0
PHASE ADVANCER:phase advancers are used to improve the power factor of induction motors.The low power factor of an induction motor is due to the fact that its stator winding draws exciting current which lags behind the supply voltage by 90 degree.If the exciting ampere turns can be provided from some other A.C. source,then the stator winding will be relieved of exciting current and the power factor of the motor can be improved.This job is accomplished by the phase advancer which is simply an A.C exciter.The phase advancer is mounted on the shaft as the main motor and is connected in the rotor circuit of the motor. It provides exciting ampere turns to the rotor circuit at slip frequency.By providing more ampere turns than required,the induction motor can be made to operate on leading power factor like an over-excited synchronous motor.
You can use power factor correction capacitors, or synchronous condensor ( which is a synchronour motor run at no load and over excited). You can also use active or passive filters if harmonics are the cause of the poor power factor.
Add your answer:
Earn +20 pts
How you improve power factor in synchronous motor?
Power Factor measures the difference in phase between the current and voltage. When they are in phase the Power Factor is defined as 1. When out of phase the value is less than 1. If they are 180 degrees out of phase the Power Factor will be zero.
Is it advisable to correct the power factor to unity?
power factor depends on the load being fed if the load is entirely resistive power factor will be unity ..if the load includes an inductor or capacitpr due to phase displacement between v and i the pf will be lag or lead respectievly
How do you calculate 3 phase power factor?
The power factor for a three phase generator is 80 percent. The generator consumes 36 kilowatts and a line to line voltage of 400 volts.
What significance has a power factor in an unbalanced system?
A three-phase 'unbalanced' system refers to the load, as the supply voltages are unaffected by load. So the phase-angle and, therefore, the power factor of each phase will be different -i.e. there will be three different power factors.
What is the phase angle at unity power factor?
Zero degrees.
How you improve power factor in synchronous motor?
Power Factor measures the difference in phase between the current and voltage. When they are in phase the Power Factor is defined as 1. When out of phase the value is less than 1. If they are 180 degrees out of phase the Power Factor will be zero.
Why do you use a phase advancer to improve the power factor?
Power Factor measures how much the current and voltage waveforms are out of phase. You get most efficient power transfer when the sine waves for voltage and current exactly match. When you multiply peak voltage and current you get the largest power. Depending on the phase relationships, you can bring the voltage and current waveforms into phase when you retard one or advance one against the other. Power Factor ranges from zero when the waveforms are 180 degrees out of phase to one when they are exactly in phase.
Is it advisable to correct the power factor to unity?
power factor depends on the load being fed if the load is entirely resistive power factor will be unity ..if the load includes an inductor or capacitpr due to phase displacement between v and i the pf will be lag or lead respectievly
What is the power factor when the current and voltage are in phase?
The power factor of a load is the cosine of the angle by which the load current lags or leads the supply voltage. So if they are in phase (phase angle is zero), then the power factor must be unity (1).
How power is flowing when voltage and phase angle is maintained same?
Assume you are saying that the current and voltage are in phase and you want to know how power is affected. When Voltage and Current are in phase the Power Factor is 1 and you have maximum power being applied. When Voltage and Current are not in phase, Power Factor decreases from 1 toward zero.
How to connect 3 phase power factor correction capacitor?
how to connect power capacitor with 3 phase motor
Power factor for pure resistive circuit?
ratio between true power and apparent power is called the power factor for a circuit Power factor =true power/apparent power also we conclude PF=power dissipated / actual power in pure resistive circuit if total resistance is made zero power factor will be zero
How power factor helps to improve circuit?
Improving power factor does nothing to improve a circuit. It merely affects the amount of current drawn by the load.
How do you calculate 3 phase power factor?
The power factor for a three phase generator is 80 percent. The generator consumes 36 kilowatts and a line to line voltage of 400 volts.
Why inductor have low power factor?
An inductor has a low power factor because it is a reactive device, and the phase angle of the current with respect to voltage is not zero. In fact, power factor is the cosine of that phase angle, which means that a power factor of 1 means no phase angle, which means a resistive load. Anything else represents a reactive load and a power factor less than 1.In an ideal case, with perfect inductors and perfect conductors, the power factor would be zero, i.e. the phase angle would be 90 degrees lagging.
Why power factor can not be unity?
Power factor can be unity. If the load is purely resistive, then the load current and supply voltage are in phase, and the load will have unity power factor.
Why the power factor improves with the load?
Power factor doesn't necessarily 'improve with the load', but it is determined by the load.
