What are the disadvantages of having low power factor?

In summary, different voltage levels are used from generation to consumer in order to efficiently transmit and distribute electricity. The optimum generation voltage may vary depending on the specific power system, but it is typically chosen based on factors such as cost, efficiency, and safety. The standard voltage levels used in the United States are 480V for industrial and commercial use, 240V for residential use, and 120V for smaller devices. However, voltage levels can range from 11kV to 765kV in the transmission and sub-transmission stages, and from 0.4kV to 33kV in the distribution stage. These levels are carefully chosen to balance the amount of power being transmitted and the cost of the infrastructure needed to
  • #1
sirsajid
13
0
What are the disadvantages of having low power factor?
 
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  • #2
This is from the excellent article in Wikipedia about Power Factor:

The significance of power factor lies in the fact that utility companies supply customers with volt-amperes, but bill them for watts.
Power factors below 1.0 require a utility to generate more than the minimum volt-amperes necessary to supply the real power (watts).

This increases generation and transmission costs. For example, if the load power factor were as low as 0.7, the apparent power would be 1.4 times the real power used by the load.

Line current in the circuit would also be 1.4 times the current required at 1.0 power factor, so the losses in the circuit would be doubled (since they are proportional to the square of the current).

Alternatively all components of the system such as generators, conductors, transformers, and switchgear would be increased in size (and cost) to carry the extra current.

You can read the rest of it here:
http://en.wikipedia.org/wiki/Power_factor
 
  • #3
vk6kro said:
This is from the excellent article in Wikipedia about Power Factor:

The significance of power factor lies in the fact that utility companies supply customers with volt-amperes, but bill them for watts.
Power factors below 1.0 require a utility to generate more than the minimum volt-amperes necessary to supply the real power (watts).

This increases generation and transmission costs. For example, if the load power factor were as low as 0.7, the apparent power would be 1.4 times the real power used by the load.

Line current in the circuit would also be 1.4 times the current required at 1.0 power factor, so the losses in the circuit would be doubled (since they are proportional to the square of the current).

Alternatively all components of the system such as generators, conductors, transformers, and switchgear would be increased in size (and cost) to carry the extra current.

You can read the rest of it here:
http://en.wikipedia.org/wiki/Power_factor
Thank you very much for your answer. I have got it know.
Could you tell me the difference between switchgear and circuit breaker?
 
  • #4
Switchgear is the equipment that is used for normal operation of equipment. You turn it on. You turn it off.

Circuit breakers are for overload conditions where too much current is being drawn by a circuit and the power is removed to avoid further damage or fires.

There is some overlap in these. A circuit breaker is commonly incorporated into each power switch so that the power switch is turned off by the circuit breaker.
 
  • #5
Next homework question please!
 
  • #6
Couldn't be homework, because that isn't allowed here. :smile:

I'd rather see someone learn something than be too dogmatic about it. This one just learned about Wikipedia.
 
  • #7
Averagesupernova said:
Next homework question please!
What is the optimum generation voltage?what are the different voltage levels from the generation to the consumer, I mean generation...transmission ...sub transmission...distribution..what are voltage levels in each stage...
 

1. What is power factor and how does it impact electrical systems?

Power factor is a measure of the efficiency of an electrical system. It is the ratio of the real power (which does useful work) to the apparent power (which includes both real and reactive power). Low power factor means that a large portion of the apparent power is not being used effectively, leading to inefficiency and potential issues with the electrical system.

2. What are the main disadvantages of having a low power factor?

The main disadvantages of low power factor include increased energy costs, reduced capacity of electrical systems, and potential damage to equipment. Low power factor can also cause voltage fluctuations and decrease the overall reliability and stability of the electrical system.

3. What factors contribute to a low power factor?

A low power factor can be caused by a variety of factors, including inductive loads (such as motors and transformers), long transmission lines, and non-linear loads (such as computers and other electronic devices). These factors cause reactive power to be drawn from the grid, reducing the overall power factor.

4. How can a low power factor be improved?

Improving power factor can be achieved through a variety of methods, such as installing power factor correction devices, using energy-efficient equipment, and implementing power factor correction strategies. Additionally, reducing the use of inductive and non-linear loads can also help improve power factor.

5. What are the potential consequences of not addressing a low power factor?

If a low power factor is not addressed, it can lead to higher energy bills, reduced system capacity, and potential damage to equipment. It can also cause power outages and instability in the electrical grid, which can have significant economic and safety implications. Therefore, it is important to identify and address low power factor to ensure the efficient and reliable operation of electrical systems.

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