Improved Decoupling Control With Open Circuit Fault Suppression for Dual-Redundancy Permanent Magnet Synchronous Motor

The studied dual-redundancy permanent magnet synchronous motor (DR-PMSM) can realize fault tolerant control (FTC) by isolating the faulty winding or inverter. However, there is a strong coupling between the two sets of windings of DR-PMSM, which increases the control difficulty. Besides, when an open circuit fault (OCF) occurs, there will be large torque fluctuation before the faulty winding is cut off. In order to eliminate the control coupling and protect the DR-PMSM under OCF. First, the article analyzed the harmonic distribution and coupling of DR-PMSM, indicating the limitation of current methods. Then, the article proposed an improved decoupling control, which utilized the inherent coupling of DR-PMSM to suppress OCF. The difference between the original decoupling control and the improved decoupling control is analyzed and validated. Finally, the article proposed the post-fault process of DR-PMSM to eliminate the OCF effect, which is implemented with the redundancy of DR-PMSM. The article proposed an entire FTC plan for DR-PMSM, including decoupling, OCF suppression, and OCF elimination.