EP3970168A1

EP3970168A1 - High voltage transformer, method for producing a high voltage transformer and test system and test signal device comprising a high voltage transformer

Info

Publication number: EP3970168A1
Application number: EP20727178.4A
Authority: EP
Inventors: Martin Anglhuber; Reinhard Kaufmann; Lukas BITSCHNAU
Original assignee: Omicron Electronics GmbH
Current assignee: Omicron Electronics GmbH
Priority date: 2019-05-13
Filing date: 2020-05-13
Publication date: 2022-03-23
Also published as: US20220246352A1; MX2021013787A; AT522601A1; CN113841209A; CA3139358A1; AU2020273556B2; WO2020229523A1; KR20220006636A; AU2020273556A1; BR112021022581A2; ZA202109185B

Abstract

The invention relates to a high voltage transformer which is designed as a toroidal transformer. Said high voltage transformer comprises a magnetisiable core (310) and a low voltage winding (330) and a high voltage winding (320 surrounding the magnetisable core (310).. The high voltage winding (330) is embodied as a Pilger step winding.

Description

High-voltage transformer, method for manufacturing a high-voltage transformer, and test system and test signal device with a high-voltage transformer

FIELD OF THE INVENTION

The invention is in the field of high-voltage measurement technology and relates in particular to high-voltage transformers, methods for their production, high-voltage test signal devices and test systems for testing a high-voltage device using a test signal with a high electrical voltage.

BACKGROUND

In electrical energy supply networks, high-voltage devices such as power transformers or switchgear - in particular gas-insulated switchgear - are usually used to convert and distribute electrical energy. Other high-voltage devices such as high-voltage converters or high-current converters - for example for measuring voltages and currents occurring in a power network -, power switches and power generators are also usually used here. Such high-voltage devices or other high-voltage devices such as electric (power) motors are also used in the industrial environment, in particular for production.

For the commissioning or maintenance of systems with such high-voltage devices, it may be necessary to check their functions and properties. Here, for example, an insulation material from a high-voltage device - such as a high-voltage current converter, a high-voltage voltage converter or a circuit breaker - can be checked, for example, by measuring the DC voltage resistance. A loss factor or a capacitance from a high-voltage device - such as a power transformer or a rotating machine, for example from a generator or an electric motor - can also be used here. can be measured, which can also provide information about a (still remaining) quality of insulating materials or insulating liquids. A partial discharge measurement can also be carried out. In order to enable in particular a measurement which reflects the conditions in real operation, high voltages can also be used as a test signal during the measurement. In addition to or as an alternative to measurements in the laboratory, measurements in the field - i.e. outdoors or in an industrial environment - are often carried out for the check.

Test devices are known for use in the field which integrate a signal generator and a high-voltage transformer or which convert a mains voltage into a high voltage by means of a variable transformer in order to generate a test signal with a high electrical voltage - i.e. in particular with a high voltage amplitude or a high effective voltage. While measures of this kind may be necessary for the operational safety of such a test device, the high-voltage winding of the high-voltage transformer or variable transformer - i.e. the winding that is electrically on the test signal side - from the other parts of the test device that are not on the high-voltage side - in particular the low-voltage winding - to isolate, the test device should have a low weight, especially for field use, and be robust for transport to the respective location.

SUMMARY OF THE INVENTION

There is therefore a need for a powerful high-voltage transformer which has a comparatively low weight and a comparatively simple structure, so that the high-voltage transformer can be produced inexpensively on the one hand and is suitable for use in a portable test device on the other. In addition, the invention is based on the object of providing a corresponding test system and a corresponding manufacturing method. According to the invention, a high-voltage transformer with the features of claim 1, a test signal device with the features of claim 10, a test system with the features of claim 12 and a manufacturing method with the features of claim 13 are provided. The dependent claims define preferred and / or advantageous embodiments of the invention.

A first aspect of the invention relates to a high-voltage transformer which is preferably designed for a test system for testing a high-voltage device. The high-voltage transformer is designed as a toroidal core transformer and has a magnetizable core, a high-voltage winding and a low-voltage winding. The high-voltage winding and the low-voltage winding are arranged around the magnetizable core in an electrically insulated manner from one another, the high-voltage winding being designed at least in sections as a pilgrim step winding.

For the purposes of the invention, “low-voltage winding” and “high-voltage winding” are to be understood as windings which have one or more turns of an electrical conductor around a (local) circumference of a transformer core of the high-voltage transformer, the electrical conductor mostly being covered by an insulation layer to avoid it is surrounded by short circuits between the individual turns. For such a winding, a coil wire or a stranded coil is usually used and wound around the transformer core along a circumferential direction, so that a current flowing through the electrical conductor induces a magnetic flux in the transformer core and the components of the magnetic flux per turn at least essentially add up. Such a winding usually extends along a (local) forward direction of the transformer core. Several of the turns of such a winding can be lined up along or opposite to the forward direction.

The electrical voltage applied to the low-voltage winding is transformed into a high voltage that can be tapped off at the high-voltage winding, depending on the turns ratio. In the context of the present invention, a voltage in the range of 1 KV and higher is regarded as "high voltage", so that the high-voltage transformer according to the invention is designed to generate and provide correspondingly high output voltages.

According to one embodiment, the high voltage provided by the high voltage transformer can in particular be such that it can serve as test voltage for testing a high voltage device.

For the purposes of the invention, a “high-voltage device” is to be understood as at least one device - for example as part of a high-voltage installation for energy supply or as part of an electrically operated production installation - which is operated with a high electrical voltage or a high electrical current, a such controls, converts or measures or can be exposed to a high electrical voltage for any other reason and should be set up for safe operation - for example through adequate electrical insulation. In particular, such a high-voltage device can be a power transformer, a (high-voltage) switchgear, a (high-voltage) circuit breaker or power switch, a high-voltage or high-voltage rotating machine such as a power electric motor or a power generator, a tap changer for a transformer or a measuring transducer such as a Be a high voltage converter or a high current converter.

In the context of the invention, a “pilgrim winding” - also “pilgrim winding” or “oblique winding” - is to be understood as at least one winding for a transformer which has several layers of turns around the transformer core, the individual layers only being along a section extend against the forward direction of the core and each (electrically) subsequent layer extends in the opposite direction - that is, opposite or along the forward direction - and partially overlaps the previous layer. In addition, those layers that extend in the forward direction extend (at least in total) further than that other layers opposite to the forward direction - or vice versa so that the pilgrim step winding extends over a larger section (compared to the sections of the individual layers) along - or correspondingly opposite - the forward direction of the core.

In some embodiments, the high-voltage winding can also be designed completely as one or precisely one pilgrim step winding. In some embodiments, the high-voltage winding can also be embodied as a plurality of pilgrim step windings, some or all of the pilgrim step windings being contiguous or adjacent to one another along the forward direction.

One advantage of the pilgrim winding can be that it enables higher frequencies to be transmitted, which in particular enables power quality measurement applications to be made with the high-voltage transformer - that is, when testing the high-voltage device, determine a load- and frequency-dependent transmission behavior of the high-voltage device over a larger frequency range leaves.

Another advantage of the pilgrim step winding can in particular be that a multi-layer winding and thus in particular a higher number of turns and / or a higher transmission ratio is made possible. In addition, contiguous or adjacent turns or correspondingly superimposed layers of the turns have a smaller voltage difference - i.e. in particular a lower (double) layer voltage - than, for example, in a multi-layer helical or wild winding, which is at least essentially over the entire core for each layer would extend. This increases the operational safety and / or the robustness and / or reduces the means required for the electrical insulation of the individual layers or of adjacent turns from one another - for example an insulating varnish around a wire for the turns or insulation layers between the individual layers Can reduce weight or reduce heat dissipation from the high-voltage winding to the magnetizable core but also to the outside, so in particular in the direction of the low-voltage winding and a surrounding area of the high-voltage transformer, can further improve.

In the context of the invention, a “toroidal core transformer” has at least one ring-shaped core with a magnetizable material - that is to say in particular a so-called toroidal core - as the transformer core. Such a toroidal core is essentially closed or almost closed in a ring shape. The toroidal core can preferably have a toroidal shape, for example in the form of a toroid or a tube section or, more generally, a rounded three-dimensional body which has a central hole. In some variants, the toroidal core can be cut through from the central hole in one section towards the outside, that is to say have a so-called air gap. In other variants, the toroidal core can be closed around the central hole, in particular along its toroidal direction, whereby in particular the magnetic flux can propagate in the magnetizable material along the alen direction without interruption.

In this advantageous way, the magnetizable core, that is to say the toroidal core, can be wound with the high-voltage winding and / or the low-voltage winding over a large (longitudinal) section in the forward direction. Another advantage of a high-voltage transformer with a toroidal core as a magnetizable core / transformer core can be that, during operation, the magnetic field lines largely run within the toroidal core, which can reduce magnetic interference fields.

One advantage of the toroidal core transformer can also be that it has a form factor that can be easily integrated into a housing.

According to some embodiments, the high-voltage transformer has a protective layer which is arranged between the high-voltage winding and the low-voltage winding. The protective layer has an electrically conductive layer for shielding the high-voltage winding from the low-voltage winding. In this advantageous way one can Reduce crosstalk between the high-voltage winding and the low-voltage winding, which, in particular when the conductive layer is connected to a suitable potential - such as a ground connection - can be used to shield interference that could spread from the high-voltage side to the low-voltage side or in the opposite direction.

According to some embodiments, the magnetizable core has an insulation layer made of an electrically insulating material for electrically insulating the magnetizable core from the low-voltage winding and from the high-voltage winding.

According to one embodiment, the high-voltage winding is arranged close to the core or directly on the magnetizable core. In this embodiment, insulation is provided between the core and the high-voltage winding. The low-voltage winding is preferably arranged around the high-voltage winding.

An advantage of the arrangement of the high-voltage winding around the magnetizable core and the low-voltage winding around the high-voltage winding can in particular be that the number of turns of the high-voltage winding is reduced and a shorter wire length is required for the high-voltage winding, which in particular allows losses to be reduced and / or that Frequency behavior can be further improved, especially for higher frequencies.

Another advantage of the arrangement of the high-voltage winding around the magnetizable core and the low-voltage winding around the high-voltage winding can be that the high-voltage winding is arranged closer to the core, which means that any heat that could occur during operation due to losses in the high-voltage winding - such as ohmic losses , can be dissipated to the magnetizable core, the high-voltage winding can therefore (at least temporarily) be cooled by heat dissipation to the magnetizable core or a temperature of the high-voltage winding can be buffered by the magnetizable core. The improved heat dissipation makes it possible to increase the performance of the high-voltage transformer and / or reduce its weight, in particular increasing a transformation ratio of the high-voltage transformer, increasing an achievable output voltage and / or a (temporarily) possible maximum electrical output power at the high-voltage winding.

According to a preferred embodiment of the invention, the magnetizable core is "floating" and has no electrical contact or no electrical connection to earth or ground. The magnetizable core is electrically isolated both from earth and from the high-voltage winding and low-voltage winding. The geometry of the high-voltage transformer can be selected such that the maximum voltage that can occur between the high-voltage winding and the magnetizable core is only half the voltage that would occur if the magnetizable core were at ground potential.

Further aspects of the invention relate to a method for producing such a high-voltage transformer, a test signal device for a test system for testing a high-voltage device, which comprises a high-voltage transformer according to the embodiments described above, and a correspondingly configured test system for testing a high-voltage device.

Further advantages, features and possible applications emerge from the following detailed description of exemplary embodiments and / or from the figures.

BRIEF DESCRIPTION OF THE FIGURES

The invention is explained in more detail below with reference to the figures on the basis of advantageous exemplary embodiments. The same elements or components of the exemplary embodiments are essentially given the same reference symbols unless otherwise stated or if the context does not indicate otherwise.

To this end show, partly schematically:

1: a high-voltage transformer according to an embodiment;

Fig. 2: a cross section through the high voltage transformer of Fig.

1 ;

3: a longitudinal section through a high-voltage transformer according to a further embodiment;

4: a test system according to an embodiment; and

FIG. 5: a flow diagram of a method for producing a high-voltage transformer according to an embodiment.

The figures are schematic representations of various embodiments and / or exemplary embodiments of the present invention. Elements and / or components shown in the figures are not necessarily shown true to scale. Rather, the various elements and / or components shown in the figures are reproduced in such a way that their function and / or their purpose can be understood by a person skilled in the art.

Connections and couplings between functional units and elements shown in the figures can also be implemented as indirect connections or couplings. In particular, data connections can be wired or wireless, that is to say in particular as a radio connection. Certain connections, for example electrical connections, for example for energy supply, can also not be shown for the sake of clarity. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 schematically shows a high voltage transformer 300 according to an embodiment of the present invention.

The high-voltage transformer 300 has a magnetizable core 310, 31 1, a low-voltage winding 320, a high-voltage winding 330 and a protective layer 340. The low voltage winding 320 and the high voltage winding 330 extend along a forward direction 316 of the magnetizable core. In this case, the high-voltage winding is arranged at least around a part, in particular a longitudinal section, of the magnetizable core 310, 31 1 and is designed as a pilgrim step winding. In the exemplary embodiment shown, the high-voltage winding 330 is located directly on the magnetizable core 310, 31 1. The protective layer 340 is arranged around the high-voltage winding 330, which has an insulating material and thus electrically insulates the low-voltage winding 320, which is arranged further outward relative to the high-voltage winding and the protective layer 340, from the high-voltage winding 330.

The low voltage winding 320 has multiple turns 328. In some advantageous variants, the windings 328 can be wound helically in the direction of the forward direction 316 around the magnetizable core 310 and correspondingly in the case of parts with the high-voltage winding 330 or the protective layer 340 also wound around these. For this purpose, in some variants, an enamel-insulated coil wire, in particular made of copper, can be helically wound around the magnetizable core 310.

In the embodiment shown, the windings are shown for only a portion 310 of the magnetizable core for the sake of simplicity. The high-voltage transformer 300 is designed as a toroidal core transformer, so that the high-voltage winding 330 and the low-voltage winding 320 actually extend in a ring shape along the entire length of the ring-shaped magnetizable core 310, 31 1. Alternatively, it is also possible that several electrically interconnected High-voltage windings 330 and / or several electrically interconnected low-voltage windings 320 or several sections of high-voltage winding 330 and / or several sections of low-voltage winding 320 are arranged at a distance from one another or also superimposed along different longitudinal sections 310, 31 1 of the magnetizable core, so that a total of a toroidal transformer is formed.

The core 310, 31 1 is annularly closed or almost closed, wherein in the last-mentioned case the annular core 310, 31 1 is only interrupted by an air gap. The ring shape can be toroidal, however, as shown in the figures, angular designs are also possible.

2 shows a cross-section through the high-voltage transformer 300 to illustrate its structure from the inside - that is, from the magnetizable core - to the outside - that is, towards the low-voltage winding -, the cross-section being at least substantially perpendicular to the forward direction of the magnetizable core.

The high-voltage winding 330 is arranged concentrically around the magnetizable core 310. The protective layer 340 is then arranged concentrically around the high-voltage winding 330. Finally, the low voltage winding 320 is arranged concentrically around the protective layer 340. The high-voltage winding 330 is thus arranged further inside and the low-voltage winding 320 further outside, relative to one another or relative to the protective layer 340, so that the high-voltage winding 330 is closer to the magnetizable core 310. In some advantageous variants, the high-voltage winding 330 touches the magnetizable core or is only separated from it by an insulation layer (not shown in FIG. 2), which enables improved thermal coupling between the high-voltage winding 330 and the magnetizable core 310, thereby increasing the performance can be.

In some advantageous variants, the protective layer 340 has, as shown, a first electrically insulating layer 342, an electrically conductive layer 344 and a second electrically insulating layer 346. On this, the high-voltage winding and the low-voltage winding can advantageously be shielded from one another by means of the electrically conductive layer 344 and the electrically conductive layer 344 can be electrically insulated both from the high-voltage winding by means of the first electrically insulating layer 342 and from the low-voltage winding by means of the second electrically insulating layer 346. In some variants, the first electrically insulating layer 342 can be galvanized and the electrically conductive layer 344 can thus be applied thereon. In other variants, the electrically conductive layer 344 can also be vapor-deposited (in particular as metal vapor) or glued on (in particular as metal foil). Furthermore, in some variants, the second electrically insulating layer 346 can be omitted.

3 shows a longitudinal section through a high-voltage transformer according to a further embodiment of the present invention to illustrate the high-voltage winding designed as a pilgrim winding, with any further components such as the protective layer, the low-voltage winding or a magnetic connecting element not being shown for the sake of clarity.

The high-voltage transformer shown in FIG. 3 can correspond to the high-voltage transformer 300 described with reference to FIG. 1 and / or FIG. 2, the longitudinal section being at least essentially along the forward direction of the magnetizable core, so that the forward direction 316 lies at least essentially in the cutting plane.

The forward direction 316 is illustrated in Fig. 3 by a dashed, turning arrow, wherein the forward direction is to be understood relative to the respective position in the magnetizable core 310 and to a possible magnetic flux and consequently represents a local direction, which in particular each locally in the direction of a shows any magnetic flux (or always against this direction). If the forward direction is followed locally in the case of a closed magnetizable core, a closed curve is obtained that encloses exactly one area. The high-voltage winding 330 has several turns, which are grouped into several groups 335 of turns, which are wound electrically in series and helically in the forward direction around the magnetizable core 310 per group, and in several groups 336 of turns, which are electrically in series per group and are helically wound against the forward direction around the magnetizable core. The groups 235 and 236 are alternately connected electrically in series with one another and each alternately wound around the magnetizable core 310, so that on a first number of turns in the forward direction for one of the groups 335 a second number of turns against the device for one of the groups 236 follows. In addition, the first number is greater than the second number, so that overall there is a winding in the forward direction.

To produce the high-voltage winding 330, a coil wire can alternately be wound around the core 310 in the forward direction for the first number of turns and wound around the core 310 in the reverse direction - that is, against the forward direction - for the second number of turns. In some advantageous variants, the coil wire can be an enamel-insulated copper wire.

By winding in the forward direction and counter to the forward direction, compared to a helical winding, more turns can be wound around a length of the magnetizable core 310 only in the forward direction or only in the reverse direction. As a result, a large number of turns can be achieved overall without the need for a further layer or layer of turns which would extend over all the length sections of the magnetizable core intended for winding. Because individual length sections of the magnetizable core are wound forwards and backwards in the pilgrim step winding, the length sections (so to speak) have several layers locally, the voltage difference between these "local layers" being smaller than with a multi-layer or multi-layer winding which turns are each wound over a total length of the magnetizable core to be wound. For example, as shown in FIG. 3, the turn 338 of one of the groups 336 is spatially adjacent to the turns 337 and 339 of one of the groups 335 and also electrically only one or only two turns away from them, whereby a relative between the turns there is a small voltage difference in the operation of the high-voltage transformer.

In some variants, the magnetizable core 310 can also have an insulation layer 314. This can, as shown in FIG. 3, be connected to the core and only cover a part, in particular a length section to be wound, that of the core 310 or else surround the entire core 310 and thus electrically isolate it. In some variants, this can be particularly advantageous in combination with a magnetizable core 310 made of core sheet, in particular made of several layers of core sheet, which in particular can be wound to form a toroidal core.

4 shows a test system 10 according to an embodiment of the present invention together with a high-voltage device 30 to be tested as a schematic block diagram, with some components of the test system and associated electrical connections, connection points and / or node points as an electrical (principle) circuit diagram for a more detailed illustration are shown.

In one embodiment, the test system 10 includes a portable main device 100 and a portable high-voltage test signal device 200. The high-voltage test signal device 200, as a portable additional device of the test system 10, enables additional (test) functions - in particular those functions that are based on a high voltage - in addition to functions that the portable main device already provides.

The portable main device 100 has a housing and a power output 120 integrated into the housing. The portable high-voltage test signal device 200 has a housing and a power input 220 integrated into the housing. The power output 120 and the power input 220 are electrically connected by means of a cable 20 during operation, that is to say for testing the high-voltage device 30.

The portable high-voltage test signal device 200 also has a test signal device 230, the components of which are accommodated in the housing of the high-voltage test signal device 200. A first test connection 232 and a second test connection 234 of the test signal device 230 can be integrated in the housing of the portable high-voltage test signal device 200 in a manner corresponding to the power input 220.

During operation, that is to say when testing the high-voltage device 30, the first test connection 232 is electrically connected to a first connection point 32 of the high-voltage device 30 and, correspondingly, the second test connection 234 is electrically connected to a second connection point 34 of the high-voltage device 30.

For grounding, the portable high-voltage test signal device 200 can have a grounding connection 204, which in particular enables separate grounding - for example for increased operational safety. Alternatively, one of the test connections can also serve as a ground connection, which in particular enables simpler cabling.

The test signal device 230 has the high-voltage transformer 300 according to one of the previously described embodiments, the high-voltage transformer 300 being shown only schematically in FIG. 4 with the magnetizable core 310, the low-voltage winding 320 and the high-voltage winding 330 and the protective layer 340. The magnetizable core 310 is designed as a toroidal core, which in particular enables low interference radiation, a compact design and a form factor that can be easily integrated into a housing and thus a particularly easy-to-transport high-voltage test signal device 200. This compact design is synergistically supported by the high-voltage winding 330, which is preferably close to the core - and thus in particular thermally buffered by means of the magnetizable core 310. As mentioned earlier, both the low voltage winding 320 and the high-voltage winding 330 can be formed by a suitable number of partial windings.

As shown in FIG. 4, the high-voltage winding 330 has a first connection point 332 and a second connection point 334, the second connection point 334 being electrically connected to the second test connection 234. The first connection point 332 can be electrically connected to the first test connection 232, whereby these can be connected directly to one another or, as shown, by means of an electrical switch 238 of the test signal device 230. The switch 238 enables the first connection point 332 and the first test connection 232 to be selectively to be electrically connected, so that the electrical connection for applying a high voltage to the high-voltage device 30 can be established and, for example, can be disconnected between individual test procedures for safety.

The low-voltage winding 320 has a first connection point 322 and a second connection point 326. The first and the second connection point 322, 326 are electrically connected to the power input 220 in such a way that a power signal can be applied between the two connection points 322, 326 via the power input 220.

To generate the power signal, the portable main device 100 has a power signal source 130, in particular a controllable voltage source, which is electrically connected to the power output 120. The portable main device 100 is set up to control the power signal source 130 such that an electrical voltage is applied between the first and second connection points 322, 326 of the low-voltage winding 320 via the power signal and the high-voltage transformer 300 converts this voltage into a test signal for testing the high-voltage device 30, which is applied between the first and second connection point 332, 334 of the high-voltage winding 330 - and thus also between the first and second test connection 232 and 234 when the switch 238 is closed. The portable main device 100 is preferably designed in such a way that it controls the test sequence with the aid of an integrated controller (not shown in FIG. 4) with the aid of the test signal generated by the high-voltage transformer 300.

FIG. 5 shows a flow diagram of a method 800 for producing a high-voltage transformer according to an embodiment of the present invention.

In one embodiment, the method 800 has the method steps 810, 820, 830 and 840. The method 800 begins at the method start 802 and ends at the method end 804, the method steps being carried out in the following sequence and some variants of the method - for example for producing certain embodiments, developments, variants or exemplary embodiments according to the description and / or according to the figures - May have further process steps.

In method step 810, a magnetizable core is provided for the high-voltage transformer configured as a toroidal core transformer.

In method step 830, a coil wire is wound around the magnetizable core at least in sections as a pilgrim step winding, so that a high-voltage winding of the high-voltage transformer is formed.

In method step 840, a protective layer is applied which envelops the high-voltage winding on a side facing away from the magnetizable core and electrically isolates the high-voltage winding in the direction of the side facing away.

In method step 820, a coil wire is wound around the high-voltage winding covered by the protective layer, so that a low-voltage winding of the high-voltage transformer has a smaller number of turns than a number of turns of the high-voltage winding is formed and the protective layer electrically isolates the high-voltage winding and the low-voltage winding from one another.

Claims

PATENT CLAIMS

1 . High voltage transformer (300),

wherein the high-voltage transformer (300) is designed as a toroidal core transformer and has:

a magnetizable core (310);

a low voltage winding (320) which is arranged around the magnetizable core (310); and

a high-voltage winding (330) which is arranged around the magnetizable core (310) and is electrically insulated from the low-voltage winding (320),

wherein the high-voltage winding (330) is designed at least in sections as a pilgrim step winding.

2. High-voltage transformer (300) according to claim 1, wherein the high-voltage winding (330) is arranged directly around the magnetizable core (310).

3. High-voltage transformer (300) according to claim 1 or claim 2, wherein the low-voltage winding (320) is arranged around the high-voltage winding (330).

4. High-voltage transformer (300) according to one of the preceding

Claims, wherein the high-voltage winding (330) extends with at most one circumference along a forward direction (316) around the magnetizable core (310) and wherein the forward direction is locally in each case along a direction of the magnetizable core (310).

5. High-voltage transformer (300) according to one of the preceding

Claims, further comprising a protective layer (340), which is arranged between the high-voltage winding (330) and the low-voltage winding (320), wherein the protective layer (340) is configured such that it High-voltage winding (330) and the low-voltage winding (320) are electrically isolated from one another.

6. High-voltage transformer (300) according to claim 5, wherein the protective layer (340) has an electrically conductive layer (344) for shielding the high-voltage winding (330) from the low-voltage winding (320)

7. High-voltage transformer (300) according to one of the preceding

Claims, wherein the magnetizable core (310) has an insulation layer (314) for its electrical insulation from the low-voltage winding (320) and high-voltage winding (330).

8. High-voltage transformer (300) according to one of the preceding

Claims, wherein the magnetizable core (310) has no electrical ground or ground connection.

9. High-voltage transformer (300) according to one of the preceding

Claims, wherein the high-voltage transformer is designed to generate a high-voltage test signal for a test system (10) for testing a high-voltage device (30).

10. Test signal device (230) for a test system (10) for testing a high-voltage device (30), comprising:

a high voltage transformer (300) according to any one of claims 1-9; wherein the test signal device (230) is set up to generate a test signal by means of the high-voltage transformer (300) which is applied between a first connection point (332) and a second connection point (334) of the high-voltage winding (330) of the high-voltage transformer (300), and to to provide the test signal for testing the high-voltage device (30).

1 1. Test system (10) for testing a high-voltage device (30), comprising a portable main device (100) with a housing and a portable additional device (200) with a separate housing that can be electrically connected to it; wherein the portable additional device (200) is designed as a portable high-voltage test signal device (200) and has a test signal device (230) according to claim 10; and

wherein the portable main device (100) is set up to control the generation of the test signal by the high-voltage transformer (300) of the portable auxiliary device (200) for testing the high-voltage device (30).

12. A method for producing a high-voltage transformer (300), wherein the high-voltage transformer (300) is produced as a toroidal core transformer, and

the method comprising:

- providing an annular magnetizable core (310);

- Winding a high-voltage winding (330) at least in sections as a pilgrim step winding around the magnetizable core (310); and

- Winding a low voltage winding with a smaller number of

Turns as a number of turns of the high-voltage winding (330) around the magnetizable core (310).

13. The method according to claim 12, wherein the method for producing the high-voltage transformer (300) according to any one of claims 1-9 is carried out.