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Reactive Power Question

  1. Oct 29, 2008 #1
    Assume a single-phase AC voltage applied to a series circuit with a certain impedance. Because of the real and imaginary part of the impedance, we get both real and reactive power. Now, if we were to connect a capacitor in parallel with the circuit, and if this capacitor supplies a certain amount of vars, what happens to the total reactive power of the circuit? My intuition tells me that:

    P(total) is unchanged because the capacitor is purely reactive.
    Q(total) = Q(source_before) = Q(source) + Q(cap)

    So basically by adding that capacitor, you're reducing the the reactive power supplied by the voltage source, and thus increasing the power factor. Am I right?
  2. jcsd
  3. Oct 30, 2008 #2
    Yes, indeed capacitor is a static reactive power generator.:smile:

    Creative thinking is enjoyable, Then think about your surrounding things and other thought products. http://electrical-riddles.com
  4. Oct 30, 2008 #3
    Thanks! =]
  5. Oct 30, 2008 #4
    You need to look up 'Power Factor Correction".

    Poor power factor will increase real power loss because a higher current will flow in the wiring and the generator has to be capable of supplying the higher current.
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