In order to reflect

evaluate and improve the domestic supercritical unit's ability of participating in grid frequency regulation under different load conditions

the mathematical models of these supercritical thermal power units under different loadconditions were established

according to the lumped parameter method.Thus

the change rules of key parameters of these units under varying load conditions were obtained.On this basis

the control system models which are suitable for supercritical units were built.The frequency regulation dynamic simulation under different load conditions was carried out by using Simulink of the Matlab software

which demonstrated the effectiveness of the supercritical unit load frequency models.The results show that these models provide a platform which can improve and evaluate the unit's ability of participating in the grid frequency control under different load conditions.