OPERATION OF SYNCHRONOUS MOTORS. HUNTING 119 



Taking x= we will have 



2 U ! r i + x 2 tan 2 <f>' 



The curves in Fig. 59 represent C w as a function of x, when the 

 nstant ~ is taken as unity, and when tan is given values equal 

 5 and 10. 



0.05 



It is seen that the torque C w increases rapidly, at first, with the 

 speed, and then decreases more slowly with a maximum 



__ 

 tan</>' 



2 tan 



To bring back the motor to a speed near, that of synchronism, 

 it would be necessary to exert a mechanical force (torque) near that 

 which corresponds to x i , or 



i.e., the same as would be required to make the alternator rotate when 

 short-circuited upon itself. 



2) When once co^ is near oj\, the first term is no longer negligible. 

 The integral can no longer be evaluated except by supposing a>2 to be 

 constant within the limits of integration, i.e., during a great number of 

 periods. 



