1) The document describes a new FACTS device called the Gate Controlled Series Capacitor (GCSC) for controlling power flow in transmission lines.
2) The GCSC uses semiconductor switches connected in parallel with a capacitor to continuously vary the equivalent series reactance. This allows control of power flow without the limitations of existing thyristor controlled series compensation devices.
3) Simulations show the GCSC's ability to control power flow and damp power oscillations in transmission systems, demonstrating its effectiveness as an alternative to other series compensation technologies like the thyristor controlled series capacitor (TCSC).
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Implementation Of Thyristor Controlled Series Capacitor (TCSC) In Transmissio...IJERA Editor
A grid of transmission lines operating at high or extra high voltages is required to transmit power from
generating stations to load. In addition to transmission lines that carry power from source to load, modern power
systems are highly interconnected for economic reasons. The large interconnected transmission networks are
prone to faults due to the lightning discharges and reduce insulation strength. Changing of loads and atmosphere
conditions are unpredictable factors. This may cause overloading of lines due to which voltage collapse takes
place. These problems can be eased by providing sufficient margin of working parameters and power transfer,
but it is not possible due to expansion of transmission network. Still the required margin is reduced by
introduction of fast dynamic control over reactive and active power by high power electronic controllers. This
paper describes about implementation of Thyristor Controlled Series Capacitor (TCSC) in transmission line
model in order to enhance power flow at the receiving end. The triggering pulses to the thyristor are given using
Arduino.
A High Performance PWM Voltage Source Inverter Used for VAR Compensation and ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
The DC-fault Blocking Capability by a New Hybrid Multilevel Converter in HVDC...Editor IJCATR
This paper explains the working principles, supported by simulation results, of a new converter topology in-tended for HVDC
application, called the Alternate Arm Con-verter (AAC). Modular Multilevel Converters deliver small footprints and efficiencies above
99% in their half-bridge format, but only deliver DC-fault blocking with full-bridge sub-modules, and with an unacceptable penalty in
efficiency. The Alternate Arm Converter (AAC) is a hybrid circuit topology using a mixture of full-bridge sub-modules and director
switches which is capable of current control through DC faults while maintaining good efficiency in normal operation. It is hybrid
between the modular multi-level converter, because of the presence of H-bridge cells, and the 2-level converter, in the form of director
switches in each arm. This converter is able to generate a multi-level AC voltage and, since its stacks of cells consist of H-bridge cells
instead of half-bridge cells, they are able to generate higher AC voltage than the DC terminal voltage. This allows the AAC to operate
at an optimal point, called the “sweet spot”, where the AC and DC energy flows equal. The director switches in the AAC are responsible
for alternating the conduction period of each arm, leading to a significant reduction in the number of cells in the stacks. Furthermore,
the AAC can keep control of the current in the phase reactor even in case of a DC-side fault and support the AC grid, through a
STATCOM mode. Simulation results and loss calculations are presented in this paper in order to support the claimed features of the
AAC
The transmission of electric power has to take place in the most efficient way in addition to providing flexibility in the process. Flexible A.C. Transmission System (FACTS) promotes the use of static controllers to enhance the controllability and increase the power transfer capability. Providing reactive shunt compensation with shunt-connected capacitors and reactors is a well-established technique to get a better voltage profile in a power system. Shunt Capacitors are inexpensive but lack dynamic capabilities, thus some form of dynamically controlled reactive power compensation becomes essential. In this paper, three phase Distribution Static Var Compensator (D-SVC) has been developed and studied under different conditions. Open loop mode and closed loop mode of operation of D-SVC is simulated and studied. The work presented here is very much useful for distribution system, for effective reactive power management and better Voltage control.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Implementation Of Thyristor Controlled Series Capacitor (TCSC) In Transmissio...IJERA Editor
A grid of transmission lines operating at high or extra high voltages is required to transmit power from
generating stations to load. In addition to transmission lines that carry power from source to load, modern power
systems are highly interconnected for economic reasons. The large interconnected transmission networks are
prone to faults due to the lightning discharges and reduce insulation strength. Changing of loads and atmosphere
conditions are unpredictable factors. This may cause overloading of lines due to which voltage collapse takes
place. These problems can be eased by providing sufficient margin of working parameters and power transfer,
but it is not possible due to expansion of transmission network. Still the required margin is reduced by
introduction of fast dynamic control over reactive and active power by high power electronic controllers. This
paper describes about implementation of Thyristor Controlled Series Capacitor (TCSC) in transmission line
model in order to enhance power flow at the receiving end. The triggering pulses to the thyristor are given using
Arduino.
A High Performance PWM Voltage Source Inverter Used for VAR Compensation and ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
The DC-fault Blocking Capability by a New Hybrid Multilevel Converter in HVDC...Editor IJCATR
This paper explains the working principles, supported by simulation results, of a new converter topology in-tended for HVDC
application, called the Alternate Arm Con-verter (AAC). Modular Multilevel Converters deliver small footprints and efficiencies above
99% in their half-bridge format, but only deliver DC-fault blocking with full-bridge sub-modules, and with an unacceptable penalty in
efficiency. The Alternate Arm Converter (AAC) is a hybrid circuit topology using a mixture of full-bridge sub-modules and director
switches which is capable of current control through DC faults while maintaining good efficiency in normal operation. It is hybrid
between the modular multi-level converter, because of the presence of H-bridge cells, and the 2-level converter, in the form of director
switches in each arm. This converter is able to generate a multi-level AC voltage and, since its stacks of cells consist of H-bridge cells
instead of half-bridge cells, they are able to generate higher AC voltage than the DC terminal voltage. This allows the AAC to operate
at an optimal point, called the “sweet spot”, where the AC and DC energy flows equal. The director switches in the AAC are responsible
for alternating the conduction period of each arm, leading to a significant reduction in the number of cells in the stacks. Furthermore,
the AAC can keep control of the current in the phase reactor even in case of a DC-side fault and support the AC grid, through a
STATCOM mode. Simulation results and loss calculations are presented in this paper in order to support the claimed features of the
AAC
The transmission of electric power has to take place in the most efficient way in addition to providing flexibility in the process. Flexible A.C. Transmission System (FACTS) promotes the use of static controllers to enhance the controllability and increase the power transfer capability. Providing reactive shunt compensation with shunt-connected capacitors and reactors is a well-established technique to get a better voltage profile in a power system. Shunt Capacitors are inexpensive but lack dynamic capabilities, thus some form of dynamically controlled reactive power compensation becomes essential. In this paper, three phase Distribution Static Var Compensator (D-SVC) has been developed and studied under different conditions. Open loop mode and closed loop mode of operation of D-SVC is simulated and studied. The work presented here is very much useful for distribution system, for effective reactive power management and better Voltage control.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
SIMULATION STUDY OF QZSI Z-SOURCE INVERTER FOR RESISTIVE AND INDUCTIVE LOADijiert bestjournal
This paper involves design and simulation of a step up dc/dc converter topology connected with the chopper circuit
intended for resistive and inductive load. The topology contains voltage fed qzsi Z Source Inverter (qzsi), a high
frequency isolation transformer with reduced turn’s ratio, a Voltage Doubler Rectifier (VDR). A carrier based PulseWidth
Modulation (PWM) which employs shoot through state strategy for qzsi is implemented which gives significantly
high voltage gain compared to traditional PWM techniques. To improve the power density of converter, three phase aclink
and three-phase VDR is implemented. The designed step up dc/dc converter is tested for various kinds of resistive
and inductive load in MATLAB/SIMULIKN platform.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Influence of Static VAR Compensator for Undervoltage Load Shedding to Avoid V...IJAPEJOURNAL
In the recent years, operation of power systems at lower stability margins has increased the importance of system protection methods that protect the system stability against various disturbances. Among these methods, the load shedding serves as an effective and last-resort tool to prevent system frequency/voltage instability. The analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, voltage also needs to be taken into account in load shedding schemes. This paper considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location .The amount of load to be shed from each bus is decided using the fixed step size method and it’s location has been identified by using voltage collapse proximity index method. SVC is shunt connected FACTS device used to improve the voltage profile of the system. In this paper impact of SVC on load shedding for IEEE 14 bus system has been presented and analyzed.
This paper investigates the performance of line commutated converter (LCC) based monopolar
HVDC transmission system feeding a weak AC network with hybrid reactive power compensators (RPC’s) at the
inverter AC side. The hybrid compensator is an equal mix of any two of the following compensators:
synchronous compensator (SC); static var compensator (SVC); static synchronous compensator (STATCOM).
The HVDC transmission system model is implemented in the Matlab with the firefly algorithm based optimal
proportional integral (PI) controller for rectifier and inverter control. The transient performances of hybrid
RPC’s (SC+SVC, SVC+STATCOM and SC+STATCOM) are judged under various fault conditions and the
outcomes are compared with the performance of the SC, SVC and STATCOM to highlight the supremacy of the
hybrid compensators. The simulation results validate that the equal mix of SC and STATCOM has a steady and
fastest response. The results also demonstrate the superiority of the firefly algorithm based optimal PI
controller over the conventional PI controller. The harmonic analysis is also carried out under steady state
operation to assure the quality of power supply on the inverter AC side
A Novel Hybrid Dstatcom Topology for Load Compensation with Non-Stiff SourceIJERA Editor
The distribution static compensator (DSTATCOM) is a shunt active filter, which injects currents into the point
of common coupling (PCC) (the common point where load, source, and DSTATCOM are connected) such that
the harmonic filtering, power factor correction, and load balancing can be achieved. The distribution static
compensator (DSTATCOM) is used for load compensation in power distribution network. A new topology for
DSTATCOM applications with non-stiff source is proposed. The proposed topology enables DSTATCOM to
have a reduced dc-link voltage without compromising the compensation capability. It uses a series capacitor
along with the interfacing inductor and a shunt filter capacitor. With the reduction in dc-link voltage, the
average switching frequency of the insulated gate bipolar transistor switches of the D-STATCOM is also
reduced. Consequently, the switching losses in the inverter are reduced. Detailed design aspects of the series and
shunt capacitors are discussed in this paper. A simulation study of the proposed topology has been carried out
using MATLAB environment and the results analyzed.
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
Asymmetrical Cascaded Multi Level Inverter using Control Freedom Pulse width ...IAES-IJPEDS
In this paper, the suggested topologies are gained by cascading a full bridge inverter with dissimilar DC sources. This topology has several new patterns adopting the fixed switching frequency, multicarrier control freedom degree with mixture conceptions are established and simulated for the preferred three-phase cascaded multilevel inverter. In outstanding switching arrangement terminations, there are convinced degrees of freedom to produce the nine level AC output voltages with terminated switching positions for producing altered output voltages. These investigations focus on asymmetrical cascaded multilevel inverter engaging with carrier overlapping pulse width modulation (PWM) topologies. These topologies offer less amount of harmonics present in the output voltage and superior root mean square (RMS) values of the output voltages associated with the traditional sinusoidal pulse width modulation. This research studies carries with it MATLAB/SIMULINK based simulation and experimental results obtained using appropriated prototype to prove the validity of the proposed concept.
Abstract:-This paper deals with open loop study of fixed capacitor thyristor controlled reactor (FC-TCR) system simulation using Matlab/Simulink for various loading. The modelling of the FC-TCR is verified using the Matlab/Simulink. First power flow results are obtained and power profile have been studied for an uncompensated then results are compared with the results obtained after compensating using the FC-TCR.Its observed that current drawn by FC-TCR is varied by changing firing angle. In compensation without FC-TCR, load increases and power factor become less and in compensation with FC-TCR, load increases and power factor become near to the unity.Hence by providing compensation Voltage, power profile of system will be improved and system losses are reduced.
ENHANCEMENT OF ACTIVE POWER FLOW CAPACITY OF A TRANSMISSION LINE USING MSC‐TC...ijiert bestjournal
This paper represents the MSC-TCR scheme of shun t compensation used in FACTS. The laboratory setup of the SVC circuit using a Thyristor controlled reactor in parallel with mechanically switched capacitor will discussed in this paper. Results from the lab setup to exhibit firing angle adjustment to inject or absorb VAr into the system will also be described. During the process,losses happened are also discussed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
SIMULATION STUDY OF QZSI Z-SOURCE INVERTER FOR RESISTIVE AND INDUCTIVE LOADijiert bestjournal
This paper involves design and simulation of a step up dc/dc converter topology connected with the chopper circuit
intended for resistive and inductive load. The topology contains voltage fed qzsi Z Source Inverter (qzsi), a high
frequency isolation transformer with reduced turn’s ratio, a Voltage Doubler Rectifier (VDR). A carrier based PulseWidth
Modulation (PWM) which employs shoot through state strategy for qzsi is implemented which gives significantly
high voltage gain compared to traditional PWM techniques. To improve the power density of converter, three phase aclink
and three-phase VDR is implemented. The designed step up dc/dc converter is tested for various kinds of resistive
and inductive load in MATLAB/SIMULIKN platform.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Influence of Static VAR Compensator for Undervoltage Load Shedding to Avoid V...IJAPEJOURNAL
In the recent years, operation of power systems at lower stability margins has increased the importance of system protection methods that protect the system stability against various disturbances. Among these methods, the load shedding serves as an effective and last-resort tool to prevent system frequency/voltage instability. The analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, voltage also needs to be taken into account in load shedding schemes. This paper considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location .The amount of load to be shed from each bus is decided using the fixed step size method and it’s location has been identified by using voltage collapse proximity index method. SVC is shunt connected FACTS device used to improve the voltage profile of the system. In this paper impact of SVC on load shedding for IEEE 14 bus system has been presented and analyzed.
This paper investigates the performance of line commutated converter (LCC) based monopolar
HVDC transmission system feeding a weak AC network with hybrid reactive power compensators (RPC’s) at the
inverter AC side. The hybrid compensator is an equal mix of any two of the following compensators:
synchronous compensator (SC); static var compensator (SVC); static synchronous compensator (STATCOM).
The HVDC transmission system model is implemented in the Matlab with the firefly algorithm based optimal
proportional integral (PI) controller for rectifier and inverter control. The transient performances of hybrid
RPC’s (SC+SVC, SVC+STATCOM and SC+STATCOM) are judged under various fault conditions and the
outcomes are compared with the performance of the SC, SVC and STATCOM to highlight the supremacy of the
hybrid compensators. The simulation results validate that the equal mix of SC and STATCOM has a steady and
fastest response. The results also demonstrate the superiority of the firefly algorithm based optimal PI
controller over the conventional PI controller. The harmonic analysis is also carried out under steady state
operation to assure the quality of power supply on the inverter AC side
A Novel Hybrid Dstatcom Topology for Load Compensation with Non-Stiff SourceIJERA Editor
The distribution static compensator (DSTATCOM) is a shunt active filter, which injects currents into the point
of common coupling (PCC) (the common point where load, source, and DSTATCOM are connected) such that
the harmonic filtering, power factor correction, and load balancing can be achieved. The distribution static
compensator (DSTATCOM) is used for load compensation in power distribution network. A new topology for
DSTATCOM applications with non-stiff source is proposed. The proposed topology enables DSTATCOM to
have a reduced dc-link voltage without compromising the compensation capability. It uses a series capacitor
along with the interfacing inductor and a shunt filter capacitor. With the reduction in dc-link voltage, the
average switching frequency of the insulated gate bipolar transistor switches of the D-STATCOM is also
reduced. Consequently, the switching losses in the inverter are reduced. Detailed design aspects of the series and
shunt capacitors are discussed in this paper. A simulation study of the proposed topology has been carried out
using MATLAB environment and the results analyzed.
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
Asymmetrical Cascaded Multi Level Inverter using Control Freedom Pulse width ...IAES-IJPEDS
In this paper, the suggested topologies are gained by cascading a full bridge inverter with dissimilar DC sources. This topology has several new patterns adopting the fixed switching frequency, multicarrier control freedom degree with mixture conceptions are established and simulated for the preferred three-phase cascaded multilevel inverter. In outstanding switching arrangement terminations, there are convinced degrees of freedom to produce the nine level AC output voltages with terminated switching positions for producing altered output voltages. These investigations focus on asymmetrical cascaded multilevel inverter engaging with carrier overlapping pulse width modulation (PWM) topologies. These topologies offer less amount of harmonics present in the output voltage and superior root mean square (RMS) values of the output voltages associated with the traditional sinusoidal pulse width modulation. This research studies carries with it MATLAB/SIMULINK based simulation and experimental results obtained using appropriated prototype to prove the validity of the proposed concept.
Abstract:-This paper deals with open loop study of fixed capacitor thyristor controlled reactor (FC-TCR) system simulation using Matlab/Simulink for various loading. The modelling of the FC-TCR is verified using the Matlab/Simulink. First power flow results are obtained and power profile have been studied for an uncompensated then results are compared with the results obtained after compensating using the FC-TCR.Its observed that current drawn by FC-TCR is varied by changing firing angle. In compensation without FC-TCR, load increases and power factor become less and in compensation with FC-TCR, load increases and power factor become near to the unity.Hence by providing compensation Voltage, power profile of system will be improved and system losses are reduced.
ENHANCEMENT OF ACTIVE POWER FLOW CAPACITY OF A TRANSMISSION LINE USING MSC‐TC...ijiert bestjournal
This paper represents the MSC-TCR scheme of shun t compensation used in FACTS. The laboratory setup of the SVC circuit using a Thyristor controlled reactor in parallel with mechanically switched capacitor will discussed in this paper. Results from the lab setup to exhibit firing angle adjustment to inject or absorb VAr into the system will also be described. During the process,losses happened are also discussed.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Social Media: Deciphering Network Personas For Your B2Bemagine
When it comes to social media most marketers admittedly lack a cohesive strategy. With literally hundreds of options to leverage social channels, a clearly defined strategy is critical. Because of the many social networks to choose from, it’s not always easy to figure out which ones your B2B should be on or which ones should be eliminated from your strategy all together.
Because we often see this lack of strategy and vision with our own clients, we are excited to announce the 2nd installment of our B2B Webinar Series, entitled: Social Media: Deciphering Network Personas For Your B2B. Led by our Social Media Specialist, Hannah Beacham, this session will focus on creating the right Social Media strategy based on the B2B’s target audience and how to follow Social Media’s golden rules.
During the webinar, Hannah will pin point some of the common social media mistakes for B2B as well as what you can expect from a well thought out strategy. Webinar topics include:
• Explanation of Each Network’s Role In Your B2B Strategy
• B2B Statistics on the Social Media Leading Players
• A Sample Marketing Plan Utilizing Each Network
Стратегия, маркетинг и брендинг в розничном и ресторанном бизнесе.
Инновационные розничные форматы, опыт самого развитого ретейл рынка США в создании уникальных форматов и удержании покупателей.
Эффективные маркетинговые кампании в рознице. Как привлечь и удержать покупателей в период кризиса.
Создание ретейл-бренда в HoReCa. Не делайте
модно. Не делайте логотип. Делайте для людей.
Enhancement of Power Quality by an Application FACTS DevicesIAES-IJPEDS
The paper narrates widespread use of electrical energy by modern civilization has necessitated producing bulk electrical energy economically and efficiently. The Flexible AC Transmission system (FACTS) is a new technology based on power electronics, which offers an opportunity to enhance controllability, stability, and power transfer capability of AC transmission systems. Here SVC has been developed with the combination of TCSC and TCR. The paper contains simulation models of Thyristor controlled Series Capacitor (TCSC) and Thyristor controlled Reactor (TCR)- based Static VAR Compensator (SVC) which are the series and shunt Flexible AC Transmission Systems (FACTS) devices. The fact devices are designed by considering the line losses and their stability. The design and simulations of TCSC and TCR-based SVC shows the effectiveness of result using the MATLAB/Simulink. The designed system will try to reduce the voltage drops and electrical losses in the network without the possibility of transient especially in case of long transmission system. Student feedback indicates that this package is user-friendly and considerably effective for students and researchers to study theory of controlled reactor compensators, series capacitor compensator, and the reactive power control and voltage regulation
Thyristor Controlled Series Capacitor with Automatic Controlijiert bestjournal
An increasingly competitive market where economic a nd environmental pressures limit their scope to expand transmission facilities.The optimiz ation of transmission corridors for power transfer has become a great importance. In this sce nario,the FACTS technology is an attractive option for increasing system operation flexibility [1],New developments in high-current,high- power electronics are making it possible to control electronically the power flows on the high voltage side of the network during both steady stat e and transient operation. In this paper a series controller from the Flexible AC Transmission System (FACTS) family called as �Thyristor Controlled Series Capacitor� (TCSC) is designed using PIC microcontroller. Thyristor controlled series compensator (TCSC),is the first generation of FACTS controller,can govern line impedance through introduction of a thy ristor controlled capacitor in series with the transmission line. A grid of transmission lines ope rating at high voltages is required to transmit power from generating stations to load. In addition to transmission lines that carry power from source to load,modern power systems are highly int erconnected for economic reasons.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Enhancement of Power System Dynamics Using a Novel Series Compensation SchemeIJMER
Phase imbalanced capacitive compensation is a “hybrid” series compensation scheme, where the
series capacitive compensation in one phase is created using a single-phase TCSC in series with a fixed capacitor
(Cc), and the other two phases are compensated by fixed series capacitors (C). The TCSC control is initially set
such that its equivalent compensations at the power frequency combined with the fixed capacitor yield a
resultant compensation equal to the other two phases. Thus, the phase balance is maintained at the power
frequency while at any other frequency, a phase imbalance is created. The effectiveness of the scheme in damping
power system oscillations for various network conditions, namely different system faults and tie-line power flows is
evaluated using the MATLAB/SIMULINK Software
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
CONTROL OF BATTERY OPERATED SYSTEM WITH A DC-DC BOOSTCONVERTER FED DSTATCOM U...ijiert bestjournal
This paper presents a comprehensive survey of DSTATCOM control strategies put forward recently. It is
aimed at providing a broad perspective on the status of DSTATCOM control methods to researchers and
application engineers dealing with harmonic suppression issues. Many control techniques have been
designed, developed, and realized for active filters in recent years. The proposed DSTATCOM consists of a
three-leg Voltage Source Converter (VSC) with a dc bus capacitor. The PV array or battery operated boost
converter is proposed to maintain the dc link voltage of the dc bus capacitor for continuous compensation
for the load. This paper presents to evaluate the performance comparison of two control strategies for
extracting the reference currents to control the proposed DSTATCOM. The two control methods are
Synchronous Reference Frame (SRF) theory and IcosΦ algorithm. The performance of the DSTATCOM is
validated using MATLAB software with its simulink and Power System Block set (PSB) toolboxes. The
simulation results for the two control methods are compared to validate the superior performance of the
IcosΦ algorithm.
Modelling and Simulation of Facts Devices TCSC and SVC for A 11 Bus Power Systemijtsrd
Due to the ever increasing demand for power and the growth of the transmission network, transmission lines must now be operated under load, posing a danger of power flow control and voltage instability. This study proposes using TCSC and SVC devices to control power flow in a power system network. The TCSC is a series compensated device that lowers transmission line reactance and improves power flow, whereas the SVC is a shunt compensated device that improves voltage profile. This paper describes a method for modelling and simulation with MATLAB SIMULINK Sim power System block set . For power flow management and voltage stability limit, the appropriate position of TCSC and SVC devices is evaluated. The proposed method is implemented on a two area four machine 11 bus test system model, and the simulated results are shown to validate the test case system. The performance of the TCSC and SVC devices is evaluated in this study, and the simulated results are compared for better power flow regulation in the power system. Vinit K Sharma | Namrata Sant "Modelling and Simulation of Facts Devices (TCSC and SVC) for A 11 Bus Power System" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-5 , August 2022, URL: https://www.ijtsrd.com/papers/ijtsrd50395.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/50395/modelling-and-simulation-of-facts-devices-tcsc-and-svc-for-a-11-bus-power-system/vinit-k-sharma
DG FED MULTILEVEL INVERTER BASED D-STATCOM FOR VARIOUS LOADING CONDITIONSIJCI JOURNAL
During the past few decades, power industries have proved that the adverse impacts on the PQ can be
mitigated or avoided by conventional means, and that technique using fast controlled force commutated
power electronics (PE) are even more effective. PQ compensators can be categorized into two main types.
One is shunt connected compensation device that effectively eliminates harmonics. The other is the series
connected device, which has an edge over the shunt type for correcting the distorted system side voltages
and voltage sags caused by power transmission system faults. The STATCOM used in distribution systems
is called DSTACOM (Distribution-STACOM) and its configuration is the same, but with small
modifications. Recent advances in the power-handling capabilities of static switch devices such as 3.3kV,
4.5kV, and 6.5kV Insulated Gate Bipolar Transistors (IGBTs) with voltage rating commercially available,
have made the use of the voltage source inverters (VSI) feasible for high-power applications. High power
and high-voltage conversion systems have become very important issues for the power electronic industry
handling the large ac drive and electrical power applications at both the transmission and distribution
levels. For these reasons, new families of multilevel inverters have emerged as the solution for working
with higher voltage levels. Multilevel inverters (MLI) include an array of power semiconductors and
capacitor voltage sources, the output of which generate voltages with stepped waveforms. These converter
topologies can generate high-quality voltage waveforms with power semiconductor switches operating at a
frequency near the fundamental. It significantly reduces the harmonics problem with reduced voltage stress
across the switch. This research work is mainly focusing on application of multilevel DSTATCOM for
power quality improvement in distribution system with integration of RES. Matlab/Simulink based model is
developed and simulation results are presented.
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.
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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.
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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.
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• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
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• 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.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
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.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
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Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
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Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
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
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1. 2004 IEEEIPES Transmission8 DistributionConference & Exposition: LatinAmerica
1
GCSC - Gate Controlled Series Capacitor: a
New Facts Device for Series Compensation of
- . . - .
'lransmissionLines
E. H. Watanabe, Senior Member, IEEE, L. F. W.de Souza, Member, IEEE, F. D. de Jesus,
J. E. R. Alves, Member, IEEE and A. Bianco,Member, IEEE
Abstract -Controllableseries compensationis a useful tech-
nique to increase tbc efficiency of operation of existingtransmis-
sion lines and improve overall power system stability. Up to date,
the TCSC is the most adopted solution whenever controllable
series compensationis required. This paper introduces the Gate
Controlled Series Capacitor (GCSC), a novel FACTS device for
series compensation. The principle of operation and some pro-
spective applications of the equipment nre presented. Special
attention is given to the duaIityof the GCSCwith the well-known
thyristor controlled renctor, used for sbunt compensation. It is
shown that the GCSC can be more attractive than the TCSC in
most situations. Simulation results illustrate the time response of
the equipment and its ability to control power flow in a transmis-
sion line. Finally, technology issues regarding high power self
commutatingvalves are discussed.
Ztidex TermsScries Compensation, TCSC, GCSC, FACTS.
I. INTRODUCTION
owadays, it is becoming increasingly difficult to build
new transmission lines, due to restrictions regarding en-
vironment and financial issues. Besides that, electrical
energy consumption continues to increase, leading to a situa-
tion where utilities and independent system operators have ta
operate existing transmission systems much more efficiently
and closer to their stability limits. One important benefit of
FACTS (Flexible AC Transmission Systems) technology is
that it makes it possible to improve the use of the existing
power transmission system and to postpone or avoid the con-
structionof new transmission facilities.
Among FACTS devices, those for series compensation
play an important role in a country as Brazil, where long
transmission lines connect remote hydro-generation plants to
Iarge urban areas. Conventional series compensation, provided
by f i e d capacitor bank, is a useful tool to improve the power
transfer capacity by neutralizing part of the seriesreactance of
transmission lines [I]. With the new controlled series compen-
sators, it is possible not only to control the power flow
through transmission lines, avoiding power flow loops, but
N
E. H. Watauabe andF.D.de Jesus anwith the Federal University of Rio
L. F.W. de Souzaand J. E.R.Alves are with Cepel, Rio de Janeiro, RJ.
A. Bianco is with Andrade e Cauellas Consulting, S a Paulo, SP,Brasil
de Jaaeiro, Rio de Janeiro,RJ, Brasil( watanahe@ufj.br;fabio@coe,uf?.br).
Brasil (Ifclipe@cepel.br; alves@cepel.br).
(andre.bianco@andradecanellas.com.br).
also to improve power system stability, through the fast ac-
tuation of its control loops after disturbances. Moreover, re-
cent changes in the power industry throughout the world in-
creased the interest in equipment capable of control power
flow through pre-determined paths, meeting transmission
contract requirements even in highly meshed systems.
Thyristor Controlled Series Compensators (TCSC) were
the first generation of series compensation FACTS devices.
Actually, TCSC may be credited as a cornerstone of FACTS
deveIopment, as the first equipment developed under the
FACTS concept. TCSC are made of a parallel connection of a
capacitor and a thyristor-controlled reactor [2]. In fact, the
TCSC is simply a static voltage controller (SVC) [3] con-
nected in series with a transmission line. The thyristor is its
switching device. Existing TCSC installation in the world and
in Brazil already proved the efficiency and robustness of the
equipment. Although the TCSC is capable of continuously
adjust its reactance, it has the disadvantage of presenting a
parallel resonance between the capacitor and the thyristor
controlled reactor at the fundamental frequency, for a given
firing angle of the thyristor. Also, the variation range of the
reactance presented by the TCSC is somewhat narrow.
This paper presents a novel equipment for controlled series
compensation: the Gate Controlled Series Capacitor (GCSC)
[4]. The GCSC, shown in Fig. 1, based on a concept first in-
troduced by Kurudy et al. [SI, is made simply of a capacitor
and a pair of self-cornmutated semiconductor switches in anti-
parallel, e.g., the GTO (Gate Tum-off Thyristor) or the IGCT
(Wegrated Gate Commutated Thyristor) [6]. It is capable of
continuously vary its reactance from zero to the maximum
compensation provided by the capacitor. The GCSC is simpler
Fig. I -TheGate ControolledSeries Capacitor4 C S C .
0-7803-8775-9/041$20.00 02004 IEEE 981
Authorized licensed use limited to: UNIVERSIDADE DO PORTO. Downloaded on April 22,2010 at 14:46:55 UTC from IEEE Xplore. Restrictions apply.
2. 2
Fig. 2-Typical voltage and currentwaveforms of theGCSC
than the TCSC, utilizes a smaller capacitor, does not need any
reactor and, differently from the TCSC, does not have an in-
trinsic internal resonance. For these reasons, the GCSC may
be a better solution in most situationswhere controlled series
compensation is required. One potentially interesting applica-
tion of the GCSC is in the retrofitting of existing fixed series
capacitors, making them FACTS devices. Another FACTS
devices developed for series compensation is the SSSC (Static
Synchronous Series Compensator) which is based on voltage
source converters .[2]. This device presents high flexibility
level but has a much higher cost involved due to the complex-
ity of the converters.
This paper presents the GCSC, its main components, prin-
ciple of operation, typical waveforms and main applications.
An important issue discussed in this paper is the duality of the
GCSC with the well-known TCR,largely used in static com-
pensation.Some rating comparisons with the TCSC are pre-
sented, showing that the GCSC may have several advantages
over the TCSC. Technological problems and possible trends
relating to the development of high-voltage and high-current
self-commutated valves ate also discussed. Results of ATP
digital simulations are presented, showing time-responses of
the GCSC and proving its effectiveness in controlling power
ffow through a meshed transmission system.
11. GATECONTROLLED SERIESCAPACITOR
A. Principle ofOperalion
From Fig. 1, one can see that if the self-cornmutated
switches turn off,the capacitor is inserted in the circuit, com-
pensating the line inductance. When the switches are turned
on, the capacitor is bypassed, canceling the compensation ef-
fect. The switches start to conduct only when their anode-
cathode voltage tends to become positive, exactly when the
capacitor voltage vc is zero. The line current i of the con-
trolled power line flows altemately through the switches and
the series capacitor.
The level of series compensation is given by the funda-
mental component of the capacitor voltage VC. This level may
be varied by controlling the blocking angle y of the semicon-
-I
90 100 110 120 130 140 150 160 170 180
Y (degrees)
Pig.3 -F u n k n t a limpedanceof the GCSC asa functionof theblocking
angle
ductor switches. This blocking angle y is measured from the
zero crossing of the line current. Fig. 2 shows typical current
and voltage waveforms for the GCSC of Fig. 1, for a given
blocking angle y. It is assumed that the transmissionline cur-
tent, i,is sinusoidal. In order to avoid dc voltage components
in the series capacitor, during normal operation, the blocking
angley should be greaterthan 90" and smaller than 180'.
Fig. 3 shows the relation between the fundamental imped-
ance of the GCSC and the blocking angley. A blocking angle
of 90" means that the capacitor is fully inserted in the circuit,
that is, the fundamental impedance is 1p.u and the switches
are turned off completely. On the other hand, ifthe blocking
angle is 180",the switches are on full conduction, bypassing
the capacitor, meaning a zero impedance. So, a continuous
variation of the equivalent series capacitance of the GCSC is
achievable in the range of 90"<y < 180".
Referring again to Fig. 2, one can see that the voltage
waveform in the capacitor is non-sinusoidal. Fig. 4 shows the
main harmonic components of the voltage waveforms as a
function of the blocking angle y. The voltages are in per-unit
values of the capacitor maximum voltage. As the voltage in
the GCSC is lower thanthe system voltage, depending on the
compensation level, the harmonics will be proportionally
lower, in percent values, when converted to the system basis.
B. Prospective Applications
The GCSC could be typically used in applicationswhere a
TCSC is used today, mainly in the control of power flow and
damping of power oscillations. The GCSC may operate with
an open Ioop configuration,where it would simply control its
reactance, or in closed loop, controllingpower flow or current
in the line, or maintaining a constant compensation voltage
[2]. Power Oscillation Damping schemes may also be easily
HannonlcsInlike GCSC0.2, I
o w ,U1
4 2
90 100 110 120 130 140 150 160 170 180
Y (&grreS)
Fig.4 - Harmonicvoltages in the GCSCas a functionof the blockingangley.
982
Authorized licensed use limited to: UNIVERSIDADE DO PORTO. Downloaded on April 22,2010 at 14:46:55 UTC from IEEE Xplore. Restrictions apply.
3. 3
D Semiconductorswitchesin
L Seriesconnectedto transmis-
ISuppliedby a currentsource
ISwitches control amountof
parallelwitb a capacitor
sionlines
current in the caDacitor
attainable with the GCSC.
The typical configuration of the GCSC would be a system
composed of smaller devices connected in series, in a so-
called multi-module configuration. In this configuration, the
semiconductor valves have lower voltages and voltage har-
monic distortions are kept low.
The comparison between a GCSC and a TCSC will favor
the fmt equipment in most situations where controllable series
compensation is needed (see Section III). As research on the
GCSC is still under way, it is possible that a break-even MVA
rating is found, above which the TCSC will be more advanta-
geous due to possible valves and protection requirements of
the GCSC. The authors foreseen that the GCSC should also be
a very interesting alternative for retrofitting fixed series ca-
pacitor installations,making them FACTS devices.
S&condu& switches in
Shunt connectedto transmis-
Suppliedby avoltage source
Switches control amount of
serieswitha reactor
sion lines
voltagein the reactor
HI. DUALITYwml TZIETHYRISTOR CONTROLLEDREACTOR
One interesting feature of the GCSC is that its operation is
exactly the dual of the well-known thyristor Controlled reactor
( E R ) [2][3], used for shunt compensation, usually with a
fKed capacitor in parallel. In fact, one may easily observe that
the voltage waveform of the GCSC shown in Fig. 2 is similar
to current waveforms of the TCR (e.g., see [2] and [3]). Table
1shows a comparison between the dual characteristics of both
equipment. The duality can easily be extended to the valves
[7],making it easier to understand the requisites of a GCSC
valve. Considering that the TCR is the dual of the GCSC and
that the former is a longtime adopted solution for controlled
shunt compensation, one may conclude that the GCSC is the
naturalsolution for controlled seriescompensation.
TABLE1-DUALCHARACTERlSTlCSOF THEGCSC AND THE TCR
Gate Controlled Series CapacitorI ThyristorCothUed Reactor
e Voltage controlledby switches'
ISwitches 6re and block with
blocking angle
zerovoltage
Current controlledby switches'
Switchesfire and blockwitb
m gansle
zero current
A. Main Components
A simple comparison of rating of theGCSC and the widely
adopted TCSC is presented here. For this analysis, although
the TCSC may be designed to operate in the inductive region,
it is assumed that it normally operates only in the capacitive
region. Also, it is considered that the maximum compensation
capacity is equal for both devices: they should have the same
maximum capacitive impedance when compensating at their
maximum.
Fig. 5 shows a typical impedance curve for a TCSC, as a
/I- II
+
-2
ctmn 183
~ringalgleNdeim=)
Fig. 5- Typical impedancecharacteristicof theTCSC.
function of the firing angle a.The region where operation is
allowed is shaded. The resonance is also shown in this figure.
Z,, and Z,, are the maximum and minimum values of the
impedance of the TCSC operating in the capacitive region.
Z,, corresponds to the capacitive reactance oniy, that is, at
this point the thyristors do not conduct and the reactor is not
present. Z,, corresponds to the value of equivalent imped-
ance of the capacitor and the thyristor controlled reactor for
the minimum fuing angle ami,,.This angle is limited in order
to avoid the potentially dangerous operation near the parallel
resonance region.
For the GCSC, the minimum reactance is equal to zero.
The maximum reactance, which corresponds to the capacitor
reactance, should be equal to Zmxof the TCSC to obtain the
same maximum compensation level. The relationship between
capacitances of both devices is the following:
(1)
CCLX - 2"
CTCX zm,
Moreover, the same steady-state voltage is applied to both
the TCSC and GCSC capacitors. As for the current, it is al-
ways higher in the TCSC than in the GCSC [XI, as the paral-
lel-connected TCR needs to boost the capacitor current in or-
der to increase the capacitor voltage.
Besides needing a larger capacitor, the TCSC will also
need a reactor that should be rated for the same current of the
valve. As a general conclusion, the GCSC needs less passive
components, as its capacitor is much smaller, with lower cur-
rent rating, and it does not need any reactor at all.
The valve currents in the TCSC are always higher for de-
vices where the relation between the maximum and minimum
impedance is greater than 2, what happens in most of the ex-
istent installations throughout the world [2][8]. On the other
hand, the GCSC valves should be rated for a voltage slightly
higher [XI.
B. Example ofcomparison ~ the BruziIiunNorth-South Inter-
connection
To illustrate the previous conclusions, a GCSC was rated to
prospectively substitute one of the TCSC already installed in
the Brazilian North-South Interconnection [SI.This transmis-
sion line needs a seriescontroller to damp out a low frequency
power oscillation between Brazilian North and South grids.
The existent TCSC has a reactive power rating of IDS Mvar
and is installed in a 550 kV transmission line with a rated CUT-
rent of 1500A. This equipment normally operates with a ca-
pacitive reactance of 15.92 0, when there is no need of
L
983
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4. 4
Fig. 6 -GCSCconnectedto acurrent source
damping power swings.
For rating purposes, it was assumed that the GCSC should
have the same maximum reactance and nominal Mvar of the
TCSC. Also, it was assumed that the GCSC operates at the
same continuous effective reactance of the TCSC. It should be
pointed out that, althoughboth devices have the same function
in the power system, they are quite different. For this reason,
other designing strategies are possible for the GCSC, but it is
beyond the scope of this paper to find an optimal designing
strategy. Table 2 Summarizes the basic characteristics of the
existing TCSC and a GCSCproposed to substituteit.
TABLE 2-EXISTENT TcsCA N D PROFQSED wscRATINGS FOR %AZIUAN
NORTH-SOUTHINTERCONNECTION
Parameter TCSC I ccsc j
CapacitorReactance 13.27i2 39.81R
Capacitance 200 p 66.6 pF
Max.Reactance 39.81 Q 39.81Q
DynamicControl Range 13.27-39.81Cl 0 -39.81 R
Max. Fundamental Voltage 59.7kV 59.7kV
Max.RMS Voltage 60.3kV 59.7kV
Max. RMS Capacitor Current 5025 A 1500A
Max. Valve Current(rms) 3735A 1500A
Max.Reactor Current (rms) 3735A no reactor
Mm.Voltage ofthe Valves 51.34I 59.73/
(rindpeak) 74.41kV 84.47kV
1.5
(kv)
1
0.5
0
4 . 5
-1
-1.5 0 0.1 0.2 0.3 0.4 t
Time ( 5 )
E I. [ FI20')-I200 FI 50'
rFig.7 -Timeresponseof a GCSC connected to a current source
17KlD1 , , , , I15WO
0 6 0 8 I 1.2 1 4 1 6 i a
time ( 5 )
Pig.8 -Openloopresponsesof the GCSC and TCSCwithlow levels of com-
pensation,varyingf"35% to45% at 800 ms,andback to35% at 1.3s
v. RE-SULTSOF DIGITAL fhdlLATIONS
A. Time Responses
The GCSC can rapidly vary its reactance, whenever its
blocking angle signal is varied. To demonstrate that, a simple
system was modeled in the ATP simulation package, consist-
ing of a GCSC fed by a current source, as shown in Fig. 6.
The GCSC has a maximum reactance of 26.5 R. Initially, the
self-commutated switches are operating with a blocking angle
of 120". At Zooms, the compensation level is decreased by
increasing the blocking angle to 150'. Then, at Moms, the
compensation level is returned to the initial value. The result
of the simulation is shown in Fig. 7.
The topology shown in Fig. 6, although very simple, is in-
teresting to analyze the dynamic behavior of the equipment, as
the only other element in the network is an ideal current
source. The same topology is used in the ATP to test both the
GCSC and TCSC of Table 2. The current source now has an
rms magnitude of 1500A. In the fust simulation, each equip-
ment is compensating at low level (35% of X-). Next, the
compensation increases to 45% and decreases again to 35%.
Fig. 8 shows the fundamental voltage response of each
equipment to this input. Both equipment have similar open
loop responses at this level of compensation.
Another simulation was performed, with higher levels of
=z%?ow40000
0 6 0 8 1 1 2 1 4 1 6 I B
tune (SI
Fig 9 - Open loop responsesof the GCSC and TCSCw~thhgh levefsof
compensation,varymg from 80% to90% at BOO ms,andback to 80% at 13 s
I
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5. 5
' Fig,10-Equivalent 500 kV and765 LV Sy&m ofthe South of Brazil.
series compensation. Now the blocking angle is varied fiom
80% to 90% and back to 80%,in a pattern similar to that of
the previous simulation. The results are in Fig. 9. It is clear
that the TCSC is much slower thanthe GCSC at high levels of
compensation, i. e., with high currents af capacitor and reac-
tor. On the other hand, the open loop response of the GCSC
does not differ too much from that shown in Fig. 8, with low
level of series compensation.
B. Power Flow Scheduling in a Meshed Network
Zn order to show the capability of the GCSC to control
power flows, an ATP simulation of a meshed transmission
system was performed. The system, shown in Fig. 10, is an
equivalent ofpart of the 500 kV and 750 kV South-Southeast
Brazilian Network. Transmission lines 1 and 2, both in
500 kV, form a loop-flow: PIin Line 1 is 50% higher than the
P2 in Line 2. A GCSC, capable of compensate up to 80% of
seriesreactance, is operating with about halfof its capacity.
The GCSC increases its compensation to the maximum,
thus boosting the power flow through line 2 and establishing
the balancebetween the usageof both lines. Fig. 11showsthe
2000 I
I
j
. . ..I
F1400
E
5 l2O0
g 1000
::I , - ;400
0 3 0 4 0 5 0 6 0 7
time 6)
Fig I 1 -Power flows throughLines I and 2. aftercampensailonof Line 2
increases from 43%to 80% of the senesreactance
power flows in both lines before and &er the increment of
compensation by the GCSC. It is clear that the device could
quickly establish power flow equilibrium between both lines.
This test shows, in fact, that the GCSC can be used to control
power flow at different levels, which can be chosen by the
system operator. Fig. 12 shows the voltage in the GCSC be-
fore and after the step in the compensation of Line 2.
VI. HIGH POWER SELF-COMMLJTATEDVALVES: SOME
,"OLOGlCAL T"Ds
The design of a reliable high power self-commutated
switch is of paramount importance for the development and
manufacturing of a GCSC for an EHV transmission line. A
typical GCSC would he a multi-module equipment. Each
module might be designed to be a small GCSC cell, compris-
ing a relatively low voltage switch valve or even a single pair
of high power switches. Several GCSC cells could be con-
nected in series to form larger multi-module GCSC. The self-
commutated switch could be the GTO or, most likely, a more
modern semiconductor device, like the IGCT. The switch has
to be of the symmetrical type, in order to block reverse volt-
l_._._.l_l_-..
50
g o
-50
1 d
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6. ages.
Even with small GCSC cells, it may be necessary to con-
nect a number of semiconductor switches in series. The series
connection of GTO in hard-commutated converters to form
high power adjustable speed drive systems (ASD) has been a
technical challenge for years. This is not the case of the
GCSC, as it is a zero voltage switching equipment, what
makes the series connection of self-commutated switches
much easier [9]. Care must be taken with stray inductances
due to leads and cables that should be considered in the proj-
ect of snubber circuits. Another important issue to consider is
the Wdt limit of the semiconductor switches [lo].
VII. CONCLUSIONS
This paper presented a novel equipment for controllable se-
ries compensation of transmission lines: Gate Controlled Se-
ries Capacitor (GCSC). Some of the basic concepts behind the
equipment were reviewed. Emphasis was given to the fact that
the GCSC is the dual device of the Thyristor Controlled Re-
actor (TCR). This special characteristic not only helps to un-
derstand the GCSC principle of operation, but also makes the
analysis and possibly the equipment design rather easier. Due
to this duality, the authors believe that the GCSC may be a
more natural solution for series compensation than the TCSC,
and may be as widely adopted for series compensation as the
TCR is for shunt Compensation.
Comparison with the TCSC has shown that the GCSC is
more compact, with lesser passive components: it does not
need reactors and its capacitor bank is much smaller. Also, the
switches and capacitor currents are smaller in the GCSC. Be-
sides that, the semiconductor of the GCSC should be rated to a
slightly higher voltage than the SCR valves of the TCSC.
Some important issues regarding the development of high-
power valves are discussed. The main focus is the need of
development of a high-power valve comprising series con-
nected self-commutated switches capable of blocking reverse
voltage. Attention should also be given to the rate of rise of
current in the valves.
Simulation results demonstrate the operating principles of
the GCSC. Its open-loop dynamical response is faster than
that of the TCSC, specially at higher compensation levels.
Also, an example proved the capability of the GCSC to con-
trol power flow in transmission lines.
As a final remark, the authors believe that this new device
may be an excellent solution for transmission line controlled
series compensation. In the near future, the authors expect to
prove this technology by developing a full-scale GCSC pro-
totype to operate in an HV transmission system.
VIII. R E " C E . 3
[I] E. W.Kimbark "Improvementof System Stability by Switched Series
Capacitor,"JEW Trans. Power Apparatus undSystems, vol. 85, Febm-
ary 1966,pp. 180-188.
N. m o r a n i , L. Gyugyi UnderstandingFACIS: Concept.?and Tech-
n d o ~ofFlexible AC Trmsmmton SysIrms. EEEPress,2000.
T.J.E.Miller, Rractrve Power Control in Ekcfric Systems. New York
Wiley, 1982.
[2]
[31
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[4] A. A. Edris,Tower Electronic-BasedT&D ControllersAt Technologi-
cal Crossroad", EPRI Journal Onhe, August 2002 at
h t t p : / / w w w . e p r i . c o n ~ ~ ~ ~ ~ . ~ p ? d ~ ~ e a ~ & i d ~ 6 3 .
[5] G. G. Karady, T. H. Orbmyer. B. R F'ilvelait, D. Maratukulam, "Con-
tinuously Regulated Series Capacitor,"IEEE Trnns. Power Delrvery,
vol. 8,no.3, July 1993,pp. 1348-1354.
L. F. W.de S o w E.H. Watanabe, M Aredcs, %TO ControlledSeries
Capacitors:Multi-moddeand Multi-pulse Arrangements,"IEEE Tram.
Power Delivery,vol. 15, no.2. April2000. pp. 725-731.
L.F. W.de S o w E.H. Waianabe, M Aredcs. "A GTO Controlled
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Session, Session14,paper201, Paris,August 1998.
L. F. W.de So- E. H. Watanabe, I. E. R. Alves, L. A. S.Pilotto.
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ponents Rating",Proceedings of IEEE PES General Meeting, Toronto,
July 2003.
E. H.Wafanabe. M Aredes, L.P.W.de Sow M D. BelIar, "Series
C o d o n of Power Switches for Very High Power Appkicationsand
Zero VoltageSwitching."IEEE Trans.Power Elecironics,voL 15.no. 1,
January 2000, pp. 44-50.
[IO] M U N e j 4 T.H. Ortmeyer, "GTOTZlyristorControlled Series Capaci-
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April 1998.pp. 615-621.
[6]
{TJ
[8]
191
E.BIOGRAPHIES
Edson EIimkamWntannbe(M'76, SM'02) was born in Rio dc JaneiroState,
Brazil, on November07, 1952.He received the B.Sc. in Electronic Engineer-
ing and MSc. in ElectricalEngineering in 1975 and 1976, respectively,h m
the Federal University of Rio de Janeiro. In 1981 he got the D.Eng. degree
&om Tokyo Institute of Tecbnology,Japan. In 1981 he becamean Associate
Professor and in 1993 a Professor at COPPEiFederalUniversity of Rio de
Janeiro. where he teaches Power Eleclronics. His main fields ofinterests arc
convertersanalysis,mcdelingand desim activefilters andFACTS technolo-
gies.Dr. Watanabe is a member of the IEEJapan, The Brazilian Society for
AutomaticControlandTheBrazilianPowerElecbnics Society.
Luiz Felipe W ~ W Ide Son= (S'94, A'98, M W )was bom in Niterbi, Rio
de Janeiro State. B d . on Januaty IO. 1972. He received the B.Sc. degree
from Flumineme Federal University,Rio de Janeiro State, in 1994 a d the
U&.degree in Electrical Engineering from Federal University of Rio de
Janeiro in 1998.He is cwenlly w o r m towards his doctoratedegree at Fed-
eral University of Rio de Janeiro. From 1994 to 1996 he worked at Fumas
Centrais Eltirifas W A as a hydro power plant maintenance engineer. Since
1996 he works at CEPEL as a researchengineer.His main fields of interests
arepower quality andFACTS.
Fhbio Dominguesde Jesw was bomin Bnrretos,S b Paul0 State,B m l , on
May 12, 1971. He reoeived the E. S. degree in Electrical Engineeringfiom
FederalInstitutionof High Education of SHO Jo%Odel Rei, Brazil in 2000 and
the USc. degree at Elecbical Engineering Deprbmni in Federal University
of Juiz de Fora,Brazil in 2002. He is pursing his D.Sc.degree at Electrical
Engineering Department from COPPE-Federal University of Rio de Jnneim,
Bmil Hispresent research interestsincludethe high-power electronics,mdy-
sis andmni~olinFACTS.
JX.kAlvm Jr. (M'92F was h m in Juiz de Fora,B d , on November 30,
1963. He receivedthe B.Sc.,M.Sc. andD.Sc.degreesin electricalengineer-
ing, in 1986,1991 and 1999,respectivety. fiom the Federal Universityof Rio
de Janeiro.Since.1995hehasbeen wormat CEPEL, theBrazilianEleclrical
Energy ResearchCenter. Heis currentlyProjwtManager.Dr.Aives' research
interests are in the analysis of HVdc "ission systems, FACTS devices,
PowerElectroniccontrollers,DistributionSystemsand Metering.He became
a Member of the Institute of Electrical and Elecbnics Engineers (EEE) in
1992.He is currently a Member of the IEEE Power Engineering Society and
Sectetary of IEEERio deJaneiroSection.
Andd Bmnm "99) was born in Nova Igmqy Rio de Janeiro, Brazil, on
Junc 27, 1967. He received ttte B.Sc. and M.Sc. degrees in electrical enpi-
neering,in 1990 and 1994, respectivelyfiom the GamaFilho University and
from the Catholic University of Rio de Janeiro. From 1990 to 2003 he was
with =EL, initially as a graduafd student and then as a research engineer
with inkrest in the transienddynamic analysis of power systems includmg
HVdctransmission and FACTS devices.In 2004, Mr.Biancojoined Andrade
& Canellas Consulting, where he is the head of the elechical and energetic
studiesgroup.
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