One of the best solutions to improve power quality is the dynamic voltage restorer (DVR). DVR is a kind of
custom power devices that can inject active/reactive power to the power grids. This can protect loads from
disturbances such as sag and swell. Usually DVR installed between sensitive loads feeder and source in
distribution system. Its features include lower cost, smaller size, and its fast dynamic response to the
disturbance. In this project SRF technique is used for conversion of voltage from rotating vectors to the
stationary frame. SRF technique is also referred as park’s transformation. In this the reference load voltage is
estimated using the unit vectors. The real power exchanged at the DVR output ac terminal is provided by the
DVR input dc terminal by an external energy source or energy storage system. In this project three phase
parallel or series load may be used along with SRF technique to compensate voltage sag and voltage swell. And
also wind generator is also used as a load. This project presents the simulation of DVR system using
MATLAB/SIMULINK.
Enhancement of Power Quality Problem by Using Dynamic Voltage RestorerAM Publications
Dynamic voltage restorers (DVRs) are used to protect sensitive loads from the effects of voltage sags on the
distribution feeder. This paper presents and verifies a novel voltage sag detection technique for use in conjunction
with the main control system of a DVR. In all cases it is necessary for the DVR control system to not only detect the
start and end of a voltage sag but also to determine the sag depth and any associated phase shift. The DVR, which is
placed in series with a sensitive load, must be able to respond quickly to a voltage sag if end users of sensitive
equipment are to experience no voltage sag. The DVR can restore the load voltage within few milliseconds. A control
technique based on a proportional–integral (PI) controller and a selective controller is used. The controller is
designed in a synchronously-rotating reference frame. In fact, three independent controllers have been used to tackle
balanced and unbalanced voltage supplies. Simulation results using ‘MATLAB SIMULINK’ Sim Power System
Toolbox is presented to illustrate the principle and performance of a DVR operation in load voltage compensation.
COMPENSATION OF SAGS AND SWELLS VOLTAGE USING DYNAMIC VOLTAGE RESTORER (DVR) ...Asoka Technologies
This paper deals with modeling and simulation technique of a Dynamic Voltage Restore (DVR). The DVR is a dynamic solution to protect sensitive loads against voltage sags and swells. The DVR can be implemented to protect a group of medium voltage or low voltage consumers. The new configuration of DVR has been proposed using improved d-q-0 controller technique. This study presents compensation of sags and swells voltage during single line to ground (SLG) fault and three-phase fault. Simulation results carried out by Matlab/Simulink verify the performance of the proposed method.
In this paper, different voltage injection schemes for dynamic voltage restorers (DVRs) are analyzed with particular focus on a new method used to minimize the rating of the voltage source converter (VSC) used in DVR. A new control technique is proposed to control the capacitor-supported DVR. The control of a DVR is demonstrated with a reduced-rating VSC. The reference load voltage is estimated using the unit vectors. The synchronous reference frame theory is used for the conversion of voltages from rotating vectors to the stationary frame. The compensation of the voltage sag, swell, and harmonics is demonstrated using a reduced-rating DVR.
Power quality problems such as transients, sags, swells, and other distortions to the sinusoidal waveform of the supply voltage affect the performance of these equipment pieces. Technologies such as custom power devices are emerged to provide protection against power quality problems. Custom power devices are mainly of three categories such as series-connected compensators known as dynamic voltage restorers (DVRs), shunt-connected compensators such as distribution static compensators, and a combination of series and shunt-connected compensators known as unified power quality conditioner. The DVR can regulate the load voltage from the problems such as sag, swell, and harmonics in the supply voltages. Hence, it can protect the critical consumer loads from tripping and consequent losses . The custom power devices are developed and installed at consumer point to meet the power quality standards such as IEEE-519 .
Voltage sags in an electrical grid are not always possible to avoid because of the finite clearing time of the faults that cause the voltage sags and the propagation of sags from the
Transmission and distribution systems to the low-voltage loads. Voltage sags are the common reasons for interruption in production plants and for end-user equipment malfunctions in general. In particular, tripping of equipment in a production line can cause production interruption and significant costs due to loss of production. One solution to this problem is to make the equipment itself more tolerant to sags, either by intelligent control or by storing “ride-through” energy in the equipment. An alternative solution, instead of modifying each component in a plant to be tolerant against voltage sags, is to install a plant wide uninterruptible power supply system for longer power interruptions or a DVR on the incoming supply to mitigate voltage sags for shorter periods [8]–[23]. DVRs can eliminate most of the sags and minimize the risk of load tripping for very deep sags, but their main drawbacks are their standby losses, the equipment cost, and also the protection
Scheme required for downstream short circuits.
Enhancement of Power Quality Problem by Using Dynamic Voltage RestorerAM Publications
Dynamic voltage restorers (DVRs) are used to protect sensitive loads from the effects of voltage sags on the
distribution feeder. This paper presents and verifies a novel voltage sag detection technique for use in conjunction
with the main control system of a DVR. In all cases it is necessary for the DVR control system to not only detect the
start and end of a voltage sag but also to determine the sag depth and any associated phase shift. The DVR, which is
placed in series with a sensitive load, must be able to respond quickly to a voltage sag if end users of sensitive
equipment are to experience no voltage sag. The DVR can restore the load voltage within few milliseconds. A control
technique based on a proportional–integral (PI) controller and a selective controller is used. The controller is
designed in a synchronously-rotating reference frame. In fact, three independent controllers have been used to tackle
balanced and unbalanced voltage supplies. Simulation results using ‘MATLAB SIMULINK’ Sim Power System
Toolbox is presented to illustrate the principle and performance of a DVR operation in load voltage compensation.
COMPENSATION OF SAGS AND SWELLS VOLTAGE USING DYNAMIC VOLTAGE RESTORER (DVR) ...Asoka Technologies
This paper deals with modeling and simulation technique of a Dynamic Voltage Restore (DVR). The DVR is a dynamic solution to protect sensitive loads against voltage sags and swells. The DVR can be implemented to protect a group of medium voltage or low voltage consumers. The new configuration of DVR has been proposed using improved d-q-0 controller technique. This study presents compensation of sags and swells voltage during single line to ground (SLG) fault and three-phase fault. Simulation results carried out by Matlab/Simulink verify the performance of the proposed method.
In this paper, different voltage injection schemes for dynamic voltage restorers (DVRs) are analyzed with particular focus on a new method used to minimize the rating of the voltage source converter (VSC) used in DVR. A new control technique is proposed to control the capacitor-supported DVR. The control of a DVR is demonstrated with a reduced-rating VSC. The reference load voltage is estimated using the unit vectors. The synchronous reference frame theory is used for the conversion of voltages from rotating vectors to the stationary frame. The compensation of the voltage sag, swell, and harmonics is demonstrated using a reduced-rating DVR.
Power quality problems such as transients, sags, swells, and other distortions to the sinusoidal waveform of the supply voltage affect the performance of these equipment pieces. Technologies such as custom power devices are emerged to provide protection against power quality problems. Custom power devices are mainly of three categories such as series-connected compensators known as dynamic voltage restorers (DVRs), shunt-connected compensators such as distribution static compensators, and a combination of series and shunt-connected compensators known as unified power quality conditioner. The DVR can regulate the load voltage from the problems such as sag, swell, and harmonics in the supply voltages. Hence, it can protect the critical consumer loads from tripping and consequent losses . The custom power devices are developed and installed at consumer point to meet the power quality standards such as IEEE-519 .
Voltage sags in an electrical grid are not always possible to avoid because of the finite clearing time of the faults that cause the voltage sags and the propagation of sags from the
Transmission and distribution systems to the low-voltage loads. Voltage sags are the common reasons for interruption in production plants and for end-user equipment malfunctions in general. In particular, tripping of equipment in a production line can cause production interruption and significant costs due to loss of production. One solution to this problem is to make the equipment itself more tolerant to sags, either by intelligent control or by storing “ride-through” energy in the equipment. An alternative solution, instead of modifying each component in a plant to be tolerant against voltage sags, is to install a plant wide uninterruptible power supply system for longer power interruptions or a DVR on the incoming supply to mitigate voltage sags for shorter periods [8]–[23]. DVRs can eliminate most of the sags and minimize the risk of load tripping for very deep sags, but their main drawbacks are their standby losses, the equipment cost, and also the protection
Scheme required for downstream short circuits.
Practically, the capability of injection voltage by DVR system is 50% of nominal voltage. This allows DVRs to successfully provide protection against sags to 50% for durations of up to 0.1 seconds. Furthermore, most voltage sags rarely reach less than 50%.
Mitigation of Voltage Sag/Swell using Custom Power Devices with SMES System i...Editor IJMTER
Any power problem noticed in voltage, current or frequency deviations that results in
misoperation of customer or end user equipment. The new method of dynamic voltage restorer with
SMES is proposed to protect consumers load from tripping .The DVR can effectively inject the
voltage to the power lines. To improve the performance of DVR the superconducting magnet is
selected as the energy storage unit. The compensation of the voltage sag, swell by short period of
voltage injection. SMES based DVR has been used to improve the performance of power system. It
is having high power rating with maximum efficiency than any other energy storage devices. It
restores line voltage to its nominal value within few milliseconds. Most of the power quality
problems are voltage sag, swell, interruption, transient, fluctuation, etc.. Among those power quality
problem voltage sag is severe one. So it is analyzing and mitigated using custom power device and
SMES system using MATLAB SIMULINK in proposed system.
This paper gives a systematic technique of the design and simulation of Dynamic Voltage Restorer (DVR) the use of Sinusoidal Pulse Width Modulation (SPWM). though electricity great associated problems like voltage sags/swells arise both at the transmission aspect as well as the distribution facet, the terminology used for the compensation devices is exclusive. DVR is a series linked tool used for compensating voltage sags and swells at the distribution side. on this work, a step by step technique is given to determine out the additives which can be required for the layout and simulation of DVR. The detection of sags/swells is completed with the assist of d-q-o concept, whereas the manager of the voltage source inverter is achieved with the assist of SPWM. The VSI has been applied with the assist of both Bipolar SPWM in addition to Unipolar SPWM and the results were compared. The simulation becomes achieved with the help of SIMULINK & MATLAB and the consequences have been located to be in accordance with concept.
this is useful for peoples interested in power quality problems and their mitigation. it provides causes, effects of voltage sag and their mitigation techniques.
Power Quality Enhancement through Dynamic Voltage Restorer using SRF Theory f...IJERD Editor
Power quality is certainly a major concern in the present era, it becomes especially important with
the introduction of sophisticated devices, whose performance is very sensitive to the quality of power supply.
Voltage sag is one of the severe power quality problems. This report addresses all the different aspects related to
voltage sag problem, such as its types, consequences and mitigation.
At present, a wide range of very flexible controllers, which capitalize on newly available power electronics
components, are emerging for custom power applications. Among these, the distribution static compensator (DSTATCOM)
and the dynamic voltage restorer (DVR) are most effective devices, both of them based on the
VSC principle.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
An enhanced voltage sag compensation scheme for dynamic voltage restorerLeMeniz Infotech
An enhanced voltage sag compensation scheme for dynamic voltage restorer
To Get this projects Call : 9566355386 / 99625 88976
Visit : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
VOLTAGE SAG AND SWELL ALLEVIATION IN DISTRIBUTION NETWORK USING CUSTOM POWER...Gaddafi Sani
IEEE-Pemc 2014 conference: VOLTAGE SAG AND SWELL ALLEVIATION IN DISTRIBUTION NETWORK USING CUSTOM POWER DEVICES; D-STATCOM AND DVR. by Abdullahi Kunya, T. Yalcinoz, Gaddafi Shehu
Characteristics Analysis of Voltage Sag in Distribution System using RMS Volt...IDES Editor
Voltage sags caused by the short-circuit faults in
transmission and distribution lines have become one of the
most important power quality problems facing industrial
customers and utilities. Voltage sags are normally described
by characteristics of both magnitude and duration, but phaseangle
jump should be taken into account in identifying sag
phenomena and finding their solutions. In this paper, voltage
sags due to power system faults such as three-phase-to-ground,
single phase-to-ground, phase-to-phase, and two-phase-toground
faults are characterized by using symmetrical
component analysis and their effect on the magnitude
variation and phase-angle jumps for each phase are examined.
A simple and practical method is proposed for voltage sag
detection, by calculating RMS voltage over a window of one
cycle and one-half cycle. The industrial distribution system
at Bajaj hospital is taken as a case study. Simulation studies
have been performed by suing MATLAB/SIMULINK and the
results are presented at various magnitudes, duration and
phase-angle jumps.
—In this paper, different voltage injection schemes for
dynamic voltage restorers (DVRs) are analyzed with particular
focus on a new method used to minimize the rating of the voltage
source converter (VSC) used in DVR. A new control technique is
proposed to control the capacitor-supported DVR. The control of
a DVR is demonstrated with a reduced-rating VSC. The reference
load voltage is estimated using the unit vectors. The synchronous
reference frame theory is used for the conversion of voltages from
rotating vectors to the stationary frame. The compensation of
the voltage sag, swell, and harmonics is demonstrated using a
reduced-rating DVR.
Power Quality Solutions: Dynamic Voltage RestorerRoshan Pais
An innovative solution to ensure high quality voltage supply by compensating for Flicker, Dips and Sags. High energy efficiency leading to low operational and maintenance costs.
The aim of this paper is to analyze the performance of the three-phase squirrel cage induction motor under various voltage fluctuation levels. Generally, Induction motor drives are preferred for its simple and easy control. Their performance depends on relative power supply quality such as voltage sag, harmonics, voltage unbalance and voltage fluctuations. The induction motor is more sensitive to voltage fluctuations within certain amplitude levels and frequencies. This paper presents a study of voltage sag effects on an induction motor using simulation. In this paper, the impact of voltage fluctuations on induction motor performance is investigated. S. Sakthivel"Effect of Voltage Sag on an Induction Motor" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18298.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18298/effect-of-voltage-sag-on-an-induction-motor/s-sakthivel
Power Quality Improvement Using A DVR (Dynamic Voltage Restorer)
ABSTRACT
Power quality is one of major problems in the today’s scenario. It has become important with the introduction of complex devices, whose performance is very sensitive to the quality of power supply. Power quality problem is an occurrence developed as a nonstandard voltage, current or frequency that results in a failure of end use equipment. Some of the major problems dealt here is the power sag and swell. This paper describes the effectiveness of using dynamic voltage restorer (DVR) in order to mitigate voltage sags and swells in low voltage distribution systems. Dynamic Voltage Restorer can provide the most cost effective solution to mitigate voltage sags and swells that is required by customer. The Dynamic Voltage Restorer (DVR) is a rapid, flexible and resourceful solution to power quality problems.
POWER QUALITY IMPROVEMENT AND FAULT RIDE THROUGH OF GRID CONNECTED WIND ENE...Bharadwaj S
This work tries to improve the power quality by compensating reactive power with Active Power Filters and also to analyze Fault Ride Through of Grid connected wind energy conversion systems.
Practically, the capability of injection voltage by DVR system is 50% of nominal voltage. This allows DVRs to successfully provide protection against sags to 50% for durations of up to 0.1 seconds. Furthermore, most voltage sags rarely reach less than 50%.
Mitigation of Voltage Sag/Swell using Custom Power Devices with SMES System i...Editor IJMTER
Any power problem noticed in voltage, current or frequency deviations that results in
misoperation of customer or end user equipment. The new method of dynamic voltage restorer with
SMES is proposed to protect consumers load from tripping .The DVR can effectively inject the
voltage to the power lines. To improve the performance of DVR the superconducting magnet is
selected as the energy storage unit. The compensation of the voltage sag, swell by short period of
voltage injection. SMES based DVR has been used to improve the performance of power system. It
is having high power rating with maximum efficiency than any other energy storage devices. It
restores line voltage to its nominal value within few milliseconds. Most of the power quality
problems are voltage sag, swell, interruption, transient, fluctuation, etc.. Among those power quality
problem voltage sag is severe one. So it is analyzing and mitigated using custom power device and
SMES system using MATLAB SIMULINK in proposed system.
This paper gives a systematic technique of the design and simulation of Dynamic Voltage Restorer (DVR) the use of Sinusoidal Pulse Width Modulation (SPWM). though electricity great associated problems like voltage sags/swells arise both at the transmission aspect as well as the distribution facet, the terminology used for the compensation devices is exclusive. DVR is a series linked tool used for compensating voltage sags and swells at the distribution side. on this work, a step by step technique is given to determine out the additives which can be required for the layout and simulation of DVR. The detection of sags/swells is completed with the assist of d-q-o concept, whereas the manager of the voltage source inverter is achieved with the assist of SPWM. The VSI has been applied with the assist of both Bipolar SPWM in addition to Unipolar SPWM and the results were compared. The simulation becomes achieved with the help of SIMULINK & MATLAB and the consequences have been located to be in accordance with concept.
this is useful for peoples interested in power quality problems and their mitigation. it provides causes, effects of voltage sag and their mitigation techniques.
Power Quality Enhancement through Dynamic Voltage Restorer using SRF Theory f...IJERD Editor
Power quality is certainly a major concern in the present era, it becomes especially important with
the introduction of sophisticated devices, whose performance is very sensitive to the quality of power supply.
Voltage sag is one of the severe power quality problems. This report addresses all the different aspects related to
voltage sag problem, such as its types, consequences and mitigation.
At present, a wide range of very flexible controllers, which capitalize on newly available power electronics
components, are emerging for custom power applications. Among these, the distribution static compensator (DSTATCOM)
and the dynamic voltage restorer (DVR) are most effective devices, both of them based on the
VSC principle.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
An enhanced voltage sag compensation scheme for dynamic voltage restorerLeMeniz Infotech
An enhanced voltage sag compensation scheme for dynamic voltage restorer
To Get this projects Call : 9566355386 / 99625 88976
Visit : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
VOLTAGE SAG AND SWELL ALLEVIATION IN DISTRIBUTION NETWORK USING CUSTOM POWER...Gaddafi Sani
IEEE-Pemc 2014 conference: VOLTAGE SAG AND SWELL ALLEVIATION IN DISTRIBUTION NETWORK USING CUSTOM POWER DEVICES; D-STATCOM AND DVR. by Abdullahi Kunya, T. Yalcinoz, Gaddafi Shehu
Characteristics Analysis of Voltage Sag in Distribution System using RMS Volt...IDES Editor
Voltage sags caused by the short-circuit faults in
transmission and distribution lines have become one of the
most important power quality problems facing industrial
customers and utilities. Voltage sags are normally described
by characteristics of both magnitude and duration, but phaseangle
jump should be taken into account in identifying sag
phenomena and finding their solutions. In this paper, voltage
sags due to power system faults such as three-phase-to-ground,
single phase-to-ground, phase-to-phase, and two-phase-toground
faults are characterized by using symmetrical
component analysis and their effect on the magnitude
variation and phase-angle jumps for each phase are examined.
A simple and practical method is proposed for voltage sag
detection, by calculating RMS voltage over a window of one
cycle and one-half cycle. The industrial distribution system
at Bajaj hospital is taken as a case study. Simulation studies
have been performed by suing MATLAB/SIMULINK and the
results are presented at various magnitudes, duration and
phase-angle jumps.
—In this paper, different voltage injection schemes for
dynamic voltage restorers (DVRs) are analyzed with particular
focus on a new method used to minimize the rating of the voltage
source converter (VSC) used in DVR. A new control technique is
proposed to control the capacitor-supported DVR. The control of
a DVR is demonstrated with a reduced-rating VSC. The reference
load voltage is estimated using the unit vectors. The synchronous
reference frame theory is used for the conversion of voltages from
rotating vectors to the stationary frame. The compensation of
the voltage sag, swell, and harmonics is demonstrated using a
reduced-rating DVR.
Power Quality Solutions: Dynamic Voltage RestorerRoshan Pais
An innovative solution to ensure high quality voltage supply by compensating for Flicker, Dips and Sags. High energy efficiency leading to low operational and maintenance costs.
The aim of this paper is to analyze the performance of the three-phase squirrel cage induction motor under various voltage fluctuation levels. Generally, Induction motor drives are preferred for its simple and easy control. Their performance depends on relative power supply quality such as voltage sag, harmonics, voltage unbalance and voltage fluctuations. The induction motor is more sensitive to voltage fluctuations within certain amplitude levels and frequencies. This paper presents a study of voltage sag effects on an induction motor using simulation. In this paper, the impact of voltage fluctuations on induction motor performance is investigated. S. Sakthivel"Effect of Voltage Sag on an Induction Motor" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18298.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18298/effect-of-voltage-sag-on-an-induction-motor/s-sakthivel
Power Quality Improvement Using A DVR (Dynamic Voltage Restorer)
ABSTRACT
Power quality is one of major problems in the today’s scenario. It has become important with the introduction of complex devices, whose performance is very sensitive to the quality of power supply. Power quality problem is an occurrence developed as a nonstandard voltage, current or frequency that results in a failure of end use equipment. Some of the major problems dealt here is the power sag and swell. This paper describes the effectiveness of using dynamic voltage restorer (DVR) in order to mitigate voltage sags and swells in low voltage distribution systems. Dynamic Voltage Restorer can provide the most cost effective solution to mitigate voltage sags and swells that is required by customer. The Dynamic Voltage Restorer (DVR) is a rapid, flexible and resourceful solution to power quality problems.
POWER QUALITY IMPROVEMENT AND FAULT RIDE THROUGH OF GRID CONNECTED WIND ENE...Bharadwaj S
This work tries to improve the power quality by compensating reactive power with Active Power Filters and also to analyze Fault Ride Through of Grid connected wind energy conversion systems.
Accumulo Summit 2015: Accumulo In-Depth: Building Bulk Ingest [Sponsored]Accumulo Summit
Talk Abstract
Bulk ingest enables Accumulo to import externally-prepared data into existing tables. Unlike ingest via batch writers, much of the work of organizing data can be left to external processing frameworks such as MapReduce and scaled independently of the Accumulo cluster itself. This reduces the work required of the tablet servers to support ingest, freeing resources to support other operations.
Under the hood, bulk ingest involves a number a moving parts and accounting for a variety of failure scenarios. This talk covers the components of the bulk ingest process in-depth and describes past, current and future implementations of this capability. Attendees will leave this session with an understanding of bulk ingest that will enable troubleshooting, capacity estimation and performance management.
Speaker
Eric Newton
Senior Software Developer, SWComplete
Eric Newton has been a programmer for over 30 years, and has worked on Accumulo since 2009. He has been an open-source contributor and consumer since 1988. Through the years, his distributed communications systems work has included Air Traffic Control, Systems Monitoring and Databases. Eric has started 3 of his own companies and helped several other businesses start.
Voltage Flicker Analysis and its Mitigation by STATCOM for Power Quality Impr...IJMTST Journal
Voltage flicker is considered as one of the most severe power quality problems (especially in loads like electrical arc furnaces) and much attention has been paid to it lately. The reason for this disturbance is mainly due to the large nonlinear loads such as electric arc furnaces. Due to the latest achievements in the semiconductors industry and consequently the emergence of the compensators based on voltage source converters, FACTS devices have been gradually noticed to be used for voltage flicker compensation. This paper covers the contrasting approaches; dealing with the voltage flicker mitigation in three stages and assessing the related results in details. Initially, the voltage flicker mitigation, using FCTCR (Fixed Capacitor Thyristor Controlled Reactor), was simulated. Secondly, the compensation for the Static Synchronous Compensator (STATCOM) has been performed. The voltage flicker compensation by 8– pulse as well as 12 – pulse static synchronous compensator (STATCOM) has been performed. This paper deals with the voltage flicker mitigation and reduction in total harmonic distortion (THD) and compared the results in detail. The obtained results show that STATCOM is very efficient and effective for the compensation and mitigation of voltage flicker and harmonics all the simulation results have been performed on the MATLAB Software.
IRJET-Review on Power Quality Enhancement in weak Power Grids by Integration ...IRJET Journal
Prathmesh Mayekar, Mahesh Wagh, Nilkanth Shinde "Review on Power Quality Enhancement in weak Power Grids by Integration of Renewable Energy Technologies", International Research Journal of Engineering and Technology (IRJET), Volume2,issue-01 April 2015.e-ISSN:2395-0056, p-ISSN:2395-0072. www.irjet.net
Abstract
During Last decade power quality problems has become more complex at all level of power system. With the increased use of sophisticated electronics, high efficiency variable speed drive, power electronic controllers and also more & more non-linear loads, Power Quality has become an increasing concern to utilities and customers. The modern sensitive, Non-linear and sophisticated load affects the power quality. This paper deals with the issues of low power quality in weak power grids. Initially the various power quality issues are discussed with their definition or occurrence and then finally the solution to mitigate this power quality issues are discussed. The innovative solutions like integration of renewable energy systems along with energy storage to enhance power quality by interfacing with custom power devices are explained in detail. Nearly all sorts of solution for mitigating power quality issue require some sort of DC source for providing active power, which can be supplied by renewable energy source. Also the various energy storage systems are studied.
A Review on Basic Concepts and Important Standards of Power Quality in Power ...Editor IJCATR
This paper deals with the basic of Power quality in power system. In addition basic definition and important concepts was discussed in simple way. This paper also covers the important power quality standards. In addition IEEE, IEC, SEMI and UIE Power quality standards are listed. This paper would be helpful for the UG and PG students to study about the basics of Power quality in electrical engineering.
A Review on Basic Concepts and Important Standards of Power Quality in Power ...Editor IJCATR
This paper deals with the basic of Power quality in power system. In addition basic definition and important concepts was
discussed in simple way. This paper also covers the important power quality standards. In addition IEEE, IEC, SEMI and UIE Power
quality standards are listed. This paper would be helpful for the UG and PG students to study about the basics of Power quality in
electrical engineering.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Non-linear loads can cause transients in electronic switches. They also result in a fluctuating output when the device is switched ON or OFF. These transients can harm not only the switches but also the devices that they are connected to, by passing excess currents or voltages to the devices. By applying machine learning, we can improve the gate drive voltages of the switches and thereby reduce switch transients. A feedback system is built that measures the output transients and then feeds it to a neural network algorithm that then gives a proper gate drive to the device. This will reduce transients and also improve performances of switch based devices like inverters and converters.
Photo Voltaic Cell Integrated DVR for Power Quality ImprovementIJMTST Journal
Grid integration of distributed energy resources (DERs) is increasing rapidly. Integration of various types of energy storage technologies like batteries, ultra capacitors (UCAPs), superconducting magnets and flywheels to support intermittent DERs, such as solar and wind, in order to improve their reliability is becoming necessary. Of all the energy storage technologies UCAPs have low energy density, high power density and fast charge/discharge characteristics. They also have more charge/discharge cycles and higher terminal voltage per module when compared to batteries. All these characteristics make UCAPs ideal choice for providing support to events on the distribution grid which require high power for short spans of time. UCAPs have traditionally been limited to regenerative braking and wind power smoothing applications. The major contribution of this dissertation is in integrating UCAPs for a broader range of applications like active/reactive power support, renewable intermittency smoothing, voltage sag/swell compensation and power quality conditioning to the distribution grid. Renewable intermittency smoothing is an application which requires bi-directional transfer of power from the grid to the UCAPs and vice-versa by charging and discharging the UCAPs. This application requires high active power support in the 10s-3min time scale which can be achieved by integrating UCAPs through a shunt active power filter (APF) which can also be used to provide active/reactive power support. Temporary voltage sag/swell compensation is another application which requires high active power support in the 3s-1min time scale which can be provided integrating UCAPs into the grid through series dynamic voltage restorer (DVR). All the above functionalities can also be provided by integrating the UCAPs into a power conditioner topology.
Modeling and simulation of dynamic voltage restorer for voltage sag mitigatio...IJRRR
Abstract- Power quality deals with utilization of electric energy from the distribution system successfully without interference or interruption. Various factors like interruption in power supply, under voltage, over voltage, unbalanced voltage or current, harmonic distortion, flickering voltage, voltage fluctuation voltage sag etc. result in poor power quality. These power quality related problems can be solved with the help of various custom power devices. Voltage sags are considered to be the most common type of disturbances in the field based on current power disturbances studies. Their impact on sensitive loads is rigorous. The impact ranges from load disruptions to financial losses. In spite of the technical advances in electronics, there are some pieces of equipment that are so sensitive that they are unable to withstand voltage sags. There are many varies methods to mitigate voltage sags, but a Custom Power Supply device is considered to be the most efficient method. This dissertation is the study of Dynamic Voltage Restorer (DVR) which is the most efficient and effective device to protect sensitive equipment against voltage sags. It has low cost, smaller size and it has dynamic response to the disturbance.
Keywords- Voltage sag, DVR, power system, mitigation
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Control of Dvr with Battery Energy Storage System Using Srf Theory
1. B.Kavitha Int. Journal of Engineering Research and Applications www.ijera.com
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Control of Dvr with Battery Energy Storage System Using Srf
Theory
B.Kavitha#
, B.Preethi*
#
Asst.Professor, Electrical and Electronics, Sri Krishna College of Technology, India
*
Final year PG student, Power Systems Engineering, Sri Krishna College of Technology, India
Abstract
One of the best solutions to improve power quality is the dynamic voltage restorer (DVR). DVR is a kind of
custom power devices that can inject active/reactive power to the power grids. This can protect loads from
disturbances such as sag and swell. Usually DVR installed between sensitive loads feeder and source in
distribution system. Its features include lower cost, smaller size, and its fast dynamic response to the
disturbance. In this project SRF technique is used for conversion of voltage from rotating vectors to the
stationary frame. SRF technique is also referred as park’s transformation. In this the reference load voltage is
estimated using the unit vectors. The real power exchanged at the DVR output ac terminal is provided by the
DVR input dc terminal by an external energy source or energy storage system. In this project three phase
parallel or series load may be used along with SRF technique to compensate voltage sag and voltage swell. And
also wind generator is also used as a load. This project presents the simulation of DVR system using
MATLAB/SIMULINK.
Keywords: DVR (Dynamic voltage restorer), VSC (Voltage source converter), PCC (Point of common
coupling), SRF (synchronous reference frame).
I. INTRODUCTION
Power Quality in electric networks is one of
today’s most concerned area of electric power system.
The power quality has serious economic implication
for consumer, utilities and electrical equipment
manufacturers. The impact of power quality problem
is increasingly felt by customers-industrial,
commercial even residential. Some of the main power
quality problems are sag, swell, transient, harmonic
and flickers. Storage technologies have developed
significantly in order to meet the challenges of
practical power systems applications. Energy storage
devices provide valuable benefits to improve stability,
power quality and reliability of supply. Energy storage
appears to be beneficial to utilities since it can
decouple the instantaneous balancing between the
demand and the supply. Therefore it allows the
increased asset utilization, facilitates the penetration of
renewable sources and improves the flexibility,
reliability and efficiency of the grid. Also there are
several high performance storage technologies
available today. Energy storage devices are like
Flywheel, Pumped hydro, compressed air, Batteries
etc. At present, both hydro pump and compressed air
are commercial technologies; several test sites
incorporating batteries have been demonstrated.
SOURCES AND EFFECTS OF POWER
QUALITY PROBLEMS
In general, the single line diagram of power
distribution system is shown below:
Figure.1 Single line diagram of power supply
system
Figure.1 shows the single line diagram of Power
distribution systems, ideally, should provide their
customers with an uninterrupted flow of energy at
smooth sinusoidal voltage at the contracted magnitude
RESEARCH ARTICLE OPEN ACCESS
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level and frequency However, in practice, power
systems, especially the distribution system have
numerous nonlinear loads, which significantly affect
the quality of power supplies. As a result of the
nonlinear loads, the purity of the waveform of
supplies is lost. This ends up producing many power
quality problems.
Power Quality problems encompass a wide range
of disturbances such as voltage sags/swells, flicker,
harmonics distortion, impulse transient, and
interruptions.
Voltage dip: A voltage dip is used to refer to
short-term reduction in voltage of less than half a
second.
Voltage sag: Voltage sags can occur at any instant
of time, with amplitudes ranging from 10 – 90%
and a duration lasting for half a cycle to one
minute.
Voltage swell: Voltage swell is defined as an
increase in rms voltage or current at power
frequency for durations from 0.5 cycles to 1 min.
Voltage 'spikes', 'impulses' or 'surges': These are
terms used to describe abrupt, very brief increases
in voltage value.
Voltage transients: They are temporary,
undesirable voltages that appear on the power
supply line. Transients are high over-voltage
disturbances (up to 20KV) that last for a very
short time.
Harmonics: The fundamental frequency of the
AC electric power distribution system is 50 Hz. A
harmonic frequency is any sinusoidal frequency,
which is a multiple of the fundamental frequency.
Harmonic frequencies can be even or odd
multiples of the sinusoidal fundamental
frequency.
Flickers: Visual irritation and introduction of
many harmonic components in the supply power
and their associated ill effects.
1.1 CAUSES OF DIPS, SAGS AND SURGES
1. Rural location remote from power source
2. Unbalanced load on a three phase system
3. Switching of heavy loads
4. Long distance from a distribution transformer
with interposed loads
5. Unreliable grid systems
6. Equipments not suitable for local supply
1.2 CAUSES OF TRANSIENTS AND SPIKES
1. Lightening
2. Arc welding
3. Switching on heavy or reactive equipments such
as motors,
4. Transformers, motor, drives, etc.,
5. Electric grade switching
1.3 VOLTAGE FLUCTUATIONS
Voltage fluctuations can be described as
repetitive or random variations of the voltage
envelope due to sudden changes in the real and
reactive power drawn by a load. The characteristics of
voltage fluctuations depend on the load type and size
and the power system capacity. Figure.3.2 illustrates
an example of a fluctuating voltage waveform. The
voltage waveform exhibits variations in magnitude
due to the fluctuating nature or intermittent operation
of connected loads. The frequency of the voltage
envelope is often referred to as the flicker frequency.
Thus there are two important parameters to voltage
fluctuations, namely the frequency of fluctuation and
the magnitude of fluctuation. Both of these
components are significant in the adverse effects of
voltage fluctuations.
Figure 2: Terminal voltage waveform of
fluctuating load
In Figure.2 the voltage changes are illustrated as
being modulated in a sinusoidal manner. However, the
changes in voltage may also be rectangular or
irregular in shape. The profile of the voltage changes
will depend on the current drawn by the offending
fluctuating load. Typically, voltage changes caused by
an offending load will not be isolated to a single
customer and will propagate an attenuation form of
both upstream and downstream from the offending
load throughout the distribution system, possibly
affecting many customers.
II. EFFECTS OF VOLTAGE
FLUCTUATIONS
The foremost effect of voltage fluctuations is
lamp flicker. Lamp flicker occurs when the intensity
of the light from a lamp varies due to changes in the
magnitude of the supply voltage. This changing
intensity can create annoyance to the human eye.
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Susceptibility to irritation from lamp flicker will be
different for each individual. However, tests have
shown that generally the human eye is most sensitive
to voltage waveform modulation around a frequency
of 6-8Hz. The perceptibility of flicker is quantified
using a measure called the short-term flicker index, Pst,
which is normalized to 1.0 to represent the
conventional threshold of irritability. The
perceptibility of flicker, a measure of the potential for
annoyance, can be plotted on a curve of the change in
relative voltage magnitude versus the frequency of the
voltage changes. Figure.3.3 illustrates the approximate
human eye perceptibility with regard to rectangular
modulated flicker noting that around the 6-8Hz region.
Fluctuations as small as 0.3% are regarded as
perceptible as changes of larger magnitudes at much
lower frequencies [1]. Figure.3.3 is often referred to as
the flicker curve and represents a Pst value of 1.0 for
various frequencies of rectangular voltage fluctuations.
Although regular rectangular voltage variations are
uncommon in practice they provide the basis for the
flicker curve, defining the threshold of irritability for
the average observer. It is worth noting that the flicker
curve is based on measurements completed using a
60W incandescent light bulb. This is used as a
benchmark measurement; however the perceptibility
of lamp flicker will vary depending on the size and
type of lamp used.
Figure3: Flicker curve for rectangular
modulation frequencies
Voltage fluctuations on the public low voltage
power system are required to be within accepted
tolerances specified in the standards. In general the
acceptable region of voltage fluctuations falls below
the flicker curve illustrated in Fig.3. Voltage
fluctuations may also cause spurious tripping of relays;
interfere with communication equipment; and trip out
electronic equipment. Severe fluctuations in some
cases may not allow other loads to be started due to
the reduction in the supply voltage. Additionally,
induction motors that operate at maximum torque may
stall if voltage fluctuations are of significant
magnitude.
III. Improvement Of Voltage Profile Using
DVR
One of the major problems dealt here is the
power sag. To improve the power quality, custom
power devices are used. The device considered in this
work is DVR. In this project, different voltage
injection schemes for Dynamic Voltage Restorers
(DVRs) are analysed with particular focus on a new
method used to minimize the rating of the voltage
source converter (VSC) used in DVR. This project
presents simulation of DVR system using
MATLAB/SIMILINK.
Among the power quality problems (sags, swells,
harmonics…) voltage sags are the most severe
disturbances. In order to overcome these problems the
concept of custom power devices is introduced
recently. One of those devices is the DVR, which is
the most efficient and effective modern custom power
device used in power distribution networks. DVR is a
recently proposed series connected solid state device
that injects voltage into the system in order to regulate
the load side voltage. It is normally installed in a
distribution system between the supply and the critical
load feeder at the point of common coupling (PCC).
Other than voltage sags and swells compensation,
DVR can also add other features like: line voltage
harmonics compensation, reduction of transients in
voltage and fault current limitations and the location
of DVR.
Note that the DVR is capable of generating or
absorbing reactive power but the active power
injection of the device must be provided by an
external energy source or energy storage system. The
response time of DVR is very short and is limited by
the power electronic devices and the voltage sag
detection time. The prediction response time is about
25millisecond, and which is much less than some of
the traditional methods of voltage correction such as
tap-changing transformer.
3.2 BASIC CONFIGURE RATION OF DVR
The schematic diagram of DVR is shown in
Figure.4.1 and the general configure ration of the
DVR consists of
1. An Injection/ Booster transformer
2. A Harmonic filter
3. Storage Devices
4. A Voltage Source Converter (VSC)
5. DC charging circuit
6. A Control and Protection system
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Figure.4: Schematic diagram of DVR
3.2.1 Injection/ Booster transformer
The Injection / Booster transformer is a specially
designed transformer that attempts to limit the
coupling of noise and transient energy from the
primary side to the secondary side. Its main tasks are
It connects the DVR to the distribution network
via the HV-windings and transforms and couples
the injected compensating voltages generated by
the voltage source converters to the incoming
supply voltage.
In addition, the Injection / Booster transformer
serves the purpose of isolating the load from the
system (VSC and control mechanism).
3.2.2 Harmonic Filter
The main task of harmonic filter is to keep the
harmonic voltage content generated by the VSC to the
permissible level.
3.2.3 Voltage Source Converter
A VSC is a power electronic system consists of a
storage device and switching devices, which can
generate a sinusoidal voltage at any required
frequency, magnitude, and phase angle. In the DVR
application, the VSC is used to temporarily replace the
supply voltage or to generate the part of the supply
voltage which is missing.
The purpose of storage devices is to supply the
necessary energy to the VSC via a dc link for the
generation of injected voltages. The different kinds of
energy storage devices are Superconductive magnetic
energy storage (SMES), batteries and capacitance.
3.2.4 DC Charging Circuit
The dc charging circuit has two main tasks
The first task is to charge the energy source after
a sag compensation event.
The second task is to maintain dc link voltage at
the nominal dc link voltage.
3.2.5 Control and protection
The control mechanism of the general configure
ration typically consists of hardware with
programmable logic. All protective functions of the
DVR should be implemented in the software.
Differential current protection of the transformer, or
short circuit current on the customer load side are only
two examples of many protection functions possibility.
IV. EQUATIONS RELATED TO DVR
Equivalent circuit diagram of DVR is shown in
Figure.5. The system impedance Zth depends on the
fault level of the load bus.
Figure.5: Equivalent circuit diagram of DVR
When the system voltage (Vth) drops, the DVR
injects a series voltage VDVR through the injection
transformer so that the desired load voltage magnitude
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VL can be maintained. The series injected voltage of
the DVR can be written as
VDVR=VL+ZTHIL-VTH (3.1)
Where
VL: The desired load voltage magnitude
ZTH: The load impedance
IL: The load current
VTH: The system voltage during fault condition
The load current IL is given by,
IL= (3.2)
When VL is considered as a reference equation can be
rewritten as,
VDVR<0=VL<0+ZTH (3.3)
α, β, δ are angles of VDVR ZTH VTH respectively and θ
is Load power angle
(3.4)
The complex power injection of the DVR can be
written as,
SDVR=VDVRIL* (3.5)
It requires the injection of only reactive power
and the DVR itself is capable of generating the
reactive power.
V. DVR WITH PI CONTROLLER
A DVR is a custom power device used to correct
the voltage sag by injecting voltage as well power into
the system. The mitigation capacity of DVR is
generally influenced by the maximum load; power
factor and maximum voltage dip to be compensated.
The DVR is to transfer the voltage which is required
for the compensation capacity of a particular DVR
depends on the maximum voltage injection capability
and the active power that can be supplied by the DVR.
When DVR’S voltage distribution system occurs,
active power or energy should be injected from DVR
to the distribution system.
Figure.6 shows a Controller is required to control
or to operate DVR during the fault conditions only.
Load voltage is sensed and passed through a sequence
analysers. The magnitude of the actual voltage is
computed with reference voltage (Vref). Pulse Width
Modulated (PWM) control system is applied for
inverter switching so as to generate a three phase 50
HZ sinusoidal voltages at the load terminals.
Chopping frequency is in the range of a few KHz.
Figure.6: Schematic of a typical PI controller.
VI. SYNCHRONOUS REFERENCE
FRAME THEORY
The synchronous reference frame strategy uses
co-ordinate transformations to generate the current
reference [11]. The abc quantities can be converted
into d-q quantities using the Equations (1) to (4).
(1)
Where,
(2)
(3)
(4)
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A study on the issues in power grid and its
compensation system has been discussed. DVR is a
suitable compensation device for the system.
VII. CONTROL ALGORITHM
The flow chart of the control algorithm for
inverter is shown in Fig. 4.1. If a three phase voltage
of the grid is balanced, a transformation into d-q
frame will result in dc quantities. The dq0
transformation technique is used to give the
information of the depth (d) and phase shift (q) of
voltage sag with start and end time. The V0, Vd and
Vq are obtained as V0 =1/a (Va+ Vb+ Vc) = 0, Vd
=2/3 [Va sin ωt + Vb sin (ωt - 2π/3) + Vc sin (ωt
+2π/3 )], Vq =2/3 [Va cos ωt + Vb cos (ωt -2π/3 ) +
Vc cos (ωt +2π/3 )].
Figure 7: Flowchart of control algorithm for inverter
After conversion of the three phase voltage Va,
Vb and Vc into two constant voltages Vd and Vq the
three phase system is simplified for voltage
calculations and the system can be easily controlled.
Actual values of wind generator voltage (VLa, VLb,
VLc) in d–q coordinates are calculated (VLd and
VLq) using the above equations. θ is calculated using
three phase Phase Locked Loop. The synchronous
reference frame variables, Vd and Vq are compared
with the d and q components of the reference voltage
which is the nominal grid voltage and the error
voltages in Vd and Vq are obtained. The
supercapacitor dc voltage is compared with the
reference dc voltage and the error voltage is given to
a PI controller. The output of the PI controller is
compared with the reference current and again given
to another PI controller. The output of this PI
controller is then added with the error Vd component.
These d-q quantities are then converted to α-β
quantities. These signals are used as reference voltage
for the SVPWM generator, which provides firing
signals for the inverter switches.
Thus the injection voltage is generated according
to the difference between the wind generator voltage
and the reference supply voltage and is applied to the
VSI. The output of the inverter is filtered using an LC
filter and is then given to the grid through a series
transformer. A super capacitor is used as energy
storage device for the inverter. This gives a faster
response than a battery and also has a longer life. The
proposed system compensates the voltage sag in the
grid system during the fault.
VIII. SIMULATIONS AND RESULTS
The simulation has been done using MATLAB/
SIMULINK and the results obtained have been
discussed in this chapter. The control algorithm has
been tested for voltage sag and swell condition.
Figure no:8 which represents the simulink model with
three phase RLC series load.
Figure :9 represents the subsystem for DVR which is
used to inject voltage.
Figure: 10 represents the subsystem for Synchronous
reference frame theory used for the control process.
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Figure.8 : simulink model with series load
Figure.9: subsystem for DVR
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Figure.10: Subsystem for SRF
.Figure.11: Output for voltage sag
From this the figure 11,12 which represents the
output for voltage sag and voltage swell.
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Figure. 12: Output for voltage swell
Figure.13: Simulink model with wind generator
In this figure .13 which shows the simulink model
which consists of wind generator as a load. Figure .14
represents the subsystem for wind generator used to
measure the speed of the generator. Figure .15,16
which shows the Output for voltage sag and voltage
swell.
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Figure.14: Subsystem for wind generator
Figure.15: Output for voltage sag
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Figure.16: Output for voltage swell
IX. CONCLUSION
In this project, a fast and cost efficient Dynamic
Voltage Restorer (DVR) comprising of a discrete PI
controller is an emerging device used for power
quality improvement. This new technique
incorporates a module as a DC voltage source to
mitigate voltage variations and enhances power
quality of a distribution system.
Simulations are carried out by using
MATLAB/SIMULINK. Simulation results
demonstrated good performance. The simulation
result shows the fault clearing using DVR. It is clear
from the result that, the increase in unbalance load
voltage is decreased by using DVR. Thus the
proposed system eliminates the problem of voltage
dip, swell and other voltage disturbances problem in
industrial distribution system.
ACKNOWLEDGEMENT
The authors would like to thank the Principal, the
HOD and to all faculty members of EEE Department,
Friends who have render their valuable help in
completing this paper successful.
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