Wide-area damping control system design with multi-HVDC based on state space model identification and geometric index

The traditional damping controller design method is difficult to adapt to the complex operating conditions, and may lead to poor damping effect due to improper control signal selection. A wide-area multi-HVDC (High Voltage Direct Current) damping controller design method is proposed based on auto regressive exogenous power system state space model identification. First, a low-order power system state space model with HVDC signal as input and AC transmission power as output is identified using auto regressive exogenous (ARX) model. Then, the geometric index of different input signals to the dominant oscillation mode can be calculated to select the best loop for HVDC supplementary controller. Finally, controller parameters are calculated by phase compensation method. The proposed method is able to reflect the actual operation condition of the power system, and takes the controllability of different types of signals to the dominant oscillation modes into consideration. The simulation results demonstrate that the proposed method can identify the dominant oscillation mode of the AC/DC system accurately so that the best control signal can be selected to improve the system damping efficiently.