CHAPTER XIV 

 ALTERNATING CURRENT GENERATORS 



Complete tests consist of special tests and temper- 

 ature tests. 



Special tests include saturation and synchronous 

 impedance, and from these the regulation of the machine 

 is calculated as follows: 



Let V = normal voltage line, C = amperes line, R = hot 

 resistance between lines. 



Kw 

 For three-phase machines C = 



Voltage v 3 



For two-phase machines C = 



2 Voltage 



For three-phase machines, voltage drop in armature, 



For two-phase machines, C\R\ = CR. 



Let ai = amperes field on saturation curve correspond- 

 ing to V+CiRi and a 2 = amperes field on the synchronous 

 impedance curve corresponding to C. 



The amperes field required to produce normal rated 

 voltage with full load on the generator will be 



a. 3 =- 



Let the voltage on the saturation curve corresponding 

 to a s = Vi. 



Then the per cent regulation = ^ 



If it is desired to calculate the regulation of the machine 



7 

 at any power-factor, then C becomes r~ an d #3 = 



\a 2 i+ a 2 2-f2aia 2 sin 6 when 8 is the angle of which the 

 per cent power-factor is the cosine. 



[115] 



