Naser Taheri - Faculty Member, Department of Electrical Engineering, Technical and Vocational University (TVU), Tehran, Iran

This paper presents the establishment of linearized Phillips-Heffron model of a power system installed HVAC parallel-connected with a Back to Back High Voltage Direct Current based voltage source converter (BtB VSC HVDC) The use of the supplementary controllers of a BtB VSC HVDC to damp low frequency oscillations in a weakly connected system is considered. The potential of the BtB VSC HVDC supplementary controllers to enhance the dynamic stability is evaluated using damping function. The problem of supplementary damping controller based VSC-HVDC system is formulated as an optimization problem according to the time domain-based objective function which is solved using imperialist competitive algorithm (ICA). Unique designs of the HVDC supplementary controller based on ICA method are appraised. The impressiveness of the proposed controllers on damping low frequency oscillations is verified through eigenvalue analysis and non-linear time simulation under various disturbance conditions of over a wide range of loading.

VSC HVDC; Power System Stability; Imperialist Competitive Algorithm; Supplementary Damping Controller.