Drive systems for electric vehicles, and electric vehicles

Abstract

To provide a drive system for an electric vehicle, and also to provide an electric vehicle.SOLUTION: A drive system according to the present invention is a drive system (10) for an electric vehicle (100) and includes, as drive configuration elements, a traction battery (12), an inverter (14), and an electrical machine (16). The drive system is formed so that the traction battery is electrically connected to the electrical machine via the inverter, and so that the traction battery is electrically connected to the inverter via respective high voltage connection elements (22, 24), and so that the inverter is electrically connected to the electrical machine. The drive system includes a cooling circuit (26) for cooling the drive configuration elements by a cooling medium (28). The drive system is formed so that the respective drive configuration elements and high voltage connection elements transport the cooling medium and are formed to form a part (30) of the cooling circuit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a drive system for an electric vehicle.

Background Art

[0002] (Patent Document 1) discloses a configuration of a plurality of electric vehicle drive components including a battery, an electric machine, an inverter, a cable core for conducting a large current, and a large current cable having a coolant channel between the cable sheath and the cable core. The vehicle drive components are connected to a plurality of cooling circuits and need to operate these cooling circuits for cooling.

[0003] (Patent Document 2) discloses a drive system for an electric vehicle including a battery, an inverter, and an electric machine. A cooling device is also provided, and the converter and the electric machine can be cooled by the cooling device. Other components are not cooled.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide an improved drive system in relation to the above.

Means for Solving the Problems

[0006] The above object is achieved by the drive system according to claim 1.

[0007] A drive system for an electric vehicle comprises a traction battery, an inverter, and an electromechanism as drive components. The traction battery is electrically connected to the electromechanism via the inverter. In this case, the traction battery is electrically connected to the inverter (DC voltage side) and the inverter is electrically connected to the electromechanism (AC voltage side) by high-voltage connection elements. The drive system preferably has a cooling circuit for cooling the drive components with a liquid cooling medium, where the drive components and high-voltage connection elements are each formed to transport the cooling medium, and (they together) form at least a part of the cooling circuit.

[0008] In other words, the drive components and high-voltage connection elements are each formed to be able to transport the cooling medium. Specifically, the drive components and high-voltage connection elements each have a channel section for transporting the cooling medium. In the assembled state (when the drive components and high-voltage connection elements are coupled to each other), the channel section forms a cooling medium channel, and thus part of the cooling circuit. Therefore, the current-conducting and power-conducting drive components and high-voltage connection elements also transport the cooling medium.

[0009] In other words, the current conduction line cores of the drive components and high-voltage connection elements extend side by side, for example in parallel, along with a channel section for a cooling medium that runs from the traction battery through the electrical high-voltage connection element between the traction battery and the inverter, through the inverter, through further high-voltage connection elements between the inverter and the electromechanism, and further through the electromechanism. Thus, the cooling path extends along with the current or power path. This contributes to optimized and uniform cooling of the drive components using simply designed means.

[0010] High-voltage connection elements are designed to transmit not only high voltages (e.g., 400-800 volts) but also high currents (e.g., 250-600 or 900 amperes). Therefore, high-voltage connection elements are sometimes also called high-current connection elements.

[0011] Electric vehicles are automobiles, particularly electric passenger cars and commercial vehicles. The drive system is used as a traction drive for electric vehicles. The inverter may be a pulse inverter in particular. Preferably, a liquid coolant, such as water or oil, can be used as the cooling medium.

[0012] A charging line can be connected to the traction battery, electrically connecting it to a charging socket (a charging socket provided in electric vehicles). The charging line can be connected to a cooling circuit and thus cooled.

[0013] Preferably, the high-voltage connection elements can be formed as high-voltage lines (single-wire or multi-wire high-voltage cables), plug connectors, busbars, or screws. This allows for the transmission of sufficiently large currents according to the respective requirements.

[0014] Preferably, each high-voltage connection element has a sheath surrounding the outside of the respective high-voltage connection element, and a channel section through which a cooling medium is transported is formed in the intermediate space between the sheath and the high-voltage connection element. In a compact design, this allows for the transfer of a large amount of heat.

[0015] Preferably, the drive component and the high-voltage connection element each have a connection interface for coupling the drive component to the high-voltage connection element, and the connection interface has, in each case, an electrical connection (for power or current conduction) and a fluid connection (for transporting a cooling medium). Thus, the electrical connection and the fluid connection are incorporated into the connection interface. By connecting the connection interface, the relevant drive component and the high-voltage connection element are electrically and fluidly interconnected.

[0016] Preferably, some or all of the drive components and high-voltage connection elements can be configured to be coolable by a cooling medium through direct cooling. Therefore, a cooling medium can be directly flowed around areas or regions of drive components and high-voltage connection elements that have particularly high cooling requirements. For this purpose, these areas or regions can be fluidly connected to a cooling circuit or cooling medium channel.

[0017] Preferably, a heat exchanger or cooler for controlling the temperature of the cooling medium can be connected upstream of the traction battery in the cooling circuit (in the direction of circulation of the cooling circuit or cooling medium). As a result, heat can be transferred between the cooling medium in the cooling circuit and the surroundings of the drive system. Therefore, for example, thermal energy absorbed by the cooling medium can be released into the surroundings by the heat exchanger.

[0018] Preferably, the drive system may have, as a further drive component, a gear mechanism coupled to and connected to the electromechanism, particularly downstream of the electromechanism, the gear mechanism having a gear mechanism heat exchanger, which is incorporated into a cooling circuit. The gear mechanism heat exchanger may be connected downstream of the electromechanism in the direction of circulation of the cooling circuit or the cooling medium. Using a heated cooling medium, the temperature of the gear mechanism oil can be controlled as the cooling medium of the cooling circuit passes through the gear mechanism heat exchanger. The cooling medium of the entire drive system can release heat to the gear mechanism oil by the gear mechanism heat exchanger. As a result, the efficiency of the gear mechanism can be increased. Alternatively or additionally, the gear mechanism or the gear mechanism oil can be cooled by a cooling circuit.

[0019] Preferably, the drive system may comprise at least two inverters, at least two electromechanisms, and at least two gear mechanisms having gear mechanism heat exchangers, in each case one inverter, one electromechanism, and one gear mechanism having a gear mechanism heat exchanger are combined to form a drive module. Thus, the drive system has two or more drive modules, which can, for example, drive individual wheels. For example, there may be one or two drive modules for driving a first axle (e.g., the front axle) and / or one or two drive modules for driving a second axle (e.g., the rear axle). In this case, the cooling circuit may, after flowing through, for example, a traction battery, be divided into two or more substreams, each substream flowing through its respective drive module. In this case, each substream flows through an inverter, an electromechanism, and the gear mechanism heat exchanger of the associated gear mechanism. After passing through the gear mechanism heat exchanger, two or more substreams of the cooling circuit can be combined again to form a single stream. The drive modules may be powered by a common traction battery or each may have its own battery.

[0020] Preferably, a pump for transporting the cooling medium can be connected upstream of the traction battery in the cooling circuit. Therefore, it is possible to ensure the transport of the cooling medium by, for example, increasing its pressure level before it enters the traction battery. The pump is connected particularly immediately upstream of the traction battery.

[0021] Preferably, an additional pump for transporting the cooling medium can be connected upstream of the electromechanism in the cooling circuit. This also contributes to the reliable transport of the cooling medium, for example, by increasing the pressure level of the cooling medium before it enters the electromechanism. The additional pump is particularly connected immediately upstream of the electromechanism.

[0022] The cooling circuit may preferably be the only cooling circuit of the drive system. In other words, all drive components and electrical high-voltage connection components are incorporated into the cooling circuit and temperature-controlled or cooled by the cooling circuit. By having only one cooling circuit in the drive system, the number and complexity of the components are reduced.

[0023] Preferably, the cooling circuit can have only one cooling medium. This contributes to simplifying the structure of the cooling circuit and reducing its complexity, as only one cooling medium needs to be provided and conveyed in the cooling circuit.

[0024] Preferably, one, a plurality, or all of the drive components can be fluidly connected to the cooling circuit by controllable switching valves respectively. Thus, each drive component can be connected to (e.g., opening the switching valve) or disconnected from (e.g., closing the switching valve) the cooling circuit according to the cooling requirements. Therefore, optimal and need-based thermal management for the drive system and the entire vehicle can be achieved. In each case, a bypass line that can be fluidly connected to the cooling circuit can be provided to the drive component. For example, when a switching valve in one of the drive components is closed, the cooling circuit can flow around that drive component and, for example, through the subsequent drive component in the flow direction.

[0025] Preferably, one or more heat exchange devices (heat exchangers or technical auxiliary systems) can be provided, where the first side of each heat exchange device is incorporated into the cooling circuit and the second side of the heat exchange device has a heat release connection for releasing thermal energy, particularly inside the vehicle or the interior of an electric vehicle. Thus, it is possible to advantageously incorporate the vehicle air conditioning system into the cooling circuit. For example, the waste heat of the drive system or one or more drive components can be used to heat the interior of the vehicle.

[0026] The object stated at the beginning is also achieved by an electric vehicle comprising a drive system having one or more of the above-described aspects. In this regard, for the advantages, reference is made to the description of the drive system.

[0027] The means described in connection with the drive system and / or further explained below serve for a further improvement of the electric vehicle.

[0028] From the following description and the drawings, further advantageous configurations will become apparent.

Brief Description of the Drawings

[0029] [Figure 1] It is a basic circuit diagram of the drive system. [Figure 2] It is a partial side cross-sectional view of the drive system. [Figure 3] It is a schematic diagram of the configuration of a drive system having a plurality of drive modules.

Modes for Carrying Out the Invention

[0030] FIG. 1 schematically shows a basic circuit diagram of a drive system 10 for an electric vehicle 100. FIG. 1 also shows an electric vehicle 100 comprising such a drive system 10. The drive system 10 is described below.

[0031] The drive system 10 comprises, as drive components, a traction battery 12, an inverter 14, and an electric machine 16. The traction battery 12 is electrically connected to the electric machine 16 via the inverter 14. The inverter 14 has a DC voltage side 18 and an AC voltage side 20. The traction battery 12 is electrically connected to the inverter 14 by means of high voltage connection elements 22, 24 respectively, and the inverter 14 is electrically connected to the electric machine 16.

[0032] The drive system 10 preferably has a cooling circuit 26 for cooling the drive components with a liquid cooling medium 28, where the drive components (traction battery 12, inverter 14, electromechanism 16) and high-voltage connection elements 22, 24 are each formed to transport the cooling medium, and together they form part 30 of the cooling circuit 26.

[0033] The drive components (traction battery 12, inverter 14, electromechanism 16) and high-voltage connection elements 22 and 24 each have a power conduction or current conduction line core L and a channel section K for transporting a cooling medium 28. The line core L and the channel section K extend adjacent to each other, and in particular in parallel, through the traction battery 12, high-voltage connection element 22, inverter 14, high-voltage connection element 24, and further through the electromechanism 16.

[0034] In this example, the high-voltage connection element 22 is formed as a multi-wire high-voltage line (not shown). The high-voltage connection element 24 can be formed as a multi-wire high-voltage line, a plug connector, a busbar, or a screw (not shown).

[0035] As already shown, each of the high-voltage connection elements 22, 24 has a power conduction or current conduction line core L and a channel section K for transporting the cooling medium 28. To form the channel section K, each of the high-voltage connection elements 22, 24 has a sheath surrounding the outside of each of the high-voltage connection elements 22, 24, and the channel section K for the cooling medium 28 (not shown) is formed in the intermediate space between the sheath and the high-voltage connection elements 22, 24 or the line core L.

[0036] The drive component and the high-voltage connection elements 22 and 24 each have connection interfaces 32 and 34 for coupling the drive component to the high-voltage connection elements 22 and 24 (shown only once in Figure 1 for clarity), and the connection interfaces 32 and 34 each have an electrical connection (for power or current conduction) and a fluid connection (for transporting the cooling medium 28) (not shown).

[0037] Preferably, some of the drive components and high-voltage connection elements 22, 24, or all of the drive components (traction battery 12, inverter 14, electromechanism 16) and high-voltage connection elements 22, 24, can be cooled by the cooling medium 28 by direct cooling. Therefore, the cooling medium 28 can flow directly around areas or regions that have particularly high cooling requirements.

[0038] In this example, a cooler or heat exchanger 36 for controlling the temperature of the cooling medium 28 is connected upstream of the traction battery 12 in the cooling circuit 26 or in the circulating direction U of the cooling circuit 26 or the cooling medium 28.

[0039] In this example, the drive system 10 may have a gear mechanism 40 as a further drive component, coupled to the electromachine 16 and connected downstream of the electromachine 16 (see Figure 2), the gear mechanism 40 having a gear mechanism heat exchanger 42, the gear mechanism heat exchanger 42 being incorporated into the cooling circuit 26 (see Figure 1). In this example, the gear mechanism heat exchanger 42 is connected downstream of the electromachine 16 in the circulating direction of the cooling circuit 26 or the cooling medium 28.

[0040] In this example, a pump 44 for transporting the cooling medium 28 is connected upstream of the traction battery 12 in the cooling circuit 26, and in particular, directly upstream. In this example, an additional pump 46 for transporting the cooling medium 28 is connected upstream of the electromechanical unit 16 in the cooling circuit 26.

[0041] In this example, the illustrated cooling circuit 26 is the only cooling circuit for the drive system 10. The drive components (traction battery 12, inverter 14, electromechanism 16, gear mechanism 40) and the electrical high-voltage connection elements 22, 24 are all incorporated into the cooling circuit 26 and are therefore temperature-controlled or cooled by the cooling circuit 26. In this example, the cooling circuit 26 has only one cooling medium 28.

[0042] Figure 2 shows a partial side cross-sectional view of the drive system 10, and for clarity, only the inverter 14, the electromechanism 16, the gear mechanism 40, and a portion of the cooling circuit 26 are shown.

[0043] The connection interface 34 is located on the DC voltage side 18 of the inverter 14, and the connection interface 34 has an electrical connection 50 or L (for power or current conduction) and a fluid connection 52 or K (for transporting the cooling medium 28). A further connection interface 34' having an electrical connection 50' and a fluid connection 52' is formed on the AC voltage side 20. A high-voltage connection element 24 is formed to the electrical connection 50' by, for example, a busbar. The cooling medium 28 is transported to the electromachine 16 via the fluid connection 52'.

[0044] The inverter 14 has a housing 54 with an upper closing cover 56. For example, a cooling structure 58 for the carrier plate and / or electrical components of the inverter 14's active components 60 is located inside the housing 54, and a cooling medium 28 flows through this cooling structure 58.

[0045] Similarly, the cooling medium 28 flows through the electromachine 16, entering the electromachine 16 at the inlet 62 and exiting the electromachine 16 at the outlet 64. The electromachine 16 may have a stator cooling system, for example, a direct stator cooling system. After exiting the outlet 64, the cooling medium 28 flows through the gear mechanism heat exchanger 42.

[0046] Figure 3 shows the configuration of the drive system 10, which has two inverters 14, 14', two electromechanisms 16, 16', and two gear mechanisms 40, 40' having gear mechanism heat exchangers 42, 42'. One inverter 14, 14', one electromechanism 16, 16', and one gear mechanism 40, 40' having gear mechanism heat exchangers 42, 42' are combined to form drive modules 70, 70'. Therefore, the drive system 10 has two drive modules 70, 70', and individual wheel drive can be achieved by the drive modules 70, 70'.

[0047] In this example, both drive modules 70, 70' are supplied with electrical energy by a traction battery 12. In this example, a charging line 80 (not shown) is connected to the traction battery 12, electrically connecting it to a charging socket in the electric vehicle 100. The charging line 80 is connected to a cooling circuit 26 and is therefore cooled. The charging line 80 has a current-conducting or power-conducting line core L and a channel section K for a cooling medium 28.

[0048] The cooling medium 28 (coming from, for example, the heat exchanger 36) enters the traction battery 12 at the inlet 82, flows through the traction battery, and is then divided into two substreams 84 and 86, each of which is supplied to the drive modules 70 and 70'.

[0049] High-voltage connection elements 22, 22', each having a current-conducting or power-conducting line core L and a channel section K for a cooling medium 28, electrically and fluidly connect the traction battery 12 to the inverters 14, 14' (DC voltage side 18).

[0050] Each substream 84, 86 flows through its respective drive module 70, 70', and in each case, the cooling medium 28 passes through the inverters 14, 14', the electromechanisms 16, 16', and the gear mechanism heat exchangers 42, 42'. In the inverters 14, 14', the cooling medium 28 flows through its respective cooling structures 58, 58'.

[0051] High-voltage connection elements 24, 24' that electrically connect inverters 14, 14' to electromechanisms 16, 16' are formed on the AC voltage side 20 by busbars. Thereafter, the cooling medium 28 is also transferred to the electromechanism 16 and used to cool the stators 17, 17'.

[0052] Subsequently, the cooling medium 28 exits the electromechanisms 16, 16' and is supplied in each case to the gear mechanism heat exchangers 42, 42' of the gear mechanism 40, 40'. After passing through the gear mechanism heat exchangers 42, 42', the two substreams 84, 86 of the cooling circuit 26 can be combined as needed to form a single stream which can then be supplied back to the heat exchanger 36.

[0053] As described above, one, more, or all of the drive components can be connected to the cooling circuit 26 by a controllable switching valve (not shown). Therefore, each drive component can be connected to or disconnected from the cooling circuit, depending on the cooling requirements.

[0054] Optionally, one or more heat exchange devices are provided, each having a first side incorporated into the cooling circuit 26 and a second side having a heat release connection for releasing thermal energy (not shown). Thus, the interior of the vehicle can be heated using the waste heat from one or more drive components. [Explanation of symbols]

[0055] 10 Drive System 12 Traction Batteries 14, 14' Inverter 16, 16' Electrical machinery 22, 22' High-voltage connection element 24, 24' High-voltage connection element 26 Cooling circuit 28 Cooling medium 30 Part of the cooling circuit 26 32, 34 Connection Interfaces 36 Heat exchanger 40, 40' gear mechanism 42, 42' Gear mechanism heat exchanger 44 pumps 46 pumps 50, 50' Electrical connection 52, 52' Fluid connection 70, 70' drive module 100 Electric Vehicles

Claims

1. A drive system (10) for an electric vehicle (100), comprising a traction battery (12), an inverter (14, 14'), and an electromechanism (16, 16') as drive components, wherein the traction battery (12, 12') is electrically connected to the electromechanism (16, 16') via the inverter (14, 14'), and the traction battery (12) is electrically connected to the inverter (14, 16') via high-voltage connection elements (22, 22'; 24, 24'), respectively. In a drive system (10) electrically connected to 14') and the inverter (14, 14') electrically connected to the electromechanism (16, 16'), the drive system (10) includes a cooling circuit (26) for cooling the drive components with a cooling medium (28), and the drive components and the high-voltage connection elements (22, 22'; 24, 24') are each formed to transport the cooling medium and form a part (30) of the cooling circuit (26), The traction battery (12), the inverter (14), the electromechanism (16), and the high-voltage connection elements (22, 24) each have a power conduction line core (L) and a channel section (K) for transporting the cooling medium (28), and the power conduction line core (L) and the channel section (K) extend through connection interfaces (32, 34) incorporating electrical and fluid connections for coupling each of the traction battery (12), the high-voltage connection element (22), the inverter (14), the high-voltage connection element (24), and the electromechanism (16), as well as the drive components (12, 14, 16), to each of the high-voltage connection elements (22, 22'; 24, 24'). The drive system (10) is characterized in that the channel section (K) is formed in the intermediate space between the sheath and the power conduction line core (L) at least in the portion from the traction battery (12) through the connection interface (34) to the inverter (14).

2. The drive system (10) according to claim 1, characterized in that some of the drive components and the high-voltage connection elements (22, 22'; 24, 24'), or all of the drive components and the high-voltage connection elements (22, 22'; 24, 24'), are formed to be coolable by the cooling medium (28) by direct cooling.

3. The drive system (10) according to claim 1 or 2, characterized in that a heat exchanger (36) for controlling the temperature of the cooling medium (28) is connected upstream of the traction battery (12) within the cooling circuit (26).

4. The drive system (10) according to any one of claims 1 to 3, further comprising the drive system (10) having at least one gear mechanism (40, 40') coupled to the electromechanism (16, 16'), the gear mechanism (40, 40') having a gear mechanism heat exchanger (42, 42'), and the gear mechanism heat exchanger (42, 42') being incorporated into the cooling circuit (26).

5. The drive system (10) according to claim 4, wherein the drive system (10) comprises at least two inverters (14, 14'), at least two electromechanisms (16, 16'), and at least two gear mechanisms (40, 40') having gear mechanism heat exchangers (42, 42'), and one inverter (14, 14'), one electromechanism (16, 16'), and one gear mechanism (40, 40') having gear mechanism heat exchangers (42, 42') are each combined to form a drive module (70, 70').

6. The drive system (10) according to any one of claims 1 to 5, characterized in that a pump (44) for transporting the cooling medium (28) is connected upstream of the traction battery (12) in the cooling circuit (26), and / or a pump (46) for transporting the cooling medium (28) is connected upstream of the electromechanical units (16, 16') in the cooling circuit (26).

7. The drive system (10) according to any one of claims 1 to 6, characterized in that the cooling circuit (26) is the only cooling circuit of the drive system (10), and / or the cooling circuit (26) has only one cooling medium (28).

8. The drive system (10) according to any one of claims 1 to 7, characterized in that one, more, or all of the drive components are connected to the cooling circuit (26) by controllable switching valves.

9. A drive system (10) according to any one of claims 1 to 8, characterized in that one or more heat exchange devices are provided, each having a first side of the heat exchange device incorporated into the cooling circuit (26), and a second side of the heat exchange device having a heat release connection for releasing thermal energy.

10. An electric vehicle (100) having a drive system (10) according to any one of claims 1 to 9.

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