Topic 11: Thvenin and Norton theorems applied to A.C. linear circuits 1 [5] A 10kVA, 250V 50Hz alternator supplies a load of (7.5+j2.8) 2. (a) [3] Assume the alternator is 'ideal' so ignore winding impedance, calculate the voltage across the load (V) and the load current (IL). Use the generated voltage as reference i.e. 25040 (b) [2] Repeat the above calculation but this time modelling a "real" alternator to include the internal impedance, as shown on the equivalent circuit below. Es 250 V 50 Hz ~ j0.25 0.1 VL Fig. 1 Answers (a) Iideal = 31.252(-20.47) A, (b) V = 244.22(-1.4) A