Conventional predictive control (PC) has been employed for machine drives due to good dynamic response and easy implementation. However, the disturbance caused by machine parameter mismatch is one of main barriers to its widespread application. In order to deal with this issue, this work proposes a novel model-free predictive current control (MFPCC) for surfaced permanent magnet synchronous machines (SPMSM). The contribution of this work is that a novel extended state observer (ESO) is proposed and the proposed MFPCC only utilizes the input and output knowledge of the plant without using any machine parameter in controller, which can effectively suppress the disturbances. In addition, the effect of the initial machine inductance parameter mismatch on the conventional ESO of MFPCC is analyzed in detail. The proposed MFPCC is validated and compared against three methods, namely PC without ESO, PC using ESO, and MFPCC using ESO. The experimental results have been carried out to verify the effectiveness of the proposed MFPCC.

This paper presents a fault-tolerant sensorless control strategy based on a wide-speed strong-robustness sliding mode observer (SMO) for a new five-phase fault-tolerant fractional-slot concentrated-winding interior-permanent-magnet (FTFSCW-IPM) motor, in which the motor drive system has a high reliability. The designed motor possesses a high fault-tolerant capacity. Also, the fault-tolerant space vector pulse width modulation (SVPWM) strategy and the sensorless control are adopted to further improve the fault tolerance of the control system. Moreover, unlike the existing SMO, the proposed SMO algorithm can achieve enhanced low system chattering, estimated accuracy at low speed, as well as strong robustness to motor parameters, fault and load disturbance. Numerical simulations and experiments with a 2-kW five-phase FTFSCW-IPM motor are carried out. The results verify the feasibility and effectiveness of the proposed fault-tolerant sensorless method adopted by the FTFSCW-IPM motor.

High reliability is important in motor driving system for electric vehicle applications. In this paper, a fault-tolerant direct torque control for a five-phase fault-tolerant fractional-slot concentrated-winding interior-permanent-magnet (FTFSCW-IPM) motor under the open-circuit condition of a single phase is proposed, in which an analogous three-phase space vector pulse width modulation (SVPWM) control strategy is adopted. The DTC system for the five-phase PM motor based on healthy SVPWM has several advantages of improved currents and low torque and flux ripples. To achieve the fault-tolerant operation of the SVPWM-DTC system, an analogous three-phase SVPWM strategy is proposed. The proposed SVPWM fault-tolerant control scheme is achieved by the division of six sectors and the reconfiguration of six equal nonzero voltage vectors, which is quickly computed and easily realized. In addition, based on a 2-kW FTFSCW-IPM motor prototype, the good performances of the proposed fault-tolerant drive are validated by both simulations and experiments, in which the average torque and low torque ripple during fault can be maintained. Finally, the dynamic performances under healthy and fault-tolerant conditions are measured. The results show that the proposed analogous three-phase SVPWM control can offer good dynamic performance, which is comparable to the healthy SVPWM.

In this article, an improved inertia disturbance suppression method is proposed for permanent magnet synchronous motor (PMSM) based on disturbance observer and two-degree-of-freedom PI controller (DOB-2DoFC). The DOB-2DoFC is proposed to enhance the speed control performance with variation of inertia caused by load changing. The traditional two-degree-of-freedom controller (2DoFC) is first introduced and the influence of inertia disturbance on 2DoFC is analyzed. Then, the disturbance observer (DOB) is designed to combine with 2DoFC for inertia disturbance suppression. Furthermore, the discretization of DOB-2DoFC is implemented and the impact of discretization is also analyzed, in the meanwhile, the parameters of DOB- 2DoFC is designed based on the premise of stability and good speed control performance. With the designed parameters, better speed control performance can be maintained without tuning any controller coefficients even when the actual inertia is 20 times the controller inertia. Finally, the effectiveness and the correctness of the proposed DOB-2DoFC are verified with experiments on a 400 W PMSM drive platform in two modes.

This paper proposes and compares two new fault-tolerant fractional-slot concentrated-winding interior permanent magnet (FTFSCW-IPM) motor open-end winding (OW) drive systems for electric vehicles. The proposed FTFSCW-IPM motors possess the merits of high efficiency, high power density, and strong fault-tolerant capacity. Also, to further improve the reliability of control system, an OW dual inverter drive system is adopted. Furthermore, to better and clearer illustrate the advantages and disadvantages of multiphase machine system, the comprehensive comparison of three-phase and five-phase FTFSCW-IPM motor OW drive systems is carried out from the perspective of motor design and control system. The topologies and the features of the proposed two FTFSCW-IPM motors are analyzed, and the static characteristics are investigated and compared by using the finite-element analysis (FEA). Then, the evaluation of their OW drive system performance is conducted and compared by the simulation based on the MATLAB/Simulink. Finally, the FEA and simulation results are validated by experiment on both prototypes.

Traditional ultralocal model-based predictive current control (UL-PCC) method has strong robustness on current control; however, the UL-PCC still relies on inductance to design the controller gain, which really deteriorates its robustness on parameter. To solve it, a parameter-free ultralocal model-based deadbeat predictive current control (PF-DPCC) method using finite-time gradient method (FGM) is proposed in this article for permanent magnet vernier motor (PMVM) drives. The UL-PCC is first modified considering rotor speed without any extra parameter. Then, the impact of initial controller gain on robustness is analyzed and an extreme low duty-cycle current signal which has negligible impact on current is injected to estimate the controller gain of PF-DPCC adaptively on the basis of the deadbeat concept and the FGM. Hence, all motor parameters are not required in advance and the initial controller gain can be set as 1 directly. Then, the robustness can be effectively improved and the dependence on initial value of controller gain can be eliminated. Finally, the effectiveness and the correctness of the proposed PF-DPCC are experimentally verified on a 400-W PMVM drive platform.