CHAPTER XII 



WORKING METHODS OF CALCULATION 



A BETTER argument for the constant- voltage method 

 of control than general statements or examples of typi- 

 cal or actual transmission lines is to estimate for the 

 line in which one is most interested, the benefit to be 

 obtained from installing synchronous motors. This esti- 

 mation cannot be properly made by merely using the 

 calculations which are usual for varying-voltage lines. 

 Thus, it is not consistent to calculate the regulation of 

 the line between full load and no load, since the power- 

 factor is not a fixed quantity. So also, the benefits from 

 the synchronous motors are not best shown by calcu- 

 lating the amount by which they can raise the power- 

 factor of the load, since the benefit given to the trans- 

 mission system by the synchronous motors by controlling 

 the voltage is generally of much greater value than the 

 benefit given by raising the power-factor. Although it 

 is possible to operate a transmission line with a small 

 number of synchronous motors and with voltage varia- 

 tion, probably the best results will be obtained by in- 

 stalling enough synchronous motors so that they can be 

 depended on to hold the voltage constant at all parts of 

 the line for the range of load which the line will normally 

 carry. The working methods of calculation which will 

 be described will be based on this latter condition. 



Working methods of calculation should, if possible, 

 conform to the following conditions: The results to be 



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