A two-level inverter followed by a DC-link referenced output filter is a promising solution for high-speed low-voltage drive systems. A limitation of this power electronics topology, however lies in the high current ripple and hence additional losses occurring within the filter inductors. This shortcoming can be addressed by means of an appropriate modulation technique. This paper details two new modulation strategies, tailored to the specific characteristics of three-phase inverters with DC-link ref-erenced output filter, utilizing the instantaneous common-mode (CM) voltage as a degree of freedom, in order to decrease the output inductor’s current ripple. It is deduced that a constant(DC) CM injection modulation(DCCMM) or an AC CM injection modu-lation(ACCMM) with arbitrarily large amplitude yields the best performance depending on the operating point. The CM pattern that minimizes the inductor current ripple envelope results from the combination of the two schemes and constitutes the optimal CM injection modulation(OCMM). Furthermore, the proposed modulation schemes are tested on a 300 W hardware demonstra- tor driving a 300 krpm custom designed motor, where a reduction of the total inverter losses of up to 11% is observed.

Compact, light weight and efficient Power Electronic Building Blocks are seen as fundamental components of future More Electric Power Systems, e.g. More Electrical Aircraf t. Core el-ements supporting the trend are power modules employing solely SiC MOSFETs. In order to take advantage of the high switching speed enabled by SiC, novel modules concepts must be investigat-ed. For example, low inductance planar interconnection technolo-gies, integrated buffer capacitors and damping networks are pos-sible solutions to mitigate switching overvoltages and oscillations at the switching node occurring for conventional modules. In this paper, the analysis and the design of a novel ultra-low inductance 1200 V SiC power module featuring an integrated buffer-damping network are discussed. The power module is first described and characterized with impedance measurements. Afterwards, a gen-eral optimization procedure for the sizing and the selection of the integrated components is presented and measurements are per-formed to verify the analysis and to highlight the improvements of the proposed solution.

The Power Sources Manufacturers Association(PSMA) currently publishes an updated Power Technology Roadmap(PTR) every two years. This paper describes the methodology used and the key findings captured in the tenth edition which was published in March 2017. Applications driving the roadmap needs are presented along with the direction of technology advancement in components, power supplies and converters. Emerging technologies which promise the potential of further advancement, but are not yet proven, are also discussed.

As an important development direction of power electronic systems, the integration technologies can bring many benefits, such as size reduction, reliability improvement, cost saving and so on. With the continuous development of power semiconductor devices, especially the emergence of wide band-gap devices, more advanced integration technologies are needed. This paper reviews the state-ofart integration technologies, including active and passive integration technologies. Active integration technology is reviewed in terms of the interconnect, packaging material, packaging structure, and module integration. Passive integration technology is reviewed from the aspects of magnetic integration technology, electromagnetic integration technology, and low-temperature cofired ceramic(LTCC) technology. Higher-level integration technologies, namely power supply on chip(PwrSoC) and power supply in package(PwrSiP), are also investigated, which are mainly used in low power applications.

In modern mobile communication systems, spectral efficient modulation formats have been widely used, which results in the envelope of the radio frequency(RF) signal is variable and having large peak to average power ratio(PAPR). In order to amplify the RF signal without distortion, the linear power amplifier(LPA) is adopted, which is less efficient when powered by constant voltage. Three popular techniques, i.e., Doherty, envelope elimination and restoration(EER), and envelope tracking(ET) techniques, to greatly improve the efficiency of the power amplifiers are analyzed and compared in this paper, and it is shown that the ET technique is the most suitable for future mobile communication systems. In the ET systems, the ET power supply is the key equipment, which dominates the system efficiency. With the development of the mobile communication systems, the bandwidth and the PAPR of the envelope signals are increasing rapidly, which pose severe challenges on the design of the ET power supply. This paper summarizes and sorts the ET power supplies in the literatures, and a detailed comparison is presented to guide the selection of ET power supplies for different applications. Finally, the methods, including soft-switching, slow envelope, and band separation are proposed for further increasing the efficiency of the ET power supply.

Energy storage systems(ESSs) can improve the grid’s power quality, flexibility and reliability by providing grid support functions. This paper presents a review of distributed ESSs for utility applications. First, a review of the energy storage market and technology is presented, where different energy storage systems are detailed and assessed. Then, ESS grid support functions are presented and seven types of functions are described. Finally, the power electronic converters for distributed ESSs are reviewed and the corresponding features and performances are evaluated. The main objective of this paper is to provide an updated reference regarding ESSs for utility applications to researchers and practitioners in the field of power electronics.

The subsea industry has become more predominant in recent years because of the discovery of a significant number of new oil and gas fields located in deep water, a term often used to describe offshore projects located in water depths greater than 600 feet. In order to extract oil and gas, a large number of electrical systems need to be deployed at the seabed. Many of these electrical systems need high-reliability power grid and power control units located on the seabed to minimize downtime. Power system and power electronics play a major role in providing the required and reliable power to various electrical systems. But there are many challenges for deploying power components under the seabed. This paper presents the challenges and the requirements of power system components operating in subsea environment, use of power electronics for efficient transmission of power from the offshore platform or from the shore to the subsea electrical loads; variable speed drive systems; and research areas related to power electronics for subsea electrical systems.

The objective of this paper is to provide an overview of emerging technologies for modular power converter architectures for electric vehicles. Nowadays, the most common electrical drive-train architecture exhibits one single inverter which is directly tied to the battery. As a consequence, only one high-voltage battery module can be applied and the dc-link voltage of the inverter and its apparent power rating is directly dependent on the available battery voltage. To overcome this restriction, modern power converter architectures with a higher degree of freedom have been proposed. These architectures exhibit modular dc-dc converters to allow different battery technologies to be linked to drive inverters operating independently from each other. To make this development feasible, new components and technologies are evolving which enhance the efficiency over mission cycles while ensuring further integration of the power-converter architectures. Wide-bandgap power semiconductors enable high switching frequencies and miniaturization of passive devices. Smart topology enhancements and control methods allow a significant loss reduction, in particular at light loads, resulting in a higher efficiency of the drive train over the entire driving cycle. Highly integrated bidirectional battery charger systems with intelligent charging strategies inhibit battery degradation and provide opportunities for grid stabilization. It is demonstrated how these technologies are realized and implemented to contribute to the development of future electric vehicles.

WITH this editorial, we sincerely welcome our readers to the brand-new publication — CPSS Transactions on Power Electronics and Applications(CPSS TPEA). It is sponsored and published by China Power Supply Society (CPSS) and technically co-sponsored by IEEE Power Electronics Society(IEEE PELS). CPSS was founded in 1983 and has been the only top-level national academic society in China that solely focuses on the power supply/power electronics area. In the past 30-plus years CPSS has dedicated to provide to its members, researchers, and industry engineers nationwide with high quality services including conferences, technical training, and various publications, and this in deed has helped the society build up its membership rapidly, which now totals up to more than 4000 individual members plus 500 enterprise members. The fast growth of membership in turn compels CPSS to always work out better services for its members, one of which being the open-up of this periodical — a new journal in English language as a publication platform for international academic exchanging. This of course needs to be done through international cooperation, and that’s why IEEE PELS is tightly involved, being the premier international academic organization in power electronics area and one of the fastest growing technical societies of the Institute of Electrical and Electronics Engineers(IEEE). To fulfill the publishing need of the fast-developing power electronics technology worldwide is a more important purpose of launching this new journal. So far there are only 3 or 4 existing journals which are concentrated on power electronics field and have global reputation. For quite a few years people in the international power electronics community have had the feeling that, the existing journals have not even come close to meeting the huge demand of global academic and technology exchanges. E.g., the two existing IEEE power electronics journals, i.e. IEEE Transactions on Power Electronics(IEEE TPEL) and IEEE Journal of Emerging and Selected Topics in Power Electronics(IEEE JESTPE), now publish about 1000 papers a year, which is under a very low paper acceptance rate of around 25%, but still have a backlog of about one year for the newly accepted papers to finally appear in printed form to the public. The addition of this new dedicated journal would be an ideal improvement to fulfill such a tremendous need. The booming of publishing need really is an indicator of how fast power electronics has been developing in recent years. Innovations have been continuously coming up from component(both active device and passive device), module, circuit, converter, to system level, covering different technical aspects as topology or structure conceiving, modeling and analysis, control and design, and measurement and testing. New issues and corresponding solutions have been continuously presenting as the applications of power electronics prevail horizontally in almost every area and corner of human society, from industry, residence and commerce, to transportations, and penetrate vertically through every stage of electric energy flow from generation, transmission and distribution, to utilization, in either a public power grid or a stand-alone power system. I personally believe that we are entering a world with “more electronic” power systems. The prediction around 30 years ago, that power electronics one day will become one of the major poles supporting the human society, is coming into reality. And I also believe, that power electronics is going to last for long time as an important topic since it is one of the keys to answer a basic question for human society, which is how human can harness energy more effectively and in a manner friendlier to both the user and the environment. Therefore, I assume that there is probably no better fitting as for CPSS TPEA to publish its first few issues under a special topic about the developing trends of power electronics. We have invited a group of leading experts in different areas of power electronics to write survey/review papers or special papers with review/overview nature to some extent. To publish in a timely and regular style, we organize this inaugural Special Issue into 5 different parts. Part 1, 2, 3 and 4 were published in the December issue last year and previous issues of this year respectively, Part 5, appearing in this December issue, is the last part of the inaugural Special Issue. In Part 5 we are honored to have 6 invited papers. The first four address four recently hot or emerging application areas of power electronics, all with reviews on the state-of-the-arts and discussions about future developing trends, whereas the next two provide overviews on specific technologies, such as components, packaging and integration, and power converters etc., for almost all kinds of application areas. We begin with a paper on the power electronics applications to electric vehicles. It is authored by Dr. Rik De Doncker and his research group from RWTH Aachen University. It provides an overview of emerging technologies for modular power converter architectures for electric vehicles. Technologies like wide-bandgap power semiconductors, smart topology enhancements, control methods, and highly integrated bidirectional battery charger systems with intelligent charging strategies are all discussed. The second paper is about power electronics applications to the electrification of subsea systems. It is written by Dr. Kaushik Rajashekara and his research group from the University of Houston. It presents a summary on the requirements and challenges in the power distribution and conversion for subsea systems, which have become more predominant in recent years. The issues that are discussed include power architectures, power system components, power converters and motor drives, and health analytics and fault handling. The third paper is regarding the power electronics applications to distributed energy storage systems(ESS) for electric power utilities. It is written by Dr. Liuchen Chang and his research group from the University of New Brunswick. A review of the energy storage market and technology is presented, with a classification of ESS grid support functions, followed by a detailed evaluation on the power electronic converters for distributed ESSs. The fourth paper introduces power electronics applications to mobile communication systems. It is written by Dr. Xinbo Ruan and his research group from Nanjing University of Aeronautics and Astronautics. The paper sorts, compares and summarizes all different kinds of envelope tracking(ET) power supplies for different specific modern mobile communication systems. Ideas including soft-switching, slow envelope, and band separation are also proposed as possible solutions to further improve the efficiency of the ET power supplies. The fifth paper is written by Dr. Laili Wang, Dr. Xu Yang and their students from the Power Electronics and Renewable Energy Center at Xi’an Jiaotong University, discussing integration technologies for power electronics systems. It reviews and evaluates the state-of-art integration technologies, including an active integration part which covers interconnection, packaging structure, and packaging material for power semiconductor devices, and a passive integration part which encloses magnetic integration, electromagnetic integration, and low-temperature co-fired ceramic(LTCC) technology. Last but not least, the sixth paper is written by Dr. Conor Quinn and Mr. Dhaval Dalal, both representing the Power Sources Manufacturers Association(PSMA). PSMA publishes a technical report called Power Technology Roadmap (PTR) every two years, supplying an in-depth review on the recent technological developments related to power sources. This paper summarizes the methodology used and the key findings captured in the most recent edition which was released in March 2017. I believe there is no better arrangement than having a paper like this, reflecting visions of so many technological leaders from power electronics industries, to conclude this Part 5 and the whole Special Issue as well. I’d like to thank the authors of all these 6 invited papers. It’s their high-quality contributions that finally leads to the launching of this new journal. I’d like to thank Dehong Xu, President of CPSS, who in 2015 initiated the idea of publishing the new journal and since then has been persistently supporting my work as the founding Editor-in-Chief. I’d also like to thank Jiaxin Han, Secretary General of CPSS, Jan A. Ferreira, President of IEEE PELS, 2015-2016, Don F. D. Tan, President of IEEE PELS, 2013-2014, and Frede Blaabjerg, IEEE PELS Vice President for Products, 2015-2018, who form the CPSS and IEEE PELS Joint Advisory Committee for our new journal with Dehong Xu and myself. Other IEEE officers and leading staffs like Dushan Boroyevich, PELS President, 2011-2012, Alan Mantooth, PELS President, 2017-2018, Mike Kelly, PELS Executive Director, and Frank Zhao, Director of China Operations, IEEE Beijing Office, just to name a few, also provided continuous support and constructive advices. My earnest thanks also go to the CPSS Editorial Office led by Lei Zhang, Deputy Secretary General of CPSS, for their wonderful editing work. It would not have been possible to create a new journal in such a short time without their efforts. I’d like to finally thank all the members of the Executive Council of CPSS and particularly the leaders of Chinese power electronics industry. They always firmly stand behind CPSS TPEA and ready to help whenever needed.