Synchronized phasor data based energy function analysis of power transfer paths

Many large interconnected power systems such as the US eastern interconnection and the US western power system are characterized by many power transfer paths with high loading. Disruptions of these transfer paths frequently lead to increased loading on neighboring transfer paths, which themselves become less secure and could cause further disruptions. State estimators have limited performance under large system disruptions, because of low sampling rates and potentially poor solution quality due to topology errors. Furthermore, disruptions in external power systems cannot be readily seen by control room operators because most state estimators only use reduced models for external systems. A system of well-placed phasor measurement units (PMUs) that provide voltage and current magnitude and phase at a high sampling rate can provide useful system dynamic security information. In this paper we apply energy function analysis using phasor data to monitor the dynamic status of power transfer paths. The ideas are illustrated for a power transfer path using actual PMU data in the US western power system