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This paper proposes an E-core outer-rotor hybrid-excitation flux switching (OR-HEFS) machine for in-wheel direct driving application. According to the general air gap field modulation theory, the magneto-motive force (MMF) permeance model was established to investigate the air gap flux density, and then the torque generation, the flux regulation principle, and the excitation-winding-induced voltage of the E-core OR-HEFS machine were analyzed. To characterize the output performances, the influence of the design parameters was investigated for the E-core OR-HEFS machine, including the split ratio, stator tooth arc, PM arc, fault-tolerant tooth arc, rotor tooth arc, stator yoke width and rotor yoke width. The performances contained the output torque, torque ripple, flux regulation ratio, and the excitation-winding-induced voltage. On this basis, the aforementioned four performances were optimized by means of the non-dominated sorting genetic algorithm II (NSGA-II). Based on the optimization result, a prototype was manufactured and tested to verify the whole investigation of this paper. [ABSTRACT FROM AUTHOR]

An axial field hybrid excitation synchronous generator (AF-HESG) is proposed for an independent power supply system, and its electromagnetic performance is studied in this paper. The distinguishing feature of the proposed generator is the addition of static magnetic bridges at both ends to place the field windings and the use of a sloping surface to increase the additional air-gap cross-sectional area. The advantage of the structure is that it achieves brushless excitation and improves the flux-regulation range. The structure and magnetic circuit characteristics are introduced in detail. Theoretical analysis of the flux-regulation principle is conducted by studying the relationship between field magnetomotive force, rotor reluctance, and air-gap flux density. Quantitative calculation is performed using a magnetomotive force (MMF)-specific permeance model, and the influence of the main parameters on the air-gap flux density and flux-regulation range is analyzed. Subsequently, magnetic field, no-load, and load characteristics are investigated through three-dimensional finite element analysis. The loss distribution is analyzed, and the temperature of the generator under rated conditions is simulated. Finally, a 30 kW, 1500 r/min prototype is developed and tested. The test results show good flux-regulation capability and stable voltage output performance of the proposed generator. [ABSTRACT FROM AUTHOR]

Hybrid-excited generators have a wide voltage regulation capability or a wide range of variable-speed constant-voltage output capability, providing a significant advantage in the new energy power generation field. To achieve the optimal design of brushless hybrid excitation synchronous generators with third harmonic excitation, it is necessary to grasp the influence of design parameters on excitation power accurately. Firstly, this paper elaborates on the structure and principle of the hybrid excitation synchronous generator. From the perspective of excitation power generation, the expression for excitation power in hybrid excitation generators has been derived, identifying the primary factors influencing excitation power, which include winding parameters, structural parameters, and magnetic circuit saturation. Secondly, qualitatively calculate the influence of the number of turns and arrangement, turns in rotor harmonic, air gap length, and thickness of the permanent magnet on the excitation power, which is verified by the electromagnetic field finite element method. The results showed that the use of full pitch and a moderate increase in turns, a decrease in air gap length, and an increase in the thickness of the permanent magnet can all increase the rotor excitation power. A brushless hybrid excitation synchronous generator prototype based on third harmonic excitation was developed, the correctness of theoretical analysis and calculation were verified by test results. [ABSTRACT FROM AUTHOR]

Similar to armature back electromotive force (armature back-EMF), the back-EMF also exists in the field winding of hybrid excited machines. However, the existence of field back electromotive force (field back-EMF) is harmful to the safe and stable operation of machine systems, e.g., higher losses, lower efficiency, higher torque ripple, and reduced control performance. This paper systematically investigates the influence of armature/field winding configurations together with stator/rotor pole combinations on the field back-EMF ripple in hybrid excited machines with switched-flux stators. The two-dimensional (2D) time-stepping finite element modeling and prototyping experiments are used for the research. The investigated field and armature coil pitches equal to 1, i.e., non-overlapped windings. The influential factors that are investigated in this paper mainly include the number of layers of field/armature windings, the number of field/armature coils, and the stator/rotor pole combinations. The results show that the field back-EMF's harmonic order and peak-to-peak value are closely associated with field/armature winding configurations and stator/rotor pole combinations under various conditions. Finally, for validation of the results predicted by the finite element method, a prototype machine is built and tested. Overall, non-overlapped double-layer armature and field windings are recommended for the hybrid excited switched flux machines with various stator/rotor pole combinations to realize relatively lower field back-EMF under different conditions. [ABSTRACT FROM AUTHOR]

The hybrid excitation eddy current damper is a novel principle damper characterized by high reliability, simple structure, and controllable magnetic field. Under intensive impact loads, hybrid excitation electromagnetic damping can induce demagnetization effects, resulting in significant fluctuations of the electromagnetic damping force at 6-8 ms. To mitigate this phenomenon, this study established a finite element model of the hybrid excitation damper using COMSOL and developed a control module based on a BP neural network in Simulink. Through co-simulation of COMSOL and Simulink, the difference between the maximum and minimum electromagnetic damping force at 6-8ms is reduced from 45 kN to 5 kN. This research provides valuable technical references for the optimization and practical application of eddy current dampers. [ABSTRACT FROM AUTHOR]

According to the different excitation methods, automotive eddy current retarders (ECRs) can be divided into electrically excited retarders (EERs) and permanent magnet excited retarders (PMERs), and EERs and PMERs have certain complementarity in control and braking characteristics. Therefore, based on literature research, this article proposes a hybrid excitation rotary electromagnetic retarder (HERER) and conducts numerical simulation analysis and experimental research on the braking performance of the HERER. Firstly, the structure and working principle of the HERER are introduced. Secondly, based on the principles of electromagnetics, an equivalent magnetic circuit analysis model of the HERER is established. Then, a finite element analysis model of the HERER is established using Jmag 14 electromagnetic simulation software, and the braking performance of the HERER under different current and speed conditions is studied. Finally, bench tests are conducted on the air loss torque and eddy current braking performance of the HERER. The effectiveness of the finite element analysis model and equivalent magnetic circuit model of the HERER is verified. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract This research paper introduces the Double Stator (DS) Hybrid Excitation (HE) Halbach Permanent Magnet (HPM) Flux Switching (FS) machine. The machine construction and its optimization specifically designed for electric vehicle (EV)/hybrid electric vehicle (HEV) traction applications are investigated. The optimization using a multi-objective Genetic Algorithm is conducted following a sensitivity analysis-based identification of key optimization parameters and constraints. The finite element results are compared with the performance of a state-of-the-art benchmark FSPM machine having identical PM volume and winding current densities. The proposed design is shown to outperform the benchmark with 16.2% increase in back-electromotive force and 14.7% reduction in cogging torque. Furthermore, the average torque is improved at flux-enhancing operation by 20.8%, and the torque ripple is reduced by 9.9%. Notably, the proposed machine also is capable of flux regulation thereby having the ability to operate in a wide speed range. A detailed explanation of the reasons for the significant improvements in the proposed machine structure is provided to offer a comprehensive understanding of its rationale. These research findings indicate that this innovative DS-HE-HPM-FS machine can enhance the performance of EVs and HEVs.

This research paper introduces the Double Stator (DS) Hybrid Excitation (HE) Halbach Permanent Magnet (HPM) Flux Switching (FS) machine. The machine construction and its optimization specifically designed for electric vehicle (EV)/hybrid electric vehicle (HEV) traction applications are investigated. The optimization using a multi-objective Genetic Algorithm is conducted following a sensitivity analysis-based identification of key optimization parameters and constraints. The finite element results are compared with the performance of a state-of-the-art benchmark FSPM machine having identical PM volume and winding current densities. The proposed design is shown to outperform the benchmark with 16.2% increase in back-electromotive force and 14.7% reduction in cogging torque. Furthermore, the average torque is improved at flux-enhancing operation by 20.8%, and the torque ripple is reduced by 9.9%. Notably, the proposed machine also is capable of flux regulation thereby having the ability to operate in a wide speed range. A detailed explanation of the reasons for the significant improvements in the proposed machine structure is provided to offer a comprehensive understanding of its rationale. These research findings indicate that this innovative DS-HE-HPM-FS machine can enhance the performance of EVs and HEVs. [ABSTRACT FROM AUTHOR]

This paper conducts the structural design and a fuzzy PID control for the hybrid excitation eddy current recoil absorber (HE-ECRA) aimed at mitigating the impact of instantaneous intensive load on the artillery mount. Firstly, a structurally simpler HE-ECRA is designed to replace the traditional hydraulic recoil absorber. It not only circumvents issues such as liquid leakage and maintenance difficulties associated with the traditional hydraulic structure but also enables real-time control of resistance. Subsequently, equivalent subdomain (analytical) and finite element models are established for the HE-ECRA. By inputting the artillery launch load, the operational performance, as well as the relationship between structural parameters and the resistance law, are investigated. Finally, a stable resistance control method for the HE-ECRA based on a fuzzy PID strategy is proposed. A co-simulation platform was developed to facilitate bidirectional dynamic data transmission between the recoil motion parameters and excitation current. The research indicates that the controlled HE-ECRA can mitigate the ’saddle’ effect, enhance the stability of recoil resistance, and reduce the impact effect of launch load on the artillery mount. This paper provides a universal buffering solution for structures subjected to transient high-impact loads and offers a feasible method for real-time resistance control. [ABSTRACT FROM AUTHOR]

As one sort of flux modulation machine based on magnetic gear effect, field-modulated machine features with low speed large torque. A novel hybrid excitation field-modulated machine (HEFMM) is proposed by introducing the concept of hybrid excitation, the flux modulation poles (FMPs) and excitation winding of which are emplaced in stator teeth and the adjacent FMPs. It can be maintained wide speed range operation through the processes of flux-enhancing and flux-weakening with no increasing machine bulk, as well as the numbers of stator and rotor slot. The working principle of proposed machine is deeply studied, as well as basic electromagnetic characteristics are calculated by finite element method, including no-load magnetic flux linkage, no-load back electromotive force, cogging torque and output torque. In addition, the processes of flux-enhancing and flux-weakening are analyzed. Finally, one prototype with one kilowatt was built and its static characteristics were tested. The results show that the proposed HEFMM has the features of high torque density, small cogging torque and wide speed range, which is promising candidate for electric vehicle direct drive field. [ABSTRACT FROM AUTHOR]

The Hybrid Excitation Flux Switching Permanent Magnet (HEFSPM) motor with magnetic bridge is a topology of hybrid excitation Flux-Switching Permanent Magnet (FSPM) machines. Despite its excellent performance such as high torque/power density, high flux enhancing/weakening capability and so on, it has received less attention due to its complicated structure. Therefore, its optimal design and performance all need to be further investigated. This paper presents a multi objective optimization design of a HEFSPM motor with magnetic bridge based on design sensitivity analysis. At first, the machine structure and basic working principle are discussed briefly. Then, a design sensitivity analysis for geometric optimization is carried out to improve the motor performance. This optimized motor is compared with initial design. Finally, a prototype of the optimized proposed motor is built and tested to validate the simulation results. [ABSTRACT FROM AUTHOR]

This paper discusses the construction and operating principle of an axial flux electric machine with hybrid excitation. Based on computer simulations using the Finite Element Method, an analysis was conducted with changes in the geometry of the magnetic circuit, which involves the rotation of the rotor disks relative to each other on the operating parameters of the machine. Both the generator state of operation, in the meaning of analyzing the induced voltage (adjustment at −11% ÷ +64%) and the cogging torque, and the motor state of operation, in the meaning of analyzing the ripple of the electromagnetic torque (possible reduction by almost 30%), were examined. The article concludes with observations on how the change in the angle of the rotor disks affects the efficiency of the disk machine with axial flux and hybrid excitation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The magnetic potential source of a tangential magnetizing parallel structure hybrid excitation synchronous motor (TMPS-HESM) is generated by both the permanent magnets and the excitation winding. Objectives: As the positive excitation current flows in, the radial electromagnetic force wave amplitude of the motor increases sharply, resulting in an over-limited electromagnetic vibration noise. Methods: To address this issue, a 2.5 kW TMPS-HESM is used as the object of study. First, an analytical model of the radial electromagnetic force wave of a hybrid excitation motor is developed using the Maxwell stress tensor method under the operating conditions considering armature reaction and the influence of the length of the pole piece on the air gap side and the pole eccentricity distance on the radial electromagnetic force wave was analyzed. Then, using the above variables as optimization variables, the joint simulation method of Maxwell & Workbench & optiSLang based on PSO was used to optimize the design with the mean and maximum values of average motor torque, torque pulsation, and A-weighted noise as the objectives, and the optimal structural dimension parameters were selected through the Pareto front surface. A multi-physics finite element model was established to compare the spatiotemporal distribution characteristics of radial electromagnetic force and vibration and noise spectra before and after optimization. Finally, a hybrid excitation motor vibration experiment platform was built, and the vibration acceleration on the surface of the motor casing was tested and analyzed under load and no-load conditions. Results: The results show that the adopted multi-objective optimization results can effectively weaken the electromagnetic vibration and noise of the hybrid excitation motor, and provide a reference for the design of vibration and noise reduction of related complex structure motors. [ABSTRACT FROM AUTHOR]

To further enhance the speed regulation range of the hybrid excited machine (HEM), the structure of a magnetic ring is optimized using a combination of the magnetic circuit method (MCM) and numerical analysis method in this paper, and a disc magnetic ring (DMR) is proposed. The magnetic density distribution of the proposed disc magnetic ring hybrid excited machine (DMRHEM) is compared to the radial-axial hybrid excited machine (RAHEM), and the superiority of alleviating a saturation problem in the proposed DMRHEM is determined. To improve the power density, the spoke-type permanent magnet (PM) rotor is applied. The influence of the proposed DMR on the HEM is analyzed, and the field adjustment capability of the proposed DMRHEM is better. Based on this, by combining the bypass principle, the analytical expressions for the relations between the rotor pole-pair number and the motor axial length/stator inner diameter (MAL/SID) as well as flux regulation capability are derived to further explore the superiority of the proposed DMRHEM. The influence mechanism of the rotor pole-pair number and the MAL/SID on the proposed DRMHEM is determined. The optimal MAL/SID and pole-pair number are obtained. [ABSTRACT FROM AUTHOR]

According to the different excitation methods, automotive eddy current retarders (ECRs) can be divided into electrically excited retarders (EERs) and permanent magnet excited retarders (PMERs), and EERs and PMERs have certain complementarity in control and braking characteristics. Therefore, based on literature research, this article proposes a hybrid excitation rotary electromagnetic retarder (HERER) and conducts numerical simulation analysis and experimental research on the braking performance of the HERER. Firstly, the structure and working principle of the HERER are introduced. Secondly, based on the principles of electromagnetics, an equivalent magnetic circuit analysis model of the HERER is established. Then, a finite element analysis model of the HERER is established using Jmag 14 electromagnetic simulation software, and the braking performance of the HERER under different current and speed conditions is studied. Finally, bench tests are conducted on the air loss torque and eddy current braking performance of the HERER. The effectiveness of the finite element analysis model and equivalent magnetic circuit model of the HERER is verified.

Aiming at the engineering limitations of traditional ship vibration online monitoring and noise prediction methods, this paper proposes a method for online monitoring and underwater radiation noise prediction of cabin structures' vibration and noise under hybrid excitation of sound and force. The method first constructs the condition test model; based on OTPA technology, the "acoustic-vibration" transfer function between sound and vibration monitoring points in the cabin and the "acoustic/vibration-acoustic" transmission network inside and outside the cabin structure are obtained. Secondly, based on the "acoustic-vibration" transfer function, the online vibration and sound monitoring data are decoupled and processed to obtain the modified vibration and sound monitoring data. Finally, the near-field radiation noise on the conformal hologram surface outside the cabin is predicted based on the "acoustic/vibration-acoustic" transmission network, and the far-field radiation noise of the cabin structure is predicted by the wave superposition method. In this paper, the contribution law of external radiation noise and the coupling characteristics of the monitoring information under the hybrid excitation of sound and force are analyzed theoretically, and the decoupling method of coupling information is also studied. This method makes up for the problem of missing underwater radiation noise caused by sound excitation in traditional vibration monitoring, and it can effectively improve the prediction accuracy of underwater radiation noise. The effectiveness of the method is further verified by the tank model experiments. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research paper introduces a novel double-stator (DS) hybrid-excited (HE) flux reversal permanent magnet (FRPM) machine with Halbach PM arrays, specifically designed for electric vehicle (EV) traction applications. The study commences with a detailed description of the operating principle of the proposed machine. The machine design incorporates a comprehensive sensitivity analysis of its structural design variables, followed by a multi-objective optimization utilizing the NSGA-II algorithm. The results clearly show that the proposed DS-HE-FRPM machine outperforms the benchmark in several key aspects while adhering to the same PM volume constraint. It exhibits significantly improved back electromotive force, and substantially lower cogging torque. Notably, when compared to the benchmark, the optimized structure of the DS-HE-FRPM machine highlights a notable 22.4% enhancement in electromagnetic torque, while effectively keeping torque ripple at a low level. The underlying reasons behind these notable improvements of the proposed machine structure are explained in detail, providing a comprehensive understanding of their rationales. These findings suggest that the innovative DS-HE-FRPM machine holds significant torque potential, which could greatly enhance the performance and efficiency of EVs. This represents a highly promising development in the field of traction applications.

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To explore the influence of the excitation current in the rotor magnetic shunt hybrid excitation synchronous motor (HESM) on the vibration and noise of the motor, the finite element analysis of the hybrid excitation motor was carried out by using ANSYS Workbench software and noise sources for analysis. Firstly, air-gap flux density at different excitation currents and density vector diagrams are studied. Secondly, radial electromagnetic force’s order and frequency characteristics under different excitation currents are discussed. Finally, the modal analysis of the stator of the motor is carried out. The motor’s vibration response and noise variation under different excitation current conditions are summarized. The simulation analysis and experimental verify that the motor’s vibration response and noise increase obviously when the excitation current is significant, and the vibration acceleration of different orders increases.

In order to research vibration and noise of TMPS-HESM. The Magnetic pole eccentricity TMPS-HESM is established. The order and frequency characteristics of radial electromagnetic force are discussed The vibration and noise coupling model is built by ANSYS Workbench simulation platform. The vibration response and noise variation are discussed. The results show that magnetic pole eccentricity can effectively reduce air gap flux density harmonic content, and third harmonic is significantly decreased. The excitation current will significantly affect the harmonic (8,2f1), (16,4f1), (0,12f1) components of radial electromagnetic force of magnetic pole eccentricity TMPS-HESM. Although the (0,12f1) component is not the same order of magnitude as other components, it will still worsen the vibration noise of the motor.

Background: The direct-drive linear motor system is usually a low-damping system, which will cause residual vibration and deteriorate the accuracy of the equipment especially in the high-speed start-stop motion. Purpose: By employing an eddy current damper (ECD), the residual vibration can be effectively reduced. However, the ECD secondary is normally made of a pure copper plate with low magnetic permeability, resulting in low airgap magnetic density and therefore small damping force. In this paper, a dual-sided hybrid excitation ECD which implements high-conductivity and high-permeability plate as the secondary is proposed to enhance the vibration suppression for the linear motor system. Methods: An analytical model is developed to quantitatively analyze the relationship between the damping force and the secondary thickness. Three dimensional finite element analysis (3D FEA) is employed to investigate the effects of different secondary materials and the secondary layer thicknesses on ECD performance. Results and Conclusion: Experiments are conducted to evaluate the damping force and the vibration suppression effect of the designed ECD. Compared with the pure copper secondary under the same secondary dimensions, the damping force is increased by 30.5% with the copper-steel-copper secondary, and the peak amplitude of the position error and the settling time of the system are reduced by 1.94 times and 1.80 times, respectively. [ABSTRACT FROM AUTHOR]

Featured Application: The research findings can be applied in the design of generators of various vehicles, in particular synchronous homopolar generators. Electric machines with hybrid excitation have increased torque density while maintaining a wide range of speed control. This article presents the results of the optimal design of a synchronous homopolar generator (SHG) with ferrite magnets on the rotor and excitation winding on the stator for passenger cars. The use of ferrite magnets on the rotor of a synchronous homopolar generator makes it possible to use the stator surface more efficiently, which in turn increases energy efficiency and reduces the dimensions of the generator. At the same time, the excitation winding on the stator provides a reliable brushless design and the ability to control the excitation flux. The problem of long-time calculation of the three-dimensional SHG structure, which is especially relevant when using multi-iterative computer optimization, is solved by using the computationally efficient Nelder-Mead method and a simplified SHG model using two-dimensional finite element analysis. It is also clear that the low torque ripple of SHG with ferrite magnets with two stator-rotor stack combinations (SRSC) is largely provided by the fact that the torque ripples of individual SRSCs are in antiphase. The problem of considering the magnetic properties of magnetic core sections made of structural low-carbon steel is discussed. It has been found that with an increase in both the saturation level of the magnetic circuit and the magnetomotive force (MMF) of the SHG excitation winding, resistance to irreversible demagnetization of ferrite magnets on the rotor can be increased by increasing their height. In addition, it is shown that there is a significant increase in performance when using the hybrid excitation, in comparison with the conventional SHG design without magnets. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the permanent magnet on the rotor of high-speed permanent magnet synchronous machine (PMSM) is easy to be damaged by centrifugal force and easy to be affected by high temperature, which leads to non-reverse demagnetization, a new concept of high-speed permanent magnet synchronous machine with hybrid excitation on the stator (PMSMHES) is introduced in this paper. And its structure and electromagnetic parts are designed. PMSMHES uses a hybrid excitation method, so that the air gap magnetic field of the permanent magnet motor can be adjusted, thereby solving the problem of a narrow constant power range when the motor is running. Secondly, the equivalent magnetoelectric model of PMSMHES is proposed and the calculation method of related parameters is proposed. Finally, the rationality of the equivalent model and the calculation method of each parameter is verified by finite element simulation.

This article proposes a series of split-tooth stator permanent magnet (PM) Vernier machines with zero-sequence current excitation, which integrates enhanced torque density and flux adjustment capability. The key is to design the split tooth to exert desired dual magnetic field modulation effect so as to efficiently utilize the hybrid magnetic fields by the PM and zero-sequence current. Meanwhile, with the split-tooth design, the paralleled flux paths are achieved to offer improved flux regulation capability and reduced PM demagnetization risk. In this article, the machine topologies and operation principle are introduced. Hybrid excitation magnetic field is analyzed with the consideration of dual magnetic field modulation of split-tooth structure. Influences of split tooth and PM on torque and flux regulation capability are analyzed. Electromagnetic performances of the proposed machine are analyzed and compared. A prototype is manufactured and tested to validate the theoretical analysis. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the cogging torque of tangential magnetizing parallel structure hybrid excitation synchronous motor (TMPS-HESM) rises sharply when the excitation current increases. Maxwell & Workbench & optiSLong co-simulation tool was used for research. Firstly, the length and width of the permanent-magnet, rotor eccentricity, and stator parameters are parameterized. The multi-objective optimization is carried out by using particle swarm optimization (PSO). Secondly, through sensitivity analysis, the influence degree of different input parameters on cogging torque, average torque and torque pulsation is discussed. Then, the quadratic regression model of high sensitivity parameters and cogging torque, average torque and torque pulsation is established respectively. Finally, entropy technique for order preference by similarity to an ideal solution (TOPSIS) method is used to select the optimal solution from pareto solution set. The results show that the cogging torque and torque ripple of the optimized motor are suppressed obviously, and the average torque is also improved. [ABSTRACT FROM AUTHOR]

Hybrid excitation primary permanent magnet linear motor has the dual advantages of high thrust density of primary permanent magnet linear motor and the flexibility on adjusting the air gap magnetic field of hybrid excitation motor. In this paper, two new 36/4 hybrid excitation primary permanent magnet linear motors with different secondary structures are proposed. Based on the detailed introduction of the motor topology and operation mechanism, the structural parameters are optimized, and the pole arc coefficient of the primary pole shoe and the secondary are finally determined to be 0.4. The secondary is magnetoresistive, and the final thrust adjustment range is about 16.8% under the conditions of optimal armature current and current lead angle. The temperature field of the motor in the magnetizing state is analyzed. The results show that the temperature of the motor decreases gradually from the center to both sides after 7200 s of operation of the new hybrid excitation structure, while the permanent magnet will not be demagnetized permanently. It shows an acceptable reliability.

Aiming at the engineering limitations of traditional ship vibration online monitoring and noise prediction methods, this paper proposes a method for online monitoring and underwater radiation noise prediction of cabin structures’ vibration and noise under hybrid excitation of sound and force. The method first constructs the condition test model; based on OTPA technology, the “acoustic-vibration” transfer function between sound and vibration monitoring points in the cabin and the “acoustic/vibration-acoustic” transmission network inside and outside the cabin structure are obtained. Secondly, based on the “acoustic-vibration” transfer function, the online vibration and sound monitoring data are decoupled and processed to obtain the modified vibration and sound monitoring data. Finally, the near-field radiation noise on the conformal hologram surface outside the cabin is predicted based on the “acoustic/vibration-acoustic” transmission network, and the far-field radiation noise of the cabin structure is predicted by the wave superposition method. In this paper, the contribution law of external radiation noise and the coupling characteristics of the monitoring information under the hybrid excitation of sound and force are analyzed theoretically, and the decoupling method of coupling information is also studied. This method makes up for the problem of missing underwater radiation noise caused by sound excitation in traditional vibration monitoring, and it can effectively improve the prediction accuracy of underwater radiation noise. The effectiveness of the method is further verified by the tank model experiments.

Aiming to design a generator with high reliability, high efficiency, and especially a constant output voltage over a wide speed range for hybrid electric vehicles (HEVs), this paper proposes a novel topology of a hybrid excitation doubly salient generator with separate windings (HEDSGSW). The topology herein utilizes a hybrid excitation type of PMs and DC windings to generate parallel magnetic circuits. In addition, PMs are embedded in the magnetic bridge to insulate the excitation windings with armature windings. This design can achieve compactness, efficiency, and especially constant output capability over a wide speed range. The geometry and flux regulation principles, including magnetic flux circuits, are elaborated. After comparing three power generation modes, the most suitable mode, namely, the doubly salient generation 2 (DSG2) mode, is confirmed to ensure a stable voltage output performance. Then, considering the non-uniformity effect of the stator and rotor slots, the no-load back electromotive force (EMF) expressions are derived based on the EMF to air-gap relative permeance method. Furthermore, a 1 kW HEDSGSW FEA model, with an output voltage of 42 V and a rated speed of 6000 rpm, is built to demonstrate the effectiveness of the proposed method. Finally, the operating properties of the HEDSGSW, such as no-load characteristics and adjustment characteristics, are analyzed to further verify the rationality of its magnetic flux circuit and the flexibility of the excitation regulation capability. [ABSTRACT FROM AUTHOR]

With the wide use of new energy vehicles, the research and development of high‐performance generators become more important. The claw pole machine is very suitable to be used as an automobile generator because of its unique characteristics. However, its development is limited by the disadvantage of abundant harmonic content, especially when used with fractional slot concentrated winding layout. A novel dual‐direction hybrid excitation generator (DDHEG) is proposed in this paper. It has dual 3‐phase winding layout to reduce spatial subharmonic magnet motive force (MMF). Also, it uses dual 3‐phase rectifier bridge circuit to reduce armature current, so as to reduce copper loss. It uses rotor sleeve to reduce the eddy current loss in the rotor and permanent magnets (PMs) caused by higher order harmonics. It has hybrid excitation from both directions to improve the efficiency and terminal voltage. The basic characteristics of DDHEG are analyzed by finite element analysis (FEA) method. The highlights of the proposed DDHEG are illustrated. The simulation results and experimental results reveal that the proposed DDHEG can effectively adjust the terminal voltage at different loads and reduce the harmonics and loss to a satisfied degree. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Hybrid excitation is a technology that combines the advantages of field windings and permanent magnets for inducing magnetic flux. This article studies the benefits of hybrid excitation and provides an outlook on their possible applications, such as wind power generators and electric vehicle motors. Compared to permanent magnet-based machines, hybrid excitation gives a variable flux while still using the advantage of the permanent magnets for a portion of the flux. This article also looks into some different categories of machines developed for hybrid excitation. The categories are based on the reluctance circuit, the relative geometrical location of the field windings relative to the permanent magnets, or the placement of the excitation system. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of stator/rotor pole number combinations and permanent magnet (PM) numbers on electromagnetic performance of consequent-pole hybrid excited flux reversal machines (CP-HEFRMs), which have different numbers of PM poles and iron poles and concentrated AC and DC windings on the stator and a salient pole rotor. PMs in the slots of one stator pole are magnetized radially in the same direction, while opposite on adjacent stator poles. Magnetic field paths of DC, PM, and hybrid excitations are investigated. The phenomenon of flux cancellation, i.e., PM and DC MMFs in CP-HEFRMs are of opposite polarities in the flux-enhancing operating mode, is revealed and verified, for the first time, as the key feature that makes CP-HEFRMs different from other hybrid excited machines. Consequently, the saturation in stator pole and yoke can be mitigated and hence the overload capability of DC excitation is enhanced, which is verified by finite element analysis (FEA). Global optimizations are utilized to obtain the optimal rotor and stator pole number combinations and PM numbers for each stator pole. Torque, torque ripple, inductance, unbalanced magnetic force, and flux regulation capability are compared for different PM numbers and rotor pole numbers. Comparisons are made on consequent-pole and non-consequent-pole topologies in terms of torque capacity, flux regulation capability, and PM consumption to further illustrate the advantages of consequent-pole topology. A prototype machine is built and tested to validate the analyses. [ABSTRACT FROM AUTHOR]

The transverse flux tubular linear machine (TF-TLM) has merits of high power density and efficiency. However, excited by constant permanent magnet (PM), it is hard for TF-TLM to regulate its flux effectively, which restricts its further application in wave energy conversion (WEC). In contrast, the inherent higher order harmonics existing in the induced voltage may cause the additional loss and produce overvoltage, which should be eliminated to prompt power quality. Therefore, to strengthen the flux regulation capability of TF-TLM and improve the generated power quality, a novel hybrid-excited TF-TLM (HE-TFTLM) with complementary structure is proposed in this article. The key is that a parallel and complementary structure is constructed for hybrid excitations of both dc windings and PMs installed on the stator to enhance the flux regulation capability and eliminate the even-order harmonics in the induced voltage. In addition, the stator consequent-pole design boosts the output thrust density. According to the 3-D finite element analysis (FEA) results, output thrust force reaches 279.14 N, and the power density of the proposed machine can be effectively improved to 154 kW/m3 at rated excitation. [ABSTRACT FROM AUTHOR]

A comparative study of new partitioned stator hybrid excitation axial flux switching permanent magnet (HEAFSPM) motors with different partitioned excitation stator topologies for in-wheel traction applications is presented in this paper. The realization approaches of the partitioned stator HEAFSPM motor are discussed, and the motor topology with windings and permanent magnets (PMs) separately setting on different stators is selected in view of the advantageous structure for thermal management. On this basis, two partitioned excitation stator topologies including C-type tooth core and T-type tooth core stator configuration are proposed, and the air-gap flux modulation and flux regulation principle of the motors are analyzed. In addition, the design method of the partitioned stator HEAFSPM motor considering the effect of hybrid excitation sources is provided, and the two motors with different tooth cores are designed respectively. Meanwhile, for a fair comparison, the multiple objectives optimization method coupled with the sensitivity analysis is employed to optimize the two motors. The electromagnetic performances, anti-demagnetization capability, and flux regulation performance of the two motors are all investigated in detail. Finally, two prototype motors are fabricated and tested. Both the theoretical analysis and experimental results verify the effectiveness and reasonability of the motor. [ABSTRACT FROM AUTHOR]

Electric vehicle (EV) generators have characteristics of small volume and high power density, which leads to high temperature rise. The temperature rise will directly influence the service life and reliability of the generator, so thermal analysis of EV generators is necessary in machine design. This paper carries out thermal analysis of a dual-axis-direction hybrid excitation generator (DHEG) used in EVs. The lumped parameter thermal network (LPTN) method is used to build the three-dimensional thermal model of DHEG. Compared with finite element analysis, LPTN can significantly reduce the simulation time while ensuring a good accuracy. Then, the influence of heat dissipation rib on DHEG temperature rise is studied. The results prove that adding heat dissipation rib on the enclosure surface can effectively reduce the maximum temperature of DHEG. [ABSTRACT FROM AUTHOR]

This article proposes and investigates two asymmetric consequent-pole hybrid excited flux reversal machine (AS-CP-HEFRM) topologies, which have same numbers of iron poles and permanent magnets (PMs) with concentrated ac and dc windings on each stator pole and a salient pole rotor. If PM number on one stator pole is larger than 1, PMs are magnetized radially in the same direction on one stator pole, while opposite on adjacent stator poles. The phenomenon of the phase shift between the flux linkages of dc and PM excitations in the AS-CP-HEFRMs is revealed for the first time, which will weaken the regulation of dc excitation field to PM produced field. The elimination condition of the phase shift is derived and verified by finite-element analysis in this article, which can be considered as design guidelines in AS-CP-HEFRMs. Airgap magnetic field space harmonics of AS-CP-HEFRM are also investigated and verified by finite-element analyses. Meanwhile, the relationship between the rotor pole number and the stator pole arc (PM ratio) is derived and verified by global optimization based on genetic algorithm for maximum average torque. The influence of stator/rotor pole number combinations is also studied and compared in terms of torque, torque ripple, and flux regulation capability. The torque components produced by airgap magnetic field space harmonics are calculated and compared. A prototype has been built and tested to validate the finite element calculations. [ABSTRACT FROM AUTHOR]

Variable speed, permanent magnet synchronous machines with hybrid excitation have attracted much attention due to their flux-control potential. In this paper, a design of permanent magnet axial flux machines with iron poles in the rotor and an additional electrically controlled source of excitation fixed on the stator is presented. This paper shows results pertaining to air-gap flux control, electromagnetic losses, electromagnetic torque, back emf and efficiency maps obtained through field-strengthening and weakening operations and investigated by 3D finite element analysis. Moreover, the temperature distribution of the machine was analyzed according to the fluid–thermal coupling method. The presented machine was prototyped and experimentally tested to validate the effectiveness of numerical models and achieved results. [ABSTRACT FROM AUTHOR]

Electric machines with hybrid excitation have increased torque density while maintaining a wide range of speed control. This article presents the results of the optimal design of a synchronous homopolar generator (SHG) with ferrite magnets on the rotor and excitation winding on the stator for passenger cars. The use of ferrite magnets on the rotor of a synchronous homopolar generator makes it possible to use the stator surface more efficiently, which in turn increases energy efficiency and reduces the dimensions of the generator. At the same time, the excitation winding on the stator provides a reliable brushless design and the ability to control the excitation flux. The problem of long-time calculation of the three-dimensional SHG structure, which is especially relevant when using multi-iterative computer optimization, is solved by using the computationally efficient Nelder-Mead method and a simplified SHG model using two-dimensional finite element analysis. It is also clear that the low torque ripple of SHG with ferrite magnets with two stator-rotor stack combinations (SRSC) is largely provided by the fact that the torque ripples of individual SRSCs are in antiphase. The problem of considering the magnetic properties of magnetic core sections made of structural low-carbon steel is discussed. It has been found that with an increase in both the saturation level of the magnetic circuit and the magnetomotive force (MMF) of the SHG excitation winding, resistance to irreversible demagnetization of ferrite magnets on the rotor can be increased by increasing their height. In addition, it is shown that there is a significant increase in performance when using the hybrid excitation, in comparison with the conventional SHG design without magnets.

Direct drive wave energy conversion (DD-WEC) is a typical low-speed long-stroke application. Harvesting wave energy presents enormous challenges, because wave energy naturally exists in the form of extremely low speed, high force, or torque motion. However, the frequency of flux linkage in field-modulated machine can be increased by the magnetic gear effect, and the output voltage and power density can also be effectively enhanced. In this article, based on the field-modulated principle, a field-modulated transverse flux linear generator (FM-TFLG) is proposed. Different combinations of permanent magnet (PM) number, slot number, and translator number are selected and their performances are compared and analyzed. Results show that the electric frequency is enhanced as the modulation ratio increases. Compared with 18/12/17 (PM number/slot number/translator number) topology, 12/12/11 FM-TFLG has advantages of lower thrust ripple and total harmonic distortion (THD) of back electromotive force (EMF), higher thrust/power density, and efficiency. The proposed 12/12/11 FM-TFLG is a good candidate for DD-WEC. [ABSTRACT FROM AUTHOR]