scholarly journals Modelling of Electric Grid to Enhance Generated Power Evacuation

2021 ◽  
pp. 163-173
Author(s):  
Donald Eloebhose ◽  
Nelson Ogbogu
Keyword(s):  
Power Plants ◽  
Short Circuit ◽  
Flow Analysis ◽  
Load Flow ◽  
System Stability ◽  
Contingency Analysis ◽  
Load Flow Analysis ◽  
Electric Power Grid ◽  
Three Phase ◽  
Rivers State

The study of evacuation of power from the power plants in Rivers State Nigeria, connecting to the 330kV transmission network of the Transmission Company of Nigeria (TCN). The Power World Simulator Educational version was used in the modelling and simulation of the electric power grid. The study of load flow analysis, short circuit, transient and N-1 contingency analysis and their effect on the 330 kV/132kV transmission bus connected to the existing power plants in Rivers State Nigeria namely; Rivers IPP (180MW), Afam III (265.6MW), Afam IV & V (351.00 MW) and Afam VI G. S (650.00 MW) was carried out. From the short circuit study, it is observed that when a bus is faulted with a 3-phase fault, the three-phase voltages of the system drastically become zero in all the phases. The other buses of the network experience an increase in voltage and all the buses fed have the same effect as the bus under fault, though the effect is felt more on the buses. However, with the introduction of substation splitting at Afam III and ongoing Afam IV substations, the short circuit level will be reduced by 15%; leading to improvement in the overall system stability.

scholarly journals Evaluation of the Impact of High Penetration Levels of PV Power Plants on the Capacity, Frequency and Voltage Stability of Egypt’s Unified Grid

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 552 ◽  
Author(s):  
Hamdy Sultan ◽  
Ahmed Diab ◽  
Oleg Kuznetsov ◽  
Ziad Ali ◽  
Omer Abdalla
Keyword(s):  
Power Plants ◽  
Voltage Stability ◽  
Short Circuit ◽  
Flow Analysis ◽  
Frequency Stability ◽  
Load Flow ◽  
Transmission Network ◽  
Load Flow Analysis ◽  
High Penetration ◽  
The Impact

In this paper, the impact of integrating photovoltaic plants (PVPs) with high penetration levels into the national utility grid of Egypt is demonstrated. Load flow analysis is used to examine the grid capacity in the case of integrating the desired PVPs and computer simulations are also used to assess the upgrading of the transmission network to increase its capacity. Furthermore, the impact of increasing the output power generated from PVPs, during normal conditions, on the static voltage stability was explored. During transient conditions of operation (three-phase short circuit and outage of a large generating station), the impact of high penetration levels of PVPs on the voltage and frequency stability has been presented. Professional DIgSILENT PowerFactory simulation package was used for implementation of all simulation studies. The results of frequency stability analysis proved that the national grid could be maintained stable even when the PVPs reached a penetration level up to 3000 MW of the total generation in Egypt. Transmission network upgrading to accommodate up to 3000 MW from the proposed PV power plants by 2025 is suggested. In addition, analysis of voltage stability manifests that the dynamic behavior of the voltage depends remarkably on the short circuit capacity of the grid at the point of integrating the PVPs.

scholarly journals Power system analysis and integration of the proposed Nigerian 750-kV power line to the grid reliability

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Ademola Abdulkareem ◽  
T. E. Somefun ◽  
C. O. A. Awosope ◽  
O. Olabenjo
Keyword(s):  
Transmission Lines ◽  
System Analysis ◽  
Flow Analysis ◽  
Ring Structure ◽  
Load Flow ◽  
Maximum Efficiency ◽  
Contingency Analysis ◽  
Power System Analysis ◽  
Load Flow Analysis ◽  
Critical Areas

AbstractThe present situation of power generation in Nigeria obviously represents a challenge to our ability for rethinking the delivery of energy at maximum efficiency. Previous research on the existing Nigerian 330-kV network grid, recommended that the network be transformed from radial to ring because of high losses inherent in it and the voltage insecurity. In this study, the existing 330-kV network was reconfigured based on the identified regions mapped out for upgrade to form a ringed 750-kV super grid. The bus voltages of some of the buses in the existing 330-kV were upgraded to 750-kV and new transmission lines added to create an integrated super grid with a ring structure as compared to the radial nature of the existing 330-kV grid. These proposed buses have been selected for upgrade based on the fact that they are positioned in critical areas within the topology of the grid that transforms the existing radial structure to a ring one. The method is also cheaper than making the entire network a 750-kV system. Load-flow analysis was carried out on the existing 330-kV Nigerian Grid and the proposed Nigerian 750-kV integrated into the existing grid using Newton–Raphson algorithm. The results analysis of the new network revealed a significant reduction of 30.2% power loss. This was validated using the code-based MATLAB and Power World Simulation model-based software. Contingency analysis was also carried out on both grids using the Power World Simulator. The study revealed that the 750-kV super grid was able to mitigate the losses experienced on the existing grid significantly with better voltage profiles in all the buses. It also revealed that the new network (330-kV and 750-kV integrated) performed better to the single line contingency analysis with less violations occurring and no unsolvable cases.

scholarly journals A new method to incorporate three-phase power transformer model into distribution system load flow analysis

2021 ◽  
Vol 10 (3) ◽  
pp. 262
Author(s):  
Rudy Gianto ◽  
Purwoharjono Purwoharjono
Keyword(s):  
Distribution System ◽  
Power Transformer ◽  
Flow Analysis ◽  
Test System ◽  
Load Flow ◽  
Simple Method ◽  
System Load ◽  
Load Flow Analysis ◽  
Three Phase ◽  
Transformer Model

This paper proposes a new and simple method to incorporate three-phase power transformer model into distribution system load flow (DSLF) analysis. The objective of the present work is to find a robust and efficient technique for modeling and integrating power transformer in the DSLF analysis. The proposed transformer model is derived based on nodal admittance matrix and formulated by using the symmetrical component theory. Load flow formulation in terms of branch currents and nodal voltages is also proposed in this paper to enable integrating the model into the DSLF analysis. Singularity that makes the calculations in forward/backward sweep (FBS) algorithm is difficult to be carried out. It can be avoided in the method. The proposed model is verified by using the standard IEEE test system.

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 Operational Impact of RES Penetration on a Remote Diesel-Powered System in West Papua, Indonesia

2018 ◽  
Vol 8 (3) ◽  
pp. 2963-2968 ◽  
Author(s):  
M. L. Tuballa ◽  
M. L. S. Abundo
Keyword(s):  
Transient Stability ◽  
Short Circuit ◽  
Flow Analysis ◽  
Load Flow ◽  
Circuit Breakers ◽  
Transmission Grid ◽  
Load Flow Analysis ◽  
Remote Island ◽  
Tidal Turbine ◽  
Short Circuit Analysis

When a new power source connects to the distribution or transmission grid, an assessment of its impact is necessary. Technical studies must assess the possible effects of a proposed expansion, reinforcement or modification to evaluate the possible incidents that may occur. Typically, the calculations or analyses done are load flow, short-circuit, and transient stability. The possible renewable energy (RE) sources are determined first. The details of the existing electrical system, including the specifications for the elements used, are obtained and logical assumptions are utilized for those that are not known. The load flow analysis in the considered case revealed that the RE presence reduces diesel generation. The 119 kW PV array and the 54 kW tidal turbine displace most diesel generation: 22% of Gen 4 and 21.8% of Gen 5. The diesel-solar system brought the diesel generation down by 20.05% of Gen 4 and 20% of Gen 5. The diesel-tidal combination lessened the diesel generation by 1.92% of Gen 4 and 1.83% of Gen 5. Short-circuit analysis alerts indicating the operating percentages of the circuit breakers that are beyond their interrupting ratings are presented. The transient stability analysis depicts that RE sources affect the existing system and appear to be putting in more stress. The studied systems are not transient-stable based on the results. While it is relatively simple to plan to put up renewables in remote island systems, there are many factors to consider such as the possible impacts of the RE sources.

scholarly journals Constant Voltage Model of DFIG-Based Variable Speed Wind Turbine for Load Flow Analysis

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8549
Author(s):  
Rudy Gianto
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power Factor ◽  
Power Plants ◽  
Flow Analysis ◽  
Load Flow ◽  
Constant Voltage ◽  
Load Flow Analysis ◽  
Proposed Model ◽  
Doubly Fed

At present, the penetration of wind-driven electric generators or wind power plants (WPPs) in electric power systems is getting more and more extensive. To evaluate the steady state performances of such power systems, developing a valid WPP model is therefore necessary. This paper proposes a new method in modeling the most popular type of WPP, i.e., DFIG (doubly fed induction generator)-based WPP, to be used in power system steady state load flow analysis. The proposed model is simple and derived based on the formulas that calculate turbine mechanical power and DFIG power. The main contribution of the paper is that, in contrast to the previous models where the DFIG power factor has been assumed to be constant at unity, the constant voltage model proposed in this paper allows the power factor to vary in order to keep the voltage at the desired value. Another important contribution is that the proposed model can be implemented in both sub-synchronous and super-synchronous conditions (it is to be noted that most of the previous models use two different mathematical models to represent the conditions). The case study is also presented in the present work, and the results of the study confirm the validity of the proposed DFIG model.

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