1 answer
137 views

Last Answer : If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in damage to the starting winding.

1 answer
75 views

Description : Why synchronous motor Cannot start itself?

0 answers
74 views

Description : What is the principle of synchronous motor?

0 answers
68 views

Description : What is the use of synchronous motor?

0 answers
67 views

Description : Why the speed of synchronous motor is constant?

0 answers
517 views

Description : In synchronous motor, does the winding losses vary with load?

Last Answer : No, in the synchronous motor the winding losses do not vary with load.

1 answer
261 views

Description : what is the difference between synchronous and asynchronous motor?

Last Answer : Asynchronous motors and syncrouns motor are called as dc machines.  and also syncrouns motor called as induction motor. Asynonymous motor as are rotates with constant speed we not able to operate . ... It is able to operate. These are a small difference between syncrouns and asynchronous motors. 

2 answers
207 views

Description : The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

Last Answer : Ns         equals        f/pair pole 50/4      - 12.5

2 answers
438 views

Description : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then (A) It would over-run the other alternator (B) Its rotor ... (C) Its portion of share in load will increase (D) Its power factor would be decreased.

Last Answer : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then Its portion of share in load will increase

1 answer
100 views

Description : The armature reaction in a synchronous generator supplying leading power factor load is (A) magnetizing (B) demagnetizing (C) demagnetizing and cross-magnetizing (D) magnetizing and cross-magnetizing

Last Answer : The armature reaction in a synchronous generator supplying leading power factor load is magnetizing and cross-magnetizing

1 answer
310 views

Description : How can we reverse the direction of rotation of synchronous motor?

Last Answer : By reversing supply phase sequence we can reverse the direction of rotation of synchronous motor.

1 answer
92 views

Description : Can we use the synchronous motor as the synchronous capacitor?

Last Answer : Yes, we can use the synchronous motor as the synchronous capacitor when the synchrnous motor is overexcited.

1 answer
171 views

Description : List different starting methods of three phase synchronous motor. Explain any one of them.

Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor. 

1 answer
525 views

Description : Draw and explain V and inverted V curves for synchronous motor.

Last Answer : V curves' and inverted V curves' for Synchronous Motor:  V curve:  V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted ... Vcurves of synchronous motor. The highest point on each of these curves indicates unity power factor.

1 answer
128 views

Description : List different torques in synchronous motor. 

Last Answer : Different Torques in Synchronous Motor: 1) Starting torque 2) Running torque 3) Pull-in torque 4) Pull-out torque

1 answer
664 views

Description : In a self-controlled synchronous motor fed from a variable frequency inverter  (1) the rotor poles invariably have damper windings  (2) there are stability problems  (3) the speed of the rotor decides stator frequency  (4) the frequency of the stator decides the rotor speed

Last Answer : 2

2 answers
101 views

Last Answer : Slip-rings in a synchronous motor carry direct current.

1 answer
77 views

Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.

1 answer
125 views

Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.

1 answer
118 views

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.

1 answer
260 views

Last Answer : In case one phase of a three-phase synchronous motor is short-circuited the motor will not start.

1 answer
...