SYNCHRONOUS MOTORS 67 



49. At the end of a 3-phase transmission line which has a 

 resistance of 0.62 ohm and a reactance of 0.64 ohm per conductor 

 there is a synchronous motor whose armature windings are con- 

 nected in Y and have an effective resistance of 0.172 ohm and a 

 synchronous reactance of 2.12 ohms per phase. The rotational 

 losses of the motor are 17.2 kw. and may be assumed constant. 



When instruments in the generating station indicate that the 

 transmission line is receiving 780 kw. at 2250 volts and a power 

 factor of 0.88 (leading), what is the output of the motor? What 

 is the line voltage at the motor? 



50. A 3-phase transmission line has a resistance of 12.6 ohms 

 and a reactance of 16.4 ohms per conductor. The generating 

 station which delivers energy to this line maintains a constant 

 line potential difference of 14,000 volts. At the end of the line 

 there is a synchronous motor whose armature windings are 

 connected in Y and have an effective resistance of 1.52 ohms 

 and a synchronous reactance of 37.4 ohms per phase. The 

 rotational losses of this motor are 36.8 kw. and may be assumed 

 constant. When the motor is delivering 2000 h.p. and the 

 excitation voltage is adjusted to its greatest value of 16,700 

 volts what is the terminal voltage of the motor? At what 

 power factor is the motor operating? 



