TCSC based online adaptive control for improving damping in multimachine power system

Power systems are inherently prone to disturbances that result in poorly damped low frequency electromechanical oscillations. This paper presents an adaptive PID (APID) controller for improving oscillation damping capability of a Thyristor controlled series capacitor (TCSC). An adaptive supplementary control can set the control parameters of PID in an online mode responding to respective changes in system´s operating conditions. Control parameters are updated in real time by utilizing gradient descent method. Performance of proposed controller is investigated on two machine four bus system under diverse fault conditions. Nonlinear time domain simulation is made in MATLAB/Simulink and validation of proposed controller is made by its comparison with conventional PI controller. Results show clear eminence of proposed controller in improving transient stability of given system.