Vibration prevention of steam turbine by mixing the main demand with vibration signal

Abstract

Steam turbine (ST) in power plant is a complex mechanical system. ST is protected from many dangerous situations such as thrust, eccentricity, over frequency and vibration in the bearing. All these situations will cause the turbine to go into the reject area and will cause the turbine to shutdown during the generation stage. This paper will present a new control method by simulation that uses both instantaneous vibration values and generated power of the turbine to reduce the vibration values automatically and hence, protect the turbine. We proposed and designed two electronic circuits using MATLAB-Simulink simulation that will trigger the protection system upon reaching the selected vibration values, which is based on ISO10816-2. Result shows the generated power has successfully decreases as expected after the vibration exceeds the threshold. The system will go into shutdown if the first stage protection system fails to decrease the vibration value which is a basic protection mechanism inherent in all steam turbines.