Determine the load - Thevenins Equivalent Circuit:

Determine the load for which the source shall transfer the maximum power if load is connected across the terminal A and B, under the following conditions :

1.      load is resistive, and

2.      load is complex

Solution

Calculation for V_TH

i =20 ∠ 0^o/11 - 3j

            = 1.692 + 0.461 j Amp

V_TH = V_AB = i (6 - 3 j) = 11.53 - 2.3 j Volt

Figure 4.66

Calculation for Z_TH

Z_TH = 5 (6 - 3 j) /11 - 3 j = 2.88 - 0.576 j Ω

Thevenin's Equivalent Circuit

Case I

Load is resistive, then value of load resistance shall be equal to magnitude of ZTH.

R_L = | Z_TH |

Case II

Load is complex :

Z L = Z ^* _TH (Complex conjugate of ZTH)

= 2.88 + 0.576 j Ω