RU2668990C1 - High-frequency choke - Google Patents

Abstract

FIELD: electrical equipment.SUBSTANCE: invention relates to electrical equipment. Throttle is made toroidal with a sawtooth winding on the frame. Toroidal core is made of separate layers of soft magnetic material with the greatest maximum induction and a narrow hysteresis loop with the same minimum thickness of each layer, embedded in cups, isolated from each other and from the winding on the frame. Over the air gaps of each layer, magnetically conductive shunts of a soft magnetic material with a maximum initial magnetic permeability are installed.EFFECT: technical result consists in increasing the load currents with increasing frequency of the supply voltage and reducing inductive and active losses.1 cl, 3 dwg

Description

The invention relates to electrical engineering, to the section "Winding products".

Known chokes in circuits with large load currents, which are widely used. However, their disadvantage is malfunctions when the nominal frequency of the supply voltage is exceeded.

The purpose of the invention: to achieve reliable operation of the inductor with a multiple increase compared to the nominal frequency of the supply voltage.

The inventive objective is achieved by reducing the magnitude of the leakage inductance and active losses in the inductor due to the use in its design:

- sawtooth winding on the frame in accordance with the prototype "Inductor" (patent RU 2006084 C1);

- a core in the form of a toroidal multilayer magnetic circuit, consisting of separate layers with the same minimum thickness of each layer of soft magnetic material with the largest maximum induction and a narrow hysteresis loop;

- magnetic shunts above the air gaps of each layer of magnetically soft material with a maximum initial magnetic permeability.

Known chokes with a single toroidal core without magnetic shunts above the gaps existing in it cannot serve for this purpose due to large active losses and dissipation inductance already in the choke core itself.

The same chokes cannot serve for this purpose if:

- on the throttle frame, ordinary ordinary winding (due to the large scattering inductance and large capacitive connections between the winding turns);

- the magnetic system in the inductor is open (due to the large scattering inductance in it);

- the magnetic systems are closed, but they do not coincide along the perimeter of the position of the beginning and end of the winding (due to the large scattering inductance in the winding);

- in accordance with the prototype, the sawtooth winding on a frame with a single toroidal core (due to large losses in the core, see above).

In FIG. 1 shows the proposed high-frequency inductor and its section. In FIG. 2 - development of the sawtooth part of the winding with 9 turns in it, in two rounds. In FIG. 3 same with 18 turns, in eleven rounds.

The design of the inductor inside the frame can be performed with any number of layers in the magnetic circuit, with the same minimum thickness of each layer, with isolation from the winding on the frame and from each other. The number of air gaps in each layer is the same and can be any. As a layer, any twisted core that can be taken can be taken; the above technical requirements, either a flat core or a magnetically conductive wire, all with the same technical specifications. The invention does not change from this.

The design of the throttle contains: a frame of two halves 1 with a sawtooth winding on it, toroidal cups 2 of insulating material, gaskets 3 from the pressboard (electric cardboard) on top of each cup, insulating washers 4 between adjacent cups, gasket (lock) 5 from the pressboard at the junction between the upper and lower half of the frame, the magnetically conductive layer 6 inside the cups, the magnetically conductive shunts 7 inside the windows above the air gaps in the layers, thin insulation 8 between the shunts and the layers of the magnetic circuits, clamping inserts 9 of PCB in the windows above the shu ntami, glass (screen) 10, base 11, cover (plug) 12.

Structurally, the even number of cups in the frame is even in the upper and lower half of the frame. All layers in the cups are divided into pairs, the upper and lower layers in each pair.

When laying cups assembled inside the frame to maintain a fixed order of relative position of the air gaps in each layer with respect to the gaps in the other layers, vertical protrusions are made on the outer walls of the cups at diametrically opposite edges, which, when the cups are inserted with the bottom inside each half of the frame, fall into grooves made at the same level inside the walls of the halves of the frame. Each cup is marked with one of the marks: BB, BH, HB, HH, where B and H indicate that the cup belongs to one of the half of the frame: the top with the mark “B” or the bottom with the mark “H”. The index “c” means that the cup should be inside the frame above the cup with the index “n”.

To create the selected position of the air gaps in the layers in each of the cups, marking was carried out in the form of marking on the bottom of the cups and above - on the faces of their walls in the form of notches:

- the initial air gap in the cups BB and HB at the level of the protrusion of the cup (on the right in Fig. 1), in the projection of the frame 13 coinciding with the protrusion, coming out from below through the slot in the cup to the level of the beginning and end of the winding (N.K.) on the frame ;

- the remaining air gaps in cups BB and HB, starting from the risks of the initial air gap, with a uniform application at intervals determined by the number of gaps in the layer, when circumambulating around the perimeter counterclockwise for cups BB and clockwise for cups HB;

- air gaps in cups HH and HH with a shift of half the interval in relation to the risks in cups HV and Hv when circumvented around the perimeter counterclockwise for cups HH and clockwise for cups HH;

- diametric notches that define the boundaries of the windows inside the cups, with a retreat of two and a half millimeters (2.5 mm) in opposite directions from the marks of air gaps.

Subsequent operations:

- cutting windows inside the cups with a slight scuffing of their walls and at the same level - in the gaskets 3 laid in the cups;

- the implementation in the intervals between the windows in the bottoms of the cups and in the parts of the gaskets 3 thin through holes;

- laying a magnetic layer inside each cup without clamping from the side of its walls;

- fixing the layers in the cups with insulating adhesive through the holes in the cups and in the parts of the gaskets 3;

- spraying insulation in the windows from the bottom of the cups and from above, from the side of the parts of the gaskets 3, approximately the size of the air gap;

- the operation to create air gaps in the layers using notches on the faces of the walls of the cups;

- laying in the windows above and below the layers in the cups of magnetic conductive strips (shunts) with a thickness of tenths of a millimeter while pressing them together with clamping inserts 9. Before laying the strips on each strip (shunt) there should be a “MARK” of the direction of the residual magnetization field (for a twisted core -the workpiece, it coincides with the direction of winding), transferred from the workpiece, which should coincide when laying with the direction of magnetic flux in the layers of the magnetic circuit. When cutting strips, burrs are removed, strips cut from a twisted core tape are placed in the windows with the curved side down;

- after placing the assembled cups 2 together with insulating washers 4 between them in their places in the halves of the carcass, the halves of the carcass are articulated using a gasket 5 having the same protrusions and at the same level as the cups with a thickness that allows entry in the grooves of the upper and lower half of the frame;

- placing the frame with the winding wound on it in a glass 10, which is fastened to the base 11 through the mounting holes 14;

- filling the entire structure with a compound through the open cap 12. If there is a small air gap 15 inside the glass on top of the frame, the filling is complete.

A choke with 9 turns of a single-layer sawtooth winding with two rounds of winding (such a choke has the highest inductance among options with a small number of turns of a sawtooth winding). A full revolution of the coil on the frame is 80 degrees. Four layers of the magnetic circuit. In each layer there are three air gaps from 10 to 20 microns in size.

To create the selected position of the air gaps in the layers produced along the lines of turns in the winding, risk marking is performed inside the cups. Initially, the extreme points of the marks were obtained after winding the turns of the winding on the frame with a trace of the winding on the frame. Further, each cup is inserted in turn with the bottom inward in its half of the frame with fixing in it and making thin through holes in the frame and bottom of the cup. Drilling is performed from above from both edges of the frame along the lines of the halves of the selected turns at certain points obtained by deviating from the edges by the thickness of the frame wall and the cup wall. The sequence and type of processing in the cups up to the complete assembly of the throttle - see above. Air clearance:

- for the layer in the cup BB - at the location of the upper half of the turns 1, 4, 7;

- for the layer in the cup Nn - at the location of the lower half of the turns 1, 4, 7;

- for the layer in the cup Vn - at the location of the upper half of the turns 3, 6, 9;

- for the layer in the HB cup - at the location of the lower half of turns 3, 6, 9.

The coils for placing the gaps in the layers are selected in such a way that with this design of fixing the cups in the frame and with a certain order of laying them in the frame, a fixed uniform distribution of the gaps in each layer is obtained with a shift by half of the obtained interval with respect to the air gaps in the adjacent layers .

Magnetic conductive shunts over air gaps with a minimum insulation thickness between them and the layers of the magnetic circuit with oblique separation of the layer can maintain the optimal magnetic permeability of the layers at an optimum level and bypass excessive scattering fluxes in the layers.

Inductor with 18 turns of a single-layer sawtooth winding in eleven rounds of winding.

Since the distance between adjacent turns in the end part of the frame should be kept optimal (due to the stringency of requirements in the presence of inter-turn capacitance), the size of the frame along the diameter of an 18-turn throttle should be twice as large as that of a 9-turn throttle.

A full revolution of the coil on the frame is 220 degrees. Eight layers of the magnetic circuit. In each layer there are three air gaps with a size of 10 to 20 microns. The performance of the air gaps is identical - according to the risks in the cups held along the diametrical lines:

- for the upper layers in the cups BB and HB with an interval of 120 °, the initial clearance is at risk at the place of the protrusion of the cup at the level of N. K. (in Fig. 1 - to the right, see below);

- for the lower layers in the cups HV and HN - for risks with a shift of 60 ° relative to the risks in the cups HV and HB.

The marking of the grooves when going around the perimeter for cups BB and BH is counterclockwise, for cups HB and Hn, clockwise.

For further processing in cups see above.

All types of materials and sizes given in the text are close to the most constructively acceptable and can be specified during assembly and debugging of the throttle.

A significant difference between the design of the proposed inductor from the design of all standard inductors outside and inside the inductor frame allows us to expect reliable operation with a multiple increase in the nominal frequency of the supply voltage.

Claims (1)

A high-frequency toroidal inductor with a sawtooth winding on the frame, with a magnetic circuit inside the frame case, consisting of several layers with the same minimum layer thickness, with the same number of air gaps in each layer, with the layers placed in cups isolated from each other and from the inductor winding, with fixing the position of the air gaps in the layer of each cup with the help of the presence in the cups of vertical protrusions in diametrically opposite sides of the walls of the cups included in the internal grooves of the walls of the frame, one and of which at the level of the position of the beginning and end of the winding on the frame, with an even number of layers in the magnetic circuit when they are divided into pairs, the upper and lower layers in each pair, after each layer is fixed in the cup, air gaps in each upper layer with the same interval along the perimeter, with a shift in the half-interval with respect to the position of the air gaps in the lower layer adjacent to it, at the level of the location of the half turns above and below the frame, specially selected to obtain the above-mentioned intervals between the floors zheniyami air gaps in the upper and lower layers of the magnetic circuit, or at an angle to it, with the initial air gap in the upper layers of the magnetic circuit around the perimeter at the level of the position of the beginning and end of the winding at the exit of the frame, with the presence of windows above and below in the cups above the air gaps in the layers of the magnetic circuit, with placement in the windows with the clamp of magnetic shunts with thin insulation under them from the layers of the magnetic circuit.

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