Control of tie-line power swings

THE object of this paper is to present the results of an analytical study of tie-line power control. This study was made as a logical development of the general subject of power system control. Previous work^1,2 has indicated the general requirements of the prime-mover speed governors and the desirability of supplementary control to insure proper load division, frequency, and time. The general requirements of supplementary controls are given in the companion paper³ by Crary and McClure. In most cases these controls are satisfactorily obtained as rather slow corrective adjustments to the speed-governor mechanisms, but for certain types of load a more active tie-line load controller, which will tend to suppress transient load swings also, may be required. An example of this is a rapidly varying load, such as a strip mill supplied from local generation as well as from a tie to a larger power system, in which it may be desirable to keep the load variations off the tie line as much as possible.