Simulation Study on 1 000-MW Unit Speed Rise During Load Shedding

Load shedding is the worst operation scenario for large turbo-generator sets, which will increase rotor speed rapidly and threaten the safety of units greatly. In this paper, the maximum speed rise of a 1 000-MW unit is simulated with Simulink, and quantitative analysis on the influence of reheat steam volume time constant and rotor time constant on the dynamic characteristics of the governing system is performed. Combined with the on-line test data, the fast cut back (FCB) condition is simulated with the speed rise estimated.