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How can a tuned RC circuit improve the power factor of an inductive motor circuit?
Wiki User
∙ 16y ago
The RC circuit can reduce the phase shift between the voltage and current in the power line. The phase shift is caused by the inductance of the motor. The phase shift between the voltage and current in the power line causes problems due to the presence of so called imaginary current or power that does no work but must be supplied by the power source.
Wiki User
∙ 16y ago
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Fan is inductive load or resistive load?
Inductive since it has a motor with windings.
Why external resistances are added to armature circuit in a dc motor?
extra resistance is added in order to decrease starting current and improve starting torque
What is the circuit for reversing an electric motor?
I HAVE A SMALL ELECTRIC CLOCK MOTOR THAT I NEED TO REVERSE. WHAT IS THE CIRCUIT I NEED TO REVERSE IT?
Is the active power supplied to a motor affected by placing of capacitor in parallel with the motor?
No. The capacitor may improve its power factor by altering the effective reactive power of the machine, thus reducing the current drawn from the supply.
How do you assumed power factor?
Power Factor is a maximum of one when the voltage and current in an AC waveform are in phase. Since power in watts is equal to voltage x current x power factor, you get maximum wattage with power factor = 1. This occurs with a pure resistive load. When you power an inductive load like a motor the power factor decreases and so does the delivered power. That is why motors are typically rated in VA, or volt-amperes rather than watts. So y Ou can assume power factor = 1 when you have a load measured in watts like a light bulb or space heater and perhaps in the .75 range for an inefficient motor.
Describe in brief the type of power factor improvement system?
You want a power factor of 1 or 100%, which is a purely resistive circuit. If you have a motor or some other inductive load in a circuit the total voltage and total current in the circuit will not be in phase (phase shift), your power factor will be less than 1. By adding a capacitor (180 degrees out of phase with inductive load) to the circuit that has a capacitive reactance equal to the inductive reactance of the motor, you can cancel the phase shift and have an ideal power factor (no wasted power). Anything above .9 would be good.
When is the power factor of a motor 1?
When the circuit is purely resistive or in resonance, i.e. capacitive and inductive reactance cancels out.Power factor is the ratio of apparent power over true power, and is the cosine of the phase angle between voltage and current.
Which power factor is advantage lagging or leading and why?
A lagging power factor is caused by inductive reactance, which is composed of resistance and inductance -- and the resistance component lowers the supply volts. A leading power factor provides capacitive reactance that actually helps improve source voltage -- this helps motor loads run cooler.
What is the function of a capacitor in motor circuit?
Mostly capacitor is used in the induction motors to improve the power factor , and make them to work as a self starting machine. In the small size , capacity dc motor has capacitor across it to smooth running without spark
Fan is inductive load or resistive load?
Inductive since it has a motor with windings.
How can phase advancers improve the power factor?
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.
Is a motor an inductive load?
Yes.
What is a motor in a circuit?
A motor in a circuit is classed as the circuit's load.
Why natural trend to lagging power factor?
Power factor is the cosine of an AC circuit's phase angle, where the expression phase angle is the angle by which a load current lags or leads the supply voltage.Lagging phase angles and power factors occur in resistive-inductive circuits. Leading phase angles and power factors occur in resistive-capacitive circuits.Most industrial and commercial loads are combinations of heating (resistive) loads and motor (inductive) loads -in other words, resistive-inductive loads. Accordingly, lagging power factors tend to be more common than leading power factors.
When you should use synchronous motor instead of capacitor for power factor correction?
Synchronous motors show some interesting properties, which finds applications in power factor correction. The synchronous motor can be run at lagging, unity or leading power factor. The control is with the field excitation, as described below:When the field excitation voltage is decreased, the motor runs in lagging power factor. The power factor by which the motor lags varies directly with the drop in excitation voltage. This condition is called under-excitation.When the field excitation voltage is made equal to the rated voltage, the motor runs at unity power factor.When the field excitation voltage is increased above the rated voltage, the motor runs at leading power factor. And the power factor by which the motor leads varies directly with the increase in field excitation voltage. This condition is called over-excitation.The most basic property of sycho motor is that it can be use as a CAPACITOR OR INDUCTOR both. Hence in turn it improves the power factor of system.The leading power factor operation of synchronous motor finds application in power factor correction. Normally, all the loads connected to the power supply grid run in lagging power factor, which increases reactive power consumption in the grid, thus contributing to additional losses. In such cases, a synchronous motor with no load is connected to the grid and is run over-excited, so that the leading power factor created by synchronous motor compensates the existing lagging power factor in the grid and the overall power factor is brought close to 1 (unity power factor). If unity power factor is maintained in a grid, reactive power losses diminish to zero, increasing the efficiency of the grid. This operation of synchronous motor in over-excited mode to correct the power factor is sometimes called as Synchronous_condenser.
Do air conditioners use resistive load or inductive load?
resistive loadAnswerIf the current is driving a motor, then the load is resistive-inductive.
What is meant by leading and lagging pf?
Power Factor is the ratio of true vs apparent power, and comes into play with a reactive (inductive or capacitive) load. A purely resistive load, such as a light bulb or toaster, will have a power factor of 1 because the current is in phase with the voltage. An inductive load, however, such as a motor, will have a power factor less than 1 because the current lags the voltage. You could also have a capacitive load, with a power factor less than 1, but in this case the current leads the voltage.AnswerThe terms, 'leading' and 'lagging' refer to whether a circuit's load current is leading or lagging the supply voltage. Current will 'lead' in resistive-capacitive (R-C) circuits, and 'lag' in resistive-inductive (R-L) circuits. So, a 'leading power factor' indicates a leading current, and applies to R-C circuits, while a 'lagging power factor' indicates a lagging current, and applies to R-L circuits.
