Research on a permanent magnet passively compensated pulsed alternator with ultra low mutual inductance research on a permanent magnet passively compensated pulsed alternator with ultra low mutual inductance
In this investigation, a permanent magnet passively compensated pulsed alternator (PMPCPA) with ultra low mutual inductance has been designed to provide an electrical pulse with the large power for the load in the shorter period. The electric excitation is replaced by the permanent magnet excitation, the passively compensated mode is adopted, and two-phase symmetrical windings with an electric angle difference of 90 degrees are respectively placed in the stator slots with both deep and shallow specifications to reduce the mutual inductance between the windings. On the basis of design scheme, the inductance of armature winding of alternator is calculated. Both noumenon and short circuit discharge models for the PMPCPA are established to perform the simulation, and the mutual inductance of PMPCPA is measured. The simulated and experimental results show that the present alternator can meet the design requirements, and the effectiveness of method for reducing the mutual inductance is verified.
Electromagnetic Analysis of a Permanent Magnet Compulsator (PMCPA)
The eddy current distribution in the shield of a new type CPA is discussed. In this new type CPA, permanent magnet is used to produce excitation field. Because of the permanent magnet, the working mode of this type CPA is different from the conventional CPA that using electric excitation. Therefore the discharge process and the action of the shield should be analyzed to design the parameters of the CPA. By making some assumptions, the problem of the electromagnetic field distribution can be simplified and an analytical solution of the two-dimensional diffusion equations can be obtained. The transient eddy current distribution in the shield and the forces on the armature during the discharge are discussed. Finite element method (FEM) is used and the results show that the conclusions from the analytical solution are basically correct and can be used for preparing and optimizing design data about later passive compulsators
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).