scholarly journals Stability issues in presence variable distributed generation into radial distribution network

2018 ◽  
Vol 218 ◽  
pp. 01005 ◽  
Author(s):  
Rahman Yuli Asmi ◽  
Agus Siswanto ◽  
Irwan Mahmudi
Keyword(s):  
Distributed Generation ◽  
Voltage Stability ◽  
Reactive Power ◽  
Load Condition ◽  
Stability Index ◽  
Before And After ◽  
Voltage Deviation ◽  
Bus Voltage ◽  
The Stability ◽  
The Impact

Related to environmental issues resulting from the use of traditional energy sources, drive usage of renewable energy is increasing. Changes in the structure of the network will certainly affect the changes in voltage stability. In this paper, discuss the impact of the stability after distributed generation penetration whose its output intermittent relatively. The simulation based PSAT software and tested into IEEE 30 bus system. Observation of voltage deviation and SVSI-index on some load buses in conditions before and after integration of wind generation. Load condition is a very determining factor of bus voltage stability index. This relates to the active power and reactive power needs that must be injected by DG penetration.

Optimization of Real Power Loss and Voltage Stability Index for Distribution Systems with Distributed Generation

2017 ◽  
Vol 33 ◽  
pp. 100-114 ◽  
Author(s):  
Mostafa Elshahed ◽  
Mahmoud Dawod ◽  
Zeinab H. Osman
Keyword(s):  
Genetic Algorithm ◽  
Distributed Generation ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Reactive Power ◽  
Optimization Problems ◽  
Stability Index ◽  
Mixed Integer ◽  
Voltage Profile ◽  
Voltage Stability Index

Integrating Distributed Generation (DG) units into distribution systems can have an impact on the voltage profile, power flow, power losses, and voltage stability. In this paper, a new methodology for DG location and sizing are developed to minimize system losses and maximize voltage stability index (VSI). A proper allocation of DG has to be determined using the fuzzy ranking method to verify best compromised solutions and achieve maximum benefits. Synchronous machines are utilized and its power factor is optimally determined via genetic optimization to inject reactive power to decrease system losses and improve voltage profile and VSI. The Augmented Lagrangian Genetic Algorithm with nonlinear mixed-integer variables and Non-dominated Sorting Genetic Algorithm have been implemented to solve both single/multi-objective function optimization problems. For proposed methodology effectiveness verification, it is tested on 33-bus and 69-bus radial distribution systems then compared with previous works.

Swarm-Intelligence-Based Optimal Placement and Sizing of Distributed Generation in Distribution Network

2018 ◽  
pp. 29-48 ◽  
Author(s):  
Mahesh Kumar ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Pandian Vasant ◽  
Luqman Hakim Rahman
Keyword(s):  
Distributed Generation ◽  
Radial Distribution ◽  
Distribution System ◽  
Voltage Stability ◽  
Reactive Power ◽  
Distribution Network ◽  
Stability Index ◽  
Pso Algorithm ◽  
Distribution Networks ◽  
Optimal Placement

In the distribution system, distributed generation (DG) are getting more important because of the electricity demands, fossil fuel depletion and environment concerns. The placement and sizing of DGs have greatly impact on the voltage stability and losses in the distribution network. In this chapter, a particle swarm optimization (PSO) algorithm has been proposed for optimal placement and sizing of DG to improve voltage stability index in the radial distribution system. The two i.e. active power and combination of active and reactive power types of DGs are proposed to realize the effect of DG integration. A specific analysis has been applied on IEEE 33 bus system radial distribution networks using MATLAB 2015a software.

scholarly journals Siting and Sizing of DG in Medium Primary Radial Distribution System with Enhanced Voltage Stability

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sanjay Jain ◽  
Ganga Agnihotri ◽  
Shilpa Kalambe ◽  
Renuka Kamdar
Keyword(s):  
Distributed Generation ◽  
Radial Distribution ◽  
Distribution System ◽  
Voltage Stability ◽  
Reactive Power ◽  
Voltage Profile ◽  
Power Losses ◽  
Radial Distribution System ◽  
Power Loss Reduction ◽  
The Impact

This paper intends to enumerate the impact of distributed generation (DG) on distribution system in terms of active as well as reactive power loss reduction and improved voltage stability. The novelty of the method proposed in this paper is the simple and effective way of sizing and siting of DG in a distribution system by using two-port Z-bus parameters. The validity of the method is verified by comparing the results with already published methods. Comparative study presented has shown that the proposed method leads existing methods in terms of its simplicity, undemanding calculation procedures, and less computational efforts and so does the time. The method is implemented on IEEE 69-bus test radial distribution system and results show significant reduction in distribution power losses with improved voltage profile of the system. Simulation is carried out in MATLAB environment for execution of the proposed algorithm.

Optimum Location of Spvg to Enhance Voltage Stability Using Static Techniques

2020 ◽  
Vol 23 (2) ◽  
pp. 49-58
Author(s):  
Melat K. Abdulla ◽  
Lokman H. Hassan
Keyword(s):  
Power Systems ◽  
New England ◽  
Power Flow ◽  
Voltage Stability ◽  
Load Condition ◽  
Vital Role ◽  
Heavy Load ◽  
The Stability ◽  
The Impact ◽  
Photovoltaic Generators

Solar Photovoltaic Generators (SPVGs) play a great and vital role in providing clean and enough energy to meet power loads. However, SPVGs integration on power systems increase power grid problems. It will lead to different problems including disturbance of the grid, instability of the voltage and swings of the power. The impact of SPVG on the voltage stability of the system is studied in this paper. The best location of SPVG is obtained using three static techniques. Power flow and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under nominal load condition respectively. On other hand, Continuation Power Flow (CPF) and the Q-V curve techniques are used to identify the weakest buses and test the stability of the system under heavy load condition respectively. The proposed techniques are apllied to the New England 39-bus standard system under various loading conditions. The results reveal that choosing a proper location for the SPVG will improve the voltage stability of the system. In addition, connecting the SPVG at the nearest bus to the weakest bus provides better performance than when it connected to the weakest bus.

scholarly journals Enhancement of Voltage Stability by Using SVC for 30-Bus Power System

2019 ◽  
Vol 4 (2) ◽  
pp. 128-136
Author(s):  
Dara Hama Amin
Keyword(s):  
Power System ◽  
Voltage Stability ◽  
Reactive Power ◽  
Sensitivity Factor ◽  
Voltage Sensitivity ◽  
Voltage Profile ◽  
Voltage Level ◽  
Facts Devices ◽  
Before And After ◽  
The Stability

Voltage stability refers to maintaining the value of the voltage in all busses of the electric network at a steady level (initial operating point) during any sudden disturbance. Voltage instability may happen due to an increase in the demand of the load or in case of any change in the reactive power, thus, the system will go into uncontrollable and unstoppable decline in the voltage level. The effect of Static Var Compensator (SVC) on voltage stability is discussed in the paper, as well as the improvement of the voltage profile. Usually, SVC and FACTS devices were used for enhancing the voltage level profile and so the stability. Choosing the optimal location for the FACTS devices is essential due to its expensive costs. This paper used sensitivity factor to helpful to determine the most correct placement of FACTS devices in the system. Simulations are performed on Kurdistan Region 30-bus Power System using MATLAB-PSAT tool. As a result, the voltage of all 30 buses calculated. Based on the “voltage sensitivity factor”, the nominated weak buses has been marked which are suitable for placing the FACTS devices in order to improve the limits of the voltage stability of the system. Moreover, depending on the obtained optimal locations, a full analysis of the voltage and powers for the system has applied in two cases, before and after placing SVC respectively which is result in notable stability improvement and losses reduction.

scholarly journals Voltage stability in distribution network

2020 ◽  
Author(s):  
◽  
Sboniso Brutus Masikana
Keyword(s):  
Voltage Stability ◽  
Reactive Power ◽  
Distribution Network ◽  
Research Work ◽  
Electric Energy ◽  
Load Flow ◽  
Voltage Profile ◽  
Voltage Instability ◽  
Bus Voltage ◽  
The Impact

Voltage stability studies and to maintain the flat voltage profile is quite important in order to maintain the healthy operation of electric power network as well as to provide the quality and cheap electric energy to the modern power users. Further with the advancement of power electronics technologies and its application to design flexible alternating current transmission devices (FACTS) have made it easier to alleviate the voltage stability problem in a quicker and cheaper way in the modern DNs. Therefore, this research work shows an attempt to investigate and solve the problem of voltage instability in the distribution network (DN) with the help of FACTS. All buses and lines are calculated in terms of voltage stability index (VSI) and to identify the optimal location of FACTS. The bus or line with minimum voltage profile in terms of VSI are more sensitive to the voltage collapse and it may further lead to blackouts. Hence, the FACTS are permanently installed at the weakest point to enhance voltage profile and improve the voltage stability in the DN. The present study is tested on standard IEEE-15 bus DN and application results are shown to verify the feasibility of the present studies for DN. The beauty and future promise of UPFC in power quality improvement was authenticated on the IEEE-15 bus DN carried out using MATLAB software tool, five different scenarios were considered by increasing the load up to 40% at an interval of 10% from its nominal operating load. With the aim of determining the impact of UPFC on bus voltage and system losses, the load flow analysis was contributed on each scenario with and without UPFC placement in the DN. After UPFC placement there was a significant enhancement of voltages of all busses as well as weakest bus voltage jump from 0.5750 to 0.9750 p.u. and shifting that bus as well as system from voltage instability to stable zone. The active and reactive power loses were decrease by 9.83% and 27.27% that fulfil the beauty of the UPFC installation in the DNs as well as it promise to mitigate the voltage instability problem of the modern DNs

Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)

2012 ◽  
Vol 61 (2) ◽  
pp. 239-250 ◽  
Author(s):  
M. Kumar ◽  
P. Renuga
Keyword(s):  
Power System ◽  
Voltage Stability ◽  
Reactive Power ◽  
Optimization Technique ◽  
Optimal Solution ◽  
Stability Index ◽  
Test System ◽  
Unified Power Flow Controller ◽  
Voltage Profile ◽  
Voltage Stability Index

Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)Transmission line loss minimization in a power system is an important research issue and it can be achieved by means of reactive power compensation. The unscheduled increment of load in a power system has driven the system to experience stressed conditions. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission System (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. The optimal value of compensating devices requires proper optimization technique, able to search the optimal solution with less computational burden. This paper presents a technique to provide simultaneous or individual controls of basic system parameter like transmission voltage, impedance and phase angle, thereby controlling the transmitted power using Unified Power Flow Controller (UPFC) based on Bacterial Foraging (BF) algorithm. Voltage stability level of the system is defined on the Fast Voltage Stability Index (FVSI) of the lines. The IEEE 14-bus system is used as the test system to demonstrate the applicability and efficiency of the proposed system. The test result showed that the location of UPFC improves the voltage profile and also minimize the real power loss.

scholarly journals To study the voltage stability limits of distributed generation using induction machine in distribution networks

2013 ◽  
Vol 16 (2) ◽  
pp. 43-53
Author(s):  
Chuong Trong Trinh ◽  
Anh Viet Truong ◽  
Tu Phan Vu
Keyword(s):  
Distributed Generation ◽  
Power Distribution ◽  
Power Flow ◽  
Voltage Stability ◽  
Reactive Power ◽  
Induction Machine ◽  
Distribution Networks ◽  
Distribution Grid ◽  
Asynchronous Machine ◽  
Asynchronous Machines

There are now a lot of distributed generation (DG) using asynchronous machines are connected to power distribution grid. These machines do not usually generate reactive power, even consume reactive power, so they generally affect the voltage stability of whole power grid, and can cause instability in itself it is no longer balanced by the torque to work. In this paper, we investigate the voltage stability problem of the asynchronous machine of wind turbines used in power distribution networks. From the static model of the asynchronous machine, this paper will apply the pragmatic criteria to analysis the voltage stability of the asynchronous machine based on the results of the power flow in power distribution network.

scholarly journals Neural Entrainment Meets Behavior: The Stability Index as a Neural Outcome Measure of Auditory-Motor Coupling

2021 ◽  
Vol 15 ◽  
Author(s):  
Mattia Rosso ◽  
Marc Leman ◽  
Lousin Moumdjian
Keyword(s):  
Outcome Measure ◽  
Pathological Condition ◽  
Brain Activity ◽  
Behavioral Outcomes ◽  
Stability Index ◽  
Behavioral Measures ◽  
Neural Entrainment ◽  
Entrainment Effect ◽  
The Stability ◽  
The Impact

Understanding rhythmic behavior in the context of coupled auditory and motor systems has been of interest to neurological rehabilitation, in particular, to facilitate walking. Recent work based on behavioral measures revealed an entrainment effect of auditory rhythms on motor rhythms. In this study, we propose a method to compute the neural component of such a process from an electroencephalographic (EEG) signal. A simple auditory-motor synchronization paradigm was used, where 28 healthy participants were instructed to synchronize their finger-tapping with a metronome. The computation of the neural outcome measure was carried out in two blocks. In the first block, we used Generalized Eigendecomposition (GED) to reduce the data dimensionality to the component which maximally entrained to the metronome frequency. The scalp topography pointed at brain activity over contralateral sensorimotor regions. In the second block, we computed instantaneous frequency from the analytic signal of the extracted component. This returned a time-varying measure of frequency fluctuations, whose standard deviation provided our “stability index” as a neural outcome measure of auditory-motor coupling. Finally, the proposed neural measure was validated by conducting a correlation analysis with a set of behavioral outcomes from the synchronization task: resultant vector length, relative phase angle, mean asynchrony, and tempo matching. Significant moderate negative correlations were found with the first three measures, suggesting that the stability index provided a quantifiable neural outcome measure of entrainment, with selectivity towards phase-correction mechanisms. We address further adoption of the proposed approach, especially with populations where sensorimotor abilities are compromised by an underlying pathological condition. The impact of using stability index can potentially be used as an outcome measure to assess rehabilitation protocols, and possibly provide further insight into neuropathological models of auditory-motor coupling.

Improved Pseudo-Gradient Search Particle Swarm Optimization for Optimal Power Flow Problem

2016 ◽  
pp. 177-207 ◽  
Author(s):  
Jirawadee Polprasert ◽  
Weerakorn Ongsakul ◽  
Vo Ngoc Dieu
Keyword(s):  
Particle Swarm Optimization ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Voltage Stability ◽  
Stability Index ◽  
Gradient Search ◽  
Fuel Cost ◽  
Swarm Optimization ◽  
Optimal Power ◽  
Voltage Deviation

This paper proposes an improved pseudo-gradient search particle swarm optimization (IPG-PSO) for solving optimal power flow (OPF) with non-convex generator fuel cost functions. The objective of OPF problem is to minimize generator fuel cost considering valve point loading, voltage deviation and voltage stability index subject to power balance constraints and generator operating constraints, transformer tap setting constraints, shunt VAR compensator constraints, load bus voltage and line flow constraints. The proposed IPG-PSO method is an improved PSO by chaotic weight factor and guided by pseudo-gradient search for particle's movement in an appropriate direction. Test results on the IEEE 30-bus and 118-bus systems indicate that IPG-PSO method is superior to other methods in terms of lower generator fuel cost, smaller voltage deviation, and lower voltage stability index.

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