DE102016206124A1 - Height-adjustable EMC test bench - Google Patents

Abstract

A test stand for performing an EMC measurement on a test object to be measured is provided, comprising a platform for receiving the test object to be tested and a substructure supporting the platform, wherein the test bench comprises at least one height adjustment device for selectively setting a ground clearance of the platform. Furthermore, a method for performing an EMC measurement on a test object to be measured is described.

Description

The invention relates to a test stand for performing an EMC measurement on a test object to be measured according to the preamble of patent claim 1.

In order to safeguard the development process of a motor vehicle, its electrical components or systems are subjected to electromagnetic compatibility measurements (so-called EMC measurements) in order to obtain a statement as early as possible on a homologation capability of the later overall vehicle. For this purpose, the electrical components and systems are usually on table-like test stands with regard to their electromagnetic compliance according to the specifications of general standards, such as Standard CISPR25 , checked. This standard basically defines the geometry of the test setup.

From the DE 100 49 192 A1 For example, a mobile test bed construction on a mobile pallet construction is known with which during the production process, in particular in internal combustion engines for motor vehicles Funktionsprüf- and Einstellumfänge are controllable.

Furthermore, in the DE 10 2012 212 886 A1 a mobile test rig structure for performing an EMC measurement of drive motors described.

The EMC measurements are carried out according to standards in so-called absorber halls, which usually have a metallic floor. The parasitic capacitance that forms between the floor and the test stand can play a major role and thus considerably complicate a correlation of the test setup with a later, actual arrangement in a complete vehicle.

The object of the invention is therefore to refine such a test rig structure in such a way that the most optimal and individually adaptable correlation of the test setup with respect to electromagnetic properties to different vehicles and test standards is made possible.

The object is achieved with a test stand having the features of patent claim 1.

Accordingly, a test stand for performing an EMC measurement is provided on a test specimen to be measured, with a platform for receiving the test specimen to be tested and a base supporting the platform, wherein the test stand comprises at least one height adjustment device for selectively setting a ground clearance of the platform.

With the help of such test benches, for example, drive motors in the form of internal combustion engines and electrical machines can be subjected to an EMC measurement at various operating points. Likewise, the test stands are usually also used for the testing of propulsion systems of any hybrid vehicles (for example, serial hybrid, parallel hybrid, power-split hybrid, mild hybrid or full hybrid). It goes without saying that corresponding measurements on other electrical components and systems with these test stands are also possible.

Due to the one or more height adjustment device (s), the distance of the platform to the floor supporting the test stand, ie the ground clearance, can be set as desired or varied in a simple manner. Thus, electrical properties resulting from the geometric boundary conditions, change and thus approach individually to the boundary conditions of the vehicle to be simulated.

With the help of the height adjustment, it is thus possible to achieve a high correlation between the test arrangement of the test object to be measured and the later overall vehicle.

ab. ε₀ steht hierbei für die elektrische Feldkonstante des Vakuums und ε_r für die dielektrische Leitfähigkeit des Dielektrikums, also üblicherweise Luft.It has been recognized that parasitic capacitances that form between different circuits are a significant influencing factor in the electromagnetic compatibility test. Each circuit of the vehicle is significantly influenced by the parasitic capacitance C _Fzg between the commonly used metallic floor and the vehicle. This depends, on the one hand, on the base area of the vehicle A _Fzg and its underbody _height h _Fzg above the metallic floor according to _FIG

from. ε ₀ stands for the electric field constant of the vacuum and ε _r for the dielectric conductivity of the dielectric, ie usually air.

For the parasitic capacitance of the test bench, the analogous relationship between the base area of the test stand A _Pst and the height h _{Pst of} the test bench above the floor slab is determined according to:

Both the base area A _{Fzg of} the vehicle and the base area of the test stand A are _Pst to be understood as areas within a plane aligned parallel to the ground.

For an optimum correlation of the measurements on the test bench and the measurements on the vehicle, therefore, an ideal state is sought in which the parasitic capacitance of the test bench is equal to the parasitic capacitance of the later vehicle: thus C _Pst = C _Fzg . An equalization of both parasitic capacitances can preferably be achieved by varying the ground clearance according to the description.

The adjustment of the ground clearance can for example be done in two different ways: (i) by a height adjustment of the entire platform itself and / or by (ii) lowering a lower edge of the platform.

Accordingly, a first height adjustment device (the at least one height adjustment device) can be designed for height adjustment of the platform. This allows by pressing the first height adjustment the entire platform either raise or lower to make the desired height adjustment of the platform and thus bring a specimen bearing the top of the platform to the defined height. Preferably, the first height adjustment device is integrated in the substructure.

In any case, the first height adjustment device thus allows the setting of the desired ("table") height of the platform, which is provided for receiving the test object to be tested. In this case, the desired height can result, for example, from specification of a standard or a standard for carrying out such EMC measurements. Likewise, the possibility for the most accurate adaptation to different vehicle geometries is given.

For example, the height adjustment takes place within the substructure, so that the platform arranged above remains unchanged and is moved only in its height, whereby their ground clearance is variable.

The first height adjustment device may comprise a lifting mechanism for height adjustment of the platform, in particular a lifting mechanism with height-adjustable legs or a scissor-type lifting mechanism.

Alternatively or additionally, the test stand may comprise a second height adjustment device of the at least one height adjustment device, which is designed to lower a lower edge of the platform relative to an upper edge of the platform. For example, the upper edge of the platform is to be understood, which should be provided for receiving the test specimen and should have a defined height in accordance with defined standards. The top edge can also be defined by additional structures that are integrated in the platform.

With the help of the second height adjustment device, it is thus possible to lower a part of the platform, or more precisely its lower edge, as required, with respect to the rest of the platform. The bottom edge is in particular a lower edge of the platform forming the lower edge or a subsection of this lower side. A ground clearance between the floor supporting the test stand and the lowerable lower edge of the platform can be easily changed in this way. At the same time, a height of the upper edge of the platform can be maintained.

If both the first and the second height adjustment device are provided, the height of the upper edge and the ground clearance of the lower edge of the platform can be adjusted independently of each other and thus optimally match the electromagnetic properties of the test stand to the desired electromagnetic properties of the entire vehicle.

The capacity C _{Pst of} the test stand results in the case of using the second height adjustment _device (alone or together with the first height adjustment device) from the sum of all surface and height elements of the test stand to the ground, for example, the hall floor, to:

This is helpful, for example, if requirements of test standards have to be complied with. However, given the (ideally standard-compliant) height of the upper edge of the platform, capacity can still be adjusted by lowering the lower edge and adjusting the desired capacity of the test bench.

Furthermore, the platform may comprise an electrode element defining the bottom edge of the platform.

For example, the electrode element can be designed in the shape of a plate and, by means of the second height adjustment device, can be made lowerable parallel to the upper edge of the platform.

According to a further embodiment, the electrode element is electrically conductively connected to the upper edge of the platform by means of a low-impedance, flexible conductor. The leader can for example, have a flat shape, wherein the planar conductor has a large width in relation to the thickness. For example, the planar conductor can be designed in sheet metal form. Such a conductor allows a niederimpedante electrical connection between the upper edge and the lowered lower edge of the platform despite their spatial separation due to the intended Absenkbarkeit.

In addition, the at least one height adjustment device can be actuated mechanically, electrically, pneumatically and / or hydraulically. Accordingly, the first and / or the second height adjustment device may comprise corresponding actuators and kinematics.

According to another embodiment, the platform comprises a pallet construction. The pallet construction may include one or more pallet-shaped elements. A particular simplification may be a pallet construction based on standard EURO-2000 type pallets.

Furthermore, the test stand can be designed to be mobile. For this purpose, the test bench includes, for example, wheels that allow a simple movement of the entire test bench.

Further, the platform may include an integrated dynamometer drive system for operating the specimen, the dynamometer drive system having an EMC shield. For example, a drive motor of a drive system test object can be operated with the aid of the test bed drive system. For this purpose, the test bed drive system comprises in particular a test bench motor with an electronic control unit with further control elements and components. Optionally, the test bed drive system is integrated in the platform, preferably in the pallet construction of the platform, and includes EMC shielding.

In any case, the EMC shield is preferably designed such that the electromagnetic interference emission of the test bed drive system is below the measurement noise of the measurement technique used for the EMC measurement. For this purpose, individual controls and components of the test bed drive system, but also the entirety of the test bed drive system, be shielded accordingly.

A power supply of the test bed drive system can be a high-voltage source or a high-voltage store assigned to the drive system test object, in particular a vehicle battery and / or so-called "supercaps", which can optionally also be integrated in the platform.

• a. Bereitstellen eines Prüfstandes, mit einer Plattform und einem die Plattform tragenden Unterbau, wobei der Prüfstand mindestens eine Höhenverstellvorrichtung zum wahlweisen Einstellen eines Bodenabstandes der Plattform umfasst,
• b. Betätigen der mindestens einen Höhenverstellvorrichtung zum Einstellen des Bodenabstandes auf einen vordefinierten Wert.

In addition, a method is proposed for performing an EMC measurement on a test object to be measured, with at least the following steps:

• a. Providing a test bench, comprising a platform and a platform-supporting substructure, wherein the test bench comprises at least one height adjustment device for selectively setting a ground clearance of the platform,
• b. Actuating the at least one height adjustment device for setting the ground clearance to a predefined value.

Here, the step of actuating the at least one height adjustment device may include actuating a first height adjustment device for height adjustment of the platform.

Alternatively or additionally, the step of actuating the at least one height adjustment device may comprise lowering the lower edge of the platform relative to an upper edge of a platform by means of a second height adjustment device. A possible actuation of the first and the second height adjustment devices can be independent and temporally separated from each other or simultaneously.

The invention will be explained in more detail using an exemplary embodiment with reference to the drawings. Show it:

1 : a test bench for EMC measurement according to the description,

2 : the test bench off 1 compared to a complete vehicle.

In 1 is a test stand in a side view and an associated plan view 10 for performing an EMC measurement on a test object to be measured 11 shown. The test bench 10 includes a platform 12 for receiving the test object to be tested 11 , These are on a top 12a the platform 12 Recordings 14 provided the examinee 11 support. In addition, the test bench includes 10 one the platform 12 supporting substructure 15 and two height adjustment devices 16 . 17 for selectively setting a ground clearance of the platform 12 ,

A first height adjustment device 16 the two height adjustment devices is for adjusting a height h _{2 of} the entire platform 12 formed by means of a lifting mechanism with height-adjustable legs. For this purpose, the first height adjustment device 16 for example in the substructure 15 be integrated. Alternatively, other lifting mechanisms are also possible, such as a scissor-type Lifting mechanism used, but they are not shown.

In addition, the test bench includes 10 a second height adjustment device 17 for lowering a lower edge 12b the platform 12 opposite one at the top 12a arranged upper edge of the platform 12 is trained.

In the illustrated embodiment, the platform comprises 12 an electrode element 18 which is the bottom edge 12b the platform 12 Are defined. In addition, the electrode element 18 designed plate-shaped and by means of the second height adjustment 17 spaced parallel to the upper edge or the upper side 12a the platform 12 towards the floor supporting the test stand 19 lowered to a height h ₁ . The electrode element 18 is as a section of the bottom of the entire platform 12 trained, however, can as well as the entire lowerable underside of the platform 12 form (not shown). For example, only the second height adjustment device 17 designed as a scissor-shaped lifting mechanism.

Optional and for the sake of clarity only in 2 shown, the electrode element 18 by means of an electrical low-impedance and at the same time flexible connection 21 with the upper edge or the upper side 12a the platform 12 be electrically connected. This can be achieved, for example, with one or more flat and flexible conductors.

Each of the two height adjustment devices 16 . 17 can be mechanically, electrically, pneumatically and / or hydraulically actuated.

To simplify the design of the test bench 10 To achieve, includes the platform 12 a pallet construction. In addition, the test bench 10 movably formed by on the platform supporting the platform 15 bikes 22 are arranged, which allows easy movement of the entire test bench 10 enable. Optional and therefore merely indicated, the platform 12 an integrated test bench drive system 23 to operate the test object 11 include, wherein the test bed drive system 23 has an EMC shield.

ab. ε₀ steht hierbei für die elektrische Feldkonstante des Vakuums und ε_r für die dielektrische Leitfähigkeit des Dielektrikums, also üblicherweise Luft. 2 shows the test bench 1 compared to a complete vehicle 30 to explain the physical relationships. An exemplary circuit 31 in the vehicle is governed by the parasitic capacitance C _Fzg between the metallic bottom usually used 19 and the vehicle 30 affected. This depends on the one hand on the base of the vehicle A _Fzg and its height h _Fzg on the metallic floor 19 according to

from. ε ₀ stands for the electric field constant of the vacuum and ε _r for the dielectric conductivity of the dielectric, ie usually air.

Basically, for the parasitic capacitance C _{Pst of} a test bench, the analogous relationship between the base area A _{Pst of} the test bench and the height h _{Pst of} the test bench above the floor slab is determined according to:

Due to the multi-part construction with a multi-part base and different associated heights h ₁ and h _{2 of} the test bench shown 10 In this case, the capacitance C _Pst results from the sum of all area and height elements of the test bench:

Both the base area A _{Fzg of} the vehicle 30 as well as the base area A _{Pst of} the test bench 10 are each to be understood as surfaces within a plane aligned parallel to the ground.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10049192 A1 [0003]
• DE 102012212886 A1 [0004]

Cited non-patent literature

• Standard CISPR25 [0002]

Claims (14)

Test bench for performing an EMC measurement on a test object to be measured, with a platform ( 12 ) for receiving the test object to be tested ( 11 ) and one the platform ( 12 ) supporting substructure ( 15 ), characterized in that the test bench ( 10 ) at least one height adjustment device ( 16 . 17 ) for selectively setting a ground clearance (h ₁ , h ₂ ) of the platform ( 12 ). Test stand according to claim 1, characterized in that a first height adjustment device ( 16 ) the at least one height adjustment device ( 16 . 17 ) for height adjustment of the platform ( 12 ) is trained. Test stand according to claim 2, characterized in that the first height adjustment device ( 16 ) a lifting mechanism for height adjustment of the platform ( 12 ), in particular a lifting mechanism with height-adjustable legs or a scissor-type lifting mechanism. Test stand according to at least one of claims 1 to 3, characterized in that the test bench ( 10 ) a second height adjustment device ( 17 ) the at least one height adjustment device ( 16 . 17 ) for lowering a lower edge ( 12b ) of the platform ( 12 ) opposite a top edge ( 12a ) of the platform ( 12 ) is trained. Test stand according to claim 4, characterized in that the platform ( 12 ) an electrode element ( 18 ) comprising the lower edge ( 12b ) of the platform ( 12 ) Are defined. Test stand according to claim 5, characterized in that the electrode element ( 18 ) is designed plate-shaped and by means of the second height adjustment device ( 17 ) spaced parallel to the top edge ( 12a ) of the platform ( 12 ) is lowered. Test stand according to at least one of claims 5 to 6, characterized in that the electrode element ( 18 ) by means of a low-impedance, flexible conductor ( 21 ) with the upper edge ( 12a ) of the platform ( 12 ) is electrically connected. Test stand according to at least one of claims 1 to 7, characterized in that the at least one height adjustment device ( 16 . 17 ) is mechanically, electrically, pneumatically and / or hydraulically actuated. Test stand according to at least one of claims 1 to 8, characterized in that the platform ( 12 ) comprises a pallet construction. Test stand according to at least one of claims 1 to 9, characterized in that the test bench ( 10 ) is designed mobile. Test stand according to at least one of claims 1 to 10, characterized in that the platform ( 12 ) an integrated test bed drive system ( 23 ) for operating the test piece ( 11 ), wherein the test bed drive system ( 23 ) includes an EMC shield. Method for performing an EMC measurement on a test object to be measured, with at least the following steps: a. Provision of a test bench ( 10 ), with a platform ( 12 ) and one the platform ( 12 ) supporting substructure ( 15 ), the test bench ( 10 ) at least one height adjustment device ( 16 . 17 ) for selectively setting a ground clearance (h ₁ , h ₂ ) of the platform ( 12 ), b. Actuating the at least one height adjustment device ( 16 . 17 ) for setting the ground clearance (h ₁ , h ₂ ) to a predefined value. A method according to claim 12, characterized in that the step of actuating the at least one height adjustment device ( 16 . 17 ) actuating a first height adjustment device ( 16 ) for height adjustment (h ₂ ) of the platform ( 12 ). Method according to one of claims 12 or 13, characterized in that the step of actuating the at least one height adjustment device ( 16 . 17 ) a lowering of the lower edge ( 12b ) of the platform ( 12 ) opposite a top edge ( 12a ) of the platform ( 12 ) by means of a second height adjustment device ( 17 ).

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