Modelling, design and control of power electronic converters for smart grids and electric vehicle applications

The electrical energy sector is currently experiencing an interesting and paradigm shift due to recent rapid technological developments. Such developments are predominantly related to renewable energy, smart grids, energy storage and electric vehicles. There is a strong technical connection between all the above-mentioned fields. For instance, the penetration of renewable energy coupled with energy storage facilities and suitably controlled through appropriate communication protocols paves the way for realizing a smart grid. The swift progress and adoption of electric vehicle by various entities proves to be a boon for all the stake holders involved. Soon, with the proliferation of electric vehicles, interesting and challenging interactions between the electric vehicle and the smart grid are expected. Power electronic converters play a pivotal role in the smooth and coordinated functioning of all the four above-mentioned applications. The current Special Issue focuses on “Modelling, Design and Control of Power Electronic Converters for Smart Grids and Electric Vehicle Applications.”

In this Special Issue, we received thirty-one papers, all of which were peer reviewed. Of the thirty-one originally submitted papers, twelve papers have been accepted, six were “rejected with referral” since they did not meet the criteria to be considered for the IET Power Electronics Special Issue. However, considering their quality, they were referred for possible publication in another journal. Thus, the success of this Special Issue is well-appreciated through the quality of submissions.

The twelve accepted papers are grouped under three main categories viz., DC microgrid and smart grid applications, electric vehicle (EV) and motors drive applications, and power system applications. The papers clustered under the first category present high gain DC-DC converters with attractive features which are preferred for DC microgrid and smart grid applications. Four papers have been grouped under this category. There are four papers which discuss the role of power converters for EV and motor drive applications which is the second group. Two papers discuss the converters employed for EV battery charging along with suitable control techniques. The third category is based on the power converters employed for power system applications. There are four accepted papers which deal with the application.

Mahnaz Izadi et al. present an improved coupled inductor-based high gain DC-DC converter. The switch employed in the converter is subjected to minimal overshoot due to the clamp circuit which recycles the energy stored in the leakage inductance. The proposed converter operates with a full-load efficiency of 95.5% and yields a voltage conversion ratio of 10. Due to its beneficial features, the proposed converter is suitable to integrate low-voltage DC sources to the consumers and/or DC networks.

Mostafa Karimi Hajiabadi et al. discuss a high step-up DC-DC converter which is suitable for integrating renewable energy sources with a common DC bus. The proposed converter operates with a wide duty ratio ranging from 0.4 to 0.6 and yields a good voltage gain value of 10.9. The converter possesses beneficial features viz., common ground and better total device count to voltage gain ratio besides utilizing semiconductor devices with low voltage ratings.

Nilanjan Tewari et al. explore a reconfigurable high gain DC-DC converter. The proposed converter utilizes hybrid combination of gain extension mechanisms viz., switched capacitor and switched inductor-capacitor-inductor cells to achieve a voltage conversion ratio of 15.2. A couple of added advantages of the proposed converter are its modularity and ability to provide high voltage conversion ratios at low duty ratio values. Therefore, the converter is expected to be a suitable option for integrating the low voltage renewable energy input to a high voltage common DC bus.

Ramachandran Rajesh et al. present the stability and reliability analysis of a high gain DC-DC converter. A reliability analysis is performed to predict the failure rate and lifetime of the individual components using the military handbook (MIL-HDBK-217F). Based on the analysis, the semiconductor devices are more prone to failure than the other components. The stability analysis is also verified through the properly tune proportional-integral-derivative (PID) controller.

Serhat Emir Ogan et al. discuss the effects of modulation and motor characteristics that impact the capacitor sizing of three-level neutral point clamped voltage source inverter implemented for electric vehicles. The paper investigates the impact of combining interdependent characteristics such as power factor, modulation index, current, and fundamental frequency on the capacitor sizing. The effect of various modulation methods is also presented in detail.

Lynn Verkroost et al. explore the multi-agent-based voltage balancing in modular motor drives with series-connected power electronic converters. The research proposes a multi-agent voltage balancing algorithm based on dynamic average consensus, which depends solely on local computations, local measurements, and neighbour-to-neighbour communication. Both simulations and experiments proved the feasibility of the proposed strategy.

Jingang Han et al. present a predictive load-feedforward control strategy to suppress DC link voltage fluctuations and improve the dynamic performance of the converter. The system structure for battery charging and discharging is developed initially followed by the development of a predictive load-feedforward model. The developed hypothesis is verified through simulation and experimentation.

Mohammed-Amine Mossadak et al. discuss a backstepping cascaded controller for battery-supercapacitor electric vehicles. The paper considers various driving cycle scenarios while designing the controller to regulate the DC-bus voltage under uncertainties and load variations. The functionality of the proposed controller is validated through MATLAB/Simulink based simulation.

Alireza Lahooti Eshkevari et al. introduce a new direct step-up AC-AC converter designed based on the SEPIC. The converter provides higher step-up conversion ratio than some of its other counterparts. Further, it possesses some valuable features viz., high efficiency, reasonable input and output total harmonic distortions (THD), continuous input current waveform, common ground, few components, and single-stage conversion without snubber and LC filters. Hence, the proposed converter is suitable for inductive power transfer from low-voltage AC sources, to any applications that require a boost AC-AC converter with optimal component count.

Iman Abdoli et al. propose an isolated single-phase impedance-source AC-AC converter with a wide voltage conversion ratio and a safe commutation strategy. The proposed converter achieves galvanic isolation by employing a high-frequency transformer (HFT), eliminating low-frequency transformers (LFT) from the topology. The proposed converter is suitable for dynamic voltage restorer (DVR) applications.

Farzaneh Bagheri et al. present a second-order sliding mode control strategy for DVR. The proposed control method alleviates chattering and achieves finite-time convergence. The effectiveness of the proposed method is verified through simulation and experimental results.

Zhilong Zhang et al. explore the harmonic oscillation and compare the stabilization methods in a shunt active power filter (SAPF). Generally, the SAPF employs complex harmonic detection algorithm, which significantly increases the computational demands. The proposed full-compensation mode solves this problem. Initially, the small signal model of the SAPF system in full compensation mode is established. Next, the oscillation mechanism of the SAPF system is investigated. Based on the model, the working mechanism and application performance of the main stabilization methods proposed in the past are analyzed and compared. Finally, simulations and experiments are performed to verify the mechanism analysis and proposed methods.

All the papers accepted for this Special Issue clearly signify that the role of power converters in smart grid and electric vehicle applications is undergoing a rapid growth. Many novel topologies, and control techniques are expected to evolve in the coming years.

Mahalingam Prabhakar received his B.E. degree in electrical and electronics engineering in 1998 from the University of Madras, Chennai, India. He received the M.E. degree in power electronics and drives from Bharathidasan University, Tiruchirappalli, India in 2000 and the Ph.D. degree in electrical engineering from Anna University, Chennai, India in 2012. He started his teaching career as lecturer in 2000. Since 2012, he has been an associate professor with the School of Electrical Engineering (SELECT), Vellore Institute of Technology, Chennai India. He is working as a professor since 2019 and is associated with the Centre of Smart Grid Technologies from May 2022 onwards. He has co-authored more than 50 research articles in various reputed journals and conferences. His research interests include power converters, high gain DC-DC converters, multi-input converters, and DC microgrids. He is an active reviewer of various reputed journals. He was a recipient of the Outstanding Teacher Award for his excellent teaching and research contributions in 2009. He is a recipient of Research Award which is awarded by Vellore Institute of Technology, Chennai for his research contributions continuously from 2012 till date.

Fernando Lessa Tofoli received the B.Sc., M.Sc., and Ph.D. degrees in electrical engineering from the Federal University of Uberlândia, Uberlândia, Brazil, in 1999, 2002, and 2005, respectively. Currently, he is a professor with the Federal University of São João del-Rei, São João del-Rei, Brazil. His research interests include power-quality-related issues, high-power-factor rectifiers, non-isolated dc-dc converters with a wide voltage conversion range, novel converter topologies, and solar photovoltaic systems.

Mohammed A. Elgendy received his B.Sc. degree from Menoufia University, Menoufia, Egypt, in 1997, the M.Sc. degree from Ain Shams University, Cairo, Egypt, in 2003, and the Ph.D. degree from Newcastle University, Newcastle upon Tyne, UK, in 2010, all in electrical engineering. From 1998 to 2006, he was a research assistant with the New and Renewable Energy Department, Desert Research Centre, Cairo. From 2011 to 2014, he was a research associate with the Electrical Power Research Group, Newcastle University, where he currently holds the position of a lecturer. His current research focus is on the design and control of power electronic converters for renewable energy systems, battery energy storage systems, and electric drives.

Huai Wang is currently a professor at the Department of Energy, Aalborg University, Denmark, where he leads the Reliability of Power Electronic Converters (ReliaPEC) group. He is also the head of Mission on Digital Transformation and AI, with 13 affiliated research groups, to enable the next leap in transforming energy systems by bridging the multi-disciplinary research and innovation in energy, digitalization, and AI. His research addresses the fundamental challenges and application issues in efficient, reliable, and cognitive power electronic converters functioning as energy processors for our electrified and digitalized world. He collaborates widely with industry companies across the value chain, from power electronic materials and components to systems. He has contributed a few original concepts and methods to power electronics reliability and passive components and received six paper awards from IEEE and IET. In addition, he has given more than 100 invited talks in universities, companies, and conferences. Dr. Wang received his Ph.D. degree from the City University of Hong Kong in 2012 and a B. E. degree from the Huazhong University of Science and Technology in 2007. He was a short-term visiting scientist with the Massachusetts Institute of Technology (MIT) in 2013 and ETH Zurich in 2014. He was with the ABB Corporate Research Center, Switzerland, in 2009. He received the Richard M. Bass Outstanding Young Power Electronics Engineer Award from the IEEE Power Electronics Society in 2016 for his contribution to the reliability of power electronic converter systems. He serves as the chair of IEEE IAS/IES/PELS Chapter in Denmark and the editorial board of four journals from IEEE, Springer Nature, and Elsevier.