

DETAILED STUDY OF OPERATION WITH NORMAL LOAD 75 



Finally, the cost of the energy used by the synchronous motors will be 

 (in francs) 



'' ........ (32) 



Numerical Example. Let us apply the preceding formulas to a 

 particular case. 



Assume a transmission of 500 k.w. to a distance of 24.75 kilo- 

 meters with 5000 volts at the receiving end, and a loss of 10 per cent in 



*; line. 

 Suppose it be desired to effect complete compensation by means 

 synchronous motors running without load. These motors must 

 >roduce a reactive leading current 



;'= I w tan </>. 



;t us suppose, moreover, that the active current of the motors, when 

 running without load, is 



Since we have 



I I = VP+f= \/J 2 +(/ w tan 



find 



. 7 W tan (> 



and 



V 101 

 w tan (f> 



vo-99 



Formula (28) gives 



p2 436.36 francs ($87.27). 



The voltage at the receiving end being 5000 volts, and the loss in 

 the line 10 per cent, the initial voltage must be 



o= =555 volts - 

 0.9 



Let us assume the cost of the generators and motors to be 

 p Q =p l =i 00 francs ($20) per kilovolt-ampere. 



