Optimizing Voltage Stability Limit and Real Power Loss in a Large Power System using Bacteria Foraging

An optimal allocation of transformer taps and reactive power injections at some selected locations is carried out with a view to maximize the voltage stability limit (VSL) of a multi machine power system, simultaneously with the objective of real power loss minimization. This issue is formulated as a non-linear equality and inequality constrained multi-objective optimization problem. A new evolutionary algorithm known as bacteria foraging is applied for solving, first the optimum settings of the transformer taps only and then with selected reactive power injections at some buses, so that the power system operates more securely achieving both the objectives.