Understanding Power Factor and Load Impedance

Click For Summary

Discussion Overview

The discussion centers around the concept of power factor in electrical systems, specifically its definitions and relationships to load impedance. Participants explore theoretical aspects and seek clarification on how different definitions of power factor relate to each other.

Discussion Character

  • Homework-related
  • Conceptual clarification

Main Points Raised

  • One participant states that power factor is defined as the ratio of average power to apparent power or as cos(theta v - theta i), where theta v and theta i are the angles of load voltage and current, respectively.
  • Another participant clarifies that the power factor is the cosine of the angle between the supply voltage and current vectors, noting that it does not equal impedance but that the angle between impedance and resistance vectors is related.
  • A later post indicates that the clarification provided was helpful to the original poster.

Areas of Agreement / Disagreement

The discussion does not reach a consensus on the relationship between power factor and load impedance, as participants express differing views on the definitions and their implications.

Contextual Notes

There are unresolved aspects regarding the definitions of power factor and load impedance, as well as the assumptions underlying the relationships discussed.

p75213
Messages
93
Reaction score
0

Homework Statement



I understand power factor is defined as (average power)/(apparent power) or cos(theta v - theta i) where theta v = load voltage and theta i = load current. Also the power factor angle is equal to the load impedance.

I don't understand how the 2 definitions of power factor equal each other or why the power factor angle equals the load impedance.

I know it's a tall order but I would appreciate it if somebody could answer these questions. Alternatively a good website or book that explains this fully.
 
Physics news on Phys.org
Your first statement means PF = Cos of the angle between V (the supply voltage) and the current vectors.
It does not equal the impedance but the angle between the impedance and the resistance vectors is the same as in my first sentence.
Hope this helps you to picture the vectors and the angle
 
See if this helps
FIG+5.jpe
 
This is what I was after.
 

Attachments

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 20 ·
Replies
20
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
6K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K