In the permanent magnet synchronous motor speed regulation system, the dynamic performance of the conventional active disturbance rejection control (ADRC) system will be deteriorated by using a low bandwidth speed filter. To solve this problem, two ADRC controllers considering the speed measurement noise are proposed in this article. One proposed ADRC system is based on the extended state observer (ESO), the other proposed ADRC system is based on phase-locking loop observer (PLLO). In the proposed two ADRC systems, an integrator is employed as the speed filter so that the measured position can be directly used for observing the speed and disturbance without speed calculation. Meanwhile, by using an integrator as the speed filter, the dynamic performance of the proposed ESO-based ADRC system is not affected since it is independent of the speed filter, and the proposed PLLO-based ADRC system has a better rejection ability for the low-frequency disturbance. Experimental results validate the proposed methods.

To suppress the torque ripple for smooth speed control of electric drives, active disturbance rejection (ADR) controller based on generalized integrator (GI) extended state observer (ESO) (GIESO) is developed in this article. Deadbeat ADR controller is employed to control the current, allowing the current control algorithm to be simplified. An adaptive GIESO is developed to address the instability problem caused by the two-step delay in the current control loop. Based on the system stability analysis, the design guideline for the adaptive resonant gain is determined. The proposed adaptive GIESO allows the system to be stable across the entire speed range while suppressing speed ripple to within 1 r/min.

In this paper, a comparative study of permanent-magnet vernier (PMV) motors and the interior permanent-magnet (IPM) motor for hybrid electric vehicles (HEVs) is presented. Four different topologies of PMV motors, including the conventional PMV motors and the developed U-shape PMV (U-PMV) motors with full-pitch (FP) and short-pitch (SP) windings, are comprehensively investigated and compared. The results show that higher torque and PM utilization can be achieved in the developed U-PMV motors due to the improved flux modulation effect. In addition, SP windings can facilitate PMV motors to achieve higher output torque/power, efficiency, and PM utilization when a high power factor is required. The improvement of the flux modulation effect in the developed U-PMV motors is explained using the simplified magnetic circuit, while the advantages of SP winding over FP winding at a high power factor level are illustrated using winding function theory. To evaluate the performances and potential of PMV motors for HEVs, both the conventional PMV and the developed U-PMV motors are optimized and compared with the IPM motor under fair conditions. The results show that PMV motors offer higher torque density, power density, and lower torque ripples, compared to the IPM motor. However, more PM consumption and higher cost of PMV motors are the disadvantages of PMV motors for automotive applications where cost constraints are sensitive.

Deadbeat predictive current control (DPCC) with a linear disturbance observer (LDO) in the surface-mounted permanent magnet synchronous machine (SPMSM) has been widely applied in many applications due to better dynamic response performance and easy implementation. However, the evaluated lumped disturbances caused by current measurement noises, inverter nonlinearity, abrupt reference current, and initial inductance parameter mismatch can restrain the high-performance development. In order to handle this issue, an enhanced DPCC with LDO is proposed in this article, where a modified DPCC with the LDO model and the noninvasive inductance and inverter disturbance observer are developed. In this case, the initial inductance parameter mismatch and high-frequency disturbances effect on the DPCC with LDO is reduced, while the current measurement noises’ suppression is enhanced by the proposed LDO. The theoretical analysis has shown that the proposed DPCC with LDO has a better performance than the conventional DPCC with LDO. Also, the superiority of the proposed DPCC with LDO has been validated by an SPMSM drive test rig.

This article investigates the stator shifting technique (SST) for permanent magnet Vernier (PMV) machines equipped with two-slot pitch winding (TSPW). By employing SST, TSPWs can be generated from the combination of two sets of fractional-slot concentrated windings, with various shift angles. The effects of various shift angles on armature magnetomotive force harmonic contents are explored. It shows that proper shift angles can be selected to preserve the working component while eliminating loss-producing harmonics. Besides, the implementation of various shift angles leads to uneven stator teeth structure, which affects field modulation. Therefore, the output torque capability, phase inductance, power factor, core losses, and fault-tolerance are affected by different shift angles. This article aims to exploit the full potential of TSPW-PMV machines by SST, considering the synthetic effects on harmonic reduction and field modulation. Through the exemplification of 24- slot, 19-rotor pole pair, and 5-armature pole pair PMV machines, it indicates SST is a more general and flexible design method that can provide new design opportunities and improve various performance metrics by introducing shift angle as an additional design variable. Finally, a prototype of the double-layer TSPW-PMV machine with optimal shift angle is fabricated for concept validations.

This article investigates a high power-factor permanent magnet vernier machine (PMVM) equipped with low-coupling hybrid concentrated-winding (CW). The proposed hybrid-CW, carrying both star- and delta-winding sets, exhibits a good filtering property to both sub- and super-order harmonics. Through the meticulous design of the short coil pitch, the ratio of inductance to magnet flux linkage is decreased, leading to a great improvement in power factor. The proposed low-coupling winding design contributes to further power factor improvement by reducing the inductance while retaining the magnet flux linkage. It is revealed that the mutual coupling between different coils of a single phase and that between different windings of three phases is suppressed significantly in the hybrid-CW, thus leading to a high power factor and potentially high fault tolerance. Finite element results show that the proposed hybrid-CW PMVM exhibits a significantly improved power factor up to 0.96 from 0.83 and 0.75, as compared with two counterpart PMVMs with open-slot and split-tooth structures, respectively. Benefiting from the magnetic gearing effect, the proposed PMVM has a promising active torque density of 40 N⋅m/L. Taking the end-winding volume into consideration, the proposed PMVM exhibits an actual torque density of 21.98 N⋅m/L, which is 22.52% and 52.43% higher than the investigated open-slot and split-tooth counterpart PMVMs. Finally, a prototype is fabricated and tested to validate the high-power-factor and high-torque-density features of the proposed hybrid-CW PMVM.