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
6
0
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
5,448
784
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.

3. khairulnashrul New Member

Aug 15, 2017
1
0
Hello, can you please explain more on how you got that answer? i'm having a difficulty with a similar question too.

4. WBahn Moderator

Mar 31, 2012
20,220
5,744
I wouldn't hold my breath for a response to a thread that's been dead for over six years.

But if you show your best attempt to work either this problem (in this thread), or start a new thread with your problem and your best attempt to work it, then you will likely get a lot of guidance from the membership.