Serving the Power Electronics Community Proudly [From the Editor

Some fundamental considerations regarding power electronics and machine electronics are discussed. The historical development of ideas in this field is examined, the applications in the field of electric traction for rail vehicles are summarised and possible future developments are outlined. A systematic approach to power electronics, based upon the control of energy flow in switching convertors, is presented. This approach takes into consideration the different possible switching functions, the modulation functions, the realisation of these switching and modulation functions, the realisation of these switching and modulation functions by practical power semiconductor switches and the different classes of forced turn-off and commutation in power electronic circuits. Subsequently the concepts of topology and structure are defined, leading to different generic topologies for singular convertors. The structure of the five different families of composite convertors are examined, and practical examples are given.The systematic approach to machine electronics presented in the paper is based on a power flow model, using the unifying concept of rotating field theory. In combination with previously defined systematics for power electronics, this enables a systematic approach to the different classes of variable speed drives, based on power flow considerations.The historical developments of some power electronic and machine electronic ideas are traced, starting at the beginning of this century. Since the introduction of power semiconductor switches, applications of the older ideas have increased exponentially in all fields, making it impossible to cover all of them. As a consequence the development of power electronics and control of machines by electronic convertors in the field of electric traction is discussed in some detail, because this represents a record of important engineering achievements in this field.In conclusion, the present state and future trends of power and machine electronics are examined. This evaluation covers the development in the field of switching devices regarding the improvement of interfacing between signal and power electronics, the decrease of switching transition times, the reduction of device losses during conduction, and device developments for decreasing energy storage devices in convertors.The development of power electronic convertors for the reduction of the number of components in the topology and the development of convertors with a high frequency link are then covered, related to the expected development of switching devices.New directions of development regarding the electronic conditioning of the electromechanical energy conversion process concerning the elimination of undesirable effects and losses are important. The implementation of these trends by utilising the improved switching characteristics of power electronic switches and the information processing capability of microprocessors is discussed. This is then extended toward control aspects, where both these characteristics enable solutions not possible hitherto. Field control of AC machines imparts control characteristics equal to, or better than, those obtainable with DC machines to the systems, while the processing capability of microprocessors allows the configuration of adaptive machine electronic systems. Finally attention is given to the interfacing of power electronic and machine electronic systems to the power supply network. If the exponential growth of the installed capacity of equipment in the future is to be handled, active compensation of the distorted currents drawn from the supply by this equipment will have to be considered seriously.

This paper describes the experience gained with the development and use of modular teaching equipment for the Power Electronics Laboratory in the Federal Center of Technology Education of the state of Minas Gerais, Brazil. Conception, construction as well as pedagogic issues are addressed. The equipment was developed to be cost-effective, safe, easy to use, flexible and robust. Experiments contents are also presented. It will be shown that the developed equipment allowed straightforward realization of several hands-on experiments on DC motor drive, monophase inverters, some non-isolated PWM choppers and DC-DC converters topologies, line commutated monophase and threephase controlled and uncontrolled rectifiers. The equipment can also be used in higher levels power electronics courses, since it is modular. I. INTRODUCTION Laboratory experiments in undergraduate courses are often used to assist and complement the classroom lectures. They are an important tool for improving student's hands-on skills like measuring, corroborating practical results, comparing theory and practice, modeling, etc. But the complexity of the power electronics systems makes the laboratory experiments implementation not so simple. The Power Electronics field is very multidisciplinary, and several authors have mentioned this fact (1,2,3,6). There are also class time restrictions in virtually all courses, and one of the lecturer's challenges is to adjust the deepness and the broadness of the used approach (3). When implementing practical power electronic converters, EMI and parasitic elements issues can ruin the results if not observed and correctly managed. In this context, a well planned teaching equipment can help a lot. It can save class time and spur student's motivation. The power electronics group at the Centro Federal de Educacao Tecnologica de Minas Gerais (Federal Center of Technology Education of the state of Minas Gerais) - CEFET-MG, has been developing equipment for the electronics technician course and for the electrical engineering course since the year 2000. The key idea is to provide the power electronics laboratory with cost-effective, robust, flexible, safe and easy to use teaching equipment, which could make the laboratory classes more profitable than they were in their earlier versions. It should be pointed out that the equipment have been planned and assembled entirely in the school, using simple resources. The power electronics curricula of the electronics technician course and the electrical engineering courses at CEFET-MG are covered in two semesters. Both curricula share most common subjects and the laboratory as well. The basic difference is the approach's deepness and the use of calculus in the undergraduate level. The focus is on the basic principles of the power electronics converters. Simulation resources are used as an aid, and excellent results have been achieved with the demo version of the Psim package from Powersim (7). The discussion about this topic will be presented in a further work. In a previous paper (1), we discussed some laboratory experiments approaches and presented assembly details of the developed modules. Also, some modules like the phase- controlled rectifiers have been presented. In this paper it will be presented the new developed modules (section II), as well as some experiments and its results (section III). II. SOME DEVELOPED MODULES Regarding modularity, the adopted concept was to divide the power electronics systems in up to three modules: the power converter module, which comprises the switching devices and the energy storage elements, the command / control module and finally the gate driver modules. It was found that this arrangement provides a better understanding by the students and the utilization of the modules in a broader diversity of experiments. Figure 1 shows the block diagram of the fragmented system.

Energy and research on energy systems places a focus on all facets of electrical energy, as well as innovation in energy production and delivery, alternative resources, and efficient devices. Systems and equipment for converting, providing, and utilising energy as a kind of electricity are the subject of research initiatives. Power electronics are now a more integral part of power systems, enhancing quality and efficiency and fostering the gradual materialization of intelligent, efficient energy. Many different types of power electronics exist in power systems. The architectural study of changing electrical transformed from one medium to another is known as power electronics. Fields such as electronics reprocess or recover more than 80percent of the entire of the electricity produced at a world average rate of 3.4 billion kilowatts per hour each year. Power electronics converters, sometimes referred to as power converters or switching converters, are used to process or convert electrical energy. Electricity comes in two flavours: AC power and DC power. The distribution system is divided into AC distribution systems and DC distribution systems based on the type of power it uses. Power system analysis is an essential part of electrical power system design. Calculations and simulations are performed to verify that the electrical system, including the system components, is properly specified to perform as planned, withstand the expected stress, and be protected from failures. Advantages of Power Electronics: High power density electricity. Improved efficiency up to 99% in energy conversion. Because to its efficiency and dependability, switching power supply are also being used in medical devices with acoustically sensitive applications. Power system reliability, in general, relates to problems like service interruption and power outages. This is frequently described as a goal to try relying on codes specifically relevant to the consumer. SAIFI, SAIDI, and CAIDI are common dependability index values for US applications. DEMATEL (Decision Making Trial and Evaluation Laboratory) They are divided into analysis using the Nonmetal mineral product industry, General equipment manufacturing, Mining and washing of coal, Textile industry, Food manufacturing industry It is the interaction between the factors Visualized and assesses dependent relationships Through the structural model Also deals with identifying important. Power Electronics in Power Systems, Power Electronics in Transportation Systems, Energy Conservation, Heating & Lighting Control and Renewable Energy Integration Power Systems and Power Electronics in Power Electronics in Power Systems is got the first rank whereas is the Energy Conservation is having the Lowest rank. Power Systems and Power Electronics in Power Electronics in Power Systems is got the first rank whereas is the Energy Conservation is having the Lowest rank.

In the past, automotive refrigerants have conventionally been used solely for the purpose of air conditioning. However, with the development of hybrid-electric vehicles and the incorporation of power electronics (PEs) into the automobile, automotive refrigerants are taking on a new role. Unfortunately, PEs have lifetimes and functionalities that are highly dependent on temperature and as a result thermal control plays an important role in the performance of PEs. Typically, PEs are placed in the engine compartment where the internal combustion engine (ICE) already produces substantial heat. Along with the ICE heat, the additional thermal energy produced by PEs themselves forces designers to use different cooling methods to prevent overheating. Generally, heat sinks and separate cooling loops are used to maintain the temperature. Disturbingly, the thermal control system can consume one third of the total volume and may weigh more than the PEs [1]. Hence, other avenues have been sought to cool PEs, including submerging PEs in automobile refrigerants to take advantage of two-phase cooling. The objective of this report is to explore the different automotive refrigerants presently available that could be used for PE cooling. Evaluation of the refrigerants will be done by comparing environmental effects and some thermo-physical propertiesmore » important to two-phase cooling, specifically measuring the dielectric strengths of potential candidates. Results of this report will be used to assess the different candidates with good potential for future use in PE cooling.« less

Today, with rapid development of science and technology in the 21<sup>st</sup> century, China has also obtained great achievements drawing world’s attention regarding application and research in power electronics technology and variable frequency technology field. This paper has intensively studied and discussed development and application of power electronic device and variable frequency technology. This paper has first analyzed current application situation and trends of power electronic device in new energy and power system, rail transit and electric car, energy saving of industrial motor, consumption electronics, and national defense and war industry, then discussed development history of variable frequency technology, hazards brought by power electronic device and countermeasures, and finally demonstrated future development of power electronics technology and expected a broad development prospect of variable-frequency regulating speed technology in the future.

The existing power grid infrastructures in many countries are primarily based on technologies that have been developed as centralized systems in which power is generated at major power plants and distributed to consumers through transmission and distribution lines. In the recent decade, with the increasing penetration of renewable energy sources such as solar and wind power, and smart electrical appliances, the centralized model may no longer hold, and the supply and demand for electricity become more dynamic. Moreover, the latest developed information and communication technologies (ICT) and power electronic technologies could enhance the efficiency and performance of power system operations. Recently, concerns with global warming have prompted many countries to announce research programs on smart grid, which is the transformation of the traditional electric power grid into an energy-efficient and environmentally friendly grid by the integration of ICT, power electronic, storage and control technologies. With the smart grid, there is an opportunity for a new operating paradigm that recognizes the changing structures of the power grid with renewable generation, and the high-resolution data, high speed communications, and high performance computation available with the advanced information infrastructure. A new operating paradigm, namely, risk-limiting dispatch, is proposed for the smart grid in this paper. In addition, we have identified the requirements of a communication infrastructure to support this new operating paradigm.

With the speedy progress in electrical engineering field globally, power electronics course has aroused attention from academic community. English immersion teaching methods applied to power electronics course aim to introduce advanced counterpart academic knowledge from abroad to China and equip students and teaching staffs with international views as well as English-oriented logical and critical thinking in power electronics, and thus to promote power electronics development in China in the long term. By utilizing English immersion teaching methods for power electronics course, which involves problem-based learning, English-project-based assessment method and English-based laboratory operation, the challenges that the innovative teaching methods confront could be solved during each process of power electronics course. For further illustration, English immersion teaching methods for energy storage will be analysed as a study case. Consequently, the new English immersion teaching methods for power electronics course in China can be spread and applied in other non-native English-speaking countries to upgrade and reform power electronics course and related discipline.

Chapter 4 - Power electronics for smart grids

A review of power electronics interfaces for distributed energy systems towards achieving low-cost modular design

The use of renewable energy sources is increasingly being pursued as a supplemental and an alternative to traditional energy generation. Several distributed energy systems are expected to a have a significant impact on the energy industry in the near future. As such, the renewable energy systems are presently undergoing a rapid change in technology and use. Such a feature is enabled clearly by power electronics. Both the solar-thermal and photovoltaic (PV) technologies have an almost exponential growth in installed capacity and applications. Both of them contribute to the overall grid control and power electronics research and advancement. Among the renewable energy systems, photovoltaic (PV) systems are the ones that make use of an extended scale of the advanced power electronics technologies. The specification of a power electronics interface is subject to the requirements related not only to the renewable energy source itself but also to its effects on the operations of the systems on which it is connected, especially the ones where these intermittent energy sources constitute a significant part of the total system capacity. Power electronics can also play a significant role in enhancing the performance and efficiency of PV systems. Furthermore, the use of appropriate power electronics enables solar generated electricity to be integrated into power grid. Aside from improving the quality of solar panels themselves, power electronics can provide another means of improving energy efficiency in PV and solar-thermal energy systems.

During 1991-2004 years, International Workshop on the Future of Electronic Power Processing and Conversion (FEPPCON) held four times with the support of IEEE Power Electronics Society. The main purpose is to outline the possibilities of development in different fields during the next period as a result of the discussions. At the last meeting held in Italy, the tendency to increase the role of Power Electronics during the next 25-30 years in the processes of energy conversion has been confirmed (Blaabjerg, 2005). Special attention is paid to the role of Power Electronics at a system energy conversion level, because it is not in the position to dictate the trends in the development of this level. Nevertheless, without the power electronics tools, future serious achievements in power processing are impossible. Therefore, the power electronics implantation at a system level at a system energy conversion level is an issue of the efforts of the specialists in this field (Agrawal, 2001). This, of course, imposes also some changes and adaptation towards Power electronics role also in the process of schooling of specialists paying attention mainly to multidisciplinary of Power Electronics. For example, a necessity of further tuition in electrochemistry, mechanics, physics (especially electromagnetic and thermal processes), etc, is outlined. Remote access to complex power electronics laboratory equipment and the possibility of remotely driving experiments and measurement is represented (Rodriguez, 2009). Power Electronics takes a significant part in the following systems: Generic Systems; Energy Storage; Power Systems, including Alternative Energy Supply; Automotive Systems (Bose, 2009).

Power electronics are used in wind turbines to convert variable voltages and frequencies produced by the generator to fixed voltages and frequencies compliant with an electrical grid with minimal losses. The power electronic system is based on a series of three-phase pulse width modulated (PWM) power modules consisting of insulated-gate bipolar transistor (IGBT) power switches and associated diodes that are soldered to a ceramic substrate and interconnected with wirebonds. Power electronics can generate thermal loads in the hundreds of watts/cm2, therefore the design of the packaging and cooling of the electronics is crucial for enhancing their energy efficiency and reliability. Without adequate heat removal, the increase in device temperature will reduce the efficiency of power electronic devices, leading to thermal runaway and eventual failure of the entire power electronic system. Furthermore, the increased temperatures can lead to failure of the packaging elements. Turbines utilizing these power electronics are often placed in harsh and inaccessible offshore environments; power electronic failures causing unscheduled maintenance lead to costly repairs. This paper will provide an overview of the fundamental package level mechanisms that can cause failures in the power electronic system. These include wirebond and lead fatigue, die attach fatigue, substrate cracking, and lead micro-voids. Attention will then be given to the reliability of a plastic-insert liquid cold plate used to manage the thermal loads from the power electronics.

2021 International Conference on Computer Technology and Power Electronics Jianning Wang1, Yuehua Zhao2 1College of Computer Science, Xi'an Shiyou University, China 2School of Computer Science and Telecommunication Engineering, Jiangsu University, ChinaE-mail: wjianning@xsyu.edu.cn, zhaoyuehua@ujs.edu.cn2021 International Conference on Computer Technology and Power Electronics were successfully held online from 30th to 31th of March 2021, Dalian, China. The conference was jointly organized and sponsored by Shaanxi Juxing Exhibition Co., Ltd and Juneng Electronic Technology Co., Ltd. The conference invited scholars and experts in the fields of the application of computer technology and power electronics from various universities to participate in the review and guidance of this conference. The conference focuses on the latest research fields such as "Computer Technology" and "Power Electronics", and aims to provide an international cooperation and exchange platform for experts, scholars and business managers in the fields of the application of computer technology and power electronics application to share their research achievements, discuss the key challenges and research directions of the development of this field, and jointly promote the industrialization cooperation and continuous innovation of international academic achievements. This collection of Proceedings compiles oral and paper presentations submitted by the authors and scrutinized by the Special Committee.The conference was scheduled to be held on March 30-31, 2021 in Dalian of China. In view of travel restrictions and indoor activities related to COVID-19, we were forced to move the conference online. Attendees were notified one month in advance that the on-site conference was changed to an online conference, and the time and order of the conference were determined. The online conference was held on the video conferencing software Tencent Meeting. The video conference was held on the original date. We divided the conference into main venue and sub-venue. The opening ceremony was held in the main venue and a speech was delivered by the invited speaker. After the main venue, we divided the invited 66 authors into 3 groups. Each author spoke for about 10-15 minutes on detailed material in the slides, with the same amount of time set aside for questions and discussion. The format of questioning and discussion was that after each author's introduction, the conference chairman and committee members asked and answered questions. At least one attendee could ask questions that will be answered by the speaker. This conference has brought together many excellent works and the latest ideas and concepts. New ideas have been provided in the fields of the application of computer technology and power electronics. For this, we have set up two awards, which were won by three authors. Due to the instability of the video conference software, we edited and retained part of the conference speech pictures and videos after the video conference. We put some screenshots of the conference on the official website for display.List of Organizing Committee, Scientific Committee, Editorial Committee, Invited Speakers, Organizing Institutions, Sponsors are available in this pdf.

The emerging trend of internet of things (IoT) and artificial intelligence (AI) technologies will bring about a major change in power electronics and create a new generation of the power electronics (Power Electronics 2.0). To enable the IoT- and Al-assisted Power Electronics 2.0, the integration of the sensors, the programmable hardware, and VLSIs for the controller into the power devices/modules is very important. In this paper, a 6-bit programmable gate driver IC with automatic optimization of gate driving waveform for IGBT is presented as the first step toward Power Electronics 2.0. In the proposed gate driver, the 6-bit gate control signals with four 160-ns time steps are globally optimized using a simulated annealing algorithm, reducing the collector current overshoot by 37% and the switching loss by 47% at the double pulse test of 300V, 50A IGBT. The gate driver is also applied to a half-bridge inverter, where the gate driving waveform is changed depending on the load current.

Dear Readers, Renewable Energy Systems and Power Electronics: Advances, Applications, and Integration, aims to provide a comprehensive resource on renewable energy systems and power electronics. Meeting the energy demand in a sustainable and environmentally friendly manner has become increasingly important in today's world. Therefore, renewable energy-based systems and power electronics technologies have garnered significant attention. This book consists of articles written by expert authors in the field. The authors address various topics, including solar energy, thin film deposition techniques, ultrasonic spray pyrolysis technique, dual active bridge DC/DC converters, and other important subjects. The book aims to serve as a valuable reference for students, researchers, and industry professionals who wish to grasp the fundamentals of these topics. The first section of the book provides a general overview of renewable energy sources. Solar energy, thin film deposition techniques, and other current topics are discussed in detail. Subsequently, the ultrasonic spray pyrolysis technique and its parameters, CDTE thin film solar cell structures and production methods, and other related subjects are examined. Additionally, the working principles and applications of emerging technologies such as Dye Sensitized Solar Cells (DSSCs) and Dual Active Bridge DC/DC Converters are also addressed. I believe that this book will provide readers with a broad perspective on renewable energy systems and power electronics. Each chapter contains detailed information to provide an in-depth understanding. Moreover, current research and applications are taken into account when discussing each topic. Lastly, I would like to express my gratitude to all the authors who contributed to the creation of this book. This work has been made possible through their willingness to share their knowledge and experience in the field of renewable energy systems and power electronics. In conclusion, I hope that this book will serve as a valuable resource for anyone interested in renewable energy systems and power electronics. Enjoy your reading. Best regards,