DE102010055512B4 - Drive system with devices to prevent electromagnetic interference - Google Patents

Abstract

Drive system with means for preventing electromagnetic interference, comprising: - at least one electric motor (2); - At least one Frequenzumrichteinrichtung (3) for converting DC voltage frequencies; At least one voltage supply device (4), and connecting lines (5) between the voltage supply device (4) and a housing (6) common to the electric motor (2) and the frequency converter device (3), characterized in that the devices each comprise at least one to a capacitive capacitor element (13, 16, 21, 22, 23, 24) which is arranged at least partially made of electrically and magnetically conductive material and which is connected to the housing (6) on each end of the conducting connecting line (11) ), wherein the capacitive capacitor element (13, 16, 21, 22, 23, 24) in each case each screen and lateral surface (10) end surrounding electrically conductive cylinder jacket piece (16) with the housing (6) is directly connected, so that a part of the capacitive capacitor element (13, 16, 21, 22, 23, 24), of the cylinder jacket piece (16) and another part is formed by an end piece of the shielding and lateral surface (10), the cylinder jacket piece (16), viewed in the longitudinal direction (11a) of the cylinder-like shielding and lateral surface (10), having a first end piece of the shielding and lateral surface (10). 10) surrounding portion (25) and a screen and mantle surface-free portion (26), wherein additionally the capacitive capacitor element (13, 16) in each case at least one on the end face (15) of the cylinder-like shield and lateral surface (10) arranged first A plate (21) made of an electrically conductive material and having a base extending perpendicularly to the longitudinal direction (11a) of the cylinder-like shielding and enveloping surface (10), and a second plate aligned parallel thereto and spaced from the first plate (21, 23) (22, 24) directly connected to the housing (6).

Description

The invention relates to a drive system with means for preventing electromagnetic interference in the presence of an electric motor, a Frequenzumrichteinrichtung for converting DC voltage, a voltage supply device and connecting lines between the power supply device and a housing common to the electric motor and the Frequenzumrichteinrichtung according to the preamble of claim 1.

The electric motor has a rotor and a stator surrounding it with a plurality of magnetic poles distributed around a motor axis and windings accommodated in cavities, and cooling passages through which a cooling medium can flow in the cavities.

Known electric motors, such as a synchronous motor, an asynchronous motor or a DC motor, comprise a stator having the winding and a rotor enclosed by the stator. To increase the power of the electric motor, it is already known that a so-called split tube is provided on the rotor facing the inner surfaces of the stator enclosing the rotor or on the inner surface of the stator laminated core, ie to arrange a circular cylindrical wall portion, which formed in the laminated core and grooves open to the rotor for receiving the portions or conductors of the stator winding to the machine gap between the stator and the rotor seals. A portion of each groove not occupied by the electrical conductors of the winding can, as in DE 10 2004 013 721 A1 shown, are used as a channel of a cooling channel system, which is traversed by a suitable, electrically non-conductive cooling medium.

The rotor having the winding and forming magnetic poles may be made of plastic, which contains a high proportion of an electrically non-conductive, but magnetically conductive filler.

Such electric motors often require a Frequenzumrichteinrichtung or a Frequenzkonvertereinrichtung between a power and voltage supply device and the electric motor.

A voltage and power supply device is often connected via voltage and power supply lines, optionally together with Kühlablauf- and supply lines for cooling the electric motor, and various components, such as a coil with a Frequenzumrichter- or frequency converter housing of a frequency converter or a frequency converter , The frequency converter is often housed in a different housing than the electric motor. With such a construction of at least one frequency converter, an electric motor, connecting lines and voltage and power supply lines, and a voltage and power source, parasitic capacitances generally occur. These parasitic capacitances and also inductances generate during switching operations of the frequency converter with high voltage-time changes dU / dt so-called leakage currents or common-mode currents.

Although a common housing for the frequency converter and the electric motor can reduce the susceptibility to electromagnetic waves for the drive system, however, it becomes clear at the latest when connecting the power and voltage supply lines for the necessary voltage source that in such emerging from the housing lines sheath currents and a galvanic connection between the lines and the housing exist. This is particularly evident when using high voltage and high current cables.

Therefore, sheathings of the lines are conventionally used by means of a shield and lateral surface, especially in high-voltage and high-current lines. Such screen and lateral surfaces are only one-sided, d. H. preferably earthed at one end of the cylinder-like surfaces. This undesirably leads to the reduction of the shielding of electromagnetic interference and to the impairment of the electromagnetic performance of the shield and lateral surfaces.

In the publication "EMC fault-proof design of electronic circuits" by Joachim Franz it is disclosed that by means of a coaxial cable, a shield arranged on one side to ground protects against capacitive and direct electromagnetic coupling. To reduce the current at low frequencies, a two-sided shield connection to ground is advantageous, for which purpose a capacitor can be connected to ground.

From the DE 10 2008 013 416 A1 For example, an arrangement with a generator and a transformer connected to the generator via at least one shielded conductor is known, wherein an electrically conductive envelope surrounds the conductor for shielding the conductor. Furthermore, means for shielding the generator and the transformer are provided.

The forming the generic term DE 44 42 867 C2 discloses a drive arrangement for a vehicle, in particular a road vehicle with an electric motor, an electronic circuit breaker connected to windings of the electric motor, the electronic circuit breakers are held on the electric motor, a control circuit controlling the circuit breaker and a cooling device whose coolant circuit the electric motor and held on it Circuit breaker cools.

From the DE 10 2008 030 338 A1 is an electric drive system, in particular a hybrid vehicle, known with a number of electrical power components and with a number of electrical power components and at least one connected to this supply cable, wherein the supply cable is cooled.

Thus, the object of the present invention is to provide a drive system with electromagnetic interference prevention devices which, when incoming and outgoing voltage and current lines are connected to a common housing for a frequency converter and an electric motor, has one Avoidance of electromagnetic interference.

This object is achieved according to the features of claim 1.

• – mindestens einen elektrischen Motor,
• – mindestens eine Frequenzumrichteinrichtung zum Umrichten von Gleichspannungsfrequenzen,
• – mindestens eine Spannungsversorgungseinrichtung,
• – Verbindungsleitungen zwischen der Spannungsversorgungseinrichtung und einem für den elektrischen Motor und die Frequenzumrichteinrichtung gemeinsamen Gehäuse,

umfasst, die Einrichtungen jeweils mindestens ein an eine Schirm- und Mantelfläche jeder stromführenden Verbindungsleitung endseitig angeordnetes kapazitiv wirkendes Kondensatorelement umfassen, welches mit dem Gehäuse verbunden ist. Diese Verbindung erfolgt direkt, also von der Schirm- und Mantelfläche zu dem Gehäuse. Eine derart kapazitiv mit dem Gehäuse verbundene Verbindungsleitung zur Führung von Strom ermöglicht eine Erhöhung des Abschirmeffektes der Schirm- und Mantelflächen, der nachweislich für einen erhöhten Frequenzbereich anwendbar ist.The central idea of the invention is that in a drive system with means for the prevention of electromagnetic interference, which

• At least one electric motor,
• At least one frequency converter device for converting DC voltage frequencies,
• At least one power supply device,
• Connecting lines between the voltage supply device and a housing common to the electric motor and the frequency converter device,

comprises, the devices each comprise at least one capacitive capacitor element arranged end-to-end on a shield and lateral surface of each current-carrying connecting line, which capacitor is connected to the housing. This connection is made directly, ie from the shield and lateral surface to the housing. Such a capacitive connected to the housing connection line for guiding current allows an increase of the shielding effect of the shield and lateral surfaces, which is demonstrably applicable for an increased frequency range.

According to the invention, the capacitive capacitor element comprises in each case one each screen and lateral surface, which surrounds at least one current-carrying connecting line in the manner of a cylinder, the end surrounding electrically conductive cylinder jacket piece, which is connected to the housing. That is, the cylinder block piece would be directly connected to the housing or optionally to a ground line, whereas the shield and lateral surface surrounding the connecting conductor cylinder-like is not connected to the housing or the ground. Between the cylinder jacket piece and the shield and lateral surface, a continuous cylinder jacket-shaped intermediate space without an electrically conductive connection between the shield and lateral surface and the cylinder jacket piece is arranged. Thus, a capacitive capacitor element is provided, of which the one part of the cylinder jacket piece and the other part forms an end of the shield and lateral surface. In between is - as already mentioned - arranged a gap with electrical insulation material.

According to the invention, the cylinder jacket piece viewed in the longitudinal direction of the cylinder-like shielding and lateral surface has a first section which surrounds an end piece of the shielding and lateral surface and a second section free of screen and jacket surface. This means that viewed in the longitudinal direction, the cylinder jacket piece extends beyond the end piece of the shielding and lateral surface and thus can be electrically and mechanically connected to the housing, for example, without parts of the shielding and lateral surface touching the housing.

In addition, the capacitive capacitor element can each have at least one arranged on the end face of the cylinder-like shield and lateral surface first plate, which consists of electrically conductive material, and whose base surface extends perpendicular to the longitudinal direction of the cylinder-like shield and lateral surface, and one of the first Plate spaced parallel aligned second plate, which is connected to the housing. Such construction of a first and second plate, which preferably have the same base area, but may also have different base areas, also leads to the formation of a capacitor, wherein a gap between the two plates should again be designed connectionless in terms of electrical and magnetic conductivity. This leads again to a capacitive coupling of the shield and lateral surface to the housing or directly to a line or an element which is connected to the ground, without the shield and lateral surface is connected directly to the housing or the ground. Advantageously, as a result, as well as in the use of a cylinder jacket piece be achieved that no parasitic capacitances occur, as would occur when using a discrete capacitor component connector between the shield and lateral surface and the housing. Rather, there is a large capacitive capacitive arrangement capacitor.

The first and second plates may have a circular or a quadrangular or other polygonal base.

With such a capacitive connection of the shield and lateral surfaces to one or more housings, which is preferably metallic and is electrically as well as magnetically conductive, galvanic separation between the shield and lateral surfaces as well as the housing can be achieved without compromising the performance of the shielding properties of the shield. and lateral surfaces with regard to electromagnetic interference.

With additional filter elements, such as discrete capacitors and inductors, electromagnetic properties of the entire drive system can be adapted to the respective required use of the drive system. In particular, if electromagnetic interference during the transport of currents in the connecting lines to be shielded with lower frequencies, additionally arranged discrete capacitors prove to be around the area capacitive capacitor elements around advantageous. Such capacitive expansion with discrete capacitors is not limited to capacitors only. Rather, any component can be used for a filter application to create a filter connection with respect to the housing.

At least part of the capacitive-effect capacitor element is connected to a ground line to ensure a controlled common-mode current flow and thus to avoid electromagnetic interference.

The capacitive capacitor element according to the invention is at least partially constructed of electrically or magnetically conductive material.

The shield and lateral surface consists at least partially of electrically and magnetically conductive material.

The shielding and lateral surface may be designed as a hydraulic hose with oil arranged between the shielding and lateral surface and the electrical connection line and optionally at least one cooling line containing a coolant.

Further advantageous embodiments will become apparent according to the subclaims.

Advantages and expediencies can be found in the following description in conjunction with the drawing. Hereby show:

1 In a first schematic representation of the drive system according to the invention;

2 In a schematic representation of the basic principle of the invention;

3a In a schematic representation of a connecting line in a drive system according to a first embodiment of the invention;

3b In a schematic circuit diagram, the connection line in the drive system according to the first embodiment of the invention;

4 In a simple schematic representation, another basic principle of the present invention;

5a - 5c Various forms of implementation according to further embodiments of the invention; and

6 In a diagram the effect of the present invention on the shielding effect.

In 1 is shown in a schematic representation of a drive system according to the present invention. This drive system 1 has an electric motor 2 and a frequency converter 3 and a power supply device 4 on. Between the voltage supply device 4 and a common housing 6 , which is for the frequency converter 3 and the electric motor 2 and possibly other components, such as a heat sink is provided, connecting lines 5 arranged.

The connection lines 5 may also have cooling lines, which have a supply of the heat sink with coolant to the task.

The connecting lines are sheathed by means of a hydraulic hose metallic at least partially electrically conductive surface.

The connection lines 5 are - as in 2 as an internal live conductor 11 that extends longitudinally 11a the connecting line extends, and a cylinder-like arranged around screen and lateral surface 10 educated.

The shield and lateral surface 10 is by means of a ground conductor 12 connected to the mass. Likewise, by means of a connecting line 14 According to the invention, the screen and lateral surface end with a styletically illustrated capacitive connection 13 connected to the mass.

In 3a shows a possible realization of the capacitive capacitor element according to a first embodiment of the invention. The shield and lateral surface 10 which the electrical conductor 11 surrounds, is end with a tail 15 or an end face 15 in a cylinder block piece 16 arranged, which opposite the screen and lateral surface 10 by means of a gap 16a is spaced. In this way, a capacitor-like effect between the cylinder jacket section 16 and the end area 15 the shield and lateral surface 10 receive.

This is clarified again in 3b in which the capacitive effect is shown schematically with switching elements. This illustration shows that the shield and lateral surface 10 by means of capacitors 16a and 16b , which is representative of the cylinder block piece 16 and the gap 16a as well as the tail 15 are shown with a mass 17 are connected. This mass 17 can also with the case 6 be connected conductively connected to the drive system.

In 4 In another simplified circuit, another basic principle is added to that in 2 shown basic principle.

The in 4 reproduced representation can clearly be seen that the shield and lateral surface 10 in addition to a connection arranged on one side end with a mass 12 and a connection on the other side end with the ground 17 via a capacitive capacitor element 13 additionally a discrete capacitor 19 in the pipe 18 is arranged, which is parallel to the capacitive capacitor element 13 present and also with a mass 20 connected is. This capacitor 19 can be arranged in many ways. That is, any component or a plurality of components that have a condenser-like filtering action can be used therefor.

In 5a . 5b and 5c Further embodiments of the drive system according to the invention with connecting lines present therein are shown. The screen and lateral surfaces reproduced at the end 10 show in 5a frontally at the end region 15 a first plate 21 on, parallel to a second plate 22 with identical or other base, in this case circular, spaced parallel to each other.

Alternatively, the bases of the capacitive capacitor element according to 5b as first plate 23 and second plate 24 quadrangular, preferably square.

In 5c is again the in 3a reproduced embodiment shown. Here it can be clearly seen that the shield and lateral surface 10 in a first section 25 Tail-like within the cylinder shell piece 16 lies and in a second section 26 is not arranged. This allows a connection of the cylinder block piece 16 to the housing or the ground, without the shield and lateral surface 10 In direct contact herewith occurs, thus a capacitive connection of the shield and lateral surface is obtained to the housing or the mass.

In 6 is a diagram showing the shielding effect in its change with respect to the frequency range of the frequencies of the guided in the connecting lines currents.

As can be seen from this illustration, here is the worse and better shielding effect of the shield and lateral surface as a function of one on the abscissa 28 plotted frequency of the guided current reproduced within the connecting line.

This representation can be clearly seen that according to reference numerals 29 at a connection of the tail 1 a connection line and a shield and lateral surface with the housing or the mass can be shielded solely by discrete capacitors electromagnetic interference from currents at high frequencies. There is thus a drop in the shielding effect only at high frequencies on the level 32 instead of.

According to the reference numeral 30 is a shift according to area 33 the curve in the direction of the lower frequencies in the use of capacitive capacitive elements with areal education, as shown in the 5a . 5b and 5c is shown reproduced.

Another shift of the curve is according to reference numerals 31 at a connection of the shield and lateral surface with the capacitive capacitor elements in areal design according to 5a . 5b and 5c obtained together with the arrangement of discrete capacitors. In summary, this results in a gain or an improvement in the shielding effect, as represented by the color-coded area between the curves.

All disclosed in the application documents features are claimed as essential to the invention, provided they are new individually or in combination over the prior art.

LIST OF REFERENCE NUMBERS

1

drive system

2

Electric engine

3

Frequenzumrichteinrichtung

4

Power supply means

5

interconnectors

6

casing

10

Screen and lateral surface

11

Electrical conductor

12

ground conductor

13

Capacitive connection

14

connecting line

15

tail

16

Cylinder jacket piece

16a

gap

17

Dimensions

18

management

19

capacitor

20

Dimensions

21

First plate

22

Second plate

23

First plate

24

Second plate

25

first section

26

second part

28

abscissa

29

Curve

30

Curve

31

Curve

32

level

33

area

Claims (7)

Drive system with means for preventing electromagnetic interference, comprising: - at least one electric motor ( 2 ); At least one frequency converter device ( 3 ) for converting DC frequencies; At least one power supply device ( 4 ), and - connecting lines ( 5 ) between the power supply device ( 4 ) and one for the electric motor ( 2 ) and the frequency converter ( 3 ) common housing ( 6 ), characterized in that the devices each have at least one shielding and jacket surface (11) which is at least partly made of electrically and magnetically conductive material ( 10 ) of each live connecting line ( 11 ) end-mounted, capacitive capacitor element ( 13 . 16 . 21 . 22 . 23 . 24 ), which with the housing ( 6 ), wherein the capacitive capacitor element ( 13 . 16 . 21 . 22 . 23 . 24 ) each one screen and lateral surface ( 10 ) end-surrounding electrically conductive cylinder jacket piece ( 16 ) connected to the housing ( 6 ) is directly connected, so that a part of the capacitive capacitor element ( 13 . 16 . 21 . 22 . 23 . 24 ), of the cylinder block piece ( 16 ) and another part of an end piece of the shield and lateral surface ( 10 ) is formed, wherein the cylinder jacket piece ( 16 ) - longitudinal ( 11a ) of the cylinder-like shielding and lateral surface ( 10 ), a first one end of the shield and lateral surface ( 10 ) surrounding section ( 25 ) and a screen and mantle free section ( 26 ), wherein additionally the capacitive capacitor element ( 13 . 16 ) at least one on the front side ( 15 ) of the cylinder-like shielding and lateral surface ( 10 ) arranged first plate ( 21 ), which consists of electrically conductive material and whose base is perpendicular to the longitudinal direction ( 11a ) of the cylinder-like shielding and lateral surface ( 10 ) and one of the first plate ( 21 . 23 ) spaced parallel thereto aligned second plate ( 22 . 24 ), which are connected to the housing ( 6 ) is directly connected. Drive system according to claim 1, characterized in that each screen and lateral surface ( 10 ) at least one current-carrying conductor ( 11 ) surrounds like a cylinder. Drive system according to claim 1 or 2, characterized in that between the cylinder jacket piece ( 16 ) and the shield and lateral surface ( 10 ) a continuous cylinder jacket-shaped intermediate space ( 16a ) without an electrically conductive connection between the shielding and lateral surface ( 10 ) and the cylinder block piece ( 16 ) is arranged. Drive system according to at least one of the preceding claims, characterized in that the first and the second plate ( 21 . 22 . 23 . 24 ) have a circular, oval or a quadrangular or other polygonal base. Drive system according to one of the preceding claims, characterized in that at least one filter element in addition to the capacitive capacitor element ( 13 . 16 . 21 . 22 . 23 . 24 ) between an end piece ( 15 ) of the cylinder-like shielding and lateral surface ( 10 ) and the housing ( 6 ) or a ground line ( 20 ) is arranged. Drive system according to one of the preceding claims, characterized in that the capacitive capacitor element ( 13 ; 16 ; 21 . 22 ; 23 . 24 ) consists at least partially of electrically and magnetically conductive material. Drive system according to one of the preceding claims, characterized in that the shield and lateral surface ( 10 ) as a hydraulic hose with between the shield and lateral surface ( 10 ) and the electrical conductor ( 11 ) arranged oil, as well as with at least one refrigerant containing a cooling line is formed.

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