S YNCHRONO US GENERA TORS 



35 



resistance. In calculating the leakage reactance assume 8 

 leakage lines per ampere per inch of inductor. The open- and 

 short-circuit characteristics are given by the following data: 



(a) Calculate the regulation of this generator by the general 

 met hod for an inductive load of 15 kw. at 0.8 power factor. 

 What is the field current calculated by this method? 



(b) Calculate the regulation of this generator for the specified 

 load by the synchronous impedance method. What is the field 

 current calculated by this method? 



(c) Calculate the regulation of this generator for the specified 

 load by the magnetomotive force method. What is the field 

 current calculated by this method? 



52. A 760-kv.-a, 2200-volt alternating-current generator 

 delivers energy directly to a 3-phase, 50-cycle system. The 

 neutral of the generator is grounded. The field structure 

 consists of 64 poles each of which is wound with 50 turns. The 

 armature core has 384 slots with 3 inductors in series per slot. 

 The length of the armature core parallel to the shaft is 10 in. 

 The effective resistance of the armature winding is 0.172 ohm per 

 phase. In calculating the leakage reactance assume 6.5 leakage 

 lines per ampere per inch of slot per inductor. The open- and 

 short-circuit characteristics are given by the following data: 



(a) Calculate the regulation of thU generator t, 

 overload current at unit power factor by the general method. 

 What is the field current calculated by this method? 



