Two-level coordinated controllers for robust inter-area oscillation damping considering impact of local latency

Abstract

Local latency adversely affects the stabilising performance of damping controllers especially in the two-level control scheme. By considering both wide area and local latencies, this study presents the two-level coordinated control which consists of wide area centralised and local controls of power oscillation damper (POD) and power system stabiliser (PSS) for robust power oscillation damping. The PODs are equipped with the doubly fed induction generator (DFIG) wind turbine, the solar photovoltaic generator (SPV), and the static VAR compensator (SVC). The centralised PODs of DFIG, SPV, SVC, and the centralised PSSs act as the primary damping controllers. When the communication failure occurs, the local PODs of such devices and the local PSSs are activated and used as the backup damping controllers. To achieve the damping performance and robustness, the parameters of centralised and local controllers are individually optimised based on the worst scenarios determined by the lowest damping ratio of target inter-area oscillation modes. Study results in New England and New York IEEE 68-bus system demonstrate that the proposed two-level coordinated controllers are superior to the conventional two-level controllers in terms of damping performance and robustness against various operating conditions