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Power Triangle. Learning Objectives. Define apparent power. Calculate apparent power in AC series parallel networks. Define the power triangle. Using the power triangle determine relationships between real, reactive and apparent power.
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Learning Objectives • Define apparent power. • Calculate apparent power in AC series parallel networks. • Define the power triangle. • Using the power triangle determine relationships between real, reactive and apparent power. • Determine if AC series parallel networks are inductive, capacitive, or purely resistive.
Review AC Power to a Resistive LoadAC Power to a Inductive LoadAC Power to a Capacitive Load
Review AC Power Summary
Apparent Power • For a load with voltage V and current I, the power that “appears to flow” to the load is VI where V and I are rms values. S = VI (VA) • S is called the apparent power and has units of volt-amperes (VA).
Apparent Power • In terms of load impedance Z, apparent power can be expressed S = I2Z = V2/Z (VA) • It is common to see apparent power give in kVA.
Example Problem 1 Determine the real, reactive, and apparent power.
Power Triangle • The power triangle graphically shows the relationship between real (P), reactive (Q) and apparent power (S).
Power Triangle • From the power triangle we can see that
Power Triangle • We can generalize the equations:
Real and Reactive Power • The power triangle also shows that we can find real (P) and reactive (Q) power.
Example Problem 2 Draw the power triangle for this circuit. Determine if this is an inductive, capacitive, or resistive circuit.
Example Problem 3 Determine the value of R and PT & QT. Draw the power triangle and determine S.