0000000000147464
AUTHOR
Marian Lukaniszyn
APPLICATION OF 3‐D FINITE DIFFERENCE METHOD FOR INDUCTANCE CALCULATION OF AIR‐CORE COILS SYSTEM
The paper deals with the inductance calculation of air‐core coils system by means of 3‐D analysis of magnetic field of the coils with rectangular cross‐section. The possibility of mutual and self‐inductance calculation is presented. For magnetic field calculation, the Finite Difference Method with application of fast calculating procedures was applied. The method of calculation has been verified by experiments. The obtained difference between calculating and measurement results is equal to a few percent. The computer program is usefull especially for asymmetrical configuration of the coils.
A study on the influence of permanent magnet dimensions and stator core structures on the torque of the disc-type brushless DC motor
This paper presents a three-dimensional analysis of the magnetic field distribution for a disc-type, double-sided, permanent magnet, brushless dc motor with a toroidal stator core. Calculations are carried out using the OPERA (3D) package with the TOSCA module. The electromagnetic torque is determined from the Maxwell stress tensor. For comparison, various permanent magnet dimensions and slotless vs. quasi-slotted stator cores are analysed, with an iron powder-resin composite effectively used to imitate the slotted core. The torque ripple is shown to be effectively reduced by appropriate permanent magnet dimensions. The simulation results are in good agreement with experimental data obtaine…
Constrained minimum variance control of nonsquare LTI MIMO systems
Constrained minimum variance control is offered for nonsquare LTI MIMO systems. A constrained control design takes advantage of the so-called control zeros. The new control strategy is compared with familiar generalized minimum variance control and possible application areas of the two are discussed.
2D harmonic analysis of the cogging torque in synchronous permanent magnet machines
Presents an approach to determine sources of cogging torque harmonics in permanent magnet electrical machines on the basis of variations of air‐gap magnetic flux density with time and space. The magnetic flux density is determined from the two‐dimensional (2D) finite element model and decomposed into the double Fourier series through the 2D fast Fourier transform (FFT). The real trigonometric form of the Fourier series is used for the purpose to identify those space and time harmonics of magnetic flux density whose involvement in the cogging torque is the greatest relative contribution. Carries out calculations for a symmetric permanent magnet brushless machine for several rotor eccentricit…
Electromechanical properties of a disc‐type salient‐pole brushless DC motor with different pole numbers
A brushless, permanent magnet, three‐phase disc‐type salient‐pole DC motor with co‐axial flux in the stator is considered. Electromechanical properties of a basic eight‐pole motor are compared with those for a 16‐pole one of the same volume, in order to contrast the two potential candidates for variable‐speed, low‐cost drives. As a basis of the comparative analysis, 3D FEM magnetic field modelling and circuit analysis considering an electronic commutator are employed. Increasing the number of poles results in unfavourable raising in the switching frequency. The eight‐pole motor construction has been shown in simulations to have higher efficiency and lower power losses than its 16‐pole count…
Field‐circuit analysis of construction modifications of a torus‐type PMDC motor
This paper presents the field‐circuit analysis of a disc‐type torus DC motor with permanent magnets. Calculations of the magnetic field are carried out using the finite element method (FEM) in the 3D space. The integral quantities like the ripple‐cogging torque, back electromotive force, flux linkage, self and mutual inductances of the winding are analyzed. The electromagnetic torque is comparatively determined from the Maxwell stress tensor and co‐energy methods. Based on the 3D magnetic field calculations, the lumped‐parameter model of the tested motor is constructed, taking into account an electronic power converter as well. For comparison, various permanent magnet widths and teeth thick…
A disc-type motor with co-axial flux in the stator; - influence of magnetic circuit parameters on the torque
This paper presents a three-dimensional analysis of the magnetic field distribution for a three-phase, disc-type, permanent-magnet, brushless DC motor with co-axial flux in the stator. Calculations are carried out using the 3-D finite element method (FEM). The electromagnetic torque is determined from the Maxwell stress tensor. For comparison, various dimensions of permanent magnets, pole shoes and air gap are analysed. It is shown that the ripple-cogging torque can be effectively reduced by an appropriate permanent magnet width and air-gap length. The simulation results are in good agreement with experimental data obtained from the prototype motor.
Optimization of Permanent Magnet Shape for Minimum Cogging Torque Using a Genetic Algorithm
The paper presents an approach to minimization of the cogging torque in permanent magnet (PM) machines using surface-mounted magnets with discrete skew angle. For the purpose of determining the proper arrangement of PM-pole slices, an optimization procedure based on a genetic algorithm is applied. The torque and objective function are determined from a simplified model for torque calculation only partially supported by three-dimensional (3-D) field solution. The results are validated against the 3-D finite-element model as well as experimental data obtained from a prototype machine. A new outer-rotor brushless dc motor motor for an electric fan is considered as a sample model.
The reduction of fire and explosion risks in a cuboidal tank making use of a system of vertical grounding rods
The paper presents calculation results of the electric field in a cuboidal tank provided with a system of vertical grounding rods.