Wide-Area Protection of Power Transmission Network without Utilizing External Network Model and Synchronized Phasor Measurement

Abstract

Wide-area protection of electric power transmission networks against faults was the main motivation behind the invention of synchronized phasor measurements. However, global positioning system (GPS) signal loss and synchronization errors on the one hand and variability of external network parameters on the other hand have prohibited utilization of wide-area protection of transmission network. This paper introduces a novel approach for wide-area protection in order to address the above-mentioned problems. By utilizing the measurements provided by phasor measurement units (PMU) located at border substations of the internal protected network, the proposed approach will be independent of external network parameters. Moreover the proposed formulation avoids using phase angle of PMU measurements, as opposed to existing methods that are vulnerable to loss or incorrect value of even one of phase angles of voltage/current synchrophasors. Another advantage of the proposed approach is avoidance of zero-sequence network parameters as well as identifying the faulted line regardless of fault type and its resistance. Simulation studies for the 9-bus Western Systems Coordination Council (WSCC) confirm high accuracy of the proposed approach in identifying the faulted transmission line.

Keywords

• least-squares estimation
• wide-area protection
• fault
• transmission line
• phasor measurement units (pmu)