A new non-linear model of steam turbine unit for dynamic analysis of power system

Model simulations are becoming more important in dynamic power system analyses as our increasing dependence on electricity supply. However, the general steam models often show some disadvantages in dynamical cases. No enough attention is paid to the non-linear relationships between flow rate and pressure differences. The paper puts forwards a new nonlinear turbine model taking the nonlinearities into consideration. Disturbances of a 600MW power plant are recorded for the model verification. The main parameters are obtained by using an parameter identification method based on genetic algorithm (GA) and the system output are estimated based on the presented model. The measured data and the simulated results are in favorable agreement, indicating the accuracy of the non-linear model.