Reactive power optimization in power system

Abstract

There is a growing concern in power systems about reactive power operation and planning in recent decades since the reactive power mismanagement is the main cause for increased power loss, reduced power transfer capability violation of voltage magnitude limit and stability limit of the network The secured and economic operation of power system solely depends on the optimal flow of reactive power in the network Reactive Power Optimization RPO is a complex multivariable nonlinear problem with mixed number of continuous and discrete variables having nonlinear constraints and is a sub class of optimal power flow problem The control parameters are generator set points, tap ratios of transformer and new capacitor bank values The main objective of the RPO is to minimize transmission line losses while maintaining newlineconstant voltage profile and enhancing the voltage stability limit without violating the physical and operating limits This nonlinear optimization nature of RPO problem is one of the most challenging tasks This objective has to be achieved while satisfying both equality and inequality constraints. Even though classical gradient based algorithms are computationally faster to solve this problem but it lacks in handling this non convex problem with discrete control variable This enforces the need for meta heuristic algorithms to handle such problems This thesis introduces a novel technique which is known as Self Balanced Differential Evolution SBDE algorithm to achieve the objectives The supremacy and effectiveness of the proposed technique is tested with IEEE 30 bus system IEEE 57 bus system and IEEE 118 bus system under normal operating condition and stressed condition For decades researchers are showing their interest in optimizing several objectives at the same time newline newline