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In a balanced three phase circuit, power is measured by two wattmeters, the ratio of two wattmeter readings is 2:1. Determine the power factor of the system.
1 Answer
written 2.9 years ago by |
Given:
$\dfrac{W_1}{W_2} =\dfrac{2}1 \ \ \ i.e W_1=2W_2$
To find: Power factor
$\phi{}= tan^{-1} \Big[ \dfrac{\sqrt{3}\left(W_1-W_2\right)}{W_1+W_2} \Big] = {tan}^{-1}\Big[ \dfrac{\sqrt{3}\left(W_1-W_2\right)}{W_1+W_2}\Big] = tan^{-1} \dfrac{\sqrt{3}W_2 }{3W_2} \\[2ex] ϕ=tan^{-1}(0.557)=30^{\circ} \\[2ex] Power \ factor=cosϕ=cos30^{\circ}=0.8661$