scholarly journals Permanently split capacitor motor-study of the design parameters

2017 ◽  
Vol 68 (5) ◽  
pp. 339-348
Author(s):  
Vasilija Sarac ◽  
Goce Stefanov
Keyword(s):  
Flux Density ◽  
Analytical Model ◽  
Fem Analysis ◽  
Optimization Method ◽  
Air Gap ◽  
Analytical Models ◽  
Design Parameters ◽  
Magnetic Flux Density ◽  
Split Capacitor ◽  
Motor Model

Abstract Paper analyzes the influence of various design parameters on torque of permanently split capacitor motor. Motor analytical model is derived and it is used for calculating the performance characteristics of basic motor model. The acquired analytical model is applied in optimization software that uses genetic algorithms (GA) as an optimization method. Optimized motor model with increased torque is derived by varying three motor parameters in GA program: winding turns ratio, average air gap flux density and motor stack length. Increase of torque has been achieved for nominal operation but also at motor starting. Accuracy of the derived models is verified by Simulink. The acquired values of several motor parameters from transient characteristics of Simulink models are compared with the corresponding values obtained from analytical models of both motors, basic and optimized. Numerical analysis, based on finite element method (FEM), is also performed for both motor models. As a result of the FEM analysis, magnetic flux density in motor cross-section is calculated and adequate conclusions are derived in relation to core saturation and air gap flux density in both motor models.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals DESIGN OF A SINGLE-PHASE RADIAL FLUX PERMANENT MAGNET GENERATOR WITH VARIATION OF THE STATOR DIAMETER

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Hari Prasetijo ◽  
Winasis Winasis ◽  
Priswanto Priswanto ◽  
Dadan Hermawan
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Single Phase ◽  
Air Gap ◽  
Wire Diameter ◽  
Terminal Phase ◽  
Magnetic Flux Density ◽  
Phase Voltage ◽  
Radial Flux

This study aims to observe the influence of the changing stator dimension on the air gap magnetic flux density (Bg) in the design of a single-phase radial flux permanent magnet generator (RFPMG). The changes in stator dimension were carried out by using three different wire diameters as stator wire, namely, AWG 14 (d = 1.63 mm), AWG 15 (d = 1.45 mm) and AWG 16 (d = 1.29 mm). The dimension of the width of the stator teeth (Wts) was fixed such that a larger stator wire diameter will require a larger stator outside diameter (Dso). By fixing the dimensions of the rotor, permanent magnet, air gap (lg) and stator inner diameter, the magnitude of the magnetic flux density in the air gap (Bg) can be determined. This flux density was used to calculate the phase back electromotive force (Eph). The terminal phase voltage (V∅) was determined after calculating the stator wire impedance (Z) with a constant current of 3.63 A. The study method was conducted by determining the design parameters, calculating the design variables, designing the generator dimensions using AutoCad and determining the magnetic flux density using FEMM simulation.  The results show that the magnetic flux density in the air gap and the phase back emf Eph slightly decrease with increasing stator dimension because of increasing reluctance. However, the voltage drop is more dominant when the stator coil wire diameter is smaller. Thus, a larger diameter of the stator wire would allow terminal phase voltage (V∅) to become slightly larger. With a stator wire diameter of 1.29, 1.45 and 1.63 mm, the impedance values of the stator wire (Z) were 9.52746, 9.23581 and 9.06421 Ω and the terminal phase voltages (V∅) were 220.73, 221.57 and 222.80 V, respectively. Increasing the power capacity (S) in the RFPMG design by increasing the diameter (d) of the stator wire will cause a significant increase in the percentage of the stator maximum current carrying capacity wire but the decrease in stator wire impedance is not significant. Thus, it will reduce the phase terminal voltage (V∅) from its nominal value.

Modal-frequency spectrum of magnetic flux density in air gap of permanent magnet motor

2014 ◽  
Vol 63 (1) ◽  
pp. 29-46
Author(s):  
Pawel Witczak ◽  
Witold Kubiak ◽  
Marcin Lefik ◽  
Jacek Szulakowski
Keyword(s):  
Permanent Magnet ◽  
Flux Density ◽  
Frequency Spectrum ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Permanent Magnet Motors ◽  
Modal Frequency ◽  
Time Stepping ◽  
Sinusoidal Shape ◽  
Flux Density Distribution

Abstract The classic relationships concerning the harmonic content in the air gap field of three-phase machines are presented in form of series of rotating waves. The same approach is applied to modeling of permanent magnet motors with fractional phase windings. All main reasons of non-sinusoidal shape of flux density distribution, namely, magnets’ shape and their placement, slotting, magnetic saturation and eccentricity are also related to their counterparts in modal-frequency spectrum. The Fourier 2D spectrum of time-stepping finite element solution is confronted with results of measurements, with special attention paid to accuracy of both methods

Magnetic Force Characteristics and Structure of a Novel Radial Hybrid Magnetic Bearing

2012 ◽  
Vol 150 ◽  
pp. 69-74
Author(s):  
Jun Hui Chen ◽  
Feng Yu Yang ◽  
Chao Rui Nie ◽  
Jun Yang ◽  
Peng Yan Wan
Keyword(s):  
Flux Density ◽  
Equilibrium Position ◽  
Magnetic Force ◽  
Magnetic Bearing ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Initial Current ◽  
Virtual Displacement ◽  
Self Stabilization ◽  
Radial Magnetic Bearing

There are some problems in the permanent magnetic circuit of the current permanent magnet biased magnetic bearings, such as small magnetic force, low magnetic flux density and lack of self-stabilization. To solve this problem, a new hybrid radial magnetic bearing structure has been proposed. The nonlinear model and linearization equation of the new hybrid radial magnetic bearing capacity has been established by current molecular method and virtual displacement theorem. It is found that the permanent magnetic bearing can achieve self-stabilization in the radial degrees of freedom and can reduce the total displacement of negative stiffness. The results show that the air gap flux density is greatly improved by the new hybrid magnetic bearing with Halbach array structure. Current stiffness and displacement rigidity is closely related to initial current and initial gap of the equilibrium position. Near the equilibrium position, current stiffness and displacement rigidity are linear relationship. With the increase of air gap, it remains a good linearity. While with the decrease of air gap, it presents nonlinear characteristics..

Control for Optimized Air-Gap Magnetic Field of Five-Phase Induction Motor through Dual-Plane Asynchronous Rotation Transformation

2013 ◽  
Vol 347-350 ◽  
pp. 486-490
Author(s):  
Mu Yi Yin ◽  
Ling Zhang ◽  
Peng Zhu ◽  
Fei Guan
Keyword(s):  
Magnetic Field ◽  
Induction Motor ◽  
Flux Density ◽  
Mechanical Load ◽  
Air Gap ◽  
Linear Functions ◽  
Magnetic Flux Density ◽  
Third Harmonic ◽  
The Third ◽  
Air Gap Magnetic Field

This paper presents a control scheme with an optimized air-gap magnetic field for five-phase induction motor, the control objective is to generate a quasi-square magnetic flux density by the control of excitation and torque currents in the two planes. In this paper, the decoupling vector control model of five-phase induction motor in d1-q1-d3-q3 coordinate system is analyzed, and the direct and quadrature current components in the third harmonic plane as non-linear functions of the fundamental are built, which guarantee the air-gap magnetic to be a constant quasi-square waveform irrespective of the mechanical load, and then the third harmonic current injected method for improved air-gap magnetic field is proposed. Finally, the simulations by Matlab/Simulink and experiments are implanted on a 5.5 kW, five-phase concentrated full-pitch windings induction motor. The results indicate that the proposed method can satisfy the requirement of a quasi-square air-gap flux density, and the air-gap magnetic field gets improved.

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