It is a great honor to introduce the eBook of COMPEL with selected extended papers presented originally at the 7th International Conference on Electromagnetic Field Problems and Applications (ICEF2016) held from September 18th to 20th 2016 in Xi'an, Shaanxi Province, China. The conference was co-sponsored by the China Electrotechnical Society, Chinese Society for Electrical Engineering and International COMPUMAG Society. The technical sessions and workshops were organized by State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University and State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace. This conference has provided a unique international forum for the exchange of information on state-of-the-art research in all aspects of developments and applications of electromagnetics, including both theoretical and applied research topics.Ever since the first ICEF took place in 1988, the conference has been held 6 times: in Beijing, Hangzhou, Wuhan, Tianjin, Chongqing and Dalian, respectively. The conference ICEF2016 received a total of 323 academic papers from 14 countries, and after rigorous review, a total of 289 papers including 5 invited papers were published in the conference proceedings. A total of 214 official delegates from 14 countries (China, the United States, Canada, the United Kingdom, France, Italy, Australia, Turkey, Russia, Slovakia, Poland, Japan, Korea and Thailand) attended the conference. About fifteen percent of the papers were selected by ICEF 2016 Editorial Board and COMPEL Guest Editors for publication in this eBook of COMPEL.