scholarly journals Voltage Stability Evaluation in the Nigeria 44 Bus Grid Network using Modal Analysis

2021 ◽  
pp. 80-89
Author(s):  
E. N. Aneke ◽  
B. E. Ibekwe ◽  
J. C. Iyidobi ◽  
E. N. C. Okafor
Keyword(s):  
Modal Analysis ◽  
Voltage Stability ◽  
Negative Real Part ◽  
Load Flow ◽  
Voltage Profile ◽  
Steady State Mode ◽  
Voltage Level ◽  
Transmission Grid ◽  
Grid Network ◽  
Ieee Standard

This paper focused on the application of modal analysis method to determine the voltage stability of the Nigeria 44 bus 330kV transmission grid network and to determine the network’s weakest buses. Modal method calculates the smallest eigenvalue and all the associated eigenvectors of the reduced Jacobian matrix, JR using steady state mode. The network model was developed in PSAT-MATLAB and load flow was performed on the network. Results and analysis showed that the Nigeria 44 Bus grid network was found to be unstable as the modal analysis revealed the presence of eigenvalue with a negative real part. Gombe, Damaturu and Yola buses were also discovered to be the vulnerable buses since their voltage profile fell below the IEEE standard voltage level of (0.95-1.05) pu. Yola bus was spotted as the weakest bus based on the analysis of the participating factors.

scholarly journals Voltage Stability Analysis of an Interconnected Power System Considering Varied Output of Wind Power Plants

2021 ◽  
Vol 56 (3) ◽  
pp. 111-123
Author(s):  
Muhammad Bachtiar Nappu ◽  
Ardiaty Arief ◽  
Ainun Maulidah
Keyword(s):  
Power Plant ◽  
Power System ◽  
Wind Power ◽  
Power Plants ◽  
Voltage Stability ◽  
Wind Power Plant ◽  
Voltage Profile ◽  
Interconnected Power System ◽  
Wind Power Plants ◽  
Ieee Standard

A sound power system must have voltage values at all buses that do not exceed the tolerance limit of ± 5% with small power losses. Voltage instability can be caused by interference or sudden power generation outage from the system. Indonesia's Southern Sulawesi power system has been interconnected with wind power plants located in Sidrap Regency and Jeneponto Regency. Wind speed energy used by wind power plants to generate electricity vary and not always constant. Hence, this can cause fluctuations and produce varied outputs that will affect the voltage profile and stability of the Southern Sulawesi interconnection system. Therefore, it is essential to assess the voltage stability of the Southern Sulawesi power system after the integration of Sidrap and Jeneponto WPPs. First, this study analyzes the voltage profile of the Southern Sulawesi interconnection system voltage after integrating the Sidrap wind power plants and Jeneponto Wind Power Plant during the peak day load and peak night load. Second, the study assesses the voltage stability with a varied output power of both Sidrap and Jeneponto Wind Power Plant. After integrating Sidrap and Jeneponto Wind Power Plants, the results showed that the voltage values at all system buses are stable and within the IEEE standard (between 0.95 p.u. and 1.05 p.u.). In addition, the voltages of the Southern Sulawesi power system with various outputs of both WPPs are still stable and within the IEEE standard.

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 Improvement the voltage stability margin of Iraqi power system using the optimal values of FACTS devices

2021 ◽  
Vol 11 (2) ◽  
pp. 984
Author(s):  
Ghassan Abdullah Salman ◽  
Hatim G. Abood ◽  
Mayyadah Sahib Ibrahim
Keyword(s):  
Power Systems ◽  
Power System ◽  
Voltage Stability ◽  
Stability Margin ◽  
Voltage Collapse ◽  
Voltage Profile ◽  
Heavy Load ◽  
Transmission Grid ◽  
Facts Devices ◽  
Voltage Stability Margin

The detection of potential voltage collapse in power systems is essential to maintain the voltage stability in heavy load demand. This paper proposes a method to detect weak buses in power systems using two stability indices: the voltage stability margin factor (dS/dY) and the voltage collapse prediction index (VCPI). Hence, the paper aims to improve the voltage stability of Iraqi transmission grid by allocating FACTS devices in the optimal locations and optimal sizes. Two types of FACTS are used in this paper which are Thyristor controlled series compensator (TCSC) and static var compensator (SVC). The objective function of the problem is fitted using particle swarm optimization (PSO). The proposed method is verified using simulation test on Diyala-132 kV network which is a part of the Iraqi power system. The results observed that improvement the voltage stability margin, the voltage profile of Diyala-132 kV is increased and the power losses is decreased.

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

scholarly journals A new meta-heuristic pathfinder algorithm for solving optimal allocation of solar photovoltaic system in multi-lateral distribution system for improving resilience

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Varaprasad Janamala
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Optimal Allocation ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Voltage Profile ◽  
Pv System ◽  
Solar Photovoltaic System ◽  
The Impact

AbstractA new meta-heuristic Pathfinder Algorithm (PFA) is adopted in this paper for optimal allocation and simultaneous integration of a solar photovoltaic system among multi-laterals, called interline-photovoltaic (I-PV) system. At first, the performance of PFA is evaluated by solving the optimal allocation of distribution generation problem in IEEE 33- and 69-bus systems for loss minimization. The obtained results show that the performance of proposed PFA is superior to PSO, TLBO, CSA, and GOA and other approaches cited in literature. The comparison of different performance measures of 50 independent trail runs predominantly shows the effectiveness of PFA and its efficiency for global optima. Subsequently, PFA is implemented for determining the optimal I-PV configuration considering the resilience without compromising the various operational and radiality constraints. Different case studies are simulated and the impact of the I-PV system is analyzed in terms of voltage profile and voltage stability. The proposed optimal I-PV configuration resulted in loss reduction of 77.87% and 98.33% in IEEE 33- and 69-bus systems, respectively. Further, the reduced average voltage deviation index and increased voltage stability index result in an improved voltage profile and enhanced voltage stability margin in radial distribution systems and its suitability for practical applications.

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.

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.

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