Traction network in an electric or hybrid vehicle

Abstract

Traction network (1) in an electric or hybrid vehicle, comprising a first and a second traction line (2, 4), each having an insulating sheath (3, 5), wherein the first traction line (2) is connected to a positive terminal of a high-voltage battery and the second traction line (4) is connected to a negative terminal of the high-voltage battery, wherein at least one closed conductor loop (6) with at least one turn is arranged on the traction lines (2, 4), wherein the traction lines (2, 4) and the at least one conductor loop (6) are electrically insulated, wherein the conductor loop (6) rests at least partially on the traction lines (2, 4) or the conductor loop (6) is at least partially integrated into the sheath (3, 5) of the traction lines (2, 4), wherein at least two conductor loops (6) are arranged on the traction lines (2, 4).

Description

[0001] The invention relates to a traction network in an electric or hybrid vehicle.

[0002] Such a traction system typically consists of a high-voltage source and an inverter connected by traction cables. The high-voltage source is, for example, a high-voltage battery. Current ripples occur on the traction cables, particularly due to switching operations of the inverter, generating time-varying magnetic fields that are relatively strong due to the overall high current levels. These magnetic fields can lead to electromagnetic interference (EMI). Another problem is the induction of currents into the vehicle body, which heats up as a result. Furthermore, this can generate unwanted noise due to magnetostriction, the piezoelectric effect, or force.

[0003] Magnetic fields can be redirected using permeable materials, but these are expensive and quickly reach saturation. Other measures include electrical shielding or reducing the distance between the traction cables. Shielding plates are problematic for manufacturing and can also negatively impact the vehicle's EMC performance due to resonance effects. The distance from the traction cables cannot be arbitrarily small due to production constraints and the insulation materials.

[0004] From DE 10 2005 062 714 A1, a cable with at least one first and one second conductor is known, wherein the first conductor and the second conductor each comprise a plurality of insulated individual cables. Several individual cables of the first conductor and / or several individual cables of the second conductor are electrically connected to one another in a starting and / or ending section of the cable. At least one individual cable of the first conductor is arranged at least sectionally directly adjacent to and substantially parallel with at least one individual cable of the second conductor and forms a group of individual cables with it. The first and second conductors of the cable can be used as traction lines in an electric or hybrid vehicle.

[0005] From DE 100 32 367 A1, a device for locally reducing the low-frequency magnetic field generated by a current-carrying conductor is known, which has at least one short-circuit loop and a section of the short-circuit loop is arranged near the current-carrying conductor and at least substantially parallel to it. The current is a usable alternating current.

[0006] From DE 11 2015 006 677 T5 a line with noise filter is known, comprising a line body, a coil-shaped inductor surrounding the line body, and a capacitor arranged between the line body and the inductor, such that an LC resonant circuit is formed.

[0007] From US patent 2009 / 0133925 A1, a cable assembly, in particular a high-voltage cable assembly for a motor vehicle, is known, comprising at least one electrical cable that includes an electrical conductor and a surrounding shield. The cable assembly further includes a device for routing the cable and for connecting the cable shield, wherein the device comprises a feedthrough element through which a cable end passes and a pull-in sleeve. The pull-in sleeve comprises a shaft and a head that is wider than the shaft, wherein the pull-in sleeve is inserted with the shaft between the electrical conductor and the shield and held by the head on the feedthrough element.

[0008] The invention is based on the technical problem of creating a traction network in which the problems caused by unusable current ripples on the traction lines are reduced using simple means.

[0009] The solution to the technical problem is achieved by a traction network with the features of claim 1. Further advantageous embodiments of the invention are set out in the dependent claims.

[0010] In an electric or hybrid vehicle, the traction network comprises a first traction cable and a second traction cable, each with an insulating sheath. The first traction cable is connected to the positive terminal and the second traction cable to the negative terminal of a high-voltage battery. At least one closed conductor loop with at least one winding is arranged on the traction cables, with the traction cables and the at least one conductor loop being electrically insulated. The basic principle is that the alternating magnetic fields induce a current in the at least one conductor loop. The resulting magnetic fields of the conductor loop oppose the magnetic fields of the currents in the traction cables and weaken them. The arrangement of the conductor loop relative to the traction cables depends on the region in which the resulting overall field is to be minimized.Compared to other known methods, laying a conductor loop is cost-effective and simple. Furthermore, the shielding effect can be adjusted via the cross-section of the conductor loop, with larger cross-sections providing better shielding. This is due to the lower ohmic resistance, allowing for higher currents.

[0011] At least two conductor loops are arranged on the traction lines.

[0012] In one embodiment, the conductor loop has an insulating sheathing, so that no electrical feedback to other components can occur due to the compensating currents.

[0013] Alternatively, the conductor loop is at least partially integrated into the sheathing of the traction cables. This optimizes the installation space and further reduces the distance between the traction cables and the conductor loop.

[0014] In this design, at least one conductor loop rests at least partially on the traction lines. The advantage lies in the very small distance and the very simple method of attaching the conductor loop. For example, the conductor loop can be attached to the traction lines using cable ties, adhesive, or wrapping tape.

[0015] In a further embodiment, the at least one conductor loop is arranged to the traction lines in such a way that the connection between the center point of one traction line and a center point of the conductor loop is parallel to the connection between the center point of the other traction line and the center point of the other branch of the conductor loop.

[0016] In another embodiment, the at least one conductor loop has a rectangular cross-section, which allows for a very flat, compact design.

[0017] In another embodiment, the conductor loop is made of copper or aluminum, so that due to the high conductivity the compensating currents are correspondingly high.

[0018] The invention is explained in more detail below with reference to preferred embodiments. The figures show: Fig. 1a a cross-section through a traction network in a first non-claimed embodiment, Fig. 1b a cross-section through a traction network in a second non-claimed embodiment, Fig. 1c a cross-section through a traction network in a third non-claimed embodiment, Fig. 1d a cross-section through a traction network in a fourth non-claimed embodiment, Fig. 1e a cross-section through a traction network in a fifth non-claimed embodiment, Fig. 1f a cross-section through a traction network in a sixth non-claimed embodiment, Fig. 1g a cross-section through a traction network in a seventh non-claimed embodiment, Fig. 1h a cross-section through a traction network in an eighth non-claiming embodiment, Fig. 1i a cross-section through a traction network in a ninth embodiment, Fig. 2 a top view of an embodiment according to Fig. 1c and Fig. 3 a schematic representation of the currents.

[0019] In the Fig. Figure 1a shows a cross-section through a portion of a traction network 1 in a first embodiment. The traction network comprises a first traction line 2 with an insulating sheath 3 and a second traction line 4 with an insulating sheath 5. A conductor loop 6, which is, for example, rectangular, is arranged above the traction lines 2 and 4 (sa). Fig. 2) The conductor loop 6 is arranged relative to the traction lines 2, 4 such that a connecting line V1 between the midpoint of the first traction line 2 and the midpoint of one leg of the conductor loop 6 is parallel to a connecting line V2 between the midpoint of the second traction line 4 and another leg of the conductor loop 6. The first traction line 2 is connected to the positive terminal of a high-voltage battery, and the second traction line 4 is connected to the negative terminal of the high-voltage battery. The time-varying magnetic fields resulting from the current ripples on the traction lines 2, 4 generate compensating currents in the closed conductor loop 6. These compensating currents then also generate a magnetic field, which weakens the magnetic field caused by the currents in the traction lines 2, 4. A region B, which is to be shielded from magnetic fields, is shown schematically.

[0020] In the Fig. 1b shows an alternative embodiment, the only difference being that of the embodiment according to Fig. 1a is that the conductor loop 6 has an insulating sheath 7. Here too, the conductor loop 6 is arranged to the traction lines such that a connecting line V1 between the midpoint of the first traction line 2 and the midpoint of one leg of the conductor loop is parallel to a connecting line V2 between the midpoint of the second traction line 4 and another leg of the circuit board 6.

[0021] In the Fig. Figure 1c shows a further alternative embodiment in which the conductor loop 6 or its sheathing 7 rests on the traction lines 2, 4 or their sheathing 3, 5. The conductor loop can rest loosely or be fastened, for example with adhesive, cable ties or winding board.

[0022] In the Fig. Figure 1d shows another alternative embodiment.

[0023] In the Fig. Figure 1e shows a further alternative embodiment, wherein the conductor loop 6 has two turns, the outer turn being arranged relative to the traction lines such that a connecting line V1 between the midpoint of the first traction line 2 and the midpoint of one leg of the conductor loop is parallel to a connecting line V2 between the midpoint of the second traction line 4 and another leg of the circuit board 6 and rests on the traction lines 2, 4. Alternatively, two conductor loops 6, each with one turn, can also be used.

[0024] In the Fig. 1f and Fig. 1g further alternative embodiments are shown, wherein in Fig. 1f the conductor loop 6 partially and in Fig. 1g is fully integrated into the traction lines 2, 4, or more precisely, into their sheathing 3, 5. This can occur, for example, during the manufacturing process of the sheathing 3, 5. It should be noted that in the embodiment according to Fig. The 1g coating 7 can also be omitted.

[0025] In the Fig. Figure 1h shows an embodiment in which the cross-section of the conductor loop 6 is not round, but rectangular, so that a very flat design is possible.

[0026] In the Fig. Figure 1i shows an embodiment with two conductor loops 6, each having one turn.

[0027] All variants shown can be advantageous for the respective application with regard to their shielding effect against magnetic fields for the areas to be protected.

[0028] In the Fig. 2 is a top view of the embodiment according to Fig. 1c is shown.

[0029] In the Fig. Finally, the current directions for a given operating situation are shown in section 3. It is shown that the current I L in conductor loop 6 in the sections that are parallel to the traction lines 2, 4, the current is opposite to the current I T in the assigned traction lines 2, 4. Reference symbol list 1 Traction network 2 first traction line 3. Sheathing 4 second traction line 5 Sheathing 6 conductor loop 7 Sheathing I L Current in the conductor loop I T Electricity in the traction line V1, V2 connecting line

Claims

[1] Traction network (1) in an electric or hybrid vehicle, comprising a first and a second traction line (2, 4), each having an insulating sheath (3, 5), wherein the first traction line (2) is connected to a positive terminal of a high-voltage battery and the second traction line (4) is connected to a negative terminal of the high-voltage battery, wherein at least one closed conductor loop (6) with at least one turn is arranged on the traction lines (2, 4), wherein the traction lines (2, 4) and the at least one conductor loop (6) are electrically insulated, wherein the conductor loop (6) rests at least partially on the traction lines (2, 4) or the conductor loop (6) is at least partially integrated into the sheath (3, 5) of the traction lines (2, 4), wherein at least two conductor loops (6) are arranged on the traction lines (2, 4). [2] Traction network according to claim 1, characterized by, that the conductor loop (6) has an insulating sheath (7). [3] Traction network according to one of the preceding claims, characterized by , that at least one conductor loop (6) is arranged to the traction lines (2, 4) such that a connecting line V1 between the midpoint of the first traction line (2) and the midpoint of one leg of the conductor loop is parallel to a connecting line V2 between the midpoint of the second traction line (4) and another leg of the conductor loop (6). [4] Traction network according to one of the preceding claims, characterized by , that at least one conductor loop (6) has a rectangular cross-section. [5] Traction network according to one of the preceding claims, characterized by , that the conductor loop (6) is made of copper or aluminium.

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