Optimal capacitor placement by Enhanced Bacterial Foraging Optimization (EBFO) with accurate thermal re-rating of critical cables

Abstract

Optimal capacitor placement can significantly aid the control of the steady-state performance of a power system. During both normal and contingency operation in an existing network operating with future loading scenarios, some power lines have overloading and some buses have violations in their voltages. Optimal capacitor has the ability to solve these problems by controlling the voltage profile and then affecting on the power flows. In the simulated network, there are some cases where optimal placement on its own cannot sufficiently reduce power flows in some underground cables, even though it does dramatically reduce the degree of overloading. Enhanced Bacterial Foraging Optimization (EBFO) is incorporated optimally criteria for capacitors placement with sizing. That to enhance the performance of the power network in normal operation and during contingencies involving transmission line outages. The lines that are still overloaded are then evaluated with a comprehensive transient cable rating algorithm developed to see whether an accurate thermal re-assessment of the cable installations and loading will yield higher allowable load flows compared to the original ratings, which were based on conventional steady-stage rating techniques. The paper thus integrates the optimal capacitor placement and sizing with an accurate thermal evaluation of the cables that exceed their steady-state thermal limit to achieve a complete solution of all the system problems. This integrated approach is proposed for an actual realworld 110kV sub-transmission network.