Power Factor Proof: Avoid Poor PF < 0.8

In summary, the conversation discusses a homework problem regarding generalizing the circumstances required to avoid a poor power factor in a circuit. The equations for power factor, real power, and apparent power are mentioned along with the variables for resistance, inductance, and capacitance. The solution is simplified to PF = R / sqrt(R^2+(xl-xc)^2) and the value of the apparent power approaching the value of the real power is discussed. It is concluded that when Xl=Xc, the power factor is equal to 1 and as Xl-Xc approaches zero, the apparent power approaches the value of the real power. The conversation ends with the acknowledgement of a mathematical proof being sufficient to prove this concept.
  • #1
physics97
6
0

Homework Statement


Hi guys, I am having trouble with my homework, it states to generalise the circumstances required to avoid a poor power factor (assumed to be less then 0.8) of a circuit, this generalisation must then be proved. Any help would be greatly appreciated.


Homework Equations


Power Factor = Real Power / Apparent Power
Real Power = I^2*R
Apparent Power = I^2*Z
Z=sqrt(R^2+(Xl-Xc)
Where:
R is resistor
Xl is inductor
Xc is capacitor
in ohms

The Attempt at a Solution

 
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  • #2
What happens if you use your equations to express the power factor with R, Xl and Xc?
 
  • #3
mfb said:
What happens if you use your equations to express the power factor with R, Xl and Xc?
Simplifies down to:
PF = R / sqrt(R^2+(xl-xc)^2) ?
 
  • #4
Getting to the point where this is urgent, anyone able to help?
 
  • #5
How do you make the value of the apparent power approach the value of the real power?
 
  • #6
SteamKing said:
How do you make the value of the apparent power approach the value of the real power?
When Xl=Xc the power factor is equal to 1 (easily proven), so i suppose that as Xl-Xc approaches zero, the apparent power approaches the value of the real power. My problem is I am truly stumped on how i could prove it, any suggestions?
 
  • #7
physics97 said:

Homework Statement


Hi guys, I am having trouble with my homework, it states to generalise the circumstances required to avoid a poor power factor (assumed to be less then 0.8) of a circuit, this generalisation must then be proved. Any help would be greatly appreciated.


Homework Equations


Power Factor = Real Power / Apparent Power
Real Power = I^2*R
Apparent Power = I^2*Z
Z=sqrt(R^2+(Xl-Xc)
Where:
R is resistor
Xl is inductor
Xc is capacitor
in ohms

The Attempt at a Solution


Error in an equation * Z=sqrt((R^2)+((Xl-Xc)^2))
 
  • #8
physics97 said:
When Xl=Xc the power factor is equal to 1 (easily proven), so i suppose that as Xl-Xc approaches zero, the apparent power approaches the value of the real power. My problem is I am truly stumped on how i could prove it, any suggestions?

Didn't you just prove it? I think even EEs must accept a mathematical proof as sufficient.
 
  • #9
SteamKing said:
Didn't you just prove it? I think even EEs must accept a mathematical proof as sufficient.

Thanks for your help mate, greatly appreciated
 

Related to Power Factor Proof: Avoid Poor PF < 0.8

1. What is power factor proof?

Power factor proof is a measure of the efficiency of an electrical system. It represents the ratio of real power, which is the power used to perform work, to apparent power, which is the power supplied to the system. A power factor of less than 0.8 indicates that the system is not operating at optimal efficiency.

2. Why is it important to avoid a power factor of less than 0.8?

A power factor of less than 0.8 can lead to a number of issues, including increased energy consumption, higher utility bills, and decreased equipment lifespan. It can also cause voltage drops, which can affect the performance of sensitive equipment and lead to downtime and costly repairs.

3. What are the common causes of a poor power factor?

A poor power factor can be caused by a variety of factors, including inductive loads, such as electric motors, that require a large amount of reactive power. Other common causes include unbalanced loads, harmonics, and inefficient power supply systems.

4. How can I improve power factor?

There are several ways to improve power factor, including installing power factor correction equipment, such as capacitors, to reduce reactive power and improve the efficiency of the system. It is also important to regularly maintain and balance loads, as well as reduce the use of unnecessary or inefficient equipment.

5. What are the potential benefits of maintaining a good power factor?

Maintaining a good power factor can result in several benefits, including lower energy consumption, reduced utility bills, and improved equipment performance and lifespan. It can also prevent power quality issues and potential downtime, which can save businesses time and money in the long run.

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