https://jst.org.in/index.html
Our journal has envision the collaborative future we're creating—one where engineering, management, science, and mathematics harmonize to shape a world defined by innovation and progress. Numbers tell stories, and in the world of research and development, mathematics is the universal language.
Comparative of Conventional and Intelligence Controller based Hybrid Generati...IJERD Editor
Harmonic pollution of the power supply system has risen significantly in recent years due primarily
to an increase of non-linear loads connected to the utility through residential, commercial and industrial
customers. This paper, proposed a solution to eliminate the harmonics introduced by the nonlinear loads in
steady and in transients. It presents a predictive current control strategy for achieving maximum benefits from
these grid-interfacing inverters implementing conventional DC link controller and intelligence controller, when
installed in 3-phase 4-leg voltage source inverter (VSI). The inverter is controlled to perform as a multi-function
device by incorporating active power filter functionality. The use of a four-leg voltage-source inverter allows
the compensation of current harmonic components, as well as unbalanced current generated by three-phase
nonlinear loads. Renewable energy resources (RES) are being increasingly connected in distribution systems
utilizing power electronic converters. The compensation performance of the proposed active power filter and the
associated hybrid PV/Wind system generation scheme with new control scheme is demonstrated to improve the
power quality features is simulated using MATLAB/SIMULINK.
report of Improvement of the Electric Power Quality Using Series Active and S...Vikram Rawani
The increase of nonlinear loads due to the proliferation of electronic equipment causes power quality in the power system to deteriorate. Harmonic current drawn from a supply by the nonlinear load results in the distortion of the supply voltage waveform at the point of common coupling (PCC) due to the source impedance. Both distorted current and voltage may cause end-user equipment to malfunction, conductors to overheat and may reduce the efficiency and life expectancy of the equipment connected at the PCC.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Simulation of Shunt Active Power Filter Based on p q Theoryijtsrd
This paper introduces design and simulation of a low cost shunt active power filter, which allows dynamic power factor correction and harmonic compensation for a nonlinear load. One of the most important features of the shunt active filter system proposed is its versatility over a variety of different conditions. The active filter controller is based on the Instantaneous power theory p q theory , which monitors the load current and injects equal amplitude and opposite phase compensation currents to neutralise load current harmonics. The application of the positive sequence voltage detector from within the active filter controller is the key component of the system. The positive sequence voltage detector gives incredible versatility to the application of the active filter, because it can be installed and compensate for load current harmonics even when the input voltage is highly distorted and unbalanced. The controller algorithm is carried out using MATLAB Simulink. Dr. G. Madasamy "Simulation of Shunt Active Power Filter Based on p-q Theory" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-1 , February 2023, URL: https://www.ijtsrd.com/papers/ijtsrd52791.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/52791/simulation-of-shunt-active-power-filter-based-on-pq-theory/dr-g-madasamy
Mitigation of the Harmonics under Reactive Power Compensation by SHPF-TCR Usi...IJERA Editor
In this paper, a combined system of a thyristor-controlled reactor (TCR) and a shunt hybrid power filter
(SHPF)has been designed by MATLAB/SIMULINK approach for harmonic and reactive power compensation.
The quality of the power is effected by many factors like harmonic contamination, due to the increment of nonlinear
loads, sag and swell due to the switching of the loads etc. Also control schemes based on PI and Fuzzy
logic controllers have been proposed to mitigate the harmonics and neutral current . The proposed methodology
not only reduces the complexity but also offers simplicity to implement and increases reliability of the system.
These control strategies also help in achieving a low cost highly effective control. The performance is also
observed under influence of utility side disturbances such as harmonics, flicker and spikes with Non-Linear and
Reactive Loads with different control strategies.
Harmonic Voltage Distortions in Power Systems Due to Non Linear LoadsIJAPEJOURNAL
Harmonics are found to have deleterious effects on power system equipments including transformers, capacitor banks, rotating machines, switchgears and protective relays. Transformers, motors and switchgears may experience increased losses and excessive heating. Shunt filters are effective in minimizing voltage distortions. This paper describes the voltage distortions generated by non linear loads. The harmonic specifications such as harmonic factor, characteristic harmonic and non-characteristic harmonic are considered while explaining the paper. ‘MiPower’ software is used to compute the harmonic distortions in a sample power system. Accurate harmonic models are established for a non linear load. To reduce the harmonic voltages impressed upon specific parts of the sample power system, passive filters are installed at two buses. With the implementation of a passive filter at the bus with non linear load, the harmonics are greatly reduced. For the specified power system, at all the buses the total harmonic distortion has been evaluated.
Power Quality Improvement by UPQC based on Voltage Source ConvertersIJRST Journal
In modern power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipment’s are nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. These problems are partially solved with the help of LC passive filters. However, this kind of filter cannot solve random variation in the load current wave form and voltage wave form. Active filters can resolve this problem. However, the cost of active filters is high. They are difficult to implement in large scale. Additionally, they also present lower efficiency than shunt passive filters. One of the many solutions is the use of a combined system of shunt and active series filters like Unified Power Quality Conditioner (UPQC) which aims at achieving a low cost under highly effective control. The UPQC device combines a shunt active filter together with a series active filter in a back-to-back configuration, to simultaneously compensate the supply voltage and the load current or to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The control strategies are modeled using MATLAB/SIMULINK. The performance is also observed under influence of utility side disturbances such as harmonics and voltage sags. The simulation results are compared without and with UPQC for the verification of results.
Comparative of Conventional and Intelligence Controller based Hybrid Generati...IJERD Editor
Harmonic pollution of the power supply system has risen significantly in recent years due primarily
to an increase of non-linear loads connected to the utility through residential, commercial and industrial
customers. This paper, proposed a solution to eliminate the harmonics introduced by the nonlinear loads in
steady and in transients. It presents a predictive current control strategy for achieving maximum benefits from
these grid-interfacing inverters implementing conventional DC link controller and intelligence controller, when
installed in 3-phase 4-leg voltage source inverter (VSI). The inverter is controlled to perform as a multi-function
device by incorporating active power filter functionality. The use of a four-leg voltage-source inverter allows
the compensation of current harmonic components, as well as unbalanced current generated by three-phase
nonlinear loads. Renewable energy resources (RES) are being increasingly connected in distribution systems
utilizing power electronic converters. The compensation performance of the proposed active power filter and the
associated hybrid PV/Wind system generation scheme with new control scheme is demonstrated to improve the
power quality features is simulated using MATLAB/SIMULINK.
report of Improvement of the Electric Power Quality Using Series Active and S...Vikram Rawani
The increase of nonlinear loads due to the proliferation of electronic equipment causes power quality in the power system to deteriorate. Harmonic current drawn from a supply by the nonlinear load results in the distortion of the supply voltage waveform at the point of common coupling (PCC) due to the source impedance. Both distorted current and voltage may cause end-user equipment to malfunction, conductors to overheat and may reduce the efficiency and life expectancy of the equipment connected at the PCC.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Simulation of Shunt Active Power Filter Based on p q Theoryijtsrd
This paper introduces design and simulation of a low cost shunt active power filter, which allows dynamic power factor correction and harmonic compensation for a nonlinear load. One of the most important features of the shunt active filter system proposed is its versatility over a variety of different conditions. The active filter controller is based on the Instantaneous power theory p q theory , which monitors the load current and injects equal amplitude and opposite phase compensation currents to neutralise load current harmonics. The application of the positive sequence voltage detector from within the active filter controller is the key component of the system. The positive sequence voltage detector gives incredible versatility to the application of the active filter, because it can be installed and compensate for load current harmonics even when the input voltage is highly distorted and unbalanced. The controller algorithm is carried out using MATLAB Simulink. Dr. G. Madasamy "Simulation of Shunt Active Power Filter Based on p-q Theory" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-1 , February 2023, URL: https://www.ijtsrd.com/papers/ijtsrd52791.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/52791/simulation-of-shunt-active-power-filter-based-on-pq-theory/dr-g-madasamy
Mitigation of the Harmonics under Reactive Power Compensation by SHPF-TCR Usi...IJERA Editor
In this paper, a combined system of a thyristor-controlled reactor (TCR) and a shunt hybrid power filter
(SHPF)has been designed by MATLAB/SIMULINK approach for harmonic and reactive power compensation.
The quality of the power is effected by many factors like harmonic contamination, due to the increment of nonlinear
loads, sag and swell due to the switching of the loads etc. Also control schemes based on PI and Fuzzy
logic controllers have been proposed to mitigate the harmonics and neutral current . The proposed methodology
not only reduces the complexity but also offers simplicity to implement and increases reliability of the system.
These control strategies also help in achieving a low cost highly effective control. The performance is also
observed under influence of utility side disturbances such as harmonics, flicker and spikes with Non-Linear and
Reactive Loads with different control strategies.
Harmonic Voltage Distortions in Power Systems Due to Non Linear LoadsIJAPEJOURNAL
Harmonics are found to have deleterious effects on power system equipments including transformers, capacitor banks, rotating machines, switchgears and protective relays. Transformers, motors and switchgears may experience increased losses and excessive heating. Shunt filters are effective in minimizing voltage distortions. This paper describes the voltage distortions generated by non linear loads. The harmonic specifications such as harmonic factor, characteristic harmonic and non-characteristic harmonic are considered while explaining the paper. ‘MiPower’ software is used to compute the harmonic distortions in a sample power system. Accurate harmonic models are established for a non linear load. To reduce the harmonic voltages impressed upon specific parts of the sample power system, passive filters are installed at two buses. With the implementation of a passive filter at the bus with non linear load, the harmonics are greatly reduced. For the specified power system, at all the buses the total harmonic distortion has been evaluated.
Power Quality Improvement by UPQC based on Voltage Source ConvertersIJRST Journal
In modern power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipment’s are nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. These problems are partially solved with the help of LC passive filters. However, this kind of filter cannot solve random variation in the load current wave form and voltage wave form. Active filters can resolve this problem. However, the cost of active filters is high. They are difficult to implement in large scale. Additionally, they also present lower efficiency than shunt passive filters. One of the many solutions is the use of a combined system of shunt and active series filters like Unified Power Quality Conditioner (UPQC) which aims at achieving a low cost under highly effective control. The UPQC device combines a shunt active filter together with a series active filter in a back-to-back configuration, to simultaneously compensate the supply voltage and the load current or to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The control strategies are modeled using MATLAB/SIMULINK. The performance is also observed under influence of utility side disturbances such as harmonics and voltage sags. The simulation results are compared without and with UPQC for the verification of results.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The Shunt Active Power Filter to Compensate Reactive Power and Harmonics with...ijtsrd
In this paper is to study the denomination Power quality and large refers to maintaining a proximal sinusoidal power distribution bus voltage at rated magnitude and frequency. This is mainly affected by the generation of harmonics. Even though electronic and non-linear devices are flexible, economical and energy efficient, they may degrade power quality by creating harmonic currents and consuming excessive reactive power. This paper shows the method of improving the power quality using shunt active power filter with proposed optimized PI. The proposed topic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is from hysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Its source current, compensating current and THD values are studied, then PI control strategy is applied then the differences in THD are compared. The PI feedback compensation design starts with the small signal system' transfer function. Then an optimum constant of PI for a Shunt-APF is proposed and implemented to enhance its response to compensation of harmonics of linear and non-linear loads. The obtained results have demonstrated the ability to compensate the current harmonics effectively under distorted source conditions. The fluctuation in the dc bus voltage of the filter depends on the compensation speed of the outer loop that regulates the dc bus voltage. The proposed shunt active filter model uses balanced linear and non-linear load works successfully lowers the THD within IEEE norms and satisfactorily works to compensate current harmonics. The model is made in MATLAB SIMULINK and successfully reduces the harmonic in the source current. Mr. Amit Kumar Rajan | Dr. E Vijay Kumar"The Shunt Active Power Filter to Compensate Reactive Power and Harmonics with optimized PI controller in a 3 Phase 3 Wire Distribution System" 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/ijtsrd18196.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18196/the-shunt-active-power-filter-to-compensate-reactive-power-and-harmonics-with-optimized-pi-controller-in-a-3-phase-3-wire-distribution-system/mr-amit-kumar-rajan
Harmonic enhancement in microgrid with applications on sensitive loadsIJECEIAES
Power quality issues are an important and growing problem in microgrid. There are two reasons; the more active consumer is participating in the power sector, the use of renewable energy which having a great impact on voltage variation. This paper discusses power quality disturbance and especially harmonic distortion issues in microgrid, and suggests a solution to maintain the operation of the distribution system within power quality standard. To protect sensitive loads from harmonics produced by the grid and by renewable energy sources, passive harmonic filter has been proposed in this paper. The electrical system of a nuclear research reactor as sensitive loads is designed by using Electrical Transient Analyzer Program (ETAP) software. The results show these technical issues are presented with their influence on electrical voltage and harmonic specter.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Power Flow Control In A Transmission Line Using Unified Power Flow ControllerIJMER
This paper concentrates on FACT device UPFC which is used for powerflow control in the
transmission side. With the growing demand of electricity, it is not possible to erect new lines to face the
situation. Flexible AC Transmission System (FACTS) makes use of the thyristor controlled devices and optimally
utilizes the existing transmission network. One of such device is Unified Power Flow Controller (UPFC) on
which the emphasis is given in this present work. Real, reactive power, and voltage balance of the unified
power-flow control (UPFC) system is analyzed. A novel coordination controller is proposed for the UPFC.
The basic control method is such that the shunt converter controls the transmission line reactive power
flow and the dc-link voltage. The series converter controls the real power flow in the transmission line and
the UPFC bus voltages. Experimental works have been conducted to verify the effectiveness of the
UPFC in power flow control in the transmission line. The simulation model was done in
MATLAB/SIMULINK platform.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
https://jst.org.in/index.html
Our journal has academic journals form a crucial nexus. Educators leverage the latest research findings to enrich their teaching methodologies, ensuring that students are exposed to the most current and relevant information. Simultaneously, these educators contribute to the body of knowledge through their own research, creating a perpetual cycle of growth.
https://ijaast.com/index.html
Our journal has open-access nature of IJAAST fosters global collaboration. Researchers from diverse geographical locations can engage with and build upon each other's work, transcending borders to collectively address the challenges and opportunities in agricultural science and technology.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The Shunt Active Power Filter to Compensate Reactive Power and Harmonics with...ijtsrd
In this paper is to study the denomination Power quality and large refers to maintaining a proximal sinusoidal power distribution bus voltage at rated magnitude and frequency. This is mainly affected by the generation of harmonics. Even though electronic and non-linear devices are flexible, economical and energy efficient, they may degrade power quality by creating harmonic currents and consuming excessive reactive power. This paper shows the method of improving the power quality using shunt active power filter with proposed optimized PI. The proposed topic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is from hysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Its source current, compensating current and THD values are studied, then PI control strategy is applied then the differences in THD are compared. The PI feedback compensation design starts with the small signal system' transfer function. Then an optimum constant of PI for a Shunt-APF is proposed and implemented to enhance its response to compensation of harmonics of linear and non-linear loads. The obtained results have demonstrated the ability to compensate the current harmonics effectively under distorted source conditions. The fluctuation in the dc bus voltage of the filter depends on the compensation speed of the outer loop that regulates the dc bus voltage. The proposed shunt active filter model uses balanced linear and non-linear load works successfully lowers the THD within IEEE norms and satisfactorily works to compensate current harmonics. The model is made in MATLAB SIMULINK and successfully reduces the harmonic in the source current. Mr. Amit Kumar Rajan | Dr. E Vijay Kumar"The Shunt Active Power Filter to Compensate Reactive Power and Harmonics with optimized PI controller in a 3 Phase 3 Wire Distribution System" 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/ijtsrd18196.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18196/the-shunt-active-power-filter-to-compensate-reactive-power-and-harmonics-with-optimized-pi-controller-in-a-3-phase-3-wire-distribution-system/mr-amit-kumar-rajan
Harmonic enhancement in microgrid with applications on sensitive loadsIJECEIAES
Power quality issues are an important and growing problem in microgrid. There are two reasons; the more active consumer is participating in the power sector, the use of renewable energy which having a great impact on voltage variation. This paper discusses power quality disturbance and especially harmonic distortion issues in microgrid, and suggests a solution to maintain the operation of the distribution system within power quality standard. To protect sensitive loads from harmonics produced by the grid and by renewable energy sources, passive harmonic filter has been proposed in this paper. The electrical system of a nuclear research reactor as sensitive loads is designed by using Electrical Transient Analyzer Program (ETAP) software. The results show these technical issues are presented with their influence on electrical voltage and harmonic specter.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Power Flow Control In A Transmission Line Using Unified Power Flow ControllerIJMER
This paper concentrates on FACT device UPFC which is used for powerflow control in the
transmission side. With the growing demand of electricity, it is not possible to erect new lines to face the
situation. Flexible AC Transmission System (FACTS) makes use of the thyristor controlled devices and optimally
utilizes the existing transmission network. One of such device is Unified Power Flow Controller (UPFC) on
which the emphasis is given in this present work. Real, reactive power, and voltage balance of the unified
power-flow control (UPFC) system is analyzed. A novel coordination controller is proposed for the UPFC.
The basic control method is such that the shunt converter controls the transmission line reactive power
flow and the dc-link voltage. The series converter controls the real power flow in the transmission line and
the UPFC bus voltages. Experimental works have been conducted to verify the effectiveness of the
UPFC in power flow control in the transmission line. The simulation model was done in
MATLAB/SIMULINK platform.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
https://jst.org.in/index.html
Our journal has academic journals form a crucial nexus. Educators leverage the latest research findings to enrich their teaching methodologies, ensuring that students are exposed to the most current and relevant information. Simultaneously, these educators contribute to the body of knowledge through their own research, creating a perpetual cycle of growth.
https://ijaast.com/index.html
Our journal has open-access nature of IJAAST fosters global collaboration. Researchers from diverse geographical locations can engage with and build upon each other's work, transcending borders to collectively address the challenges and opportunities in agricultural science and technology.
https://jst.org.in/index.html
Our journal has serves as a beacon for scholars and practitioners alike, delving into the intricacies of next-generation technologies that promise to reshape the world. From artificial intelligence and renewable energy to advanced materials and beyond, we are at the forefront of engineering's evolution.
https://ijaast.com/index.html
Our journal has increasing flow of scholarly research articles finds a dedicated channel in IJAAST. By offering a consistent platform, the journal facilitates the seamless flow of knowledge, contributing to the intellectual growth of the agricultural science and technology community.
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Our journal has transcends traditional boundaries by embracing a multi-disciplinary approach. The journal serves as a melting pot for diverse research areas within agricultural science and technology, ensuring a holistic exploration of the subject.
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Our journal has foster a sense of community among researchers, scholars, and academics. They provide a space for intellectual exchange, allowing scholars to engage with each other's work, provide constructive feedback, and build upon existing knowledge.
https://ijaast.com/index.html
Our journal has we providing a robust platform for scholarly discourse, IJAAST contributes to the nurturing of future innovations. The journal's role in disseminating novel ideas, methodologies, and findings serves as a catalyst for pushing the boundaries of what is possible in agricultural research.
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Our journal has stands as a beacon of excellence in the realm of agricultural research. With its multi-disciplinary focus, commitment to peer-reviewed excellence, and open-access philosophy, IJAAST is not merely a journal; it is a dynamic hub driving the evolution of agricultural science and technology.
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Our journal has dynamic realm of agricultural science and technology, staying abreast of the latest research findings is crucial for professionals, scholars, and enthusiasts alike. IJAAST transcends traditional boundaries by embracing a multi-disciplinary approach.
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Our Journal has stand as pillars, providing a crucial medium for the advancement and dissemination of research results. This blog post explores the pivotal role these journals play in supporting high-level learning, teaching, and research.
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Our journal has a academic journals is the peer-review process. Before an article is published, it undergoes rigorous scrutiny by experts in the field. This ensures the quality and validity of the research, maintaining a high standard of academic integrity.
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Our Journal has a exploring partnerships and initiatives to provide training and resources to researchers, reviewers, and editors on issues related to JEDI in statistics. Journal has implemented rigorous editorial practices to ensure that published research adheres to JEDI principles.
Our journal has a academic journals form a crucial nexus. Educators leverage the latest research findings to enrich their teaching methodologies, ensuring that students are exposed to the most current and relevant information. Simultaneously, these educators contribute to the body of knowledge through their own research, creating a perpetual cycle of growth.
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Our journal has academic and professional communities fosters collaboration and knowledge sharing. When all voices are heard and respected, it strengthens the collective capabilities of the statistical community.
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Our journal has academic journals are not mere repositories of information; they are dynamic entities that breathe life into the academic world. They provide a stage for the drama of ideas, where researchers, educators, and learners converge to push the boundaries of knowledge.
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Our journal Research Knowledge and experience exchange increases social, economic and cultural growth, higher education, career and commercial prospects relevant to members of the department and its surrounding area. And it's journal publishes research papers in the fields of science and technology such as Astronomy and astrophysics, Chemistry, Earth and atmospheric sciences, Physics, Biology in general.
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Our Journal has we strive to minimize barriers to access and participation, ensuring that opportunities within the statistical community are available to all, regardless of background. This includes addressing issues such as language barriers, geographical disparities, and financial constraints that may limit access to statistical education and resources.
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Our journal has stands as a beacon of excellence in the field, fostering a culture of high-quality research and unwavering commitment to academic integrity. As research continues to push the boundaries of what's possible, peer review remains an essential tool in ensuring that we continue to progress responsibly and ethically in the realms of science and technology.
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Our journal has Numbers tell stories, and in the world of research and development, mathematics is the universal language. Join us as we explore the elegant equations and mathematical models that underpin technological advancements and scientific breakthroughs.
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Our journal has digital transformation, effective management strategies are crucial. Our pages unfold discussions on navigating the complexities of modern business landscapes, strategic decision-making, and adaptive leadership—essential elements for success in the 21st century.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
2024.06.01 Introducing a competency framework for languag learning materials ...
research on journaling
1. Journal of Science and Technology
ISSN: 2456-5660 Volume 06, Issue 01, Jan-February 2021
www.jst.org.in DOI: https://doi.org/10.46243/jst.2020.v6.i1.pp21-45
Published by: Longman Publishers 21 | Page
Fuzzy Controller Based Power Quality Improvement Using VLLMS
Based Shunt Active Power Filter
Dhavala Pranusha1
, Thumuganti Ramya2
1
(Dept of EEE, Vignan Institute of Technology and Science, Hyderabad)
1
Corresponding Author: 29pranusha@gmail.com
To Cite this Article
Dhavala Pranusha and Thumuganti Ramya, “Fuzzy Controller Based Power Quality Improvement Using VLLMS
Based Shunt Active Power Filter”, Journal of Science and Technology, Vol. 06, Issue 01, Jan-February 2021,
pp21-45
Article Info
Received: 18-07-2020 Revised: 15-10-2020 Accepted: 04-11-2020 Published: 18-11-2020
Abstract: The power quality problem in the power system is increased with the use of non-linear devices. Due to
the use of non-linear devices like power electronic converters, there is an increase in harmonic content in the source
current. Due to this there is an increase in the losses, instability and poor voltage waveform. To mitigate the
harmonics and provide the reactive power compensation, we use filters. There are different filters used in the power
system. Passive filters provide limited compensation, so active filters can be used for variable compensation. In this
work, a shunt active filter has been made adaptive using a Variable Leaky Least Mean Square (VLLMS) based
controller. Proposed adaptive controller can be able to compensate for harmonic currents, power factor and
nonlinear load unbalance. DC capacitor voltage has been regulated at a desired level using a PI controller and a
self-charging circuit technique. But, this scheme as two disadvantages such as, tuning issues of current controller
pre-requisites the traditional PI controller, which is controlled by intelligent based Hybrid-Fuzzy-Logic controller
for achieving good performance features. The design concept of proposed intelligent Hybrid-Fuzzy controller for
shunt active filter has been verified through simulation analysis and results are presented with proper comparisons.
Keywords: APF, harmonics, neural network, power quality, Variable Leaky Least Mean Square (VLLMS).
_____________________________________________________________________________________
I. Introduction
Early equipment was designed to withstand disturbances such as lightning, short circuits, and sudden
overloads without extra expenditure. Current power electronics (PE) prices would be much higher if the equipment
was designed with the same robustness. Pollution has been introduced into power systems by nonlinear loads such
as transformers and saturated coils; however, perturbation rate has never reached the present levels. Due to its
nonlinear characteristics and fast switching, PE creates most of the pollution issues. Most of the pollution issues are
created due to the nonlinear characteristics and fast switching of PE. Approximately 10% to 20% of today’s energy
is processed by PE; the percentage is estimated to reach 50% to 60% by the year 2010, due mainly to the fast growth
of PE capability. A race is currently taking place between increasing PE pollution and sensitivity, on the one hand,
and the new PE-based corrective devices, which have the ability to attenuate the issues created by PE, on the other
hand.
Increase in such non-linearity causes different undesirable features like low system efficiency and poor power
factor. It also causes disturbance to other consumers and interference in nearby communication networks. The effect
of such non-linearity may become sizeable over the next few years. Hence it is very important to overcome these
undesirable features.
Modern day power systems are complicated networks with hundreds of generating stations and load centers being
interconnected through power transmission lines. An electric power system has three separate components - power
generation, power transmission and power distribution.
Almost all power generation takes place at generating stations that may contain quality nature of our power. The
basic structure of a power system is shown in Fig 1.1. It contains a generating plant, a transmission system, a sub-
2. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
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transmission system and a distribution system. These subsystems are interconnected through transformers T], T2
and T3. Let us consider some typical voltage levels to understand the functioning of the power system.
Fig.1.1 An Typical power system network
It can therefore be seen that there are various stages between the point of power generation to the stage when
electric power is delivered to the end users. The correct operation of all components of a power system is absolutely
critical for a reliable power delivery. There are many issues involved here such as the maintenance of power
apparatus and system, the stability of the system operation, the operation of power distribution system, faults etc.
Even a few years back, the main concern of consumers of electricity was the reliability of supply. Here we define
reliability as the continuity of electric supply. It is however not only reliability that the consumers want these days,
quality too is very important to them.
Transmission lines are exposed to the forces of nature. Furthermore, each transmission line has its load ability
limit that is often determined by either stability considerations or by thermal limits. Even though the power quality
problem is a distribution side problem, transmission lines often have an impact on the quality of power supplied. It is
however to be noted that while most problems associated with transmission systems arise due to the forces of nature
or due to the interconnection of power systems, individual customers are responsible for a more substantial fraction
of the problems of power distribution systems.
II. Related Work
Fang Z. Peng and Donald J. Adams “Harmonic Sources and Filtering Approaches”
Traditionally, nonlinear loads have been represented as a current source because their current waveforms are
distorted from pure sine-waves at fundamental frequency. A typical harmonic source isa phase-controlled thyristor
rectifier having a sufficient dc inductance to produce a non-pulsating dc current. Accordingly, parallel (or shunt)
passive and parallel active filters are commonly applied to nonlinear loads to mitigate harmonics. The principle of
the parallel passive filter is to provide a low-impedance shunt branch to the load's harmonic current, thus reducing
harmonic current flowing into the source.
J. C. Das,” Passive Filters—Potentialities and Limitations”
Most of the distribution systems require reactive power compensation to improve the power factor, save demand
charges, or to release additional active power from existing equipment or for voltage support, i.e., the reactive power
support required to arrest the voltage drop on loss of a plant generator. The nonlinear loads are increasing, i.e., pulp
and paper mill distribution systems invariably have adjustable-speed drive (ASD) systems, which may form a
considerable percentage of overall plant load. When power capacitors are used for reactive power compensation, it
becomes necessary to turn them in to filters to escape harmonic resonance problems with one of the load-generated
harmonics It is not uncommon to apply passive filters in the mega Var range and filters totaling some tens of mega
var in a large installation may be required. An improvement in power factor from 0.85 to 0.9 for a system demand of
100 MVA requires approximately 10 Mvar of compensation. Passive filters have been extensively used to
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simultaneously meet one or more objectives and also meet the requirements of IEEE Std. 519 with respect to total
demand distortion (TDD) at the point of common coupling (PCC). Passive filters have also been extensively used in
HVDC systems, arc-furnace installations, and static var compensators (SVCs) to name a few more applications.
Herbert L. Ginn, IIIand Leszek S. Czarnecki “An Optimization Based Method for Selection of Resonant
Harmonic Filter Branch Parameters”
Resonant harmonic filters (RHFs) are effective devices for reducing supply current harmonics when only
those load generated harmonics for which they are tuned are present. Other current harmonics as well as supply
voltage harmonics may reduce the effectiveness of RHFs in harmonic suppression. To counter such reductions in
effectiveness, an optimization based method for selection of filter branch parameters is developed for the
conventional RHF. It takes into consideration the interaction of the filter with the distribution system and provides
filter parameters that give the maximum effectiveness with respect to harmonic suppression. Due to the presence of
harmonic generating loads (HGLs) in distribution systems, resonant harmonic filters very often operate in the
presence of distribution voltage harmonics as well as load current harmonics other than those to which the filter is
tuned. Some of the voltage and current harmonics could be amplified by the filter resonance with the distribution
system inductance, as seen from the bus where the RHF is installed. Moreover, the filter as seen from the
distribution system has very low impedance at tuned frequencies. Consequently, with the increase of distortion of
the distribution voltage and the amount of non-characteristic harmonics in the load current, the effectiveness of the
filter in reducing distortion of the bus voltage and the supply current declines. Harmonic amplification caused by the
filter resonance with the distribution system inductance depends on frequencies of this resonance and can be reduced
by appropriate selection of the filter parameters. Harmful effects due to the filter’s low impedance at the tuned
frequencies can be reduced, by detuning the filter from frequencies of characteristic harmonics. Unfortunately, this
detuning reduces the attenuation of the load current harmonics.
José Antenor Pomilioand Sigmar Maurer Deckmann” Characterization and Compensation of Harmonics and
Reactive Power of Residential and Commercial Loads”
Depending on the nonlinear load characteristics, the usual representation of nonlinear loads as a simple
combination of harmonic current sources may greatly simplify the analyses of their effects on the overall system
under similar conditions where distortion has been derived. However, additional conclusions may not be reliable if
any modification is introduced in the circuit, such as the connection of a filter or a change in the loading condition.
This certainly limits the usefulness of linear models to study nonlinear processes.
H. Akagi “Active Harmonic Filters”
Active filters are typically used with diode/thyristor rectifiers, electric arc furnaces, etc. Their use in electric
power utilities, industry, office buildings, water supply utilities, and transportation is increasing as cost reductions in
power semiconductor devices and signal processing devices make use of these filters more economically attractive.
In addition to harmonic filtering, active harmonic filters are used for damping, isolation, termination, power-factor
correction, voltage regulation, load balancing, and voltage-flicker reduction, Compared to passive filters, active
harmonic filters provide superior filtering performance and more flexible operation, and they are more compact.
However, both the cost of active filters and their operating loss are currently slightly higher than for passive filters.
Unlike passive filters, active filters provide the capability of controlling reactive power for inductive loads. While
active filters for power conditioning are now commercially available, Akagi believes that manufacturers should
strive to improve the filtering performance and efficiency of these units and to reduce costs so they can better
compete with traditional passive filters. As an example of a pure active filter, Akagi describes a filter that draws
compensating current from an ac supply to cancel out harmonic currents produced by the load. A passive high-pass
filter on the ac side of the active filter eliminates switching ripples, but plays no role in canceling out dominant fifth-
and seventh-harmonic currents produced by the load. The active filter control circuit uses digital signal processors,
field-programmable gate arrays, and A/D converters for digital signal processing, operational and isolation
amplifiers for analog signal processing, and Hall-effect current/voltage sensors.
III. Problem Statement
Over the past few years, rapid increase in the use of non- linear loads causes many power quality issues, like
high current harmonics, low power factor and excessive neutral current. The increased harmonics, reactive power
and un- balance cause increase in voltage distortion, linlosses and instability when harmonic current travel upstream
and produce drop across the line impedance, which leads distortion in power system. Usually, passive filters are
used for suppression of harmonics but their applications are limited to fixed amount of compensation. Passive filters
are also not capable in providing solutions in presence of unbalance and variable reactive power compensation.
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Another disadvantage with passive filter is the problem of resonance which amplifies current of certain harmonic
frequencies. The solution to above mentioned problem can be realized using a shunt active power filter
IV. Shunt Active Power Filters
This class of filters constitutes the most important and widely used filter configuration in industrial process. It is
connected in parallel to the main power circuit as shown in Fig.4.2. The concept of the shunt active power filter is
based on harmonic cancellation through the act of injecting equal and opposite harmonic currents into the supply
line by means of solid-state converter circuits. Normally these filters are connected in parallel with the load, and
carry only a fraction of the fundamental current. Furthermore, they can be designed to provide compensation for all
of the system non-linear ties at the point of common coupling (PCC) under distorted and non-distorted supply.
Fig. 4.1 Schematic Diagram of Shunt active power filter
These filters have disadvantages of injection of switching frequency harmonics in the system. Due to the need
of high switching frequency fully gate controlled devices these filters are limited to low and medium power range
only. Shunt active power filter compensate current harmonics by injecting equal-but-opposite harmonic
compensating current. In this case the shunt active power filter operates as a current source injecting the harmonic
components generated by the load but phase shifted by 180o
. This principle is applicable to any type of load
considered a harmonic source. Moreover, with an appropriate control scheme, the active power filter can also
compensate the load power factor. In this way, the power distribution system sees the non linear load and the active
power filter as an ideal resistor. The current compensation characteristic of the shunt active power filter is shown in
Fig.4.1.
V. Active Power Filter Driven By VLMMS Control Technique
A. Active Power Filter
The current source iLis used to model the instantaneous current of the nonlinear load that can be represented by
Where iL1 is the peak value of the fundamental component and iLn is the peak value of the harmonic component. L1
and Ln are the phase angles of the fundamental and the harmoniccomponents. Fig. 1 shows the circuit for shunt APF.
Voltage source v represents the instantaneous supply voltage at the PCC with is as its instantaneous supply current. The
injection current of the shunt active filter is denoted by iinj. The first order low-pass filter in series with the VSI output is
represented by inductor Lsh with resistor Rshas the inverter losses. Vdc /2 denote the voltage of each capacitorunit.In (1)
above, the instantaneous current of the nonlinear load is expanded into 3 terms.The first term is the load instantaneous
fundamental phase current iL1,pwhich is always in phase with the supply voltage. The second term iL1,pis the load
instantaneous fundamental quadrature current which is always 90° out of phase
withthesupplyvoltage.ThethirdtermiLnistheloadinstantaneous harmoniccurrents.FromFig.5.1,itcanbeshownthat
5. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
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dc
(5.2)
In order to have is that is almost in phase with v and at thesame timeconsistsonlyofthefundamentalcomponent,from(2)
(5.3)
The dc voltage of each capacitor Vdc/2 is also measured and passed to the self-charging circuit to regulate to its reference
voltage level V* /2. The output signal from the self-charging circuit idc together with iL1,qand iLn will form the reference
injection current of the adaptive shunt active filter i*.
Fig.5.1. Block Diagram of Proposed APF Compensation Scheme
B. Proposed VLLMS Algorithm
Here a VLLMS algorithm is used for extraction of fundamental active component of current from load current. For that, signal
can be modeled as
(5.4)
(4) can be rewritten in parametric form as follows
(5.5)
(5.6)
The vector of unknown parameter
(5.7)
The VLLMS algorithm is applied to estimate the state. The algorithm minimizes the square of the error recursively by altering
the unknown parameter Xk a teachsamplinginstant using(8)given below
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(5.8)
Where the error signal is
(5.9)
Step size μk is varied for better convergence of the VLLMS algorithm in the presence of noise.
(5.10)
Where Rk representsthe autocorrelation of ek and ek-1. It is computed as
(5.11)
Where β is an exponential weighting parameter and 0<β <1, and λ(0 <λ <1) and γ > 0 control the convergence
time.The variable leakage factor γk can be adjusted as
(5.12)
After the updating of the vector of unknown parameter using VLLMS algorithm
(5.13)
As seen from Fig. 1, the current output of the VLLMS based fundamental extraction circuit is subtracted from the
load current. The subtracted output serves as amajor component in reference current generation. Fig. 5.2 shows the flow
chart of the active component of fundamental current extraction scheme using VLLMS algorithm.
C. Self-Charging DC-Capacitor Circuit
To regulate the dc capacitor voltage at the desired level, an additional real power has to be drawn by theadaptive shunt active
filter from the supplyside to chargethe two capacitors. The energyEstored in each capacitor can be representedas
(5.14)
If the value of the dc capacitor voltage changes from Vdc to V the change in energy is represented by
(5.15)
dc
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The charging energy delivered by the three-phase supply side to the inverter for each capacitor will be
P: additional real power required
t: charging time
Vrms: value of instantaneous supply voltage v
Idc-rms: value of the instantaneous charging current idc
: phase difference between supply voltage and charging current
(5.16)
Neglecting the switching losses in the inverter and according to the energy conservation law, the following equation
holds from (5.15) and (5.16).
(5.17)
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Fig. 5.2. Flow chart of the active fundamental current extraction scheme of VLLMS algorithm
To maintain the value of each dc capacitor voltage at the reference level V*dc / 2, Vdc / 2 is measured and
fed back to a PI controller as shown in Fig. 5.3 to manipulate V'dc/ 2. So that it can be used in (17) to compute the
required peak value of the charging current Idc from the supply side. The PI controller also helps in reducing the
steady state offset between the reference V* dc / 2 and the actual Vdc / 2. The PLL synchronizes itself with the
supply voltage of phase a i.e vaand gives three output sine-waves which are 120° out of phase with each other.
These sine waves are multiplied with Idc to obtain three phase idc. In order to force the supply side to deliver idc, a
term consisting of this idcis added to the three phase injection currents iinjthat can be represented by
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Fig.5.3. Three phase self-charging circuit with PI controller
(5.18)
Fig. 5.3 shows the schematic of three phase self-charging circuit with PI controller. The negative sign
indicates the flow of charging current into the VSI. For each phase it lags by an angle of 120°. The reference
currents calculated shows that the adaptive shunt APF injects iLnand iL1,qinto the line to compensate the harmonic
currents and the reactive power respectively, and at the same time it receives the charging current idcfrom the supply
to regulate the dc capacitor voltage. An inductor which acts a low pass filter is connected in between the filter and
the PCC to eliminate the higher order harmonics. The compensating signals along with the original injecting
currents are given to a adaptive hysteresis current controller to generate the switching pulses for the IGBTs or
switches in the inverter to produce the required currents.The block diagram representation of proposed VLLMS
controller is depicted in Fig.5.4.
(a) Block Diagram of Classical PI based VLLMS Controller
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(b) Block Diagram of Proposed Fuzzy based VLLMS Controller
(c) Block Diagram of Proposed Hybrid-Fuzzy based VLLMS Controller
Fig.5.4 Proposed VLMMS Controller
D. Adaptive Hysteresis Current Controller
Adaptive hysteresis control has been used in this work to actualize (18) at the output of VSI. The mathematical
expression derived in (18) has been used as the reference signal i* injfor the adaptive hysteresis control [22]. The
injected current iinjat the output of VSI is measured and fed back to the adaptive hysteresis control as it’s another
input. The adaptive hysteresis control will take the difference between i* injand iinjas given by
(5.19)
Taking into account the value of Δiinj, the adaptive hysteresis control will switch the IGBT of VSI as per the
expression given in (20).
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Fig.5.5. Adaptive hysteresis band current controller
(5.20)
Where HB is the hysteresis band and Swis the status of the IGBT, "1" represents on and "0" represents off. The
value of "u" shown in Fig.5.5 will be "1" if Sw= "1" and "-1" if Sw= "0". In hysteresis band current control, it has a
fixed hysteresis band due to which the switching frequency is not constant, are uneven in nature. Due to this uneven
switching frequency acoustic noise is produced. To overcome these drawbacks, an Adaptive Hysteresis Band
Current Control technique has been used which adaptively changes the hysteresis band according to system
parameters such as reference source current, source voltage, switching frequency and dc capacitor voltage, so that
the switching frequency is maintained almost constant. The hysteresis band [18] can be calculated according to the
following equation.
(5.21)
In adaptive hysteresis band current controller, since modulation frequency fc, almost remains constant, this improves
the PWM performances and APF substantially. Calculated hysteresis band using above (21), is applied to hysteresis
band current controller as shown in Fig. 5.5 for switching pulse generation to be fed back to inverter.
D. Fuzzy-Logic Controller
The Fuzzy-Logic (FL) controllers authorize based on knowledge system which includes Fuzzy member-ship
functions and Fuzzy rule-base to assimilate the human knowledge for getting subjective decisions. Some efforts
have been developed to attain improved characteristics on system performance by integrating learning mechanism
by regulating membership functions and/or rule-base system of the Fuzzy-controller [23]. The heart of the Fuzzy
controller is a knowledge system which comprises of information unit for providing linguistic variables and fuzzy
rule base. The system associated with database is used to characterize the fuzzy-rule functions and manipulation of
fuzzy data in a Fuzzy-Logic controller and the heuristic rules of the knowledge are highly influencing the controller
performance [24]. The inference mechanism decides how the fuzzy-logical operations are accomplished, and
knowledge base is simultaneously determines the output of fuzzy logic controller based on IF-THEN rules.
12. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
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(a) Fuzzy Logic Inference
(b) Block Diagram of Proposed Intelligent Controller
Fig.5.6 Design and Interface of Proposed Intelligent Controllers
The Fuzzy-Logic controller is used to furnishing the reference voltage/current signal for generation of optimal
switching states to compensator based on mamdani structure. For better enhancement a combination of proposed
Fuzzy controller with a VLLMS controller is used which increases the stability index and overall compensation
characteristics. As well as, shunt-VSI is used to compensate current harmonics, reactive power compensation, power
factor correction, etc. The error is attained from comparison of actual and reference components in terms of current
and voltage imperfections are considered as input/output for FL controller with seven linguistic variables.
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1
0
0.2
0.4
0.6
0.8
1
e
e
,
e
e
,
NL NM NS PL
PM
ZE PS
Fig. 5.7 Membership Functions of Hybrid FLC
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Table.5.1 Rule-Base of FLC
e
∆𝐞 NL NM NS ZE PS PM PL
NL NL NL NL NL NM NS ZE
NM NL NL NL NM NS ZE PS
NS NL NL NM NS ZE PS PM
ZE NL NM NS ZE PS PM PL
PS NM NS ZE PS PM PL PL
PM NS ZE PS PM PL PL PL
PL ZE NM NS EZ PS PM PL
All the membership functions of error, change in error and output are considered as triangular functions
because of simple control functions as linearity principle. These membership functions are transformed to fuzzy data
by using fuzzification process for making the favourable decisions as rule-base system and provide the output
signals and again re-transformed into general data by using centroid method of defuzzification process. The utilized
membership functions are Zero (ZE), Positive-Large (PL), Positive-Medium (PM), Positive-Small (PS) and
Negative-Large (NL), Negative -Medium (NM), Negative -Small (NS), respectively as depicted in Fig.5.7 and the
rule-base is depicted in Table.5.1.
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Fig.5.7 Over-all Schematic Diagram of Proposed Hybrid-Fuzzy Logic Controller Fed VLLMS Driven APF for PQ
Enhancement
VI. Simulation Results
The simulation analysis is conveyed by implementation of Active-Power Filter by using proposed VLLMS-
Fuzzy Logic Control scheme in a three phase power systems under several load situations with the help of system
parameters, system parameters are shown in below Table.6.1
Table.6.1. System Parameters
Parameters Values
Source Voltage 220V, 50Hz
Source Impedance 0.1+j0.282Ω
Load Impedance 2+3jΩ
DC-Link Capacitor 1500µF
VSI Filter Units R-0.001; L-10mH
PI Controller Gains Kp-0.8; Ki-0.5
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Case A: Without Presence of any Active-Power Filter
Fig.6.1 Simulation Results of Three Phase Power System under Non-Presence of APF
Fig.6.1. illustrates the various simulation outcomes of three phase power system non-presence of APF, in that
(a) Source Voltage, (b) Source Current, (c) Load Current, (d) Compensation Current, respectively. In this case load
is treated as the balanced non-linear load, due to the NL-load device the PCC currents goes to affects as a
harmonized components which is reflected the PQ concerns. Without APF compensator load parameters is always
equal to source parameters, that’s why both are stared as same.
Case B: Presence of VLLMS Driven APF under Balanced Linear Load
Fig.6.2 Simulation Results of Three Phase Power System Presence of VLLMS driven APF under Balanced
Linear Load
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Fig.6.3 THD analysis of Source Current
Fig.6.2 illustrates the various simulation outcomes of three phase power system presence of VLLMS driven
APF under balanced linear load device, in that (a) Source Voltage, (b) Source Current, (c) Load Current, (d)
Compensation Current, respectively. In this case load is treated as the balanced linear load, due to the linear-load
device the PCC currents maintains as constant and THD of source current well with in standards as depicted in
Fig.6.3, attains 2.98%.
Case C: Presence of VLLMS Driven APF under Un-Balanced Linear Load
Fig.6.4 Simulation Results of Three Phase Power System Presence of VLLMS driven APF under Un-Balanced
Linear Load
Fig.6.5 THD analysis of Source Current
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Fig.6.4 illustrates the various simulation outcomes of three phase power system presence of VLLMS driven
APF under unbalanced linear load device, in that (a) Source Voltage, (b) Source Current, (c) Load Current, (d)
Compensation Current, respectively. In this case load is treated as the unbalanced linear load, due to the unbalanced
linear-load device the PCC currents are maintains as constant due to presence of APF. But load currents are
maintained as unbalanced, as well as the APF injects compensated current to power system which regulates
balanced nature and THD of source current well with in standards as depicted in Fig.6.5, attains 2.98%.
Case D: Presence of VLLMS Driven APF under Balanced Non-Linear Load
Fig.6.6 Simulation Results of Three Phase Power System Presence of VLLMS driven APF under Balanced
Non-Linear Load
(a) THD Analysis of Source Current without Compensation (without APF)
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(b) THD Analysis of Source Current with Compensation Device (with APF)
Fig.6.7 THD Analysis of Source Current with and without APF
Fig.6.6 illustrates the various simulation outcomes of three phase system presence of APF with proposed
VLLMS control strategy under balanced non-linear load device, in that (a) Source Voltage, (b) Source Current, (c)
Load Current, (d) Compensation Current, respectively. In this case load is treated as the balanced non-linear load,
due to this load device load currents are harmonized components. But source currents maintain as harmonic-free and
well with in IEEE standards by using APF compensator by using attractive fundamental frequency based
compensation currents. The THD of source current without APF is 30.29% have more harmonic values and THD of
source current is 1.91% have low harmonics well compensated by APF and within a IEEE-519 standard’s as
depicted in Fig.6.7.
Case E: Presence of VLLMS Driven APF under Un-Balanced Non-Linear Load
Fig.6.8 Simulation Results of Three Phase Power System Presence of VLLMS driven APF under Un-Balanced
Non-Linear Load
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(c) THD Analysis of Source Current without Compensation (without APF)
(d) THD Analysis of Source Current with Compensation Device (with APF)
Fig.6.9 THD Analysis of Source Current with and without APF
Fig.6.8 illustrates the various simulation outcomes of three phase system presence of APF with proposed
VLLMS control strategy under unbalanced non-linear load device, in that (a) Source Voltage, (b) Source Current,
(c) Load Current, (d) Compensation Current, respectively. In this case load is treated as the unbalanced non-linear
load, due to this load device load currents are unbalanced and harmonized components. But source currents maintain
as harmonic-free and balanced nature well with in IEEE standards by using APF compensator by using attractive
fundamental frequency based compensation currents. The THD of source current without APF is 30.29% have more
harmonic values and THD of source current is 1.91% have low harmonics well compensated by APF and within a
IEEE-519 standard’s as depicted in Fig.6.9.
20. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
40 | Page
Case F: Presence of Fuzzy-Logic Controller based VLLMS Driven APF under Balanced Non-Linear Load
Fig.6.10 Simulation Results of Three Phase Power System Presence of Fuzzy-VLLMS driven APF under
Balanced Non-Linear Load
Fig.6.11 THD Analysis of Source Current with Compensation Device (with APF)
Fig.6.10 illustrates the various simulation outcomes of three phase system presence of APF with proposed
Fuzzy-VLLMS control strategy under balanced non-linear load device, in that (a) Source Voltage, (b) Source
Current, (c) Load Current, (d) Compensation Current, respectively. In this case load is treated as the balanced non-
linear load, due to this load device load currents are harmonized components. But source currents maintain as
harmonic-free and well with in IEEE standards by using APF compensator by using attractive fundamental
frequency based compensation currents. The THD of source current with Fuzzy-VLLMS controller driven APF is
0.42% have low harmonics well compensated by APF and within a IEEE-519 standards as depicted in Fig.6.11.
21. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
41 | Page
Case G: Presence of Hybrid-Fuzzy-Logic Controller based VLLMS Driven APF under Balanced Non-Linear
Load
Fig.6.12 Simulation Results of Three Phase Power System Presence of Hybrid-Fuzzy-VLLMS driven APF
under Balanced Non-Linear Load
Fig.6.13 THD Analysis of Source Current with Compensation Device (with APF)
Fig.6.12 illustrates the various simulation outcomes of three phase system presence of APF with proposed
Hybrid-Fuzzy VLLMS control strategy under balanced non-linear load device, in that (a) Source Voltage, (b) Source
Current, (c) Load Current, (d) Compensation Current, respectively. In this case load is treated as the balanced non-
linear load, due to this load device load currents are harmonized components. But source currents maintain as
harmonic-free and well with in IEEE standards by using APF compensator by using attractive fundamental
frequency based compensation currents. The THD of source current with Hybrid-Fuzzy VLLMS controller driven
APF is 0.29% have low harmonics well compensated by APF and within an IEEE-519 standards as depicted in
Fig.6.13.
22. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
42 | Page
Case H: Presence of Fuzzy-Logic Controller based VLLMS Driven APF under Un-Balanced Non-Linear Load
Fig.6.14Simulation Results of Three Phase Power System Presence of Fuzzy-VLLMS driven APF under Un-
Balanced Non-Linear Load
Fig.6.15 THD Analysis of Source Current with Fuzzy-VLLMS Controller
Fig.6.14 illustrates the various simulation outcomes of three phase system presence of APF with proposed Fuzzy-
VLLMS control strategy under un-balanced non-linear load device, in that (a) Source Voltage, (b) Source Current,
(c) Load Current, (d) Compensation Current, respectively. In this case load is treated as the un-balanced non-linear
load, due to this load device load currents are harmonized components and unbalanced nature. But source currents
maintain as harmonic-free and sinusoidal, balanced, well with in IEEE standards by using APF compensator by
using attractive fundamental frequency based compensation currents. The THD of source current with Fuzzy-
VLLMS controller driven APF is 0.61% have low harmonics well compensated by APF and within IEEE-519
standards as depicted in Fig.6.15.
23. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
43 | Page
Case I: Presence of Hybrid-Fuzzy-Logic Controller based VLLMS Driven APF under Un-Balanced Non-Linear
Load
Fig.6.16 Simulation Results of Three Phase Power System Presence of Hybrid-Fuzzy-VLLMS driven APF under
Un-Balanced Non-Linear Load
Fig.6.17 THD Analysis of Source Current withHybrid-Fuzzy-VLLMS Controller
Fig.6.16 illustrates the various simulation outcomes of three phase system presence of APF with proposed
Hybrid-Fuzzy VLLMS control strategy under un-balanced non-linear load device, in that (a) Source Voltage, (b)
Source Current, (c) Load Current, (d) Compensation Current, respectively. In this case load is treated as the un-
balanced non-linear load, due to this load device load currents are harmonized components, unbalanced. But source
currents maintain as harmonic-free and sinusoidal, balanced nature, well with in IEEE standards by using APF
compensator by using attractive fundamental frequency based compensation currents. The THD of source current
with Hybrid-Fuzzy VLLMS controller driven APF is 0.41% have low harmonics well compensated by APF and
within an IEEE-519 standards as depicted in Fig.6.17. A Comparative analysis of Source Current THD’s in Various
Control Objectives under Balanced and Un-Balanced Load Condition is depicted in Table.6.2. In that, the hybrid-
fuzzy controlled based APF is best suited over classical PI and Fuzzy logic controller because of attaining very low
THD over these controllers and well within IEEE standards.A Comparative analysis of Source Current THD’s in
Various Control Objectives under Balanced and Un-Balanced Load Condition is depicted in Table.6.2. In that, the
hybrid-fuzzy controlled based APF is best suited over classical PI and Fuzzy logic controller because of attaining
very low THD over these controllers and well within IEEE standards. The graphical view of source-current THD in
several control schemes under balanced and un-balanced load conditions as depicted in Fig.6.18.
24. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
44 | Page
Table.6.2 Comparison of Source Current THD’s in Various Control Objectives under Balanced and Un-Balanced
Load Condition
THD (%)
With
out
Cont
roller
PI-
VLL
MS
Contr
oller
Fuzz
y-
VLL
MS
Cont
roller
Hybrid-
Fuzzy-
VLLMS
Controll
er
Source
Current
(Under
Balanced
Non-Linear
Load)
30.29
%
1.91% 0.42
%
0.29%
Source
Current
(Under Un-
Balanced
Non-Linear
Load)
30.29
%
1.79% 0.61
%
0.41%
Fig. 6.18 Graphical View of Source Current THD under Various Controllers
25. Fuzzy Controller Based Power Quality Improvement Using VLLMS Based Shunt Active Power Filter
45 | Page
VII. Conclusion
In this work, a new control design for the shunt active power filter has been presented. The controller design is
based on Hybrid-Fuzzy-Logic controller based VLLMS algorithm for fundamental current extraction. With the use
of this proposed algorithm, the performance of shunt active filter has been enhanced in various load conditions like
balanced and unbalanced nonlinear load currents. Self-charging capability has also been integrated into the proposed
shunt active power filter for regulating the dc capacitor voltage. Simulation results under various system operating
conditions have verified the effectiveness and robustness of the proposed adaptive shunt active filter under balanced
and unbalanced load conditions. The THD of source currents under classical PI and intelligent hybrid fuzzy
controllers are evaluated, the hybrid-fuzzy is the best suited due to low THD profile, high stability index, and the
well within IEEE-519 standards.
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