An active disturbance rejection control (ADRC) controller using phase-locking loop observer (PLLO) is proposed in this paper to improve the disturbance rejection property of speed control system. Firstly, to simplify the comparison with other controllers, a universal speed controller design method based on disturbance estimation is employed, and a unified expression for different controllers is presented. Then, several common speed controllers are compared with each other, and two PLLO based ADRC controllers are presented. After that, considering the variations of load inertia, robustness of the proposed ADRC system to inertia variation is analysed. Finally, to improve the tracking performance for sinusoidal speed-reference, an adaptive speed control system using identified inertia is presented. Simulation and experimental results verified the effectiveness of the proposed method.

A comparative study of new partitioned stator hybrid excitation axial flux switching permanent magnet (HEAFSPM) motors with different partitioned excitation stator topologies for in-wheel traction applications is presented in this paper. The realization approaches of the partitioned stator HEAFSPM motor are discussed, and the motor topology with windings and permanent magnets (PMs) separately setting on different stators is selected in view of the advantageous structure for thermal management. On this basis, two partitioned excitation stator topologies including C-type tooth core and T-type tooth core stator configuration are proposed, and the air-gap flux modulation and flux regulation principle of the motors are analyzed. In addition, the design method of the partitioned stator HEAFSPM motor considering the effect of hybrid excitation sources is provided, and the two motors with different tooth cores are designed respectively. Meanwhile, for a fair comparison, the multiple objectives optimization method coupled with the sensitivity analysis is employed to optimize the two motors. The electromagnetic performances, anti-demagnetization capability, and flux regulation performance of the two motors are all investigated in detail. Finally, two prototype motors are fabricated and tested. Both the theoretical analysis and experimental results verify the effectiveness and reasonability of the motor.

This paper investigates a novel 3-phase doubly salient permanent magnet (DSPM) motor. Because of the adoption of ⊓-shaped stator iron core segments, the asymmetrical magnetic circuit among different phases occurring in conventional DSPM motors with E-shaped stator iron core segments can be avoided, so that balanced and sinusoidal 3-phase PM flux linkage and no-load EMF can be achieved. Firstly, based on a 12/7 stator/rotor pole combination, the operation principle of ⊓-core DSPM motor is discussed using the least magnetic reluctance principle. Then the general airgap field modulation theory (AFMT) is extended to the ⊓-core DSPM motor for explaining its operation principle further and armature winding connection. The finite element analysis is used to validate theoretical analysis, as well as to calculate its electromagnetic performances. The results show that the 12/7-pole ⊓-core DSPM motor possesses higher average torque output capability and lower torque ripple compared with the 12/8-pole E-core counterpart. Finally, a 12/7-pole ⊓-core DSPM motor is built and tested so as to experimentally verify the theoretical analysis.

This article proposes a novel pole-changing (PC) permanent magnet (PM) Vernier machine (PC-PMVM), in which an unevenly distributed modulation tooth structure is adopted in the stator, and a set of three-phase PC-winding is installed in the stator slots. On the rotor, surface-mounted PMs are adopted to generate PM excitation field. First, the topology design principle of PC-PMVM is discussed for the purpose of PC, based on which a 12/34-pole PC-PMVM is proposed. The analytical analysis shows that there are a series of working harmonics in the air-gap and can be grouped into two different types with different phasor diagrams for realizing PC operation. Thus, the speed range can be widened greatly because of the different PM flux linkage and inductances before and after PC. Next, the electromagnetic performance of PC-PMVM is investigated by finite element analysis and compared with an interior PM motor and a PC induction motor. Finally, a prototype is manufactured and tested. The results verify the correctness of theoretical analysis, and show that the proposed motor owns both high torque density and excellent speed-widening capability benefiting from the PC design and PC operation.

In this paper, considering the oceanic multiple degree of freedom motion, a double stator linear-rotary permanent magnet (DSLRPM) generator with Halbach PM array is proposed for direct drive ocean energy conversion. It focuses on the power maximization generation resulting in a highly optimized DSLRPM generator to improve the generated power of the ocean energy conversion system in complex ocean condition. Based on the power-oriented design concept, the whole design process is divided into two steps. In the initial design procedure, the operating domain design is conducted, and the design point is selected. In the optimization design procedure, the non-dominated sorting genetic algorithm II (NSGA-II) coupled with response surface methodology (RSM) and sensitivity analysis is proposed to be as an optimization design technique. Finally, a prototype based on the optimized results is manufactured. The experimental results agree with the simulated result, and they both reveal that the proposed method can offer an effective design and optimization for the DSLRPM generator, where the multiple oceanic motions and complex operating conditions are considered.

This article proposes a multiple mode current (MMC) control for hybrid-excitation axial flux switching permanent magnet (HE-AFSPM) motors considering driving cycles. To satisfy the diverse and compound control demands in multiple operating condition of electric vehicles, the model predictive control is adopted, and multiple current vector prediction method including d -axis current, q -axis current, and dc excitation current is proposed to optimize current assignment ratio, enhance the dynamic performance, and improve motor efficiency. An online optimization method considering four operating conditions in two speed domains is demonstrated, where the different current assignment function and constraint is applied in each operating condition, and the optimal assignment currents are obtained effectively by the Lagrange multiplier method online in real time. Finally, to verify the feasibility of the multiple-mode control method, a prototype motor is built and tested. And, the motor performances in the different driving modes are investigated in detail. The experimental results reveal that the proposed control method can offer an effective control for the HE-AFSPM motor, where multimode operations are indispensable.