Voltage stability analysis and loadability estimation by using SCADA data: A case study of Electricite Du Lao transmission system

This paper presents a preliminary examination of voltage stability in the context of enhancing the transmission system of Laos Electricity (EDL) Central 1. Real SCADA data from the EDL database are used to evaluate common stability indices, namely the Fast Voltage Stability Index (FVSI), Line Stability Factor (LQP), and Line Stability Index (Lmn). The weakest bus and the most sensitive line are determined by ranking the stability indices. Furthermore, the sensitivity of the bus and the load capability of the line are assessed. The stability analysis is conducted under different load conditions, and the results are compared with actual interruption data. The case study identifies substations No. 5 and No. 8, along with the corresponding lines Phontong–Donekoy and Naxaythong–Pontong, as the most vulnerable areas in the central 1 region. Improving the load capability of these lines is critical to increasing the stability of the EDL Central 1 system.