This paper presents a method in expansion planning of transmission systems using the AC optimal power flow (AC-OPF). The AC-OPF provides a more accurate picture of power flow in the network compared to the DC optimal power flow (DC-OPF) that is usually considered in the literature for transmission expansion planning (TEP). While the AC-OPF-based TEP is a mixed-integer nonlinear programming prob...

Stability is an important constraint in power system operation; the transient stability constrained optimal power flow (TSCOPF) has a considerable attention in recent years. The solution obtained from the conventional optimal power flow (OPF), which considers only the static constraints, does not guarantee transient stability in the system against possible contingencies such as line fault. In t...

In this study, a multiobjective optimization is applied to Optimal Power Flow Problem (OPF). To effectively achieve this goal, a Multiobjective Ant Lion algorithm (MOALO) is proposed to find the Pareto optimal front for the multiobjective OPF. The aim of this work is to reach good solutions of Active and Reactive OPF problem by optimizing 4-conflicting objective functions simultaneously. Here a...

Under the competitive environments, power companies may calculate optimal power flow (OPF) in many occasions: especially for such real time applications as contingency analysis and congestion management. However, caused by congestions, etc., it is not guaranteed that OPF has the feasible solution in every calculation case. This paper proposes a new optimal power flow calculation model applicabl...

Optimal Power Flow (OPF) is one of the main functions of Power Generation Operation and Control. It determines the optimal settings of generating units, bus voltage, and transformer tap and shunt elements in Power System with the objective of minimizing total production costs or losses while the system is operating within its security limits. The aim of this paper is to propose a methodology (G...

This paper presents a novel method to approximate the nonlinear AC optimal power flow (OPF) into tractable linear/ quadratic programming (LP/QP) based OPF problems that can be used for power system planning and operation. We derive a linear power flow approximation and include a convex reformulation of the power losses in the form of absolute value functions. We show three ways how we can incor...

In this paper a multi objective optimal power flow (OPF) is obtained by using BAT search algorithm (BAT) with Unified power flow controller (UPFC). UPFC is a voltage source converter type Flexible Alternating Current Transmission System (FACTS) device. It is able to control the voltage magnitudes, voltage angles and line impedances individually or simultaneously. UPFC along with BAT algorithm i...

This paper presents a new framework for the day-ahead reactive power market based on the uniform auction price. Voltage stability and security have been considered in the proposed framework. Total Payment Function (TPF) is suggested as the objective function of the Optimal Power Flow (OPF) used to clear the reactive power market. Overload, voltage drop and voltage stability margin (VSM) are inc...

Optimal power flow is an optimizing tool for operation and planning of modern power systems. This paper presents the solution of the optimal power flow (OPF) using particle swarm optimization (PSO). The main goal of this paper is to verify the viability of using PSO problem composed by different objective functions. This OPF problem involves the optimization of various types of objective functi...