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The Laboratory for High Power Electronic Systems (HPE) at the Department of Information Technology and Electrical Engineering of ETH Zurich conducts internationally leading research on power electronic converter systems. These systems are essential for future energy distribution, integrating renewable energy sources, and applications in electric mobility. Additionally, HPE focuses on solid-state pulse modulators for medical applications (e.g., computer tomography, cancer treatment) and accelerators (CERN). We are now recruiting a Ph.D. candidate (100%) for a new research project on future electrical vehicle drive systems, focusing on modelling and optimizing highly efficient drive systems based on GaN devices.
We are seeking individuals with outstanding academic credentials and a high level of motivation to engage in doctoral research on developing highly efficient future drive systems for electric vehicles with a battery system voltage exceeding 1 kV. To achieve high efficiency across a wide operating range, it is necessary to evaluate, model, and optimize different four-level inverter topologies and suitable modulation schemes for drive systems. Considering a wide operating range is crucial, as the inverter is directly connected to the medium-voltage battery, which varies with the state of charge. Additionally, the drive system often operates at relatively low power/torque levels compared to nominal power/torque, necessitating consideration of partial load operation during the design phase.
The efficiency increase will be achieved using optimized 4-level inverter topologies, which reduce losses in the electrical machine due to lower ripple currents. Additionally, the switching frequency and modulation will be optimized for various operating points. One disadvantage of 4L inverters is the higher number of switches, resulting in higher costs and space requirements. Therefore, the trade-off between lower inverter/motor losses due to the 4L topology and higher system costs/complexity will be evaluated in the project.
The optimal design will be identified based on comprehensive models and an optimization procedure considering typical operation profiles of electric vehicles. The optimization will include various 4L topologies, modulation schemes, a wide switching frequency range, and different motor types, as well as basic control strategies to identify the best topology and optimal operating parameters for different operating points. Furthermore, switching loss models for new wide band gap enhancement mode GaN HEMT devices will be investigated to determine switching losses for different operating points (voltage, current & temperature). Models for losses in the electric machine, particularly focusing on HF ripple, will also be developed. Finally, the optimized design will be validated with a prototype system.
The candidate must have a diploma/M.Sc. degree in electrical engineering with excellent grades, fundamental knowledge of power electronic converter systems, good communication skills, fluency in English, and a willingness to fully commit as part of an international team. Additionally, you should be interested in the detailed investigation and modeling of converter topologies, modulation schemes, and losses in electrical machines.
Our laboratory offers a challenging and scientifically exciting full-time position in a dynamic, international team at one of the world's leading technical universities. We strongly encourage participation at international conferences and offer a competitive salary, excellent benefits, and outstanding research and laboratory facilities for experimental work. In this project, lasting approximately 3-4 years, you will also cooperate with industry partners.
In line with our values, ETH Zurich encourages an inclusive culture. We promote equality of opportunity, value diversity, and nurture a working and learning environment where the rights and dignity of all our staff and students are respected. Visit our Equal Opportunities and Diversity website to learn how we ensure a fair and open environment that allows everyone to grow and flourish.
We look forward to receiving your online application with the following documents:
Please note that we exclusively accept applications submitted through our online application portal. Applications via email or postal services will not be considered.
Further information about the Laboratory for High Power Electronic Systems (HPE) can be found on our website. For further information, please contact Prof. Dr. Jürgen Biela, Tel +41 44 632 69 22 or email jbiela@ethz.ch (no applications).
ETH Zurich is one of the world’s leading universities specializing in science and technology. We are renowned for our excellent education, cutting-edge fundamental research, and direct transfer of new knowledge into society. Over 30,000 people from more than 120 countries find our university to be a place that promotes independent thinking and an environment that inspires excellence. Located in the heart of Europe, yet forging connections all over the world, we work together to develop solutions for the global challenges of today and tomorrow.