1. ECE 201 Circuit Theory I1 Complex Power Designate as S Magnitude of S = Apparent Power Units are Volt-Amperes The complex sum of Real Power (P) and Reactive Power (Q)

2. ECE 201 Circuit Theory I2 Graphical Interpretation of S Power Triangle

3. ECE 201 Circuit Theory I3

4. 4 Summary

5. ECE 201 Circuit Theory I5 Summary -- 2 P = Useful Output from the device being powered (Watts) Apparent Power – the volt-amp capacity required to supply P Q = Power exchanged between source and load

6. ECE 201 Circuit Theory I6 Summary -- 3 If the power factor angle is = 0, Apparent Power = Average Power (and Reactive Power = 0).

7. ECE 201 Circuit Theory I7 Example 10.4 Calculating Complex Power An electrical load operates at 240 V rms. The load absorbs an average power of 8 kW at a lagging power factor of 0.8. Calculate the complex power of the load. Calculate the impedance of the load.

8. ECE 201 Circuit Theory I8 The power factor is “Lagging”, so we have an inductive load. The Reactive Power, Q, is Positive.

9. ECE 201 Circuit Theory I9

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