New Publication: Detecting Inter-Turn Short Circuits in Dual-Rotor Air-Cored PMSGs with Series-Connected Stator Coils
We are pleased to announce the latest MEGA WAVE PTO project research, presented at the 2025 IEEE Symposium on Diagnostics for Electric Machines, Power Electronics and Drives (SDEMPED). This study investigates inter-turn short circuit (ITSC) faults in dual-rotor, air-cored permanent magnet synchronous generators (PMSGs) with series-connected stator coils, a key focus for improving reliability in offshore renewable energy systems.
About the research
Detecting inter-turn short circuits (ITSCs) remains a significant challenge for direct-drive PMSGs in wave, tidal, and wind energy applications. This study examines ITSCs in a dual-rotor, air-cored PMSG with series-connected coils, using a validated finite element analysis (FEA) model to analyse electromagnetic performance under healthy and faulty conditions.
To understand how ITSCs affect generator operation, the study investigated variations in contact resistance and short-circuit ratios to derive fault-induced current signatures. Conventional current-based detection methods—Motor Current Signature Analysis (MCSA) and the Extended Park’s Vector Approach (EPVA)—were evaluated and found to be less sensitive for low-severity faults, which could lead to misdiagnosis. These results highlight the need for complementary monitoring strategies to enable early fault detection and enhance the reliability and efficiency of offshore renewable energy systems.
Key contributions
Analyses ITSC detection in dual-rotor, air-cored PMSGs with series-connected stator coils
Develops and validates a finite element analysis (FEA) model under healthy and faulty conditions
Investigates fault-induced current signatures and the impact of contact resistance and short-circuit ratio
Evaluates limitations of conventional current-based detection methods (MCSA, EPVA)
Guides developing complementary monitoring strategies for early fault detection
Publication details
Title: Analysis and Diagnosis of Inter-Turn Short Circuit Faults in Dual-Rotor Air-Cored PMSG – Series Connected Stator Coils
Authors: Alexandros Sergakis, Nikolaos Gkiolekas, Markus Mueller, Konstantinos N. Gyftakis
Published in: 2025 IEEE Symposium on Diagnostics for Electric Machines, Power Electronics and Drives (SDEMPED)
Conference Dates: 24–27 August 2025, Dallas, TX, USA
DOI: 10.1109/SDEMPED53223.2025.11154265
Why this research matters
Early detection of inter-turn short circuits is essential for the safe, efficient, and long-lasting operation of permanent magnet generators in offshore environments. This study's findings provide a foundation for improved condition monitoring and fault-tolerant designs, contributing to more reliable and resilient wave and tidal energy systems under the MEGA WAVE PTO project.
For more updates on our research, stay tuned to the News Section of the MEGA WAVE PTO website.
