CN111746442A - HV onboard power grid system for a vehicle - Google Patents

Abstract

HV onboard electrical system of a vehicle. The HV onboard power supply system according to the invention has a conductor arrangement with at least (2 n + 1) ribbon cables. n is a natural number of 1 or more. It is specified that the n ribbon cables are of a first cable type and the n +1 ribbon cables are of a second cable type. These (2 n + 1) strip cables are arranged overlappingly so that the strip cables of the first cable type and the second cable type are alternately laid on top of each other. The ribbon cables of the second cable type are respectively arranged outside. Thus, each ribbon cable of the first cable type is located between two ribbon cables of the second cable type. The term cable type refers to a cable connected to the positive or negative pole of an electrical HV energy source, wherein either a first cable type is connected to the positive pole of the HV energy storage of the HV on-board electrical system and a second cable type is connected to the negative pole, or the first cable type is connected to the negative pole of the HV energy source and the second cable type is connected to the positive pole.

Description

HV on-board grid system for vehicles

technical field

The present invention relates to an HV on-board power grid system of a vehicle.

Background technique

High-voltage (HV) on-board electrical systems of vehicles with hybrid or electric drives operate with high DC voltages, often in the range between 60V and a few kV. Since the electrical power of the HV components can be in the range of several kilowatts, high currents are conducted on the HV cables between the electrical accumulator and these components. These currents induce a magnetic field that is directly proportional to the strength of the current. Furthermore, the area stretched between the output and return conductors is decisive for the strength and realization of these magnetic fields.

In order to comply with personnel protection requirements, the emission of these magnetic fields must be shielded or otherwise reduced. For reasons of personal protection, the cables of the HV on-board power supply should be avoided from being laid in the interior space of the vehicle. Disadvantageously, the individual shielding of these cables is only a conditional approach to low-frequency magnetic fields, which is expensive and also entails high costs. It is also disadvantageous in this context that when laying the individual cables, an indeterminate distance is partly formed between the output and return conductors, which can lead to an enhancement of the magnetic field emission.

This is due in particular to the fact that high-current cables according to the prior art consist of joined filaments or solid cables consist of an electrically conductive material, which in each case have a cable shield as a covering, if necessary. These flexible cables can hardly be automatically routed in vehicles, and can hardly be automatically launched in vehicles due to the cable's internal configuration, weight and geometry, and flexibility. Consequently, these conventional flexible high-current cables must be expensive and expensive to run with a large number of fixtures.

In DE 10 2015 118 921 A1, a multi-voltage on-board electrical system of a motor vehicle is described, in which several on-board electrical systems (including also the HV on-board electrical system) are connected by means of several ribbon cables. In this case, according to the invention, the ribbon cables are arranged one on top of the other, so that a common return conductor is arranged between at least two output conductors of two different onboard electrical systems. Disadvantageously, since the output conductors carry different current strengths, this arrangement can only insufficiently compensate for the emission of electromagnetic fields.

SUMMARY OF THE INVENTION

The present invention is now based on the task of proposing an HV on-board electrical system of a vehicle, the conductor arrangement of which causes only a very small emission of electromagnetic radiation, has a very small inductive coating and is also simple and safe ground and cost-effective to lay.

The HV on-board electrical system according to the present invention has at least (2n+1) ribbon cables. Here, n is a natural number greater than/equal to 1 (n={1, 2, 3…}). Of the (2n+1) ribbon cables, it is specified that n ribbon cables are of the first cable type and n+1 ribbon cables are of the second cable type.

Here, the (2n+1) ribbon cables are arranged overlappingly, so that the ribbon cables of the first cable type and the second cable type alternately overlap each other. Here, the ribbon cables of the second cable type are respectively arranged on the outside. Thus, each ribbon cable of the first cable type is between two ribbon cables of the second cable type.

For the purposes of this application, the term cable type refers to a cable that is connected to the positive or negative pole of the vehicle's electrical HV energy source (eg HV battery pack, fuel cell or buffer store), wherein either the first cable type is connected to the HV Either the positive pole of the HV energy source of the on-board electrical system is connected and the second cable type is connected to the negative pole of the HV energy source of the HV on-board electrical system, or the first cable type is connected to the negative pole of the HV energy source of the HV on-board electrical system and the second cable type is connected to the negative pole of the HV energy source of the HV on-board electrical system The cable type is connected to the positive pole of the HV energy source of the HV onboard electrical system. To clarify for clarity of explanation: The term cable type does not refer to the geometrical design or material of the cable, but as mentioned only to whether the cable is connected to the positive or negative terminal of the HV energy source Case.

Thus, the ribbon cables arranged in a stack form a cable wrap having a cross-sectional area as rectangular as possible. For the purposes of this application, a ribbon cable refers to a cable having as rectangular a cross-section as possible. Here, the ratio of height to width is preferably in the range between 1:1 and 1:20, more preferably in the range between 1:3 and 1:20, and particularly preferably in the range between 1:5 and 1:20. range between 1:15. Here, the specific ratio of height to width depends on different factors, in particular the number of ribbon cables in the conductor arrangement.

In this case, the ribbon cables arranged on top of each other with their electrically insulating coverings lie directly on top of each other. However, it is also possible to additionally introduce spacer layers, which preferably likewise consist of an electrically insulating material.

The invention is suitable for use in motor vehicles, in particular with hybrid or electric drives, but can also be used in other vehicles, such as trucks, aircraft, ships or rail vehicles. The invention cannot be applied in motor vehicles or in on-board electrical systems in which the body constitutes the return current path.

Advantageously, with the HV on-board electrical system according to the invention, the emission of electromagnetic radiation can be significantly reduced with simple means, so that expensive shielding of cables can be dispensed with.

Also advantageously, ribbon cables of different polarities act like plate capacitors and thus can store electrical energy. Advantageously, this makes it possible (additionally) to stabilize the HV onboard electrical system, since the conductor arrangement forms a definable energy buffer.

Another important advantage resides in the fact that filter elements for ensuring electromagnetic compatibility (EMV) can be reduced due to the storage capacity of the ribbon cable. With strip conductors, capacitances that can be defined with sufficient precision are provided. These capacitors can help resist differential-mode (Differential-Mode) and common-mode (Common-Mode) interference and are considered when designing EMV filters. Advantageously, this saves cost and installation space for the filter element.

It is also advantageously possible to save energy by means of the strip-shaped and parallel-oriented conductors, since the cable losses are lower.

Another important advantage of the invention resides in the fact that conductors with the same potential are arranged outside the conductor arrangement. In this way, the risk of a person accidentally touching conductors of different potentials can be reduced to a minimum, which amounts to a short circuit and a possible danger to life in the HV on-board electrical system.

However, on vehicle bodies or other conductive components, short circuits may also form when cables of different potentials with damaged insulation touch them. This risk can also be minimized by arranging strip conductors with the same potential outside the conductor arrangement. Advantageously, this can improve personnel protection in the same way as article protection (facility protection).

A cable wrap consisting of overlapping ribbon cables is also significantly more rigid and more self-stabilizing than the (flexible) round cables used according to the prior art, whereby the safety during cable routing can be significantly increased. degree of automation. Furthermore, far fewer securing means are required to secure the cable wrap. In this way, production costs can be advantageously reduced.

In a preferred solution, the conductor arrangement further has at least one ribbon cable of a third cable type. Here, the third cable type can be ground, body potential or also an equipotential cable. Here, it is easily understood that a plurality of ribbon cables can also be present in the stacked conductor arrangement, the ribbon cables being selected from ground, body potential or equipotential cables.

Here, preferably, a ribbon cable of the third cable type is arranged between the output and return conductors within the stacked conductor arrangement. Advantageously, by integrating at least one ribbon cable of a third cable type in the conductor arrangement, a targeted reduction of the common mode current can be achieved or an additional defined common mode capacitance can be provided. Since the ground cables, body potential cables and/or equipotential cables do not have to be routed separately, the degree of automation in routing the cables can also be increased.

In a particularly preferred configuration, the conductor arrangement is designed symmetrically with respect to a line of symmetry, which is parallel to the long side of the ribbon cable, and in the case of an odd number of ribbon cables in the conductor arrangement The lower middle of the ribbon cable or the middle of the two middle ribbon cables in the case of an even number of ribbon cables in the conductor arrangement. Advantageous in this homogeneous arrangement is a very good digestion of the magnetic field of the ribbon cable.

The inductive coating of the cables is likewise significantly reduced compared to simple strip conductors and double cables, as a result of the mutual compensation of the magnetic fields, while respecting the proposed type of symmetry and stacking.

In a preferred configuration of the HV onboard electrical system, the outer ribbon cables of the second cable type are wider than the ribbon cables of the first cable type arranged in between. Here, the width of the outer strip conductors, ie the uppermost and the lowermost strip conductors, is preferably 105% to 120% of the width of the strip conductors located therebetween. Advantageously, this further minimizes the emission of electromagnetic radiation and also improves the touch protection, since the inner conductors are better encapsulated and can thus hardly be touched inadvertently.

In another preferred design solution, when the number of overlapping ribbon cables is five or more, the widths of these ribbon cables are stepped from the inside to the outside. This means that each conductor is preferably 5% to 20% wider than the respective inwardly adjacent ribbon cable. Advantageously, with this measure, the emission of electromagnetic radiation due to the conductor arrangement can also be reduced.

In another preferred design solution, the sum of cable cross-sectional areas of all ribbon cables of the first cable type is as much as possible equal to the sum of all cable cross-sectional areas of all ribbon cables of the second cable type and. Advantageously, this facilitates the dissolution of the magnetic fields of both cable types and this further reduces the emission of electromagnetic radiation.

In a particularly preferred design, the ribbon cable of the first cable type is the output cable (connected to the positive pole of the HV energy source) and the ribbon cable of the second cable type is the return cable (ie connected to the negative terminal of the HV energy source). Advantageously, this enables the potential encapsulation inside the conductor arrangement, which is very advantageous for the safety of the HV on-board electrical system.

In a further preferred configuration, the onboard electrical system has an insulation monitor. The insulation monitor checks the HV on-board electrical system with regard to insulation faults by periodic high-ohmic connection of the positive and negative cables to the check voltage and simultaneous measurement and analysis of the fault current. Advantageously, the conductor arrangement according to the invention can improve the probability of detection of insulation faults by the insulation monitor, because since the capacitance of the conductor arrangement is known (compared to the capacitance of the conductor arrangement according to the prior art which can only be estimated in advance) it is possible to A more precise adjustment of the trip limit of the insulation monitor is achieved. In some cases, the insulation monitor can also advantageously be constructed more simply.

In another preferred design, at least one plug and/or at least one coupler of the cable connection has touch protection. The touch protection is an insulating covering in the area of the plug or coupler of the HV cable, which protects against touching during the establishment or release of the plug connection. Particularly preferably, several or all plug-in connections of the HV onboard electrical system are touch-protected. Advantageously, this can further improve personnel protection as well as item protection.

In a further preferred configuration, the HV battery pack of the HV onboard electrical system has switchable contacts for positive and negative poles. These switchable contacts can then be switched when there is an indication of a dangerous situation, so that the HV on-board electrical system is not charged with voltage or only with a voltage that is not dangerous. Signs of a dangerous situation can be, for example, the triggering of an airbag or seat belt tensioner, a high deflection of an acceleration sensor or also an accident detection by means of a vehicle camera. Advantageously, this can reduce the dangerous potential from the HV battery pack in the event of an accident.

In another preferred design solution of the present invention, the HV on-board power system has at least one equipotential cable, and particularly preferably, all HV components of the HV on-board power system have equipotential cables. Here, these equipotential cables provide a low-ohmic connection of the HV components. Advantageously, the safety of the HV onboard electrical system can also be further improved with this measure, since potential differences between these components can be prevented and a potentially life-threatening potential equalization can be ruled out when these components are touched.

Also preferably, a complete potential separation of the device region from the high voltage and from the low voltage is achieved. In this context, voltage converters in power electronics are galvanically separated. Advantageously, this measure also supports the protection of persons and objects.

In another preferred design solution, the HV on-board power system has an HV interlock (Interlock). This HV interlock monitors for loose plug connections when the high voltage grid is switched on. The loosening of the plug-in connection in the HV on-board electrical system can be very dangerous. Thus, the HV interlock switches the HV onboard electrical system to no voltage when it is determined that a high voltage connection is released. With this measure, the protection of persons and objects can also be further improved.

In a particularly preferred design solution of the present invention, the HV on-board power system has an output cable, and the output cable is arranged between the two return cables. Here, the sum of the areas of the cable cross-sections of the two return cables corresponds to the area of the cable cross-sections of the output cable. Here, the two return cables are preferably designed to be 5% to 20% wider than the output cable, so that the return cables extend beyond the output cable located between them on both sides. This embodiment is particularly well suited for passenger vehicles with an electric drive and is advantageously a good compromise with regard to electromagnetic compatibility, energy density, manufacturing costs and layability in the vehicle.

Another aspect of the invention is the use of the conductor arrangement according to the invention in electrical energy transmission installations, such as energy technology installations and transmission lines. In this case, the above-mentioned advantages of the invention also come into play, in particular the excellent electromagnetic compatibility.

Further preferred embodiments of the invention result from the remaining features mentioned in the dependent claims.

The different embodiments of the invention mentioned in the present application can be advantageously combined with one another, provided that they are not explained otherwise in individual cases.

Description of drawings

Subsequently, the invention is explained in the exemplary embodiments with reference to the associated drawings. in:

1 shows a cross-sectional view of a conductor arrangement of an HV on-board electrical system according to the invention;

Figure 2 shows a side view of the conductor arrangement of the HV on-board electrical system according to the invention;

Figure 3 shows a cross-sectional view of the conductor arrangement with the drawn electric field lines of the electric field;

Figure 4 shows a cross-sectional view of the conductor arrangement with the drawn magnetic field lines of the magnetic field;

Figure 5 shows a side view of a conductor arrangement of a plurality of strip conductors;

Figure 6 shows a cross-sectional view of a conductor arrangement with equipotential cables;

Figure 7 shows a side view of a conductor arrangement with equipotential cables; and

Figure 8 shows a side view of a conductor arrangement with a ground cable.

Detailed ways

FIG. 1 shows a cross-sectional view of a conductor arrangement 1 of an HV on-board electrical system according to the invention, which conductor arrangement has three ribbon cables. The conductor arrangement 1 has an output cable 31 arranged in the middle and two return cables 21 , 22 located below and above the output cable 31 . In the middle of the output cables 31, the line of symmetry 4 of the conductor arrangement 1 runs parallel to the long sides of these ribbon cables.

Here, the cross-sectional area of the output cable 31 is equal to the sum of the cross-sectional areas of the two return cables 21 , 22 . It can be seen well that the overall width of the two return cables 21 , 22 is made 10% wider than the output cable 31 , thereby improving the electromagnetic compatibility.

By arranging the return cables 21 , 22 on the outside of the conductor arrangement 1 , in conjunction with the wider implementation of the return cables 21 , 22 , personnel protection can be significantly improved, since the output cable 21 is almost completely encapsulated by the return cables 21 , 22 and So there is almost no surface to touch.

FIG. 2 shows a side view of the conductor arrangement 1 from FIG. 1 . Here, too, the stacked arrangement of the output cable 31 and the two return cables 21 , 22 can be seen well.

FIG. 3 shows the electric field lines 5 of the electric field (E field) of the conductor arrangement 1 . Here, the cables configured as ribbon cables, ie the output cable 31 and the return cables 21 , 22 act like a plate capacitor, which leads to the shown electric field lines of the E field.

Figure 4 shows the magnetic field lines 6 with the magnetic field (H field) of the output cable 31 and the return conductors 21, 22 through which current flows. Due to the different directions of current flow in the output cable 31 and the return cables 21, 22, the magnetic field between the output cable 31 and the return cables 21, 22 is enhanced. To the outside, however, the magnetic field is significantly reduced by this stacked arrangement.

Figure 5 shows a side view of the conductor arrangement 11 with seven ribbon cables. Three of the ribbon cables are output cables 31 , 32 , 33 , and the four ribbon cables are return cables 21 , 22 , 23 , 24 . In this design scheme, the output cables 31, 32, 33 and the return cables 21, 22, and 23 are also alternately arranged, so that there is always one output cable 31, 32, 33 and the two return cables 21, 21, 22, 23, 24 are adjacent. Here, the two return cables 21 , 24 form the outer closure, which enclose the ribbon cable arranged in between and are excellent touch protection.

In this configuration, the emission of electromagnetic radiation is also significantly reduced compared to cables according to the prior art. The advantage of this conductor arrangement compared to the embodiments according to FIGS. 1 to 4 is, in particular, a higher energy density.

FIG. 6 shows a cross-sectional view of the conductor arrangement 12 with two return cables 21 , 22 and one output cable 31 . Between the return cable 21 and the output cable 31 an equipotential cable 7 is arranged which connects the components of the HV onboard electrical system to each other in order to ensure touch protection. Advantageously, by integrating the equipotential cables 7 into the conductor arrangement 12, the equipotential cables 7 do not have to be laid separately. In the stacked conductor arrangement 12, the output cables 31, the return cables 21, 22 and the equipotential cables 7 have the same width.

FIG. 7 shows the conductor arrangement 12 of FIG. 6 in a side view.

FIG. 8 shows a side view of the conductor arrangement 13 consisting of three return cables 21 , 22 , 23 , two output cables 31 , 32 and one between the return cable 22 and the output cable 31 Ground cable 8 is formed.

List of reference signs

1 Conductor set with three ribbon cables

11 Conductor set with seven ribbon cables

12 Conductor arrangements with equipotential cables

13 Conductor set with grounding cable

21 Return cable

22 Return cable

23 Return cable

24 Return cable

31 Output cable

32 output cable

33 Output cable

4 lines of symmetry

5 Electric field lines of the E field

6 Magnetic field lines of the H field

7 Equipotential cable

8 Ground cable

Claims (15)

1. The HV on-board power grid system of the vehicle, the HV on-board power grid system has a conductor arrangement (1, 11, 12, 13) having at least (2n+1) ribbon cables (n={1, 2, 3...}), wherein among the (2n+1) ribbon cables, it is specified that n ribbon cables are the first cable type and n+1 ribbon cables are the second cable type , and the (2n+1) ribbon cables are arranged overlappingly, so that the ribbon cables of the first cable type and the second cable type are arranged alternately overlapping, wherein the second cable type Ribbon cables of cable type are respectively arranged on the outside. 2. The HV on-board power grid system of claim 1, wherein the outer ribbon cables of the second cable type are wider than ribbon cables arranged therebetween. 3. HV on-board electrical system according to any one of the preceding claims, characterized in that the conductor arrangement (12, 13) has at least one ribbon cable of a third cable type. 4. The HV on-board power grid system according to claim 3, wherein the third cable type is a ground cable (8), a body potential or an equipotential cable (7). 5. The HV onboard power grid system of any one of the preceding claims, wherein the sum of the cable cross-sectional areas of all ribbon cables of the first cable type is equal to the first cable The sum of all cable cross-sectional areas of all ribbon cables of the type. 6. The HV on-board electrical system according to any one of the preceding claims, characterized in that the conductor arrangements (1, 11, 12, 13) are symmetrical in cross-sectional area, wherein the line of symmetry (4) is in the When the number of the ribbon cables in the conductor device (1, 11, 12, 13) is odd, it is located in the middle of the middle ribbon cable. 7. The HV on-board electrical system according to any of the preceding claims, characterized in that the ribbon cable of the first cable type is an output cable (31, 32, 33) and the second cable type Cable type ribbon cables are return cables (21, 22, 23, 24). 8. The HV on-board power grid system according to any one of the preceding claims, wherein the ratio of height to width of the ribbon cable is between 1:3 and 1:20. 9 . The HV on-board electrical system according to claim 1 , wherein the HV on-board electrical system has an insulation monitor. 10 . 10 . The HV on-board electrical system according to claim 1 , wherein at least one plug and/or at least one coupler of the HV on-board electrical system has touch protection. 11 . 11. The HV on-board electrical system according to any one of the preceding claims, characterized in that the HV on-board electrical system has an HV energy source with switchable contacts for positive and negative poles . 12. The HV on-board electrical system according to any one of the preceding claims, characterized in that the HV on-board electrical system has at least one equipotential cable. 13. The HV on-board power grid system according to any one of the preceding claims, wherein the ribbon cable of the first cable type is arranged on two ribbon cables of the second cable type between. 14. A vehicle having an HV on-board electrical system according to any preceding claim. 15. Use of the conductor arrangement of an HV on-board electrical system according to any of the preceding claims in energy technology installations or energy technology transmission routes.

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