Freewheeling Diode Current Under Open-Phase Fault in Field-Weakening Region of Multiple Three-Phase Drives
Source abstract
Abstract
Multiple three-phase machine drives are inherently fault-tolerant due to their multiphase structure; however, they remain susceptible to inverter-related faults. A common fault is the loss of gate signals in one inverter leg, resulting in an open-phase condition. Under such conditions, a reverse conduction path is established through the freewheeling diodes of the faulted leg, leading to uncontrolled freewheeling diode current generation. The resulting freewheeling diode current becomes particularly critical in the field-weakening region, when the back-EMF may exceed the DC-link voltage and a large reverse current can occur. This paper derives an analytical expression for real-time prediction of the freewheeling diode current in a triple three-phase surface-mounted permanent magnet synchronous machine drive. The method is applicable in both the constant-torque and field-weakening regions. The analytical prediction is validated through comparison with both experimentally measured and numerically simulated freewheeling diode current waveforms over a wide range of operating points, including no-load and loaded conditions. The results show that the proposed model accurately reproduces the envelope and conduction boundaries, while maintaining good agreement with simulations and measurements. The predicted current can be utilized in post-fault control, fault detection, and sensorless position estimation.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Multilevel Inverters and Converters · Sensorless Control of Electric Motors · Machine Fault Diagnosis Techniques
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, SI-1000 Ljubljana, Slovenia
Funding
Slovenian Research and Innovation Agency
References (32)
Show source-provided references
1. Slunjski, M. (2020). Control of a Nine-Phase Symmetrical PMSM with Reduced Rare Earth Material. [Ph.D. Thesis, Liverpool John Moores University].
2. Modular Stator Flux and Torque Control of Multi-Three-Phase Induction Motor Drives10.1109/TIA.2020.3022338 ↗
3. Son, D.K., Kwon, S.H., Kim, D.O., Song, H.S., and Lee, G.H. (2021). Control Comparison for the Coordinate Transformation of an Asymmetric Dual Three Phase Synchronous Motor in Healthy and Single-Phase Open Fault States. Energies, 14.10.3390/en14061735 ↗
4. Petrun, M., and Černelič, J. (2025). Sensitivity analysis of MTPA control to angle errors for synchronous reluctance machines. Mathematics, 13.10.3390/math13010038 ↗
5. Comparison of Two-Individual Current Control and Vector Space Decomposition Control for Dual Three-Phase PMSM10.1109/TIA.2017.2703682 ↗
6. Modular Vector Control of Multi-Three-Phase Permanent Magnet Synchronous Motors10.1109/TIE.2020.3026271 ↗
7. Fault-Tolerant Torque Controller Based on Adaptive Decoupled Multi-Stator Modeling for Multi-Three-Phase Induction Motor Drives10.1109/TIA.2022.3197547 ↗
8. Gholamian, M., Beik, O., and Arshad, M. (2024). A Review of State-of-the-Art Multiphase and Hybrid Electric Machines. Electronics, 13.10.3390/electronics13183636 ↗
9. Research on a 20-Slot/22-Pole Five-Phase Fault-Tolerant PMSM Used for Four-Wheel-Drive Electric Vehicles10.3390/en7031265 ↗
10. Frikha, M., Croonen, J., Deepak, K., Benômar, Y., El Baghdadi, M., and Hegazy, O. (2023). Multiphase Motors and Drive Systems for Electric Vehicle Powertrains: State of the Art Analysis and Future Trends. Energies, 16.10.3390/en16020768 ↗
11. Cui, S., Zhao, T., Du, B., and Cheng, Y. (2020). Multiphase PMSM with Asymmetric Windings for Electric Drive. Energies, 13.10.3390/en13153765 ↗
12. Scuiller, F., Charpentier, J.F., and Semail, E. (2010, January 1–3). Multi-star multi-phase winding for a high power naval propulsion machine with low ripple torques and high fault tolerant ability. Proceedings of the 2010 IEEE Vehicle Power and Propulsion Conference, Lille, France.10.1109/VPPC.2010.5729185 ↗
13. Hasoun, M., Afia, A.E., Chikh, K., Khafallah, M., and Benkirane, K. (2018, January 2–7). A PWM strategy for dual three-phase PMSM using 12-sector vector space decomposition for electric ship propulsion. Proceedings of the 2018 19th IEEE Mediterranean Electrotechnical Conference (MELECON), Marrakech, Morocco.10.1109/MELCON.2018.8379101 ↗
14. Bouyahia, O., Betin, F., and Yazidi, A. (2022). Fault-Tolerant Fuzzy Logic Control of a 6-Phase Axial Flux Permanent-Magnet Synchronous Generator. Energies, 15.10.3390/en15041301 ↗
15. Zabaleta, M., Jones, M., and Levi, E. (2017, January 11–14). A tuning procedure for the current regulator loops in multiple three-phase permanent magnet machines with low switching to fundamental frequency ratio. Proceedings of the 2017 19th European Conference on Power Electronics and Applications (EPE’17 ECCE Europe), Warsaw, Poland.10.23919/EPE17ECCEEurope.2017.8099167 ↗
16. Arbitrary Power Sharing Among Three-Phase Winding Sets of Multiphase Machines10.1109/TIE.2017.2733468 ↗
17. Diagnosis of Free-Wheeling Diodes in PMSM Drives Based on Residual Current Under Open-Circuit Faults10.1109/TIE.2024.3433476 ↗
18. Fault Diagnosis and Fault-Tolerant Control of PMSM Drives–State of the Art and Future Challenges10.1109/ACCESS.2022.3180153 ↗
19. Wang, B. (2025). Multiple 3-Phase Fault Tolerant Permanent Magnet Machine Drives: Design and Control, John Wiley & Sons, Incorporated. [1st ed.].10.1002/9781394252046 ↗
20. Uncontrolled generator operation of interior PM synchronous machines following high-speed inverter shutdown10.1109/28.806049 ↗
21. Modeling, Analysis, and Attenuation of Uncontrolled Generation for IPMSM-Based Electric Vehicles in Emergency10.1109/TIE.2019.2926049 ↗
22. Magnetization State Selection Method for Uncontrolled Generator Fault Prevention on Variable Flux Memory Machines10.1109/TPEL.2020.2992250 ↗
23. Analysis and Real-Time Calculation of Postfault Current of Standard Surface-Mounted PMSM Drives With Dysfunctional Power Switches10.1109/TPEL.2023.3277913 ↗
24. Chen, Z., Zhangliu, M., Chen, Y., Zhang, Z., and Luo, G. (2025, January 16–19). Sensorless Position Estimation for Dual Three-Phase PMSM Under Open-Circuit Fault Using Nonzero Diode Current. Proceedings of the 2025 28th International Conference on Electrical Machines and Systems (ICEMS), Busan, Republic of Korea.10.23919/ICEMS66262.2025.11317027 ↗
25. Postfault Sensorless Control of Three-Phase SPMSM Based on Unified Model of Diode-Through Residual Current Under Single-Phase IGBT Open-Circuit Fault10.1109/JESTPE.2025.3550466 ↗
26. Pyrhönen, J., Jokinen, T., and Hrabovcová, V. (2013). Design of Rotating Electrical Machines, Wiley. [1st ed.].10.1002/9781118701591 ↗
27. Hendershot, J.R., and Miller, T.J.E. (2022). Design Studies in Electric Machines, Motor Design Books LLC.
28. Hendershot, J.R., and Miller, T.J.E. (2010). Design of Brushless Permanent-Magnet Machines, Motor Design Books.
29. Nemec, M., Delavec, J., Vončina, D., and Ambrožič, V. (2025, January 20–22). Current Control in Multi-Coil PMSM. Proceedings of the 2025 IEEE 19th International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG), Antalya, Turkiye.10.1109/CPE-POWERENG63314.2025.11027172 ↗
30. Ambrožič, V., and Zajec, P. (2016). Električni Servo Pogoni, Slovensko Združenje Elektroenergetikov CIGRÉ-CIRED. [1st ed.]. (In Slovenian).
31. Stare, Ž., Fišer, R., Nemec, M., and Drobnič, K. (2025, January 25–26). Primerjava regulacijskih metod za vodenje večkratnih trifaznih strojev [Comparison of control methods for multiple three-phase machines]. Proceedings of the 34th International Electrotechnical and Computer Science Conference (ERK 2025), Portorož, Slovenia. (In Slovenian).
32. Lim, H., Hwang, J., Kwon, S., Baek, H., Uhm, J., and Lee, G. (2021). A Study on Real Time IGBT Junction Temperature Estimation Using the NTC and Calculation of Power Losses in the Automotive Inverter System. Sensors, 21.10.3390/s21072454 ↗