In a significant stride towards sustainable energy solutions, a team of researchers from the Department of Electrical and Electronic Engineering has unveiled a groundbreaking innovation. Their paper titled “A Novel Multi-Port High-Gain Bidirectional DC–DC Converter for Energy Storage System Integration with DC Microgrids” has been accepted in the prestigious Q1 Journal of Energy Storage, boasting an impressive impact factor of 9.4. The study focuses on addressing the critical challenges associated with energy storage systems (ESS) in direct current (DC) microgrids. Dr Ramanjaneya Reddy, Assistant Professor, Dr Tarkeshwar Mahto, Assistant Professor, and Mrs Maya Vijayan, a dedicated PhD Scholar, collaborated to design a multi-port high-gain bidirectional DC-DC converter. This innovative converter facilitates seamless integration of energy storage systems with DC microgrids, enhancing overall system efficiency and reliability.

Abstract

Bidirectional converters have often been used in numerous applications like DC microgrids, renewable energy, hybrid energy storage systems, electric vehicles, etc. The paper proposes a novel multi-port high-gain (NMPHG) bidirectional DC-DC converter that supports DC microgrid (DC-MG) applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, multiple input ports, lower switch voltage stress, and lower component count owing to the single converter with multiple input ports for DC microgrid applications.

The detailed operational principle, analysis, and design considerations of proposed NMPHG bidirectional DC-DC converters are discussed. Furthermore, the loss analysis, detailed comparison with similar works, and efficiency analysis with non-modalities during forward power flow (LV to HV) and reverse power flow (HV to LV) modes are presented. The efficiency of the proposed converter is found to be 93.8% in forward power flow and 92.9% in reverse power flow modes at rated power. Finally, a hardware prototype of the proposed NMPHG bidirectional DC-DC converter is implemented with 100 W in FPF mode and 200 W in RPF mode with a TMS320F28335 processor and validated with theoretical counterparts.

Explanation of Research in Layperson’s Terms

The proposed converter is a 200W bidirectional topology used in DC microgrid applications such as renewable energy, hybrid energy storage systems, and electric vehicles. The converter can accept two or more sources to supply the load. Thus, it is suitable for various applications of traction vehicles. It exhibits a lower switch stress and reduces the component ratings to lower values.

Title of Research Paper in the Citation Format

A NOVEL MULTI-PORT HIGH-GAIN BIDIRECTIONAL DC-DC CONVERTER FOR ENERGY STORAGE SYSTEM INTEGRATION WITH DC MICROGRIDS

Vijayan, Maya, Ramanjaneya Reddy Udumula, Tarkeshwar Mahto, and Ravi Eswar KM. “A novel multi-port high-gain bidirectional DC-DC converter for energy storage system integration with DC microgrids.” Journal of Energy Storage 87 (2024): 111431.

Practical Implementation or the Social Implications Associated with it

The features include port expandability on the source side, lower switch voltage stress, bidirectional property, and fewer components. It is most suitable for electric vehicles, Unmanned ariel vehicles, and energy storage systems at renewable power plants, etc. It improves the reliability of the grid system whereas hybrid energy storage systems with battery or supercapacitor will improve system stability.

It can be used in various on-grid and off-grid applications like hospitals, offices, and educational institutions, especially where energy backup is very important. These types of converters are more specific for use in fast power transition required such as EVs, drones, aircraft, space vehicles, etc. The major advantage is the reduction in the size of the converter due to multiple source capability and ease of control.

Future Research Plans

We plan to work on a bidirectional converter with better efficiency and ultra-high gain. That should be able to reduce the size of the converter and the source ratings too. Design and implement bidirectional multi-port converters for various applications of DC microgrids, such as renewable and hybrid storage integration.

Link to the Article

It is with great pleasure that we announce the publication of a research paper titled “Self-Learning Controller Design for DC-DC Power Converters with Enhanced Dynamic Performance,” jointly authored by Dr Tousif Khan N, Associate Professor, Department of Electrical and Electronics Engineering, and Dr Ramanjaneya Reddy & Dr Arghya Chakravarty, Assistant Professors, Department of Electrical and Electronics Engineering. The research paper introduces a novel self-learning control for precise output voltage tracking in DC-DC buck power converters.

Abstract:

This article introduces a self-learning robust control approach for accurate output voltage tracking in DC-DC buck power converters, focusing on scenarios with high precision requirements and significant load uncertainties. The method employs a simple online neural network to swiftly estimate unexpected load changes and disturbances across a wide range. Operating within a backstepping framework, the controller utilises neural network-learned uncertainties to enhance stability and improve dynamic and steady-state performance of both output voltage and inductor current. Extensive numerical simulations and practical experiments on a laboratory prototype demonstrate substantial enhancements in dynamic performance with a 94% reduction in settling time and precise steady-state tracking. The reliability of the proposed controller is further supported by the consistency between computational and experimental outcomes, showcasing its potential for real-world applications.

Practical implementations:

The proposed controller can be implemented/used for robotics applications, industrial processes, and medical equipment where precise control is needed.

Future research plans:

The following are the potential future directions of the proposed work;

(i) Design and development of the proposed self-learning neural network-based control for DC-DC buck converter systems with real-time DC sources, such as solar PV and fuel cells, experiencing highly intermittent input voltage changes.

(ii) Incorporating inductor current constraints and output voltage limitations into the proposed controller would also be an avenue worth exploring.

We congratulate the professors for their valuable contribution and look forward to future breakthroughs in this area.

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

The Department of Electrical and Electronics Engineering is glad to announce that Dr Tousif Khan, Associate Professor and HOD, has been selected as the General Secretary of the Prestigious Automatic Control and Dynamic Optimization Society (ACDOS), National Member Organisation of the International Federation of Automatic Control (IFAC), at the Governing Council meeting held on June 22, 2023.

Automatic Control & Dynamic Optimization Society (ACDOS) was established in 2011 with the noble objective to promote automatic control and dynamic optimization discipline 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 and academia. The society also participates in curriculum development for graduate and undergraduate studies and facilitates productive research in this field. The society also volunteers to honour eminent persons who excelled in this field in industry and academic circles.

Congratulations to Dr Tousif for this remarkable accomplishment and for further contributing to the university’s rising reputation among national and international frontiers!