20.500.12556/RUL-183619 Freewheeling diode current under open-phase fault in field-weakening region of multiple three-phase drives 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. multiple three-phase machine open-phase fault field-weakening freewheeling diode current uncontrolled generation večfazni stroj napaka v močnostnem pretvorniku napaka odprtih stikal slabljenje polja tok prostoročne diode true false true Angleški jezik Slovenski jezik Članek v reviji 2026-06-16 12:22:34 2026-06-16 12:22:43 2026-06-17 04:11:02 0000-00-00 00:00:00 2026 0 0 28 str. issue 12, art. 5994 Vol. 16 Jun.-2 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 621.313/.314 2076-3417 10.3390/app16125994 281786371 applsci-16-05994-v2.pdf applsci-16-05994-v2.pdf 1 7B42225A6EAEFB61DD2DFBD02D367CA3 8e0b2a3dfce0501ce1a8f511c6dbfcfa6ef5c919b2f9204e61bc29fe43eec02e 5a565f54-696d-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235732 https://www.mdpi.com/2076-3417/16/12/5994 1 4334ad36-696d-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235731 Fakulteta za elektrotehniko 0 0 0