Wyniki wyszukiwania - BazTech

1

Rotating field in induction motor under consideration of anisotropy and cutting strains of steel sheets

Zagradisnik I., Slemnik B.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

521-525

EN

The rotating magnetic field in a symmetrical induction machine supplied with a sine-shaped and balanced system shows an asymmetrical shape if the magnetic medium is anisotropic. The shape of the air gap magnetic flux distribution is repeated twice per one revolution of the rotating field in a two-pole machine. The harmonic analyses show that all components rotate with variable magnitudes and non-uniform speeds. The variations are greater if the order of the component is higher. Only odd harmonics occur. Due to the spatial dependence of reluctance and the electric voltage balance in an induction machine, the magnetizing current also shows a spatial dependence.

2

Motional finite element simulation of magnetic brakes and solid rotor induction machines

De Gersem H., Hameyer K.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

389-397

EN

The torques of a magnetic brake and a solid rotor induction machine, fed by sinusoidal voltage sources, are simulated by a motional finite element method. Oscillatory solutions occurring for motional models with elevated velocities, are prevented by adaptive mesh refinement relying upon intermediate solutions stabilised by upwinded finite element test functions. A relaxed successive approximation deals with the non-linear material properties. The connections of the conductors and windings within the finite element model to external loads, impedances and supplies are represented by an electric circuit and added to the system of equations. The technical examples indicate the advantages of the motional formulation.

3

Interaction of saturation of magnetic circuits for the main and leakage fluxes in induction machines

Sobczyk T. J.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

475-481

EN

The paper presents a model of induction machines, in which saturation for both the main and leakage fluxes of individual windings is represented. The model operates with the real winding currents what gives a chance to model saturation of leakage magnetic circuits separately for each winding. The saturation of the main magnetic circuit is modelled by introducing a magnetising current denned analytically by all machine currents. Such a model allows to study the interaction of saturation of separately treated magnetic circuits of the main and leakage fluxes. Remarkable results of simulations are shown in the paper.

4

Flux-weakening and output power capability estimation of interior permanent magnet synchronous motor in variable speed drive applications

Stumberger B., Hamler A., Jesenik M., Gorican V., Trlep M.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

489-494

EN

Flux-weakening and output power capability estimation of the four-pole interior permanent magnet synchronous motor (IPMSM) determined from the finite element method (FEM) analysis of magnetic conditions is presented. The influence of the iron loss on the output power capability (OPC) and the constant-power speed range (CPSR) of the tested IPMSM is included in the analysis by the posterior iron loss calculation. Results of the calculations are partially verified by the measurements.

5

Electromagnetic field analysis of 2D-3D structure of switched reluctance motors (disc-type)

Wiak S., Drzymała P., Welfle H.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

505-513

EN

In the paper comparative studies of 2D-3D disc-type Switched Reluctance Motor (SRM) structures are performed. The calculation of magnetic field distributions and the static torque characteristics have been computed by means of Finite Element Method (FEM) for 2D and 3D motor structures. It has been emphasized that the calculations of the model structure (thanks to axial symmetry) have been done for a half of the volume while the boundary conditions are predefined. 3D structure of the model motor is built up, then the mesh is generated for number of elements exceeding 100 000. The results of 3D calculations are presented in the form of the static torque characteristics and magnetic flux curves versus rotor angular positions and current densities in the stator winding as well. Disc-type SR motors thanks to their specific structures are commonly used in automotive system, servo-drives, etc. The motor structure consists of the stator core toroidally shaped in which slots are placed on both sides of the active surface; moreover stator windings are wounded as Gramma type (made of identical coils surrounding the stator core). SRM are proposed to be mounted at the wheel of gearless electric vehicles (small cars, wheelchair, scooters, etc.).

6

Calculation of electromagnetic field in a disk-type induction motor using a 3-D reluctance network method

Ciosk K.

Journal of Technical Physics

|

2002

|

Vol. 43, no 4

383-387

EN

The paper presents an analysis of the magnetic field in a disk-type induction motor with double-sided stator and twin rotors. The magnetic flux density was found in a 3-D space using the reluctance network method (RNM). The results were compared with the measurements carried out on the real object.