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In order to improve the performance of motor drive systems, this paper introduces a sensorless control method for interior permanent magnet synchronous motors (IPMSM) based on the rotating high-frequency voltage injection method. The demodulation method using a synchronous frequency filter (SFF) instead of a bandpass filter (BPF) and a high pass filter (HPF) is proposed. The structure and transfer function of SFFs are introduced, and their characteristics are simulated and analyzed. Therefore, the center frequency of SFFs can be adaptively adjusted according to the estimated rotational speed, which is convenient for frequency setting. Finally, according to the proposed rotating high-frequency voltage injection method, the simulation model is built. The experimental results verify that the control strategy can maintain good position estimation accuracy, better speed tracking performance and anti-load disturbance performance. [ABSTRACT FROM AUTHOR]

The flux-concentrating permanent-magnet (FCPM) machine with two V-shape magnet pieces in one stator pole has attracted considerable attention due to its excellent torque density and permanent magnet (PM) usage efficiency, whereas the torque ripple of the FCPM machine is usually high. This article aims to make a multiobjective optimization design for the FCPM machine. The optimization process is divided into three steps for different optimization objectives on two sets of geometric variables at different operation conditions. The simulated results show that the output torque of the optimized FCPM machine is increased significantly while the torque ripple has been decreased greatly. Finally, the open-circuit field distributions, the output torque, the torque-speed characteristics, and PM demagnetization of the optimized FCPM machine are investigated considering different PM shapes and PM temperature rise, which indicates that the optimized FCPM machine has favorable torque characteristics, speed range, and antidemagnetization abilities. [ABSTRACT FROM AUTHOR]

In order to reduce the axial length and increase the critical speed of the small magnetic suspension drive system, a new slice hybrid magnetic bearing (SHMB) with two radial air-gaps is proposed. The structure and suspension mechanism of the SHMB is introduced, and then the mathematical models of the radial suspension force are deduced using the equivalent magnetic circuit method. The suspension mechanism is proved. The radial and axial suspension forces are then calculated by the finite element method. The experimental prototype SHMB is finally designed and constructed. The stable suspension of the rotor is realized, and the suspension forces are measured. The results of the finite element calculation and experimental measurement verify the correctness of the mathematical models. [ABSTRACT FROM AUTHOR]

The multimechanical-port double-rotor machine, as a core component in hybrid electric vehicles, has attracted considerable attention due to the merits of compact structure, control flexibility, and diverse performances. However, since there often exist two electric or mechanical ports in one compound machine frame, traditional design theory cannot be applied to it directly. Besides, because of the relatively complex machine structure and multiple design parameters, design objectives often influence even conflict with each other. In this paper, a new multiobjective optimization design approach is proposed to design and optimize a flux-modulated double-rotor flux-switching permanent magnet machine, where multiple driving modes are considered. To verify the feasibility of the double-rotor machine and the effectiveness of an optimization design method, the electromagnetic characteristics of the machine are investigated in detail. Finally, a prototype machine is built and tested. Both theoretical analysis and experimental results verify the validity of the proposed machine and multiobjective optimization design approach. [ABSTRACT FROM AUTHOR]

The flux-switching permanent-magnet (PM) double-rotor machine (FSPM-DRM) used for hybrid electric vehicles has attracted considerable attention due to the compact structure and high torque density. Compared with the conventional machine, the FSPM-DRM suffers from more iron loss, PM eddy-current loss, and conductor eddy-current loss for its larger rotor pole numbers. The iron loss exists not only in the stator but also in the rotor, while its calculation becomes more difficult due to complex flux density waveforms. A more accurate analytical model for the iron loss, PM eddy-current loss, and conductor eddy-current loss calculation is proposed for the FSPM-DRM and compared with the results from finite-element method. Based on the calculated losses, the efficiency of the FSPM-DRM is also investigated. Some experimental results are reported, validating the numerical and simulation results. [ABSTRACT FROM AUTHOR]

The flux-switching permanent-magnet double-rotor machine (FSPM-DRM) used for hybrid electric vehicles has attracted considerable attention due to the compact structure and high torque density. Compared with conventional machine, the FSPM-DRM suffers from more severe thermal problems in its inner rotor. This paper aims to make an accurate prediction of the performances and temperature distributions in the FSPM-DRM. First, the eddy current loss in windings with an improved analytical method is discussed and the results are validated by those from a 2-D finite-element (FE) model. With the obtained power losses, the lumped-parameter scheme considering end effect is compared with a 3-D FE thermal model to predict the temperature in each part of the FSPM-DRM at hybrid driving mode, in which both yield similar results. Then the maximum temperatures of different parts at the rated load and 160% load under various operational modes are simulated. Some experimental results are reported, validating the numerical and simulated results. [ABSTRACT FROM AUTHOR]

The traditional bearingless permanent magnet synchronous motor has complex decoupling control problems. To overcome the drawbacks above, a novel hybrid permanent magnet type bearingless motor (HPMTBM) is proposed in this paper, which has integrated the merits of hybrid excitation permanent magnet motor and magnetic bearings. The main advantages of this HPMTBM are the simple control mechanism and the low power consumption. First, the principle and theoretical background of this motor are introduced. Then, the mathematical models of radial suspension force and torque are established using Maxwell stress tensor method, and air-gap magnetic fields, radial suspension forces are calculated by finite-element analysis. Finally, the prototype motor is designed and constructed. The radial suspension forces and rotor radial displacements are tested. The simulation and experimental results show the feasibility of the proposed HPMTBM. [ABSTRACT FROM AUTHOR]

The use of double-rotor machines (DRMs) for hybrid electric vehicles (HEVs) has attracted considerable attention due to their compact structure and high torque density. Compared with the conventional four-quadrant transducer (4QT), the proposed flux switching permanent magnet double-rotor machine (FSPM-DRM) has PMs located in the stator, and can offer better performances in terms of magnetic coupling and torque ripple, which are especially important for DRM control in HEVs. This paper presents a comparative analysis of the 4QT and FSPM-DRM by employing the finite element method (FEM). For a fair comparison, two topologies are designed under the same peripheral dimensions, current density, and copper loss. Considering the effect of skewed slots in the 4QT, the corresponding performances are calculated with multi-slice 2-D time-stepping FEM. The simulated results illustrate that the proposed FSPM-DRM offers larger output torque, lower torque ripple, and smaller magnetic coupling than the 4QT. Nevertheless, the eddy current losses in PMs and windings of the FSPM-DRM are higher than those of the 4QT. Experimental results of the FSPM-DRM prototype are also given to verify the validity. [ABSTRACT FROM AUTHOR]

This paper proposes a new magnetic planetary geared permanent magnet brushless (MPG-PMBL) machine for hybrid electric vehicles. According to the dynamic performances in hybrid electric vehicles, the proposed machine needs to offer the advantages of high power density, high efficiency, and low torque ripple. To realize these goals, a multi-objective optimization design method based on the combined design of experiments approach and response surface method is presented, where three key optimization objectives of the efficiency, total loss, and cogging torque are selected. After the optimization, some reasonable key design variables are determined and the proposed MPG-PMBL machine is newly designed and built for evaluation. Both theoretical analysis and experimental results verify the validity of the proposed optimization method. [ABSTRACT FROM AUTHOR]

This paper proposes an axial permanent magnet-biased hybrid magnetic bearing, which possesses the advantages of low power consumption, simple structure, and easy control. The structure and operation principle are introduced. Then, the mathematical models, including the suspension force expression, are built based on traditional equivalent magnetic circuit. In addition, the basic principle of structure parameter design is presented, based on which the key parameters are given. Due to the inaccuracy of the traditional equivalent magnetic circuit, an improved method for magnetic circuit is introduced. Last, the accuracy of the analytical method is validated by finite element analysis and it also has an important reference value for other types of magnetic bearings design. [ABSTRACT FROM AUTHOR]