Shishir Dixit

Optimal Placement of Shunt Facts Devices Using Heuristic Optimization Techniques: An Overview

This paper presents a literature survey on applications of shunt connected Flexible Alternating Current Transmission Systems (FACTS) such as Static VAR Compensator (SVC), Static Synchronous Compensator (STATCOM) for enhancement of power system performance parameters like reactive power compensation, minimization of the real power losses, voltage stability improvement, and also to provide the flexible operation & better controllability etc. The paper is beneficial for understanding applications of shunt FACTS controllers for researchers to further study & research to implement it in various areas of power system as well. The paper also presents a review of various algorithms and analysis of various optimization techniques used for optimal location and sizing of SVC and STATCOM considering one and/or more than one objectives.

Optimal location and size of TCSC for voltage stability enhancement using PSO-TVAC

Maintaining Voltage stability is one of the most important issues in electrical power systems operation. Voltage instability is a major problem that occurs due to deficit of reactive power at load buses in power system under increased loading or during contingencies. Voltage stability of a power system can be improved using Flexible AC transmission systems (FACTS) controllers like thyristor controlled series compensator (TCSC), static var compensator etc. Like other FACTS controllers, TCSC is a costly device involving huge investment. Hence, it is important to find its optimal location and its size, in order to improve voltage stability in a power system. In this paper, Particle Swarm Optimization with time varying acceleration coefficients (PSO-TVAC) has been proposed to find out the optimal location and size of TCSC for voltage stability improvement of a power system. This paper considers line stability index (LSI) for determining the optimal location of TCSC. Line stability index provides information about the stability condition of a power system and its proximity to voltage collapse. The effectiveness of proposed method has been demonstrated on a standard IEEE 30-bus system.

Optimal placement of SVC for minimizing power loss and improving voltage profile using GA

Various problems occurring in the operation of emerging restructured power system networks can be solved up to some extent by using flexible AC transmission system (FACTS) devices. In the planning stage of installation of these devices, an exhaustive exploration is a must to acquire maximum benefit of these devices as these devices require huge capital investment. In this paper, Genetic Algorithm (GA) has been applied to find the optimal location of Static Var Compensator (SVC) so that, real power loss, voltage deviation and rating of SVC may be minimized considering the most critical contingencies. As a first step, contingency ranking has been performed to determine the most severe line outages by evaluating voltage performance index (VPI). Thereafter, GA has been applied to find the optimal location and size of SVC. The effectiveness of the proposed methodology is demonstrated on a standard IEEE 30-bus system.

Power flow analysis using fuzzy logic

The attributes of fuzzy theory have been successfully explored and implemented in this paper for performing the power flow analysis in a fuzzy environment. A fuzzy system is being proposed in this paper to solve power flow problem under different loading and under contingency conditions. Power flow analysis is carried out for computing bus voltage magnitude, voltage angle, real & reactive power of the system. The fuzzy system has many advantageous features such as optimized system complexity, control of power flow, control of non-linear system etc. The composition of the input variable for the proposed fuzzy logic based power flow method has been selected to emulate the solution process of a conventional power flow. The effectiveness of the fuzzy based power flow is demonstrated by computation of bus voltage magnitude & voltage angle for different loading condition & for single line outage contingencies in 3- bus and 6-bus systems

An Overview of Placement of TCSC for Enhancement of Power System Stability

Flexible Alternating Current Transmission Systems (FACTS) represents a vast development in the area of power system operation and control. This paper gives an overview about application of series connected Flexible alternating current transmission system (FACTS) for enhancement of power system performance like transfer stability, secure voltage profile and reduce the system losses etc. FACTS devices require huge capital investment. Therefore, heuristic techniques are used for optimal location and sizing of series FACTS controllers like Genetic Algorithm (GA), Particle Swarm Optimization (PSO) etc. This paper gives details of optimal placement and sizing of FACTS devices based on different evolutionary techniques which is used for minimization of transmission loss, enhancement of stability of power system. In this study one of the FACTS devices is used as a scheme for enhancement of power system stability. Proper installation of FACTS devices also results in significant reduction of transmission loss. In this review, TCSC is selected as the compensation device.

Optimal Location of SVC Considering Critical Contingency and Varying Load

The flexible Alternating Current transmission system (FACTS) may play a vital role in solving various problems of modern restructured power system networks, which have to operate under highly stressed conditions because of ever increasing demand of electric power. However, due to huge capital investment, an intensive investigation is required at planning stage to select optimal location and size of these devices to acquire maximum benefit of it. In this paper, Continuous Genetic Algorithm (CGA) based method is proposed for placement of Static Var Compensator (SVC) for minimizing real power loss, load bus voltage deviations and size of SVC. As a first step, contingency ranking is performed to determine the most severe line outages by evaluating voltage performance index (VPI) for both cases i.e. for base load condition and when load is varied randomly. Thereafter, Continuous Genetic Algorithm (CGA) has been applied to solve mixed continuous-discrete optimization problem. The optimization is carried out to find optimal location and size of SVC to minimize real power loss, load voltage deviation and rating SVC. The effectiveness of the proposed methodology is demonstrated on a standard IEEE 30-bus system.