Benefits of Fast Cut Back function of thermal generating units in constructing self-healing grids

This paper investigates the benefits of Fast Cut Back (FCB) function of thermal generating units in the self-healing control context. The FCB function enables a generating unit to reduce its output down to the auxiliary power level within seconds. The output can later be restored to normal level promptly without cold start process. This ability can provide dispatchers additional measures in both the emergency control and the restorative control. In this paper, the model of FCB function generating units is established. The benefits of the FCB function in system restoration context are described. Case studies are presented to show: 1) FCB function can be used to maintain generation balance in controlled separation; 2) FCB function reduces the restoration time in the blackstart stage.