Unified Compensation for Network Latency in Synchrophasor Based System Control

In the real-time application of synchrophasor technology for wide-area damping controllers (WADCs), the remote signals from phasor measurement units (PMUs) can be impacted by variable delays, which can also lead to package drops. These network latencies vastly deteriorate the low-frequency oscillation-damping performance of WADCs, especially for data-driven based, model-free adaptive WADCs (MFA-WADCs). This paper presents a unified compensation approach for the variable delay and package drop. For compensating the variable delay in the PMU signals, an adaptive-probabilistic delay compensator (A-PoDC) is proposed. The uniqueness of the proposed A-PoDC is that it can provide compensation for diverse patterns of delay variations. Moreover, a new nonlinear methodology for package drop compensation is proposed, which uses the technique of dynamic linearization and pseudo partial derivative (DL-PPD) for estimating the dropped package. The advantage of the proposed nonlinear DL-PPD methodology is that it produces improved estimation over the linear methodology for burst-drops (continuous streak of package drops). Rigorous analysis is carried out to observe the effect of variable delay and package drops on the damping performance of MFA-WADCs. It is shown that with the proposed compensation techniques, the damping performance of MFA-WADCs improves over the customary compensation techniques.