Abstrait

The Influence of Three-Phase Auto-Reclosure of Transmission Line on the Dynamic Stability of Power Systems

Onuegbu JC, Ezennaya SO, and Onyedikachi S

For a functional power system, the influence of automatic re-closure on the dynamic stability was ascertained by comparing calculated coefficients of system reserves during auto re-closure and without auto re-closure. It is only successful re-closure that was considered using double circuit power line and unsymmetrical short circuit. At the end of the work, a diagram was drawn to illustrate the pick-up area Ap and the retardation area Ar. For the calculation of the pick-up, retardation and then the coefficient of dynamic stability, there is also the need to find the re-closure angle δr and the re-closure time tr of the affected part. The dependence of re-closure angle on the re-closure time was tabulated. At the end of the investigation, coefficient of reserve of static stability kst at both normal regime and after short circuit regime was compared and found to have ensured higher stability when equipped with auto-re-closure. Lastly, the graph of switch-off angle limit δlim versus switch off time limit tlim was plotted and the result corresponded to the expected parameters.