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The inductance of the transformer is much higher than the resistance of the transformer, resulting in very low real power losses (in watts), but some reactive power (vars).
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How does power factor affect your power bill?
A poor power factor causes the meter to rotate more slowly than it should, so a poor power factor would reduce your bill. Electric utilities compensate for this in commercial services by billing based on power factor, or they install a meter that actually measures power factor.AnswerEnergy meters 'read' the in-phase component of load current (therefore the load's 'true power' multiplied by time) and, so, are completely unaffected by the power factor of a load. So the power factor of a residential load will have absolutely no effect whatsoever on that residence's 'energy' (not 'power') bill.Industrial and commercial consumers are billed for 'demand' (their rate of consumption of energy -i.e. the power) as well as energy supplied'. In addition, these consumers are usually penalised if the power factor of their load falls below an agreed value. So power factor does affect the overall bill (but not the energy bill) of industrial consumers.
What is the effect of power factor on the cost of generation?
The effect of low (or 'poor') power factor is that a given load requires more load current than at high power factors. So, to accommodate these higher currents, a greater volume of copper is required in the supply cables, switchgear, transformers, etc. So much greater capital costs are required if low power loads are supplied.
Why unity power factor is not economical?
If you have a poor power factor (say .8), and your local utility requires you to have .95pf or better, or be charged extra due to the poor power factor, there is no economic reason to buy more equipment to bump your power factor up to 1.0 as opposed to .95. Once you're above .95, you're just fining yourself.
What are the causes of overheating of distribution transformer?
poor cooling mechanisms, and overloading.
Why improve power factor?
A poor power factor is usually caused by coils; by inductors within electric motors. A capacitor is the opposite of a coil, and can improve the power factor by moving the current phase angle forward, more towards the voltage. Power factor degradation from inductive loads occurs because inductors resist a change in current, by "presenting" a higher resistance to a step (or any) change in current. As a result, current lags voltage, and power factor suffers. Capacitors are opposite to inductors. They resist a change in voltage, by "presenting" a lower resistance to a change in voltage. As a result, current leads voltage. Suppose that a capacitor is placed in parallel to an inductor. If the value of capacitance is adjusted so it exactly cancels the inductance at 60Hz, then the combination as a whole behaves purely as a resistor. If capacitive loads were common, then they would cause problems similar to inductors. However, adding capacitance in a case where there is also inductance serves to raise voltage, particularly since the conductors (power lines, etc.) leading up to the load are also resistive, inductive, and partially capacitive. By raising the voltage, power factor is improved, and the inductive loads (usually motors) cause fewer losses in power lines.
Why transformer rating is called kva not kw?
Transformers are rated in KVA because that is a more accurate way to measure their capacity requirements. KWH is apparent power, while KVA is true power, and the ratio between them is power factor. The power factor is a function of the load, and not the transformer, so a poor power factor would make KWA look less to the transformer while, in fact, the true power, if not met by the transformer, could overload the transformer.
Why unity power factor is used in load test?
When power factor is at unity, the voltage and current waves are aligned or in phase with one another. Since power is the product of voltage and current, power transfer is maximized at unity power factor. When power is transmitted at a lower power factor, greater current is required to deliver the same amount of power. When current is increased, the size of the transmission, distribution and generation systems, all have to be increased accordingly, along with the price of the killowatt-hour at the meter.
Is Poor power factor causes overload on alternator transformer and distribution lines?
yes it is true gal or boy what everAnother AnswerPoor power factor doesn't necessarily cause an 'overload' (transmission/distribution systems are designed to cope), but it is certainly responsible for a load drawing more current than necessary. This is because a load with a poor (low) power factor draws more current than is necessary to supply the same amount of energy.
Why can a reactive power load drop the voltage more than the active power load in a transmission line?
A load with a poor power factor draws extra current from the power supply, meaning that there will be more of a voltage-drop in the supply. As an example, if the load is 6 kW on a 240 v supply, the current drawn is 25 amps if the load has a power factor of 1. The kVA is equal to the kW. But if the load has a power factor of 0.8 it needs to draw 7.5 kVA for a power of 6 kW, which is a current of 31.25 amps, so there is more of a demand on the power supply wiring etc. The transmission losses increase by 56% with the extra current. In both cases the customer is charged for power used, 6 kW. That is why the supply companies do not like loads with a poor power factor and sometimes charge commercial customers more for a poor power factor. That in turn makes it viable for the customers to correct the power factor of the load they place on the supply.
How does power factor affect your power bill?
A poor power factor causes the meter to rotate more slowly than it should, so a poor power factor would reduce your bill. Electric utilities compensate for this in commercial services by billing based on power factor, or they install a meter that actually measures power factor.AnswerEnergy meters 'read' the in-phase component of load current (therefore the load's 'true power' multiplied by time) and, so, are completely unaffected by the power factor of a load. So the power factor of a residential load will have absolutely no effect whatsoever on that residence's 'energy' (not 'power') bill.Industrial and commercial consumers are billed for 'demand' (their rate of consumption of energy -i.e. the power) as well as energy supplied'. In addition, these consumers are usually penalised if the power factor of their load falls below an agreed value. So power factor does affect the overall bill (but not the energy bill) of industrial consumers.
How do you reduce power factor value?
No-one ever aims to reduce the power factor, the ideal power factor is equal to 1, and that is the maximum possible value. A load with a power factor of 0.7 draws 40% more current along the supply wires compared to a equal-power load with a power factor of 1. That means that the power loss in the resistance of the supply wires is doubled in the case of the poor power factor. Since the supply company receives no extra revenue for the lost power, it does not like this situation and sometimes penalises users with poor power factors with extra tariffs. The power factor can often be improved by placing a passive reactor in parallel with the load to draw off the reactive volt-amps (VAR or kVAR) so that the supply wiring sees a load with a good power factor. Normally a bad load like a motor draws inductive VARs and in this case it can be corrected with a parallel capacitor that draws an equal number of capacitive VARs. Looked at another way, the added capacitor 'tunes' the load to resonate at the supply frequency.
What is APFC panel?
An Automatic Power Factor Correction (Controller) panel is used to Save Energy by consistently maintaining higher power factor. Low Power Factor leads to poor power efficiency, thereby increasing the apparent power drawn from the distribution network. This results in overloading of Transformer, Bus bars, Switch gears, Cables and other distribution devices within the Industry or consumer area.With an APFC the energy producer can:Avoid Penalization for lower power factor.Enjoy incentives for higher power factor operation being extended to Industries by some Electricity Boards/ Companies.Optimize the connected load for improved plant load factor.Avoid manual disruption.Avoid high current consumption losses.Improvement in voltage regulation.Decrease Maximum Demand KVA, thus avoiding penalty and Demand Charges.
How many amps does a 240 volt 12VA transformer draw?
12/240, 0.05 amps, maybe about 30% more because of the poor power factor of small transformers.
How many amps does a 240 volt 10000 watt load draw?
Minimum current would be 10000 divided by 240 but it might be up to 30% more if the load has a poor power factor.
What is the effect of power factor on the cost of generation?
The effect of low (or 'poor') power factor is that a given load requires more load current than at high power factors. So, to accommodate these higher currents, a greater volume of copper is required in the supply cables, switchgear, transformers, etc. So much greater capital costs are required if low power loads are supplied.
What are the adverse effects of poor power factor?
Low power factor means higher than necessary load currents. These require unnecessary expenditure on the amount of copper in supply equipment such as cables, transformers, and switchgear. Higher than necessary load currents also mean greater voltage drops and poorer voltage regulation.
Why power factor is used?
Power factor is the ratio of real power over apparent power. In a purely resistive load, real and apparent power are the same, so the power factor is one. In a reactive load, such as an inductive or capacitative load, however, current lags (for inductive) or leads (for capacitative) the voltage. This phase angle means that, at certain portions or phases of the line cycle, the load is feeding power back into the source. A wattmeter connected would read lower than actual, so the apparent power would be less than the real power, and the power factor would be less than one. In fact, if the load were truly reactive, such as an ideal inductor or capacitor, the current would lag or lead by 90 degrees phase angle, and the power factor would be zero. Power would still be supplied and used, but the meter would stand still. Power factor is used to compensate for the "error" in the meter, so that the user can be charged correctly for their true power usage. Power factor is also used to determine the amount of capacitative or inductive compensation to use on a circuit to correct a poor power factor.
