scholarly journals Implementation of a Dynamic Network Model of the Nigerian Transmission Grid for Investigations on Power System Stability

2019 ◽  
Author(s):  
Kosisochukwu Pal Nnoli
Keyword(s):  
Power System ◽  
Dynamic Models ◽  
Model Performance ◽  
Dynamic Network ◽  
Modern Society ◽  
Electrical Energy ◽  
Load Flow ◽  
System Stability ◽  
Power Network ◽  
Transmission Grid

Electricity is the backbone of any modern society and economy. Therefore, economic growth and an increase in social wealth of a country usually lead to an increase in demand for electrical energy especially for a country as Nigeria. As the population of Nigeria is increasing exponentially, there exists a need to make basic needs constantly available, for the wellbeing of the increasing population. This is possible through mechanization. Reliable and stable electricity supply is the surest means to this end. As a result, there is a need to constantly review the dynamics of the power system while more energy sources and loads are being added to the existing power network grid. This creates a demand for precise models for the corresponding network. In this paper, the power network system of the Nigerian transmission grid was implemented at normal operations to include the dynamic models to the corresponding network elements (i.e. generation Units based on their installed capacities and controllers). With the help of this model, stationary load flow calculations, as well as the network’s model performance in steady state was conducted. The network’s model performance in the case of load changes and fault operations was also carried out. These allowed for investigations on the stability status of the Nigerian transmission grid.

scholarly journals Improving Power Transmission System Stability in Nigerian using Statcom Device Controller

2019 ◽  
Vol 8 (12) ◽  
pp. 3623-3627
Keyword(s):  
Power System ◽  
Power Transmission ◽  
Simulation Analysis ◽  
Flow Simulation ◽  
Transmission System ◽  
Load Flow ◽  
System Stability ◽  
Static Synchronous Compensator ◽  
Power Transmission System ◽  
Voltage Limit

The instability of power transmission system in Nigeria is the concern of many individual and that is what this paper wants to address. The first stage was to analyze the effect of static synchronous compensator (STATCOM) on power transmission stability. In doing that, the three phase fault was introduced to the system at line 4-5. The Load flow simulation analysis was carried out according to IEEE 9 bus system. The power transmission system model was developed and simulated using MATLAB/SIMULINK software. The result of the simulation shows that Bus 5 was detected to violate the voltage limit of 0.95 < V< 1.05 p.u. having a voltage magnitude of 0.8875p.u. The per unit Voltage magnitude of power system with STATCOM and without STATCOM was calculated. From the result, the voltage magnitude without STATCOM was 0.8875p.u while that with STATCOM was 1.01p.u. The total active power Loss without STATCOM was 324.02MW while that with STATCOM was 322.53MW. Therefore the percentage of power system improvement is 0.23% when STATCOM was incorporated. Finally, Power transmission system improves when STATCOM was applied.

scholarly journals Improvement of bus voltage profiles of Nigerian power network in the presence of Static Synchronous Compensator (STATCOM) and Doubly Fed Induction Generator (DFIG)

2020 ◽  
Vol 39 (1) ◽  
pp. 228-237
Author(s):  
I.B. Anichebe ◽  
A.O. Ekwue
Keyword(s):  
Renewable Energy ◽  
Stability Analysis ◽  
Power System ◽  
Power Flow ◽  
Voltage Stability ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Load Flow ◽  
Energy Sources ◽  
Power Network

Frequent blackouts and unstable supply of electricity show that the  voltage instability problem has been one of the major challenges facing the power system network in Nigeria. This study investigates the voltage stability analysis of the Nigerian power network in the presence of renewable energy sources; FACTS device is used as a voltage controller. A 330kV, 28-bus power system network was studied using the PSS/E software-based Newton-Raphson load-flow technique. The results show that 10 out of the 28 buses had voltages lying below the statutory limit of 0.95 ≤ 1.05 p.u. The application of STATCOM and DFIG devices on two of the weakest buses restored the voltages to acceptable statutory limits. The total active and reactive power losses were reduced to 18.76% and 18.82% respectively. Keywords: Voltage stability analysis; Integration of renewable energy sources; FACTS controllers, Reactive Power, Power Flow.

scholarly journals Gauss-Seidel Method based Voltage Security Analysis of Distribution System

2018 ◽  
Vol 8 (1) ◽  
pp. 43
Author(s):  
Gagari Deb ◽  
Kabir Chakraborty
Keyword(s):  
Power System ◽  
Distribution System ◽  
Critical Line ◽  
Security Analysis ◽  
System Stability ◽  
Measurement Unit ◽  
Power Network ◽  
Radial Distribution System ◽  
Voltage Security ◽  
Base Data

Complexity of modern power network and Large disturbance results voltage collapse. So, voltage security analysis is important in power system. Indicators are helpful in voltage stability analysis, as they give information about the state of the system. In this paper a new indicator namely Distribution System Stability Indicator (DSSI) has been formulated using the information of Phasor Measurement Unit (PMU).The proposed indicator (DSSI) is tested on standard IEEE 33 bus radial distribution system. The suggested indicator is also applicable to the equivalent two bus system of a multi-bus power system. The proposed indicator is calculated for different contingent conditions at different system load configurations. The result of DSSI is verified with the standard indicator (VSI) which proves applicability of the proposed indicator. The bus voltages of all the buses at base loading and at maximum loading are evaluated for base data and for tripping of most critical line.

scholarly journals Load Flow Analysis in Hybrid AC-DC Transmission Network

2021 ◽  
pp. 617-624
Author(s):  
Ajith M ◽  
Dr. R. Rajeswari
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Short Circuit ◽  
Flow Analysis ◽  
Load Flow ◽  
System Stability ◽  
And Control

Power-flow studies are of great significance in planning and designing the future expansion of power systems as well as in determining the best operation of existing systems. Technologies such as renewables and power electronics are aiding in power conversion and control, thus making the power system massive, complex, and dynamic. HVDC is being preferred due to limitations in HVAC such as reactive power loss, stability, current carrying capacity, operation and control. The HVDC system is being used for bulk power transmission over long distances with minimum losses using overhead transmission lines or submarine cable crossings. Recent years have witnessed an unprecedented growth in the number of the HVDC projects. Due to the vast size and inaccessibility of transmission systems, real time testing can prove to be difficult. Thus analyzing power system stability through computer modeling and simulation proves to be a viable solution in this case. The motivation of this project is to construct and analyze the load flow and short circuit behavior in an IEEE 14 bus power system with DC link using MATLAB software. This involves determining the parameters for converter transformer, rectifier, inverter and DC cable for modelling the DC link. The line chosen for incorporation of DC link is a weak bus. This project gives the results of load flow and along with comparison of reactive power flow, system losses, voltage in an AC and an AC-DC system.

scholarly journals Impact of large photovoltaic power penetration on the voltage regulation and dynamic performance of the Tunisian power system

2020 ◽  
Vol 38 (5) ◽  
pp. 1774-1809
Author(s):  
Abdelaziz Salah Saidi
Keyword(s):  
Power System ◽  
Short Circuit ◽  
Dynamic Performance ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Voltage Regulation ◽  
Load Flow ◽  
Grid Systems ◽  
Transmission Grid ◽  
Photovoltaic Power

By the year 2023, the Tunisian power transmission grid has been projected to include photovoltaic pool of power of 937 MW, scattered throughout the whole landscape of the nation. This paper investigates high photovoltaic energy penetration impacts voltage regulation and dynamic performance of the grid. Load flow analysis is implemented to investigate the power system capability for the case of incorporating the desired photovoltaic power. Computer-based simulations have been used for evaluating the upgradation of the grid. Moreover, the study is based on bifurcation diagrams taking the photovoltaic generation as a bifurcation parameter and time response simulations to grid disturbances. Professional PSAT simulation toolbox has been used for the power flow simulation studies. Network- related faults like outage of photovoltaic farm event, three-phase short-circuit at a conventional bus, and voltage dip at the largest photovoltaic station have been considered. It is hoped that the results of the presented study would benefit Tunisian’s utility’s policies on integration of PV systems. Moreover, this comprehensive analysis and study will be a valuable guide for assessing and improving the performance of national grid systems of any other countries also, that gives the huge potential and need for solar energy penetration into the grid systems.

An Investigative Study on Impact of Frequency Dynamics in Load Modeling

2020 ◽  
Vol 01 (01) ◽  
Author(s):  
Musa Mohammed ◽  
◽  
Abubakar Abdulkarim ◽  
Adamu Sa’du Abubakar ◽  
Abdullahi Bala Kunya ◽  
...  
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Low Voltage ◽  
Model Performance ◽  
System Stability ◽  
Normal System ◽  
Area Network ◽  
Load Modeling ◽  
Feed Forward Neural Network ◽  
Load Model

Load modeling plays a significant impact in assessing power system stability margin, control, and protection. Frequency in the power system is desired to be kept constant, but in a real sense, it is not constant as loads continually change with time. In much literature, frequency dynamics are ignored in the formulation of load models for the basic assumption that it does not affect the models. In this paper, the composite load model was formulated with Voltage-Frequency Dependency (V-FD) on real and reactive powers and applied to estimate the load model. 2- Area network 4- machines Kundur test network was used for testing the developed model. The model was trained with measurements from a low voltage distribution network supplying the Electrical Engineering department at Ahmadu Bello University, Zaria. Both training and testing data were captured under normal system operation (dynamics). To evaluate the V-FD model performance, Voltage-Dependent (VD) model was examined on the same measured data. The work makes use of the Feed Forward Neural Network (FFNN) as a nonlinear estimator. Results obtained indicate that including frequency dynamics in modeling active power reduces the accuracy of the model. While in modeling reactive power the model performance improves. Hence, it can be said that including frequency dynamics in load modeling depends on the intended application of the model.

scholarly journals Multi-Agent Optimization for Residential Demand Response under Real-Time Pricing

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2867 ◽  
Author(s):  
Zhanle Wang ◽  
Raman Paranjape ◽  
Zhikun Chen ◽  
Kai Zeng
Keyword(s):  
Power System ◽  
Demand Response ◽  
Electricity Market ◽  
Energy Cost ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
System Stability ◽  
Optimization Approach ◽  
Model Case ◽  
Multi Agent

Demand response (DR) programs encourage consumers to adapt the time of using electricity based on certain factors, such as cost of electricity, renewable energy availability, and ancillary request. It is one of the most economical methods to improve power system stability and energy efficiency. Residential electricity consumption occupies approximately one-third of global electricity usage and has great potential in DR applications. In this study, we propose a multi-agent optimization approach to incorporate residential DR flexibility into the power system and electricity market. The agents collectively optimize their own interests; meanwhile, the global optimal solution is achieved. The agent perceives its environment, predicts electricity consumption, and forecasts electricity price, based on which it takes intelligent actions to minimize electrical energy cost and time delay of using household appliances. The decision-making action is formulated into a convex program (CP) model. A distributed heuristic algorithm is developed to solve the proposed multi-agent optimization model. Case studies and numerical analysis show promising results with low variation of the aggregated load profile and reduction of electrical energy cost. The proposed approaches can be utilized to investigate various emerging technologies and DR strategies.

scholarly journals Modelling of an Electric Power Grid for New Power Plant Evacuation

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Sunday Adetona ◽  
Emenike Ugwuagbo ◽  
Frank Okafor ◽  
Tolulope Akinbulire
Keyword(s):  
Power Plant ◽  
Power System ◽  
Electric Power ◽  
Transient Stability ◽  
Short Circuit ◽  
Power Grid ◽  
Load Flow ◽  
System Stability ◽  
System Component ◽  
Electric Power Grid

Injection of a new power system component into an existing power grid often cause change in the behaviour of the power grid to which it is injected. Therefore, forecasting possible unsafe condition(s) of the power grid using an efficient power study tool is essential; and, provision of necessary mitigation actions to ensure a reliable grid is important. This paper, therefore, presents evacuation study of a 400 MW power plant connecting to the 15 GW planned transmission network of the Transmission Company of Nigeria (TCN). The NEPLAN power system analytical software was used in the modelling and simulation of the electric power grid. In the research, load flow, short circuit, transient stability, and contingency analyses were performed on the case study. From the short circuit study, it is observed that if TCN network expansion program is fully implemented, the short circuit level will go beyond the existing switchgear ratings in major substations of the network. However, with the introduction of substation splitting at Omotoso and ongoing Ogijo substations, the short circuit level will be reduced by 15%; leading to improvement in the overall system stability. Keywords—Load flow, short circuit study, transient stability study, and contingency analysis

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