

)ETAILED STUDY OF OPERATION WITH NORMAL LOAD 65 



a power-line, P 2 , two output-points, A 2 and A 1 '2, situated respect- 



ly at the right and at the left of the phase-line AiN; and let us project 

 on that line, at a. 



From what has already been seen, the lengths A 2 a and A 2 'a will 

 jresent the values of the reactive currents corresponding to the 

 outputs; but while the first, A 2 a, is lagging with respect to the 

 Drking current, which is equivalent to the effect of a self-induction 

 all of its objections, the second, A 2 'a, is leading, which is equivalent 



the effect of a condenser. 



We therefore see that for all values whose representative point is 

 'ed on the left of the phase-line A\N there will be a reactive leading 



ent. It is this current, equivalent to that of a condenser, which 



,bles the lagging reactive current to be neutralized, including the 



.gnetization-current necessary for various translating appliances, 



:h as induction-motors, transformers, induction-coils, etc., on the 



te portion of the circuit. 



As we shall see later, it is very easy to calculate these compensation- 

 phenomena with a view to their practical application. 



In studying the effects produced by the reaction of synchronous 

 motors, we should, at the outset, distinguish between two very dif- 

 ferent things, i.e., the load (current) on the line and the load (current) 

 on the generating station supplying that line. 



(i) Compensation with Respect to the Line or Circuit. Many 

 ordinary translating appliances, notably transformers, arc -lamps, and 

 especially induction-motors, have a power-factor, cos 0, which is 

 lower than unity, and which increases uselessly the heating of the con- 

 ductors of the distributing system cr of the line, in the case of a 

 simple transmission-system. [The loss of voltage in the line is likewise 

 increased in greater proportion than the current, in consequence of lag, as 

 the author has shown elsewhere. See articles on " Line-inductance for 

 Alternating Currents ", VEclairage Electrique. Oct., Dec., 1894.] 



The aim of the compensation sought should be to increase this 

 power-factor as much as possible, by producing the reactive currents 

 locally instead of transporting them over the line. 



The evaluation of these currents is not difficult, owing to the fact 

 that in the translating appliances just mentioned the magnetizing 



points situated on the left of the reference-line OY are those which produce a 

 leading current with respect to the voltage at the terminals. It is therefore on 

 the left of OF that tke motor plays the role of a condenser. 



