A quantitative method to determine ICT delay requirements for wide-area power system damping controllers

This paper presents a quantitative method to determine delay requirements of the information and communication technology (ICT) system supporting wide-area power oscillation damping (WAPOD) controllers. An allowable time delay for the ICT infrastructure named “equivalent time delay (ETD)” is defined. The ETD is calculated by numerically comparing the damping behavior of the system when local input signals (LI) and remote input signals (RI) are used in the damping controller. The use of a WAPOD is only justified when its response outperforms that of a controller using local inputs. Therefore, the total time delay in the control loop must be below the calculated ETD. As such, the ETD serves as a design criteria to determine ICT latency requirements. The selection of an effective RI signal can be carried out by considering the maximum delays (ETDs) of different wide-area measurements. A damping improvement ${rm ETD}^{x∼%}$ has been proposed using the same methodology indicating a minimum outperformance of the remote signals. The proposed method is demonstrated using the well-known Klein-Rogers-Kundur multi-machine power system and the Vietnamese power system model.