SU517112A1 - Electric direct current machine - Google Patents

Description

one

The invention relates to electrical engineering and in particular to collector electric machines and a constant current with superconducting field windings.

The known electric machines of this type contain an excitation winding consisting of superconducting coils placed in a stator cryostat and a rotor with a core and a collector winding located on it.

The high magnitude of the induction of the magnetic field in the winding zone of the core, created by the superconducting coils of the excitation winding, makes it possible to refuse the use of ferromagnetic materials in the core structure of an electric machine. In this case, the spatial distribution of the magnetic field of the superconducting excitation winding in the core winding zone is such that both radial and tangential components of the magnetic field occur in the region of the switching sections of the core winding. Both component fields negatively affect the switching characteristics of the machine.

To improve the commutation of the electric machine by reducing the winding of the electromotive force core induced in the switching sections caused by the magnetic fields of the scattering of superconducting coils.

The excitation windings in the proposed electric machine in the cryostat between the coils of the excitation winding in the axial direction there are strips of superconducting material, and on the inner shell of the cryostat beneath these superconducting strips in the same direction are rods of ferromagnetic material.

The drawing shows a cross-section of the described DC electric machine, where 1 is the superconducting coil of the excitation winding; 2 - outer shell of the cryostat; 3 - inner shell of the cryostat; 4 - rotor; 5 - commuting sections of the winding core; 6 - strips of superconducting material; 7 - rods of ferromagnetic material.

The superconducting coils 1 of the excitation winding create in the zone of the switched sections 5 a magnetic dissipation field which induces an electromotive rotational force in the sections which worsens the switching of the machine. Superconducting strips 6 located

between the coils, they act as shields, which, due to the demagnetizing field created by the shielding currents induced in them by the fields of the excitation winding, reduce the radial component of the magnetic field in the zone of the switching sections 5 core and thereby reduce the value of the EMF of rotation induced in these sections.

The magnetic zero is aligned in the zone of the switching sections 5 in the tangential direction due to the ferromagnetic shielding rods 7 located in the immediate vicinity of the core of the electrical machine. The rods are axially located, for example, on the inner shell of the cryostat, and their width is equal to the width of the switching zone of the electric machine. It also reduces the EMF of rotation in the switching sections and improves the commutation of the DC collector machine with the superconducting field winding.

Claims (1)

Invention Formula An electric direct current machine comprising an excitation winding consisting of superconducting coils placed in a stator cryostat, including an inner and outer shell, and a rotor r located on it with a core and collector winding, characterized in that In order to improve operational reliability by improving switching, in a cryostat between the coils of the excitation winding in the axial direction are placed strips of superconducting material, and on the inner shell of the cryostat under these superconducting strips in the same direction are rods of ferromagnetic material.