Coordinated control of thermal generating unit aiming at multi-machine power systems

Present coordinated controllers of thermal generating unit are mainly designed based on the simplified model of generating unit. In the simplified model, the dynamics of generator are omitted, and thus present controllers can not meet the requirements of various operating states in real multi-machine power systems. In this paper, integral model of generating unit (including the models of boiler, turbine and generator) is used to design coordinated controller. When designing controller, the security of grid frequency and the security of generating unit are weighed simultaneously. Meanwhile, the gain scheduling controller is used to design the new coordinated controller. The proposed controller can utilize the energy storage of generating unit flexibly, and on emergency state the stability of grid frequency could be strengthened at a small cost. The simulation results also demonstrate the validity of the proposed coordinated controller.