CHAPTER VII 



HISTORY OF THE CONSTANT-VOLTAGE SYSTEM 



THE information perhaps most desired by any one 

 contemplating the adoption of the constant-voltage 

 method of control is a description of power systems 

 which have actually used synchronous motors for the 

 sake of the large economies described and have obtained 

 satisfactory and reliable operation. Power systems must 

 be excluded from this list of examples if they merely 

 employ large numbers of synchronous motors with fixed 

 rheostat setting, but do not continually adjust the exci- 

 tation so as to overcome directly, by these adjustments, 

 the variations hi line voltage from hour to hour. While 

 the list of veritable examples of power systems using the 

 principles of constant-voltage transmission is not long, 

 it is sufficiently large to show that the method is not 

 merely theoretical, but has been proved in actual prac- 

 tice to be commercially economical and advisable under 

 correct conditions. 



The information in this chapter regarding actual 

 instances of the use of the constant- voltage method, and 

 references to the method by technical writers, is not 

 complete, and is probably not in correct chronological 

 order, since it is based merely on various items appear- 

 ing in the electrical literature of the last few years. It 

 will be observed that at different times in the past have 

 the possibility and the profit of constant- voltage opera- 

 tion of transmission lines been suggested, though prob- 



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