How to Solve Power Factor Problems with Mixed Loads?

[fan_103]

Hi guys I am having problems with this question,can u help me?!?thnks

3. The loads taken from an a.c. supply consist of:
(a) a heating load of 15 kW;
(b) a motor load of 40 kVA at 0.6 power factor; and
(c) a load of 20 kW at 0.8 lagging power factor.
Calculate:
(i) the total load from the supply in kW and kVA and its power factor,
(ii) the kVA rating of the capacitor to bring the power factor to unity.
Draw the power triangle and show how the capacitor would be connected to the
supply and the loads.
Power factor=Cosine angle(between supply voltage and current)
ANS:59kW, 75.4 kVA, 0.782; 47 k Ar

 

[MATLABdude]

As per the forum rules, you need to show some work. I'll help you out, however: decompose each of these loads (into real and reactive power) using the power triangle, and then find the resultant of real and reactive powers to find your total apparent power.

EDIT: Power triangle:
http://en.wikipedia.org/wiki/Electric_power#Alternating_current