What is synchronous condenser or phase advancer?

1 Answer

Answer :

An over excited synchronous motor takes leading current just like a condenser and gives leading power factor. A synchronous motor, which I used only for the purpose of improving power factor, can be called as synchronous condenser or phase advancer.

Related questions

Description : Distinguish between synchronous phase modifier and synchronous condenser

Last Answer : A synchronous motor used to change the power factor or power factor in the supply lines is called synchronous phase modifier. A synchronous motor operated at no load with over excitation condition to draw large leading reactive current and power is called a synchronous condenser.

Description : In order to improve the power factor ___ device is employed in the substation a) Synchronous condenser b) Synchronous reactor c) Series Capacitors d) None of the above

Last Answer : Ans: A

Description : What is synchronous Condenser? Where and why it is used?

Last Answer : An overexcited synchronous motor running at no- load and used for power-factor correction is called synchronous condenser. It is also called synchronous capacitor. It is used in a large system where the use of static capacitor is inefficient and expensive. It is used for power-factor correction.

Description : What is meant by synchronous condenser?

Last Answer : An over excited synchronous motor running on no load is known as synchronous condenser. It is used to improve the power factor of the system.

Description : How the synchronous motor can be used as s synchronous condenser?

Last Answer : Synchronous motor is operated on over excitation so as to draw leading reactive current and power from the supply lines. This compensates the lagging current and power requirement of the load making ... to become unity. The motor does the job of capacitors and hence called as synchronous condenser.

Description : What is synchronous condenser?

Last Answer : An over-excited synchronous motor under no load , used for the improvement of power factor is called as synchronous condenser because, like a capacitor it takes a leading current.

Description : What is Synchronous Condenser ?

Last Answer : When an over-excited synchronous motor is connected to a line to enhance the power factor without load , it is called a synchronous condenser.

Description : What is a synchronous condenser?

Last Answer : A synchronous condenser is a device identical to a synchronous motor, whose shaft is not connected to anything but spins freely. Its purpose is not to convert electric power to mechanical power or vice ... or absorb reactive power as needed to adjust the grid's voltage, or to improve power factor.

Description : Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical ? (a) Static condenser (b) Synchronous condenser (c) Tap changing transformer (d) Booster transformer

Last Answer : (d) Booster transformer

Description : Can a synchronous condenser improve power factor?

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

Description : where the synchronous condenser are generally installed ?

Last Answer : the synchronous condenser are generally installed at receiving end side of transmission line 

Description : What is Synchronous condenser?

Last Answer : Synchronous condenser Big advantage of synchronous condenser is their large temporary overload capability and good harmonics performance. Synchronous condenser is ... ;voltage levels. Synchronous condenser have slow speed of response.

Description : A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3

Last Answer : Answer: A

Description : The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Last Answer : Answer: C

Description : A shaded-pole motor is a ____________. A. synchronous motor B. three-phase induction motor C. compound-wound motor D. single-phase induction motor

Last Answer : Answer: D

Description : Why a 3-phase synchronous machine will always run at synchronous speed?

Last Answer : Because of the magnetic coupling between the stator poles and rotor poles the motor runs exactly at synchronous speed.

Description : What could be the reasons if a 3-phase synchronous motor fails to start?

Last Answer : It is usually due to the following reasons a. Voltage may be too low. b. Too much starting load. c. Open circuit in one phase or short circuit. d. Field excitation may be excessive

Description : What is the effect on speed if the load is increased on a 3 phase synchronous motor?

Last Answer : The speed of operation remains constant from no load to maximum load in the motor operating at constant frequency bus bars.

Description : A single phase Hysteresis motor (A) can run at synchronous speed only (B) can run at sub synchronous speed only (C) can run at synchronous and super synchronous speed (D) can run at synchronous and sub synchronous speed

Last Answer : Ans: A The rotor revolves synchronously because the rotor poles magnetically lock up with the revolving stator poles of opposite polarity

Description : The synchronous speed for a 3 phase 6-pole induction motor is 1200 rpm. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% will be _________. (A) 1690 rpm (B) 1750 rpm (C) 1500 rpm (D) 1710 rpm

Last Answer : (D) 1710 rpm

Description : The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase

Last Answer : Ans: A Universal motor has same characteristics as DC series motor and also known as an a.c series motor.

Description : In a 3-phase synchronous motor (A) the speed of stator MMF is always more than that of rotor MMF. (B) the speed of stator MMF is always less than that of rotor MMF. (C) the speed of ... speed while that of rotor MMF is zero. (D) rotor and stator MMF are stationary with respect to each other.

Last Answer : Ans: D Because, Motor is magnetically locked into position with stator, the rotor poles are engaged with stator poles and both run synchronously in same direction Therefore, rotor & stator mmf are stationary w.r.t each other.

Description : The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.

Last Answer : Ans: all options are correct

Description : nswer: Option B 559. Heat release during phase change is observed in case of a/an (A) Boiler (B) Condenser (C) Evaporator (D) All (A), (B) & (C)

Last Answer : (B) Condenser

Description : Which of the device is employed in substation to limit the short circuit current in the power system: a) Shunt condenser b) Reactor c) Series capacitor d) Shunt capacitor

Last Answer : Ans: B

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0042 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : A device used in an electrical circuit to change alternating current to direct current, is known as a _____________. A. current transformer B. rectifier C. condenser D. shunt

Last Answer : Answer: B

Description : In the illustration if the compressor fails to start but the condenser fan motor is running the problem is _______. EL-0043 A. no power between L1 and L2 B. the yellow wire is open at the freezer temperature control switch C. the overload is open D. the blue wire from the defrost heater is open

Last Answer : Answer: C

Description : What are the purposes of bleed condenser?

Last Answer : The purposes of bleed condenser are, a. To cool the bleed water, which goes to bleed cooler.  b. To provide cool hot water to the PHT purification system. 

Description : By which material condenser tubes are made?

Last Answer : Condenser tubes are made up of aluminium brass.  

Description : Why condenser back-pressure must be low? How it is achieved? 

Last Answer : Condenser back- pressure must be low, because steam should be dumped into the condenser so as to recycle it to boiler through the recycle process. It improves efficiency of the turbine, as the heat ... water in the condenser through the tubes of the condenser so that maximum vacuum can be obtained.

Description : Growth curve does not include following phases of bacteria – a. Decline phase b. Stationary phase c. Lag phase d. Synchronous growth

Last Answer : Ans: D

Description : A three-phase synchronous motor has a terminal voltage of 460 V and a terminal current of 120 A at a power factor of 0.95 lagging, synchronous reactance of 1.68 ohm and the field current is 47 A. The field to armature mutual ... _____________.      (a). 20mH   (b). 16mH   (c). 24mH   (d). 22mH

Last Answer : 22

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. 

Description : A 100 MVA, 11 KV, 3-phase, 50 Hz, 8—pole synchronous generator has an inertia constant H equal to 4 seconds. The stored energy in the rotor of the generator at synchronous speed will be  A) 100 MJ B) 400 MJ C) 800 MJ D) 12.5 MJ

Last Answer : 800

Description : A 500 MW, 3-phase, Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 p.f. The line current when operating at full load rated conditions will be  (A) 13.43 kA (B) 15.79 kA (C) 23.25 kA (D) 27.36 kA

Last Answer : A 500 MW, 3-phase, Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 p.f. The line current when operating at full load rated conditions will be 15.79 kA

Description : The synchronous speed for the seventh space harmonic mmf wave of a 3-phase, 8-pole, 50 Hz induction machine is  (A) 107.14 rpm in forward direction (B) 107.14 rpm in reverse direction (C) 5250 rpm in forward direction (D) 5250 rpm in reverse direction

Last Answer : The synchronous speed for the seventh space harmonic mmf wave of a 3-phase, 8-pole, 50 Hz induction machine is 107.14 rpm in forward direction 

Description : A three phase, salient pole synchronous motor is connected to an infinite bus. It is operated at no load a normal excitation. The field excitation of the motor is first reduced to zero ... First increases and then decreases steeply (C) First decreases and then increases steeply (D) Remains constant

Last Answer : B

Description : Damper winding is provided in 3 phase synchronous motors to :

Last Answer : Damper winding is provided in 3 phase synchronous motors to : provide starting torque and prevent hunting

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

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

Description : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is (A) 2/15 p.u. (B) 5/6 p.u. (C) 1.0 p.u. (D) 1.2 p.u.

Last Answer : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is 5/6 p.u.

Description : The maximum possible power of a 3-phase synchronous motor with synchronous reactance 0.8 p.u. connected to a bus-bar of 1.0 p.u. and excitation adjusted to 1.2 p.u. is (A) 0.5 p.u. (B) 0.96 p.u. (C) 1.5 p.u. (D) 1.8 p.u.

Last Answer : The maximum possible power of a 3-phase synchronous motor with synchronous reactance 0.8 p.u. connected to a bus-bar of 1.0 p.u. and excitation adjusted to 1.2 p.u. is 1.5 p.u.

Description : A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading. Neglecting losses, the torque developed will be

Last Answer : A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading. Neglecting losses, the torque developed will be 1165 Nm

Description : A 3~phase synchronous motor, connected to infinite bus, is operating at no load at normal excitation. The field excitation of the motor is first decreased to zero and then increased in the ... 2) First decrease and then increase, (3) Increases continuously (4) First increase and then decreased

Last Answer : A 3~phase synchronous motor, connected to infinite bus, is operating at no load at normal excitation. The field excitation of the motor is first decreased to zero and then increased in the reverse direction. The armature current of the synchronous motor will: Increases continuously.

Description : In a 3-phase synchronous motor;  (A) the speed of the stator MMF is always more than that of the rotor MMF (B) the speed of the stator MMF is always less than that of the rotor MMF (C) the ... that of the rotor MMF is zero (D) the rotor and the stator MMF are stationary with respect to each other

Last Answer : In a 3 -phase synchronous motor:  the rotor and the stator MMF are stationary with respect to each other

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

Description : An unexcited single phase synchronous motor is ?

Last Answer : An unexcited single-phase synchronous motor is reluctance motor.

Description : Three phase synchronous motor will have how many sliprings?

Last Answer : Three phase synchronous motor will have two sliprings.

Description : Induction generator a) can not work in isolation b) can work in isolation c) should work in parallel with synchronous generators d) any of the mentioned

Last Answer : Ans: C