Ganga Agnihotri

Hybrid butterfly based particle swarm optimization for optimization problems

One of the superior optimization algorithms amongst all earlier introduced algorithms is the particle swarm optimization algorithms. This paper introduces Butterfly Particle swarm optimization (BF-PSO) with some novel control parameters such as sensitivity of butterfly towards nectar by different means of communication and probability of the nectar presence. This new hybrid algorithm is based on the intelligent characteristics and behavior of butterfly during the process of food (nectar) search and mimics their intelligent network structures. Sensitivity and the probability of nectar, according to the degree of nodes is calculated using this new algorithm. By adding the effect of these modifications in the standard Particle Swarm Optimization (PSO), the algorithm performance and the ability to search optimum value of the Particle Swarm Optimization is improved. Finally, the results of applying the BF-PSO on benchmark functions are shown. The overall improvement in performances of the BF-PSO on the basis of the sensitivity of butterfly and probability of nectar source.

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.

Modeling of frequency domain control of shunt active power filter using MATLAB Simulink and Power System Blockset

This paper presents modeling and simulation of a shunt active power filter in frequency domain, using MATLAB and its tools Simulink and Power System Blocket. The proposed method offers many additional features over other methods. It attributes the responsibility of utility and customer at PCC. It provides an additional feature of compensation of either harmonics only, or the compensation of both harmonics and reactive power simultaneously, based on the desired capacity of the APF

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.

Performance Analysis of Grid Integrated Hydro and Solar Based Hybrid Systems

The renewable energy systems (RESs) are an attractive option to electrify the community as they are environment friendly, free of cost, and all-pervading. The efficiency of these energy systems is very low and can be improved by integrating them in parallel. In this paper, hydro (7.5 kW) and solar systems (10 kW) are taken as RESs and connected with the utility grid. Due to the intermittent nature of both the hydro and photovoltaic energy sources, utility grid is connected to the system for ensuring the continuous power flow. The hydro power generation system uses the self excited induction generator (SEIG) and converters. The AC/DC/AC converter is used as interface to connect the hydro turbine to the utility grid to adjust the generated voltage to the utility grid voltage. The solar generation system is the combination of PV array, boost converter, and solar inverter. The control of both the hydro and solar power plants is provided through the constant current controller. The analysis has been done to verify the existence of the proposed system. Results demonstrate that the proposed system is able to be put into service and can feed the community.

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

Power Management Strategy for Active Power Sharing in Hydro/PV/Battery Hybrid Energy System

Simulation and modeling of standalone DC linked hydro/PV/battery hybrid energy system (HES) and power management strategy (PMS) for identifying the active power sharing have been done. The performance analysis of the proposed HES and its power management strategy has been done using the simulink toolboxes of MATLAB software. The proposed system consists of 10 kW PV system, 7.5 kW hydro system, battery, and power condition unit. In some remote/rural areas, it is very difficult to satisfy the demand of electrical power throughout the year with the power grid. In such areas, the power requirement can be fulfilled by renewable energy system such as hydro or PV system. Either the hydro system or PV system is not capable of supplying power requirement throughout the year as both systems are intermittent. Hence, the judicious combination of hydro and PV system has been modeled for electrification. The power management strategy is modeled to manage the power flow of the energy systems and battery to fulfill the load demand. The presented results clearly show that the proposed HES and its control strategy are suitable for implementation in remote/rural areas.

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.

Impacts of the load models on optimal planning of distributed generation in distribution system

The optimal planning (sizing and siting) of the distributed generations (DGs) by using butterfly-PSO/BF-PSO technique to investigate the impacts of load models is presented in this work. The validity of the evaluated results is confirmed by comparing with well-known Genetic Algorithm (GA) and standard or conventional particle swarm optimization (PSO). To exhibit its compatibility in terms of load management, an impact of different load models on the size and location of DG has also been presented in this work. The fitness evolution function explored is the multiobjective function (FMO), which is based on the three significant indexes such as active power loss, reactive power loss, and voltage deviation index. The optimal solution is obtained by minimizing the multiobjective fitness function using BF-PSO, GA, and PSO technique. The comparison of the different optimization techniques is given for the different types of load models such as constant, industrial, residential, and commercial load models. The results clearly show that the BF-PSO technique presents the superior solution in terms of compatibility as well as computation time and efforts both. The algorithm has been carried out with 15-bus radial and 30-bus mesh system.