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
Enhancement of Power Quality Using the Combination of Thyristor-Controlled Re...IJERD Editor
This paper proposes the combined system of a thyristor – controlled reactor (TCR) and the shunt active filter for harmonic and reactive power compensation. The tuned passive filter and the TCR form a shunt passive filter to compensate the reactive power. The power system harmonics are a menace to electric power system with disastrous consequences. The line current harmonics can cause increase in losses, instability and voltage distortion. Shunt active filters have been used near harmonic producing loads or at the point of common coupling to block the current harmonics. With the diverse application involving reactive power together with harmonic compensation, passive filters are found suitable. The total harmonic distortion and compensation current are carried out in MATLAB using SIMULINK. With the increase in non-linear loads in power system, more and more filters are required. The active filters are designed and analysed to improve the power quality
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.
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
Enhancement of Power Quality Using the Combination of Thyristor-Controlled Re...IJERD Editor
This paper proposes the combined system of a thyristor – controlled reactor (TCR) and the shunt active filter for harmonic and reactive power compensation. The tuned passive filter and the TCR form a shunt passive filter to compensate the reactive power. The power system harmonics are a menace to electric power system with disastrous consequences. The line current harmonics can cause increase in losses, instability and voltage distortion. Shunt active filters have been used near harmonic producing loads or at the point of common coupling to block the current harmonics. With the diverse application involving reactive power together with harmonic compensation, passive filters are found suitable. The total harmonic distortion and compensation current are carried out in MATLAB using SIMULINK. With the increase in non-linear loads in power system, more and more filters are required. The active filters are designed and analysed to improve the power quality
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.
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
Power Quality Improvement using Passive shunt filters, TCR and TSC combinationIJERA Editor
In this thesis Power Quality Improvement is examined using Passive shunt filter, TCR and TSC combination. Today’s electric power systems are connected to many non-linear loads. The characteristics of these non-linear loads inevitably change the sinusoidal nature of the a.c. power current, resulting in the flow of harmonic current in the a.c. power system. Use of shunt passive filters in the reduction of harmonics offers the advantages of more simplicity, high reliability, high efficiency and low cost. The uncontrolled ac-dc converter suffers from operating problems of poor power factor, injection of harmonics into the ac mains, variations in dc link voltage of input ac supply, equipment overheating due to harmonic current absorption, voltage distortion due to the voltage drop caused by harmonic currents flowing through system impedances etc.The combinations of passive filters with TCR and TSC are designed and analyzed to improve the power quality at ac mains. This scheme has resulted in improved power quality with overall reduced rating of passive components used in front end ac-dc converters with R-L load.
A Three Level Single Stage PFC Converter for Variable Power Applicationspaperpublications3
Abstract: AC/DC power converters are required to operate with high power factor (PF) and low total harmonic distortion (THD) for improved grid quality and full capacity utilization of the transmission lines. Passive PF correction (PFC) circuits consist of inductive and capacitive filters followed by a diode bridge. They provide the simplest way of achieving high PF with high efficiency; however, they require low line frequency filters which are bulky and heavy. This work presents a new single stage three level isolated AC/DC PFC converter for high DC link voltage low-power applications achieved through an effective integration of AC/DC and DC/DC stages where all of the switches are shared between two operations. With the converter and switching scheme, input current shaping and output voltage regulation can be achieved simultaneously without introducing additional switches or switching actions. Due to the flexible DC link voltage structure, high power factor can be achieved at high line voltage. The performance of the single stage PFC converter is simulated in MATLAB/SIMULINK environment.
Keywords: Power Factor (PF), DC Link Voltage, Power Factor Correction Circuits (PFC).
Title: A Three Level Single Stage PFC Converter for Variable Power Applications
Author: Litty Joseph, Prof. Neetha John, Prof. Emmanuel Babu P
ISSN 2349-7815
International Journal of Recent Research in Electrical and Electronics Engineering (IJRREEE)
Paper Publications
Total Harmonic Distortion Analysis of Multilevel Inverter Fed To Induction Mo...IJERA Editor
This paper presents the control of a multilevel inverter supplied by a Photovoltaic (PV) panel and a batteries
bank. It is well known that the power quality of multilevel inverter signals depends on their number of levels.
However, the question that arises is whether there is a limit beyond which it is not necessary to increase the
number of level. This question is addressed in this paper. Three, nine and fifteen-level converters are studied.
The harmonics content of the output signals are analyzed. A simplified Pulse Width Modulation (SPWM)
method for a multilevel inverter that supplied an induction motor is developed. The controller equations are such
that the SPWM pulses are generated automatically for any number of levels. The effectiveness of the propose
method is evaluated in simulation. Matlab®/ Simulink is used to implement the control algorithm and simulate
the system.
Here's an old but quite clever approach app note from Microchip on utilizing microcontroller I/O's to handle multiple display and switches with only few pins. This application note demonstrates the capability of the PIC16C71
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
Power Quality Improvement using Passive shunt filters, TCR and TSC combinationIJERA Editor
In this thesis Power Quality Improvement is examined using Passive shunt filter, TCR and TSC combination. Today’s electric power systems are connected to many non-linear loads. The characteristics of these non-linear loads inevitably change the sinusoidal nature of the a.c. power current, resulting in the flow of harmonic current in the a.c. power system. Use of shunt passive filters in the reduction of harmonics offers the advantages of more simplicity, high reliability, high efficiency and low cost. The uncontrolled ac-dc converter suffers from operating problems of poor power factor, injection of harmonics into the ac mains, variations in dc link voltage of input ac supply, equipment overheating due to harmonic current absorption, voltage distortion due to the voltage drop caused by harmonic currents flowing through system impedances etc.The combinations of passive filters with TCR and TSC are designed and analyzed to improve the power quality at ac mains. This scheme has resulted in improved power quality with overall reduced rating of passive components used in front end ac-dc converters with R-L load.
A Three Level Single Stage PFC Converter for Variable Power Applicationspaperpublications3
Abstract: AC/DC power converters are required to operate with high power factor (PF) and low total harmonic distortion (THD) for improved grid quality and full capacity utilization of the transmission lines. Passive PF correction (PFC) circuits consist of inductive and capacitive filters followed by a diode bridge. They provide the simplest way of achieving high PF with high efficiency; however, they require low line frequency filters which are bulky and heavy. This work presents a new single stage three level isolated AC/DC PFC converter for high DC link voltage low-power applications achieved through an effective integration of AC/DC and DC/DC stages where all of the switches are shared between two operations. With the converter and switching scheme, input current shaping and output voltage regulation can be achieved simultaneously without introducing additional switches or switching actions. Due to the flexible DC link voltage structure, high power factor can be achieved at high line voltage. The performance of the single stage PFC converter is simulated in MATLAB/SIMULINK environment.
Keywords: Power Factor (PF), DC Link Voltage, Power Factor Correction Circuits (PFC).
Title: A Three Level Single Stage PFC Converter for Variable Power Applications
Author: Litty Joseph, Prof. Neetha John, Prof. Emmanuel Babu P
ISSN 2349-7815
International Journal of Recent Research in Electrical and Electronics Engineering (IJRREEE)
Paper Publications
Total Harmonic Distortion Analysis of Multilevel Inverter Fed To Induction Mo...IJERA Editor
This paper presents the control of a multilevel inverter supplied by a Photovoltaic (PV) panel and a batteries
bank. It is well known that the power quality of multilevel inverter signals depends on their number of levels.
However, the question that arises is whether there is a limit beyond which it is not necessary to increase the
number of level. This question is addressed in this paper. Three, nine and fifteen-level converters are studied.
The harmonics content of the output signals are analyzed. A simplified Pulse Width Modulation (SPWM)
method for a multilevel inverter that supplied an induction motor is developed. The controller equations are such
that the SPWM pulses are generated automatically for any number of levels. The effectiveness of the propose
method is evaluated in simulation. Matlab®/ Simulink is used to implement the control algorithm and simulate
the system.
Here's an old but quite clever approach app note from Microchip on utilizing microcontroller I/O's to handle multiple display and switches with only few pins. This application note demonstrates the capability of the PIC16C71
Dopow LED Indicator& Buzzer
1. Various Colors: Red, Green, Yellow, White, Blue.
2. Diverse Design, Variety chances to choose.
3. Semi-Permanet, It's economical.
4. Great Appearance:It's contributes to apply in electronic equipments widely.
5. Visible in Various Sides: A several of projected designs.
Transformer types core, shell, toroidal. steps to design a EI core type transformer by calculating tongue width, stack height etc and two examples are given
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Electromechanical relays are an excellent solution to separate electronic control circuitry and power circuitry. Electromechanical relays are not the best choice in high frequency switching applications and do have a limited life due to wear on the contacts inside the relay. When used in the a proper application, the electromechanical relay provides safe and reliable integration between power circuits and control circuits.
ZVZCS Based High Frequency Link Grid Connected SVM Applied Three Phase Three ...IAES-IJPEDS
This article proposes a newly proposed highly effective Zero Voltage and Zero Current switching based Front end converter with a High Frequency Transformer with a Three Phase Three Level Diode Clamped Inverter in photovoltaic applications. The switching scheme is implemented in MATLAB/ Simulink condition. ZVZCS condition is achieved. This type of converter shows high efficiency and very negligible switching loss. Finally ZVZCS based High Frequency Link Diode Clamped Inverter is connected to Grid. An MCI optimized Current controller is used with SVM switching technique. In This article, responses with three types of controllers (I, PI, PID) have been examined and compared. Simulation results show the effectiveness, and validity of this technique.
Soft Switched Multi-Output Flyback Converter with Voltage DoublerIJPEDS-IAES
A novel multi-output voltage doubler circuit with resonant switching
technique is proposed in this paper. The resonant topology in the primary
side of the flyback transformer switches the device either at zero voltage or
current thus optimizing the switching devices by mitigating the losses. The
voltage doubler circuit introduced in the load side increases the voltage by
twice the value thereby increasing the load power and density. The proposed
Multi-output Isolated Converter removes the need for mutiple SMPS units
for a particular application. This reduces the size and weight of the
converters considerably leading to a greater payload. This paper aims at
optimizing the proposed converter with some design changes. The results
obtained from the hardware prototype are given in a comprehensive manner
for a 3.5W converter operating at output voltages of 5V and 3.3V at 50 kHz
switching frequency. The converter output is regulated with the PI controller
designed with SG3523 IC. The effects of load and line regulation for ±20%
variations are analyzed in detail.
Modified Bidirectional Converter with Current Fed InverterIJPEDS-IAES
A bidirectional dc-dc converter with multiple outputs are concatenated with a
high frequency current source parallel resonant push pull inverter is
presented in this paper. The two outputs are added together and it is taken as
the input source for the inverter. The current source parallel resonant push
pull inverter implemented here with high frequency applications like
induction heating, Fluorescent lighting, Digital signal processing sonar. This
paper proposes a simple photovoltaic power system consists of a
bidirectional converter and a current fed inverter for regulating the load
variations. Solar power is used as the input source for the system. Simulation
of the proposed system is carried out in PSIM software and experimentally
verified the results.
Electrical Discharge Machining Flyback Converter using UC3842 Current Mode PW...IJPEDS-IAES
This paper presents a current mode Pulse Width Modulation (PWM) controlled Flyback converter using UC3842 for Electrical Discharge Machining current generator control circuit. Circuit simplicity and high efficiency can be achieved by a Flyback converter with current mode PWM controller. The behaviors of the system's operation is analyzed and discussed by varying the load resistance. Matlab sofware is used to simulate the Flyback converter where a prototype has been built and tested to verify its performance.
Analysis of Modulation Strategies for Two-Stage Interleaved Voltage Source In...IJARBEST JOURNAL
This paper deals with the investigation of interleaved voltage source inverter for
photovoltaic applications. This topology focuses on the reduction of inductor current ripple
content, total harmonic distortion (THD) of the proposed topology. In addition, the filter size is
reduced when compared to single-stage voltage source inverter. The design of filter for the
proposed topology is highlighted. The paper discusses the different modulation strategies for the
proposed topology with different values of modulation index. A comparison made between the
different strategies is reported. And comparison is done between single-stage and two-stage
voltage source inverter with chosen modulation strategies. Simulation studies of the proposed VSI
are carried out in MATLAB/SIMULINK.
Simulation of D-STATCOM to study Voltage Stability in Distribution systemijsrd.com
This paper presents the simulation of D-statcom to understand the improvement of voltage stability [1] of distribution system. The power circuits of the D-STATCOM and distribution networks are made up of simpower system blocks, while the control circuits made with the simulink blocks The STATCOM is applied to regulate transmission voltage to allow greater power flow in a voltage limited transmission network, in the same manner as a static var compensator (SVC), the STATCOM has further potential by giving an inherently faster response and greater output to a system with depressed voltage and offers improved quality of supply. The main applications of the STATCOM are; Distribution STATCOM (D-STATCOM) exhibits high speed control of reactive power to provide voltage stabilization and other type of system control. The DSTATCOM protects the utility transmission or distribution system from voltage sag and /or flicker caused by rapidly varying reactive current demand. During the transient conditions the D-STATCOM provides leading or lagging reactive power to active system stability, power factor correction and load balancing.
Design & Implementation of Zero Voltage Switching Buck ConverterIJERA Editor
Zero voltage switching (ZVS) buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. In Zero voltage switching converter, turn on & turn off of a switch occurs at zero voltage that results in lower switching losses. In this converter soft switching is achieved by using resonant components. The optimal values of resonant components are determined by using electric functions derived from circuit configuration. This type of soft switched resonant converter offers very low electromagnetic interference (EMI).This study presents the circuit configuration with least components to realize highly efficient zero voltage switching resonant converter. It’s feasibility is confirmed with the developed proto type model and experimental results are verified.
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.
Matlab Simulink Model of Sinusoidal PWM For Three-Phase Voltage Source Inverterijtsrd
This paper concentrates on modeling and simulation of single phase inverter as a frequency changer modulated by sinusoidal Pulse Width Modulation PWM technique. An inverter is a circuit that converts DC sources to AC sources. To judge the quality of voltage produced by a PWM inverter, a detailed harmonic analysis of the voltage waveform is done. Pulse width modulated PWM inverters are among the most used power-electronic circuits in practical applications. These inverters are capable of producing ac voltages of variable magnitude as well as variable frequency with less harmonic distortion. The model is executed utilizing MATLAB Simulink software with the SimPower System Block Set using PC simulation. MATLAB Simulink is a successful instrument to examine a PWM inverter. Major reasons for using MATLAB are Faster reaction, accessibility of different simulation devices and the nonappearance of joining issues. In this paper, Insulated Gate Bipolar Transistor IGBT is used as switching power device. IGBT is ideal since it high switching speed and also high input impedance. Finally a MATLAB SIMULINK model for the SPWM is presented. Various simulation results are also included. Asha Durafe "Matlab/Simulink Model of Sinusoidal PWM For Three-Phase Voltage Source Inverter" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-6 , October 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18614.pdf
Simulation and Comparison of DVR and DSTATCOM Used for voltage sag mitigation...paperpublications3
Abstract: Power Quality problem in a system leads to various disturbances such as voltage fluctuations, transients and waveform distortions that results in a mis-operation or a failure of end user equipment. There are different types of custom power devices like Distribution Static Compensator (D-STATCOM) and Dynamic Voltage Restorer (DVR) which can effectively use for mitigation of different type of power quality problems. This paper describes the technique of correcting the supply voltage sag distributed system and also describes performance comparison are presented between DVR and DSTATCOM to know how both the devices successfully been applied to power system for regulating system voltage effectively. DSTATCOM and DVR both of them based on VSI principle. A DVR is a series compensation device which injects a voltage in series with system and a DSTATCOM is a shunt compensation device which injects a current into the system to correct the power quality problems. This paper presents a power system operation with PI controller with abc to dq0 convertor approach. Total Harmonics Distortion (THD) is also calculated for the system with and without compensation. Results are presented to assess the performance of devices as a potential custom power solution. Improve dynamic voltage control and thus increase system load ability. This paper presents modeling and simulation of DVR & DSTATCOM in MATLAB/Simulink.
Power Quality Improvement Using Cascaded H-Bridge Multilevel Inverter Based D...IJERA Editor
Cascaded multilevel configuration of the inverter has the advantage of its simplicity and modularity over the
configurations of the diode-clamped and flying capacitor multilevel inverters. This paper presents a threephase,
five-level and seven level cascaded multilevel voltage source inverter based active filter for power line
conditioning to improve power quality in the distribution network. The DSTATCOM helps to improve the
power factor and eliminate the Total Harmonics Distortion (THD) drawn from a Non-Liner Diode Rectifier
Load (NLDRL). The compensation process is based on concept of p-q theory. A CHB Inverter is considered for
shunt compensation of a 11 kV distribution system. Finally a level shifted PWM (LSPWM) and phase shifted
PWM (PSPWM) techniques are adopted to investigate the performance of CHB Inverter. The results are
obtained through Matlab/Simulink software package.
This work presents investigation of passive filter performance on three-phase inverter with 180° conduction mode. The simulation model of the inverter is developed by using MATLAB/Simulink. The power circuit used Insulated Gate Bipolar Transistor (IGBT) as switching device. The inverter is controlled by using bipolar Sinusoidal Pulse Width Modulation (SPWM) technique. The IGBT was set to 25 kHz for switching frequency (fs). Three types of passive filters which are LC, RC and PI filters are used to investigate the ability to remove the unwanted signal that occurred on the inverter. The result is analyzed based on the performances of output filter in term of Total Harmonic Distortion in voltage (THDv), current (THDi), shape of output voltage and current. The THD must be less than 5% at rated inverter output voltage or current by referring to IEC 61727 Standard. The passive filter is modeled in MATLAB/Simulink environment to study the characteristics and performance of the filters.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Monitoring Java Application Security with JDK Tools and JFR Events
E044043336
1. B. Nookesh et al Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 4( Version 4), April 2014, pp.33-36
www.ijera.com 33 | P a g e
Voltage Sag Mitigation Using Pulse Width Modulation Switched
Autotransformer through Matlab Simulation
P. Shyam Kiran*, B. Nookesh#1
, M. Naga Bhavani#2
, B. Anil Kumar#3
, G. Mani
Kumar#
*Assistant Professor, EEE Dept, Lendi Institute of Engineering & Technology, Vizianagaram (Dt.), Andahra
Pradesh, India.
#
U.G Students & Department of Electrical & Electronics Engineering, Lendi Institute of Engineering &
Technology, Affiliated to JNTUK University, Jonnada (v), Denkada (m), Vizianagaram (Dt.), Andahra Pradesh
, India.
Abstract
In this paper, a new voltage sag compensator for critical loads in electrical distribution system discussed. The
proposed scheme employs a Pulse width modulation ac-ac converter along with a auto transformer. During a
disturbance such as voltage sag, the proposed scheme supplies the missing voltage and helps in maintaining the
rated voltage at the terminals of the critical load. Under normal condition the approach work in bypass mode
and delivering utility power directly to load. The proposed system has less number of switching devices and has
good compensating capability in comparison to commonly used compensators. Simulation analysis of three-
phase compensator is performed in MATLAB/SIMULINK and performance analysis of the system is presented
for various levels of sag and swell.
Keywords:- Power Quality, Voltage Sag, PWM Switched Autotransformer, IGBTs, Sag Mitigation.
I. INTRODUCTION
Power Quality issues have become an
increasing concern with an increased usage of critical
and sensitive loads in industrial processes
Disturbances such as voltage sags and swells, short
duration interruptions, harmonics and transients
may disrupt the processes and lead to considerable
economic loss [3,4]
. A power distribution system is
similar to a vast network of rivers. It is important to
remove any system faults so that the rest of the power
distribution service is not interrupted or damaged.
When a fault occurs somewhere in a power
distribution system, the voltage is effected throughout
the power system. Among the various power quality
problems, the majority of events are associated with
either a voltage sag or a voltage swell, and the often
cause serious power interruptions. A voltage sag
condition implies that the voltage on one or more
phases drops below the specified tolerance for a short
period of time [2,5].
A new mitigation device for voltage sag is
proposed in [1]
using PWM-switched autotransformer.
The performance of the compensator for various sag
conditions is presented. This paper presents modeling
and analysis of PWM switched autotransformer that
can compensate during voltage sag and swell
conditions. The proposed scheme has less number of
switching devices and has good compensating
capability in comparison to commonly used
compensators. Simulation and analysis of 3-
phasecompensator is performed in
MATLAB/SIMULINK and performance of the new
mitigation conditions of sag and swell.
II. PROPOSED SYSTEM
CONFIGURATION
The proposed device for mitigating voltage
sag and swell in the system consists of a PWM
switched power electronic device connected to an
autotransformer in series with the load.
Fig.1. Voltage sag mitigating device with PWM
switched autotransformer
Fig.1 shows the single phase circuit configuration
of the mitigating device and the control circuit logic used in
the system. It consists of a single PWM insulated gate
bipolar transistor (IGBT) switch in a bridge configuration,
RESEARCH ARTICLE OPEN ACCESS
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a thyristor bypass switch, an autotransformer, and voltage
controller.
III. PRINCIPLE OF OPERATION
To maintain the load voltage constant an IGBT
is used as power electronic device to inject the error
voltage into the line. Four power diodes (D1 to D4)
connected to IGBT switch (SW) controls the direction of
power flow and connected in ac voltage controller
configuration with a suitable control circuit maintains
constant rms load voltage. In this scheme sinusoidal PWM
pulse technique is used. RMS value of the load voltage VL
is calculated and compared with the reference rms voltage
Vref.
During normal condition the power flow is
through the anti parallel thyristors. Output filters
containing a main capacitor filter and a notch filter are used at
the output side to filter out the switching noise and reduce
harmonics. During this normal condition, VL = Vref and
the error voltage Verr is zero. The gate pulses are blocked to
IGBT.
Due to sudden increase or decrease in the
load or due to voltage sag or swell occurs. The
supply voltage VS and hence VL decreases. When
the sensing circuit detects an error voltage Verr
greater than 10% of the normal voltage the voltage
controller acts immediately to switch off the
thyristors. Voltage Verr applied to the pi controller
gives the phase angle δ. The control voltage given in
Eq. (1) is constructed at power frequency f = 50Hz.
V control = ma × sin (ωt + δ). (1)
Where ma is the modulation index.
The phase angle δ is dependent on the
percentage of disturbance and hence controls the
magnitude of Vcontrol. This control voltage is then
compared with the triangular voltage Vtri to generate
the PWM pulses VG which are applied to the IGBT
to regulate the output voltage. Hence the IGBT
switch operates only during voltage sag or swells
condition and regulates the output voltage according
to the PWM duty-cycle. To suppress the over voltage
when the switches are turned off, RC snubber circuits
are connected across the IGBT and thyristor.
IV. VOLTAGE SAG COMPENSATION
The ac converter topology is employed for
realizing the voltage sag compensator. This paper
considers the voltage mitigation scheme that use only
one shunt type PWM switch[1] for output voltage
control as shown in Fig. 2. The autotransformer
shown in Fig. 2 is used in the proposed system to
boost the input voltage instead of a two winding
transformer. Switch IGBT is on the primary side of
the autotransformer.
The voltage and current distribution in the
autotransformer is shown in Fig. 3. It does not
provide electrical isolation between primary side and
secondary side but has advantages of high efficiency
with small volume. The compensator considered is a
shunt type as the control voltage developed is injected
in shunt. The relationships of the autotransformer
voltage and current are expressed in Eq. (2)
𝑉𝐿/𝑉P= a = 𝐼𝑆/𝐼𝐿 = (N1 + 𝑁2)/𝑁1 (2)
where a is the turns ratio; VP=Primary voltage; VL
=Secondary voltage; I1, I2 =primary and secondary
currents, respectively; IS =Source current; IL =Load current.
Fig2. Voltage sag/sell mitigating device
Fig3.Voltage and current relations in an
autotransformer
The autotransformer in Fig.3 does not offer electrical
isolation between primary side and secondary side
but has advantages of high efficiency with small
volume. An transformer with N1: N2 = 1 : 1 ratio is
used as an autotransformer to boost the voltage on the
load side when sag is detected. With this the device
can mitigate up to 50% voltage sag during the sag
period. As the of that VL = 2VP and IS=2IL.The
switch is located in the autotransformer’s primary
side and the magnitude of the switch current equals
the load current. The voltage cross the switch in the
off-state is equal to the magnitude of the input
voltage. When sag is detected by the voltage
controller, IGBT switched ON and is regulated by the
PWM pulses. The primary voltage VP is such that the
load voltage on the secondary of autotransformer is
the desired rms voltage.
Fig 4. MATLAB/SIMULINK model of a 3-phase
used for voltage sag studies
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V. RIPPLE FILTER DESIGN
The output voltage VP given by the IGBT is
the pulse containing fundamental component of 50
Hz and harmonics at switching frequency. Hence
there is a necessity to design a suitable ripple filter at
the output of the IGBT to obtain the load voltage
THD within the limits. A notch filter to remove the
harmonics and a low pass filter for the fundamental
component are used as shown in Fig. 1. Capacitor Cr1
in combination with source inductance and leakage
inductance form the low pass filter. The notch filter
designed with a center frequency of PWM switching
frequency by using a series LC filter. A resistor may
be added to limit the current. The impedance of the
filter is given by Eq.(3)
|z|= 𝑅2 + (𝜔𝐿 𝑟 −
1
𝜔 𝐶 𝑟2
)2 (3)
where R, Lr and Cr2 are the notch filter resistance,
inductance and capacitances respectively. The
resonant frequency of the notch filter is tuned to the
PWM switching frequency. The capacitor is designed
by considering its kVA to be 25% of the system
kVA. Capacitor value (Ctotal) thus obtained is divided
into Cr1 and Cr2 equally. The notch filter designed for
switching frequency resonance condition is
capacitive in nature for frequencies less than its
resonance frequency. Hence at fundamental
frequency it is capacitive of value Cr2 and is in
parallel with Cr1 resulting to Ctotal.
VI. SIMULATION ANALYSIS AND
RESULTS
Simulation analysis is performed on a three-
phase, 115/11 kV, 100 MVA, 50 Hz system to study
the performance of the PWM switched
autotransformer in mitigating the voltage sag and
swell disturbances. The MATLAB/SIMULINK
model of the system used for analysis is shown in
Fig.4. An RL load is considered as a sensitive load,
which is to be supplied at constant voltage. Tab.1
shows the system parameter specifications used for
simulation.
Fig.5.Model of 3-ϕPWM switched autotransformer
Under normal condition, the power flow is
through the anti parallel SCRs and the gate pulses are
inhibited to IGBT. The load voltage and current are
same as supply voltage and current. When a
disturbance occurs, an error voltage which is the
difference between the reference rms voltage and the
load rms voltage is generated. The PI controller thus
gives the angle δ. Control voltage at fundamental
frequency (50 Hz) is generated and compared with
the carrier frequency triangular wave of carrier
frequency 1.5 kHz. The PWM pulses now drive the
IGBT switch. The simulation modeling of PWM
switched autotransformer used as mitigating device
along
Table 1. System parameters used for simulation
Fig 6.The simulation waveforms of the load voltage
for voltage sag of 27%
Fig 7.Simulation waveform for voltage sag formation
during 0.1 second
Fig 8.Simulation waveform for per phase error
voltage1 in RMS value
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Fig 9.Simulationwaveform for per phase error
voltage 3 in RMS value
with its control circuit is shown in Fig. 5.
The autotransformer rating in each phase is 6.35/6.35
kV (as line voltage is 11 kV) with 1:1 turns ratio. The
effective voltage available at the primary of
autotransformer is such that the load voltage is
maintained at desired rms value (6.35 kV or 1 pu).
Voltage sag is created during the simulation by
sudden application of heavy load of P=10MW and
Q=50Mvar for a period of 0.1 sec(5cycles) from t1 =
0.1 sec to t2 = 0.2 sec Figs.(6 to 10) shows the
simulation waveforms of the load voltage for voltage
sag of 27%.
Fig 10.Simulation waveform for voltage sag
mitigated using PWM switched autotransformer
VII. CONCLUSION
A new voltage sag compensator based on
PWM switched autotransformer has been presented
in this paper. Control circuit based on rms voltage
reference is discussed. The proposed technique could
identify the disturbance and capable of mitigating the
disturbance by maintaining the load voltage at
desired magnitude within limits. The proposed
technique is simple and only one IGBT switch per
phase is required. Hence the system is more simple
and economical compared to commonly used DVR or
STATCOM. Simulation analysis is performed for
27% voltage sag for three phase system and
simulation results verify that the proposed device is
effective in compensating the voltage sag
disturbances.
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