Unified Power Flow Controller (UPFC) is one of the most intriguing and, potentially, the most versatile classes of Flexible AC Transmission Systems (FACTS) devices. The UPFC is a device which can control simultaneously tree parameters line impedance, voltage, phase angle and dynamic compensation of AC power system. In order to analyze its true effects on power systems, it is important to model its constraints, due to various ratings and operating limits. This paper reviews on the different models of UPFC used in recent years and gives sets of information for each model of the UPFC in AC transmission. Then the different models are compared and features of each model are examined.
Static Sustenance of Power System Stability Using FLC Based UPFC in SMIB Powe...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 Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Unified Power Quality Conditioner Model Based with Series and Shunt FiltersIAES-IJPEDS
With the increase of the complexion in the power distribution system, it is very possible that several kinds of power quality disturbances are happened in a power distribution system simultaneously.This paper proposes a unified power quality conditioner (UPQC) including a series and a shunt active power filter (APF) to compensate harmonics in both the distorted supply voltage and nonlinear load current. In the series APF control scheme, a proportional-integral (PI) controller, meanwhile a PI controller and are designed in the shunt APF control scheme to relieve harmonic currents produced by nonlinear loads. The DC voltage is maintained constant using Two degree of freedom proportional integral voltage controller (2DoFPI). The performance of the proposed UPQC is significantly improved compared to the conventional control strategy. The feasibility of the proposed UPQC control scheme is validated through the simulations.
IRJET- Enhancement of Power Flow Capability in Power System using UPFC- A RevieWIRJET Journal
This document reviews the use of a Unified Power Flow Controller (UPFC) to enhance power flow capability in power systems. The UPFC is a flexible AC transmission system (FACTS) device that can control both real and reactive power flows on a transmission line. It consists of two voltage source converters connected by a DC link: a static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC). The STATCOM controls reactive power and the DC link voltage, while the SSSC injects a controlled AC voltage in series with the transmission line to vary the transmission line impedance and power flow. Simulation results show that a UPFC installed on the IEEE 5 bus test system can control power flows and
International Journal of Engineering and Science Invention (IJESI) inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Performance and Analysis of Reactive Power Compensation by Unified Power Flow...ijeei-iaes
The Unified Power Flow Controller (UPFC) is the most versatile of the FACTS controllers envisaged so far. The main function of the UPFC is to control the flow of real and reactive power by injection of a voltage in series with the transmission line. Both the magnitude and the phase angle of the voltage can be varied independently. Real and Reactive power flow control can allow for power flow in prescribed routes, loading of transmission lines close to their thermal limits and can be utilized for improving transient and small signal stability of the power system. In this paper UPFC is incorporated in a SMIB (Single Machine Infinite Bus) system and the response of SMIB system has been recorded with and without UPFC, thereafter the comparison of both the output has been done. When no UPFC is installed, real and reactive power through the transmission line cannot be controlled. This paper presents control and performance of UPFC intended for installation on that transmission line to control power flow. Installing the UPFC makes it possible to control amount of active power flowing through the line. Simulations are carried out using MATLAB software to validate the performance of the UPFC.
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.
Power flow control in parallel transmission lines based on UPFCjournalBEEI
The power flow controlled in the electric power network is one of the main factors that affected the modern power systems development. The unified power flow controller (UPFC) is a FACTS powerful device that can control both active and reactive power flow of parallel transmission lines branches. In this paper, modelling and simulation of active and reactive power flow control in parallel transmission lines using UPFC with adaptive neuro-fuzzy logic is proposed. The mathematical model of UPFC in power flow is also proposed. The results show the ability of UPFC to control the flow of powers components "active and reactive power" in the controlled line and thus the overall power regulated between lines.
Enhancement for Power Quality in Distribution Side Using Custom Power DevicesIOSR Journals
1) The document discusses enhancing power quality in distribution systems using custom power devices like the Interline Unified Power Quality Conditioner (IUPQC).
2) It proposes using a Synchronous Reference Frame (SRF) control algorithm with a modified Phase Locked Loop (PLL) for generating gate signals to improve the IUPQC's performance under distorted voltage conditions.
3) The SRF method transforms voltage and current signals into rotating dq coordinates to extract fundamental frequency components, while the modified PLL improves determination of positive sequence system voltages for better filtering.
Static Sustenance of Power System Stability Using FLC Based UPFC in SMIB Powe...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 Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Unified Power Quality Conditioner Model Based with Series and Shunt FiltersIAES-IJPEDS
With the increase of the complexion in the power distribution system, it is very possible that several kinds of power quality disturbances are happened in a power distribution system simultaneously.This paper proposes a unified power quality conditioner (UPQC) including a series and a shunt active power filter (APF) to compensate harmonics in both the distorted supply voltage and nonlinear load current. In the series APF control scheme, a proportional-integral (PI) controller, meanwhile a PI controller and are designed in the shunt APF control scheme to relieve harmonic currents produced by nonlinear loads. The DC voltage is maintained constant using Two degree of freedom proportional integral voltage controller (2DoFPI). The performance of the proposed UPQC is significantly improved compared to the conventional control strategy. The feasibility of the proposed UPQC control scheme is validated through the simulations.
IRJET- Enhancement of Power Flow Capability in Power System using UPFC- A RevieWIRJET Journal
This document reviews the use of a Unified Power Flow Controller (UPFC) to enhance power flow capability in power systems. The UPFC is a flexible AC transmission system (FACTS) device that can control both real and reactive power flows on a transmission line. It consists of two voltage source converters connected by a DC link: a static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC). The STATCOM controls reactive power and the DC link voltage, while the SSSC injects a controlled AC voltage in series with the transmission line to vary the transmission line impedance and power flow. Simulation results show that a UPFC installed on the IEEE 5 bus test system can control power flows and
International Journal of Engineering and Science Invention (IJESI) inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Performance and Analysis of Reactive Power Compensation by Unified Power Flow...ijeei-iaes
The Unified Power Flow Controller (UPFC) is the most versatile of the FACTS controllers envisaged so far. The main function of the UPFC is to control the flow of real and reactive power by injection of a voltage in series with the transmission line. Both the magnitude and the phase angle of the voltage can be varied independently. Real and Reactive power flow control can allow for power flow in prescribed routes, loading of transmission lines close to their thermal limits and can be utilized for improving transient and small signal stability of the power system. In this paper UPFC is incorporated in a SMIB (Single Machine Infinite Bus) system and the response of SMIB system has been recorded with and without UPFC, thereafter the comparison of both the output has been done. When no UPFC is installed, real and reactive power through the transmission line cannot be controlled. This paper presents control and performance of UPFC intended for installation on that transmission line to control power flow. Installing the UPFC makes it possible to control amount of active power flowing through the line. Simulations are carried out using MATLAB software to validate the performance of the UPFC.
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.
Power flow control in parallel transmission lines based on UPFCjournalBEEI
The power flow controlled in the electric power network is one of the main factors that affected the modern power systems development. The unified power flow controller (UPFC) is a FACTS powerful device that can control both active and reactive power flow of parallel transmission lines branches. In this paper, modelling and simulation of active and reactive power flow control in parallel transmission lines using UPFC with adaptive neuro-fuzzy logic is proposed. The mathematical model of UPFC in power flow is also proposed. The results show the ability of UPFC to control the flow of powers components "active and reactive power" in the controlled line and thus the overall power regulated between lines.
Enhancement for Power Quality in Distribution Side Using Custom Power DevicesIOSR Journals
1) The document discusses enhancing power quality in distribution systems using custom power devices like the Interline Unified Power Quality Conditioner (IUPQC).
2) It proposes using a Synchronous Reference Frame (SRF) control algorithm with a modified Phase Locked Loop (PLL) for generating gate signals to improve the IUPQC's performance under distorted voltage conditions.
3) The SRF method transforms voltage and current signals into rotating dq coordinates to extract fundamental frequency components, while the modified PLL improves determination of positive sequence system voltages for better filtering.
A New Approach to Powerflow Management in Transmission System Using Interline...IJERA Editor
In this paper a new approach to power flow management in transmission system using interline Power Flow
Controller (IPFC) is proposed and model for IPFC is developed and simulate by MATLAB software. Interline
Power Flow Controller is a versatile device can be used to control power flows of a multi-line system or subnetworks
An Interline Power Flow Controller (IPFC) is a converter based FACTS controller for series
compensation with capability of controlling power flow among multi-lines within the same corridor of the
transmission line. It consists of two or more Voltage Source Converters (VSCs) with a common dc-link. Real
power can be transferred via the common dc-link between the VSCs and each VSC is capable of exchanging
reactive power with its own transmission system
This paper presents an analysis of virtual-flux direct power control (VFDPC) technique for the three-phase pulse width modulation (PWM) ac-dc converter. The proposed VFDPC is developed by assuming the grid voltage and converter line filters quantities are related to a virtual three-phase ac motor. The controller works with less number of sensors by eliminating the voltage sensors used for measuring the three-phase grid voltage. The grid virtual flux which is proportional to the grid voltage will be estimated from the information of converter switching states, line current, and dc-link output voltage. Several analyses are performed in order to study the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations. The proportional integral (PI) controller at the outer voltage control loop of VFDPC is tuned properly and the entire PWM ac-dc converter system is simulated using MATLAB/Simulink to ensure the dc output voltage follow the desired output voltage under steady state and dynamic conditions. Ac-dc converter utilizing the proposed VFDPC is able to generate three-phase input current waveforms that are almost sinusoidal with low harmonics contents which is less than 5% and near unity power factor (pf) operation.
This document summarizes a research article that proposes using a Unified Power Quality Compensator (UPQC) device to regulate voltage and mitigate fluctuations at a weak grid connection to a wind farm. The UPQC uses internal control strategies to regulate the voltage at the wind farm terminals using its series converter, and uses its shunt converter to filter wind farm power and prevent voltage fluctuations. The control strategy manages active and reactive power sharing between the series and shunt converters through a common DC link. Simulation results showed the UPQC approach effectively regulated voltage during load changes and rejected power fluctuations from tower shadow effects at the wind turbines.
Power Quality Improvement by SRF Based Control using D-STATCOMIRJET Journal
1) The document discusses using a D-STATCOM with synchronous reference frame (SRF) control strategy to improve power quality issues like poor voltage regulation, reactive power burden, and harmonics.
2) The SRF control strategy transforms load current signals into a rotating d-q frame for control purposes. It uses a phase-locked loop and proportional-integral controllers to generate gate pulses that control the D-STATCOM.
3) MATLAB simulations show the SRF control strategy effectively eliminates harmonics and reactive power compensation for both linear and non-linear loads, maintaining unity power factor and reducing harmonic content in source currents.
The work presented in this paper is devoted to the control of a photovoltaic system connected to grid by a three level diode clamed inverter. A control structure based on three parts: dc link voltage control, power injected control and current control is proposed. In this work, the random PWM strategy is used to generate control signals for the multilevel inverter used us an interface to connect photovoltaic generators to the grid. Numerical simulations are performed using MATLAB / Simulink software, the simulation results for the proposed system indicate the performances of the proposed control structure, minimization of harmonics by the random PWM strategy applied and injection to the grid more active power by the multilevel inverter structure.
This document summarizes a research paper that investigates using a Distributed Power Flow Controller (DPFC) to improve voltage stability in a fourteen bus power system during a line interruption. It describes simulating the fourteen bus system under normal operation, with an interrupted line and no DPFC, and with an interrupted line and DPFC. The results show that with DPFC, the voltage, real power, and reactive power at the affected bus are maintained at near normal levels during the line interruption. The DPFC is able to improve voltage stability and power quality during the contingency event.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document summarizes a research paper that presents a design for a Unified Power Quality Conditioner connected to a three-phase four-wire distribution system to mitigate various power quality issues like voltage sag/swell, harmonics, and neutral current under different load conditions. A new control strategy is proposed based on extending single-phase instantaneous active and reactive power theory to the three-phase system to compensate for current imbalance. Simulation results in MATLAB/Simulink validate the UPQC's ability to mitigate issues and maintain a balanced source current under both linear and non-linear, balanced and unbalanced load conditions.
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erpublication.org,
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Analysis and mitigation of unbalance due to load in distribution system by us...eSAT Journals
Abstract Distribution network losses can vary significantly depending on the load unbalance. Here, an analysis of distribution system losses is presented that considers load unbalance and the effect of explicitly represented neutral wire. A general power flow algorithm for three-phase four-wire radial distribution networks, based on the current summation backward-forward technique is applied. Loss analysis results obtained from three-phase four-wire medium and low voltage test feeders with unbalanced load scenarios are presented and discussed an active power filter is designed, simulated, implemented, and tested. It can work in different modes: active power filtering, power factor correction, and load unbalance compensation. It is based on a current controlled voltage-source inverter with fixed carrier PWM. The control algorithm generates the source reference currents based on the controlled DC link voltage. The dimensioning criteria of the inductive and capacitive power components are discussed. The implementation is validated with simulated and experimental results obtained in a 5 kVA prototype. Keywords: distribution networks, losses, load unbalance, power flow
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Evolve the Controller for Static Synchronous Series Compensator Based on Cont...IJPEDS-IAES
Real and Reactive power flow in an alternating current transmission line can be independently controlled by connecting, to the transmission line, a series- compensating voltage, which is variable in magnitude and phase angle. The Static Synchronous Series Compensator (SSSC), a solid-state voltage source inverter (VSC) coupled with a transformer, is connected in series with a transmission line. An SSSC injects an almost sinusoidal voltage, of variable magnitude, in series with a transmission line. This injected voltage is almost in quadrature with the line current, thereby emulating an inductive or a capacitive reactance in series with the transmission line. This emulated variable reactance, inserted by the injected voltage source, influences the electric power flow in the transmission line. In this report, an attempt is made to evolve the model of SSSC and VSC with preliminary studies for the controller design.
IRJET- A Placement Method of Fuzzy based UPFC to Enhance Voltage Stability Ma...IRJET Journal
This document presents a method for placing a fuzzy logic-based unified power flow controller (UPFC) in a power system network to enhance dynamic voltage stability. Voltage stability indices, including the LQP index and voltage collapse point indicators (VCPI), are used to determine the weakest transmission line under dynamic load variations. The UPFC's shunt and series converters are controlled using fuzzy logic and PI controllers, respectively. Simulations in PSCAD show that placing the fuzzy-based UPFC on the weakest line identified by the indices significantly improves voltage stability in IEEE 5-bus and 14-bus test systems.
Closed Loop Non Linear Control of Shunt Hybrid Power Filter for Harmonics Mit...IAES-IJPEDS
In recent years, the amount of non-linear loads has increased considerably since there were improvements in power electronic equipment (such as adjustable speed drives or converter ac-dc, ac-ac, dc-ac and dc-dc) in industrial sectors which cause deterioration of the quality of the electric power supply through distortion of supply voltage and supply current. This has led to improvement of many stringent needs regarding generation of harmonic current, which are found in IEEE519 and IEC61000 standards. This paper proposes a non-linear function based closed loop control strategy (without load current extraction) for three-phase Shunt Active Power Line Conditioner and LC passive filter to compensate harmonics, power factor improvement and enhance the dynamic performance of Shunt Hybrid Power Filter (SHPF). By using a PI controller the DC bus voltage of the Shunt Active Power Filter is maintained constant. Results obtained from simulation shows the performance of expected hybrid filter in transient and steady state operation . This indicates that the controller is able to compensate even under severe load current imbalances.
Close Loop Control of Induction Motor Using Z-Source InverterIJSRD
In this paper a new closed loop control of induction motor fed by a Z – source inverter based on the vector control or field oriented control strategy is presented. Induction motor is supplied by Z – source inverter, in the Z – source inverter the term Z denotes impedance which means a combination of L & C element which are cross connected. The Z-source inverter consists of a unique impedance network (or circuit) to couple the inverter main circuit to the power supply, hence providing great features that cannot be observed in the conventional voltage-source inverter and current-source inverters in which capacitor and inductor are used, respectively.In the field oriented control method or vector control method speed of the induction motor, torque & 3 phase stator current is given to the field oriented controller and gate pulses for the inverter is generated to obtain the desired operation of the induction motor.
A single rating inductor multilevel current source inverter with pwm strategieIAEME Publication
This document summarizes a research paper about a single-rating inductor multilevel current source inverter (MCSI) topology that uses phase-shifted carrier pulse width modulation (PSC-SPWM) and space vector modulation (SVM) control strategies. The proposed MCSI consists of identical modules where each module uses two balance inductors and six switches to determine different current levels at the output. PSC-SPWM is implemented using a state machine approach to balance the current in the inductors while minimizing switching frequency. Simulation results show the performance of a seven-level, three-module arrangement of the proposed MCSI topology.
Distribution Static Synchronous Compensator (DSTATCOM) is a shunt compensating device which is used
to improve current profile by exchanging of reactive power with unbalanced and nonlinear load. DSTATCOM is a
shunt compensating device used for power quality improvement in distribution systems. Relevant solutions are
applied for harmonics, fluctuation of voltage, voltage deviation, unbalance of three phase voltage and current and
frequency deviation. Different controlling schemes such as Phase Control Method (PCM), Fryze Power Theory
(FPT), Synchronous Reference Frame Theory (SRFT) and Instantaneous Reactive Power Theory (IRPT) are used
for reactive power compensation with the help of Voltage source Inverter (VSI). In this project we are going to
balance the source current using different control schemes. The results of different source currents are compared
with a different control schemes in terms of active and reactive power and in terms of Total Harmonic Distortion
(THD) for nonlinear load using Fryze Power Theory (FPT) and Instantaneous Reactive Power Theory (IRPT).
Reference currents are generated by the different control schemes have been dynamically traced in a hysteresis
current controller. The performance of DSTATCOM for different control schemes is validated for load balancing
and harmonic elimination by using simulation models in MATLAB/SIMULINK
Application of Backstepping to the Virtual Flux Direct Power Control of Five-...IJPEDS-IAES
This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.
Wind-Turbine Asynchronous Generator Synchronous Condenser with Excitation in ...IJMTST Journal
In this paper Standalone operation of a wind turbine generating system under fluctuating wind and variable load conditions is a difficult task. Moreover, high reactive power demand makes it more challenging due to the limitation of reactive capability of the wind generating system.The frequency is controlled by the Discrete Frequency Regulator block. This controller uses a standard three-phase Phase Locked Loop (PLL) system to measure the system frequency. The measured frequency is compared to the reference frequency to obtain the frequency error. This error is integrated to obtain the phase error. The phase error is then used by a Proportional-Differential (PD) controller to produce an output signal representing the required secondary load power. This signal is converted to an 8-bit digital signal controlling switching of the eight three-phase secondary loads. In order to minimize voltage disturbances, switching is performed at zero crossing of voltage.
1) The document proposes a new inverter design for Flexible AC Transmission System (FACTS) applications to improve efficiency.
2) The proposed inverter uses fewer switches than conventional cascaded H-bridge multilevel inverters, reducing switching losses. It produces 7 voltage levels using only 8 switches and 4 DC sources, whereas conventional designs require 12 switches and 3 DC sources.
3) Simulation results show that the proposed inverter produces voltage waveforms with lower harmonic content when used in a Static Synchronous Series Compensator (SSSC) FACTS controller, demonstrating its potential to improve FACTS system performance with reduced complexity.
Aircraft Electrical Power Generation & Distribution System Units Through an A...IJMTST Journal
This paper illustrates a generic Electrical Power Generation & Distribution System. The AC power frequency is variable and depends of the engine speed. The represents the generator mechanical drive and is modeled by a simple signal builder, which provides the mechanical speed of the engine shaft.The represents the power AC generator. It is composed of a modified version of the simplified synchronous machine. The mechanical input of the modified machine of 50 kW is the engine speed. The Generator Control Unit regulates the voltage of the generator to 200 volts line to line.The represents the Primary Distribution system. It is composed of three current and voltage sensors. There is also a 3-phase contactor controlled by the Generator Control Unit. Finally, a parasitic resistive load is required to avoid numerical oscillations. The section represents the secondary Power Distribution system. It is represented by 4 circuit breakers with adjustable current trip. The section represents the AC loads. There is a 4 kW Transformer and Rectifier Unit (which supplies 28 Vdc), a 12 kW induction machine (motor driving a pump), a 1 kW resistive load (lamps) and a 3 hp simplified (using an average value inverter) brushless DC drive (motor driving a ballscrew actuator)
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.
Load flow analysis with upfc under unsymmetrical fault conditionAlexander Decker
This document discusses load flow analysis with and without a Unified Power Flow Controller (UPFC) under different fault conditions in a six bus power system simulation model. The UPFC is a Flexible AC Transmission System (FACTS) device that can control parameters like voltage, impedance, and phase angle to control power flow. The study aims to improve transient stability of the six bus system by determining active and reactive power on load buses under different fault types both with and without the UPFC. The control scheme and operating principle of the UPFC are also explained.
A New Approach to Powerflow Management in Transmission System Using Interline...IJERA Editor
In this paper a new approach to power flow management in transmission system using interline Power Flow
Controller (IPFC) is proposed and model for IPFC is developed and simulate by MATLAB software. Interline
Power Flow Controller is a versatile device can be used to control power flows of a multi-line system or subnetworks
An Interline Power Flow Controller (IPFC) is a converter based FACTS controller for series
compensation with capability of controlling power flow among multi-lines within the same corridor of the
transmission line. It consists of two or more Voltage Source Converters (VSCs) with a common dc-link. Real
power can be transferred via the common dc-link between the VSCs and each VSC is capable of exchanging
reactive power with its own transmission system
This paper presents an analysis of virtual-flux direct power control (VFDPC) technique for the three-phase pulse width modulation (PWM) ac-dc converter. The proposed VFDPC is developed by assuming the grid voltage and converter line filters quantities are related to a virtual three-phase ac motor. The controller works with less number of sensors by eliminating the voltage sensors used for measuring the three-phase grid voltage. The grid virtual flux which is proportional to the grid voltage will be estimated from the information of converter switching states, line current, and dc-link output voltage. Several analyses are performed in order to study the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations. The proportional integral (PI) controller at the outer voltage control loop of VFDPC is tuned properly and the entire PWM ac-dc converter system is simulated using MATLAB/Simulink to ensure the dc output voltage follow the desired output voltage under steady state and dynamic conditions. Ac-dc converter utilizing the proposed VFDPC is able to generate three-phase input current waveforms that are almost sinusoidal with low harmonics contents which is less than 5% and near unity power factor (pf) operation.
This document summarizes a research article that proposes using a Unified Power Quality Compensator (UPQC) device to regulate voltage and mitigate fluctuations at a weak grid connection to a wind farm. The UPQC uses internal control strategies to regulate the voltage at the wind farm terminals using its series converter, and uses its shunt converter to filter wind farm power and prevent voltage fluctuations. The control strategy manages active and reactive power sharing between the series and shunt converters through a common DC link. Simulation results showed the UPQC approach effectively regulated voltage during load changes and rejected power fluctuations from tower shadow effects at the wind turbines.
Power Quality Improvement by SRF Based Control using D-STATCOMIRJET Journal
1) The document discusses using a D-STATCOM with synchronous reference frame (SRF) control strategy to improve power quality issues like poor voltage regulation, reactive power burden, and harmonics.
2) The SRF control strategy transforms load current signals into a rotating d-q frame for control purposes. It uses a phase-locked loop and proportional-integral controllers to generate gate pulses that control the D-STATCOM.
3) MATLAB simulations show the SRF control strategy effectively eliminates harmonics and reactive power compensation for both linear and non-linear loads, maintaining unity power factor and reducing harmonic content in source currents.
The work presented in this paper is devoted to the control of a photovoltaic system connected to grid by a three level diode clamed inverter. A control structure based on three parts: dc link voltage control, power injected control and current control is proposed. In this work, the random PWM strategy is used to generate control signals for the multilevel inverter used us an interface to connect photovoltaic generators to the grid. Numerical simulations are performed using MATLAB / Simulink software, the simulation results for the proposed system indicate the performances of the proposed control structure, minimization of harmonics by the random PWM strategy applied and injection to the grid more active power by the multilevel inverter structure.
This document summarizes a research paper that investigates using a Distributed Power Flow Controller (DPFC) to improve voltage stability in a fourteen bus power system during a line interruption. It describes simulating the fourteen bus system under normal operation, with an interrupted line and no DPFC, and with an interrupted line and DPFC. The results show that with DPFC, the voltage, real power, and reactive power at the affected bus are maintained at near normal levels during the line interruption. The DPFC is able to improve voltage stability and power quality during the contingency event.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document summarizes a research paper that presents a design for a Unified Power Quality Conditioner connected to a three-phase four-wire distribution system to mitigate various power quality issues like voltage sag/swell, harmonics, and neutral current under different load conditions. A new control strategy is proposed based on extending single-phase instantaneous active and reactive power theory to the three-phase system to compensate for current imbalance. Simulation results in MATLAB/Simulink validate the UPQC's ability to mitigate issues and maintain a balanced source current under both linear and non-linear, balanced and unbalanced load conditions.
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Analysis and mitigation of unbalance due to load in distribution system by us...eSAT Journals
Abstract Distribution network losses can vary significantly depending on the load unbalance. Here, an analysis of distribution system losses is presented that considers load unbalance and the effect of explicitly represented neutral wire. A general power flow algorithm for three-phase four-wire radial distribution networks, based on the current summation backward-forward technique is applied. Loss analysis results obtained from three-phase four-wire medium and low voltage test feeders with unbalanced load scenarios are presented and discussed an active power filter is designed, simulated, implemented, and tested. It can work in different modes: active power filtering, power factor correction, and load unbalance compensation. It is based on a current controlled voltage-source inverter with fixed carrier PWM. The control algorithm generates the source reference currents based on the controlled DC link voltage. The dimensioning criteria of the inductive and capacitive power components are discussed. The implementation is validated with simulated and experimental results obtained in a 5 kVA prototype. Keywords: distribution networks, losses, load unbalance, power flow
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Evolve the Controller for Static Synchronous Series Compensator Based on Cont...IJPEDS-IAES
Real and Reactive power flow in an alternating current transmission line can be independently controlled by connecting, to the transmission line, a series- compensating voltage, which is variable in magnitude and phase angle. The Static Synchronous Series Compensator (SSSC), a solid-state voltage source inverter (VSC) coupled with a transformer, is connected in series with a transmission line. An SSSC injects an almost sinusoidal voltage, of variable magnitude, in series with a transmission line. This injected voltage is almost in quadrature with the line current, thereby emulating an inductive or a capacitive reactance in series with the transmission line. This emulated variable reactance, inserted by the injected voltage source, influences the electric power flow in the transmission line. In this report, an attempt is made to evolve the model of SSSC and VSC with preliminary studies for the controller design.
IRJET- A Placement Method of Fuzzy based UPFC to Enhance Voltage Stability Ma...IRJET Journal
This document presents a method for placing a fuzzy logic-based unified power flow controller (UPFC) in a power system network to enhance dynamic voltage stability. Voltage stability indices, including the LQP index and voltage collapse point indicators (VCPI), are used to determine the weakest transmission line under dynamic load variations. The UPFC's shunt and series converters are controlled using fuzzy logic and PI controllers, respectively. Simulations in PSCAD show that placing the fuzzy-based UPFC on the weakest line identified by the indices significantly improves voltage stability in IEEE 5-bus and 14-bus test systems.
Closed Loop Non Linear Control of Shunt Hybrid Power Filter for Harmonics Mit...IAES-IJPEDS
In recent years, the amount of non-linear loads has increased considerably since there were improvements in power electronic equipment (such as adjustable speed drives or converter ac-dc, ac-ac, dc-ac and dc-dc) in industrial sectors which cause deterioration of the quality of the electric power supply through distortion of supply voltage and supply current. This has led to improvement of many stringent needs regarding generation of harmonic current, which are found in IEEE519 and IEC61000 standards. This paper proposes a non-linear function based closed loop control strategy (without load current extraction) for three-phase Shunt Active Power Line Conditioner and LC passive filter to compensate harmonics, power factor improvement and enhance the dynamic performance of Shunt Hybrid Power Filter (SHPF). By using a PI controller the DC bus voltage of the Shunt Active Power Filter is maintained constant. Results obtained from simulation shows the performance of expected hybrid filter in transient and steady state operation . This indicates that the controller is able to compensate even under severe load current imbalances.
Close Loop Control of Induction Motor Using Z-Source InverterIJSRD
In this paper a new closed loop control of induction motor fed by a Z – source inverter based on the vector control or field oriented control strategy is presented. Induction motor is supplied by Z – source inverter, in the Z – source inverter the term Z denotes impedance which means a combination of L & C element which are cross connected. The Z-source inverter consists of a unique impedance network (or circuit) to couple the inverter main circuit to the power supply, hence providing great features that cannot be observed in the conventional voltage-source inverter and current-source inverters in which capacitor and inductor are used, respectively.In the field oriented control method or vector control method speed of the induction motor, torque & 3 phase stator current is given to the field oriented controller and gate pulses for the inverter is generated to obtain the desired operation of the induction motor.
A single rating inductor multilevel current source inverter with pwm strategieIAEME Publication
This document summarizes a research paper about a single-rating inductor multilevel current source inverter (MCSI) topology that uses phase-shifted carrier pulse width modulation (PSC-SPWM) and space vector modulation (SVM) control strategies. The proposed MCSI consists of identical modules where each module uses two balance inductors and six switches to determine different current levels at the output. PSC-SPWM is implemented using a state machine approach to balance the current in the inductors while minimizing switching frequency. Simulation results show the performance of a seven-level, three-module arrangement of the proposed MCSI topology.
Distribution Static Synchronous Compensator (DSTATCOM) is a shunt compensating device which is used
to improve current profile by exchanging of reactive power with unbalanced and nonlinear load. DSTATCOM is a
shunt compensating device used for power quality improvement in distribution systems. Relevant solutions are
applied for harmonics, fluctuation of voltage, voltage deviation, unbalance of three phase voltage and current and
frequency deviation. Different controlling schemes such as Phase Control Method (PCM), Fryze Power Theory
(FPT), Synchronous Reference Frame Theory (SRFT) and Instantaneous Reactive Power Theory (IRPT) are used
for reactive power compensation with the help of Voltage source Inverter (VSI). In this project we are going to
balance the source current using different control schemes. The results of different source currents are compared
with a different control schemes in terms of active and reactive power and in terms of Total Harmonic Distortion
(THD) for nonlinear load using Fryze Power Theory (FPT) and Instantaneous Reactive Power Theory (IRPT).
Reference currents are generated by the different control schemes have been dynamically traced in a hysteresis
current controller. The performance of DSTATCOM for different control schemes is validated for load balancing
and harmonic elimination by using simulation models in MATLAB/SIMULINK
Application of Backstepping to the Virtual Flux Direct Power Control of Five-...IJPEDS-IAES
This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.
Wind-Turbine Asynchronous Generator Synchronous Condenser with Excitation in ...IJMTST Journal
In this paper Standalone operation of a wind turbine generating system under fluctuating wind and variable load conditions is a difficult task. Moreover, high reactive power demand makes it more challenging due to the limitation of reactive capability of the wind generating system.The frequency is controlled by the Discrete Frequency Regulator block. This controller uses a standard three-phase Phase Locked Loop (PLL) system to measure the system frequency. The measured frequency is compared to the reference frequency to obtain the frequency error. This error is integrated to obtain the phase error. The phase error is then used by a Proportional-Differential (PD) controller to produce an output signal representing the required secondary load power. This signal is converted to an 8-bit digital signal controlling switching of the eight three-phase secondary loads. In order to minimize voltage disturbances, switching is performed at zero crossing of voltage.
1) The document proposes a new inverter design for Flexible AC Transmission System (FACTS) applications to improve efficiency.
2) The proposed inverter uses fewer switches than conventional cascaded H-bridge multilevel inverters, reducing switching losses. It produces 7 voltage levels using only 8 switches and 4 DC sources, whereas conventional designs require 12 switches and 3 DC sources.
3) Simulation results show that the proposed inverter produces voltage waveforms with lower harmonic content when used in a Static Synchronous Series Compensator (SSSC) FACTS controller, demonstrating its potential to improve FACTS system performance with reduced complexity.
Aircraft Electrical Power Generation & Distribution System Units Through an A...IJMTST Journal
This paper illustrates a generic Electrical Power Generation & Distribution System. The AC power frequency is variable and depends of the engine speed. The represents the generator mechanical drive and is modeled by a simple signal builder, which provides the mechanical speed of the engine shaft.The represents the power AC generator. It is composed of a modified version of the simplified synchronous machine. The mechanical input of the modified machine of 50 kW is the engine speed. The Generator Control Unit regulates the voltage of the generator to 200 volts line to line.The represents the Primary Distribution system. It is composed of three current and voltage sensors. There is also a 3-phase contactor controlled by the Generator Control Unit. Finally, a parasitic resistive load is required to avoid numerical oscillations. The section represents the secondary Power Distribution system. It is represented by 4 circuit breakers with adjustable current trip. The section represents the AC loads. There is a 4 kW Transformer and Rectifier Unit (which supplies 28 Vdc), a 12 kW induction machine (motor driving a pump), a 1 kW resistive load (lamps) and a 3 hp simplified (using an average value inverter) brushless DC drive (motor driving a ballscrew actuator)
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Load flow analysis with upfc under unsymmetrical fault conditionAlexander Decker
This document discusses load flow analysis with and without a Unified Power Flow Controller (UPFC) under different fault conditions in a six bus power system simulation model. The UPFC is a Flexible AC Transmission System (FACTS) device that can control parameters like voltage, impedance, and phase angle to control power flow. The study aims to improve transient stability of the six bus system by determining active and reactive power on load buses under different fault types both with and without the UPFC. The control scheme and operating principle of the UPFC are also explained.
POWER STABILITY ANALYSIS OF A TRANSMISSION SYSTEM WITH A UNIFIED POWER FLOW C...IJITE
The unified power quality conditioner is the equipment used for regulated voltage distortion and voltage
unbalance in a power system. UPFC can enhance the power to flow through the transmission system by
controlling the power flow and voltage stability of the transmission line within their limits. This paper
presents a control scheme and Theoretical derivation of the unified power flow conditioner and the
simulation results are compared and contrasted in detail. UPFC is a combination of shunt Active and
series active power filters. UPFC contains a DC link capacitor in a single-phase voltage source inverter
with two back to back connected, three-phase three-wire and three-phase four-wire are arranged. The
fundamental target of this work is to determine the causes and impacts of power quality problems,
specifically voltage sag, voltage swell, power factor, and Total Harmonics Distortion (THD) and enhance
the power quality of a transmission system by UPFC based Transformative Intrinsic Algorithm (TIA). The
Simulation of the proposed method is developed by Mat lab Simulink software, and the simulation result
shows, the proposed method gives better solutions to control the power imbalance in the distribution
system with its cost-effectiveness.
Power System Stability Enhancement Using Static Synchronous Series Compensato...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 Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
In recent years, studies have been investigated the effectiveness of UPFC and TCSC in increasing power transfer capability. However, the effectiveness of these FACTS devices in increasing power transfer capability when the load is non-linear has not been established in a comparative study yet. This paper will explore the steady-state performance of the UPFC and TCSC as impedance compensation models. The effectiveness of both FACTS devices are investigated when they are installed in multi-machine systems with different non-linear load models. Simulation results demonstrate that, upon installing UPFC, more active and reactive powers are received at the sending end bus for different types of non-linear load models. In addition, both active and reactive powers are more sensitive in changing the modulation index of the converters. Furthermore, both the active and reactive powers are less sensitive to the non-linearity of the load model type. However, active and reactive powers in case of installing TCSC are only sensitive in changing the firing angle (α) when it is between 90º to 110º. Therefore, results from this study clearly encourage the effectiveness of UPFC in comparison to TSCS in terms of increasing power transfer capability applied to non-linear load models.
Novel Direct Switching Power Control Method of UPFC by Using Matrix Converte...IJMER
This paper presents a direct Switching power control for three-phase matrix converters
operating as unified power flow controllers (UPFCs). Matrix converters (MCs) allow the direct ac/ac
power conversion without dc energy storage links; therefore, the MC-based UPFC (MC-UPFC) has
reduced volume and cost, reduced capacitor power losses, together with higher reliability. Theoretical
principles of direct Switching power control based on sliding mode control techniques are established
for an MC-UPFC dynamic model including the input filter. As a result, line active and reactive power,
together with ac supply reactive power, can be directly controlled by selecting an appropriate matrix
converter switching state guaranteeing good steady-state and dynamic responses. Experimental results
of DSPC controllers for MC-UPFC show decoupled active and reactive power control, zero steady-state
tracking error, and fast response times. Compared to an MC-UPFC using active and reactive power
linear controllers based on a modified Venturing high-frequency PWM modulator, the experimental
results of the advanced DSPC-MC guarantee faster responses without overshoot and no steady state
error, presenting no cross-coupling in dynamic and steady-state responses
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
This document describes simulations carried out on Distributed Power-Flow Controller (DPFC) technology. Key points:
- DPFC is derived from Unified Power Flow Controller (UPFC) but eliminates the common DC link between shunt and series converters. Active power is exchanged through the transmission line using third-harmonic frequency components.
- DPFC has advantages over UPFC of lower cost due to lower component ratings/isolation for series converter, and higher reliability due to redundancy of series converters.
- Detailed simulations were performed on a two-machine system to illustrate DPFC's control features and ability to increase power transfer capability and improve system reliability compared to conventional systems. Laboratory tests validated the DPFC operating principle and
Transient Stability of Power System using Facts Device-UPFCijsrd.com
This paper is based on Occurrence of a fault in a power system causes transients. To stabilize the system, The Flexible Alternating Current Transmission (FACTS) devices such as UPFC are becoming important in suppressing power system oscillations and improving system damping. The UPFC is a solid-state device, which can be used to control the active and reactive power.. By using a UPFC the oscillation introduced by the faults, the rotor angle and speed deviations can be damped out quickly than a system without a UPFC. The effectiveness of UPFC in suppressing power system oscillation is investigated by analyzing their oscillation in rotor angle and change in speed occurred in the two machine system considered in this work. A proportional integral (PI) controller has been employed for the UPFC. It is also shown that a UPFC can control independently the real and reactive power flow in a transmission line. A MATLAB simulation has been carried out to demonstrate the performance of the UPFC in achieving transient stability of the two-machine five-bus system.
The document discusses reactive power compensation using a Unified Power Flow Controller (UPFC). It begins with an introduction to Flexible AC Transmission Systems (FACTS) and defines a UPFC. It then discusses literature on FACTS controllers, the basic types of FACTS controllers including series and shunt configurations, and the merits and demerits of FACTS devices. The document focuses on the UPFC, describing its introduction, configuration, working, and its ability to control active and reactive power flow. It analyzes and compares the performance and applications of the UPFC to other FACTS controllers.
Power Quality Improvement And Mitigation Of Voltage Sag And Current Swell Usi...IJERA Editor
Modern power utilities have to respond to a number of challenges such as growth of electricity demand specially in non-linear loads in power grids, consequently, That higher power quality should be considered. In this paper, DPFC which is similar to unified power flow controller (UPFC) in structure, which is used to mitigate the voltage sag and swell as a power quality issue. Unlike UPFC, the common dc-link in DPFC, between the shunt and series converter devices should be eliminated and three-phase series converter is divided to several single-phase series distributed converters through the power transmission line. And also to detect the voltage sags and find out the three single-phase reference voltages of DPFC, the synchronous reference frame method is proposed. Application of DPFC in power quality enhancement is simulated in Mat lab/Simulink environment which show the effectiveness of the proposed structure
This document discusses a proposed method for improving power quality using a distributed power flow controller (DPFC). The DPFC is similar in structure to a unified power flow controller but eliminates the common DC link between converters. It uses a single shunt converter and multiple independent series converters connected along the transmission line. The DPFC is able to control transmission line parameters like impedance, angle, and voltage. It can mitigate issues like voltage sags and current swells. Simulation results using Matlab/Simulink show the DPFC effectively improves power quality by reducing sags, swells, and harmonics when a three-phase fault is applied to the system.
This document summarizes a research paper that proposes a direct power control (DPC) method for controlling a unified power flow controller (UPFC) that uses a matrix converter. Some key points:
1. A DPC technique is developed using sliding mode control principles to directly control the active and reactive line power flows of a UPFC that uses a matrix converter, without requiring DC energy storage components.
2. The DPC selects appropriate switching states of the matrix converter in real-time to control the active and reactive power errors based on voltage and current measurements.
3. Simulation and experimental results show the DPC provides decoupled control of active and reactive power with zero steady-state error and fast dynamic
An Adaptive Neuro-Fuzzy Inference Distributed Power Flow Controller (DPFC) in...IAES-IJPEDS
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Simulation Of Interline Power Flow Controller in Power Transmission Systemijsrd.com
The interline power flow controller (IPFC) is one of the latest generation flexible AC transmission systems (FACTS) controller used to control power flows of multiple transmission lines. The IPFC is the multifunction device, such as power flow control, voltage control, oscillation damping. This paper presents an overview and study and mathematical model of Interline Power Flow Control. The simulations of a simple power system of 500kV/230kV in MATLAB and simulation results are carried out on it. The results without and with IPFC are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model.
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Control of Active And reactive power flow in transmission line and power Osci...AM Publications
the continuous demand in electric power system network has caused the system to be heavily loaded
leading to voltage instability. This paper describe the active approach to series line compensation, in which static
voltage sourced converter, is used to provide controllable series compensation. This compensator is called as Static
synchronous series compensator (SSSC). It injects the compensating voltage in phase quadrature with line current, it
can emulate as inductive or capacitive reactance so as to influence the power flow in the line. With DC power supply it
can also compensate the voltage drop across the resistive component of the line impedance. In addition, the series
reactive compensation can greatly increase the power oscillation damping.
Simulations have been done in MATLAB SIMULINK. Simulation results obtained for selected bus-2 in two machine
power system. From the result we can investigate the effect of this device in controlling active and reactive power as
well as damping power system oscillations in transient mode.
- The document describes a unified power flow controller (UPFC) which consists of two voltage source converters connected respectively in series and shunt with a transmission line, with a common DC link.
- It proposes modeling the UPFC using a discrete simulator in MATLAB with 12-pulse converters to reduce voltage harmonics, and controlling the series and shunt converters separately while coordinating them.
- Simulation results showed the UPFC model reflected static and dynamic characteristics, and harmonics analysis was performed on the output during different system conditions including faults.
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Similar to Review of the UPFC Different Models in Recent Years (20)
Inter-Area Oscillation Damping using an STATCOM Based Hybrid Shunt Compensati...IJPEDS-IAES
FACTS devices are one of the latest technologies which have been used to
improve power system dynamic and stability during recent years. However,
widespread adoption of this technology has been hampered by high cost
and reliability concerns. In this paper an economical phase imbalanced shunt
reactive compensation concept has been introduced and its ability for power
system dynamic enhancement and inter-area oscillation damping are
investigated. A hybrid phase imbalanced scheme is a shunt capacitive
compensation scheme, where two phases are compensated by fixed shunt
capacitor (C) and the third phase is compensated by a Static Synchronous
Compensator (STATCOM) in shunt with a fixed capacitor (CC). The power
system dynamic stability enhancement would be achieved by adding
a conventional Wide Area Damping Controller (WADC) to the main control
loop of the single phase STATCOM. Two different control methodologies
are proposed: a non-optimized conventional damping controller
and a conventional damping controller with optomised parameters that are
added to the main control loop of the unbalanced compensator in order to
damp the inter area oscillations. The proposed arrangement would, certainly,
be economically attractive when compared with a full three-phase
STATCOM. The proposed scheme is prosperously applied in a 13-bus
six-machine test system and various case studies are conducted to
demonstrate its ability in damping inter-area oscillations and power system
dynamic enhancement.
Fuzzy Gain-Scheduling Proportional–Integral Control for Improving the Speed B...IJPEDS-IAES
In this article, we have set up a vector control law of induction machine
where we tried different type of speed controllers. Our control strategy is of
type Field Orientated Control (FOC). In this structure we designed a Fuzzy
Gain-Scheduling Proportional–Integral (Pi) controller to obtain best result
regarding the speed of induction machine. At the beginning we designed a Pi
controller with fixed parameters. We came up to these parameters by
identifying the transfer function of this controller to that of Broïda (second
order transfer function). Then we designed a fuzzy logic (FL) controller.
Based on simulation results, we highlight the performances of each
controller. To improve the speed behaviour of the induction machine, we
have designend a controller called “Fuzzy Gain-Scheduling Proportional–
Integral controller” (FGS-PI controller) which inherited the pros of the
aforementioned controllers. The simulation result of this controller will
strengthen its performances.
Advance Technology in Application of Four Leg Inverters to UPQCIJPEDS-IAES
This article presents a novel application of four leg inverter with
conventional Sinusoidal Pulse Width Modulation (SPWM) Scheme to
Unified Power Quality Conditioner (UPQC). The Power Quality problem
became burning issues since the starting of high voltage AC transmission
system. Hence, in this article it has been discussed to mitigate the PQ issues
in high voltage AC systems through a three phase Unified Power Quality
Conditioner (UPQC) under various conditions, such as harmonic mitigation
scheme, non linear loads, sag and swell conditions as well. Also, it proposes
to control harmoincs with various artificial intelligent techniques. Thus
application of these control technique such as Neural Networks (ANN)
Fuzzy Logic makes the system performance in par with the standards
and also compared with existing system. The simulation results based on
MATLAB/Simulink are discussed in detail to support the concept developed
in the paper.
Modified SVPWM Algorithm for 3-Level Inverter Fed DTC Induction Motor DriveIJPEDS-IAES
In this paper, a modified space vector pulse width modulation (MSVPWM)
algorithm is developed for 3-level inverter fed direct torque controlled
induction motor drive (DTC-IMD). MSVPWM algorithm simplifies
conventional space vector pulse width modulation (CSVPWM) algorithm for
multilevel inverter (MLI), whose complexity lies in sector/subsector/subsubsector
identification; which will commensurate with number of levels. In
the proposed algorithm sectors are identified as in two level inverter
and subsectors/sub-subsectors are identified by shifting the original reference
vector to sector 1 (S1). This is valid due to the fact that a three level space
vector plane is a composition of six two level space planes, and are
symmetrical with reference to six pivot states. Switching state/sequence
selection is also very important while dealing with SVPWM strategy for
MLI. In the proposed algorithm out of 27 available switching states apt
switching state is selected based on sector and subsector number, such that
voltage ripple is considerably less. To validate the proposed algorithm, it is
tested on a three level neutral point clamped (NPC) inverter fed DTC-IMD.
The performance of the MSVPWM algorithm is analyzed by comparing no
load stator current ripple of the three level DTC-IMD with two level
DTC-IMD. Significant reduction in steady state torque and flux ripple is
observed. Hence, reduced acoustic noise is a distinctive facet of the proposed
method.
Modelling of a 3-Phase Induction Motor under Open-Phase Fault Using Matlab/Si...IJPEDS-IAES
The d-q model of Induction Motors (IMs) has been effectively used as an
efficient method to analyze the performance of the induction machines. This
study presents a step by step Matlab/Simulink implementation
of a star-connected 3-phase IM under open-phase fault (faulty 3-phase IM)
using d-q model. The presented technique in this paper can be simply
implemented in one block and can be made available for control purposes.
The simulated results provide to show the behavior of the star-connected 3-phase IM under open-phase fault condition.
Performance Characteristics of Induction Motor with FielIJPEDS-IAES
With development of power electronics and control Theories, the AC motor
control becomes easier. So the AC motors are used instead of the DC motor
in the drive applications. With this development, a several methods of control
are invented. The field oriented control and direct torque control are from the
best methods to control the drive systems. This paper is compared between
the field oriented control and direct torque control to show the advantages
and disadvantages of these methods of controls. This study discussed the
effects of these methods of control on the total harmonic distortion of the
current and torque ripples. This occurs through study the performance
characteristics of the AC motor. The motor used in this study is an induction
motor. This study is simulated through the MATLAB program.
A Novel Modified Turn-on Angle Control Scheme for Torque- Ripple Reduction in...IJPEDS-IAES
In recent years, Switched Reluctance Motors (SRM) have been dramatically
considered with both researchers and industries. SRMs not only have a
simple and reliable structure, but also have low cost production process.
However, discrete torque production of SRM along with intensive magnetic
saturation in stator and rotor cores are the major drawbacks of utilizing in
variety of industrial applications and also causes the inappropriate torque
ripples. In this paper, a modified logical-rule-based Torque Sharing Function
(TSF) method is proposed considering turn-on angle control. The optimized
turn-on angle for conducting each phase is achieved by estimating the
inductance curve in the vicinity of unaligned position and based on an
analytical solution for each phase voltage equation. Simulation results on a
four-phase switched reluctance motor and comparison with the conventional
methods validates the effectiveness of the proposed method.
Modeling and Simulation of Induction Motor based on Finite Element AnalysisIJPEDS-IAES
This paper presents the development of a co-simulation platform of induction
motor (IM). For the simulation, a coupled model is introduced which
contains the control, the power electronics and also the induction machine.
Each of these components is simulated in different software environments.
So, this study provides an advanced modeling and simulation tools for IM
which integrate all the components into one common simulation platform
environment. In this work, the IM is created using Ansys-Maxwell based on
Finite Element Analysis (FEA), whereas the power electronic converter is
developed in Ansys-Simplorer and the control scheme is build in MATLABSimulink
environment. Such structure can be useful for accurate design
and allows coupling analysis for more realistic simulation. This platform is
exploited to analyze the system models with faults caused by failures of
different drive’s components. Here, two studies cases are presented: the first
is the effects of a faulty device of the PWM inverter, and the second case is
the influence of the short circuit of two stator phases. In order to study the
performance of the control drive of the IM under fault conditions,
a co-simulation of the global dynamic model has been proposed to analyze
the IM behavior and control drives. In this work, the co-simulation has been
performed; furthermore the simulation results of scalar control allowed
verifying the precision of the proposed FEM platform.
Comparative Performance Study for Closed Loop Operation of an Adjustable Spee...IJPEDS-IAES
In this paper an extensive comparative study is carried out between PI
and PID controlled closed loop model of an adjustable speed Permanent
Magnet Synchronous Motor (PMSM) drive. The incorporation of Sinusoidal
Pulse Width Modulation (SPWM) strategy establishes near sinusoidal
armature phase currents and comparatively less torque ripples without
sacrificing torque/weight ratio. In this closed loop model of PMSM drive, the
information about reference speed is provided to a speed controller, to ensure
that actual drive speed tracks the reference speed with ideally zero steady
state speed error. The entire model of PMSM closed loop drive is divided
into two loops, inner loop current and outer loop speed. By taking the
different combinations of two classical controllers (PI & PID) related with
two loop control structure, different approximations are carried out. Hence a
typical comparative study is introduced to familiar with the different
performance indices of the system corresponding to time domain and
frequency domain specifications. Therefore overall performance of closed
loop PMSM drive is tested and effectiveness of controllers will be
determined for different combinations.
Novel Discrete Components Based Speed Controller for Induction MotorIJPEDS-IAES
This paper presents an electronic design based on general purpose discrete
components for speed control of a single phase induction motor drive. The
MOSFETs inverter switching is controlled using Sampled Sinusoidal Pulse
Width Modulation (SPWM) techniques with V/F method based on Voltage
Controlled Oscillator (VCO). The load power is also controlled by a novel
design to produce a suitable SPWM pulse. The proposed electronic system
has ability to control the output frequency with flexible setting of lower limit
to less than 1 Hz and to higher frequency limits to 55 Hz. Moreover, the
proposed controller able to control the value of load voltage to frequency
ratio, which plays a major parameter in the function of IM speed control.
Furthermore, the designed system is characterized by easy manufacturing
and maintenance, high speed response, low cost, and does not need to
program steps as compared to other systems based on Microcontroller
and digital signal processor (DSP) units. The complete proposed electronic
design is made by the software of NI Multisim version 11.0 and all the
internal sub-designs are shown in this paper. Simulation results show the
effectiveness of electronic design for a promising of a high performance IM
PWM drive.
Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-Phase Op...IJPEDS-IAES
This paper introduces a sensorless-speed-controlled PMSM motor fed by a
four-leg inverter in case of a single phase open circuit fault regardless in
which phase is the fault. To minimize the system performance degradation
due to a single phase open circuit fault, a fault tolerant control strategy that
includes taking appropriate actions to control the two remaining healthy
currents is used in addition to use the fourth leg of the inverter. Tracking the
saliency is done through measuring the dynamic current responses of the
healthy phases of the PMSM motor due the IGBT switching actions using the
fundamental PWM method without introducing any modification to the
operation of the fourth leg of the inverter. Simulation results are provided to
verify the effectiveness of the proposed strategy for sensorless controlling of
a PMSM motor driven by a fault-tolerant four-phase inverter over a wide
speed ranges under the case of a single phase open circuit.
Improved Stator Flux Estimation for Direct Torque Control of Induction Motor ...IJPEDS-IAES
Stator flux estimation using voltage model is basically the integration of the
induced stator back electromotive force (emf) signal. In practical
implementation the pure integration is replaced by a low pass filter to avoid
the DC drift and saturation problems at the integrator output because of the
initial condition error and the inevitable DC components in the back emf
signal. However, the low pass filter introduces errors in the estimated stator
flux which are significant at frequencies near or lower than the cutoff
frequency. Also the DC components in the back emf signal are amplified at
the low pass filter output by a factor equals to . Therefore, different
integration algorithms have been proposed to improve the stator flux
estimation at steady state and transient conditions. In this paper a new
algorithm for stator flux estimation is proposed for direct torque control
(DTC) of induction motor drives. The proposed algorithm is composed of a
second order high pass filter and an integrator which can effectively
eliminates the effect of the error initial condition and the DC components.
The amplitude and phase errors compensation algorithm is selected such that
the steady state frequency response amplitude and phase angle are equivalent
to that of the pure integrator and the multiplication and division by stator
frequency are avoided. Also the cutoff frequency selection is improved; even
small value can filter out the DC components in the back emf signal. The
simulation results show the improved performance of the induction motor
direct torque control drive with the proposed stator flux estimation algorithm.
The simulation results are verified by the experimental results.
Minimization of Starting Energy Loss of Three Phase Induction Motors Based on...IJPEDS-IAES
The purpose of this paper is to minimize energy losses consumed by three
phase induction motors during starting with wide range of load torque from
no load to full load. This will limit the temperature rise and allows for more
numbers of starting during a definite time. Starting energy losses
minimization is achieved by controlling the rate of increasing voltage
and frequency to start induction motor under certain load torque within a
definite starting time. Optimal voltage and frequency are obtained by particle
swarm optimization (PSO) tool according to load torque. Then, outputs of the
PSO are used to design a neuro-fuzzy controller to control the output voltage
and frequency of the inverter during starting for each load torque. The
starting characteristics using proposed method are compared to that of direct
on line and V/F methods. A complete model of the system is developed using
SIMULINK/MATLAB.
Hardware Implementation of Solar Based Boost to SEPIC Converter Fed Nine Leve...IJPEDS-IAES
Multi level inverters are widely used in high power applications because of
low harmonic distortion. This paper deals with the simulation
and implementation of PV based boost to SEPIC converter with multilevel
inverter. The output of PV system is stepped up using boost to sepic
converter and it is converted into AC using a multilevel inverter.
The simulation and experimental results with the R load is presented in this
paper. The FFT analysis is done and the THD values are compared. Boost to
SEPIC converter is proposed to step up the voltage to the required value. The
experimental results are compared with the simulation results. The results
indicate that nine level inverter system has better performance than seven
level inverter system.
Transformer Less Voltage Quadrupler Based DC-DC Converter with Coupled Induct...IJPEDS-IAES
In this paper a voltage quadrupler dc-dc converter with coupled inductor
and π filter is presented. The use of the coupled inductor reduces the high
leakage inductance which is present in a transformer enabled converter.
The output ripples in the converter is reduced by providing a π filter.
The interleaved voltage quadrupler is used in this system in order to boost the
output voltage. The voltage multiplier improves the output voltage gain.
The main advantage of this system is more voltage gain when compared with
the transformer eneabled circuit and the overall efficiency of the system is
improved. The circuit is simple to control. As a final point of this research,
the simulation and the hardware investigational results are presented to
demonstrate the effectiveness of this proposed converter.
IRAMY Inverter Control for Solar Electric VehicleIJPEDS-IAES
Solar Electric Vehicles (SEV) are considered the future vehicles to solve the issues of air pollution, global warming, and the rapid decreases of the petroleum resources facing the current transportation technology. However, SEV are still facing important technical obstacles to overcome. They include batteries energy storage capacity, charging times, efficiency of the solar panels and electrical propulsion systems. Solving any of those problems and electric vehicles will compete-complement the internal combustion engines vehicles. In the present work, we propose an electrical propulsion system based on three phase induction motor in order to obtain the desired speed and torque with less power loss. Because of the need to lightweight nature, small volume, low cost, less maintenance and high efficiency system, a three phase squirrel cage induction motor (IM) is selected in the electrical propulsion system. The IM is fed from three phase inverter operated by a constant V/F control method and Space Vector Pulse Width Modulation (SVPWM) algorithm. The proposed control strategy has been implemented on the texas instruments TM320F2812 Digital Signal Processor (DSP) to generate SVPWM signal needed to trigger the gates of IGBT based inverter. The inverter used in this work is a three phase inverter IRAMY20UP60B type. The experimental results show the ability of the proposed control strategy to generate a three-phase sine wave signal with desired frequency. The proposed control strategy is experimented on a locally manufactured EV prototype. The results show that the EV prototype can be propelled to speed up to 60km/h under different road conditions.
Design and Implementation of Single Phase AC-DC Buck-Boost Converter for Powe...IJPEDS-IAES
This paper discusses the Power Factor Correction (PFC) for single phase AC-DC Buck-Boost Converter (BBC) operated in Continuous Conduction Mode (CCM) using inductor average current mode control. The proposed control technique employs Proportional-Integral (PI) controller in the outer voltage loop and the Inductor Average Current Mode Control (IACMC) in the inner current loop for PFC BBC. The IACMC has advantages such as robustness when there are large variations in line voltage and output load. The PI controller is developed by using state space average model of BBC. The simulation of the proposed system with its control circuit is implemented in MatLab/Simulink. The simulation results show a nearly unity power factor can be attained and there is almost no change in power factor when the line frequency is at various ranges. Experimental results are provided to show its validity and feasibility.
Improvement of Wind farm with PMSG using STATCOMIJPEDS-IAES
This paper studies about the dynamic performance of the Permanent Magnet Synchronous Generator with Static Synchronous Compensator (STATCOM) for Wind farm integration. A whole dynamic model of wind energy conversion system (WECS) with PMSG and STATCOM are established in a MATLAB environment. With this model the dynamic behaviour of the generator and the overall system has been studied to determine the performance of them with and without STATCOM. Final results portrays that the WECS based PMSG with STATCOM improves the transient response of the wind farm when the system is in fault.
Modeling and Control of a Doubly-Fed Induction Generator for Wind Turbine-Gen...IJPEDS-IAES
This paper presents a vector control direct (FOC) of double fed induction generator intended to control the generated stator powers. This device is intended to be implemented in a variable-speed wind-energy conversion system connected to the grid. In order to control the active and reactive power exchanged between the machine stator and the grid, the rotor is fed by a bi-directional converter. The DFIG is controlled by standard relay controllers. Details of the control strategy and system simulation were performed using Simulink and the results are presented in this here to show the effectiveness of the proposed control strategy.
A Review on Design and Development of high Reliable Hybrid Energy Systems wit...IJPEDS-IAES
Hybrid Energy system is a combination of two or more different types of energy resources. Now a day this hybrid energy system plays key role in various remote area power applications. Hybrid energy system is more reliable than single energy system. This paper deals with high reliable hybrid energy system with solar, wind and micro hydro resources. The proposed hybrid system cable of multi mode operation and high reliable due to non communicated based controllers (Droop Characteristic Control) are used for optimal power sharing. Size of battery can be reduced because hydro used as back up source and Maximum power point Tracking also applied to solar and wind energy systems.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
A high-Speed Communication System is based on the Design of a Bi-NoC Router, ...DharmaBanothu
The Network on Chip (NoC) has emerged as an effective
solution for intercommunication infrastructure within System on
Chip (SoC) designs, overcoming the limitations of traditional
methods that face significant bottlenecks. However, the complexity
of NoC design presents numerous challenges related to
performance metrics such as scalability, latency, power
consumption, and signal integrity. This project addresses the
issues within the router's memory unit and proposes an enhanced
memory structure. To achieve efficient data transfer, FIFO buffers
are implemented in distributed RAM and virtual channels for
FPGA-based NoC. The project introduces advanced FIFO-based
memory units within the NoC router, assessing their performance
in a Bi-directional NoC (Bi-NoC) configuration. The primary
objective is to reduce the router's workload while enhancing the
FIFO internal structure. To further improve data transfer speed,
a Bi-NoC with a self-configurable intercommunication channel is
suggested. Simulation and synthesis results demonstrate
guaranteed throughput, predictable latency, and equitable
network access, showing significant improvement over previous
designs
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
AI in customer support Use cases solutions development and implementation.pdfmahaffeycheryld
AI in customer support will integrate with emerging technologies such as augmented reality (AR) and virtual reality (VR) to enhance service delivery. AR-enabled smart glasses or VR environments will provide immersive support experiences, allowing customers to visualize solutions, receive step-by-step guidance, and interact with virtual support agents in real-time. These technologies will bridge the gap between physical and digital experiences, offering innovative ways to resolve issues, demonstrate products, and deliver personalized training and support.
https://www.leewayhertz.com/ai-in-customer-support/#How-does-AI-work-in-customer-support
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
Instagram , Facebook etc. Now with high technology E-
Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Height and depth gauge linear metrology.pdfq30122000
Height gauges may also be used to measure the height of an object by using the underside of the scriber as the datum. The datum may be permanently fixed or the height gauge may have provision to adjust the scale, this is done by sliding the scale vertically along the body of the height gauge by turning a fine feed screw at the top of the gauge; then with the scriber set to the same level as the base, the scale can be matched to it. This adjustment allows different scribers or probes to be used, as well as adjusting for any errors in a damaged or resharpened probe.
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
Impartiality as per ISO /IEC 17025:2017 StandardMuhammadJazib15
This document provides basic guidelines for imparitallity requirement of ISO 17025. It defines in detial how it is met and wiudhwdih jdhsjdhwudjwkdbjwkdddddddddddkkkkkkkkkkkkkkkkkkkkkkkwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwioiiiiiiiiiiiii uwwwwwwwwwwwwwwwwhe wiqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq gbbbbbbbbbbbbb owdjjjjjjjjjjjjjjjjjjjj widhi owqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq uwdhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhwqiiiiiiiiiiiiiiiiiiiiiiiiiiiiw0pooooojjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj whhhhhhhhhhh wheeeeeeee wihieiiiiii wihe
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Levelised Cost of Hydrogen (LCOH) Calculator ManualMassimo Talia
The aim of this manual is to explain the
methodology behind the Levelized Cost of
Hydrogen (LCOH) calculator. Moreover, this
manual also demonstrates how the calculator
can be used for estimating the expenses associated with hydrogen production in Europe
using low-temperature electrolysis considering different sources of electricity
Determination of Equivalent Circuit parameters and performance characteristic...pvpriya2
Includes the testing of induction motor to draw the circle diagram of induction motor with step wise procedure and calculation for the same. Also explains the working and application of Induction generator
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
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in the line. In the IPFC the two VSC converters are both inserted in series with two different lines and share a
common dc bus. Hence, they have the capability to precisely control power flow in two different
transmission lines (Figure 1). By using this model, the damping capabilities of the IPFC and UPFC are
compared and some results are obtained. Installing an IPFC or UPFC in constant power control mode for the
series branch has the same effect as disconnecting the transmission line containing the series branch. This
network structure change may be used to improve system damping without requiring the design of a tuned
feedback controller. Theoretically, still there is the possibility of existing poorly damped modes in the
changed network; if there is such a mode, a damping controller which can modulate the power references of
the FACTS device can be introduced. The IPFC has two series branches, while the UPFC has a single series
branch so; the IPFC permits more opportunities for network segmentation. Consequently, the IPFC has
potential for greater damping improvement and also improving the system’s dynamic performance.
Reference [5] is aimed at finding the optimal UPFC control mode and settings to improve the composite
reliability of power systems when all UPFC components are available. The proposed approach will minimize
ESRAC for improving the system reliability. A selected set of contingencies are analyzed and the optimal
power flow (OPF) is used to minimize RAC and calculate the optimal UPFC injections and the sensitivity of
RAC to UPFC injections. The results of contingency analyses are used to calculate post-contingency
injections of UPFC and to estimate the ESRAC associated with control modes and settings. The optimal
UPFC control mode and settings are obtained by solving the proposed mixed-integer nonlinear optimization
problem. The two-source power injection model shown in Figure 2 is used to represent the UPFC in optimal
power flow studies. In this model, parallel source (PS) and series source (SS) are connected to PB and SB,
respectively, so that the total real power injection of PS and SS is zero:
(1)
In Figure 2, once the three independent injections of PS and SS (i.e., , ) are known,
the voltage and current of series and parallel inverters in Figure 1 are calculated as follows:
(2)
(3)
∠ (4)
∠ (5)
Figure 1. Converter-based FACTS
Control modes associated with series and parallel inverters are also considered for PS and SS,
respectively, as:
series
1
2
3
(6)
1
2
(7)
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345
Figure 2. Two-source power injection model for UPFC
The two-state up/down model is used for reliability studies. The proposed method finds the optimal
control mode and settings when the UPFC is in the up state. The method can further be extended to include
other operating states of UPFCs. In Reference [6] the UPFC is connected at the midpoint of the Transmission
line. The basic components of the UPFC are two voltage source inverters (VSIs) sharing a common DC
storage capacitor, and connected to the system through coupling transformers. One VSI is connected in shunt
to the transmission system via a shunt transformer, whereas the other one is connected in series through a
series transformer (Figure 3).
Figure 3. UPFC based transmission system, a) Transmission system with UPFC
b) UPFC-based transmission line model
The UPFC control system is divided into two parts, STATCOM control and SSSC control. The
STATCOM is controlled to operate the VSI for reactive power generation at the connecting point voltage V
ref. The voltages at the connecting points are sent to the phase locked- loop (PLL) to calculate the reference
angle, which is synchronized to the reference phase voltage. The currents are decomposed into the direct and
quadrature components, Id and Iq by a d-q transformation using the PLL angle as reference. The magnitude
of the positive sequence component of the connecting point voltage is compared with V ref and the error is
passed through the PI controller to generate I qref. The reactive part of the shunt current is compared with I qref
and the error is passed through the PI controller to obtain the relative phase angle of the inverter voltage with
respect to the reference phase voltage. This phase angle and the PLL signal are fed to the STATCOM firing
circuit to generate the desired pulse for the VSI. The series injected voltage is determined by the closed loop
control system to ensure that the desired active and reactive power flow occurs despite power system
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changes. The desired P ref and Q ref are compared with the measured active and reactive power flow in the
transmission line, and the error is passed through the PI controller to derive the direct and quadrature
components of the series inverter voltage, V dref and V qref. Thus, the series injected voltage and phase angle
can be found out from the rectangular to polar conversion of the V dref and V qref. The dead angle (found out
from the inverter voltage and DC link voltage), phase angle and the PLL signal are fed to the firing circuit to
generate the desired pulse for the SSSC VSI.
Figure 4. Successive representation of a UPFC and its associated line
The dynamic model of a UPFC is used by a large number of researchers for dynamic analysis of a power
system [8]-[13]. The UPFC and the associated transmission line are separately shown in Figure 4 where the
UPFC is represented by a series voltage source and a shunt current source . Note that and ̅ are not
constant but depend on the control strategy used. For simplicity, the line is first represented by only its series
reactance . The leakage reactance of the series injection transformer (if any) can be included in . The
voltage source in series with can be represented by a current source in parallel with as shown in
Figure 3(b).
(8)
Without loss of generality, the current source between buses and can be replaced by two shunt current
sources (at buses and). Such an equivalent circuit is shown in Figure 3(c) where:
̅ ̅ ̅ ̅ (9)
Figure 5. UPFC components and their classification into three subsystems
Figure 3(d) represents the -circuit model of a UPFC and its associated transmission line. The
UPFC model can also be used to represent an SSSC or a STATCOM by selecting appropriate values of
and . For an SSSC, it is necessary to set 0 and thus ̅ of (4) simply becomes . In this case, is
kept in quadrature with the prevailing line current. However, for a STATCOM, (and hence ) is to be
set to zero. A large number of researchers [14]-[18] used the UPFC system which is classified into three
subsystems: the converters and capacitor link (CL) as subsystem 1, the coupling and intermediate
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347
transformers as subsystem 2 and the controller with the corresponding measuring equipment as subsystem 3.
In order to develop a reliability model of a UPFC, the aforementioned subsystems must be modeled followed
by the development of a complete reliability model of the UPFC. The world’s first UPFC, which was
commissioned in June 1998 at the Inez substation of American Electric Power in Kentucky, has been
modified in their researches as shown in Figure 5.
Figure 6. Unified power flow controller diagram
The actual Inez UPFC comprises two identical gate turn off (GTO) thyristor-based converters. Each
converter includes multiple high-power GTO valve structures feeding an intermediate transformer. The
converter output is coupled to the transmission line by a conventional main coupling transformer. To
maximize the versatility of the installation, two identical main shunt transformers and a single main series
transformer have been provided. With this arrangement, a number of power circuit configurations are
possible. Reference [19], [20] has used another model of UPFC as shown in Figure 6. The series connected
inverter injects a voltage with controllable magnitude and phase angle in series with the transmission line,
thereby providing active and reactive power to the transmission line. The shunt-connected inverter provides
the active power drawn by the series branch and the losses and can independently provide reactive
compensation to the system. The UPFC state model is:
cos ∝ (10)
sin sin (11)
cos cos (12)
sin sin (13)
cos sin cos ∝ sin
1 2− (14)
The currents and are the dq components of the shunt current. The currents and are the dq
components of the series current. The voltages ∠ and ∠ are the shunt and series voltage magnitudes
and angles, respectively. is the voltage across the dc capacitor, represents the switching losses,
and are the shunt transformer resistance and inductance, respectively, and and are the series
transformer resistance and inductance, respectively. The control parameters and∝ ∝ are,
respectively, the modulation gain and voltage phase angle of the shunt (series) injected voltage. The power
balance equations at bus 1 (sending) are:
0= cos sin ) ∑ (15)
0= cos )- ∑ (16)
And at bus 2 (receiving)
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0= cos sin ∑ cos (17)
0= ∑ (18)
Figure 7 shows a power injection model of the UPFC. The series branch shows the series injected
voltage and the shunt branch with voltage controlled by and ∝ . Combining (10)-(18) yields nine
equations with thirteen unknowns; therefore, additional constraints are necessary to fully determine the
operating equilibrium. In the power injection model, three parameters may be arbitrarily set: the shunt bus
voltage magnitude and the series active and reactive powers such that:
+ (19)
- (20)
Where , and are the specified desired values. The schematic representation of the UPFC is shown
in Figure 8 [21], [22]. It consists of two voltage source converters and a dc circuit represented by the
capacitor. Converter 1 is primarily used to provide the real power demand of converter 2 at the common dc
link terminal from the ac power system. Converter 1 can also generate or absorb reactive power at its ac
terminal, which is independent of the active power transfer to (or from) the dc terminal. Therefore, with
proper control, it can also fulfill the function of an independent advanced static VAR compensator providing
reactive power compensation for the transmission line and thus executing indirect voltage regulation at the
input terminal of the UPFC. Converter 2 is used to generate a voltage source at the fundamental frequency
with variable amplitude 0 and phase angle 0 2 , which is added to the ac
transmission line by the series-connected boosting transformer. The inverter output voltage injected in series
with line can be used for direct voltage control, series compensation, phase shifter, and their combinations.
This voltage source can internally generate or absorb all the reactive power required by the different type of
controls applied and transfers active power at its dc terminal. The equivalent circuit of UPFC placed in line-
connected between bus- and bus- is shown in Fig. 9. UPFC has three controllable parameters, namely, the
magnitude and the angle of inserted voltage , and the magnitude of the current .
Figure 7. UPFC equivalent model
Figure 8. Schematic diagram of UPFC
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Figure 9. Equivalent circuit of UPFC
Figure 10. AC-side representation of shunt elements
Based on the principle of UPFC and the vector diagram, the basic mathematical relations can be given as:
′
, 2⁄
and
′
(21)
The power flow equations from bus-i to bus-j and from bus-jto bus-i can be written as:
∗ ′ ∗
(22)
∗ ′ ∗
(23)
Active and reactive power flows in the line having UPFC can be written, with (21)-(23), as:
2 cos cos
(24)
2
2 cos (25)
References [23]-[25] discuss the harmonic-domain representation of pulse width-modulated (PWM)
converters and their application to the unified power-flow controller (UPFC). The UPFC can be modeled at
harmonic frequencies by considering two PWM switching spectra and their interaction on both the ac and dc
sides of the converter.
2.1. PWM Converter Representation
Since power-electronic converters are, in principle, switching modulators, they can be characterized
in terms of the harmonic transfers between the ac and dc sides. This implementation reduces the storage
requirements for each harmonic phasor by recognizing the conjugated nature of negative frequency terms.
Each harmonic phasor is therefore a complex vector of length nh, the highest harmonic of interest. These
harmonic phasors are transferred across a converter via convolution with the converter’s positive frequency
spectra ( of bandwidth 2nh (fulfilling the Nyquist rate). The transfers can therefore be described as:
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⨂ (26)
∑ ⨂ (27)
Where bold text refers to a harmonic phasor, ph refers to phase quantities, and ⨂ represents Smith’s positive
frequency convolution. The PWM spectra are described as a function of the switching instants, each of
which is defined by classical PWM theory. The switching instants are stored in a vector , which contains an
ON and OFF instant for each of the Np conduction periods. The individual instants are calculated with a
single variable Newton scheme at the beginning of each iteration. The result is the PWM switching spectra,
which is defined at the h th harmonic as:
∑ P P), h=0 (28)
∑ (29)
Figure 11. AC-side representation of series elements
2.2. Shunt and Series Connections
Since FACTS devices use predominantly voltage source conversion, it is convenient and logical to
include shunt converters as harmonic voltage sources (Figure 10). This approach, unlike shunt current
injection models, does not require knowledge about the terminal voltage to make the voltage source
substitution. This logic does not extend to series converters where, in order to avoid voltage dependence
problems, it is more concise to use a pair of opposing shunt current sources (Figure 11). This representation
is possible since the injected current can be defined in terms of the converter voltage and transformer leakage
impedance both of which are known:
(30)
This representation maintains the generality of the solution format, allowing the UPFC to be
modeled by combining a shunt and series representation. It is important to note that these models are only
used to formulate the harmonic mismatches, a conventional dual voltage source representation being used
within the power flow.
2.3. AC-Side Harmonic Interaction
Since the interaction between the series and shunt equivalent circuits is assumed to occur across a
predominantly linear network, they are easily combined using traditional circuit analysis First consider the
system admittance matrix, which has been partitioned into sub matrices A –J , according to the type of
harmonic injection present at each busbar.
(31)
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Where refers to ideal voltage-source busbars (e.g., the voltage source component of the system
equivalent Vinf ), the voltage at harmonic current injection busbars (Vi and Vj in Figure 12), and
the harmonic voltage-source busbars (Vshunt in Figure 11). All other busbars (e.g., load busbars) are
treated as harmonic current injection busbars with the harmonic injection set to zero. By assuming that no
voltage harmonics are present at the ideal voltage sources, it is possible to describe the unknown current
flows ( at the harmonic voltage source busbars and the unknown voltages at the harmonic
current injection busbars:
I
(32)
These effectively describe the harmonic interaction between any number of harmonic voltage or
current sources used to represent FACTS devices. The mathematical UPFC model was derived with the aim
of being able to study the relations between the electrical transmission system and UPFC in steady-state
conditions [26]. The basic scheme of this model is shown in Figure 12.This figure represents a single-line
diagram of a simple transmission line with a resistance, an inductive reactance, a UPFC, a sending-end
voltage source , and a receiving-end voltage source , respectively. According to Figure 13, the currents
, and are calculated by the following expressions:
I (33)
I
(34)
I (35)
Where,
(36)
Figure 14 shows the single-line diagram of a UPFC connected at the end of the transmission line. The vector
diagram of an UPFC connected to a network (Figure 13) is presented in Figure 14. According to Figure 15,
and are the components of the series voltage of UPFC. They are proportional to the voltage at the
point of connection of UPFC and can be written as:
(37)
Where and are the control variables. Neglecting network losses, the electrical power can be
expressed as:
′
sin
′
(38)
Figure 12. Mathematical model of a UPFC installed in a transmission line
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Figure 13. Generator-infinite bus system with the UPFC
Figure 14. Vector diagram of a UPFC connected to a network
Where X is the equivalent transient reactance which includes the transient reactance of generator, the
reactance of the transformer and the transmission line. The generator swing equation is:
(39)
Where:
′
Asin δ (40)
Where introduces additional damping to the system if it is positive and proportional to the speed
deviation . This can be achieved through the following control strategy:
(41)
By replacing (41) in (40), the damping factor is represented as below:
. (42)
According to Figure 15, there are the following equations:
′
cos (43)
′
sin (44)
Then:
′
sin (45)
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Figure 15. Control block diagram of a STATCOM Figure 16. Modulation controller for Vp and Vq
′
cos (46)
The partial derivative of is calculated as:
′
(47)
The partial derivative of is also calculated as:
′
(48)
The shunt converter has two duties:
a) Control the voltage magnitude at the sending-end bus by locally generating (or absorbing)
reactive power.
b) Supply or absorb real power at the dc terminals as demanded by the series converter.
The general block diagram of the shunt part control is given in Figure 16. Figure 16 shows the
proposed block diagram of a modulation controller capable of producing a real differentiating element with a
small time constant T. The value of K is chosen so that the injected series voltage remains at its nominal
value. The values of and ′
are chosen as 1 p.u. The modeling of series and parallel parts of UPFC [27],
[28] can be represented respectively by the following equations expressed in a d,q rotating system, which is
defined such that the q component of the voltage at the second bus equals to zero (Figure 17.):
Figure 17. Simplified electric scheme of a 2-level UPFC
. (49)
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(50)
, (51)
and represent respectively the voltage ratios of the series and parallel transformers. The
transfer functions related to these two equations expressed in per unit and represented in the Laplace domain
are given in Table 1.
Table 1. Type Sizes for Papers
SERIES PART SHUNT PART
1
1
Whit
1
1
Whit
3. CONCLUSION
The paper has presented different models of UPFC in some papers in recent years. Steady-state,
dynamic, mathematical model, UPFC control model, harmonic domain UPFC model of unified power flow
controller (UPFC) reported in this paper.
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BIOGRAPHIES OF AUTHORS
Mahmoud Zadehbagheri was born in Yasouj, Iran in October 1979. In 2003 he received his
B.S. in Electrical Engineering from Kashan University and in 2008 he received his M.S. in
Electrical Engineering from the Islamic Azad University, Najafabad Branch, he is currently
pursuing your PhD at Sabzevar university. He is with the faculty of the Electrical Engineering
Department, Islamic Azad University of Yasouj. His research interests include the fields of
power electronics, electrical machines and drives, FACTS devices and Power Quality.
Rahim Ildarabadi was born in Sabzevar, Iran in 1975. He received the PhD degree from
Ferdowsi University of Mashhad in 2010. He is a full time faculty member at Sabzevar Hkim
Sabzevari University. His main area of interest are automation system, electrical machine derive,
renewable energy, instruments and measurement. He is currently an Assistant Professor of
electrical engineering at Hakim SabzevariUniversity.
Majid Baghaei Nejad received the B.S. and M.Sc degree in electrical engineering from
Ferdowsi University, and Tarbiat Modares University, Iran, in 1996 and 2000 respectively, and
his PhD degree in electronic and computer systems from Royal Institute of Technology (KTH),
Stockholm, Sweden in 2008. Since 2000 he has been with electronics department at Hakim
Sabzevari University, Iran, where currently has an assistance professor position. His current
research work includes low power analog/RF integrated circuit design, ultra wideband
communication, RFID systems and wireless sensing.