Power Triangle
Input A
Input B
Results
A power triangle covers one load. Reactive power flow and voltage across a whole network are load flow studies. Load flow and power system studies →
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Power Triangle Relationships
S² = P² + Q² (Pythagorean relationship)
P = S × cos(φ) (Active power)
Q = S × sin(φ) (Reactive power)
pf = cos(φ) = P/S (Power factor)
φ = arccos(pf) (Phase angle)
Where φ is the angle between voltage and current
Frequently Asked Questions
How do you calculate kVA from kW and power factor?
Divide the active power by the power factor: S = P / pf. 9.5 kW at a power factor of 0.95 is 10 kVA.
How is reactive power calculated?
From the power triangle, Q = root(S^2 - P^2), or Q = S x sin(phi). 10 kVA at 9.5 kW gives 3.12 kVAr.
What is power factor?
The ratio of active to apparent power, pf = P / S, which is also the cosine of the angle phi between voltage and current.
Which values do I need to enter?
Any two different quantities out of apparent power, active power, reactive power, power factor and phase angle. The tool works out the other three.