2020 DEIS Graduate Fellowship Winners

Every year, the IEEE Dielectrics and Electrical Insulation Society offers fellowships to eligible graduate students who are pursuing areas of work of interest to the society.

To learn more about the fellowship or apply for a future one, check out the Education portion of the DEIS website here.

Below are the 2020 fellows:

Yujie Zhu

Yujie Zhu was born in Jiangsu Province, China in 1995. He received his B.Sc. degree in electrical engineering from North China Electric Power University in 2017. Currently, he is a Ph.D. student in the Department of Electrical Engineering, Tsinghua University. From 2019 to 2020, he was a visiting student with Georgia Institute of Technology. His research interests include electrical insulation material design and charge transmission calculation. 

Project Title: Rational Design on High Temperature Polymer via Machine Learning

Abstract: In polymer design aspect, Prof. Rampi Ramprasad’s group in Georgia Institute of Technology has done a lot of related work and earn a lot of fascinating achievements.  The proposed work focuses on the electrical properties of High temperature polymer under different temperatures. By establishing a machine learning model for relationship between the high-temperature polymer fingerprint and the electrical properties under different temperatures, prediction for high-temperature polymers will be made via the collected laboratory experiment database. Several high-temperature polymers will be designed with desired properties for specific application like cables or polymer capacitors and will be synthesized for validation.

Alexios Ioannidis

Alexios I. Ioannidis (S’16) was born in Ptolemaida, Greece in 1993. He received the M.Eng. degree in electrical and computer engineering from Aristotle University of Thessaloniki (AUTh) in 2017. He is currently pursuing the Ph.D. degree in the High Voltage Laboratory, AUTh. His research is focused on computational electromagnetics for high voltage engineering applications and lightning protection; emphasis is given to the development of a stochastic lightning attachment model for assessing the lightning performance of power systems. In 2020 he was one of the winners of the IEEE IAS CMD Humanitarian Contest. He is a student member of IEEE and also a member of DEIS, EMC, IAS and PES.

Project Title: “Fractal-based modeling of surface discharges in advanced solid dielectrics”

Abstract: The proposed research work deals with the development of an innovative stochastic model for the dynamic simulation of the spatial growth of surface discharges in order to assess the surface dielectric strength of solid dielectrics. The surface discharge breakdown path will be recorded and modeled following a novel approach, which combines high voltage engineering with advanced techniques of computational electromagnetics; fractal-based simulation results will be validated through comparison with experimental data. This will allow for the prudent application of new insulation materials to modern power systems.

Ajith John Thomas

Ajith John Thomas (Graduate Student Member, IEEE) was born in Kerala, India. He received the M.E. degree in high voltage from CEG, Anna University, Chennai, India, in 2013. He is currently pursuing the doctorate degree in high voltage engineering with IIT Ropar, Rupnagar, India. His research interests include modelling and computation of breakdown fields under DC and polarity reversal and measurement techniques on the surface voltage measurements of HV power equipment.

Project Title: “Electric Treeing Breakdown Fields Incorporating Nonlinear Conduction under Steady State DC and Polarity Reversal”

Abstract: Until now, the needle-plane system was approximated with either spherical electrodes and/or cylindrical electrodes and has been addressed with the concept of field limited space charge. In this model, they advanced their analysis based on the assumption that critical field is fixed and because of the field limiting space charge, the electrode field will get saturated, even with the change in the applied voltage, and the same concept is reported in later works.

 From the above literatures, accurate computation of electric field and space charge with nonlinear conductivity (Field and Temperature Dependent) model seems to have not been addressed by using prolate spheroidal electrode geometry (particularly suitable to express the boundary geometry in a much accurate way which fits the needle-plane geometry) under dc and polarity reversal conditions until now. Modelling for the case of a needle-plane system is a bit involved with complex equations to be solved numerically. The proposed work and the computational strategy are explained as follows:

  • Prolate spheroidal electrode system, believed to be closer to needle-plane system, has been used for solving the governing differential equations (Poisson’s Equation, Current Continuity equation, thermal continuity equation and other field equations), numerically, for space charge and electric field distributions under DC and polarity reversal fields.
  • Unlike past works, in which, space charge at needle tip was assumed, either qualitatively or quantitatively, in this work, space charge formation is estimated using nonlinearity of material properties alone. A semi- semiempirical model of nonlinear conduction is used for this purpose.

Evangelos Staikos

Evangelos T. Staikos (S’20) was born in Thessaloniki, Greece in 1994. He received the M.Eng. degree in electrical and computer engineering from Aristotle University of Thessaloniki (AUTh) in 2018. He is currently pursuing the Ph.D. degree in the High Voltage Laboratory, AUTh. His research is focused on metal-oxide varistors characterization and modeling as well as surge protection of power systems. He is a student member of IEEE and also a member of DEIS and IAS.

Project Title: “Wide frequency modeling of metal-oxide varistors and advanced surge protection of smart devices”

Abstract: The main objective of the research proposal is to employ novel experimental and simulation techniques to develop electromagnetic transients models of metal-oxide varistors. The voltage-current characteristic will be obtained for a wide frequency range in the pre-breakdown and breakdown regions. With the aid of the developed models, the effectiveness of varistor-based surge protective devices will be investigated. The results of this work will form a basis for improving the surge protection of modern power systems and enhance the reliability of sensitive electronic and telecommunication equipment, commonly integrated into smart electronic devices.

Hanwen Ren

Hanwen Ren was born in Shanxi Province, China. He received his B.Sc. degree in electrical engineering and automation from North China Electric Power University in 2016. Currently he is a Ph.D. student supervised by Prof. Qingmin Li at North China Electric Power University. From 2019 to 2020, he was a visiting student in Tokyo City University supported by the State Scholarship Fund from the China Scholarship Council. In 2020, he received the Young Presentation Award at the IEEE ISEIM. His research interests mainly focus on high-precision measurement technology of space charge inside solid insulation.

Project title: “Development of space charge measurement technology with high spatial and temporal resolutions based on optical principles

Abstract: Space charge accumulation inside solid insulation can cause partial discharge, electric tree development and breakdown phenomena, which has become a key factor in indicating the insulating property. Compared with DC and low-frequency AC electrical environments that traditional power equipment usually bears, the insulation of high-power electronic equipment is subject to special electrical stresses such as high-frequency sine waves and PWM pulses. However, the traditional space charge measurement technologies used for DC voltages cannot be applied to these high-frequency special stresses. Therefore, this project aims to create a new measurement method based optical principles. The Terahertz wave generated by femtosecond pulse laser is used as the excitation pulses, which is applied to the sample to disturb the accumulated charge. The other probe light can get the charge information from the sampling sensor attached to the sample, which is then processed by optical detection system. The project is expected to develop a space charge measurement method with high spatial and temporal resolution.