Search Results (9)

Bearingless interior permanent magnet synchronous motors (BIPMSMs) have received considerable attention in recent research due to their advantages of high speed, high power density, and absence of mechanical wear. In order to improve the torque and suspension performance of the BIPMSM, an optimization design method of BIPMSM is proposed in this paper based on sensitivity analysis, response surface fitting, and the multi-objective whale optimization algorithm (MOWOA). Firstly, the structure and operation principle of the BIPMSM are introduced. Secondly, significant variables are extracted based on sensitivity analysis. Then, regression equations of the significant variables and optimization objectives are fitted by the response surface method, and global optimization is performed with MOWOA. Finally, the motor performance before and after optimization is compared. The results demonstrate that the proposed multi-objective optimization design scheme can significantly improve the performance of the BIPMSM and effectively shorten the design cycle. Full article

High production costs and extended development timelines pose significant challenges to the manufacturing of bearingless permanent magnet synchronous motors (BPMSMs). Moreover, uncertainties regarding the motor’s ability to generate suspension and torque often persist even after prototyping, primarily due to the limitations of lumped parameter models in capturing the system’s complex dynamics. Since this technology is not yet fully consolidated, there is a clear need for a solution that enables the effective evaluation of BPMSMs prior to physical production. To address this, a reduced-order model (ROM) was developed for BPMSMs with combined windings, capturing the cross-coupling effects associated with rotor eccentricity, magnetic saturation, and topological complexity. The model was constructed using the parametric interpolation method (PIM), enabling efficient and accurate representations of nonlinear electromechanical behavior as ferromagnetic materials and spatial harmonics are addressed through finite element modeling. Additionally, hardware-in-the-loop (HIL) techniques were used for gain tuning, and active disturbance rejection control (ADRC) was applied to enhance performance. This combined approach offers a comprehensive solution for the design and control of BPMSMs. Full article

This work focuses on small bearingless permanent magnet synchronous motors (BPMSMs). In order to enhance its torque control stiffness and improve the stability of its torque and magnetic levitation force dynamic waveforms, a novel six-phase distributed single-winding BPMSM with 12 slots and 2 poles (six-phase DSW-12/2-BPMSM) is proposed and researched in this work. First, the structure and working principle of the six-phase DSW-12/2-BPMSM are analyzed. Subsequently, considering the relative permeability of permanent magnets, mathematical models of the inductance matrix, electromagnetic torque and radial magnetic levitation force are established. Then, using the finite element method (FEM), the control characteristics of the electromagnetic torque and magnetic levitation force of the six-phase DSW-12/2-BPMSM are analyzed, and the mathematical model is verified. Finally, FEM simulation analysis and comparisons are conducted with a commonly used six-phase centralized single-winding BPMSM with 6 slots and 2 poles (six-phase CSW-6/2-BPMSM). The research results show that the established mathematical model is effective and accurate compared with the six-phase CSW-6/2-BPMSM. The six-phase DSW-12/2-BPMSM has greater torque control stiffness, its dynamic waveforms of torque and radial magnetic levitation force have higher quality and stability, and the coupling degree between its torque and radial magnetic levitation force is lower. Full article

In order to solve the problem of poor control performance, caused by fixed parameters of the active disturbance rejection control (ADRC) in bearingless permanent magnet synchronous motors (BPMSM), a dynamic parameters adjustment method of ADRC, based on a genetic algorithm and back-propagation neural network (GA-BPNN), is proposed. Firstly, the ADRC control models of motor-side and suspension-side are established, according to the motor speed formula and suspension force formula. Secondly, the BPNN algorithm is used to dynamically adjust the parameters of the ADRC, and the operation processes of BPNN are deduced, according to the chain rule. Thirdly, in order to avoid the problem of getting out of control, caused by the convergence failure of BPNN, a GA based on floating point coding is used to optimize the initial value of BPNN. Finally, these methods are integrated to form a BPMSM control system, based on the GA-BPNN-ADRC, and the effectiveness is verified on an experimental platform. The experimental results, show that the proposed method reduces the failure probability of the system from 35.61% to 0%, and the anti-interference ability and dynamic performance of the speed and displacement of the control system are significantly improved. Full article

The structural parameters of an equal amplitude modulated magnetic pole is limited by the length of the air-gap. When the modulation ratio or carrier ratio is small, the spacing of permanent magnets is too large, which will lead to a worse cogging effect, and then the torque optimization effect is not satisfying. In order to improve the operation stability of a bearingless permanent magnet synchronous motor (bearingless PMSM), an unequal amplitude modulated magnetic pole structure is proposed according to the principle of magnetic pole modulation. The Taguchi method is used to optimize the structural parameters of the unequal amplitude modulated magnetic pole with the goal of reducing the torque and suspension force fluctuation. Three kinds of magnetic pole structures, named the whole magnetic pole, the equal amplitude modulated magnetic pole and the unequal amplitude modulated magnetic pole are compared and verified. The results show that the proposed structure of the unequal amplitude modulated magnetic pole can effectively further decrease the torque and suspension force fluctuations under the premise of the output capacity of the motor being unchanged, which improves the performance of the bearingless PMSM. Full article

The traditional bearingless synchronous reluctance motor (BSynRM) with salient pole rotor has some drawbacks such as high suspension force ripple, low torque density and low power factor. To overcome the above shortcomings, the permanent-magnet-assisted bearingless synchronous reluctance motor (PMa-BSynRM) is proposed. In this paper, two types of PMa-BSynRM rotors with the same number of permanent magnets but different magnetic barrier structures are designed. A traditional BSynRM with a salient pole rotor is introduced, and the electromagnetic and vibration characteristics of the three BSynRM are analyzed and compared. Firstly, the rotor structures of the two PMa-BSynRMs are designed, and the operation principle of the BSynRM is introduced. Secondly, electromagnetic characteristics of the three motors are analyzed and compared in detail using FEA software. Thirdly, the vibration analysis of the three motors is carried out. Finally, the experimental prototype platforms are built. The FEA and experimental results verify that the designed PMa-BSynRM can improve the power factor and torque density of traditional BSynRMs, and the most superior BSynRM among the three is identified. Full article

In order to solve the problems of low integration, low reliability, and high cost caused by mechanical sensors used in bearingless permanent magnet synchronous motor (BPMSM) control systems, a novel speed and displacement sensorless control method using a least-squares support vector machine (LS-SVM) left inverse system is proposed in this paper. Firstly, the suspension force generation principle of the BPMSM is introduced, and the mathematical model of the BPMSM is derived. Secondly, the observation principle of the left inverse system is explained, and the left reversibility of the established speed and displacement subsystem is proved. Thirdly, the left inverse systems of the speed and displacement subsystems are constructed by using the LS-SVM, and the complete speed and displacement sensorless control system is constructed. Finally, the simulations and experiments of the proposed method are performed. The research results demonstrate that the proposed observation method can identify the speed and displacement quickly and accurately, and the sensorless control method can realize the stable operation of the BPMSM without speed and displacement sensors. Full article

At present, because of their advantages of simple structure, low cost, low power consumption and high efficiency, single winding bearingless permanent magnet synchronous motors (SBPMSMs) have become one of the research hotspots in the bearingless technology field. However, a high motional-electromotive force (EMF) is generated by rotor rotation in the single winding, which already has side-effects on the normal suspension force current, and the suspension force response can be delayed. Because the method of double torque current inverse injection in the symmetrical winding allows the motional-EMFs of the corresponding phase windings to offset each other in the opposite direction, with no adverse effects on original performance, a T-shaped single winding configuration is proposed to realize precisely that effect. In this paper, the analytical expressions of the radial suspension force and torque are deduced and the motional-EMF and performance are analyzed by finite element method using the Ansys-Maxwell software. In addition, a suspension force vector closed loop control strategy is proposed to improve the suspension performance. The complete control strategy of torque and suspension force is designed based on the above motor winding configuration. Finite element analysis (FEA) is used to verify the T-shaped winding structure. The control strategy is demonstrated by software (MATLAB) simulation and an experimental prototype. These results show that the winding structure and the control strategy can achieve the desired effect, improving the radial suspension force. Full article

Bearingless permanent magnet synchronous motors (BPMSMs), with all advantages of permanent magnet motors (PMSMs) and magnetic bearings, have become an important research direction in the bearingless motor field. To realize a stable suspension for the BPMSM, accurate decoupling control between the electromagnetic torque and radial suspension force is indispensable. In this paper, a concise and reliable analysis method based on a magnetic field equivalent current is presented. By this analysis method, the operation principle is analyzed theoretically, and the necessary conditions to produce a stable radial suspension force are confirmed. In addition, mathematical models of the torque and radial suspension force are established which is verified by the finite element analysis (FEA) software ANSYS. Finally, an experimental prototype of a 2-4 poles surface-mounted BPMSM is tested with the customized control strategy. The simulation and experimental results have shown that the motor has good rotation and suspension performance, and validated the accuracy of the proposed analysis method and the feasibility of the control strategy. Full article