CIRCUIT ARRANGEMENT

Abstract

A circuit arrangement for an onboard network of a motor vehicle, includes a line having a first inductivity and connecting a component of a power electronics of an onboard network with an element, wherein the component is adapted for being clocked during operation of the power electronics at a clock frequency; and an absorber circuit assigned to the line and having a second inductivity and a capacitance, wherein the second inductivity of the absorber circuit is coupled with the first inductivity of the line.

Claims

1. A circuit arrangement for an onboard network of a motor vehicle, said circuit arrangement comprising: a line having a first inductivity and connecting a component of a power electronics of an onboard network with an element, said component being adapted for being clocked during operation of the power electronics at a clock frequency; and an absorber circuit assigned to the line and having a second inductivity and a capacitance, said second inductivity of the absorber circuit being coupled with the first inductivity of the line.

2. The circuit arrangement of claim 1, further comprising a set of lines which comprises said line and a further line, said set of lines comprising the first inductivity and connecting the at least one component with the at least one element, said absorber circuit being assigned to the set of lines, said second inductivity of the absorber circuit being coupled with the first inductivity of the set of lines.

3. The circuit arrangement of claim 2, wherein at least two lines of the set of lines have a common inductivity, said absorber circuit being assigned to the common inductivity, said second inductivity of the absorber circuit being coupled with the common inductivity of the at least two lines.

4. The circuit arrangement of claim 2, wherein at least one of the lines comprised by the set of lines has an individual inductivity, said absorber circuit being assigned to the individual inductivity, said second inductivity of the absorber circuit being coupled with the individual inductivity of the at least one line of the set of lines.

5. The circuit arrangement of claim 2, wherein the set of lines comprises two lines, wherein a first one of the two lines extends straight and a second one of the two lines includes a loop, which is wound in opposite direction relative to the first line, wherein the first line and the loop of the second line have a common inductivity, said second inductivity of the absorber circuit being coupled with the common inductivity.

6. The circuit arrangement of claim 1, wherein the first inductivity of the line is configured as a throttle.

7. The circuit arrangement of claim 2, wherein the first inductivity of the line is configured as a part of at least one core, which surrounds at least one of the line of the set of lines.

8. The circuit arrangement of claim 1, further comprising another capacitance connected in parallel to the first inductivity of the line.

9. The circuit arrangement of claim 1, wherein a resonance frequency of the absorber circuit has an n-fold value of said clock frequency, with n being an integer number greater than or equal to 1.

10. The circuit arrangement of claim 1, wherein the absorber circuit further comprises a resistance, said second inductivity, said capacitance and said resistance being connected in series, wherein a bandwidth of the absorber circuit is adjustable via a value of the resistance.

11. An onboard network for a motor vehicle, said onboard network comprising: a power electronics including a component adapted for being clocked during operation of the power electronics at a clock frequency; an element connected to the power electronics; a line connecting the component with the element, said line having a first inductivity; and an absorber circuit having a second inductivity and a capacitance, and being assigned to the line, said second inductivity of the absorber circuit being coupled with the first inductivity of the line.

12. The onboard network of claim 11, wherein the element is configured as an energy storage, which is connected with the at least one component via a set composed of said line and a further line.

13. The onboard network of claim 11, wherein the element is configured as an electric machine, which is connected with the component via a set composed of said line and two further lines.

14. The onboard network of claim 11, wherein the element, the component of the power electronics and the line are configured as a part of a device.

15. The onboard network of claim 11, wherein the line is surrounded by a core made of a material which has a magnetic permeability m of greater than 1.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0022] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which

[0023] FIG. 1 shows a schematic representation of an example for an absorber circuit, which is configured as a part of an embodiment of the circuit arrangement according to the invention.

[0024] FIG. 2 shows a schematic representation of an example of an onboard network, for which an embodiment of a circuit arranged according to the invention is to be provided.

[0025] FIG. 3 shows a schematic representation of a first embodiment of the onboard network on the basis of the onboard network of FIG. 2 and a first embodiment of the circuit arrangement according to the invention.

[0026] FIG. 4 shows a schematic representation of a second embodiment of the onboard network according to the invention on the basis of the onboard network of FIG. 2 and a second embodiment of the circuit arrangement according to the invention.

[0027] FIG. 5 shows a schematic representation of a detail of a third embodiment of the onboard network on the basis of the onboard network of FIG. 2 and a third embodiment of the circuit arrangement according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0028] Throughout all the Figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

[0029] The absorber circuit 16 shown in FIG. 1 has an inductivity 22, a capacitance 32 or capacitor and an electric resistance 34. Hereby the electrical absorber circuit 16 is configured as a part of an embodiment of the electrical circuit arrangement 14, 18 or 20 as it is shown in one of the FIGS. 3 to 5. The absorber circuit 16 schematically shown in FIG. 1 is hereby representative for each absorber circuit 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h of one of the embodiments of the circuit arrangement 14, 18, 20. FIG. 1 also shows a line 11 of an onboard network 2, 2a, 2b, 2c as it is schematically shown in one of the FIGS. 2 to 5 below. This at least one line 11 represents and/or includes at least one line 11a, 11b, 11c, 11d, 11e, 11f of the respective onboard network 2, 2a, 2b, 2c and thus optionally also a set 10a, 10b, 10c of multiple lines 11a, 11b, 11c, 11d, 11e, 11f as schematically shown in FIGS. 2 to 5 below.

[0030] The at least one line 11a, 11b, 11c, 11d, 11e, 11f includes at least one inductivity 24. For realizing an embodiment of the circuit arrangement 14, 18, 20 according to the invention it is provided that the absorber circuit 16 is assigned to the at least one line 11 or 11a, 11b, 11c, 11d, 11e, 11f. Hereby the inductivity 22 of the absorber circuit 16 or 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h is arranged adjacent the at least one line 11 or 11a, 11b, 11c, 11d, 11e, 11f and is inductively coupled with the same, wherein such an inductive coupling is indicated in FIG. 1 with a circle 30. However, the absorber circuit 16 or 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h is galvanically decoupled for the at least one line 11 or 11a, 11b, 11c, 11d, 11e, 11f.

[0031] The example of the onboard network 2 for a motor vehicle schematically shown in FIG. 2 includes as components an energy storage 4 configured as a battery, a power electronics 6, which includes as a component 7 inter alia at least one pulse inverter, and an electric machine 8, which can be either operated as a generator or as a motor. When the electric machine 8 is operated as a generator mechanical energy is converted with this electric machine into electrical energy. When the electric machine 8 is operated as a motor electrical energy can be converted with the electric machine 8 into mechanical energy. Hereby it is provided that the electrical machine 8 has three phases.

[0032] In the present case the energy storage 4 and the at least one component 7 of the power electronics 6 are connected via a set 10a made of two lines 11a, 11b, in the present case traction lines. In addition the power electronics 6 and the electric machine 8 are connected with each other via a second set 10b of lines in this case three lines 11c, 11d, 11e, in the present case phase lines. Each phase of the electric machine 8 is assigned a line 11c, 11d, 11e, which form the second set 10b of lines.

[0033] The disclosed onboard network 2 is provided for a motor vehicle, which can be driven or propelled with at least one electric machine 8, as disclosed herein. Accordingly the motor vehicle is either configured as a pure electric vehicle, which can be driven purely electrically, or as hybrid vehicle. When the motor vehicle is configured as a hybrid vehicle it includes, beside the electric machine 8, at least one further motor for propulsion, usually an internal combustion engine. It is also possible that an onboard network 2 has multiple power electronics 6 and electric machines 8.

[0034] The at least one component 7 of the power electronics 6 is clocked during operation of the onboard network 2 with an adjustable clock frequency. This clock frequency usually has a value of multiple thousand hertz. A harmonic wave, for example a first harmonic wave, of this clock frequency has a frequency with a value which is for example twice as high as the frequency value of the clock frequency. When the clock frequency of the at least one component 7 has a value of 9 kHz, the first harmonic wave has a frequency with a value of 18 kHz.

[0035] During operation of the power electronics 6 it the at least one component 7 may develop an electromagnetic field, which also affects the energy storage 4 and the electric machine 8. Hereby the electric machine 8 may be excited at the frequency of a harmonic wave to an audible whistling. It is further possible that the energy storage 4 is also excited by the electromagnetic field of the at least one component 7 of the power electronics 6. Accordingly the electromagnetic field of the at least one component 7 of the power electronics 6 may interfere with an operation of the energy storage 4 and the electric machine 8. It is also possible that the electromagnetic filed is emitted via the lines 11a, 11b, 11c, 11d, 11e. It is also possible that due to the emitted electromagnetic filed of the at least one component 7 of the power electronics further here not shown elements of the onboard network 2 or the motor vehicle are subjected to interference.

[0036] The first embodiment of the circuit arrangement 14 according to the invention for the first embodiment of the onboard network 2a is schematically shown in FIG. 3 and includes a first absorber circuit 16a and a second absorber circuit 16b.

[0037] FIG. 3 further shows a first inductivity 24a, which in this case is assigned to the two lines 11a, 11b of the first set 10 of lines 11a, 11b. Assigned to this common inductivity 24 is the first absorber circuit 16a whose inductivity 22 is coupled with the common inductivity 24a of the first set 10a of lines 11a, 11b. Hereby it is further provided that the common inductivity 24a is configured as a part of a core which has a magnetic permeability μ>1 and surrounds both lines 11a, 11b. In the present case a capacitance 26a is connected in parallel to the common inductivity 24a.

[0038] In the present case a second inductivity 24b is assigned to the second set 10b, which includes the lines 11c, 11d, 11e. This second inductivity 24b, which is configured as common inductivity 24b for all lines 11c, 1d, 11e, is assigned the second absorber circuit 16b, whose inductivity 22 is coupled with the common inductivity 24b of the second set 10b of lines 11c, 11d, 11e. In addition the common inductivity 24b is configured as a part of a core, here a ferrite core, which surrounds all three lines 11c, 11d, 11e. As an alternative the core is made of a nano-crystalline material or another material with a permeability of >1. In the present case a capacitance 26b is connected in parallel to the common inductivity 24b.

[0039] The lines 11a, 11b, 11c, , 11d, 11e are arranged at least between the power electronics 6 and the components, i.e., the energy storage 4 and the electric machine 8 of the onboard network 2a. In addition in the present embodiment it is provided that these lines 11a, 11 b, 11c, 11d, 11e are at least partially also arranged inside the power electronics 6 and are connected with e at least one component 7. In an embodiment at least one line 11a, 11b, 11c, 11 d, 11e is partially arranged in a housing of the power electronics 6. A common inductivity 24a, 24b, as shown in FIG. 3, is arranged between the power electronics 6 and the energy storage 4 or between the power electronics 6 and the electric machine 8. It is also possible that the inductivity 24a, 24b is arranged between the at least one component 7 and the energy storage 4 or between the at least one component 7 and the electric machine 8 inside the housing of the power electronics 6, for example between a connection of the respective line 11a, 11b, 11c, 11d, 11e and the at least one component 7. Correspondingly it is possible that an absorber circuit 16a, 16b, which is assigned to the inductivity 24a, 24b, is arranged outside of the housing of the power electronics 6 or inside the housing, usually between a respective power connection and the at least one component 7.

[0040] In an embodiment the at least one component 7 of the power electronics 6 is for example configured as a bipolar transistor with insulated gate electrode (IGBT). When contactors of the energy storage 4, which is configured as a battery may potentially be interfered with due to the electromagnetic field of the at least one component 7 the absorber circuit 16a is in this case to be arranged between the at least one component 7 and the contactors of the energy storage 4. In an embodiment it is possible that the lines 11a, 11b also partially extend inside the housing of the energy storage 4 and the inductivity 24a is also arranged inside the housing of the energy storage 4 or the power electronics 6. In this case the first absorber circuit 16a is also partially arranged inside the housing for example between the contactors and power connections for the lines 11a, 11b. Correspondingly it is also possible that the lines 11c, 11d, 11e and the common inductivity 24 are also arranged inside a housing of the electric machine 8 or the power electronics 6. In this case it is possible in an embodiment to arrange the absorber circuit 16b, which is assigned to the inductivity 24b, also inside the housing of eh electric machine 8.

[0041] With this first embodiment of the circuit arrangement 14 a so-called Common-Mode interference-suppression is achieved for the onboard network 2a. Depending on the definition it is provided that the at least one component 7 of the power electronics 6 is configured as a interference source and the energy storage 4 and the electric machine 8 are configured and/or referred to as interference sink. In the present case the absorber circuits 16a, 16b are arranged between the power electronics 6 and respectively a further element, i.e., the energy storage 4 and the electric machine 8 of the onboard network 2a.

[0042] In the second embodiment of the onboard network 2b according to the invention it is provided that each line 11a, 11b, 11c, 11d, 11e between the at last one component 7 of the power electronics 6 and a respective element, i.e., the energy storage 4 or the electric machine 8 of the onboard network 2b, has its own inductivity 24c, 24d, 24e, 24f, 24g to which respectively a capacitance 26c, 26d, 26e, 26f, 26g is connected in parallel. Hereby it is further provided that at least one respective inductivity 24c, 24d, 24e, 24f, 24g is configured as a part of a ferrite core which surrounds the respective line 11a, 11b, 11c, 11d, 11e.

[0043] In the second embodiment of the circuit arrangement 18 illustrated in FIG. 4 each inductivity 24c, 24d, 24e, 24f, 24g of a respective line 11a, 11b, 11c, 11d, 11e is assigned an absorber circuit 16c, 16d, 16e, 16f, 16g as it is shown exemplarily by way of the absorber circuit 16 of FIG. 1. Hereby a respective inductivity 2 of an absorber circuit 16c, 16d, 16e, 16f, 16g is coupled with the respective inductivity 24c, 24d, 24e, 24f, 24g of the respective line 11a, 11b, 11c, 11d, 11e.

[0044] By providing a respective inductivity 24c, 24d, 24e, 24f, 24g for each line 11a, 11b, 11c, 11d, 11e to which a respective absorber circuit 16c, 16d, 16e, 16f, 16g is assigned a differential interference-suppression can be achieved with the second embodiment of the circuit arrangement 2b.

[0045] In the detail view of the third embodiment of the onboard network 11c, which is schematically shown in FIG. 5, only the power electronics 6 and the energy storage 4 are shown as components of the onboard network 2c, hereby the at least one component 7 of the power electronics 6 is connected with the energy storage 4 via lines 11b, 11f, wherein these two lines 11b, 11f form a further set 10c of lines 11b, 11f. Hereby it is provided that the line 11b extends directly and/or straight between the at least one component 7 and in the energy storage 4, whereas the line 11f has a winding in opposite direction and thus has a loop 13. The line 11b and the loop 13 of the 11f and thus both lines 11b, 11f have a common inductivity 24h to which a capacitance 26h is connected in parallel. Hereby it is possible that the inductivity 24h is configured as a part of a core, for example a ferrite core, which surrounds the line 11b and the loop 13 of the line 11f.

[0046] The third embodiment of the circuit arrangement 20 shown in FIG. 5 in the present case includes an absorber circuit 16h, which is configured according to the absorber circuit 16 of FIG. 1. This absorber circuit 16h is assigned to the common inductivity 24h of the set 10c of lines 11b, 11f. The inductivity 22 of the absorber circuit 16h is hereby coupled with the common inductivity 24h of the set 10c of lines 11b, 11f.

[0047] All absorber circuits 16, 16a 16b, 16c, 16d, 16e, 16f, 16g, 16h include a serial connection of the capacitance 32 and the inductivity 22 (as exemplarily shown in FIG. 1 for the absorber circuit 16), which is configured as a throttle or coil. Usually the Ohm's resistance 34 is to be set low. A resonance frequency f.sub.R depends on a value L of the inductivity 22 and a value C of the capacitance and is f.sub.R=0.5/π*(LC).sup.−0.5. A bandwidth of the resonance frequency f.sub.R can be adjusted by the resistance 34. In addition the resonance frequency can be adjusted in dependence on the clock frequency of the at least one component 7, wherein values L, C of the inductivity 22 and the capacitance 32 are to be selected. Usually the resonance frequency corresponds to an integer n-fold of the clock frequency. Each absorber circuit 16, 16a 16b, 16c, 16d, 16e, 16f, 16g, 16h can be inductively coupled via its inductivity 22 with a respective inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h for the at least one line 11 or 11a, 11b, 11c, 11d, 11e, 11f. IN an embodiment the value C of the inductivity 22 is adjusted to a respective value of the inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h of the onboard network 2, 2as, 2b, 2c as potential free system of the motor vehicle. Hereby the onboard network 2, 2a, 2b, 2c is configured as a D/C network and/or three-phase network. The value C of he capacitance 34 is to be selected as target frequency by taking the clock frequency of the at least one component 7 or an integer multiple of this clock frequency into account.

[0048] The frequency of a harmonic wave, for example the first harmonic wave, of the lock frequency of the at least one component 7 of the power electronics is for example 18 kHz and varies for example in dependence on a rotational speed of the electric machine 8 and a number of pole pairs of the electric machine. By taking such a deviation of the frequency of the harmonic wave into account a respective absorber circuit 16, 16a 16b, 16c, 16d, 16e, 16f, 16g, 16h can be configured broadband, which in turn can be realized by dimensioning of the resistance.

[0049] In an embodiment the inductivity 22 of the absorber circuit 16, 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h can be made of Vitroperm® or a nanocrystal and can have a high μ-value, which makes it possible to generate the resistance directly by the inductivity 22. A damping of the electromagnetic radiation of the at least one component 7 that can be achieved with the respective absorber circuit 16, 16a 16b, 16c, 16d, 16e, 16f, 16g, 16h also depends on a value of a respective inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h of the at least one line 11 or 11a, 11b, 11c, 11d, 11e, 11f, wherein a value of a respective inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h can for example be increased by multiple winding of core which is here configured as a ferrite core, which includes the respective inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h and/or by using a throttle as inductivity 24, 24a, 24c, 24d, 24e, 24f, 24g, 24h.

[0050] When an onboard network 2, 2a, 2b, 2c has multiple power electronics 6 and electric machines 8, the at least one absorber circuit 16, 16a 16b, 16c, 16d, 16e, 161, 16g, 16h can be used for at least one power electronics 6, multiple power electronics 6 or all power electronics 6. In the case of multiple absorber circuits 16, 16a 16b, 16c, 16d, 16e, 16f, 16g, 16h, these can have different resonance frequencies.

[0051] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: