Confusion with regards to power lines and the power lost

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SUMMARY

The discussion centers on the confusion surrounding power loss in electrical transmission lines, specifically the relationship between power loss, current, and voltage. The formula for power loss, P=I²R, indicates that increasing voltage reduces current, thereby decreasing power loss. However, the user questions the validity of using P=V²/R, suggesting a potential contradiction. Clarification is provided that the relevant voltage for calculating power loss is across the transmission cables, not the load at the end of the cables.

PREREQUISITES
  • Understanding of electrical power formulas, specifically P=I²R and P=V²/R.
  • Knowledge of ohmic vs. non-ohmic conductors.
  • Familiarity with electrical transmission systems and load characteristics.
  • Basic principles of voltage, current, and resistance in circuits.
NEXT STEPS
  • Study the differences between ohmic and non-ohmic conductors.
  • Learn about electrical transmission line theory and its implications on power loss.
  • Research the impact of load characteristics on voltage and current in transmission systems.
  • Explore advanced power loss calculations in electrical engineering contexts.
USEFUL FOR

Electrical engineers, physics students, and professionals involved in power transmission and energy efficiency optimization will benefit from this discussion.

Coolamebe
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Ok, so the title was pretty vague, I'm not sure how to succinctly describe the confusion. Anyway, so I've learned that the power lost is P=I2R, and so by increasing the voltage, as P=VI and is constant, the current will be lowered, and thus the power lost will decrease.
I'm confused about a couple things. While my physics teacher was specifically talking about P=I2R, should not P=V2/R also give the value, and so by increasing the voltage we increase the power lost? Is this not a contradiction?
I feel like it could be remedied if the wires in power lines are not ohmic conductors and so half the math I did above is invalid.
Anyway, any help would be greatly appreciated, thank you!
 
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The calculation relates to the power dissipated (lost) in the transmission cables so the voltage you need is the voltage across the cables. I think you are confusing this with the voltage across the load (at the end of the cables)
 
lychette said:
The calculation relates to the power dissipated (lost) in the transmission cables so the voltage you need is the voltage across the cables. I think you are confusing this with the voltage across the load (at the end of the cables)
Can you explain this a little more in depth? My teacher explained this very superficially so I'm not too sure on this.
 

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