The suspension system with active magnetic bearing needs to solve the problem of rotor vibration caused by unbalanced interference. In this paper, the theoretical modeling and control methods are carried out for the multi-degree-of-freedom coupling effect and dynamic unbalanced vibration suppression problem of the active magnetic bearing-rigid rotating shaft system. Firstly, a four-degree-of-freedom dynamic model of a rigid rotor with unbalanced mass is established, and the dynamic decoupling of cross-coupling terms is realized by introducing the state feedback decoupling control strategy. Then, aiming at the dynamic unbalanced vibration caused by the unbalanced mass of the system, a current compensation algorithm based on parameter identification is studied to suppress the unbalanced vibration of the rotating shaft under the feedback decoupling framework. Both the simulation and experimental results verify the effectiveness of the decoupling of the system and the suppression of dynamic unbalanced vibration of the system.

The embedded magnetic encoder (EME) system calculates rotor position by detecting the permanent magnetic field (PMF) via linear Hall sensors installed inside the permanent magnet synchronous motors (PMSMs). However, during motor load operation, the coupling between the armature magnetic field (ARF) and the permanent magnetic field distorts the linear Hall sensor output signals, deteriorating the accuracy of rotor position estimation. To address this issue, this paper first analyzes the impact of armature reaction on linear Hall sensor signals and estimated rotor angle. Subsequently, an armature reaction compensation scheme is proposed to ensure robust position calculation accuracy. The effectiveness of the proposed method is experimentally validated.

Active disturbance rejection control using extended state observer (ESO) has been proved to be an effective method for voltage control of generator. However, the observation accuracy of conventional ESO is unsatisfactory. Thus, this paper proposes a robust voltage controller based on high-order ESO (HESO) for the permanent magnet synchronous generator (PMSG) to further suppress the time-varying disturbance. The disturbance rejection capability comparison between different order ESOs is carried out. It is shown that the proposed robust voltage controller based on high-order ESO has better anti-disturbance ability than the conventional ESO. The effectiveness of the proposed method is proved by the simulation results.

Speed inconsistency in multi-motor systems may lead to mechanical structure damage, low cooperative precision, and even cause equipment breakdown. Traditional control methods may induce pronounced consensus error fluctuations and prolonged convergence time under complex conditions such as system parameter mismatch, sudden load changes, and inaccurate mechanism models. To address these challenges, we propose a fixed-time cooperative model-free sliding mode control (FCM-SMC) method based on a fractional-order ultra-local model (FOULM). Specifically, the proposed approach integrates fractional-order dynamics into the system model to better capture the non-integer order characteristics of multi-motor systems. Then, to estimate the unknown terms of FOULM, a novel fixed-time disturbance observer (FTDO) is designed. Additionally, grounded in the framework of FOULM, the FCM-SMC protocol is designed to ensure that the consensus error of the multi-motor systems converges within a fixed time. Taking motor #1 as an example, compared with existing methods, the error metrics (ME, MAE, and RMSE) of the proposed method are reduced by up to 64.8%, 70.2%, and 69.7%, respectively.

This article aims to address the formation control issue of the unknown nonaffine nonlinear heterogeneous multiagent system (MAS) considering formation tracking accuracy and computational cost. A novel dynamic prescribed boundary-based event-triggered mechanism is proposed first to flexibly adjust the emphasis on these two indicators, and applied to data modeling and controller design simultaneously to reduce their computational cost. On one hand, an observer-based pseudo gradient estimation algorithm is designed under event-triggered framework for model reconfiguration with only input/output data of system rather than mathematical dynamics. On the other hand, an event-triggered constrained control strategy is developed with several modules to cope with complex scenarios. Concretely, a data-driven anti-windup compensator is designed in case of input constraint, and an improved prescribed performance-based fractional order terminal sliding mode controller is explored for enhancement of the formation tracking accuracy and robustness of the controlled MAS with rigorous stability analysis. Both numerical simulation and hard-in-the-loop experiment on distributed energy storage systems are performed to attest the efficacy of the proposed formation control strategy.

Multiple batteries in uninterruptible power supply (UPS)-microgrid systems based on multiagents composed of multiple electric vehicles (EVs) can encounter state of charge (SoC) consistency problems. To solve this differential expansion and controller saturation problem, an adaptive command filter sliding-mode control strategy based on virtual synchronous generators (VSGs) and considering the power allocation principle is proposed. First, based on directed graph theory, an SoC consistency algorithm and power allocation strategy for multiple EVs were proposed, forming a dc power system with a fixed communication topology. Second, the rotor motion equation of synchronous generator (SG) is introduced into the inverter control algorithm to form the mathematical model of VSG. Third, a low-pass filter (LFP) was introduced in the voltage control process to simulate the excitation attenuation characteristics of the SG. Based on the above, a backstepping control strategy, including a command filter and sliding mode controller is proposed, which improves the operating stability of the system based on the system errors of angle, frequency, and power output. Finally, the UPS-microgrid system based on multiagents is simulated to demonstrate the stability of the system and the effectiveness of the proposed control strategy.

To reduce the high torque ripple of a double-stator field-excitation (DSEE) machine, four torque ripple suppression techniques by optimizing the components shapes are proposed, namely, inner stator$(S_{I})$, rotor outer contour$(Ro)$, rotor inner contour$(R_{I})$, and outer stator (So). Further, the above techniques are evaluated from the perspectives of torque ripple and torque loss. Then, considering the manufacturing friendliness, cutting right angles on the outer side$(R_{0-\Pi})$and inner side$(R_{I-\Pi})$of the rotor techniques are proposed. The resultant torque characteristics indicate there is a significant difference in the torque ripple suppression capability of the six techniques when applying the shape optimization to different components of DSEE machine. Particularly, optimizing the rotor shape ($Ro$technique) has shown high effectiveness in torque ripple suppression, leading to an average torque ripple reduction of 67% while maintaining torque density by over 90%.

This paper proposes a non-symmetrical permanent-magnet linear motor traction system (PMLMTS), in which the primary permanent-magnet linear motor (PMLM) is employed. Four movers are mounted with same phase angles. There are nine legs, including eight independent legs and one common leg. All legs have same normal voltage but different normal currents. The normal current of the common leg is four times the normal current of the independent leg. Compared with axle-control topology, three legs are reduced in the non-symmetrical topology. As a result, the system complexity is simplified and the system reliability is enhanced. This paper also proposes the control method for the non-symmetrical PMLMTS. The effectiveness of the proposed topology and its control method are verified by simulation results.

This paper proposes a novel outer-rotor-permanent-magnet flux-switching (ORPMFS) machine for in-wheel light traction applications. Firstly, the geometric topology is introduced. Then the stator and rotor pole combination is discussed, and the stator slot area equation and permanent-magnet (PM) size equation are derived. Further, two 48-stator-slot ORPMFS machines with 22- and 26-rotor-pole are optimized. Then, based on 2D finite element analysis (2D-FEA), a comprehensive comparison between a pair of 48-stator-slot ORPMFS machines with 22- and 26-rotor-pole, and a 12-stator-slot 22-rotor-pole (12s/22p) outer-rotor stator-PM flux-switching (OR-SPM-FS) machine is performed. The results reveal that the 48s/26p ORPMFS machine has significantly better torque capability and higher efficiency than the 48s/22p ORPMFS counterpart and the 12s/22p OR-SPM-FS machine.

In this paper, a novel brushless machine with 12-stator-slot/8-rotor-pole having magnets surface-mounted in the stator instead of rotor is proposed, which can be regarded as an improved flux-reversal permanent magnet (FRPM) machine and is especially suitable for brushless DC operation. The topology, operation principle and static characteristics of the proposed three-phase 12/8 stator surface-mounted permanent magnet (SSPM) prototyped machine are analyzed based on 2-D finite element analysis. A comparison between the FRPM and SSPM machines having the same dimensions is presented including the field distributions, back-EMF, cogging torque and electromagnetic torque. In addition, an optimization on the key dimensions of the SSPM machine is explored to improve the characteristics of PM flux-linkage, back-EMF as well as to reduce cogging torque. The predicted results confirm that the SSPM machines with special stator slots and rotor poles combinations are attractive candidates in brushless DC drives.