Electromagnetica Aplicada

1
AC Power Chapter 11 INEL 4075 Dr. Sandra
Cruz-Pol Professor Electrical Engineering UPRM
2
AC steady-state Power

• Electric complex power
• Effective values
• Power factor
• Coupled inductors
• Ideal Transformer

3
Coupled inductors
The sign of the M is positive if both currents
enter or both leave the coil through the dot.
4
The ideal Transformer

• N2/N1n, ratio of turns in primary and secondary
  coils
• Voltage at primary is partly induced by secondary
  current, and vice versa.

5
Ideal transformer

• If both currents enter the dots then use sign
  below
• If same polarities of the voltages are in both
  dots, then use sign below

6
Transformer for down-converting

• Converts from high voltage to low voltage to
  provide power to houses and business.
• Up-converter is used at the generator source to
  step-up voltage for more efficient transmission
  (smaller current)