Abstract:
ifydro electric generators are uøuclly locc!ted at P distance from the load- centres and are frequently required to excite }t. V. Lines on no load. A long trans-mission line couetitutee v wily P. pure c,peoitive lord so the generc'tor has to supply m l;rge KVAR output at a most zero P.P. Lording.
It is true that her load due to energizing the line is only a matter of few mutes but it is rn unavoidable transition-period end as such is extrenely important from operating point of view*
the fundi ental dr wbio is that since on zero ?.P. ledtng the aramr tune ampere turns m gnotise in the annie sense e s the abet WU01 npereturrn, tie voltrge has n tend rucy to rise. the ezoitr t on of the machine undtr such a condition Is to be reduced to s very low value* Lturally the problem comes so to whet is the lowest limit of excitation so that the
machine runs stable.
On commercial power systems, the l .r er ma,ohines are synchronous type, these include