Abstracto

SPEED CONTROLLER DESIGN FOR STEAM TURBINE

Rekha Rajan, Muhammed Salih. P, N. Anilkumar

A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Because the turbine generates rotary motion it is particularly suited to be used to drive an electrical generator. The control of a turbine with a governor is essential, as turbines need to be run up slowly to prevent damage and some applications (such as the generation of alternating current electricity) require precise speed control. Uncontrolled acceleration of the turbine rotor can lead to an over speed trip, which causes the nozzle valves that control the flow of steam to the turbine to close. If this fails then the turbine may continue accelerating until it breaks apart, often catastrophically. The application of PID (proportional integral derivative) controller span from small industry to high technology industry. Tuning the parameters of a PID controller are very important in PID control. Ziegler and Nichols proposed the well-known Ziegler-Nichols method to tune the coefficients of a PID controller. This tuning method is very simple, but cannot guarantee to be always effective. This thesis investigates the effectiveness of different controllers for the speed control of Tandem compound single reheat steam turbine. The speed of a Tandem compound single reheat steam turbine is controlled using the proposed MPC (model predictive control) controller. Then the results of the comparison of the proposed controller with the traditional PID controller and fuzzy PID controllers were also presented in this work. According to the simulation results in MATLAB, show that the proposed MPC can improve the robustness and small overshoot and fast response compared to the conventional PID and fuzzy PID. In the area of turbine speed control the faster response to research stability, the better is the result for the plant.