Decoupled Design of Fault Tolerant Control for Dual Three-phase IPMSM with Improved Memory Efficiency and Reduced Current RMS

Fault tolerance is critical to real-time control of dual three-phase interior permanent magnet synchronous machine (IPMSM). This paper proposes an efficient decoupled design for fault tolerant control (FTC) of dual three-phase IPMSMs to improve the average torque and minimize current root mean square (RMS) for torque ripple and loss reduction under the open-phase fault. Specifically, FTC design is divided into two subtasks to derive the FTC strategy with simplified design, in which the two subtasks are the fundamental current design and the harmonic current design. The optimal current solution to FTC is derived in a memory and computation efficient way. The proposed solution can achieve better transient performance and reduce the current RMS for FTC, which is critical to practical applications with dynamic changing loads. In comparison with existing methods, the proposed FTC can effectively reduce the request of memory and computation resources from the drive system. Extensive experiments and comparisons are conducted to evaluate the proposed FTC on a laboratory dual three-phase IPMSM.