Master’s Thesis: Evaluation of Soft-Switching Topologies for High-Efficiency Power Electronics

Fast-switching SiC and GaN devices offer opportunities for efficient three-phase inverters, but hard switching can increase losses, device stress and electromagnetic interference. This thesis will assess whether soft-switching topologies can improve efficiency while meeting practical requirements for control, waveform quality and scalability. The work contributes to RISE’s research on modular power converters within the European Moore4Power project.

The assignment

• Survey soft-switching methods and their application to three-phase inverters, including ARCP, resonant DC-link, ZVT and TCM approaches.
• Establish a shared inverter specification and develop a hard-switched, two-level reference model.
• Select and dimension soft-switching circuits, including resonant elements, auxiliary switches, semiconductor devices and commutation timing.
• Create simulation models using PLECS, MATLAB/Simulink and/or SPICE, with SiC and GaN loss models derived from device datasheets.
• Verify ZVS or ZCS operation throughout the fundamental period and evaluate efficiency across loads, power factors, switching frequencies and device technologies.
• Quantify conduction, switching, auxiliary-circuit and passive-component losses, and compare waveform distortion, device stress, component count and control complexity.
• Recommend a topology suitable for a modular, scalable three-phase inverter and, if time permits, investigate load-adaptive control or combined hard- and soft-switching strategies.
• Deliver validated simulation models, a quantitative comparison, a thesis report and an oral presentation.

Who we are looking for

• Final-year master’s student in Electrical Engineering, Electric Power Engineering, Mechatronics or a related discipline.
• Strong understanding of power electronics and experience with circuit simulation tools such as PLECS, LTspice/PSpice or MATLAB/Simulink.
• Good command of written and spoken English.
• Analytical, independent and able to communicate effectively.

What we offer

• Supervision from a RISE researcher.
• Access to licences for the required simulation software.
• Participation in Moore4Power, a European research collaboration involving more than 60 industrial and academic partners.
• Compensation under RISE’s guidelines for thesis work.

Practical details

Full-time master’s thesis worth 30 ECTS, starting in January 2027. Based in Göteborg and intended for one or two students. Application deadline: 6 November 2026. Selection and interviews take place on an ongoing basis during and after the application period. Supervisor and contact: Lakshmi Priya Gandla, lakshmi.priya.gandla@ri.se. The student’s university will appoint the examiner.