scholarly journals Transient stability enhancement in the presence of optimally placed D-FACTS

Author(s):  
Omar Kamil Dahham Alazzawi ◽  
Mustafa Ahmed Nayyef ◽  
Yasir Abdulhafedh Ahmed

<span lang="EN-US">The power flow in power system can be controlled in an effective method by using FACTS devices through transmission lines. Distributed FACTS represent a new way to overcome these drawbacks. They are cost-effective, light weighted, higher performance and minimization of environmental impact. They are placed in a distribution method and in selected lines in the network according to line flow stability indices based on load flow calculations. In this paper, distributed static series compensator (DSSC) is used in order to attain the required power flow control by modifying the line reactance. They are installed directly on the present H.V transmission lines and as a result does not require H.V insulation. The load flow analysis has been carried using mat lab and the simulation for the purpose of stability by using Power World Simulator software. The results show an enhancement in stability performances of the system over the conventional controllers. </span>

Load Flow Analysis helps in error free operation of power system and also useful in forecasting the required equipment for expansion of the system. By forecasting the magnitude of the supply required along with effects caused by single or multiple defects in the system and calculating the magnitude of errors, it is very easy to compensate them using various techniques with minimum cost and effort. It means before installation the favorable sites and size of the infrastructure used are determined to maintain the power factor in the system. Here Power Flow Analysis is performed using Newton Raphson method. This method is used in solving power flow studies of various number of busesunder various conditions. In any network there will be undesired rise or drop or dissipation of voltage. Voltage instability decreases the efficiency of the system and also damages the equipment used. Hence voltage instability analysis is performed and magnitude of the instability is calculated and compensated using various techniques. Here we performed Load Flow Analysis on a 5bus system and Voltage Instability Analysis is also performed to the same with necessary outputs.[7]


2005 ◽  
Vol 42 (4) ◽  
pp. 369-382 ◽  
Author(s):  
T. Yalcinoz

This paper presents a software package developed in Matlab for teaching power systems analysis and operation. The software package is used to support and enhance power engineering education at both undergraduate and postgraduate levels. The application programs in this package include fault analysis, load flow analysis, transient stability, economic dispatch, unit commitment and load forecasting. All modules of the package are independent of each other. The students or researchers can make copies of the software to study and can modify any module of the package.


2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Ademola Abdulkareem ◽  
T. E. Somefun ◽  
C. O. A. Awosope ◽  
O. Olabenjo

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.


In this paper calculations are made to find out the power flow regulation capabilities of Unified Power Flow Controller (UPFC) in load flow analysis with loads which are voltage dependent. New equations for load flow analysis are developed that includes the models of voltage sensitive loads and voltage sources model of UPFC. Newton Raphson algorithm is used to solve the power flow equations of the network. UPFC voltage source model when included in the power equations has unique advantages over other modeling approaches. Analysis is done for two types of Loads. In the first analysis Constant current, Constant Power and Constant Impedance type of loads are examined. In the second analysis Composite loads are analyzed. The results of analysis on standard 5 bus system is presented here as a case study.


Author(s):  
Ajith M ◽  
Dr. R. Rajeswari

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.


With the ever increasing demand of power, the major concern that has aroused is the problem of voltage instability. Due to voltage instability several major power system failures and blackouts occur. Voltage stability thus becomes a necessity. For this FACTS devices like SVC, STATCOM, etc. are used. Load Flow analysis and Continuation Power Flow Analysis is done to identify the weak buses and FACTS devices are installed in these weak buses to enhance the voltage stability. This paper presents a network formulation of IEEE 30 Bus test system using MATLAB and PSAT software and then comparing the effect of SVC and STATCOM for voltage stability enhancement.


2018 ◽  
Vol 8 (3) ◽  
pp. 2963-2968 ◽  
Author(s):  
M. L. Tuballa ◽  
M. L. S. Abundo

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.


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