8.10 COMPLEX POWER UNDER SINUSOIDAL STEADY-STATE CONDITION

Can we get the P and Q values from the voltage phasor and the current phasor straightaway by multiplying them together? We will try. Let V = Vrmsφv V rms be the voltage phasor and I = Irmsφi A rms be the current phasor; both specified as rms quantities. Then,

 

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We are not able to identify P or Q in the real and imaginary parts of this quantity since we know that P = VrmsIrms cos(φvφi) and Q = VrmsIrms sin(φvφi), but this observation prompts us to try VI* instead of VI

 

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