SYNCHRONOUS GENERATORS 37 



calculating the leakage reactance assume that the leakage flux 

 is 6.5 lines per ampere per inch of inductor. The data for the 

 open- and short-circuit characteristics are: 



(a) Calculate the regulation of this generator for a condensive 

 load of 3500 kw. at 0.92 power factor by the general method. 

 What is the field current calculated by this method? Assume 

 that the temperature of the armature windings is 70 C. 



(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 magneto-motive force method. What is the field 

 current calculated by this method? 



65. A 3-phase water-wheel generator whose armature winding 

 is Y-connected is rated to deliver 5000 kv.-a. at 6600 volts. 

 Normal speed is 240 rev. per min. The field structure has 30 

 poles with 67.5 turns per pole. The armature core has 360 

 slots with 2 inductors in series per slot. The length of the 

 armature core is 21.5 in. The measured resistance of the arma- 

 ture between any two terminals is 0.0836 ohm at 25 C. The 

 ratio <>t effective resistance to ohmic resistance is 1.65 at 25 C. 

 In calculating the leakage reactance assume that the leakage flux 

 is 6.") lin mpere per inch of slot per inductor. 



The open- and short-circuit characteristics are given by the 

 following data: 



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

 method for full-load kilovolt-amperes at 0.8 power factor (indue- 



