Efficiency Evaluation and Transient Thermal Performance of PMSM under Various Duty Cycles by Experimental Analysis and Model Validation
Umar, Muhammad (2026)
2026
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2026-02-10
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202602092400
https://urn.fi/URN:NBN:fi:tuni-202602092400
Tiivistelmä
Thermal analysis plays an essential role in assessing the reliability and operational performance of electric machines, as excessive heat can lead to reduced efficiency, material degradation, and a shortened operational lifetime. This aspect is particularly critical in permanent magnet synchronous machines (PMSM), where elevated temperatures may cause demagnetisation of the permanent magnets.
This thesis aims to investigate the efficiency and transient temperature rise in a PMSM primarily designed for continuous operation duty (S1), while examining the machine’s performance under the short time duty (S2) and intermittent duty cycle (S3) as well. Simplified steady state and transient thermal models were developed and solved analytically using the lumped parameter thermal network (LPTN) technique.
A real test setup was incorporated in such a way that two identical machines were aligned and mechanically coupled in a back-to-back motor-generator configuration. These two machines were driven and controlled by inverters using closed loop control, such that the motor drew power from the grid, while generator (acting as a load machine) supplied the power back to the grid through an active front end. The temperature of the PMSM under test was closely monitored and recorded during the experimentation phase, and the results were compared to the analytical predictions obtained from the LPTN models. The findings showed a strong consistency between the experimental data and the model estimations.
These findings provide valuable insights into the thermal behaviour and efficiency of a PMSM under S1, S2, and S3 duty cycles. The outcomes will support research and development teams in refining thermal management strategies, serve as a tool for early stage thermal assessment, and contribute to the development of PMSMs for extended applications in the future.
This thesis aims to investigate the efficiency and transient temperature rise in a PMSM primarily designed for continuous operation duty (S1), while examining the machine’s performance under the short time duty (S2) and intermittent duty cycle (S3) as well. Simplified steady state and transient thermal models were developed and solved analytically using the lumped parameter thermal network (LPTN) technique.
A real test setup was incorporated in such a way that two identical machines were aligned and mechanically coupled in a back-to-back motor-generator configuration. These two machines were driven and controlled by inverters using closed loop control, such that the motor drew power from the grid, while generator (acting as a load machine) supplied the power back to the grid through an active front end. The temperature of the PMSM under test was closely monitored and recorded during the experimentation phase, and the results were compared to the analytical predictions obtained from the LPTN models. The findings showed a strong consistency between the experimental data and the model estimations.
These findings provide valuable insights into the thermal behaviour and efficiency of a PMSM under S1, S2, and S3 duty cycles. The outcomes will support research and development teams in refining thermal management strategies, serve as a tool for early stage thermal assessment, and contribute to the development of PMSMs for extended applications in the future.