Device for connecting power supply to sensor

Abstract

A device for connecting a power source (9) to an inductor (10), comprising at least three connecting plates (11-14, 20) made of conductive material, to which any number of capacitors (7) are electrically connected, the connecting plates allowing electrical connection between the power source and the inductor in a parallel, series or series-parallel configuration, characterized in that at least two of the connecting plates are bent substantially through 90°, each forming two substantially mutually perpendicular half-plates (31-38), each half-plate being electrically connected to a different connecting plate (11-14, 20).

Description

Technical Field

[0001] The present invention relates to an arrangement for mounting a capacitor for use in an oscillating circuit of an induction heating device. Background Art

[0002] The device for mounting capacitors in an oscillating circuit comprises a connection plate made of a conductive material (typically copper) on which the capacitors are mounted. Typically, a plurality of capacitors are mounted on the plate, the number of which depends on their specific capacitance, the desired total capacitance, and the electrical characteristics of the oscillating circuit (voltage, current, and frequency).

[0003] Current capacitor mounting arrangements typically provide Figure 1 In order to help understand the parallel connection board for series-parallel configuration (in-line configuration) based on this figure and the Figure 3 、 Figure 7 、 Figure 9 and Figure 11 The mounting principle is disproportionate and the gaps between the plates are greatly emphasized. In this figure, four connecting plates 1, 2, 3, 4 are arranged in parallel, with the two outer plates and the two central plates being arranged in the same plane. The arrangement thus comprises two insulating plates. In this example, and in this cross-sectional view, two capacitors 7 are attached to the first outer plate 1 and another capacitor 7 is attached to the second outer plate 4. The two central connecting plates 2, 3 are arranged between the two outer plates 1, 4. For example, they are made of Teflon. Fabricated insulating plates 5 and 6 are placed between the outer connecting plates and the central connecting plate. In a longitudinal view of the device (not shown), multiple capacitors are connected at the height of connecting plates 1 and 4, with the number of capacitors depending on the specifics of the installation. The capacitors include means for securing them to the connecting plates, such as threaded holes for mounting screws, and electrical connecting rods 8, such as threaded rods. The connecting plates include holes that conform to the capacitor connecting rods, allowing them to pass through. The diameter of the holes in the connecting plates is selected based on the diameter of the connecting rods, making them large enough to prevent current from passing between the capacitor rods and the plate to which they are attached, thereby ensuring electrical isolation. The length of the capacitor connecting rods is sufficient to allow connection to another connecting plate. In this example, the capacitors in outer plates 1 and 4 are electrically connected to central plates 2 and 3 using nuts. The outer plates include holes that conform to the capacitor connecting rods, allowing the nuts and keys used to secure them to pass through. A power supply 9 is electrically connected to plates 1 and 2, and an inductor 10 is electrically connected to plates 3 and 4. Figure 2 Shows the corresponding Figure 1 Electrical diagram for this example of a series-parallel configuration.

[0004] In this type of in-line configuration, the two outer plates 1 , 4 are separated by the presence of the central plates 2 , 3 and the electrically insulating plates 5 , 6 .

[0005] The disadvantages of this type of configuration are as follows:

[0006] • A large self-inductance is produced due to the large space between the two external connection plates (this self-inductance increases when the space between the plates increases).

[0007] This self-inductance generates electrical losses and thus reduces efficiency, and the magnetic field generated by the current flowing in the connection heats the connection plates, requiring greater cooling (electrical loss image).

[0008] • Operator access to various components for installation and maintenance is often complicated. Summary of the Invention

[0009] According to a first aspect of the present invention, a device for connecting a power source to an inductor is proposed, the device comprising at least three connecting plates made of a conductive material, and any number of capacitors being electrically connected to the at least three connecting plates, the connecting plates allowing electrical connection between the power source and the inductor in a parallel, series, or series-parallel configuration, characterized in that at least two of the connecting plates are bent substantially through 90°, each connecting plate forming two substantially mutually perpendicular half-plates, each half-plate being electrically connected to a different connecting plate.

[0010] According to one possibility, one of the three connection plates can be substantially straight and electrically connected to two different connection plates.

[0011] According to another possibility, the device may comprise four connecting plates bent substantially through 90°, each connecting plate forming two substantially mutually perpendicular halves, each half being electrically connected to a different connecting plate, the assembly having substantially the shape of a cross in cross section.

[0012] The two connecting halves of one and the same connecting plate can be separated from the two other connecting halves of another connecting plate by at least one plate made of insulating material and bent substantially through 90°.

[0013] Advantageously, the connecting plate may comprise cooling channels in which a cooling fluid circulates.

[0014] According to a second aspect of the present invention, an induction heating device is provided, comprising a power supply and an inductor, wherein the electrical connection between the power supply and the inductor is produced by at least one device according to the first aspect of the present invention or one or more modifications thereof.

[0015] The invention makes it possible to reduce the inductance in the connection to a negligible level and therefore reduce the magnetic field generated by the current circulating in the connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features and advantages of the present invention will become apparent from the following detailed description. For an understanding of the present invention, reference is made to the accompanying drawings, in which:

[0017] [ Figure 1 ] is a schematic cross-sectional view of an in-line configuration of connection plates for a series-parallel configuration of capacitors according to the prior art.

[0018] [ Figure 2 ] corresponds to Figure 1 Schematic diagram of the electrical block diagram of the series-parallel configuration.

[0019] [ Figure 3 ] is a schematic cross-sectional view of a cross-shaped configuration of connection plates for a series-parallel configuration of capacitors according to an embodiment of the present invention.

[0020] [ Figure 4 ] corresponds to Figure 3 Schematic diagram of the electrical block diagram of the series-parallel configuration.

[0021] [ Figure 5 ] is a schematic three-dimensional view from a first perspective of a cross-shaped configuration of connection plates for a series-parallel configuration of capacitors according to an embodiment of the present invention.

[0022] [ Figure 6 ] is based on the second perspective Figure 4 Schematic 3D view of the cruciform configuration.

[0023] [ Figure 7 ] is a schematic cross-sectional view of a cross-shaped configuration of connection plates for a parallel configuration of capacitors according to an embodiment of the present invention.

[0024] [ Figure 8 ] corresponds to Figure 7 Schematic diagram of the electrical block diagram of the parallel configuration.

[0025] [ Figure 9 ] is a schematic cross-sectional view of a cross-shaped configuration of connection plates for a series configuration of capacitors according to an embodiment of the present invention.

[0026] [ Figure 10 ] corresponds to Figure 9 Schematic diagram of the electrical block diagram of the parallel configuration.

[0027] [ Figure 11 ] is a schematic cross-sectional view of a T-shaped configuration of a connection plate for a series-parallel configuration of capacitors according to an embodiment of the present invention.

[0028] [ Figure 12 ] corresponds to Figure 11 Schematic diagram of the electrical block diagram of the configuration.

[0029] [ Figure 13 ] is based on Figure 11 Schematic cross-sectional view of an alternative embodiment of a T-shaped configuration of a connection plate, shown here in a series-parallel configuration.

[0030] [ Figure 14 ] is based on Figure 13 Schematic cross-sectional view of an alternative embodiment of a T-shaped configuration of connection plates, shown here in a parallel configuration.

[0031] [ Figure 15 ] is a longitudinal schematic diagram of an exemplary application of the present invention.

[0032] Since the embodiments described hereinafter are not restrictive in nature, variants of the invention comprising only a selection of the described features are particularly conceivable, provided that this selection of features is sufficient to confer a technical advantage or to distinguish the invention from the prior art. This selection comprises at least one preferred functional feature without structural details or with only a portion of the structural details, if this feature alone is sufficient to confer a technical advantage or to distinguish the invention from the prior art.

[0033] In the remainder of the specification, elements having the same structure or similar functions will be designated by the same reference numerals. DETAILED DESCRIPTION

[0034] Figure 3 The configuration of the connection plate for a series-parallel configuration according to an embodiment of the present invention is schematically shown in cross section. Figure 4 Its basic electrical diagram is similar to that shown in Figure 2 . As can be seen in this figure, the four connecting plates 11, 12, 13, 14 are bent at right angles, and the assembly essentially forms a cross in cross-section. Consequently, the connecting plates are separated only by the thickness of the insulating plates 15, 16, while no connecting plates are arranged between the outer plates. Consequently, the distance between two connecting plates is reduced to a strict minimum value related to the thickness of the insulating plates required to provide electrical insulation between the plates. Similarly, in a longitudinal view of the device (not shown), a plurality of capacitors are connected at the level of the connecting plates 11 and 12, the number of capacitors depending on the characteristics of the installation.

[0035] The advantages of this type of configuration are as follows:

[0036] Self-inductance is negligible due to optimal electrical compensation due to the reduced distance between the connecting plates,

[0037] This self-inductance produces very small electrical losses, resulting in very good efficiency.

[0038] The magnetic field generated by the current flowing in the connection is weak, resulting in little heating in the connection plates and therefore requiring little cooling.

[0039] Operators can easily access various components for installation and maintenance.

[0040] Optimal electrical balance.

[0041] Advantageously, the insulating plates 15, 16 are also bent at right angles, thereby preventing any risk that an arc would be generated in the centre of the cross due to the use of straight plates. Figure 3 As shown in , a bent insulation plate ensures perfect continuity of the insulation material in the center of the cross, whereas a straight plate would result in discontinuity of the insulation material at the intersection of the cross center, thereby creating a risk of leakage paths at points where the insulation material may be insufficient, i.e. at the junction of the two plates. In order to facilitate bending the insulation plate through 90°, it may be advantageous to use two plates of half thickness rather than a single plate which may be more difficult to bend. Thus, for example, two plates with a thickness of 1 mm may be used. The plate is replaced by a plate measuring 2 mm thick.

[0042] Figure 5 and Figure 6 Another example of a capacitor mounting device according to the invention with a cross-shaped connection plate in a series-parallel configuration is shown in longitudinal view from two different perspectives. In the three-dimensional representations of these figures, the size ratio of the components is Figure 1 and Figure 3 The dimensional proportions in are closer to reality. The assembly comprises a group of 8 capacitors. These capacitors are cooled by the flow of cooling water. For this purpose, each capacitor comprises a first connection 17 for the cooling water supply and a second connection 18 for the water outlet. The capacitors can all be connected in series to the same cooling water circuit, or they can be connected individually or in capacitor groups, each group being connected in parallel to the cooling circuit. The capacitor comprises a base made of an electrically conductive material, for example copper, by means of which the capacitor is fixed to a connecting plate by means of four screws 19. This thus creates electrical continuity between the connecting plate and the capacitor. The capacitor comprises a threaded rod 8 for electrical connection to another connecting plate to which the capacitor is fastened by means of a nut 21. The connecting plate comprises a cooling channel 22 in which the cooling water circulates. As in Figure 5 and Figure 6As can be seen in the figure, due to the limited heating of the connecting plates, the cooling channels cover only a part of the plate surface, i.e. the part where the current is strongest. The capacitors also contribute to the cooling of the connecting plates due to their water-cooled base. This channel 22 comprises a first connection 23 for the cooling water supply and a second connection 24 for the water outlet. The cooling channels 22 of the connecting plates can all be connected in series to the same cooling water circuit, or they can be connected in parallel. The cooling channels 22 of the connecting plates can be connected in series to the same cooling water circuit as the capacitors, or they can be connected to separate circuits. The connecting plates 11 and 12 are connected via two compensators 7 and via Figure 6 25 . Like the capacitor, this cooling ring is fixed to the plate 11 by means of four screws and also comprises a threaded rod 26 for electrical connection to the plate 12 to which the cooling ring is fastened by means of a nut 27. The electrical connection between the plates via the capacitor 7 or the connection of the ring 25 makes it easy to switch from a series-parallel type configuration to a series or parallel configuration.

[0043] Figure 7 Another embodiment of the invention is shown, which comprises four connecting plates mounted in a cross-shaped arrangement in parallel. In cross-section, this example comprises a capacitor 7 and two shunt rings 25. Again, the total number of capacitors and rings arranged longitudinally depends on the desired characteristics. Figure 8 The equivalent electrical diagram is shown in .

[0044] Figure 9 Another exemplary embodiment of the invention is shown, which comprises four connecting plates mounted in a cross-shaped arrangement in series. In this cross-sectional view, this example comprises two capacitors 7. As previously mentioned, the total number of capacitors and rings arranged longitudinally depends on the desired characteristics. Figure 10 The equivalent electrical diagram is shown in .

[0045] Figure 11 Another exemplary embodiment of the present invention is shown in a "T" shape comprising three connecting plates. In this arrangement, two of the connecting plates 11, 12 are bent 90°, while the third connecting plate 20 is straight. Figure 12 The equivalent electrical diagram of the series-parallel connection is shown in . It retains all the advantages of the invention, in particular due to the distance between each pair of connecting plates being reduced to the minimum possible.

[0046] exist Figure 13In the alternative embodiment shown in , the bent plates 11, 12 are formed in two parts 11a, 11b, 12a, 12b. They are fixed to each other by means of screws and nuts. This arrangement makes it easy to remove the series capacitors and thus convert to a parallel-only configuration. It is intended for applications that require flexibility during use (adaptation of the power supply-inductor-components), which may be necessary if very different components are heated. In order to convert from a series-parallel configuration to a parallel configuration, the components 11a, 12a are removed. As Figure 14 As shown in FIG, the components 11a, 12a are replaced by a connecting piece 28, which is fixed by means of screws and bolts.

[0047] The present invention is particularly suitable for the following situations:

[0048] Frequency: Intermediate frequency (from 15kHz to 2MHz)

[0049] Input voltage: Typically less than 1kV

[0050] Output voltage: up to 8kV (voltage increase)

[0051] Output current: up to 50kA

[0052] Electric power used for installation: >100kW

[0053] Figure 15 An example application of the invention for connecting a power source to an inductor, intended to heat a moving metal strip in a continuous annealing line, is schematically shown in the front view. To transmit the required power to the device, the connection between the power source 9 and the inductor 10 is established by four devices 30 according to the invention in a cross-shaped configuration, with the following characteristics:

[0054] Series-parallel configuration

[0055] Number of capacitors: 72 (4 modules with 18 capacitors)

[0056] Supply voltage: 500V

[0057] Output voltage: 2500V to 3000V

[0058] Output current: 40kA

[0059] Reactive power: 4MW

[0060] As here in Figure 15 As can be seen in FIG, the implementation of the invention allows a compact installation of the heating device, since the straight connection plate is eliminated and the distance between the power supply and the inductor is limited due to the compactness of the capacitor mounting arrangement.

[0061] As will be readily understood, the present invention is not limited to the examples just described, and various modifications may be made to these examples without departing from the scope of the present invention. In addition, the various features, forms, variations, and embodiments of the present invention may be combined in various combinations, as long as they are not incompatible or mutually exclusive.

Claims

1. A device (30) for connecting a power source (9) to an inductor (10), said device (30) comprising four connecting plates (11-14) made of a conductive material for electrically connecting a capacitor, and wherein: Any number of capacitors (7) are electrically connected to the four connection plates (11-14), the connection plates allowing electrical connection between the power source and the inductor in a parallel, series or series-parallel configuration, characterised in that the four connection plates are bent substantially through 90°, each forming two substantially mutually perpendicular half plates (31-38), each half plate being electrically connected to a different connection plate (11-14), the assembly having substantially a cross shape in a cross-sectional view.

2. The device (30) according to claim 1, characterized in that Two connecting half plates (31-38) of the same connecting plate (11-14) are separated from two other connecting half plates (31-38) of another connecting plate (11-14) by at least one plate made of insulating material and bent substantially 90 degrees.

3. The device (30) according to any one of claims 1 to 2, characterized in that The connecting plates (11-14) comprise cooling channels (22) in which a cooling fluid circulates.

4. An induction heating device, comprising a power supply (9) and an inductor (10), characterized in that: The electrical connection between the power source and the inductor is produced by at least one device (30) according to any one of claims 1-3.

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