Interconnected system load-frequency control

Abstract

I F ALL TIE LINES were of ample capacity and stations under automatic control were well distributed geographically, there would be no need for tie line control except where required by contract interchange schedules. With the large scale advent of system interconnections and the necessity for more efficient operation, the tendency is to use frequency control biased by tie line load rather than frequency control only.The most common type of frequency control responds to instantaneous frequency difference with corrective impulses readjusting the prime mover speed level setting at a rate at least approximately proportional to the deviations from standard frequency. The frequency-responsive device for this type of equipment is usually an a-c bridge circuit or sometimes a pendulum-type clock in which corrective signals can be sent out for each swing of the pendulum.To obtain the advantage of smoother and less rapid prime mover gate or valve operation under automatic FREQUENCY COMPARATOR STANDARD FREQUENCY SOURCE HSV UNDER-VOLTACE| AND FREO. RELAYS DIFFERENTIAL ΗΠΖΉ UNDER-VOLTACEJ ANO FREO. RELAYS hP BUS SELECTOR 115 V 3» .