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When you should use synchronous motor instead of capacitor for power factor correction?
Wiki User
∙ 12y ago
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.
Wiki User
∙ 13y ago
Wiki User
∙ 12y agoWe shall use Synchronous machines where inductive loads are more. Due to Inductive loads power consumption will be more due to leading power factor. To compensate this we shall use synchronous motor to improve the power factor.
Shiva Kumar.N
MBNR,AP
Wiki User
∙ 10y agoLarge electricity users like factories have to watch the power factor of the load they place on the supply. For most pieces of equipment the power factor is a lagging one and the problem therefore is to improve the power factor of the whole factory by placing a load on the supply with a leading power factor.
A synchronous motor operates at a power factor determined by the excitation current. With a low excitation the motor operates at a lagging power factor, but by increasing the excitation it can be made to operate at a unity power factor and then a leading power factor. Therefore a factory with synchronous motors has an option to improve the overall power factor by adjusting the excitation of any synchronous motors that are in use.
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How do you find whether it is inductor or capacitor if only power factor is given?
in case of inductor or capacitor power factor is always zero.as power factor is cosine of phase angle between voltage and current. in case of inductor and capacitor phase angle between voltage and current is 90 so it become zero so if given power factor is zero then it can be inductor or capacitor.
How do you differentiate a start capacitor from a run capacitor in air conditioner?
If the air conditioner has both, the run capacitor is likely the largest one. The start capacitor will only be in the circuit for a very short time, so overheating doesn't become an issue. The run capacitor must be sized for continual use.
How the capacitor valve calculate for a for a load?
I assume that you are asking how to calculate the 'value' of a capacitor? Well, it depends what it is used for. If, for example, it is used to improve the power factor of a load, then it is first necessary to determine what the load's existing reactive power is; then, you need to know what reactive power is necessary with the power factor at its desired value; finally you need to difference between the actual and the desired values of reactive power -and this will be the necessary value for the capacitor. Power factor correction capacitors are rated in reactive volt amperes, not farads.
What is the effect on the supply current if the capacitor is removed?
It depends on how the capacitor is connected and whether the supply voltage is a.c. or d.c. Assuming you are talking about a power-factor improvement capacitor (connected in parallel with an inductive load, supplied with a.c.), then the supply current will reduce.
Control diagrame of a capacitor bank and why you use capacitor banks?
---- Capacitor banks used to improve power factor(lagging) of a circuit:: This is necessary since it causes saving in power and electricity bill in following ways: 1) As p.f rises, circuit currnt decreases and hence I2R losses reduce 2) Var consumption reduces There is no tool provided here to draw the ckt diagram:: U take on PFC(power factor correction bus), then connect switch fuse, then HRC fuse, then Contactor, then overload relay and finally the capacitor bank
Purpose of capacitor bank on a sub-station electrical room?
The primary reason for a capacitor bank in an electrical substation is for power factor correction. There may also be some secondary purpose for the capacitor bank but the primary reason is power factor correction.
How to connect 3 phase power factor correction capacitor?
how to connect power capacitor with 3 phase motor
Is a power factor capacitor different from a regular capacitor?
A power factor capacitor is a power capacitor. I'm not sure what you mean by "regular". There are different types, made from different materials that have better/worse characteristics than others depending on the application. You could use any high power capacitor for power factor correction, as long as it is sized correctly for the load and voltage.
What is a correction factor capacitor?
i know that static capacitors are used to improve the power factor. power factor should be high. Static capacitor supplies lagging reactive power. That means; the current I has 2 components they are magnetising Im (watless or waste current) and useful current Iw. Iw is in phase with voltage and Im is 90 degree away. Phase angle between them is phi 1. power factor is given by cosine of phi 1. phi angle should be less so that cosine of phi is high. To make phi angle less we use capacitor; this is nothing but power factor correction and capacitor used for this is called power factor correction capacitor. now when a capacitor is connected, it induces a current Ic 180 out of phase from Im and less in magnitude from Im. therefore, now the magnetising current is Im1=Im-Ic. due to this the phase angle reduces to phi 2. now the new power factor is cosine of phi 2. it is improved power factor.
How does a capacitor work in various industrial and domestic appliances and examples of capacitor in use?
Capacitor is connected parallel to the line which serves as power factor correction, increase line efficiency, voltage stability and reduced line losses and voltage drop.
Why capacitor can be defined in kvar?
Capacitors designed to be used for power-factor correction are rated in reactive volt amperes, rather than in farads.The reason for this is that in order to determine the necessary correction, a load's existing reactive volt amperes is first calculated, then the reactive volt amperes of the capacitor must be determined in order to achieve the required value of power factor. In other words, the capacitance (in farads) of the capacitor is irrelevant to the calculation.
What is synchronus capacitor?
A synchronous condenser (also known as a synchronous capacitor or synchronous compensator) is a DC-excited synchronous computer (large rotating generators) whose shaft is now not connected to any using equipment.
How can fluctuation in power factor be improved in single operating generator due to change in loads?
Power factor correction is normally done with a single capacitor bank. If the PF fluctuates due to a change in load, the best solution is to design and fit power factor correction capacitors at each individual reactive load that may start or stop during normal operation. Connect the PF correction directly accross the load, such that when the starter or disconnect is open, the load AND the capacitor is removed from the line, and when the disconnect is closed, both the load AND the PF capacitor is energized. Continuous loads can still be bulk-corrected with a capacitor bank, this will minimize the number of individual correction capacitors you will have to design. If properly done, your PF can be made to be very stable, with little change as the load varies.
Which type of a capacitor is used for power factor correction?
A.C capacitorAnswerGenerally speaking power-factor capacitors are oil-impregnated paper capacitors -i.e. capacitors whose dielectric is manufactured from oil-impregnated paper. Power-factor capacitors are rated in reactive volt amperes, rather than in farads.There is no such thing as an 'AC capacitor', as all capacitors (other than polarised capacitor) can operate on either AC or DC.
What is characteristic of power factor in capacitor?
Power factor characteristic in a capacitor is a measurement of how efficiently a capacitor uses electrical energy.
How do you find whether it is inductor or capacitor if only power factor is given?
in case of inductor or capacitor power factor is always zero.as power factor is cosine of phase angle between voltage and current. in case of inductor and capacitor phase angle between voltage and current is 90 so it become zero so if given power factor is zero then it can be inductor or capacitor.
What is the correction factor in gear?
Co efficient increasing/degreasing the contact circle is the correction factor in gear.
