Reactive power of a capacitor in parallel

Discussion in 'Homework Help' started by magodiafano, Feb 12, 2011.

  1. magodiafano

    Thread Starter New Member

    Feb 12, 2011
    Hi have two simple questions for you, taken from my homeworks:

    The first one is about a single phase circuit in which we have a generator of voltage (240 V) in series with an impendence (in polar form 10 amplitude, 60 phase). In the first step I have to find R,X,P, Q and power factor. This is simple.

    My problem is in the second step when a capacitor is connected in parallel to this circuit. I know that this capacitor supplies a precise quantity of VAr (1250 VAr): then I have to find P and Q supplies by the source and the new power factor.

    Is it right that I consider the Q found in the first step and then I simply add this Q with 1250? Since the real power does not change, it will be easy finding the new power factor.
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    The original load produces 4988.3 lagging VAR. The added parallel capacitance produces 1250 leading VAR. The result would then be 3738.3 lagging VAR.

    Effectively you then have the source delivering 4719 VA at power factor of 0.61 lagging.