Design of robust power oscillation damping controller for large-scale PV plant

Large-scale photovoltaic (PV) plants are becoming a reality in many countries. Studies suggest that the large-scale PV plants can have either a positive or negative influence on power system oscillation, which depends on many factors, including their location and sizes. Given the fact that these plants cannot be located in their ideal location for placement in power system, it is important to consider designing controllers for flawless integration. In this paper, a minimax Linear Quadratic Gaussian (LQG) based power oscillation damper (POD) for large-scale PV plant is proposed for oscillation damping. As a benchmark system for oscillatory stability analysis, the two-area test system is used to demonstrate the system performance with the designed controller. The robustness of the designed controller is verified under different operating conditions by eigenvalue analysis and non-linear power system simulation. Simulation results demonstrate that the proposed controller for PV plant improves the damping of inter-area mode for a wide range of operating conditions.