A fault-tolerant control strategy for six-phase transverse flux tubular PMLM based on synthetic vector method

The six-phase transverse flux tubular permanent magnet linear motor (PMLM) has many advantages compared with conventional linear motors. However, the reliability of its drive system can still be influenced by power converter or machine faults. This paper presents a fault-tolerant control strategy for six-phase transverse flux tubular PMLM based on synthetic vector method when the machine has a single-phase open-circuit fault. The operation of six-phase transverse flux tubular PMLM is described as well as its basic mathematical model. Then, the principles of synthetic vector method are introduced. Based on these theories, the fault-tolerant control strategy is derived in detail under the single-phase open-fault condition. In addition, a fault-tolerant dual three-phase four-leg inverter's drive topology that can be applied under this faulted condition is proposed. Moreover, to implement the control algorithms proposed, a modified space vector modulation is presented. Both the finite-element simulation and MATLAB/Simulink simulation results illustrate the validity of the proposed fault-tolerant control as well as the associated control topology and space vector modulation.