The electricity supply industry is undergoing a profound transformation worldwide. Market forces, scarcer natural resources, and an ever-increasing demand for electricity are some of the drivers responsible for such unprecedented change. Against this background of rapid evolution, the expansion programs of many utilities are being thwarted by a variety of well-founded, environment, land-use, and regulatory pressures that prevent the licensing and building of new transmission lines and electricity generating plants.
Introduction
Definition of FACTS system
Necessity of facts devices
Shunt connected controllers
Types of facts controllers
Shunt connected controllers
Benefits of FACTS
The concept of FACTS (Flexible AC Transmission System) refers to a family of power electronics based devices able to enhance AC system controllability and stability and to increase power transfer capability.
The design of the different schemes and configurations of FACTS devices is based on the combination of traditional power system components (such as transformers, reactors, switches, and capacitors) with power electronics elements (such as various types of transistors and thyristors).
Introduction
Definition of FACTS system
Necessity of facts devices
Shunt connected controllers
Types of facts controllers
Shunt connected controllers
Benefits of FACTS
The concept of FACTS (Flexible AC Transmission System) refers to a family of power electronics based devices able to enhance AC system controllability and stability and to increase power transfer capability.
The design of the different schemes and configurations of FACTS devices is based on the combination of traditional power system components (such as transformers, reactors, switches, and capacitors) with power electronics elements (such as various types of transistors and thyristors).
The concept of FACTS (Flexible Alternating Current Transmission System) refers to a family of power electronics-based devices able to enhance AC system controllability and stability and to increase power transfer capability.
The electricity supply industry is undergoing a profound transformation worldwide. Market forces, scarcer natural resources, and an ever-increasing demand for electricity are some of the drivers responsible for such unprecedented change. Against this background of rapid evolution, the expansion programs of many utilities are being thwarted by a variety of well-founded, environment, land-use, and regulatory pressures that prevent the licensing and building of new transmission lines and electricity generating plants.
High Voltage Direct Current technology has certain characteristics which
make it especially attractive for transmission system applications. HVDC
transmission system is useful for long-distance transmission, bulk power delivery and
long submarine cable crossings and asynchronous interconnections. The study of
faults is essential for reasonable protection design because the faults will induce a
significant influence on operation of HVDC transmission system. This paper provides
the most dominant and frequent faults on the HVDC systems such as DC Line-to-
Ground fault and Line-to-Line fault on DC link and some common types of AC faults
occurs in overhead transmission system such as Line-to-Ground fault, Line-to-Line
fault and L-L-L fault. In HVDC system, faults on rectifier side or inverter side have
major affects on system stability. The various types of faults are considered in the
HVDC system which causes due to malfunctions of valves and controllers, misfire
and short circuit across the inverter station, flashover and three phase short circuit.
The various faults occurs at the converter station of a HVDC system and
Controlling action for those faults. Most of the studies have been conducted on line
faults. But faults on rectifier or inverter side of a HVDC system have great impact on
system stability. Faults considered are fire-through, misfire, and short circuit across
the inverter station, flashover, and a three-phase short circuit in the ac system. These
investigations are studied using matlab simulink models and the result represented in
the form of typical time responses.
In the modern power system the reactive power compensation is one of the main issues, the transmission of active power requires a difference in angular phase between voltages at the sending and receiving points (which is feasible within wide limits), whereas the transmission of reactive power requires a difference in magnitude of these same voltages (which is feasible only within very narrow limits). The reactive power is consumed not only by most of the network elements, but also by most of the consumer loads, so it must be supplied somewhere. If we can't transmit it very easily, then it ought to be generated where it is needed." (Reference Edited by T. J. E. Miller, Forward Page ix).Thus we need to work on the efficient methods by which VAR compensation can be applied easily and we can optimize the modern power system. VAR control technique can provides appropriate placement of compensation devices by which a desirable voltage profile can be achieved and at the same time minimizing the power losses in the system. This report discusses the transmission line requirements for reactive power compensation. In this report thyristor switched capacitor is explained which is a static VAR compensator used for reactive power management in electrical systems.
Seminar Topic For Electrical and Electronics Engineering (EEE)
The concept of FACTS (Flexible Alternating Current Transmission System) refers to a family of power electronics-based devices able to enhance AC system controllability and stability and to increase power transfer capability.
The electricity supply industry is undergoing a profound transformation worldwide. Market forces, scarcer natural resources, and an ever-increasing demand for electricity are some of the drivers responsible for such unprecedented change. Against this background of rapid evolution, the expansion programs of many utilities are being thwarted by a variety of well-founded, environment, land-use, and regulatory pressures that prevent the licensing and building of new transmission lines and electricity generating plants.
High Voltage Direct Current technology has certain characteristics which
make it especially attractive for transmission system applications. HVDC
transmission system is useful for long-distance transmission, bulk power delivery and
long submarine cable crossings and asynchronous interconnections. The study of
faults is essential for reasonable protection design because the faults will induce a
significant influence on operation of HVDC transmission system. This paper provides
the most dominant and frequent faults on the HVDC systems such as DC Line-to-
Ground fault and Line-to-Line fault on DC link and some common types of AC faults
occurs in overhead transmission system such as Line-to-Ground fault, Line-to-Line
fault and L-L-L fault. In HVDC system, faults on rectifier side or inverter side have
major affects on system stability. The various types of faults are considered in the
HVDC system which causes due to malfunctions of valves and controllers, misfire
and short circuit across the inverter station, flashover and three phase short circuit.
The various faults occurs at the converter station of a HVDC system and
Controlling action for those faults. Most of the studies have been conducted on line
faults. But faults on rectifier or inverter side of a HVDC system have great impact on
system stability. Faults considered are fire-through, misfire, and short circuit across
the inverter station, flashover, and a three-phase short circuit in the ac system. These
investigations are studied using matlab simulink models and the result represented in
the form of typical time responses.
In the modern power system the reactive power compensation is one of the main issues, the transmission of active power requires a difference in angular phase between voltages at the sending and receiving points (which is feasible within wide limits), whereas the transmission of reactive power requires a difference in magnitude of these same voltages (which is feasible only within very narrow limits). The reactive power is consumed not only by most of the network elements, but also by most of the consumer loads, so it must be supplied somewhere. If we can't transmit it very easily, then it ought to be generated where it is needed." (Reference Edited by T. J. E. Miller, Forward Page ix).Thus we need to work on the efficient methods by which VAR compensation can be applied easily and we can optimize the modern power system. VAR control technique can provides appropriate placement of compensation devices by which a desirable voltage profile can be achieved and at the same time minimizing the power losses in the system. This report discusses the transmission line requirements for reactive power compensation. In this report thyristor switched capacitor is explained which is a static VAR compensator used for reactive power management in electrical systems.
Seminar Topic For Electrical and Electronics Engineering (EEE)
Project is designed to develop a FACTs (Flexible AC Transmission) by TSR (Thyristor Switch Reactance) used in two ways. Read more about this project here.
Flexible alternating current transmission systems (FACTs) technology opens up new opportunities for
controlling power flow and enhancing the usable capacity of present, as well as new and upgraded lines. These
FACTs device which enables independent control of active and reactive power besides improving reliability and
quality of the supply. This paper describes the real and reactive power flow control through a short transmission
line and then compensated short transmission line with different FACTs devices are used to selection of FACTs
devices for better reactive power compensation with change in line capacitance/shunt capacitance to observe
power flow. Computer simulation by MATLAB/SIMULINK has been used to determining better reactive power.
TCSC, STATCOM, UPFC and SSSC FACTs controller with different capacitance are tested for controlling
reactive power flow.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
USING SSSC & STATCOM --IMPROVE TRANSIENT STABILITY--P & Q OSICALLATIONSIJSRD
In a deregulated power system, the electric power demand is extending ordinary which may lead to overloads and loss of generation. Transient stability studies put a fundamental part in power systems, which give information related to the capacity of a power structure to stay in synchronism during major disturbances resulting from either the loss of generation or transmission facilities, sudden or sustained changes. The examination of transient quality is discriminating to work the power structure more secure and this paper focuses on growing the transient relentlessness using FACTS devices like Static Synchronous Series Compensator (SSSC) and static synchronous compensator (STATCOM). These FACTS contraptions are in a perfect world set on transmission structure using Sensitivity approach framework.
These slides present the introduction to FACTS devices. Later we will discuss about its modelling and control aspect applications. This comes under the topic on power electronics application in smart and microgrid systems.
UPFC in order to Enhance the Power System ReliabilityIJMER
The maintenance and reliability of the power system has become a major aspect of study. The
solution is the use of FACTS devices especially the use of UPFC. Unified Power Flow Controller (UPFC)
is the most widely used FACTS device to control the power flow and to optimize the system stability in the
transmission line. It is used to control the power flow in the transmission systems by controlling the
impedance, voltage magnitude and phase angle. This controller offers advantages in terms of static and
dynamic operation of the power system. The UPFC with its various modes of operation is understood.
Second, the operation of control system used in its converters is also studied. Finally by help of modeling
of a power system in SIMULINK / MATLAB SIMPOWERSYSTEM and by installing single phase UPFC
in transmission link, its use as power flow controller and voltage injection and constructing a lab scale
model of UPFC is discussed also.
Flexible AC Transmission System (FACTS):
Alternating current transmission systems incorporating power electronic-based and other static controllers to enhance controllability and increase power transfer capability.
FACTS Controller:
What is FACTS? A power electronic-based system and other static equipment that provide control of one or more AC transmission system parameters.
Basic types of FACTS Controllers Based on the connection, generally FACTS controller can be classified as follows: Series controllers
Shunt controllers
Combined series-series controllers
Combined series-shunt controllers
Transformer-Less UPFC for Wind Turbine ApplicationsIJMTST Journal
In this paper, an innovative technique with a new concept of transformer-less unified power flow controller
(UPFC) is implemented. The construction of the conventional UPFC that consists of two back-to-back inverters
which results in complexity and bulkiness which involves the transformers which are complication for
isolation & attaining high power rating with required output waveforms. To reduce a above problem to a
certain extent, a innovative transformer-less UPFC based on less complex configuration with two cascade
multilevel inverters (CMIs) has been proposed. Unified power flow controller (UPFC) has been the most
versatile Flexible AC Transmission System (FACTS) device due to its ability to control real and reactive power
80w on transmission lines while controlling the voltage of the bus to which it is connected. UPFC being a
multi-variable power system controller it is necessary to analyze its effect on power system operation. The
new UPFC offers several merits over the traditional technology, such as Transformer-less, Light weight, High
efficiency, Low cost & Fast dynamic response. This paper mainly highlights the modulation and control for
this innovative transformer-less UPFC, involving desired fundamental frequency modulation (FFM) for low
total harmonic distortion (THD), independent active and reactive power control over the transmission line,
dc-link voltage balance control, etc. The unique capabilities of the UPFC in multiple line compensation are
integrated into a generalized power flow controller that is able to maintain prescribed, and independently
controllable, real power & reactive power flow in the line. UPFC simply controls the magnitude and angular
position of the injected voltage in real time so as to maintain or vary the real and reactive power flow in the
line to satisfy load demand & system operating conditions. UPFC can control various power system
parameters, such as bus voltages and line flows. The impact of UPFC control modes and settings on the
power system reliability has not been addressed sufficiently yet. Cascade multilevel inverters has been
proposed to have an overview of producing the light weight STATCOM’s which enhances the power quality at
the output levels.When the multilevel converter is applied to STATCOM, each of the cascaded H-bridge
converters should be equipped with a galvanically isolated and floating dc capacitor without any power
source or circuit. This enables to eliminate a bulky, heavy, and costly line-frequency transformer from the
cascade STATCOM. When no UPFC is installed, interruption of either three-phase line due to a fault reduces
an active power flow to half, because the line impedance becomes double before the interruption. Installing
the UPFC makes it possible to control an amount of active power flowing through the transmission system.
Results has been shown through MATLAB Simulink
TEACHING AND LEARNING BASED OPTIMISATIONUday Wankar
Teaching–Learning-Based Optimization (TLBO) seems to be a rising star from amongst a number of metaheuristics with relatively competitive performances. It is reported that it outperforms some of the well-known metaheuristics regarding constrained benchmark functions, constrained mechanical design, and continuous non-linear numerical optimization problems. Such a breakthrough has steered us towards investigating the secrets of TLBO’s dominance. This report’s findings on TLBO qualitatively and quantitatively through code-reviews and experiments, respectively.
It is a selection of best element (with regard to some criteria) from some set of available alternatives. In the simplest case, an optimization problem consist of maximizing or minimizing a real function by choosing input values from within an allowed set and computing the value of function. The classical optimization techniques are useful in finding the optimum solution or unconstrained maxima or minima of continuous and differentiable functions. These are analytical methods and make use of differential calculus in locating the optimum solution. The classical methods have limited scope in practical applications as some of them involve objective functions which are not continuous and un-differentiable. Yet, the study of these classical techniques of optimization form a basis for developing most of the numerical techniques that have evolved into advanced techniques more suitable to today’s practical problems.
The difficulties associated with using mathematical optimization on large-scale engineering problems have contributed to the development of alternative solutions. Linear programming and dynamic programming techniques, for example, often fail (or reach local optimum) in solving NP-hard problems with large number of variables and non-linear objective functions. To overcome these problems, researchers have proposed evolutionary-based algorithms for searching near-optimum solutions to problems.
Evolutionary algorithms (EAs) are stochastic search methods that mimic the metaphor of natural biological evolution and/or the social behaviour of species. Examples include how ants find the shortest route to a source of food and how birds find their destination during migration. The behaviour of such species is guided by learning, adaptation, and evolution. To mimic the efficient behaviour of these species, various researchers have developed computational systems that seek fast and robust solutions to complex optimization problems. The first evolutionary-based technique introduced in the literature was the genetic algorithms (Gas). GAs were developed based on the Darwinian principle of the ‘survival of the fittest’ and the natural process of evolution through reproduction. Based on its demonstrated ability to reach near-optimum solutions to large problems, the GAs technique has been used in many applicationsin science and engineering. Despite their benefits, GAs may require long processing time for a near optimum solution to evolve. Also, not all problems lend themselves well to a solution with GAs.
For three decades, many mathematical programming methods have been developed to solve optimization problems. However, until now, there has not been a single totally efficient and robust method to coverall optimization problems that arise in the different engineering fields.Most engineering application design problems involve the choice of design variable values that better describe the behaviour of a system.At the same time, those results should cover the requirements and specifications imposed by the norms for that system. This last condition leads to predicting what the entrance parameter values should be whose design results comply with the norms and also present good performance, which describes the inverse problem.Generally, in design problems the variables are discreet from the mathematical point of view. However, most mathematical optimization applications are focused and developed for continuous variables. Presently, there are many research articles about optimization methods; the typical ones are based on calculus,numerical methods, and random methods.
The calculus-based methods have been intensely studied and are subdivided in two main classes: 1) the direct search methods find a local maximum moving a function over the relative local gradient directions and 2) the indirect methods usually find the local ends solving a set of non-linear equations, resultant of equating the gradient from the object function to zero, i.e., by means of multidimensional generalization of the notion of the function’s extreme points from elementary calculus given smooth function without restrictions to find a possible maximum which is to be restricted to those points whose slope is zero in all directions. The real world has many discontinuities and noisy spaces, which is why it is not surprising that the methods depending upon the restrictive requirements of continuity and existence of a derivative, are unsuitable for all, but a very limited problem domain. A number of schemes have been applied in many forms and sizes. The idea is quite direct inside a finite search space or a discrete infinite search space, where the algorithms can locate the object function values in each space point one at a time. The simplicity of this kind of algorithm is very attractive when the numbers of possibilities are very small. Nevertheless, these outlines are often inefficient, since they do not complete the requirements of robustness in big or highly-dimensional spaces, making it quite a hard task to find the optimal values. Given the shortcomings of the calculus-based techniques and the numerical ones the random methods have increased their popularity.
Finding an alternative with the most cost effective or highest achievable performance under the given constraints, by maximizing desired factors and minimizing undesired ones. It also mean that it make best use of a situation or resource. In comparison, maximization means trying to attain the highest or maximum result or outcome without regard to cost or expense. Practice of optimization is restricted by the lack of full information, and the lack of time to evaluate what information is available (see bounded reality for details). In computer simulation (modeling) of business problems, optimization is achieved usually by using linear programming techniques of operations research.
The first ant colony optimization (ACO) called ant system was inspired through studying of the behaviour of ants in 1991 by Macro Dorigo and co-workers. An ant colony is highly organized, in which one interacting with others through pheromone in perfect harmony. Optimization problems can be solved through simulating ant’s behaviours. Since the first ant system algorithm was proposed, there is a lot of development in ACO. In ant colony system algorithm, local pheromone is used for ants to search optimum result. However, high magnitude of computing is its deficiency and sometimes it is inefficient. Thomas Stützle etal. Introduced MAX-MIN Ant System (MMAS) in 2000. It is one of the best algorithms of ACO. It limits total pheromone in every trip or sub-union to avoid local convergence. However, the limitation of pheromone slows down convergence rate in MMAS.
The gas turbine is an internal combustion engine that uses air as the working fluid. The engine extracts chemical energy from fuel and converts it to mechanical energy using the gaseous energy of the working fluid (air) to drive the engine and propeller, which, in turn, propel the aeroplane.
The gas turbine is an internal combustion engine that uses air as the working fluid. The engine extracts chemical energy from fuel and converts it to mechanical energy using the gaseous energy of the working fluid (air) to drive the engine and propeller, which, in turn, propel the airplane.
This ppt show the steps to rewind the Brushless motor(BLDC)
If you fly brushless you've probably cooked a motor or two. You also probably know there are many different types of motors. Similar motors when wound differently performs very differently. Whether you've burned the motor up, or just want to alter performance, rewinding is a cheap solution for a patient modeller.
For this tutorial, I will be using Dynam E-Razor 450 Brushless Motor 60P-DYM-0011 (2750Kv). It is a Delta wound 8T (It means 8 turns ) quad wind.
The winding pattern described in this tutorial (called an ABC wind - ABCABCABC as you go around the stator) works for any brushless motor with 9 stator teeth and 6 magnets.
This ppt show the steps to rewind the Brushless motor(BLDC)
If you fly brushless you've probably cooked a motor or two. You also probably know there are many different types of motors. Similar motors when wound differently performs very differently. Whether you've burned the motor up, or just want to alter performance, rewinding is a cheap solution for a patient modeller.
For this tutorial, I will be using Dynam E-Razor 450 Brushless Motor 60P-DYM-0011 (2750Kv). It is a Delta wound 8T (It means 8 turns ) quad wind.
The winding pattern described in this tutorial (called an ABC wind - ABCABCABC as you go around the stator) works for any brushless motor with 9 stator teeth and 6 magnets.
Our project is a persistence of vision display (POV) that spins 360 degrees horizontally. The purpose of our POV display project is to create a small apparatus that will create a visual using only a small number of LEDs as it spins in a circle. When the LEDs rotate several times around a point in less than a second, the human eye reaches its limit of motion perception and creates an illusion of a continuous image. Therefore, our POV display demonstrates this phenomenon by creating a visual as the LEDs spin rapidly in a circle and the person watching will see one continuous image.
Arm cortex (lpc 2148) based motor speedUday Wankar
The project is designed to control the speed of a DC and AC motor using an
ARM7 LPC2148 processor. The speed of motor is directly proportional to the voltage
applied across its terminals. Hence, if voltage across motor terminal is varied, then
speed can also be varied. This project uses the above principle to control the speed of
the motor by varying the duty cycle of the pulses applied to it, popularly known as
PWM control. The project uses input button interfaced to the processor, which are
used to control the speed of motor. Pulse Width Modulation is generated at the output
by the microcontroller as per the program. The program is written in Embedded C.
The average voltage given or the average current flowing through the motor
will change depending on the duty cycle, ON and OFF time of the pulses, so the speed
of the motor will change. A motor driver IC is interfaced to the ARM7 LPC2148
processor board for receiving PWM signals and delivering desired output for speed
control. Further the project can be enhanced by using power electronic devices such
as IGBTs to achieve speed control higher capacity industrial motors.
Arm Processor Based Speed Control Of BLDC MotorUday Wankar
The project is designed to control the speed of a DC motor using an ARM series processor. The speed of DC motor is directly proportional to the voltage applied across its terminals. Hence, if voltage across motor terminal is varied, then speed can also be varied. This project uses the above principle to control the speed of the motor by varying the duty cycle of the pulse applied to it (popularly known as PWM control). The project uses input button interfaced to the processor, which are used to control the speed of motor. PWM (Pulse Width Modulation) is generated at the output by the microcontroller as per the program. The program is written in Embedded C. The average voltage given or the average current flowing through the motor will change depending on the duty cycle (ON and OFF time of the pulses), so the speed of the motor will change. A motor driver IC is interfaced to the STM32 board for receiving PWM signals and delivering desired output for speed control of a small DC motor. Further the project can be enhanced by using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.
Arm cortex ( lpc 2148 ) based motor speed control Uday Wankar
The project is designed to control the speed of a DC and AC motor using an ARM7 LPC2148 processor. The speed of motor is directly proportional to the voltage applied across its terminals. Hence, if voltage across motor terminal is varied, then speed can also be varied. This project uses the above principle to control the speed of the motor by varying the duty cycle of the pulses applied to it, popularly known as PWM control. The project uses input button interfaced to the processor, which are used to control the speed of motor. Pulse Width Modulation is generated at the output by the microcontroller as per the program. The program is written in Embedded C.
The average voltage given or the average current flowing through the motor will change depending on the duty cycle, ON and OFF time of the pulses, so the speed of the motor will change. A motor driver IC is interfaced to the ARM7 LPC2148 processor board for receiving PWM signals and delivering desired output for speed control. Further the project can be enhanced by using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.
Power Quality is a combination of Voltage profile, Frequency profile, Harmonics contain and reliability of power supply.
The Power Quality is defined as the degree to which the power supply approaches the ideal case of stable, uninterrupted, zero distortion and disturbance free supply.
MSEB was set up in 1960 to generate, transmit and distribute power to all consumers in
Maharashtra excluding Mumbai. MSEB was the largest SEB in the country. The generation
capacity of MSEB has grown from 760 MW in 1960-61 to 9771 MW in 2001-02. The customer
base has grown from 1,07,833 in 1960-61 to 1,40,09,089 in 2001-02.
C.S.T.P.S in contribution much in field of production of electricity. It is not only number
one thermal power station in Asia but also has occupied specific position on the international
map.
The first set was commission on August 1983 & was dedicated to nation by then PM
(late) Mrs. Indira Gandhi & second set commission on July 1984. The third & fourth units of
CSTPS under stage 2 were commissioned on the 3rd May 1985 & 8th March 1986 respectively.
The units 5 & 6 were commissioned on the 22nd March 1991 & 11th March 1992 respectively one
more units of 500MW was added to the CSTPS on making its generation to 2340 MW &
making “C.S.T.P.S.” as the giant in Power Generation of CSTPS.
With the development of industry and
agriculture, a great amount of energy such as coal, oil
and gas has been consumed in the world. Extensive
use of these fossil energies deteriorates a series of
problems like energy crisis, environmental pollution
and so on. Everybody knows that the fossil energy
reserves are finite, some day it will be exhausted.
It is possible that the world will face a
global energy crisis due to a decline in the
availability of cheap oil and recommendations to a
decreasing dependency on fossil fuel. This has led to
increasing interest in alternate power/fuel research
such as fuel cell technology, hydrogen fuel, biodiesel,
Karrick process, solar energy, geothermal energy,
tidal energy and wind. Today, solar energy and wind
energy have significantly alternated fossil fuel with
big ecological problems.
With the development of the science and
technology, power generation using solar energy and
wind power is gradually known by more and more
people. And it is widespread used in many developed
countries. The merits of the solar and wind power
generation are very obvious-infinite and nonpolluting.
The raw materials of the solar and wind
power generation derived from nature, and wind
power generation can work twenty-four hours a day,
solar power generation only works by daylight. In
addition, this kind of power generation has no
exhaust emission and there is no influence to the
nature. But it also has some shortcomings. Because
of the imperfect of the technology, equipment of the
solar and wind power generation is very expensive.
By far, it cannot be widely used.
In addition, solar and wind power
generation system affected by the changing of the
weather very much, so it has obvious defects in
reliability compared with fossil fuel, and it is difficult
to make it fit for practical use the lack of economical
efficiency .Because of these problems it needs to
increase the reliability of energy supply by
developing a system which interacts Solar and wind
energy. This kind of system is usually called windsolar
hybrid power generation system significantly
Hybrid power generation by and solar –windUday Wankar
With the development of industry and
agriculture, a great amount of energy such as coal, oil
and gas has been consumed in the world. Extensive
use of these fossil energies deteriorates a series of
problems like energy crisis, environmental pollution
and so on. Everybody knows that the fossil energy
reserves are finite, some day it will be exhausted.
It is possible that the world will face a
global energy crisis due to a decline in the
availability of cheap oil and recommendations to a
decreasing dependency on fossil fuel. This has led to
increasing interest in alternate power/fuel research
such as fuel cell technology, hydrogen fuel, biodiesel,
Karrick process, solar energy, geothermal energy,
tidal energy and wind. Today, solar energy and wind
energy have significantly alternated fossil fuel with
big ecological problems.
With the development of the science and
technology, power generation using solar energy and
wind power is gradually known by more and more
people. And it is widespread used in many developed
countries. The merits of the solar and wind power
generation are very obvious-infinite and nonpolluting.
The raw materials of the solar and wind
power generation derived from nature, and wind
power generation can work twenty-four hours a day,
solar power generation only works by daylight. In
addition, this kind of power generation has no
exhaust emission and there is no influence to the
nature. But it also has some shortcomings. Because
of the imperfect of the technology, equipment of the
solar and wind power generation is very expensive.
By far, it cannot be widely used.
In addition, solar and wind power
generation system affected by the changing of the
weather very much, so it has obvious defects in
reliability compared with fossil fuel, and it is difficult
to make it fit for practical use the lack of economical
efficiency .Because of these problems it needs to
increase the reliability of energy supply by
developing a system which interacts Solar and wind
energy. This kind of system is usually called windsolar
hybrid power generation system significantly
This paper presents Grid Solver Bot which is a self-driven vehicle capable of localizing itself in a grid and planning a path between two nodes. It can avoid particular nodes and plan path between two allowed nodes. Breadth-first search & Dijkstra's Algorithm have been used for finding the path between two allowed nodes. The searching of a block over grid is easier when the rows and columns i.e. m* n of a grid is fixed. But when the grid is dynamic or changes over time than in such situation we require a generalized algorithm for traversing over a grid. In these paper we develop an approach for searching an object and also able to avoid an obstacle which was placed in a junction (meeting point of row and column). Here, we use different algorithms like Dijkistra’s, Best first search and A star algorithms. We develop an approach to find the block with minimum shortest path with the help of priority based algorithm. The vehicle is also capable of transferring blocks from one node to another. In fact, this vehicle is a prototype of a self-driven vehicle capable of transporting passengers and it can also be used in industries to transfer different items from one place to another.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
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Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
2. INDEX
SR.NO. CHAPTER NAME PAGE
NO.
1 1.INTRODUCTION 1
2 2.TYPES OF FACTS CONTROLLERS 3
2.1series Controller
2.2 Shunt Controllers
2.3 Combined Series –Series Controllers
2.4 Combined Series-Shunt Controllers
2.5 Benefits Of Facts Controllers
3 3. CONTROL OF POWER SYSTEM 11
4
5
6
3.1 Generation ,Transmission ,Distribution
3.2 Power System Constraints
3.3 Controllability Of Power System
3.4 Benefits Of Control Of Power System
3.5 Benefits Of Utilising Facts Devices
3.6 Classification
3.6.1 First Generation Of Facts
3.6.11 Static Var Compensator
3.6.12 Thyristor Controlled Series Capacitor
3.6.2 Secind Generation Facts
3.6.21static Compensation
3.6.22 Static Synchronous Series Compensator
3.6.23 Unified Power Flow Controller
APPLICATIONS
4.1facts Application To Steady State Power System Problems
4.2facts Application To Optimal Power Flow
CONCLUSION
REFERENCES
19
20
21
3. LIST OF FIGURES
Sr.No. Fig. No. Name Of Figure Page No.
1 Fig.2.1 Single line diagram of series compensator 3
2 Fig.2.2 Diagram of parallel compensator 4
3 Fig .3.1 Block diagram of power system 11
4 Fig. 3.2 Single line diagram and phasordiagram 13
5 Fig.3.3 Unified power flow controller 17
4. CHAPTER 1: INTRODUCTION
The electricity supply industry is undergoing a profound transformation worldwide.
Market forces, scarcer natural resources, and an ever-increasing demand for electricity are some
of the drivers responsible for such unprecedented change. Against this background of rapid
evolution, the expansion programs of many utilities are being thwarted by a variety of well-
founded, environment, land-use, and regulatory pressures that prevent the licensing and building
of new transmission lines and electricity generating plants.
The ability of the transmission system to transmit power becomes impaired by one or
more of the following steady state and dynamic limitations: (a) angular stability, (b) voltage
magnitude, (c) thermal limits, (d) transient stability, and (e) dynamic stability. These limits
define the maximum electrical power to be transmitted without causing damage to transmission
lines and electrical equipment .In principle, limitations on power transfer can always be relieved
by the addition of new transmission lines and generation facilities. Alternatively, flexible
alternating current transmission system (FACTS) controllers can enable the same objectives to
be met with no major alterations to power system layout. FACTS are alternating current
transmission systems incorporating power electronic-based and other static controllers to
enhance controllability and increase power transfer capability
.
The FACTS concept is based on the substantial incorporation of power electronic
devices and methods into the high-voltage side of the network, to make it electronically
controllable. FACTS controllers aim at increasing the control of power flows in the high-
voltage side of the network during both steady state and transient conditions. The concept
of FACTS as a total network control philosophy was introduced in 1988 by Dr. N.
Hingorani .Owing to many economical and technical benefits it promised, FACTS received
the support of electrical equipment manufacturers, utilities, and research organizations
around the world. This interest has led to significant technological developments of
FACTS controllers. Several kinds of FACTS controllers have been commissioned in
various parts of the world. The most popular are: load tap changers, phase-angle regulators,
5. static VAR compensators, thyristor controlled series compensators, interphase power
controllers, static compensators, and unified power flow controllers.
In this paper, the state of the art in the development of FACTS controllers is
presented. The paper presents the objectives, the types, and the benefits of FACTS
controllers. Moreover, various FACTS controllers are described, their control attributes are
presented, and their role in power system operation is analyzed.
Objectives of FACTS controllers
The main objectives of FACTS controllers are the following:
1. Regulation of power flows in prescribed transmission routes.
2. Secure loading of transmission lines nearer to their thermal limits.
3. Prevention of cascading outages by contributing to emergency control.
4. Damping of oscillations that can threaten security or limit the usable line capacity.
6. CHAPTER 2: TYPES OF FACTS CONTROLLERS
2.1 Series controllers
The series controller could be a variable impedance, such as capacitor,
reactor, or a power electronics based variable source of main frequency, sub-synchronous
and harmonic frequencies (or a combination) to serve the desired load. In principle, all
series controllers inject voltage in series with the line. As long as the voltage is in phase
quadrature with the line current, the series controller only supplies or consumes variable
reactive power. Any other phase relationship will involve handling of real power as well.
Series controllers include SSSC, IPFC, TCSC, TSSC, TCSR, and TSSR.
Fig2.1: Single line diagram of series compensator.
2.2 Shunt controllers.
As in the case of series controllers, the shunt controllers may be variable
impedance, variable source, or a combination of these. In principle, all shunt controllers
inject current into the system at the point of connection. Even a variable shunt impedance
connected to the line voltage causes a variable current flow and hence represents injection
7. Even a variable shunt impedance connected to the line voltage causes a variable current
flow and hence represents injection of current into the line. As long as the injected current
is in phase quadrature with the line voltage, the shunt controller only supplies or consumes
reactive power. Any other phase relationship will involve handling of real power as well.
.
Fig2.2: Diagram of parallel compensator
2.3 Combined series-series controllers:-
This could be a combination of separate series controllers, which are
controlled in a coordinated manner, in a multiline transmission system. Or it could be a
unified controller in which series controllers provide independent series reactive
compensation for each line but also transfer real power among the lines via the proper link.
The real power transfer capability of the unified series-series controller, referred to as
IPFC, makes it possible to balance both real and reactive power flow in the lines and
thereby maximize the utilization of the
8. transmission system. The term “unified” here means that the dc terminals of all controller
converters are all connected together for real power transfer.
2.4 Combined series-shunt controllers:-
This could be a combination of separate shunt and series
controllers, which are controlled in a coordinated manner, or a UPFC with series and shunt
elements. In principle, combined shunt and series controllers inject current into the system
with the shunt part of the controller and voltage in series in the line with the series part of
the controller. However, when the shunt and series controllers are unified, there can be a
real power exchange between the series and shunt controllers via the proper link.
Combined series-shunt controllers include UPFC, TCPST, and TCPA
FACTS CONTROLLERS
STATCOM:
STATCOM is a static synchronous generator operated as a shunt-
connected static var compensator whose capacitive or inductive output current can
be controlled independent of the ac system voltage. The use of STATCOM as a
FACTS controller is proposed .
SVC:
SVC is a shunt-connected static var generator or absorber whose output is
adjusted to exchange capacitive or inductive current so as to maintain or control
specific parameters of the electrical power system (typically bus voltage). SVC is
an important FACTS controller already widely in operation. Ratings range from
60 to 600 MVAR , SVC can be considered as a “first generation” FACTS
controller and uses thyristor controllers. It is a shunt reactive compensation
controller consisting of a combination of fixed capacitor or thyristor-switched
capacitor in conjunction with thyristor-controlled reactor.
9. TCR:
TCR is a shunt-connected thyristor-controlled inductor whose effective
reactance is varied in a continuous manner by partial-conduction control of the
thyristor valve. TCR has been used as one of the economical alternatives of
FACTS controllers .
TSC:
TSC is a shunt-connected thyristor-switched capacitor whose effective
reactance is varied in a stepwise manner by full- or zero-conduction operation of
the thyristor valve .
TSR:
TSR is a shunt-connected thyristor-switched inductor whose effective
reactance is varied in a stepwise manner by full- or zero-conduction operation of
the thyristor valve .
TCBR:
TCBR is a shunt-connected thyristor-switched resistor, which is controlled to
aid stabilization of a power system or to minimize power acceleration of a
generating unit during a disturbance
.
SSSC:
SSSC is a static synchronous generator operated without an external electric
energy source as a series compensator whose output voltage is in quadrature with,
and controllable independently of, the line current for the purpose of increasing or
decreasing the overall reactive voltage drop across the line and thereby
controlling the transmitted electric power . The SSSC may include transiently
rated energy storage or energy absorbing devices to enhance the dynamic
behavior of the power system by additional temporary real power compensation,
to increase or decrease momentarily, the overall real (resistive) voltage drop
across the line.
10. TCSC:
TCSC is a capacitive reactance compensator, which consists of a series
capacitor bank shunted by a thyristor-controlled reactor in order to provide a
smoothly variable series capacitive reactance. The description of the first TCSC
installation is given .
TSSC:
TSSC is a capacitive reactance compensator, which consists of a series
capacitor bank shunted by a thyristor-switched reactor to provide a stepwise
control of series capacitive reactance.
TCSR:
TCSR is an inductive reactance compensator, which consists of a series
reactor shunted by a thyristor-controlled reactor to provide a smoothly variable
series inductive reactance .
TSSR:
TSSR is an inductive reactance compensator, which consists of a series
reactor shunted by a thyristor-controlled reactor to provide a stepwise control of
series inductive reactance .
TCPST:
TCPST is a phase-shifting transformer adjusted by thyristor switches to
provide rapidly variable phase angle . This controller is also referred to as
TCPAR.
UPFC:
UPFC is a combination of STATCOM and a SSSC which are coupled via a
common dc link to allow bidirectional flow of real power between the series
output terminals of the SSSC and the shunt output terminals of the STATCOM
11. and are controlled to provide concurrent real and reactive series line
compensation without an external electric energy source. The UPFC, by means of
angularly unconstrained series voltage injection, is able to control, concurrently or
selectively, the transmission line voltage, impedance, and angle or, alternatively,
the real and reactive power flow in the line. The UPFC may also provide
independently controllable shunt reactive compensation. The UPFC proposed by
Gyugyi is the most versatile FACTS controller for the regulation of voltage and
power flow in a transmission line.
GUPFC:
GUPFC can effectively control the power system parameters such as bus
voltage, and real and reactive power flows in the lines . A simple scheme of
GUPFC consists of three converters, one connected in shunt and two connected in
series with two transmission lines terminating at a common bus in a substation. It
can control five quantities, i.e., a bus voltage and independent active and reactive
power flows in the two lines. The real power is exchanged among shunt and series
converters via a common dc link.
IPC:
IPC is a series-connected controller of active and reactive power consisting, in
each phase, of inductive and capacitive branches subjected to separately phase-
shifted voltages. The active and reactive power can be set independently by
adjusting the phase shifts and/or the branch impedances, using mechanical or
electronic switches. In the particular case where the inductive and capacitive
impedance form a conjugate pair, each terminal of the IPC is a passive current
source dependent on the voltage at the other terminal and the practical design
aspects of a 200 MW prototype for the interconnection of the 120 kV networks
were described. However, the original concept proposed has undergone
modifications that are described
.
12. TCVL:
TCVL is a thyristor-switched metal-oxide varistor used to limit the voltage
across its terminals during transient conditions .
TCVR:
TCVR is a thyristor-controlled transformer that can provide variable in-
phase voltage with continuous control.
IPFC:
IPFC is a combination of two or more SSSCs that are coupled via a common
dc link to facilitate bi-directional flow of real power between the ac terminals of
the SSSCs and are controlled to provide independent reactive compensation for
the adjustment of real power flow in each line and maintain the desired
distribution of reactive power flow among the lines. The IPFC structure may also
include a STATCOM, coupled to the IPFC common dc link, to provide shunt
reactive compensation and supply or absorb the overall real power deficit of the
combined SSSCs.
2.5 Benefits Of Facts Controllers:
FACTS controllers enable the transmission owners to obtain, on a case-by-
case basis, one or more of the following benefits:
2.5.1Cost:
Due to high capital cost of transmission plant, cost considerations
frequently Over weigh all other considerations. Compared to alternative methods
of solving transmission loading problems, FACTS technology is often the most
economic alternative.
2.5.2 Convenience:
All FACTS controllers can be retrofitted to existing ac transmission plant with
13. varying degrees of ease. Compared to high voltage direct current or six-phase
transmission schemes, solutions can be provided without wide scale system
disruption and within a reasonable timescale.
2.5.3 .Environmental impact:
In order to provide new transmission routes to supply an ever increasing
worldwide demand for electrical power, it is necessary to acquire the right to
convey electrical energy over a given route. It is common for environmental
opposition to frustrate attempts to establish new transmission routes. FACTS
technology, however, allows greater throughput over existing routes, thus meeting
consumer demand without the construction of new transmission lines. However,
the environmental impact of the FACTS device itself may be considerable.
2.5.4. Control of power flow to follow a contract, meet the utilities own needs,
ensure optimum power flow, minimize the emergency conditions, or a
combination thereof.
2.5.5. Contribute to optimal system operation by reducing power losses and
improving voltage profile.
2.5.6. Increase the loading capability of the lines to their thermal capabilities,
including short term and seasonal.
2.5.7 Increase the system security by raising the transient stability limit, limiting
short-circuit currents and overloads, managing cascading blackouts and damping
electromechanical oscillations of power systems and machines.
2.5.8. Provide secure tie line connections to neighboring utilities and regions
thereby decreasing overall generation reserve requirements on both sides.
14. CHAPTER 3: CONTROL OF POWER SYSTEMS
3.1 Generation, Transmission, Distribution
In any power system, the creation, transmission, and utilization of
electrical power can be separated into three areas, which traditionally determined
the way in which electric utility companies had been organized. These are
illustrated in Figure 1 and are:
• Generation
• Transmission
• Distribution
Fig 3.1 : Block Diagram of power system
Although power electronic based equipment is prevalent in each of these three
areas, such as with static excitation systems for generators and Custom Power
equipment in distribution systems, the focus of this paper and accompanying
presentation is on transmission, i.e. moving the power from where it is generated
to where it is utilized.
3.2 Power SystemConstraints
As noted in the introduction, transmission systems are being pushed closer
to their stability and thermal limits while the focus on the quality of power
delivered is greater than ever. The limitations of the transmission system can take
many forms and may involve power transfer between areas or within a single area
or region and may include one or more of the following characteristics:
• Steady-State Power Transfer Limit
15. CHAPTER 4:APPLICATIONS
4.1 Facts Applications To Steady State Power System Problems
For the sake of completeness of this review, a brief overview of the
FACTS devices applications to different steady state power system problems is presented
in this section. Specifically, applications of FACTS in optimal power flow and deregulated
electricity market will be reviewed.
4.2 FACTS Applications to Optimal Power Flow
In the last two decades, researchers developed new algorithms for solving the
optimal power flow problem incorporating various FACTS devices . Generally in power
flow studies, the thyristor controlled FACTS devices, such as SVC and TCSC, are usually
modeled as controllable impedance controllable sources. The Interline Power Flow
Controller (IPFC) is one of the voltage source converter(VSC) based FACTS Controllers
which can effectively manage the power flow via multi-line Transmission System.
•Better utilization of existing transmission system assets
•Increased transmission system reliability and availability
•Increased dynamic and transient grid stability and reduction of loop
flows
•Increased quality of supply for sensitive industries
• Voltage Stability Limit
• Dynamic Voltage Limit
• Transient Stability Limit
• Power System Oscillation Damping Limit
• Inadvertent Loop Flow Limit
• Thermal Limit
• Short-Circuit Current Limit
• Others
16. Each transmission bottleneck or regional constraint may have one or more of
these system-level problems. The key to solving these problems in the most cost-
effective and coordinated manner is by thorough systems engineering analysis.
3.3 Controllability of Power Systems
To illustrate that the power system only has certain variables that can be
impacted by control, we have considered here the power-angle curve, shown in
Figure 2. Although this is a steady-state curve and the implementation of FACTS
is primarily for dynamic issues, this illustration demonstrates the point that there
are primarily three main variables that can be directly controlled in the power
system to impact its performance. These are:
• Voltage
• Angle
• Impedance
Fig 3.2: Single line diagram with phasor diagram
3.4 Benefits of Control of Power Systems
Once power system constraints are identified and through system
studies viable solutions options are identified, the benefits of the added power
system control must be determined. The following offers a list of such benefits:
• Increased Loading and More Effective Use of Transmission Corridors
17. • Added Power Flow Control
• Improved Power System Stability
• Increased System Security
• Increased System Reliability
• Added Flexibility in Starting New Generation
• Elimination or Deferral of the Need for New Transmission Lines
3.5 Benefits of utilizing FACTS devices
The benefits of utilizing FACTS devices in electrical transmission systems can be
summarized as follows
•Better utilization of existing transmission system assets
•Increased transmission system reliability and availability
•Increased dynamic and transient grid stability and reduction of loop flows
•Increased quality of supply for sensitive industries
3.6 Classification
There are different classifications for the FACTS devices: Depending on the
type of connection to the network FACTS devices can differentiate four
categories
• serial controllers
• derivation controllers
• serial to serial controllers
• serial-derivation controllers
Depending on technological features, the FACTS devices can be divided into two
generations
• first generation: used thyristors with ignition controlled by gate(SCR).
. second generation: semiconductors with ignition and extinction
controlled by gate (GTO´s , MCTS , IGBTS , IGCTS , etc).
18. 3. 6.1 First Generation Of Facts
3.6.2 Static VAR Compensator (SVC)
A static VAR compensator (or SVC) is an electrical device for providing fast-
acting reactive power on high-voltage electricity transmission networks. SVCs are
part of the Flexible AC transmission system device family, regulating voltage and
stabilizing the system. The term "static" refers to the fact that the SVC has no
moving parts (other than circuit breakers and disconnects, which do not move
under normal SVC operation). Prior to the invention of the SVC, power factor
compensation was the preserve of large rotating machines such as synchronous
condensers. The SVC is an automated impedance matching device, designed to
bring the system closer to unity power factor
3. 6.3 .Thyristor-Controlled Series Capacitor (TCSC)
TCSC controllers use thyristor-controlled reactor (TCR) in parallel with
capacitor segments of series capacitor bank. The combination of TCR and
capacitor allow the capacitive reactance to be smoothly controlled over a wide
range and switched upon command to a condition where the bi-directional
thyristor pairs conduct continuously and insert an inductive reactance into the
line. TCSC is an effective and economical means of solving problems of transient
stability, dynamic stability, steady state stability and voltage stability in long
transmission lines. TCSC, the first generation of FACTS, can control the line
impedance through the introduction of a thyristor controlled capacitor in series
with the transmission line
3.6.4 Thyristor-Controlled Phase Shifter (TCPS)
In a TCPS control technique the phase shift angle is determined as a nonlinear
function of rotor angle and speed. However, in real-life power system with a large
number of generators, the rotor angle of a single generator measured with respect
to the system reference will not be very meaningful.
3.6.5 SECOND GENERATION OF FACTS
3.6. 6 Static Compensator (STATCOM)
19. The emergence of FACTS devices and in particular GTO thyristor-based
STATCOM has enabled such technology to be proposed as serious competitive
alternatives to conventional SVC [21] A static synchronous compensator
(STATCOM) is a regulating device used on alternating current electricity
transmission networks. It is based on a power electronics voltage-source converter
and can act as either a source or sink of reactive AC power to an electricity
network. If connected to a source of power it can also provide active AC power. It
is a member of the FACTS family of devices. Usually a STATCOM is installed to
support electricity networks that have a poor power factor and often poor voltage
regulation. There are however, other uses, the most common use is for voltage
stability.
3.6.7 Static Synchronous Series Compensator (SSSC)
This device work the same way as the STATCOM. It has a voltage source
converter serially connected to a transmission line through a transformer. It is
necessary an energy source to provide a continuous voltage through a condenser
and to compensate the losses of the VSC. A SSSC is able to exchange active and
reactive power with the transmission system. But if our only aim is to balance the
reactive power, the energy source could be quite small. The injected voltage can
be controlled in phase and magnitude if we have an energy source that is big
enough for the purpose. With reactive power compensation only the voltage is
controllable, because the voltage vector forms 90º degrees with the line intensity.
In this case the serial injected voltage can delay or advanced the line current. This
means that the SSSC can be uniformly controlled in any value, in the VSC
working slot.
3.6.8 Unified Power Flow Controller (UPFC)
A unified power flow controller (UPFC) is the most promising device in the
FACTS concept. It has the ability to adjust the three control parameters, i.e. the
bus voltage, transmission line reactance, and phase angle between two buses,
either simultaneously or independently. A UPFC performs this through the
20. control of the in-phase voltage, quadrature voltage, and shunt compensation. The
UPFC is the most versatile and complex power electronic equipment that has
emerged for the control and optimization of power flow in electrical power
transmission systems. It offers major potential advantages for the static and
dynamic operation of transmission lines. The UPFC was devised for the real-time
control and dynamic compensation of ac transmission systems, providing
multifunctional flexibility required to solve many of the problems facing the
power industry. Within the framework of traditional power transmission concepts,
the UPFC is able to control, simultaneously or selectively, all the parameters
affecting power flow in the transmission line. Alternatively, it can independently
control both the real and reactive power flow in the line unlike all other
controllers.
Fig 3.3: Unified power flow controller
21. CONCLUSION
This paper has presented various FACTS controllers and analyzed their control attributes
and benefits. The flexible ac transmission system (FACTS), a new technology based on
power electronics, offers an opportunity to enhance controllability, stability, and power
transfer capability of ac transmission systems. The application of FACTS controllers
throws up new challenges for power engineers, not only in hardware implementation, but
also in design of robust control systems, planning and analysis.
22. REFERENCES
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2) P. W. Sauer and M. A. Pai, Power System Dynamics and Stability. Prentice Hall
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3) J. R. Smith, G. Andersson, and C. W. Taylor, “Annotated Bibliography on Power
System Stability Controls: 1986- 1994”, IEEE Trans. on PWRS, 11(2)(1996), pp. 794
4) N. G. Hingorani and L. Gyugyi, Understanding FACTS: Concepts and Technology of
Flexible AC Transmission Systems. New York: IEEE Press, 2000.
5) N. G. Hingorani, “FACTS-Flexible AC Transmission System”, Proceedings of 5th
International Conference on AC and DC Power Transmission-IEE Conference
Publication 345, 1991, pp. 1–7.
6) N. G. Hingorani, “Flexible AC Transmission”, IEEE Spectrum, April 1993, pp. 40–
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7) N. G. Hingorani, “High Power Electronics and Flexible AC Transmission System”,
IEEE Power Engineering Review, July 1988
8) R. M. Mathur and R. S. Basati, Thyristor-Based FACTS Controllers for Electrical
Transmission Systems. IEEE Press Series in Power Engineering, 2002.
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London, UK: IEE Press, 1999.