Power Systems

An interconnected 50 Hz power system consists of one area with three turbine-generator units rated 1000, 750, and 500 MVA, respectively. The droop of each unit is 5% based on its own rating.Initially, each unit is operating at half its own rating. The system load suddenly increases by 200 MW. Determine (a) the per unit area frequency response characteristic on a 1000 MVA system base, (b) the steady state drop in area frequency, and (c) the increase in turbine mechanical power output of each unit. Assume that the reference power setting of each turbine-generator remains constant. Neglect losses and the dependence of load on frequency