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Explain two wattmeter method for measurement of 3 - phase power.
1 Answer
written 3.4 years ago by |
Let's consider, 2-wattmeter method to measure the power in a star connected balanced 3-phase load as shown in figure below-
From above connection diagram,
(a) Current through wattmeter W1, $I_1 =I_R$
(b) Voltage across wattmeter W1, $V_1 = V_{RB} $
(c) Current through wattmeter W2, $I_2 =I_Y$
(d) Voltage across wattmeter W2, $V_2 = V_{YB} $
$P= VI\cos\phi .....(3)$
Where, V is the voltage across the wattmeter
I is the current through wattmeter
$\phi$is the angle between V & I
$W_1= |V_1||I_1|\cos (angle\ between \ V_{1}\ and\ I_1) =| V_{RB}||I_R|\cos(angle\ between \ V_{RB}\ and\ I_R)....(4)$