Permanent Magnet Type Research Articles

Analysis of Permanent Magnet Demagnetization during the Starting Process of a Line-start Permanent Magnet Synchronous Motor

Neodymium (NdFeB) rare earth Permanent Magnets (PMs) are widely used in the manufacturing of Line-Start Permanent Magnet Synchronous Motors (LSPMSMs). During the initial startup of LSPMSMs, irreversible PM demagnetization often occurs. This research provides a thorough examination of the PM demagnetization process during the initiation of a 15-kW, 3000-rpm LSPMSM, which was converted from a squirrel-cage Induction Motor (IM) featuring a 3-bar PM. Utilizing Ansys/Maxwell2D software for simulations and conducting experiments, this study reveals that upon starting the LSPMSM, demagnetization occurs at the two outermost PM pairs. This leads to unstable motor operation at synchronous speed, significant current fluctuations, and a substantial decrease in performance. The findings suggest that to ensure effective LSPMSM operation, it is crucial to either restrict frequent restarts or select an appropriate PM type to prevent partially irreversible demagnetization, thereby enhancing power efficiency.

Improvement on Electromagnetic Performance of Axial–Radial Flux Type Permanent Magnet Machines by Optimal Stator Slot Number

To achieve the objective of high torque, a high utilization rate of PMs, and flexible flux regulation capability of the permanent magnet (PM) machine, an axial–radial flux type permanent magnet (ARFTPM) machine was studied in this paper. The working principle of the ARFTPM machine is analyzed by illustrating the flux paths. Then, the influence of stator slot number on the flux regulation capability and torque is studied. A full comparison of the main parameters and electromagnetic performances of the ARFTPM machine with different stator slot numbers is presented, including winding coefficient, back electromotive force (EMF), cogging torque, average torque, and torque-angle characteristics. The optimal stator slot number was obtained. Finally, the 12-slot/10-pole prototype machine is manufactured and tested to validate the simulation data and theoretical analysis.

Magnetic circuit optimisation and actuator suspension experiment of the 6‐DOF magnetic suspension platform for mini/micro LED

AbstractTo improve the speed of mass transfer, a magnetic suspension platform (MSP) is used to transport the display chips. A novel 6‐DOF MSP is proposed in this paper. An improved Halbach array is used to supply the magnetic flux density. Two types of permanent magnets are utilised in the improved Halbach array. The smaller permanent magnet serves to consolidate the magnetic flux density, thereby enhancing the uniformity of the magnetic field. The finite element method is employed to analyse how variations in angle impact both the strength and uniformity of the magnetic flux density. The results show that the magnetisation direction of 45° is the most effective in terms of improving the uniformity and strength of the magnetic density. Finally, a 6‐DOF MSP prototype is manufactured. A magnetic density measurement experiment and a stable suspension experiment for the actuator are conducted. The results indicate an enhancement in the uniformity of the magnetic field within the air gap. Additionally, the maximum suspension positioning accuracy of the actuator is about 750 nm.

Operational Status and Future Plan of Proton Linear Accelerator at KOMAC

Since the second half of 2013, Korea Multi-purpose Accelerator Complex (KOMAC) has been supporting user beam service by using a 100-MeV proton linac and several beam line facilities. Proton beam service fields include various applications and research programs, such as material science, bio-medical science, semiconductor applications as well as nuclear physics and basic science. The 100-MeV linac is composed of an injector based on a 50-keV microwave ion source and two-solenoid LEBT (low energy beam transport), a 3-MeV RFQ with four-vane structure and conventional drift tube linac (DTL), where proton beam is accelerated from 3 MeV to 100 MeV. As the operation period of the proton accelerator exceeds 10 years and the cumulative operating time surpasses 30,000 hours, we judge that it is an opportune time to establish a long-term plan to prepare for the aging of the accelerator. To replace the currently operating RFQ, which shows degradation in performance (especially the beam transmission), we design a new RFQ with some modifications. For DTL, we are supposed to change the quadrupole magnet inside each drift tube from electromagnet type to permanent magnet type because the electromagnet has shown some trouble in view of long term stability. To leap forward in device and utilization technologies, we complete the construction of new facility of a Beam Test Stand (BTS) with a structure similar to the beam injection system (ion source, LEBT, RFQ) of the 100 MeV linear accelerator. We plan to actively conduct beam physics and accelerator research using this facility. Moreover, we are supposed to upgrade the proton linac to 1 GeV for spallation neutron source applications, which will be a long-term plan. In short term, we take phased approach with focusing the first phase at 200 MeV energy upgrade.

Design & Prototype development of 2.2 kW Axial Flux PCB Stator Motor

This paper presents the design and prototype development of 2.2 kW Axial flux PCB stator motor, compared to the conventional permanent magnet type of electric motors. This construction eliminates the iron core, as a result there is a reduction of weight, cogging torque, noise and increase in efficiency. Analytical design was done, and prototype is developed with 8-layer PCB board with 6 Oz of cu is used to build the required power.

Magnetic Fields and Equipment for Studying the Magnetoplasticity of Metals

The phenomenon of magnetoplasticity of metallic materials is presented. Methods of magnetic processing using constant and variable magnetic fields are described. The characteristics of constant and alternating magnetic fields used in experimental studies are compared. A method for calculating the magnetic field in the gap between the electromagnet cores is described. The influence of the gap between the cores of an electromagnet and the current strength in the winding of its coils on the induction of the magnetic field has been studied. Schemes of the perpendicular and parallel orientation of the samples and their main axis of deformation relative to the magnetic field lines are presented. The composition of the equipment for creating the effect of magnetoplasticity in laboratory testing of metal samples is described. The types of permanent magnets, electric inductors and magnetic field concentrators are given. Prospects for the development of experimental research on magnetoplasticity are determined.

Development of High-Temperature Permanent Magnet Synchronous Motor for Autonomous Robotic Navigation: A Design and Finite Element Analysis Approach

The traditional industrial robots come with the prime mover, i.e. Electric Motors (EM) which ranges from a few hundred too few kilo watts of power ratings. However, for autonomous robotic navigation systems, we require motors which are light weighted with the aspect of high torque and power density. This aspect is very critical, when the EMs in robotic navigations are subjected to harsh high temperature survival conditions, where the sustainability of the performance metrics of the electromagnetic system of the EMs degrade with the prevailing high temperature conditions. Hence, this research work address and formulate the design methodology to develop a 630 W High Temperature PMSM (HTPMSM) in the aspect of high torque and power density, which can be used for the autonomous robotic navigation systems under high temperature survival conditions of 200°C. Two types of rotor configurations i.e. the Surface Permanent Magnet type (SPM) and the Interior Permanent Magnet type (IPM) of HTPMSM are examined for its optimal electromagnetic metrics under the temperature conditions of 200°C. The 630 W HTPMSM is designed to deliver the rated torque of 2 Nm within the volumetric & diametric constraints of D x L which comes at 80 x 70 mm at the rated speed of 3000 rpm with the survival temperature of 200°C with the target efficiency of greater than 90%. The FEM based results are validated through the hardware prototypes for both SPM and IPM types, and the results confirm the effectiveness of the proposed design methodology of HTPMSM for sustainable autonomous robotic navigation applications.

Analysis of Multi-Objective Optimization Design of Interior Double Radial and Tangential Combined Magnetic Pole Permanent Magnet Drive Motor for Electric Vehicles

A new type of interior combined pole permanent magnet drive motor is proposed in this paper, which aims to improve the power and comfort of electric vehicles. In view of the complex magnetic circuit structure and rich harmonic magnetic field of the motor, the initial magnetic pole parameters of the rotor are determined by the equivalent magnetic circuit method. Then, aiming at the complex magnetic circuit and rich harmonic magnetic field, a multi-objective optimization method based on the Taguchi method and response surface method is proposed to reduce the cogging torque, high harmonic content in air gap magnetic flux density and increase the output torque. Based on the finite element analysis of the electromagnetic performance of the new type interior combined magnetic pole permanent magnet drive motor before and after optimization, it can be seen that the improved rotor structure can effectively reduce the torque ripple and increase the torque density. Finally, a prototype was developed and experiments were conducted, and experimental results verified the correctness of the proposed multi-objective optimization algorithm.

RANCANG BANGUN GENERATOR MAGNET PERMANEN FLUKS AKSIAL PADA PROTOTYPE PEMBANGKIT LISTRIK TENAGA BAYU (PLTB) SUMBU VERTIKAL

Axial flux permanent magnet generators are easy to manufacture because only the rotor and stator are aligned. Axial flux generators are one of the right choices for wind power plants due to the large number of magnetic poles, high electrical power density, and easy-to-increase power capacity. The axial flux type permanent magnet generator is designed with a speed of 600 rpm, a frequency of 50 Hz, a voltage of 12 V, a power of 7 Watts, 1 phase, 10 pairs of Neodymium Iron Boron (NdFeB) type magnetic poles, and 5 copper wire coils measuring 0.6 mm in diameter with a total of 301 turns. This vertical-axis wind farm test uses an axial flux permanent magnet generator with a 5? resistor load and is assisted by a blower. The blower is used to get a constant turbine rotation in accordance with the results of wind speed measurements taken for 3 days on the rooftop of the electrical engineering lecture building, namely the wind speed range of 3-5 m/s. Based on these tests, the generator is able to produce a voltage of 1.5 V, a current of 0.2 A, a power of 0.27 Watt, and a generator efficiency level of 0.63% at a wind speed of 3 m/s. It also produces a voltage of 4.4 V, a current of 0.7 A, a power of 2.77 Watt, and a generator efficiency level of 0.97% at a wind speed of 5 m/s.

PENGARUH VARIABEL CELAH UDARA TERHADAP FLUKS MAGNET PADA GENERATOR PERMANEN MAGNETIK AXIAL FLUKS

Generators that use permanent magnets do not require initial excitation to produce voltage. where the generator design is an axial flux type using a ceramic type permanent magnet (NdFeB), and uses two flanking stator rotors. For electricity use, the AC voltage is changed to DC voltage using a rectifier for charging the accumulator. The air gap in an axialflux generator is the distance between the rotor and stator. The air gap is also a place for the magnetic field to move through the coils in the stator which ultimately produces a magnetic flux value which will influence the amount of induced voltage produced. The faster the rotation produced, the greater the voltage produced, but the frequency value will also increase, so that this generator is only limited to 400 rpm rotation, at a frequency value of 50 Hz, producing an effective voltage of ± 22 V with an air gap distance ( δ) is 2 mm, the frequency measurement has an error of 10-20 Hz and an error percentage of 5-10%, with the results of the induced current measurement having the same voltage

Design analysis of intelligent controller to minimize harmonic distortion and power loss of wind energy conversion system (grid connected)

<p>The controlling of internal parametric variations in addition to the non-linearity of a large conversion system of wind energy (WECS) is prime challenges to make the most of the generated energy, with less power loss and secure the proficiency (η) integration conventional grid. An adjustable speed control structure of grid-connected conversion system of wind energy (WECS), with the help of a Permanent Magnet Type Synchronous Generator with intelligent controller minimizes the power loss. The control system incorporates a pair of controllers dedicated to the converters of both the generator and grid edge. The controller at the generator side has the main function is to optimize power that can be withdrawal from the wind by intelligently regulating the turbine’s rotational speed. Meanwhile, the grid edge converter effectively manages active and reactive power by manipulating the d & q-axis current components, respectively. This paper discusses about the improvement in performance of the system when using Neuro-Fuzzy system as compared to Neural Network and Management of energy deliver system via direct control method. The findings reveal that the training time for Artificial Neural Networks (ANNs) is substantial, leading to the Neural Network-Direct Power Contol (NN-DPC) approach being the slowest option among the alternatives. Additionally, the NF-DPC system is less time-consuming than the NN-DPC, with a recorded duration of 24 seconds compared to the NN-DPC’s observation of 8 min and 5 s. However, it is worth noting that the NF-DPC system is somewhat more time-intensive than Common-Direct Power Contol (C-DPC).</p>

Perbandingan Sistem Levitasi Magnetik Ems dan Eds Untuk Maglev Indonesia

Maglev trains are considered for urban transport and intercity transport systems. On low-medium speed Maglev trains, the operating routine is shorter than that of high-speed trains. Therefore, EMS and LIM technologies are preferred from the point of view of construction costs. However, in high-speed operation, EDS and NGO technologies are preferred for handling, and reliability. In addition, as the development of high-temperature superconductors and new types of permanent magnets develop, stronger and more cost-effective magnetic energy will be used for Maglev trains. The authors believe this technology can be utilized not only for railway applications but also aircraft launch systems and spacecraft launch systems. The need for a new and improved transportation system prompted many countries to be interested and seek to develop Maglev railways. However, although Maglev trains have been studied and developed for approximately half a century, few countries have the knowledge and expertise to do so. This review paper attempts to describe the current complete system in detail and summarizes the basic core technologies of Maglev trains from an electrical engineering point of view. The research hopes to be useful for people interested in this to assimilate Maglev train technology including magnetic levitation, propulsion, guidance, and power supply systems.

A novel permanent magnet vibration isolator with wide stiffness range and high bearing capacity

Quasi-zero stiffness (QZS) vibration isolators have attracted extensive attention because of their excellent performance in low-frequency vibration isolation and high bearing capacity. However, its practical engineering application remains challenges due to the magnitude and adaptability of the negative stiffness. This paper proposes a permanent magnet type variable stiffness (PMVS) mechanism with a wide stiffness range from negative to positive. Based on the semi-analytical model of magnetic force, the QZS isolator composed of the spiral spring in parallel with the PMVS mechanism is developed, which has both stiffness adjustment and load adaptability. The nonlinear dynamic equation with 5th polynomial restoring force is established then solved by the harmonic balance method (HBM). The dynamic behaviours is investigated and validated through the experimental prototype and good isolation performance is observed. Building upon the wide stiffness adjustment and large magnitude of the PMVS mechanism. the proposed isolator achieves a stiffness range of 4.15–153.45 N/mm under a safe load up to 120 kg, which implies that the natural frequency of the isolator can reach an ultralow value of 0.93 Hz within the safe load (120 kg).

Research on magnetic regulation characteristics of axial-radial flux type permanent magnet synchronous machine

Research on magnetic regulation characteristics of axial-radial flux type permanent magnet synchronous machine

Using Reluctance Torque Theory in Spoke Type Permanent Magnet Vernier Motors to Increase Average Torque

Using Reluctance Torque Theory in Spoke Type Permanent Magnet Vernier Motors to Increase Average Torque

Novel Magnetic Field Modeling Method for a Low-Speed, High-Torque External-Rotor Permanent-Magnet Synchronous Motor

In view of the unstable electromagnetic performance of the air gap magnetic field caused by the torque ripple and harmonic interference of a multi-slot and multi-pole low-speed, high-torque permanent magnet synchronous motor, we propose a simplified model of double-layer permanent magnets. The model is divided into an upper and a lower subdomain, with the upper subdomain being an ideal circular ring and the lower subdomain being a segmented sector ring. Moreover, we develop an exact analytical model of the motor that predicts the magnetic field distribution based on Laplace’s and Poisson’s equations, which is solved using the method of separating variables. Taking a 40p168s low-speed, high-torque permanent magnet synchronous motor as an example, the accuracy of the model is verified by comparison with an ideal circular ring model, a segmented sector ring model, and the finite element method. Based on the proposed simplified model, three combined permanent magnets considering both edge-cutting and polar arc cutting structures are proposed, which are chamfered, rounded, and rectangular combinations. Under the premise of a consistent edge-cutting amount, the electromagnetic characteristics of the three combination types of permanent magnets are compared using the finite element method. The results show that the electromagnetic characteristics of the chamfered combination PM are superior to those of the other two combinations. Finally, a prototype is manufactured and tested to validate the theoretical analysis.

An Improved Design for Steady-State Characteristic of Permanent Magnet Type Step Motor with Claw Poles by 3D FEM

An Improved Design for Steady-State Characteristic of Permanent Magnet Type Step Motor with Claw Poles by 3D FEM

Torque Ripple and Mass Comparison between 20 MW Rare-Earth and Ferrite Permanent Magnet Wind Generators

This article investigates the comparison between two configurations of 20 MW offshore synchronous wind generators using ferrite and rare-earth permanent magnets. The optimization-based comparison concerns the torque ripple and active mass, which are two crucial criteria for offshore wind generators. Both generators adopt surface-mounted permanent magnet type with direct-drive technology to avoid problems associated with the gearboxes. The result shows that at the full-load condition, the ferrite permanent magnet generator can reduce the torque ripple to as much as 0.12%, while the rare-earth counterpart can be about 2.5 times lighter than the former one.

A Study on Maximum Power Point Tracking for Wind Power Generations

This paper presents a study on maximum power point tracking for a wind turbine generation (WTG). The general structure of a WTG will be introduced, including mechanical and electrical conversion blocks, to make clear about the role of all units. Moreover, mathematical models of both turbine and generator type permanent magnet synchronous generator (PMSG) will be presented to simulate and evaluate the operation of WTG. Working regions of the wind turbine corresponding to different values of wind speed and contents of some techniques to determine maximum power point will be made detailed. Hill climb search (HCS) is chosen to simulate and analyzed deeply to evaluate the ability to apply to real applications. Simulation results are carried out by MATLAB/Simulink software. By using a variation scenario of wind speed, the role of power converter and HCS controller will be presented in some simulation results about power and current at output terminals of the generator to show the ability to track instantaneous maximum power point. Research results show the high effectiveness and availability of HCS technique in real wind power system. Keywords: Maximum power point, Maximum power point tracking, Wind turbine, Wind generator, Wind speed, PMSG.

Development and comparison of double-stator memory machines with parallel hybrid magnets

PurposeThis paper aims to further develop stator permanent magnet (PM) type memory machines by providing generalized design guidelines for double-stator memory machines (DSMMs) with hybrid PMs. This paper discusses the design experience of DSMMs and presents a comparative study of radial magnetization (RM) and circumferential magnetization (CM) types.Design/methodology/approachIt begins with an introduction to RM and CM operating principles and magnetization mechanisms. Then, a comparative study is conducted for one of the RM-DSMM rotor pole pairs, inner and outer stator clamping angles and low coercive force PMs thickness. Finally, the two machines’ finite element simulation performance is compared. The validity of the proposed machine structure is demonstrated.FindingsIn this paper, the double-stator structure is extended to parallel hybrid PM memory machines, and two novel DSMMs with RM and CM configurations are proposed. Two types of DSMMs have PMs and magnetizing windings on the inner stator and armature windings on the outer stator. The main difference between the two is the arrangement of PMs on the inner stator.Originality/valueConventional stator PM memory machines have geometrical space conflicts between the PM and armature windings. The proposed double-stator structure can alleviate these conflicts and increase the torque density accordingly. In addition, this paper contributes to comparing the arrangement of hybrid PMs for DSMMs.