Component layout configuration for DC-DC converter and vehicle high-voltage on-board electrical system

Abstract

The present invention relates to a DC-DC converter (8), which comprises a number of DC-DC converter modules with different electrical input and output voltages, which are designed as a common integrated component and can be electrically connected to each other as a number of subsystems (A, B, C) so as to be able to convert a high voltage into various low voltages.Furthermore, the present invention relates to a component arrangement (1) for a high voltage on-board electrical system of a vehicle.

Description

[Technical Field]

[0001] The present invention relates to a DC-DC converter and a component arrangement for a vehicle's high voltage on-board electrical system. [Background technology]

[0002] From the prior art, as described in Patent Document 1, a vehicle is known that has a high-voltage on-board electrical system. The high-voltage on-board electrical system is subdivided into two sub-areas, the first sub-area being arranged in a first design space of the vehicle and the second sub-area being arranged in at least one second design space of the vehicle. The sub-division of the high-voltage on-board electrical system into both sub-areas is configured so that in the first design space of the vehicle, operation is only possible under the voltage of the first sub-area of ​​the high-voltage on-board electrical system, and in the at least one second design space of the vehicle, operation is possible when there is no voltage in the second sub-area of ​​the high-voltage on-board electrical system.

[0003] Patent Document 2 describes disposing at least one high-voltage battery having a plurality of storage cells electrically connected to one another and configured to store electrical energy in a monocoque body of a passenger vehicle. The high-voltage battery and high-voltage components provided in addition to the high-voltage battery and electrically connected to the high-voltage battery are at least indirectly supported by the body. The body forms a high-voltage safety cell whose temperature can be controlled by a temperature control device of the passenger vehicle, and the high-voltage battery and other high-voltage components are disposed therein.

[0004] Patent Document 3 discloses an electrical on-board electrical system for a motor vehicle. The system includes at least one first and one second potential line, and is configured such that a DC voltage is applied between the potential lines during application. The on-board electrical system has at least one Y-capacitor electrically coupled to one of the potential lines by a first connection and to a reference potential by a second connection. A switching element is connected in parallel to the at least one Y-capacitor.

[0005] Patent Document 4 describes a vehicle having a high-voltage on-board electrical system that is subdivided into three sub-areas, with a first sub-area being arranged in a first design space of the vehicle, a second sub-area being arranged in a second design space of the vehicle, and a third sub-area being arranged outside both of these design spaces of the vehicle. Patent Document 5 describes an on-board electrical system for a vehicle, a vehicle having the on-board electrical system, and a method for operating the on-board electrical system for a vehicle. The on-board electrical system includes a battery having two battery potential contacts and a vehicle-side DC charging connection having two charging potential contacts. A DC-DC converter is provided. The first battery potential contact is electrically connectable or coupled to a first potential contact on the output side of the DC-DC converter. The second battery potential contact is electrically connectable or coupled to a second charging potential contact. Each charging potential contact is electrically connectable or coupled to a respective potential contact on the input side of the DC-DC converter. The second potential contact on the output side of the DC-DC converter is electrically connectable or coupled to a first potential contact on the input side of the DC-DC converter. The potential contacts on the input side of the DC-DC converter are each electrically connected to a connection contact of a first capacitor. The potential contacts on the output side of the DC-DC converter are each electrically connectable or coupled to a connection contact of a second capacitor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE102019008835A1 [Patent Document 2] DE102018004498A1 [Patent Document 3] DE102018002926A1 [Patent Document 4] DE102019008825A1 [Patent Document 5] DE102021003831 Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved DC-DC converter compared to the prior art, and an improved component arrangement for a high voltage on-board electrical system of a vehicle compared to the prior art. [Means for solving the problem]

[0008] This problem is solved according to the invention by a DC-DC converter having the features of claim 1 and also by a component arrangement for a high-voltage on-board electrical system of a vehicle having the features of claim 5.

[0009] Advantageous embodiments of the invention are the subject of the dependent claims.

[0010] According to the present invention, a DC-DC converter, particularly for a vehicle, comprises a plurality of DC-DC converter modules with different electrical input and output voltages, which are designed as a common integrated component, in particular in a common converter housing, and are electrically connectable to one another as a plurality of subsystems so as to be able to convert a high voltage into a variety of low voltages. DC-DC converters are also called DC / DC converters, and because a high voltage is converted into a plurality of low voltages, they are also called LV-DC / DC converters.

[0011] In particular, one DC-DC converter module is provided for converting a high voltage to a low voltage, and another DC-DC converter module is provided for converting a low voltage to another low voltage, and this other DC-DC converter module can be coupled to, for example, a DC-DC converter module that converts a high voltage, thereby converting the low voltage of the DC-DC converter module to another low voltage, or can be coupled to the output side of yet another DC-DC converter module, thereby converting the low voltage of the DC-DC converter module to another low voltage.

[0012] Thus, the DC-DC converter according to the invention is designed modularly and can therefore perform multiple tasks, in particular supply or couple to multiple low-voltage vehicle electrical systems, for example wiring different voltage levels of 12V and 48V simultaneously and thus switching different subsystems on or off internally.

[0013] The DC-DC converter according to the present invention can be applied, for example, in a component arrangement for a high-voltage on-board electrical system of a vehicle. The component arrangement according to the present invention therefore includes such a DC-DC converter. This component arrangement is also called a converter box. In this component arrangement, a common EMC filter (EMC = electromagnetic compatibility) and a common intermediate circuit are provided for multiple components, and these electrical components are arranged together with the common EMC filter and common intermediate circuit in a common housing. The electrical components provided with the common EMC filter and common intermediate circuit are, in particular, power electronics, a rectifier, and / or a DC-DC converter for at least one electric drive machine for driving the vehicle. In this component arrangement, preferably, all major components of the high-voltage system are arranged and interconnected in a box, i.e., a common housing, so that this box is particularly identical and advantageously universally usable. Therefore, each component of this component arrangement is also universal. In the example described here, this applies in particular to a DC-DC converter that can fulfill multiple roles and operate multiple low-voltage on-board electrical systems.

[0014] The DC-DC converter can preferably meet all requirements simultaneously. Individual functions can be activated or deactivated, for example, by software and / or switches. Therefore, the DC-DC converter, and preferably also the component arrangement, can be used for all possible requirements, especially in the same configuration, and can be adjusted in the application software or by the application to achieve the desired functions.

[0015] The housing of the component arrangement is preferably provided with all necessary low-voltage connections and is electrically connected or connectable to the DC-DC converter, and for each intended use of the component arrangement, the unused low-voltage connections are then closed, for example by a cover.

[0016] In particular, in order to adapt to the various possible functions described above and to the various low voltages required therefor, as well as to the various required outputs, it is advantageous for the subsystems of the DC-DC converter to be activatable and deactivatable independently of one another, with at least one of the subsystems being intended to be active at all times. This allows for a simplified construction, since not all subsystems of the DC-DC converter need to be deactivatable.

[0017] As explained above, a DC-DC converter module is constructed as a common integrated design unit, particularly within a common converter housing, and is therefore not simply a parallel circuit of multiple DC-DC converters.

[0018] As an alternative to the use of the DC-DC converter described above in a component arrangement also referred to as a converter box, for example the DC-DC converter may be intended as a separate assembly, external to such a component arrangement or directly connected to the high voltage system without such a component arrangement.

[0019] Nevertheless, if the EMC filters and intermediate circuits of the independent assemblies are not jointly utilized, the need to ensure EMC compatibility and intermediate circuits with the high voltage system means that in most cases the independent assemblies will have their own EMC filters and intermediate circuits attached to the assembly, which may in particular be housed in the housing of the assembly.

[0020] Due to its modular design, the DC-DC converter according to the invention allows for the cost-effective construction of several low-voltage on-board electrical systems, which is particularly necessary in electric vehicles for the operation of safety-critical functions and for the simultaneous operation of different consumers and suppliers in separate low-voltage on-board electrical systems.

[0021] The DC-DC converter modules preferably each have a low output power. As explained above, the DC-DC converter modules are used for different low-voltage vehicle electrical systems. When a relatively high low-voltage output is required, several DC-DC converter modules or subsystems are connected in parallel on the output side, thereby enabling efficient operation at partial loads.

[0022] As already mentioned, the DC-DC converter of the present invention enables cost reduction by utilizing a single module system for different functions in low-voltage voltage conversion, and efficiency improvement by accurately shutting down one or more subsystems in each low-voltage onboard electrical system under low low-voltage loads, since the DC-DC converter has its maximum efficiency at its rated operating point. The DC-DC converter of the present invention also enables simple fabrication of multiple low-voltage onboard electrical systems in a vehicle. Furthermore, it eliminates the need to develop a new DC-DC converter to accommodate changes in functional requirements, such as when the onboard electrical system requirements increase or an additional converter is needed for a solar roof.

[0023] Furthermore, the DC-DC converter according to the present invention has the advantage that it can be used to generate safe low voltage voltages in safety-critical applications, for example for highly automated driving and steer-by-wire.

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0025] [Figure 1] 1 shows a schematic diagram of a DC-DC converter. [Figure 2] 1 illustrates a schematic of a component layout for a vehicle's high voltage on-board electrical system. DETAILED DESCRIPTION OF THE INVENTION

[0026] In all the drawings, the same reference numerals are used to designate corresponding parts.

[0027] 1 shows a schematic diagram of an embodiment of a DC-DC converter 8, particularly for a vehicle, which comprises a number of DC-DC converter modules with different electrical input and output voltages, which are designed as a common integrated component, particularly in a common converter housing 10, and which can be electrically connected to one another as a number of subsystems A, B, C, so as to be able to convert a high voltage into various lower voltages.

[0028] In this way, the DC-DC converter module can be electrically wired to allow connection of multiple low-voltage on-board electrical systems, particularly with different low-voltage voltages, in an electric vehicle having a high-voltage battery 7.

[0029] In the illustrated example, the DC-DC converter 8 is used in this manner for a low-voltage onboard electrical system 11 having a first low-voltage voltage level, for example for consumers and a low-voltage battery, a low-voltage onboard electrical system 12 having a different second low-voltage voltage level, for example for further consumers and a further low-voltage battery, an energy recovery unit 13 for example for a solar module and / or a damper system, and a self-supply unit 14 for low-voltage components, in particular in the high-voltage electrical / electronics installation space.

[0030] The DC-DC converter 8 is also called a DC / DC converter, and is also called an LV-DC / DC converter because it converts a high voltage into a plurality of low voltages.

[0031] The subsystems A, B, C are based in particular on the electrical wiring of the DC-DC converter modules by bus bars, for example also called rails, although electrical wiring by cables is also possible.

[0032] The solution described above is thus a modular DC-DC converter 8 for converting a high voltage voltage into various low voltage voltages that can be used in vehicles, in particular configured as electric vehicles.

[0033] In particular, one DC-DC converter module is provided for converting a high-voltage voltage to a low-voltage voltage, and another DC-DC converter module is provided for converting a low-voltage voltage to another low-voltage voltage, and this other DC-DC converter module can be coupled to, for example, a DC-DC converter module that converts a high-voltage voltage, thereby converting the low-voltage voltage of the DC-DC converter module to another low-voltage voltage, or can be coupled to the output side of yet another DC-DC converter module, thereby converting the low-voltage voltage of the DC-DC converter module to another low-voltage voltage.

[0034] In this way, the first DC-DC converter module converts a high voltage, for example 800 V, into a low voltage, for example 48 V, particularly while maintaining galvanic isolation. If a lower low voltage is required, for example 12 V, this low voltage can be generated by another, particularly galvanically coupled DC-DC converter module. To this end, both DC-DC converter modules are electrically connected to each other to form subsystems A, B, and C. The first DC-DC converter module for converting the high voltage can, by way of example, already form its own subsystems A, B, and C. In the example described by way of example, the DC-DC converter 8 has subsystems A, B, and C with a high voltage as input voltage and a high low voltage as output voltage, and further subsystems B, C, and A with a high voltage as input voltage and a low low voltage as output voltage. In the example shown in FIG. 1, three subsystems A, B, and C are provided, each of which may be configured in the manner described above or with DC-DC converter modules electrically coupled to each other.

[0035] Advantageously, each subsystem A, B, C is connected on the output side with an EMC filter 9, which will be referred to below as further EMC filter 9, particularly in connection with FIG.

[0036] The DC-DC converter module can advantageously operate bidirectionally, thereby enabling pre-charging of the vehicle's high voltage on-board electrical system.

[0037] The individual DC-DC converter modules are specifically designed for a low power rating of, for example, 500W.

[0038] In one possible embodiment, the first DC-DC converter module, i.e., a DC-DC converter module for converting a high-voltage voltage into a high low-voltage voltage, for example 48 V, is designed for functionally reliable and safe operation. In that case, this DC-DC converter module additionally comprises an integrated short-circuit-protected disconnect on the high-voltage side, which additionally meets functional requirements and achieves a high ASIL level, for example for ASIL D. This allows this DC-DC converter module to be connected directly, in particular without a contact breaker, to the high-voltage battery 7 and to be used for safety-critical functions, for example for steer-by-wire or highly automated driving functions, without an additional low-voltage battery.

[0039] As shown in Figure 1, the individual subsystems A, B, and C are electrically connected in parallel on the high-voltage side, i.e., on the input side. In this way, as already mentioned above, multiple low-voltage onboard electrical systems can be generated on the low-voltage side.

[0040] If the required low-voltage vehicle electrical system output exceeds the output provided by each subsystem A, B, C, it is advantageous to connect multiple subsystems A, B, C in parallel on both the output side, i.e., on the low-voltage side. If the load changes during operation, the individual subsystems A, B, C can be switched on or off again depending on the load case. This ensures that each individual operating subsystem A, B, C operates efficiently even under low low-voltage loads.

[0041] The DC-DC converter 8 enables cost reduction by using one modular system for different functions in low-voltage voltage conversion, and efficiency improvement by accurately shutting down one or more subsystems A, B, and C under low low-voltage loads in each low-voltage onboard electrical system, because the DC-DC converter 8 has its maximum efficiency at its rated operating point. The DC-DC converter 8 also enables easy manufacturability of multiple low-voltage onboard electrical systems in a vehicle. Furthermore, new DC-DC converter development is not required when functional requirements change, for example, when onboard electrical system requirements increase or additional converters are needed for a solar roof.

[0042] Furthermore, the DC-DC converter 8, as explained above, can be advantageously used to generate safe low voltage voltages in safety-critical applications, for example for highly automated driving and steer-by-wire.

[0043] The DC-DC converter 8 can be applied in a component arrangement 1 for a high-voltage on-board electrical system of a vehicle, for example, as shown in FIG. 2 by way of example.

[0044] In this component arrangement configuration 1, a common EMC filter 2 and a common intermediate circuit 3 are provided for a plurality of electrical components K, and the electrical components K are arranged together with the common EMC filter 2 and the common intermediate circuit 3 in a common housing 4.

[0045] The common intermediate circuit 3 is configured, for example, as a capacitor.

[0046] The unit with the housing 4 and with the electrical components K, the common EMC filter 2 and the common intermediate circuit 3 contained therein is also called a converter box.

[0047] This solution allows for a simplified and uniform construction of the vehicle's high-voltage system, since various electrical components K can share a common intermediate circuit 3 and a common EMC filter 2, which are designed to perform the functions for all of these components K. In this way, the components K themselves do not have to have their own EMC filters or intermediate circuits and can be made smaller and more compact. Thus, in this solution, all the main components of the high-voltage system for a vehicle are advantageously arranged and connected to one another in one housing 4, i.e., in one box, which is of particularly uniform construction and can be universally used for a variety of vehicles, especially for different vehicle models.

[0048] The electrical components K in which the common EMC filter 2 and the common intermediate circuit 3 are provided are, by way of example, power electronics 5 for at least one electric drive machine for driving the vehicle, in particular a rectifier 6, also known as an AC / DC converter, for AC charging of the vehicle's high-voltage battery 7, and a DC-DC converter 8, as shown in FIG. 2 .

[0049] The power electronics 5 for the at least one electric drive machine have a galvanic coupling, and the rectifier 6 and the DC-DC converter 8 each have a galvanic isolation.

[0050] Optionally, provision can be made for a further EMC filter 9 to be arranged at the output of each component K, i.e. one, several or all of the components K may have their own separate EMC filter 9 at their output. Each separate EMC filter 9 can then be arranged, for example, in a common housing 4. In the illustrated example, such separate EMC filters 9 are shown for the power electronics 5 and the rectifier 6. Since the DC-DC converter 8 has several outputs, a separate EMC filter 9 can be provided at each output, i.e. at one or several outputs or at all outputs.

[0051] In another possible embodiment, instead of a separate component K for the rectifier 6, also called an AC / DC converter, for AC charging of the high-voltage battery 7, the frequency converter of the power electronics 5 for the at least one electric drive machine can also be configured to perform this function. The AC charging function and the machine inverter function, also called an inverter or frequency converter, are implemented here, particularly by semiconductor circuits. In this embodiment, the output of the power electronics 5 for the at least one electric drive machine is provided with a safety unit, preferably arranged in the direction of the AC charging connection for implementing the AC charging function, between the power electronics 5 for the at least one electric drive machine and a separate EMC filter 9. This safety unit is used to ensure compliance with safety and EMC standards. Galvanic coupling requires additional measures, such as an emergency stop or neutralization of PE leakage currents.

[0052] In another embodiment, for example, the AC charging function may not be integrated, in which case the only components K sharing the common intermediate circuit 3 and the common EMC filter 2 are the power electronics 5 and the DC-DC converter 8 for at least one electric drive machine.

[0053] As mentioned above, the above-mentioned components K share a common intermediate circuit 3 and a common EMC filter 2 on the DC side. They furthermore have a separable output to the high-voltage battery 7 in the illustrated example. The separating elements 15 for this are configured, for example, as semiconductor fuses or contactors / CSIDs, respectively. Here, for example, one semiconductor fuse in each case can be provided on both poles, or a contactor / fuse combination in each case on both poles, or one contactor / CSID in each case on both poles, or one contactor in one pole and one semiconductor fuse in the other pole.

[0054] The components K are in particular each configured as a semiconductor component.

[0055] Additionally, a microcontroller may be provided which is also arranged in the housing 4. This microcontroller is also in particular designed as a semiconductor component.

[0056] The common intermediate circuit 3 and the common EMC filter 2 are each constructed in particular as passive components.

[0057] The separating elements 15 are in particular configured as passive semiconductor components, for example as semiconductor fuses, or alternatively, they can be embodied as contactors or CSIDs, which are mechanical components in contrast to the above.

[0058] Each further EMC filter 9, if provided, is configured in particular as a passive component.

[0059] The components of the component arrangement 1 described above, in particular the converter box and in particular the component K described above, which are arranged in the housing 4, are jointly embodied in the form of highly integrated power electronics, i.e. the component arrangement 1 does not have individual components in the housing 4 but rather highly integrated power electronics.

[0060] The above-described solution allows for compact integration of high voltage functionality such as electrical switching, charging, conversion, frequency conversion, etc., which also allows for e.g. a more compact design and / or reduced costs.

[0061] The above-described solution advantageously utilizes a common design space for all high-voltage functionalities, in particular for switching, charging, conversion, and frequency conversion. Synergies are exploited by jointly utilizing passive components such as a common EMC filter 2 and intermediate circuit capacitance, i.e., a common intermediate circuit 3. This allows for a compact design. Mechanical fuse / disconnect elements, in particular contactors, are replaced by semiconductor switches for isolation from the high-voltage battery 7, eliminating the need for mechanical components for the switching functions. Power electronic semiconductors are used to implement all core functions, in particular switching, conversion, charging, and frequency conversion.

[0062] Since all major functions are implemented in semiconductors in this way, a high degree of semiconductor integration can be achieved. Functional variations and / or additional functions, for example, based on special features, such as AC charging, can be implemented not through hardware changes as in the past, but advantageously through software, since individual functions cannot be removed from the entire high-voltage power electronics. Furthermore, this also allows functions to be purchased and released after the vehicle has been manufactured.

[0063] In order to be able to use a common EMC filter 2 for all functionality, the control of the individual semiconductor groups is coordinated with one another.

[0064] As already mentioned, the above-described solution advantageously utilizes a common installation space for all high-voltage functionalities, particularly switching, charging, conversion, and frequency conversion. In an embodiment in which the function of the rectifier 6 for AC charging of the high-voltage battery 7 is performed by a frequency converter in the power electronics 5 for at least one electric drive machine, thereby eliminating the need for a separate rectifier 6, synergies in passive components are utilized, as well as semiconductor circuits for the motor control and AC charging functionality. In addition to synergies in passive components, synergies at the semiconductor circuit level are also utilized for the motor control and AC charging functionality. This additional utilization of synergies in the drive converter and active components for AC charging allows for a more compact design and additional cost savings. The merging of different functions, particularly the AC charging function and the driving function of at least one electric drive machine, into a higher-level energy conversion function is a consistent development of the trend toward higher integration in the field of secondary battery-powered vehicles and takes into account semiconductor development trends. [Explanation of symbols]

[0065] 1 Component placement configuration 2 Common EMC filters 3 intermediate circuit 4. Housing 5. Power Electronics 6 Rectifier 7 High Voltage Battery 8 DC-DC converters 9. Another EMC filter 10 Converter housing 11 Low-voltage vehicle electrical system having a voltage level of a first low voltage 12 Low-voltage vehicle electrical system having a second low-voltage voltage level 13 Energy recovery section 14 Self supply section 15 Separation member A, B, C Subsystems K Component

Claims

1. A DC-DC converter (8), The DC-DC converter (8) comprises a plurality of DC-DC converter modules having the same electrical input voltage and different output voltages, the plurality of DC-DC converter modules being electrically connectable to one another on the input voltage side, and one of the DC-DC converter modules having a plurality of subsystems (A, B, C) for converting a high voltage voltage into a low voltage voltage, and another of the DC-DC converter modules having a plurality of other subsystems (A, B, C) for converting a high voltage voltage into a different low voltage voltage, so that the DC-DC converter can convert a high voltage voltage into a different low voltage voltage; The DC-DC converter (8), wherein the plurality of DC-DC converter modules are designed as integrated components in a common converter housing (10), and at least one of the plurality of subsystems (A, B, C) is always active.

2. A DC-DC converter (8) according to claim 1, characterized in that the plurality of subsystems (A, B, C) are operable and de-operable independently of each other.

3. A component arrangement (1) for a high-voltage on-board electrical system of a vehicle, said component arrangement (1) comprising a DC-DC converter (8) according to claim 1 or 2.

4. 4. The component arrangement (1) according to claim 3, characterized in that a common EMC filter (2) and a common intermediate circuit (3) are provided for a plurality of electrical components (K), and these electrical components (K) are arranged together with the common EMC filter (2) and the common intermediate circuit (3) in a common housing (4).

5. 5. The component arrangement (1) according to claim 4, characterized in that the electrical components (K) provided with the common EMC filter (2) and the common intermediate circuit (3) are power electronics (5), a rectifier (6) and the DC-DC converter (8) for at least one electric drive machine for driving the vehicle.

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