Power electronic circuitry and motor vehicle

Abstract

Power electronic circuit (10), in particular pulse inverter, comprising a power board (11) having a power section (12), and a control board (13) having a control section (14), wherein the power board (11) and the control board (13) are separated such that the power board (11) is arranged for direct cooling in a wet area (16) bounded by a housing (15) and the control board (13) is arranged outside the housing (15) in a dry area (17) separated from the wet area (16) by the housing (15), wherein the power board (11) and the control board (13) are connected for contactless energy transfer from the power board (11) towards the control board (13) via inductively acting transmitting and receiving devices (19, 20) and / or optically acting transmitting and receiving devices (19, 20) and / or thermally acting transmitting devices (19, 20). and receiving equipment (19, 20) are coupled,and wherein the housing (15) has at least one magnetically and / or optically and / or thermally transparent section (21), wherein the contactless energy transfer from the power board (11) towards the control board (13) serves the redundant power supply of the control board (13) for the power supply of the same from a low-voltage electrical system of the motor vehicle.

Description

[0001] The invention relates to a power electronic circuit and a motor vehicle with a power electronic circuit.

[0002] Power electronic circuits are installed in electric vehicles and hybrid vehicles. A power electronic circuit can be designed as a pulse-controlled inverter. Power electronics is used to transfer electrical energy between an electric motor serving as the drive unit and a high-voltage traction battery.

[0003] It is already known in practice to directly cool power electronic circuits with a liquid cooling medium that flows directly around the components of the power electronic circuit. While a so-called power section of the power electronic circuit may be directly surrounded by the liquid cooling medium, a control section may not come into contact with the liquid cooling medium under any circumstances. Effectively cooling a power electronic circuit under these conditions and, moreover, supplying the control section of the power electronic circuit with electrical energy from the power section has been difficult to date.

[0004] WO 2012 / 037 444 A2 discloses a system for contactless and / or wireless transmission of power and / or data between and / or within electronic devices.

[0005] DE 10 2017 207 318 A1 discloses a device having a first circuit board comprising a first contactless communication unit, a second circuit board comprising a second contactless communication unit, and a line structure comprising a radio frequency channel for directing contactless signals communicated between the first and second contactless communication units.

[0006] EP 2 284 849 B1 discloses an electronic device comprising a first electronic circuit substrate to which a first coil is connected, and a second electronic circuit substrate to which a second coil is connected, wherein power is transferred from the first coil to the second coil by electromagnetic induction.

[0007] WO 2017 / 158 574 A1, WO 2009 / 116 025 A2 and DE 10 2011 056 265 A1 disclose further prior art.

[0008] DE 10 2021 130 926 A1 discloses a power electronic circuit with a circuit board body comprising a copper metal plate and an electrically non-conductive plastic base body on both sides of the copper metal plate. The circuit board body of the power electronic circuit partially defines a cavity in a housing with its wet side, wherein cooling fluid is arranged in the cavity. The metal plate of the circuit board body of the power electronic circuit has an opening that serves for the inductive transmission of signals, specifically between inductive transmitter-receiver elements.

[0009] Based on this, the invention is based on the object of providing a power electronic circuit whose power section can be effectively cooled and whose control section can be advantageously supplied with electrical energy. Furthermore, a motor vehicle with such a power electronic circuit is to be provided.

[0010] This object is achieved by a power electronic circuit according to claim 1 and a motor vehicle according to claim 10.

[0011] The power electronic circuit according to the invention has a power board with a power section and a control board with a control section, wherein the power board and the control board are separated in such a way that the power board is arranged in a wet area delimited by a housing for direct cooling of the power board and the control board is arranged outside the housing in a dry area separated from the wet area by the housing, wherein the power board and the control board are coupled for contactless energy transmission starting from the power board in the direction of the control board via inductive and / or optical and / or thermally acting transmitting and receiving devices, and wherein the housing has a magnetically and / or optically and / or thermally permeable section.

[0012] The power electronic circuit according to the invention is preferably a pulse-controlled inverter. However, the power electronic circuit can also be another power electronic circuit.

[0013] According to the invention, the contactless energy transfer from the power board towards and onto the control board serves to provide redundant power to the control board, preferably redundant to the power supply thereof from a low-voltage electrical system of the motor vehicle.

[0014] By separating the power board located in the wet area from the control board located in the dry area, it is possible to cool the power board directly and prevent the control board from coming into contact with the coolant. The housing separates the wet area from the dry area, whereby the energy transfer from the power board to the control board to supply the control board with electrical energy takes place contactlessly, namely via inductive and / or optical and / or thermally acting transmitting and receiving devices, which interact with a magnetically and / or optically and / or thermally permeable section of the housing for contactless energy transfer.

[0015] This enables effective cooling of the power board and thus the power section of a power electronic circuit, the prevention of contact of the control board and thus the control section of the power electronic circuit with the liquid cooling medium and, in addition, an effective power supply of the control board from the power board without the risk of leaks and therefore without the risk of unwanted contact of the control board with the liquid cooling medium.

[0016] If the low-voltage electrical system of the motor vehicle does not allow for an electrical power supply and therefore a voltage supply to the control board of the power electronic circuit, the voltage supply to the control board of the power electronic circuit can be ensured via contactless energy transfer from the power board of the power electronic circuit.

[0017] If the power board and the control board are inductively coupled for contactless energy transmission, the power board has at least one coil acting as a transmitting device, and the control board has at least one coil acting as a receiving device. If the power board and the control board are optically coupled for contactless energy transmission, the power board has at least one optical energy source acting as a transmitting device, in particular a laser diode, and the control board has at least one optical energy receiver acting as a receiving device, preferably a phototransistor.If the power board and the control board are thermally coupled for contactless energy transfer, a Peltier element coupled to the control board is arranged outside the housing, adjacent to the thermally permeable section of the housing. The Peltier element converts the thermal energy emitted by the power section of the power board, which flows through the thermally permeable section of the housing toward the Peltier element, into electrical energy. All of these variants allow reliable contactless energy transfer from the power board located in the wet area to the control board located in the dry area, without the risk of unwanted contact between the control board and the liquid cooling medium.

[0018] Preferably, the housing of the power electronic circuit is magnetically shielding and / or optically shielding and / or thermally shielding outside the at least one magnetically permeable and / or optically permeable and / or thermally permeable section. This is preferred in order to maintain an otherwise desired shielding effect of the housing of the power electronic circuit against other components, for example, against electromagnetic radiation from other components in the motor vehicle.

[0019] Preferred developments of the invention will become apparent from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 a schematic representation of a first power electronic circuit, Fig. 2 a schematic representation of a second power electronic circuit, Fig. 3 a schematic representation of a third power electronic circuit, Fig. 4 a motor vehicle.

[0020] The invention relates to a power electronic circuit, in particular a pulse-controlled inverter. The power electronic circuit, in particular the pulse-controlled inverter, is preferably a component of a motor vehicle designed as an electric vehicle or hybrid vehicle.

[0021] Fig. Figure 1 shows a first embodiment of a power electronic circuit 10, wherein the power electronic circuit 10 comprises a power board 11 with a power section 12 and a control board 13 with a control section 14. The power board 11 also comprises gate drivers.

[0022] The power board 11 and the control board 13 are separated in such a way that the power board 11 is arranged in a wet area 16 defined by a housing 15 of the power electronic circuit 10 for direct cooling thereof with a liquid cooling medium. The control board 13 is arranged outside the housing 15 and thus outside the wet area 16 in a dry area 17 separated from the wet area 16 by the housing 15, wherein Fig. 1 shows a highly schematic representation of a separation layer or wall 18 of the housing 15 separating the wet area 16 from the dry area 17.

[0023] The control board 13 can be coupled directly to an on-board electrical system of a motor vehicle via a plug connection (not shown) in order to supply the control board 13 and thus the control part 14 thereof with electrical energy from the on-board electrical system.

[0024] In order to ensure an electrical supply of the control board 13, in particular the control part 14, with electrical energy even when the electrical energy cannot be provided by the on-board network, the power board 11 and the control board 13 are coupled for contactless energy transmission from the power board 11 in the direction of the control board 13 via at least one transmitting device 19 and one receiving device 20, wherein Fig. 1, the transmitting device 19 and the contact device 20, which serve for contactless energy transmission, starting from the power board 11 in the direction of the control board 13 and thus to the control board 13, are designed as inductively acting transmitting and receiving devices 19, 20. The housing 15, namely in Fig. 1 the separation layer or wall 18 of the housing 15 separating the wet area 16 from the dry area 17, has a Fig. 1 magnetically permeable section 21 which is arranged between the transmitting device 19 of the power board 11 and the receiving device 20 of the control board 13.

[0025] The inductively acting transmitting device 19 of the power board 11 is preferably designed as a primary inductance or primary coil or first coil, and the magnetically acting transmitting device 20 of the control board 20 is preferably designed as a secondary inductance or secondary coil or second coil. A magnetic field 22 generated by the inductance or coil 19 acting as a transmitting device extends between the inductance or coil of the power board 11 acting as the transmitting device 19 and the inductance or coil of the control board 13 acting as the receiving device 20 through the magnetically permeable section 21 of the housing 15 of the power electronic circuit 10, in order to Fig. 1, the electrical energy is transferred from the power board 11 towards the control board 13.

[0026] The magnetically permeable section 21 of the housing 15 can be made of a plastic, in particular a PE plastic or PP plastic. Preferably, the housing 18 is magnetically shielding outside the magnetically permeable section 21 and metallic outside this section 21.

[0027] Fig. 2 shows a second embodiment of a power electronic circuit 10, wherein only those details are discussed below through which the power electronic circuit 10 of the Fig. 2 from the power electronic circuit 10 of the Fig. 1. While in Fig. 1 the transmitting and receiving devices 19, 20 act inductively, act in Fig. 2 the transmitting and receiving devices 19, 20 optically. Thus, the transmitting device 19 of the power board 11 is in Fig. 2 as an optical energy source, preferably as a photodiode, and the receiving device 20 of the control board 13 as an optical energy receiver, preferably as a phototransistor. The transmitting device 19 of the power board 11, designed as a photodiode, is preferably a laser diode, wherein laser radiation generated by the laser diode or waves emitted by the laser diode then extend from the transmitting device 19 of the power board 11 through an optically transparent section 21 of the housing 15 to the phototransistor of the control board 13, which acts as a receiving device 20. Thus, the control board 13, namely the control part 14 thereof, can be supplied with electrical energy from the power board 11 via optically acting transmitting and receiving devices 19, 20. The contactless energy transmission is in Fig. 2 is again visualized by an arrow 22.

[0028] The optically transmissive section 21 may be a section made of a transparent plastic, for example acrylic glass, or a section made of transparent glass.

[0029] A further embodiment of a power electronic circuit 10 according to the invention shows Fig. 3, where also for Fig. 3 only those details are discussed which Fig. 3 of Fig. 1 differs.

[0030] In Fig. 3, the transmitting device 19 and the receiving device 20 for contactless energy transmission starting from the power board 11 in the direction of the control board 13 are designed as thermally acting transmitting and receiving devices 19, 20.

[0031] In Fig. 3, the power section 12 serves as a thermally active transmitter 19 of the power board 11, with a thermally active receiver 20 configured as a Peltier element cooperating with the control board 13. The Peltier element converts the thermal energy emitted by the power section 12 of the power board 11 into electrical energy, with the thermal energy emitted by the power section 12 flowing through the thermally permeable section 21 of the housing 15 toward the Peltier element 20. The Peltier element 20 converts the thermal energy into electrical energy as a result of the so-called seedback effect. Fig. 3, the section 21 of the housing 15 is formed from a highly thermally conductive material, in particular from a metallic material.

[0032] The highly thermally conductive material of section 21 of housing 15 differs from the material of other sections of the housing, which is less thermally conductive. This allows the thermal energy to be transferred in a targeted manner toward the Peltier element 20 and to ensure the highest possible temperature or temperature difference in the area of ​​the Peltier element 20.

[0033] According to the invention, in a power electronic circuit 10 which has a power board 11 arranged in a wet area and directly cooled by a liquid cooling medium and a control board 13 arranged separate therefrom in a dry area 17, a contactless energy transfer takes place, starting from the power board 11 in the direction of the control board 13 to supply the control board 13 with electrical energy, without a plug connection between the power board 11 and the control board 13 and therefore without the need for a breakthrough required for a plug connection and thus a leak point between the wet area 16 and the dry area 17 and therefore without the risk of the control board 13 unintentionally coming into contact with the liquid cooling medium which serves to directly cool the power board 11.No additional openings and seals are required in the separation point between the power board 11 and the control board 13 and therefore between the power section 12 and the control section 14.

[0034] The invention further relates to a motor vehicle 30 having an electric machine 31 serving as a drive unit and a high-voltage traction battery 32. Between the electric machine 31 and the high-voltage traction battery 32, a power electronics unit 33 is connected for transmitting electrical energy between the electric machine 31 and the high-voltage traction battery 32, wherein the power electronics unit 33 has at least one power electronic circuit 10 which, as described above in connection with Fig. 1 to 3.

[0035] It should be noted that several differently acting transmitting and receiving devices, i.e. magnetically acting transmitting and receiving devices with optically acting transmitting and receiving devices or magnetically acting transmitting and receiving devices with thermally acting transmitting and receiving devices or even optically acting transmitting and receiving devices with thermally acting transmitting and receiving devices can be used in combination with one another for contactless energy transmission between the power board 11 and the control board 13.

Claims

[1] Power electronic circuit (10), with a power board (11) having a power section (12), with a control board (13) having a control part (14), wherein the power board (11) and the control board (13) are separated in such a way that the power board (11) is arranged in a wet area (16) delimited by a housing (15) for direct cooling thereof, and the control board (13) is arranged outside the housing (15) in a dry area (17) separated from the wet area (16) by the housing (15), wherein the power board (11) and the control board (13) are coupled for contactless energy transmission from the power board (11) towards the control board (13) via inductively acting transmitting and receiving devices (19, 20) and / or optically acting transmitting and receiving devices (19, 20) and / or thermally acting transmitting and receiving devices (19, 20), wherein the housing (15) has at least one magnetically and / or optically and / or thermally permeable section (21), wherein the contactless energy transfer from the power board (11) in the direction of the control board (13) serves to provide the redundant voltage supply of the control board (13) for supplying the same with voltage from a low-voltage electrical system of the motor vehicle. [2] Power electronic circuit (10) according to claim 1, characterized by that when the power board (11) and the control board (13) are inductively coupled for contactless energy transmission, the power board (11) has at least one inductance or coil acting as a transmitting device (19) and the control board (13) has at least one inductance or coil acting as a receiving device (20). [3] Power electronic circuit (10) according to claim 2, characterized bythat a magnetic field generated by the inductance or coil of the power board (11) acting as a transmitting device (19) extends through the magnetically permeable section (21) of the housing (15) to the inductance or coil of the control board (13) acting as a receiving device (20). [4] Power electronic circuit (10) according to claim 1, 2 or 3, characterized by that when the power board (11) and the control board (13) are optically coupled for contactless energy transmission, the power board (11) has at least one optical energy source acting as a transmitting device (19), and the control board (13) has at least one phototransistor acting as a receiving device (20). [5] Power electronic circuit (10) according to claim 4, characterized bythat a laser radiation generated by the laser diode of the power board (11) acting as a transmitting device (19) or waves emitted by the laser diode extends through the optically transparent section (21) of the housing (15) to the phototransistor of the control board (13) acting as a receiving device (20). [6] Power electronic circuit (10) according to one of claims 1 to 5, characterized by that when the power board (11) and the control board (13) are thermally coupled for contactless energy transfer, a Peltier element coupled to the control board (13) is arranged outside the housing (15) adjacent to the thermally permeable section (21) thereof as a receiving device. [7] Power electronic circuit (10) according to claim 6, characterized bythat the Peltier element converts thermal energy emitted by the power section (12) of the power board (11), which flows via the thermally permeable section (21) of the housing (15) in the direction of the Peltier element, into electrical energy. [8] Power electronic circuit (10) according to one of claims 1 to 7, characterized by that the housing (15) is magnetically and / or optically and / or thermally shielding outside the at least one magnetically and / or optically and / or thermally permeable section (21). [9] Power electronic circuit (10) according to one of claims 1 to 8, characterized by that it is a pulse inverter. [10] Motor vehicle (30), with an electric machine (31) serving as a drive unit, with a high-voltage traction battery (32) for storing electrical energy and with power electronics (33) for transmitting electrical energy between the electric machine (31) and the high-voltage traction battery (32) and for converting the electrical energy, characterized by that the power electronics of the motor vehicle (30) comprises at least one power electronic circuit (10) according to one of claims 1 to 9.

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