RU217081U1 - TRACTION ELECTRIC MACHINE - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used in traction electric machines with open slots for wedge fastening of stator and rotor windings, protecting windings from mechanical damage and as a means of reducing their thermal heating. Traction electric machine contains stator or rotor windings placed in open slots with wedge fastening. Groove wedges and intragroove gaskets are made of solid metal non-magnetic materials. EFFECT: reduction of thermal heating of the windings, reduction in the number of thermal breakdowns of the insulation of the windings, extension of the service life of the windings. 1 ill.

Description

The utility model relates to the field of traction electric machine building and can be used in traction electric machines (TEM) with open-type slots for wedge fastening of stator and rotor windings, protection of windings from mechanical damage and as a means of reducing their thermal heating.

The design currently used in traction electric machines is known with the fastening of windings in open-type grooves with wedges made of non-magnetic dielectric materials, mainly fiberglass (Shcherbakov V.G. and others. Traction electric machines. M .: FGBOU "Educational and Methodological Center for Education on railway transport”, 2016. - 641 p.). To reduce the likelihood of mechanical damage to the insulating coating of the windings during their laying under the wedges and at the bottom of the grooves, insulating gaskets made of dielectric mica-containing materials are laid.

The disadvantages of the existing design are:

low thermal conductivity of dielectric wedges and wedge gaskets with simultaneously high values of their specific heat capacity. Because of this, the wedge fastening area has a high thermal resistance to heat transfer processes and blocks the exit of heat flows from the intra-groove space heated by the conductors. In applied thermal calculations of a traction electric machine, the power of the heat transfer flow through the wedge fastening is assumed to be zero;

low volumetric electrical conductivity of dielectric wedges and intra-groove gaskets prevents the occurrence of eddy currents in them with a damping effect in relation to mechanical vibrations from tooth harmonics of the magnetic flux and magnetic conductivities of slot leakage flows involved in the formation of a reactive electromotive force in a collector-type traction electric machine;

low surface electrical conductivity of dielectric wedges and wedge gaskets contributes to the uneven distribution of potentials in the insulating coatings of the windings along the longitudinal axis of the machine, creating increased field strength gradients in the areas where the windings exit the slot;

the composite design of the wedges complicates the assembly technology of the machine.

The closest analogue of the proposed utility model is the rotor of an electric machine with slotted windings by a set (from two or more) of copper non-magnetic slotted wedges forming a longitudinal electrical circuit with high electrical conductivity used as a damper winding (Titov V.V. and other Turbogenerators: Calculation and design, L.: Energiya, 1967. - 895 p.).

The disadvantage of this design is the composite nature of the slot wedges, complicating the assembly technology of the machine. In addition, this design has become widespread only in the production of turbogenerators, but has not affected the class of traction electric machines.

The technical objectives of the claimed utility model are:

increasing the thermal stability of traction electric machines due to the high thermal conductivity of slot wedges and gaskets;

reduction of mechanical and switching loads of TEM during damping of magnetic fluxes of slot leakage due to the high electrical conductivity of slot wedges and gaskets;

reduction of gradients of the electric field strength in the areas of the exit of the windings from the groove due to the high surface electrical conductivity of the wedges and wedge gaskets;

simplification of the assembly technology of traction electric machines through the use of an all-metal construction of slot wedges.

The technical result obtained from the claimed utility model is to reduce the thermal heating of the windings, reduce the number of thermal breakdowns of the winding insulation and extend the life of the windings through the use of metal non-magnetic wedges and gaskets with high thermal conductivity.

To achieve the specified technical result in a traction electric machine containing stator or rotor windings placed in open-type slots with wedge fastening, according to the utility model, slot wedges and intra-groove gaskets are made of solid metal non-magnetic materials.

The essence of the utility model is illustrated by a figure.

In FIG. shows a cross-section of the proposed design of the groove of a traction electric machine, including copper conductors of winding 1 and high-voltage insulation 2. Groove wedge 3, gaskets 4 installed under the wedge 3, gaskets 5 installed between the upper and lower sections of the windings and gaskets 6 installed at the bottom of the groove , made of non-ferrous metals or alloys based on them.

The traction electric machine contains windings 1 located in the open slots of the stator or rotor and fixed with all-metal non-magnetic wedges 3 made of non-ferrous metals or alloys based on them. Protection of insulating coatings of windings 1 with high-voltage insulation 2 from mechanical damage in contact with laminated elements of the magnetic circuit and slot wedges 3 is carried out by gaskets 4, 5, 6 in the form of tapes, the material of which is similar to the material of slot wedges 3. The geometric shape and dimensions of slot wedges and gaskets 4 , 5, 6 are identical to the existing samples of the current series of traction electric machines.

It is proposed to replace traditional dielectric materials used in traction electric machines in the manufacture of slot wedges 3 and gaskets with an electrically conductive non-magnetic material made of non-ferrous metals or alloys based on them.

The proposed replacement of materials does not contradict the main functional purpose of the slot wedges 3 and gaskets 4, 5, 6 for mechanical fastening and mechanical protection of the windings, since, in terms of mechanical strength, metals are much superior to the dielectric materials and compositions used in modern traction electric machines.

As a result, the high heat-conducting properties of the slot wedge 3 and wedge gaskets 4, 5, 6, made of solid metal non-magnetic materials, provide an additional channel for the exit of heat flows from the intra-groove space when the winding conductors are heated.

Slot wedges 3 and gaskets 4, 5, 6 proposed for use, made of solid non-ferrous metals or alloys based on them, in terms of their magnetic properties, belong to the class of para- and diamagnets, which excludes their distorting effect on the distribution of the main magnetic flux in the air gap of the machine , thereby ensuring the invariance of the structural dimensions of the magnetic circuit, the stability of the operating parameters and characteristics of the modernized traction electric machines.

The high electrical conductivity of the materials proposed for replacement creates longitudinal conductive circuits inside the slot volume, which act as damper windings, which favorably reduce the levels of rotor vibration loads, reactive electromotive force in collector-type machines, and electric field strength gradients in the areas where the windings exit the slot.

The all-metal design of the slot wedges contributes to improving the manufacturability of the production of traction electric machines.

Claims (1)

Traction electric machine containing stator or rotor windings placed in open-type slots with wedge fastening, characterized in that the slot wedges and intra-groove gaskets are made of solid metal non-magnetic materials.

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