1. 1 ELECTRICAL TECHNOLOGY EET 103/4  Define and explain sine wave, frequency, amplitude, phase angle, complex number  Define, analyze and calculate impedance, inductance, phase shifting  Explain and calculate active power, reactive power, power factor  Define, explain, and analyze Ohm’s law, KCL, KVL, Source Transformation, Thevenin theorem.

2. 2 (CHAPTER 15) SERIES AND PARALLEL AC CIRCUITS

3. 3 15.8 Parallel ac Networks  In a parallel ac network the total impedance or admittance is determined, then the source current is determined by Ohm’s law: where;

4. 4 15.8 Parallel ac Networks where; and; By Ohm’s law;

5. 5 15.8 Parallel ac Networks Power to the network; where  T is the phase difference between E and I. By Kircchoff’s current law;

6. 6 15.8 Parallel ac Networks R-LR-L Time domain: Phasor (frequency) domain:

7. 7 15.8 Parallel ac Networks R-LR-L

8. 8 R-LR-L

9. 9 R-LR-L

10. 10 15.8 Parallel ac Networks R-LR-L Admittance diagram;

11. 11 15.8 Parallel ac Networks R-LR-L

12. 12 15.8 Parallel ac Networks R-LR-L (KCL)

13. 13 15.8 Parallel ac Networks R-LR-L Phasor diagram; Power;

14. 14 15.8 Parallel ac Networks R-LR-L Power factor;

15. 15 15.8 Parallel ac Networks R-CR-C Time domain: Phasor (frequency) domain:

16. 16 15.8 Parallel ac Networks R-CR-C

17. 17 15.8 Parallel ac Networks R-CR-C Admittance diagram;

18. 18 15.8 Parallel ac Networks R-CR-C

19. 19 15.8 Parallel ac Networks R-CR-C

20. 20 15.8 Parallel ac Networks R-CR-C

21. 21 15.8 Parallel ac Networks R-CR-C (KCL)

22. 22 15.8 Parallel ac Networks R-CR-C Phasor diagram;

23. 23 15.8 Parallel ac Networks R-CR-C Waveform;

24. 24 15.8 Parallel ac Networks R-CR-C Power factor; Power;

25. 25 15.9 Current Divider Rule The basic format for the current divider rule in ac circuits is exactly the same as that for dc circuits; that is, for two parallel branches with impedances Z 1 and Z 2 :

26. 26 15.9 Current Divider Rule Example 15.17 Using current divider rule, find the current through each branch:

27. 27 15.9 Current Divider Rule Example 15.17 – solution

28. 28 15.9 Current Divider Rule Example 15.17 – solution (cont’d) By current divider rule;

29. 29 15.9 Current Divider Rule Example 15.17 – solution (cont’d) By current divider rule;