Coil assembly for power transformer

Abstract

The invention relates to a coil assembly (20) for a power transformer (100), in which the coil assembly (20) comprises two identical high-voltage coils (10) connected in parallel, and each high-voltage coil is configured as a transformer having a primary winding (11) and a secondary winding (12). The invention also relates to a corresponding power transformer and to the use of a coil assembly in such a power transformer.

Description

Technical Field

[0001] The invention relates to a coil assembly, in particular to a coil assembly for an inductive power transformer, in particular, the power transformer is used for voltage conversion in an energy supply system of high voltage technology. Background Art

[0002] Such a power transformer is preferably configured as or similar to a transformer or transformer device, which is directly connected on the primary side to a high voltage line or busbar for high voltages, for example up to several hundred kilovolts. On the secondary side, power can be provided at a relatively low secondary voltage, for example up to several hundred volts. Such a transformer device is suitable, for example, for self-powering of a transformer substation or for supplying energy from a high voltage network to rural areas or construction sites.

[0003] In order to increase the power of such a transducer, an obvious measure is to adjust, for example, the cross section of the wire or conductor so that the power loss in the device can be adjusted to the corresponding output power. However, this leads to a larger space requirement for the two windings and thus a larger or less compact size of the entire active part. Alternatively or additionally, the inductance and the core cross section of the magnetic core used can be varied within certain limits, optimizing the power by adjusting the parameters of the number of windings.

[0004] However, an increase in the core cross-section or core window size results in higher core costs and in an increase in coil size (particularly relative to the width and height of the windings), which in turn negatively affects heat dissipation from the component.

[0005] Furthermore, the increased coil size also disadvantageously results in a higher production cost for the entire component, due to the greater use of material, in particular the housing and the voltage connections may also have to be adjusted or configured differently. In particular, the greater coil weight has a negative impact on the connection or installation of the component, since larger cranes or installation equipment must be provided, and / or more complex support. Summary of the invention

[0006] It is therefore an object of the present invention to provide an improved coil assembly for a power transformer which in particular allows the component in question to be supplied with a significantly increased total current or to be operated with a significantly increased total power.

[0007] This object is achieved by the subject matter of the independent claims. The dependent claims relate to advantageous embodiments.

[0008] One aspect of the invention relates to a coil assembly for, in particular, an inductive power transformer, wherein the coil assembly comprises at least two (i.e., two or more) high-voltage coils of the same type, which are connected in parallel or are to be or can be interconnected accordingly. The high-voltage coils are each constructed in the manner of a transformer having a high-voltage side primary winding and a low-voltage side secondary winding. Accordingly, the high-voltage coil is preferably a coil or coil component configured on the primary side for high-voltage applications.

[0009] Furthermore, the coil assembly according to the invention is preferably configured for power transformer applications, in particular in single-phase operation.

[0010] The (primary-side) parallel interconnection of the two coils means that at the same core cross section, the total current and thus the total power can be advantageously increased (in particular doubled) and the above-mentioned disadvantages are prevented. As a result, the power transformer as a component can provide, extract or process significantly higher power (output power).

[0011] Furthermore, the thermal performance of each individual coil (single high voltage coil) is advantageously maintained without the above-mentioned disadvantage of having to provide a larger coil which is characterized by significantly poorer heat release properties.

[0012] Furthermore, the housing diameter is advantageously similar or identical to the diameter of a device of similar design which only provides, for example, half the output power.

[0013] Advantageously, when using a coil assembly according to the invention in a power transformer, the size of the housing only needs to be increased in one dimension, which is much less costly than increasing the size of the conductor or core cross section.

[0014] Furthermore, due to the two separate or individual coils or coil pairs, handling of the coil assembly for the stated purpose during installation is advantageously facilitated.

[0015] In one embodiment, the secondary windings of the high voltage coils are arranged at the inner side of the coils or coil components, and the primary windings are located at the outer side.

[0016] In one embodiment, the two high-voltage coils of the same type are identically configured or processed. This embodiment particularly provides the advantages described in detail above, namely installation, commissioning and the overall dimensions of the coil assembly for its intended use. However, in contrast to this embodiment, the advantages according to the invention can also be partially applied to the case of high-voltage coils that are merely of the same type but not completely identical.

[0017] In one embodiment, the two high-voltage coils of the same type are symmetrically arranged on a common magnetic core of laminated and / or pressed iron sheets, or arranged in a tape-wound core configuration. This embodiment is particularly beneficial to the electrical characteristics of the coil assembly for transformer applications in high voltage technology, in particular to reducing losses and improving efficiency.

[0018] In one embodiment, the primary windings of the high voltage coils are wound such that the corresponding magnetic field strengths in the magnetic cores - during intended operation of the coil assembly or transformer - have the same sense of direction or the same (rotating) field direction.

[0019] In one embodiment, the primary windings are respectively wound or configured to be rotationally symmetrical, such as in a ring or plate shape. This embodiment is particularly beneficial to the electrical characteristics of the coil assembly for transformer applications, and is particularly beneficial to reducing losses and improving efficiency.

[0020] In one embodiment, the primary windings of the two high-voltage coils of the same type are each configured to be electrically connected in parallel to the high voltage to be converted.

[0021] In one embodiment, the coil assembly is configured to increase (particularly double) the total secondary-side current or power of the power transformer compared to a comparable model or component of a high voltage coil having the same core cross-section.

[0022] In one embodiment, the coil assembly is not suitable for cascade arrangement of individual high voltage coils, or the corresponding coil components are not electrically connected in series.

[0023] Another aspect of the invention relates to a power transformer comprising such a coil assembly, wherein two high-voltage coils of the same type are arranged in parallel. Such a design and embodiment of a power transformer enables the advantages according to the invention to be used for advanced components also in the case of a compact design.

[0024] In one embodiment, the two high voltage coils of the same type are arranged one vertically above the other, according to the intended assembly arrangement of the power transformer. This embodiment advantageously allows a compact design of the power transformer.

[0025] In one embodiment, the two high voltage coils of the same type are arranged or wound on opposite legs of a common magnetic core of the coil assembly. This embodiment also advantageously allows a compact design of the coil assembly.

[0026] In one embodiment, the main insulating medium in the enclosure of the power transformer is gaseous during operation (particularly synthetic or purified air). This embodiment conveniently allows providing reliable insulation while eliminating climate-damaging sulfur hexafluoride as an insulating medium.

[0027] Another aspect of the invention relates to the use of the above-described coil assembly to increase, in particular to double, the total current and / or the total power of a power transformer.

[0028] Embodiments, features and / or advantages relating in the present case to a coil assembly may also be directly relevant to a power transformer, and vice versa.

[0029] As used herein, the expression "and / or" or "or" used in a series of two or more elements means that each listed element may be used alone or any combination of two or more listed elements may be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] More details of the present invention will be described below with reference to the accompanying drawings.

[0031] Figure 1 A known design of an inductive power transformer comprising a single (high voltage) coil assembly is shown.

[0032] Figure 2 An embodiment of a power transformer comprising a coil assembly according to the invention is shown, the coil assembly comprising two (separate) high voltage coil parts connected in parallel. DETAILED DESCRIPTION

[0033] In the embodiments and figures, identical or functionally identical elements may have the same reference numerals in each case. The elements shown and their size ratios relative to one another are not to be understood as true to scale in principle, but individual elements may be shown with exaggerated thickness or size for better illustration and / or better understanding.

[0034] Figure 1 A conventional power transformer 100 is shown comprising a known coil arrangement. The coil shown conveniently constitutes a high-voltage coil 10 or a coil pair with a high-voltage winding. In other words, the high-voltage coil 10 comprises a primary winding 11, which is connected, for example, to the voltage to be converted, and a secondary winding 12. Accordingly, the coil is preferably configured as a transformer, so that high-voltage measurements can be made in high-voltage technical energy supply systems, such as Figure 2 The same coil arrangement according to the invention is described in .

[0035] In addition, the coil 10 includes a magnetic core 21, which is conveniently configured for high frequency applications and is preferably made of iron plate. The other parts of the power transformer including the coil 10 are Figure 1 The components are partially shown in the figure, but are not explicitly indicated by a reference numeral.

[0036] In some applications of such transformers for high voltage applications, it is necessary to increase the power output, or increase the total current on the secondary side and the total power of the components. The coil assembly for an inductive power transformer according to the present invention meets this requirement.

[0037] Figure 2 A component 100 according to the invention is described in the accompanying drawings. The power transformer 100 according to the invention comprises an improved coil assembly 20. Figure 1 Compared to the components of the present invention, the coil component 20 according to the present invention includes at least two high-voltage coils 10 of the same type connected in parallel, wherein the two high-voltage coils 10 are each configured to have a transformer-like structure having a primary winding 11 and a secondary winding 12.

[0038] The secondary windings 12 of the two coil assemblies 10 are arranged further inside the coil (only visible to a certain extent in this example), while the high-voltage-side primary winding 11 is located further outside.

[0039] All or individual coil windings can be insulated from one another, for example, or the individual layers can be insulated with oil paper.

[0040] The windings of the high-voltage coil 10 (in particular their primary windings 11) are again arranged in a plate-like or annular manner around a magnetic core 21. This magnetic core 21 can be used for AC voltage applications or power supply operations and is preferably prefabricated from laminated or pressed iron sheets during the production process of the coil assembly. Then, the windings of the coil are preferably first wound on a support tube and then the magnetic core is closed to complete the magnetic field closure.

[0041] Preferably, the high-voltage coils 10 of the same type are designed to be identical.

[0042] In addition, Figure 2 As can be seen in FIG. 1 , the two high-voltage coils 10 of the same type are symmetrically arranged on the magnetic core 21. In addition, the high-voltage coils 10 are arranged in parallel in the upper component of the power transformer 100, and one is arranged above the other. For this purpose, Figure 2 Also shown is an electrical connection or feed-through 13 between the two separate coil assemblies.

[0043] Figure 2 Also shown are two high voltage coils 10 of the same type arranged on opposite legs of a common magnetic core 21 of a coil assembly 20 or wound thereon.

[0044] Reference numeral 101 denotes a (primary) insulating medium 101 in a housing (not further shown) or a box of the power transformer 100 , which insulating medium 101 may be gaseous, preferably synthetic air or purified air.

[0045] Unlike what is shown in the current figures, it is understood that the present invention also includes corresponding triple, quadruple or multiple assemblies of high-voltage coils of the same type, which can be configured, wound or interconnected similarly to the two high-voltage coils of the same type described, and are therefore associated with the advantages according to the present invention. In other words, therefore, according to the present invention, more than two (i.e., for example three, four or even more) high-voltage coils 10 of the same type can also be wound or arranged (i.e., connected in parallel) around the magnetic core 21.

[0046] When a plurality of single high-voltage coil assemblies of the same type and of a specific design are assembled in parallel one above the other according to the invention, a particularly compact design of the transformer can be achieved. However, primarily, the design also enables the total power or total output current of the power transformer to be advantageously increased (in fact, in particular advantageously doubled). In particular, compared with the design according to Figure 1 Compared to the component shown, this technical advantage is achieved in a component of the same core cross section without requiring further design of the component or adjustment or optimization of further parameters.

[0047] Typically, the high voltage of a transformer for an energy supply device is tapped via a high voltage connection piece, in particular an aluminum tube 2. Furthermore, in this case, the component advantageously comprises an insulator 1 surrounding the voltage connection piece 2, such as Figure 2 shown.

[0048] In the present case, the power transformer 100 is only partially or schematically shown. However, it is obvious that the coil concept according to the invention can in principle be used for any type of inductive transformer, since it will be applied in a correspondingly scalable manner. Therefore, it can be used in a variety of designs of power transformers.

Claims

1. A coil assembly (20) for a power transformer (100), wherein: The coil assembly (20) comprises two high-voltage coils (10) of the same type connected in parallel, wherein the two high-voltage coils are each configured as a transformer structure having a primary winding (11) and a secondary winding (12).

2. The coil assembly (20) according to claim 1, wherein: The secondary windings (12) are arranged on the inner side of the coils, and the primary windings (11) are arranged on the outer side.

3. The coil assembly (20) according to claim 1 or 2, wherein: The two high-voltage coils (10) of the same type are identically configured.

4. The coil assembly (20) according to any one of the preceding claims, wherein: The two high-voltage coils (10) of the same type are arranged on a magnetic core (21), and the magnetic core (21) is made of laminated iron sheets or configured as a tape-wound magnetic core.

5. The coil assembly (20) according to claim 4, wherein: The primary winding (11) of the high-voltage coil (10) is wound so that the corresponding magnetic field intensities in the magnetic core have the same sense of direction.

6. The coil assembly (20) according to any one of the preceding claims, wherein: The primary windings (11) of the two high-voltage coils of the same type are each configured to be electrically connected to the high voltage to be transformed.

7. The coil assembly (20) according to any of the preceding claims, being configured to increase the total power of the power transformer, in particular to double the total power of the power transformer, compared to components of the same core cross section.

8. A power transformer (100) comprising a coil assembly (10) according to any one of the preceding claims, wherein: The two high-voltage coils (10) of the same type are arranged in parallel.

9. The power transformer (100) according to claim 8, wherein: According to the intended assembly arrangement of the power transformer, the two high-voltage coils (10) of the same type are arranged one above the other.

10. The power transformer (100) according to claim 8 or 9, wherein: The two high-voltage coils (10) of the same type are arranged on opposite legs of a common magnetic core (21) of the coil assembly (20).

11. The power transformer (100) according to any one of claims 8 to 10, wherein: The insulating medium is gaseous, in particular synthetic air or purified air.

12. Use of the coil assembly (20) according to any one of claims 1 to 7 for increasing the total current and / or total power of a power transformer (100).

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