38 CONSTANT- VOLTAGE TRANSMISSION 



In view of the advantages described in this chapter 

 of a system which is comparatively new as far as regards 

 commercial applications, it may be stated as a general 

 conclusion that not enough synchronous motors are in 

 use and that their application could well be increased 

 to a great extent. The right place to control the voltage 

 of a transmission line or net- work is at the receiving sta- 

 tions. This must be done by synchronous machines, 

 and the help of customers may be enlisted for attaining 

 this result. The tendency of transmission-line design 

 should, therefore, be to build lines of heavier conductors, 

 at lower voltages, or for longer distances, and at the 

 frequency of 60 cycles, and to hold the voltage constant 

 at all points by means of synchronous phase modifiers. 



SUMMARY OF CHAPTER VI 



Advantages of constant- voltage transmission: 



1 . Steady voltage. 



2. Steadier frequency in small water-power plants. 



3. Lower total cost where voltage is less than about 

 1,000 volts per mile. The low voltage per mile may be 

 caused by extensions, city conditions, corona, or a large 

 number of substations. 



4. Overloads are better handled. 



5. Large conductors reduce cost of towers and land. 



6. Wide spacings and large conductors extend corona 

 limit. 



7. Increase in economical distance of transmission. 



8. Better protection, due to high reactance. 



9. Tendency to use 60 cycles. 



10. The method can be gradually adopted. 



