Step up transformers - confusion

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SUMMARY

Step up transformers effectively reduce power loss in electrical cables by increasing voltage and consequently decreasing current. The power loss in cables is calculated using the formula Ploss = I2R, where I represents current and R is resistance. Although increasing voltage may suggest higher power loss, it is crucial to recognize that the voltage drop in cables is dependent on the current flowing through them, not the applied voltage. A numerical example can clarify this concept further.

PREREQUISITES
  • Understanding of electrical power formulas, specifically P = I2R
  • Knowledge of transformer operation principles
  • Familiarity with voltage drop concepts in electrical circuits
  • Basic grasp of series circuit configurations
NEXT STEPS
  • Study the principles of transformer operation and efficiency
  • Learn about voltage drop calculations in electrical circuits
  • Explore numerical examples of power loss in cables
  • Investigate the impact of cable resistance on power transmission
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Electrical engineers, students studying power systems, and professionals involved in electrical design and optimization will benefit from this discussion.

yllihp
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I know step up transformers decrease power loss by the electrical cables, but I'm not quite sure how this works...

From what I understand, step up transformers increase voltage, hence decrease current, which means less power is dissipated by the cables since P=(I^2)R.

But then couldn't you argue that since step up transformers increase voltage, then actually the power dissipated by the cables increases since P=(V^2)/R ??

Could someone please enlighten me??
 
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It is not like that.
Power loss in a cable is given by
Ploss =I^2 R
The voltage drop V in the cable depends on current I passing through the cable.
This V is not the applied voltage Vs. Instead
Vs= V+Vl
where Vl is the load voltage (because resistance of cable is in series with load)

So your second equation, though it is correct, has to be understood properly. A numerical example may help you to understand.
 

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