In a significant academic accomplishment, Dr Ramanjaneya Reddy, Assistant Professor in the Department of Electrical and Electronics Engineering, along with UG students Ms Mehataj Syed and Mr Busam Gopichand, have recently published a groundbreaking paper titled “A Three Leg Asymmetrical Voltage Resonant Converter with Independent Dimming Control for Multiple Load LED Lighting Applications” in the esteemed Q1 journal IEEE Transactions on Industry Applications. The journal boasts an impressive impact factor of 4.4, further underscoring the importance of this research contribution.

The paper delves into the development of a novel Three Leg Asymmetrical Voltage Resonant Converter that offers independent dimming control for multiple load LED lighting applications. This innovation holds great promise for enhancing the efficiency and versatility of LED lighting systems, paving the way for more sustainable and adaptable lighting solutions in various industrial applications.

Dr Ramanjaneya Reddy’s leadership and the collaborative efforts of Ms Mehataj Syed and Mr Busam Gopichand have culminated in this significant publication, which not only adds to the body of knowledge in the field but also showcases the talent and dedication of the researchers at the department.

This achievement highlights the commitment to excellence and innovation within the Department of Electrical and Electronics Engineering, positioning it as a hub for cutting-edge research and academic prowess. The impact of this research is expected to reverberate across the industry, contributing to advancements in LED lighting technology and its applications.

The publication of this paper underscores the quality and rigour of the research solidifying their reputation as leaders in the field. This accomplishment is a testament to the department’s commitment to pushing boundaries and making meaningful contributions to the field of electrical engineering.

Congratulations to Dr Ramanjaneya Reddy, Ms Mehataj Syed, and Mr Busam Gopichand on this remarkable achievement, and we look forward to seeing the continued impact of their research in the field.

Abstract

This work proposes a three-leg asymmetrical voltage resonant converter for multiple load Light Emitting Diode (LED) lighting applications. The proposed converter is developed with a common leg-1 for both load-1 and load-2. The load-1 is powered from asymmetrical voltage between leg-1 and leg-2. Similarly, load-2 is powered from asymmetrical voltage between leg-1 and leg-3. The proposed circuit provides the following major contributions: (1) Independent dimming control of LED loads; (2) Zero Voltage Switching (ZVS) of all power switches; (3) High efficiency; and (4) Asymmetrical voltage regulation. To achieve independent dimming control, the voltages between legs are made zero by dimming leg-2 and leg-3 independently. Two resonant circuits are connected in the proposed circuit. Owing to this all the power switches operate with ZVS, which reduces the switching losses. Further, two LED lamps are connected in series with battery sources to supply the threshold voltage to lamps which in turn results in a lower power processing of the converter.

Explanation of Research in Layperson’s Terms

This work proposes a three-leg asymmetrical voltage resonant converter with independent dimming control for multiple load LED lighting applications. The proposed converter drives multiple loads independently with a dimming feature. The converter is developed with leg-1 is common for both LED loads. The major contributions of the proposed LED driver are independent dimming control, asymmetrical voltage regulation, zero voltage switching of all the power switches, and high efficiency. The threshold voltage of LED loads is supplied by batteries connected in series with LED loads, which will help in lower power processing of the proposed converter. Further, due to soft switching technology implemented in this converter, it reduces the losses in the system considerably increasing efficiency.

Title of Research Paper in the Citation Format

A Three Leg Asymmetrical Voltage Resonant Converter with Independent Dimming Control for Multiple Load LED Lighting Applications.

Citation: Ramanjaneya Reddy Udumula, et. al, “A Three Leg Asymmetrical Voltage Resonant Converter with Independent Dimming Control for Multiple Load LED Lighting Applications,” IEEE Transactions on Industry Applications, Feb 2024. doi: 10.1109/TIA.2024.3363676

Practical and Social Implementation of Research

To achieve effective and efficient use of energy resources under the sustainable development goals, Light Emitting Diodes (LEDs) have emerged as a global lighting industry solution. Over the conventional lighting sources such as incandescent lamps, fluorescent lamps, and high intensity discharge lamps, LEDs are i) more efficient, ii) eco-friendly due to absence of toxic gases, iii) have longer life span up to one lakh year, iv) high luminous intensity and v) good colour rendering index. LED’s requires low voltage direct current supply and the V-I characteristics of LEDs which is like Shockley diode represents the exponential growth of current over a small voltage variation which may damage the LED or effects the illumination. Hence, an LED driver is necessary in an LED system to supply LEDs with constant current. DC fed LED drivers are more reliable due to absence of AC-DC conversion stage and power factor correction stage which are crucial in AC fed LED drivers. Therefore, DC fed LED drivers are paid more attention in recent times in the majority of battery-powered/solar-powered applications. Given its features of high power, exceptional efficiency, cost-effectiveness, and flicker-free operation, this innovation is well-suited for streetlight/stadium lighting applications.

Collaborations

Dr. Kasi Ramakrishna Reddy, Assistant Professor
Department of Electrical and Electronics Engineering, Vasavi College of Engineering, Hyderabad

Future Research Plans

The future work is on PV/battery fed LED driver topologies suitable for streetlighting/stadium lighting applications with low component count, high efficiency, reduced device stress, and flicker free lighting system

Electric Vehicles are in vogue today, thanks to the heightened environmental concerns, greater availability of models, increased cost competitiveness and improved vehicle ranges. To contribute to the growing field of electric vehicle technology, Assistant Professors, Dr Tarkeshwar Mahto, Dr Somesh Vinayak Tewari and Dr Ramanjaneya Reddy from the Department of Electrical and Electronics Engineering at SRM University-AP along with the research scholar, Ms K Mounika Nagabushanam, conducted a study and published a research paper titled “Development of High-Gain Switched-Capacitor Based Bi-Directional Converter for Electric Vehicle Applications.” The team’s research focuses on creating a bi-directional DC-DC converter that enables power flow from the battery to the motor and vice versa while maintaining necessary voltage gains and ensuring improved efficiency and low cost.

Abstract

High efficiency, high voltage transfer ratio (VTR), and low input ripple current are required in any bidirectional DC-DC converter (BDC) that plays a major role in interfacing batteries in applications like DC microgrids and electric vehicles (EVs). To meet these requirements, a switched capacitor-based BDC is proposed to interface the battery with a propulsion system via a DC Link. It has a simple circuit with only a set of switching operations, High VTR, and lesser ripple current on the low voltage (LV) side, which are advantages of the proposed High Gain Switched-Capacitor Bi-directional DC-DC Converter (SC-BDC), making it appropriate for use in EVs. The steady-state analysis, design consideration of passive components, loss and efficiency analysis are presented. Finally, the proposed High Gain SC-BDC is compared with a few of the existing BDCs in the literature. The feasibility of the converter was demonstrated by simulating a 200 W converter and validating results produced in a MATLAB environment.

Practical implementation of your research or the social implications associated with it.

The developed converter can be used in Electric Vehicle for integration of battery to traction motor.

Collaborations.

1. Majed A. Alotaibi, Department of Electrical Engineering, College of Engineering, King Saud University, 11421, Saudi Arabia.

2. Hasmat Malik, Department of Electrical Power Engineering, Faculty of Electrical Engineering, University Technology Malaysia (UTM), Johor Bahru 81310, Malaysia.

3. Fausto Pedro García Márquez, Ingenium Research Group, Universidad Castilla-La Mancha, 13071 Ciudad Real, Spain.

As part of their future research plans the team plans of working on noise reduction methods that are brought on by regeneration action and to incorporate various control techniques to keep the DC link voltage of the propulsion system constant.

We wish the team all success in their future endevours!

Link to the article

 

Dr. Somesh Vinayak Tewari, Assistant Professor, Department of Electrical and Electronics Engineering (SRM University AP) was awarded the prestigious “Outstanding Doctoral Students Award”, from Homi Bhabha National Institute (HBNI) at an event held at the Department of Atomic Energy (DAE) Convention Centre, Anushaktinagar, Mumbai. Dr. Tewari was presented this award for his PhD thesis titled “Study of surface flashover of insulator in gases at high pressure.”

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Remarkable research of Dr. Tousif Khan N is honoured with APJ Abdul Kalam Memorial International Travel Award

SRM University AP, Andhra Pradesh faculty, Dr. Tousif Khan N, Assistant Professor and Head of the Department, Department of Electrical and Electronics Engineering, is to present a paper “Laguerre Neural Network Driven Adaptive Control of DC-DC Step Down Converter” in the renowned International Federation for Automatic Control (IFAC) World Congress to be held in Germany during July 12-17, 2020. Further this research article is also selected for the prestigious APJ Abdul Kalam Memorial International Travel Award by the Automatic Control and Dynamic Optimization Society (ACDOS) chaired by Professor Ravi Gudi of Indian Institute of Technology Bombay.

The research work of Dr. Tousif proposes a novel Laguerre neural network estimation technique for the approximation of unknown and uncertain load function, followed by its subsequent compensation in the adaptive backstepping controller. A detailed design of the proposed estimator and adaptive backstepping controller along with closed loop asymptotic stability have been presented. Further, the proposed control mechanism is evaluated through extensive numerical simulations while subjecting the converter to input voltage, reference voltage, and load resistance perturbations. Furthermore, the results are verified by testing the proposed controller on a laboratory prototype with DSP based TM320F240 controller board. The analysis of results reveals that the proposed control methodology for DC-DC step down converter offers a faster transient output voltage tracking with smooth and satisfactory inductor current response over a wide operating range. Dr. Tousif informs, “Under the class of DC-DC converters, the dynamics of DC-DC step down converter are nonlinear in nature and are largely influenced by both parametric and unanticipated external perturbations. In its closed loop operation, obtaining a precise output voltage tracking besides satisfactorily inductor current response is a challenging control objective. Hence, in this regard, this article proposes a solution.”

Electric power supply is the principal entity behind any electrical circuits and systems. Irrespective of their function in the digital domain, these circuits necessarily require a reliable and efficient energy source for their operations. Among the two existing forms of electrical energy, namely, the direct current (DC) and the alternating current (AC), the DC power finds wide use in numerous applications in the field of telecommunication, instrumentation, medical electronics, aerospace, defence and power transmission.

Ever since the fundamental innovations in DC systems by Thomas Alva Edison in 1880, DC rectification, and modulation method have remained central to various utilities. During the initial years, DC power conversion primarily resorted to the use of vacuum tube technology in delivering a desirable level of voltage from an AC source. The rectification stage was subsequently followed by filtering of the voltage at the output end. Nonetheless, the vacuum tube technology supported very low current density and featured a high ripple content in the DC voltage. Additionally, the output voltage was inconsistent or rather unregulated, making it inappropriate for DC power operated electrical and electronic systems. Much later in 1967, integrated series regulators were developed which eventually became popular as linear power supplies (LPS). Such a classical DC power generation method involved an AC transformer, AC-DC rectifier, and a voltage regulator in its assembly. The transistors in LPS operate under active region and dissipate large amounts of heat due to the voltage drop while high current flows through the collector-emitter junction, thereby causing substantial power loss and a very low energy efficiency. Even though they characterize the low level of noise and find better suitability in audio applications, yet their critical limitations of huge size, heavy weight and high cost make them infeasible for use in portable electronic devices.

In tandem to these aforementioned developments, the advancements in power semiconductor technology led to the invention of low cost reliable power switches exhibiting fast switching response. This proved to be instrumental in building an energy efficient switched mode power supply which gradually gained popularity. “Its impact on electrical technology was phenomenal, replacing conventional linear voltage supplies with switched mode power supplies giving rise to enhanced efficiency, light weight, compactness, and comparably lower cost. Such a modern DC conversion system primarily includes DC-DC converters, wherein the rectified input voltage is fed to the DC-DC converter circuits for obtaining specific voltage levels. The primary objective in DC-DC converters is to transfer the energy among different DC circuits functioning at a specific voltage and current levels. This process of energy transfer is performed by temporarily storing the energy from the input source in an operating mode, followed by releasing it in the other operational mode of the converter. Thus, one level of DC input voltage is converted to another level of average DC output voltage at the load end. Meanwhile, the converter being ideal is expected to consume no energy. Any consumption of energy in the converter interface amounts to direct power loss in the overall supply system. Typically, converters render high input-output conversion.”, enlightens Dr. Tousif Khan N. His notable research work offers to mitigate these issues, leading to the venerated APJ Abdul Kalam Memorial International Travel Award. Advancing his work in the future, Dr. Tousif will be closely working on the society’s activities with ACDOS as a member for mutual benefit.

Dr Somesh Tiwari has received Mentoring of Engineering Teachers by INAE (Indian National Academy of Engineering) Fellowship -2020.

Dr Somesh Vinayak Tewari, Assistant Professor, Department of Electronics and Electrical Engineering, brings another honour for SRM University-AP. He has been selected for Mentoring of Engineering Teachers by INAE (Indian National Academy of Engineering) Fellowship -2020. His mentor during the programme will be Dr Archana Sharma, FIE, FNAE, Outstanding Scientist, Bhabha Atomic Research Centre.

The INAE (Indian National Academy of Engineering) provides funding to an Engineering Teacher for carrying out research in the selected/proposed area to be mentored by an INAE fellow. The scheme attempts to increase the knowledge base and is instrumental in building long term collaborations. Such mentoring program helps in bridging the collaboration between an academic area and a research and development organization which is extremely necessary to sow the seeds of research in young and energetic brains so that they are able to translate their research ideas for further growth. This interaction of ideas leads to a win-win situation for both the University and the research organization. The prestigious and highly competitive fellowship receives thousands of applications nationwide though only fifteen of them finally are selected for the fellowship this year by INAE. Dr Somesh is one of fifteen outstanding researchers.

Dr Tiwari will be working on the proposed research topic- “Studies on Inertial Electrostatic Confinement Concept in Deuterium gas environment”. Inertial Electrostatic Confinement (IEC) is an alternative concept to Magnetic and Inertial fusion. IEC fusion device is an extremely compact and simple device, running by high voltage as discharge on Deuterium -Deuterium/Deuterium-Tritium/Deuterium -3He fuel gases. Studies related to IEC find application in the areas of dosimeter calibration, isotope production, radiography, and has medical applications. Such a research is multifaceted and helps an engineering teacher to enhance his skills in experimental areas of high voltage, plasma physics, vacuum techniques, radiation detection and measurement and in numerical methods and simulation leading to a comprehensive analysis of a given problem. During the two months of the fellowship, Dr Archana Sharma will be mentoring the project. It is an excellent opportunity for our faculty to work with such a renowned scientist in such close proximity. The collaboration will be beneficial for both institutions.

Dr Tousif Khan N, Head of the Department, Electrical and Electronics Engineering at SRM University-AP, Andhra Pradesh has been elected as a Joint Secretary (2020-2023) of the prestigious Automatic Control and Dynamic Optimization Society (ACDOS), Indian national member organization of International Federation of Automatic Control (IFAC). The objective of ACDOS is to promote automatic control and dynamic optimization fields in academia and industry across India. The society aims to host international conferences and technical workshops regularly in order to promote close interaction between industry professionals and academia. The society also participates in curriculum development for graduate and under-graduate studies in addition to facilitating productive research in this area. The society volunteers to honour eminent persons who excelled in this field in industry and academic circles.

Dr Tousif Khan N is an Assistant Professor in the Department of Electronics and Electrical Engineering at SRM University-AP, Andhra Pradesh. He has obtained his PhD from Indian Institute of Technology, Guwahati. Apart from performing his duties as a teacher, he is pursuing his research career in Control systems, Power Electronics and Optimization Techniques. The very young and talented professor has been honoured with several awards and recognitions for his pursuits in the domains of Teaching and Research. As a Joint Secretary of ACDOS, Dr Khan wishes to contribute further to the versatile worlds of Research and Academia.

The other members of ACDOS are eminent researchers and scientists such as Prof. Sukumar Mishra (IIT Delhi) as President, Dr Jayesh Barve (GE, Bangalore) as Vice-President and President-Elect, Dr Shaik Faruque Ali (IIT Madras) Vice-President, Prof Bidyadhar Subudhi (IIT Goa) as Vice-President, Dr Arnab Maity (IIT Bombay) as General Secretary, Dr S. N Omkar (IISc-Bangalore) as Treasurer and Prof Radhakant Padhi (IISc Bangalore) as Director of Operations.

To know more about ACDOS, please click the link: https://www.acdos.org/

Ms Sravani Sanikommu, a vibrant and keen third-year Electrical and Electronics Engineering (EEE) student from SRM University-AP, has been selected for the prestigious Mentoring of Engineering Students by INAE Fellows Programme by the Governing Council of Indian National Academy of Engineering (INAE). She is one amongst 59 brilliant students who have been selected from across the country this year. The objective of this distinguished programme is to mentor outstanding B.E/BTech undergraduates by INAE fellows. Meritorious 3rd /4th year B.E./B. Tech students from recognised Engineering institutions are eligible under the scheme. Candidates must have a minimum of 75% or a CGPA of 7.5 to be considered for this programme. The mentorship program takes place through an online medium.

The Governing Council of the Indian National Academy of Engineers (INAE) designed the mentoring programme to encourage future engineers in the nation to make significant contributions to engineering and technology for holistic solutions. Due to COVID-19 pandemic, online internship is also available. Ms Sravani gets an opportunity to work online in the host institution in the field of power electronics under the able mentorship of INAE Fellow Prof B G Fernandes, Electrical Engineering, Indian Institute of Technology Bombay (https://www.ee.iitb.ac.in/wiki/faculty/bgf) for 2 Months. She extended her gratitude to Dr Tousif Khan N, the Head of the Department, and Prof Sastry V Vedula, a distinguished visiting professor in the Department of Electrical and Electronics Engineering, as well as an INAE fellow, for initiating her into the mentoring programme and providing constant guidance.

Sravani stated that she had complete supervision of faculty members of SRM-AP during the preparation for this two month Mentoring Programme. The extensive research expertise of faculty members aided significantly throughout the selection process among the finest applicants. “I thank everybody who has put efforts into making this happen. SRMAP can provide such amazing opportunities to research in the fields in which students are interested in working. This is made possible through the faculty members who are experienced in the specified fields which helps the students to learn more about the subject and form a substantial idea on how the concepts work. If somebody is keenly interested in research on something they love and are very passionate about it, SRMAP is the right place!!”, said Ms Sravani with overwhelming enthusiasm.

“Compact Inertial Electrostatic Confinement D-D Fusion Neutron Generator” is an imbuing research paper co-authored and published by Dr Somesh Vinayak Tewari, Assistant Professor in the Department of Electrical and Electronics Engineering (EEE), SRM University – AP, in the scientific journal, Annals of Nuclear Energy.

This paper is part of an interdisciplinary work leveraging the areas of both electrical engineering and physics. Inertial Electrostatic Confinement (IEC) Systems are simple, compact and operate on high voltage discharge in Deuterium- Deuterium (D-D)/ Deuterium-Tritium (D-T) gases between concentric grids for neutron generation. Such systems find considerable applications in the detection of explosives and illicit materials, radiography, tomography, and neutron well logging. The IEC system cathode temperature is measured with a Fibre Bragg Grating (FBG) during the measurement of neutrons from the system. FBG is optical fibre sensors that can be used for sensing temperature by recording the Bragg wavelength shift. The advantage of such measurements is that they can be used in environments such as electric arcs and plasmas, chemical and nuclear zones unaffected by electromagnetic fields such that the signals can be monitored remotely.

The production of neutron fluxes for the above-mentioned applications is through radioisotopes, accelerators, or nuclear reactors with the inherent nature of their complexity, hazards, and problem of residual radioactivity. Additionally, such systems require a considerable amount of shielding and Dr Tewari puts forth such factors that prompt further research in the area of the development of much simpler compact IEC systems.

The said research project has been carried out under the scheme of “Mentoring of Engineering Teacher by an INAE Fellow”, financially supported by the Indian National Academy of Engineering. The work goes forward in close collaboration with Pulsed Power & Electromagnetic Division, Beam Technology Development Group, Bhabha Atomic Research Centre (BARC)-Vishakhapatnam.

The future projects of Dr Tewari involve working on simulations related to the compact IEC for study, analysis, optimization of different parameters of an IEC system and related experimentation in collaboration with BARC.

Dr Tarkeshwar Mahato ResearchDr Tarkeshwar Mahto, Assistant Professor, in the Department of Electrical and Electronics Engineering has published a paper titled “Design and Implementation of Frequency Controller for Wind Energy-Based Hybrid Power System Using Quasi-Oppositional Harmonic Search Algorithm” in the reputed research journal, Energies.

An innovative union of fuzzy controller and proportional-integral-derivative (PID) controller under the environment of fractional order (FO) calculus is described in the present study for an isolated hybrid power system (IHPS) in the context of load frequency control. The proposed controller is designated as FO-fuzzy PID (FO-F-PID) controller. The undertaken model of IHPS presented here involves different independent power-producing units, a wind energy-based generator, a diesel engine-based generator and a device for energy storage (such as a superconducting magnetic energy storage system). The selection of the system and controller gains was achieved through a unique quasi-oppositional harmony search (QOHS) algorithm. The QOHS algorithm is based on the basic harmony search (HS) algorithm, in which the combined concept of quasi-opposition initialization and HS algorithm fastens the profile of convergence for the algorithm. The competency and potency of the intended FO-F-PID controller were verified by comparing its performance with three different controllers (integer-order (IO)-fuzzy-PID (IO-F-PID) controller, FO-PID and IO-PID controller) in terms of deviation in frequency and power under distinct perturbations in load demand conditions. The obtained simulation results validate the cutting-edge functioning of the projected FO-F-PID controller over the IO-F-PID, FO-PID and IO-PID controllers under non-linear and linear functioning conditions. In addition, the intended FO-F-PID controller, considered a hybrid model, proved to be more robust against the mismatches in loading and the non-linearity in the form of rate constraint under the deviation in frequency and power front.

The research group believes that the study will boost the use of renewable energy utilization for fulfilling energy requirements in a more reliable and stable manner. In future, they plan to use the knowledge gained from the isolated systems to develop a Multi-Migrigrid system.

Collaborations:

  1. Department of Electrical and Electronics Engineering, M S Ramaiah Institute of Technology, Bengaluru 560054, India
  2. The Berkeley Education Alliance for Research in Singapore, The National University of Singapore, Singapore 138602, Singapore
  3. Clean and Resilient Energy Systems (CARES) Lab, Texas A&M University, Galveston, TX 77553, USA;
  4. Department of Electrical Engineering, College of Engineering, Taif University, Taif 21944, Saudi Arabia

Dr Somesh Vinayak Tewari delivered an invited talk on “High Power Closing Switches” on November 25, 2021, during the Workshop on Pulse Power Technology and Applications (WSPPTA-2021) held from November 25, 2021, to November 27, 2021, at Bhabha Atomic Research Centre (BARC) Facility, Visakhapatnam, sponsored by Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy, Government of India in association with Power Beam Society of India.

The workshop served as a platform for pedagogical presentations, discussions on intricacies of pulsed power technology and mutual interactions among young researchers, engineers and students from academia and applied research laboratories and talks were delivered by scientists of BARC, IPR, DRDO, CEERI, professors from IIT, IISc and experts from industry.

Dr Tewari delivered a talk on “High Power Closing Switches”, highlighting the working principle, mechanism, and applications of vacuum switches like ignitron, thyratron, pseudo spark gap, gas-filled spark gap switches, liquid and solid dielectric switches, magnetic switches, and modern-day semiconductor switches.

After his talk, Dr Tewari was highly appreciated and felicitated by Dr D. C. Pande, Dr Raja Ramana Distinguished Fellow of DRDO. The proceedings were compiled in the form of book chapters and circulated to participants.