Employing novel performance indices in robust design of PSS-POD controller to enhance dynamic stability of multi-machine power system

In this paper, integral of time multiplied squared error (ITSE), integral of squared time multiplied squared error (ISTSE), and integral of squared time multiplied error squared (ISTES) performance indices are applied in coordinated design problem of power system stabilizer (PSS) and thyristor controlled series capacitor (TCSC) based power oscillation damping (POD) controller. Employing these competent indices can help in suppressing the electromechanical (EM) oscillations more effectively than commonly employed integral of time multiplied absolute error (ITAE) index, since they have larger powers of time and error that can affect the settling time and peak error of dynamic responses, respectively. The coordinated design is formulated as an optimization problem in which the controller parameters are adjusted simultaneously via particle swarm optimization (PSO) algorithm by minimizing proposed indices in which some operating conditions are considered to guarantee robust design. Eigenvalue analysis and time domain simulations are performed in MATLAB/SIMULINK environment on 2 area 4 machine (2A4M) power system over different disturbances and operating conditions. Results show that superior enhancement in damping of EM oscillations is obtained by employing proposed indices. Meantime, a comparative study among results of proposed indices is done.