Bearingless Permanent Magnet Synchronous Motor Research Articles

Design of Single-Winding Arrangement for Arbitrary Multiphase Bearingless Permanent Magnet Synchronous Motor

Design of Single-Winding Arrangement for Arbitrary Multiphase Bearingless Permanent Magnet Synchronous Motor

Torque System Modeling and Electromagnetic Coupling Characteristics Analysis of a Midpoint Injection Type Bearingless Permanent Synchronous Magnet Motor

Taking the Midpoint Injection type Bearingless Permanent Magnet Synchronous Motor (MPI-BL-PMSM) as an object, to solve its problems of large torque pulsation and insufficient suspension force when adopting Midpoint Suspension Current Unilateral Injection (MPSC-UI), a Midpoint Suspension Current Bilateral Injection (MPSC-BI) solution is proposed. Based on the half-winding structure of MPI-BL-PMSM, and from the electromechanical energy conversion principle, the torque model for MPSC-BI solution is established. On this basis, the torque model for MPSC-UI method was derived. The correctness of the established torque mathematical models based on half-winding structure was verified through the finite element method (FEM), and the “dual-frequency” electromagnetic coupling characteristics of suspension current on electromagnetic torque were compared and analyzed from the perspectives of theoretical model and FEM simulation. The results indicate that the MPSC-BI method can effectively suppress or avoid the torque pulsation coupled by suspension current and can obtain about 1-time increase of controllable suspension force; the advantages of MPSC-BI solution in dynamic torque decoupling characteristics are demonstrated, while the only downside is that the coupling effect of torque current on radial suspension force is slightly greater than that of the MPSC-UI method.

Design and harmonic analysis of single winding bearingless PM synchronous motor with high winding coefficient

Compared with double-winding bearingless permanent magnet synchronous motor, single-winding bearingless permanent magnet synchronous motor (SBPMSM) has the advantages of low copper loss and low failure rate. However, if the slot-pole combination of SBPMSM is not reasonably selected, the winding coefficient will be reduced, and even many advantages of the single-winding structure will be offset. In this paper, a single-winding design method based on magnetomotive force (MMF) star diagram is proposed, which can ensure high winding coefficient. The design process of the proposed single winding structure is introduced. This method can match the appropriate number of stator slots according to the number of rotor poles, and the winding phase separation design can be realized by reversing the slot number transposition. The mathematical models of the suspension force and torque of the bearingless permanent magnet synchronous motor are derived considering the magnetic field harmonics, and the 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are taken as examples to analyze the magnetic field. The finite element simulation models of 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are built and analyzed. Through the analysis of electromagnetic torque, suspension force and air-gap magnetic field under different magnetic fields, the general rules of main torque fluctuation and suspension force fluctuation are summarized.

Displacement Self-sensing Control of Outer Rotor Coreless Bearingless Permanent Magnet Synchronous Motor Based on Least Square Support Vector Machine Optimised by IMFO

Displacement Self-sensing Control of Outer Rotor Coreless Bearingless Permanent Magnet Synchronous Motor Based on Least Square Support Vector Machine Optimised by IMFO

Electromagnetic Performance Analysis of a Bearingless Permanent Magnet Synchronous Motor by Model Order Reduction

Electromagnetic Performance Analysis of a Bearingless Permanent Magnet Synchronous Motor by Model Order Reduction

Analysis of Multi-Harmonic Magnetic Field Coupling Characteristics of Bearingless Permanent Magnet Synchronous Motor

Analysis of Multi-Harmonic Magnetic Field Coupling Characteristics of Bearingless Permanent Magnet Synchronous Motor

Active Disturbance Rejection Control of Bearingless Permanent Magnet Synchronous Motor Based on Genetic Algorithm and Neural Network Parameters Dynamic Adjustment Method

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.

Decoupling Control of Outer Rotor Coreless Bearingless Permanent Magnet Synchronous Motor Based on Least Squares Support Vector Machine Generalized Inverse Optimized by Improved Genetic Algorithm

In the decoupling control process of the outer rotor coreless bearingless permanent magnet synchronous motor using a least squares support vector machine, the kernel width <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">σ</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the penalty factor <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">γ</i> of the least squares support vector machine are difficult to tune, resulting in high kernel space complexity and low fitting accuracy. A new improved genetic algorithm is used to optimize the above parameters. First, the generalized inverse system model of the original nonlinear multiple-input multiple-output system is fitted online with the optimized least squares support vector machine, and the generalized inverse system model is connected in series with the original system to form a pseudolinear system. Then, a linear closed-loop controller is used for control. Simulations and experiments show that the robustness and wide applicability of the original system are guaranteed. The dynamic and static performances of the system are improved, verifying the effectiveness of the scheme.

Multiobjective Optimization of a Five-Phase Bearingless Permanent Magnet Motor Considering Winding Area

Due to the increasing demand for high-speed motors with high stability, bearingless motors have attracted much attention. Bearingless permanent magnet synchronous motors (BPMSMs) are a kind of motor, which uses suspension force to eliminate the motor bearings. This article proposes a five-phase BPMSM with 10 slots and 8 poles. Based on the principle of suspension force of BPMSM, an analytical expression of the suspension force is derived for the proposed BPMSM. To improve the suspension stability and torque, an optimization method consisting of a response surface model and a multiobjective optimization algorithm is employed. Not only the geometric parameters but also the winding distribution are considered in the optimization process. Finally, the effectiveness and superiority of the optimal design are verified by experiment.

Study on the Effect of Suspension Windings on the Electromagnetic Vibration and Noise of Ultra‐high‐Speed Bearingless Permanent Magnet Synchronous Motor for Air Compressor

The electromagnetic vibration and noise level of ultra‐high‐speed bearingless permanent magnet synchronous motor (UBPMSM) for air compressors used in the fuel‐cell vehicle (FCV) is an important evaluation. A 10 kW, 100 k r/min UBPMSM is adopted as the object of study in this research. The expression of radial electromagnetic force of UBPMSM is derived through theoretical analysis, and the order and frequency characteristics of radial electromagnetic force harmonics are summarized. Through the two‐dimensional (2D) Fourier decomposition of radial electromagnetic force by finite element analysis (FEA), the main sources of radial electromagnetic force causing the electromagnetic vibration and noise are studied. The correctness of the mathematical model is verified by FEA. In addition, the three‐dimensional (3D) finite element model of the motor is established to calculate the radial modal, natural frequency, and electromagnetic vibration and noise of UBPMSM. The research shows that the spatial order of radial electromagnetic force of UBPMSM is kN and kN ± 1 (N = GCD [2p, Z], k = 1, 2, 3, …), and the noise change of UBPMSM caused by the addition of suspension windings could be ignored compared with ordinary motor. It provides reference values for the design and optimization of UBPMSM. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Vibration Compensation Control of BPMSM With Dead-Time Effect Based on Adaptive Neural Network Band-Pass Filter

In order to solve the problem of rotor vibration for the bearingless permanent magnet synchronous motor, a vibration compensation control method based on adaptive neural network band-pass filter (ANNBPF) is proposed. First, the mechanism of rotor vibration is obtained by theoretical analysis. Second, the ANNBPF is used to extract the components related to the frequency of the unbalanced vibration and the dead-time (DT) vibration to realize the vibration compensation control. Additionally, the DT effect is compensated by detecting the current polarity to improve the compensation effect. Finally, a vibration compensation control system based on ANNBPF and current polarity detection is constructed.

Optimization Design of Unequal Amplitude Modulated Poles for the Bearingless PMSM

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.

Multiobjective Optimization Design of Outer Rotor Coreless Bearingless Permanent Magnet Synchronous Motor

The outer rotor coreless bearingless permanent magnet synchronous motor (ORCBPMSM) is suitable for flywheel energy storage systems because of the advantages of no core loss and high efficiency. To improve the output torque and suspension forces of the motor, a Taguchi-response surface method (T-RSM) is proposed to conduct multiobjective optimization design of the motor. First, the basic structure and working principle of the proposed motor are expounded, and the basic design parameters of the motor are given. Then, the orthogonal matrix is established according to the number of factor levels, and the finite element analyze (FEA) is conducted to obtain each set of test results. After that, the sensitivity analysis is conducted and the best combination of variables can be achieved. Aiming at improving the accuracy of the Taguchi method, the fitting functions are established among the targets and conflicting variables, and the optimal solution is obtained by RSM. Finally, the optimal motor is manufactured, and the performance of the motor is verified. The experimental results show that stable operation can be obtained and the operating performance of the proposed motor is improved after optimization.

A novel consequent‐pole bearingless PMSM with integrated winding for flywheel energy storage

Generating torque and suspension force with one set of windings at the same time can increase the copper space factor and improve the torque output capacity. This structure has a unique application advantage for bearingless motors used in onboard flywheel energy storage. A consequent-pole bearingless permanent magnet synchronous motor (PMSM) with integrated winding is designed and researched. Regulating suspension current has minimal effect on the torque performance of the motor in this design. The effectiveness and feasibility of this design are verified through a finite element calculation. Its advantages and application scope are discussed.

Sensorless Control of Bearingless Permanent Magnet Synchronous Motor Based on LS-SVM Inverse System

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.

A new type of sinusoidal suspension winding Consequent-pole Bearingless Permanent Magnet Synchronous Motor

The existence of the harmonic of the suspension magnetomotive force is a key factor affecting the precision of the suspension force of the Consequent-pole Bearingless Permanent Magnet Synchronous Motor, and the coupling of motor’s suspension force in different degrees of freedom is obvious. Aiming at the improvement of the motor’s suspension performance, a 48 slot 8-pole consequent-pole bearingless permanent magnet synchronous motor with low harmonic suspension sinusoidal winding is designed in this paper. The effects of two kinds of sinusoidal suspension windings, 90° type and 120° type, on the optimization of suspension performance are analyzed, and the finite element analysis was used to verify that these two low-harmonic suspension winding structures, especially the 120° type, can effectively suppress the motor’s suspension magnetomotive force harmonics, improve the motor’s suspension force accuracy, and at the same time make the coupling problem between different suspension degrees of freedom of consequent-pole bearingless permanent magnet synchronous motor improved obviously.

Rotor radial displacement sensorless control of bearingless permanent magnet synchronous motor based on MRAS and suspension force compensation

Limitations exist on the displacement sensors employed in a bearingless permanent magnet synchronous motor (BPMSM). They lead to the increase in cost, size and complexity of the motor. Apart from that, the measurement errors are sensitive to the temperature and the electromagnetic noise. In order to resolve these problems, a novel rotor radial displacement sensorless control method of the BPMSM is proposed. In this paper, the operation principle and mathematical model of the BPMSM are introduced firstly. Secondly, the rotor radial displacement self-sensing method using the model reference adaptive system is designed. Thirdly, a direct control strategy of rotor eccentric displacement with suspension force compensation is proposed to promote the property of the displacement sensorless control system. Finally, a torque control subsystem based on the id=0 control scheme and a displacement control subsystem based on the proposed displacement self-sensing method and the suspension force control method are constructed. The related simulations and experiments are carried out. According to the research results, the rotor radial displacements of the BPMSM are effectively estimated and the stable suspension of the BPMSM rotor without displacement sensors is achieved.

Active disturbance rejection control of 5-degree-of-freedom bearingless permanent magnet synchronous motor based on fuzzy neural network inverse system

To realize the high performance operation of the 5-degree-of-freedom bearingless permanent magnet synchronous motor (5-DOF-BPMSM), a novel decoupling control strategy combining fuzzy neural network inverse system (FNNIS) with active disturbance rejection control (ADRC) is proposed. Firstly, fuzzy neural network (FNN) is employed to approach the inverse system of the 5-DOF-BPMSM. By connecting the obtained inverse system with the original system, six independent pseudo-linear subsystems are constructed. Then, considering the influence of parametric variations and external disturbances in the process of operation, the ADRC theory is employed to design additional closed-loop controllers to ensure the stability of the pseudo-linear subsystems. Finally, comparative simulation and experimental results indicate that the proposed control strategy can achieve better control performance.

Decoupling control of bearingless PMSM with LSSVM inverse system and IMC

In this paper, a novel decoupling control scheme combining least squares support vector machines (LSSVM) inverse models and 2-degree-of-freedom (DOF) internal model controllers (IMC) is employed in the decoupling control system of the bearingless permanent magnet synchronous motor (BPMSM). This scheme can be used to enhance the control properties of high-precision, fast-response, and strong-robustness for the BPMSM system, and effectively eliminate the nonlinear and coupling influence. It introduces LSSVM inverse models into the original BPMSM system to constitute a decoupled pseudo-linear system. In addition, the particle swarm optimization algorithm (PSO) is used to optimize parameters of the LSSVM, which improves its fitting ability and prediction accuracy. What is more, the internal model control scheme is used to design additional closed-loop controllers, thereby improving the robustness of the entire control system. Therefore, this scheme successfully combines the advantages of the LSSVM inverse models and the internal model controller. It can enhance the stability and the static as well as dynamic properties of the whole BPMSM system while independently adjusting the tracking and interference rejection performances. The effectiveness of the proposed scheme has been verified by simulation results at various operations.

Performance Benchmarking of a Novel Magnet-Free Bearingless Synchronous Reluctance Slice Motor

This paper presents a novel bearingless synchronous reluctance slice motor topology that contains no permanent magnets. The rotor with two iron poles and flux barriers is levitated and rotated through a stator winding system with six coils wired as two three-phase systems. A constant rotor-oriented magnetization current is applied to generate a magnetic bias flux. The system can be controlled similar to a bearingless permanent magnet synchronous slice motor and provides passive stabilization of axial and tilting movements of the rotor. The motor topology is discussed in detail and a prototype implementation is presented. Its performance with regard to passive properties, achievable torque, controllability, and wide air gap suitability is benchmarked against two other designs that contain permanent magnets either in the rotor or the stator. A loss analysis of all topologies is performed and suitable application areas are identified. The proposed design provides an interesting alternative to existing bearingless slice motor topologies in applications that require high rotational speeds, high process or ambient temperatures, or a disposable low-cost rotor with short exchange intervals.