High-voltage connection device and high-voltage battery system for high-voltage battery of electric vehicle
By designing a high voltage bonding device for electric vehicles, the problem of limited availability when charging on 400V-EVSE is solved, 800V and 400V charging compatibility and complete redundancy of HV power supplies is achieved, and the availability and efficiency of the system is improved.
Patent Information
- Application Number
- CN202380072246.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-10-13
- Filing Date
- 2023-09-26
- Publication Date
- 2025-05-16
AI Technical Summary
The existing 800V battery system has limited availability when charged on 400V-EVSE, lacks a topology that provides redundant HV power supplies, and cannot provide fully redundant driving functions in autonomous driving mode.
A high voltage bonding device is designed to provide charging compatibility of 800V and 400V by connecting two battery packs in series or in parallel, and to provide full redundancy at the HV power supply, reducing the number of passive components for increased efficiency.
It achieves lower cost compatibility in 800V and 400V charging modes, provides complete redundancy of HV power supplies, improves system availability and efficiency, and is suitable for autonomous vehicles.
Smart Images
Figure CN120018976A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a high voltage (HV) battery engagement device for an electric vehicle. The present disclosure also relates to an HV battery system including the HV engagement device and a method and apparatus for operating the HV battery system. Furthermore, the present disclosure relates to a computer program and a computer readable medium. Background Art
[0002] In the battery transportation market, there are clear trends and strong demands:
[0003] a) Reduce charging time,
[0004] b) increase availability in the event of component failure (fail-safe system),
[0005] c) Reduce system cost,
[0006] d) Increase efficiency during driving and charging,
[0007] e) maximize mileage,
[0008] f) Provide flexible platform solutions.
[0009] The current solution to reduce charging time (a) is to increase the battery voltage in vehicles from 400V to 800V. 800V technology is also an important contributor to increasing efficiency (d), maximizing driving range (e) and reducing system cost (c).
[0010] In the present disclosure, the terms "800V" and "400V" represent a certain voltage range. The term "400V" is used for a voltage range from 60V to 500V. The term "800V" is used for a voltage range from 500V to 1000V.
[0011] One disadvantage of the "800V" topology is the limited availability of "800V" DC charging stations at present. Since the number of "800V"-EVSE (Electric Vehicle Supply Equipment) will only increase slowly in the coming years, there is a strong need to provide technical solutions for enabling "800V" vehicles to also be charged on "400V"-EVSE.
[0012] FIG. 1 shows an “800V” battery system for a battery electric vehicle 100 . The battery system 101 of the vehicle 100 includes a power distribution unit (PDU) 102 , a battery management system (BMS) 103 and a battery having two battery packs 104 , 106 . All HV loads (such as the main axle drive 108 and the redundant axle drive 110 , the main DC / DC converter 112 and the redundant DC / DC converter 114 for the 14V on-board grid power supply, and the HV auxiliary load 116 ) are operated at “800V”. The battery packs 104 , 106 of the battery are connected in series. Each battery pack 104 , 106 includes a series-connected battery cell and a parallel-connected battery cell. An overcurrent protection element 118 (e.g., a fuse or a high-temperature fuse) is located between the two battery packs 104 , 106. The protection element is a standard functional safety measure to protect the battery cell from overcurrent. The PDU includes a protection element and two contactors for each HV load.
[0013] Redundant axle drives and redundant HV / 14V-DCDC converters are optional configurations and are typically used to provide better driving performance and provide more comfort functions at the 14V level. However, this topology cannot provide full redundancy in the drive functions required for autonomous driving, even with a second axle drive and a second HV / 14V-DCDC. The reason for this is the lack of redundancy in the HV power supply.
[0014] Autonomous vehicles require topological solutions that can also provide drive functions in the event of powertrain defects. In this "limp home" mode, a reduction in driving performance and comfort is acceptable. The main requirement for this is redundancy in the battery system, as it represents the energy supply for all relevant functions such as (axle) drives, cooling and on-board power supply. In addition to redundancy in the HV energy supply, redundant drive systems and 14V supplies are also required to provide full redundancy for the drive.
[0015] In autonomous vehicles, the battery system is divided into several main battery packs (BPs). Typically, it is either divided into two BPs with the same voltage and capacity, each 50%, or two BPs with the same capacity and voltage, each 50%. If one BP becomes defective, the other BP can provide the energy needed to limp home.
[0016] FIG. 2 shows an “800V” battery system for a battery electric vehicle 200 that can provide compatibility with “400V” and “800V” electric vehicle supply equipment (EVSE). The “800V” battery is divided into two “400V” battery packs 204, 206. The two battery packs 204, 206 have the same number of cells. The battery circuit arrangement includes a battery switch matrix 220. The battery switch matrix 220 includes three switches CT1.1, CT1.2, and CT1.3. Using switches CT1.1, CT1.2, CT1.3, the battery packs 204, 206 can be connected in series for “800V” drive and “800V” DC charging, or connected in parallel for “400V” DC charging. The standard configuration is a series connection of two battery packs 204, 206, where all HV loads are operated at “800V”.
[0017] Compared to the standard “800V” topology shown in FIG. 1 , the “800V” battery circuit arrangement of FIG. 2 additionally includes a battery switch matrix 220 having battery switches CT1.1, CT1.2, and CT1.3, a second overcurrent protection element 221 (e.g., a high-temperature fuse), and a second battery current sensor 223.
[0018] All HV loads are usually operated at "800V". Battery switches CT1.1, CT1.2, CT1.3 can be used to connect battery packs in series (battery voltage is "800V"), in parallel (battery voltage is "400V"), or disconnect defective battery packs 204, 206. In this case, the remaining battery voltage is "400V".
[0019] The topology shown in Figure 2 allows two different DC charging modes:
[0020] Mode 1: “800V”-S charging (two BPs in series)
[0021] Mode 2: “400V”-P charging (two BPs in parallel)
[0022] "800V"-S charging is the standard charging mode. It provides the highest charging performance and therefore the shortest possible charging time. "400V"-P charging can achieve very high charging performance even at "400V"-EVSE, but this mode requires balancing the battery packs 204, 206 to prevent high inrush currents through the battery switches CT1.2 and CT1.3.
[0023] It is an object of the present disclosure to provide a more flexible and / or more efficient high voltage engagement device for electric vehicles, which can be provided at a lower cost. Summary of the invention
[0024] The above mentioned objects are achieved by the features of the independent claims. Advantageous embodiments are given in the dependent claims.
[0025] According to a first aspect, the above-mentioned purpose is achieved by a high voltage (HV) engagement device for a high voltage battery of an electric vehicle. The high voltage battery includes a first battery pack and a second battery pack connected in series. The first battery pack and the second battery pack each include a first battery pack terminal and a second battery pack terminal. The connection that interconnects the second battery pack terminal of the second battery pack and the first battery pack terminal of the first battery pack is free of any contactors and relays. In the connection that interconnects the second battery pack terminal of the second battery pack and the first battery pack terminal of the first battery pack, a first overcurrent protection device associated with the first battery pack and a second overcurrent protection device associated with the second battery pack can be arranged, wherein each of the overcurrent protection devices may include a fusible current cutout or a high temperature fuse. Alternatively, the first overcurrent protection device and the second overcurrent protection device may be arranged in the HV engagement device in the negative power supply line of the first battery pack and the positive power supply line of the first battery pack, respectively. The first overcurrent protection device may include a current sensor and / or a voltage sensor, and may be configured to measure the current through the first battery pack and / or the voltage at the output end of the first battery pack. Additionally, the second overcurrent protection device may include a current sensor and / or a voltage sensor, and may be configured to measure a current through the second battery pack and / or a voltage at an output terminal of the second battery pack, respectively.
[0026] The HV joining device includes a first battery terminal for connecting to a first battery pack terminal of the second battery pack and a second battery terminal for connecting to the second battery pack terminal of the first battery pack.
[0027] In addition, the HV junction device includes a high voltage output terminal having a first high voltage load terminal and a second high voltage load terminal for connecting a high voltage load group having one or more high voltage loads. The high voltage output terminal may include several connectors connected in parallel for connecting several high voltage loads so that the high voltage loads are connected in parallel.
[0028] The HV engagement device also includes a high voltage input having a first high voltage charging terminal and a second high voltage charging terminal for connecting to electric vehicle power supply equipment.
[0029] The HV engagement device includes a first contactor and a second contactor, and the first battery terminal is connected to the first high voltage charging terminal via the first contactor, and the second battery terminal is connected to the second high voltage charging terminal via the second contactor.
[0030] In addition, the HV engagement device includes a third contactor and a fourth contactor, and the first battery terminal is connected to the first high voltage load terminal via the third contactor, and the second battery terminal is connected to the second high voltage load terminal via the fourth contactor. The engagement device includes a fifth contactor and a sixth contactor and a node, which can be connected to the second battery terminal of the second battery pack and the first battery terminal of the first battery pack to provide a voltage level for the connection between the first battery pack and the second battery pack. The node is connected to the first high voltage charging terminal via the fifth contactor and is connected to the second high voltage charging terminal via the sixth contactor.
[0031] In this disclosure, a contactor is an electrically controlled switch for switching power circuits that provides electrical isolation.
[0032] HV joints offer the following advantages:
[0033] Fewer (only two) contactors are required to provide both “400V” charging and “800V” charging compatibility, and can therefore be provided at a lower cost.
[0034] • The HV engagement device provides full redundancy at the HV power source without additional components if one of the battery packs becomes defective.
[0035] The HV coupling arrangement allows a smaller number of passive components (particularly contactors) in the power circuit in both the “800V” driving and “800V” charging modes. Thus, high efficiency can be achieved.
[0036] The HV junction allows the combination of battery packs with different voltage levels and different cell technologies. This enables more and better expansion options for vehicle performance and total vehicle battery capacity and thus enables lower costs on the OEM side. In particular, the two battery packs do not require symmetrical installation spaces. The combination of different battery pack sizes in the vehicle enables the use of different installation spaces, which also leads to lower costs on the OEM side.
[0037] • During "800V" charging and "400V" charging, all HV components are continuously supplied with their nominal voltage. Compared to the topology shown in Figure 2, the HV engagement arrangement enables full performance of all HV auxiliary loads in all charging modes.
[0038] • The HV junction device is also suitable for charging topologies (much) greater than 1000V (eg 1500V) at a maximum 1000V charging station, in particular for commercial vehicles.
[0039] In at least one embodiment according to the first aspect, the HV coupling device includes a third battery terminal for connecting the second battery pack terminal of the second battery pack and a fourth battery terminal for connecting the first battery pack terminal of the first battery pack. In this case, the node is connected to the third battery terminal via the first overcurrent protection device and / or via the current sensor device or is directly connected to the third battery terminal. In addition, the node is connected to the fourth battery terminal via the second overcurrent protection device and / or the additional current sensor device or is directly connected to the fourth battery terminal. Using this topology, it is possible to connect battery packs to a junction box that are separate units, such as separately housed units. The connection interconnecting the second battery pack terminal of the second battery and the first battery pack terminal of the first battery pack can be part of the HV coupling device.
[0040] In at least one embodiment according to the first aspect, the HV junction device comprises a further battery terminal for connecting the second battery terminal of the second battery and the first battery terminal of the first battery. In this case, the node is directly connected to the further battery terminal. Using this topology, it is possible to connect the battery packs to a junction box, which are housed together in one unit, wherein, for example, each battery pack comprises a fusible cutout or a high temperature fuse.
[0041] In at least one embodiment according to the first aspect, the HV engagement device comprises at least one further high voltage output terminal having a first terminal and a second terminal, wherein the first battery terminal is connected to the first terminal of the further high voltage output terminal via a seventh contactor, and the second battery terminal is connected to the second terminal of the further high voltage output terminal via an eighth contactor. Thus, different HV loads or groups of HV loads can be connected to and disconnected from the high voltage battery independently of each other.
[0042] According to a second aspect, the above-mentioned purpose is achieved by a high-voltage battery system including a high-voltage battery for an electric vehicle. The high-voltage battery includes a first battery pack and a second battery pack connected in series. The first battery pack and the second battery pack each include a first battery pack terminal and a second battery pack terminal. In the connection that interconnects the second battery pack terminal of the second battery pack and the first battery pack terminal of the first battery pack, a first overcurrent protection device associated with the first battery pack and a second overcurrent protection device associated with the second battery pack are arranged, each of which includes a fusible current cutout or a high-temperature fuse. The connection that interconnects the second battery pack terminal of the second battery pack and the first battery pack terminal of the first battery pack is free of any contactors and relays. In addition, the HV battery system includes an HV coupling device according to the first aspect.
[0043] In at least one embodiment according to the second aspect, the first battery pack and the second battery pack have different numbers of battery cells.
[0044] In at least one embodiment according to the second aspect, the first battery pack and the second battery pack include different types of battery cells.
[0045] The advantageous embodiments of the first aspect are also valid for the second aspect.
[0046] According to the third and fourth aspects, the above-mentioned objects are achieved by a method and a corresponding device for operating a high voltage battery system according to the second aspect. During a charging mode, when the electric vehicle power supply equipment is connected to the first high voltage charging terminal and the second high voltage charging terminal and receives a high voltage direct current (DC) from the electric vehicle power supply equipment, the switching state of each of the first, second, fifth and sixth contactors is controlled so that the high voltage DC is alternately routed to the first battery pack and the second battery pack.
[0047] In at least one embodiment according to the third aspect and the fourth aspect, the switching frequency for alternating charging is selected according to the state of charge of the first battery pack and / or according to the state of charge of the second battery pack. In particular, the switching frequency for alternating charging can be adjusted to find the best compromise between a low number of switching events and an acceptable state of charge delta for the two battery packs.
[0048] According to a fifth aspect, the above mentioned object is achieved by a computer program comprising instructions which, when executed by a controller or a processor of a control unit of the HV battery system according to the second aspect, cause the control unit to perform the steps of the method according to the third aspect.
[0049] According to a sixth aspect, the above mentioned object is achieved by a computer readable medium having stored thereon the computer program according to the fifth aspect.The computer readable medium may be a non-volatile computer readable medium.
[0050] The advantageous embodiments of the third and fourth aspects are also valid for the fifth and sixth aspects.
[0051] In the context of this document, reference to such a computer program is synonymous with the term program elements and / or computer program product containing instructions for controlling a computer system to appropriately coordinate the operation of the system or method to achieve the effects associated with the method of the present invention.
[0052] The computer program may be implemented as a computer-readable instruction code in any suitable programming language (such as JAVA, C++, etc.). The computer program may be stored on a computer-readable storage medium (CD-ROM, DVD, Blu-ray disc, removable drive, volatile or non-volatile memory, built-in memory / processor, etc.). The instruction code may program a computer or other programmable device (such as a control unit for an engine of a motor vehicle, in particular) in a manner to perform the desired functions. In addition, the computer program may be provided on a network such as the Internet, from which it may be downloaded by a user as required.
[0053] The present disclosure is described in more detail below with reference to the accompanying drawings showing embodiments of the present disclosure. These and other aspects of the present disclosure will become more fully understood by reading the detailed description below. When browsing the following description of specific exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, other aspects, features and embodiments of the present disclosure will become apparent to those of ordinary skill in the art. Although the features of the present disclosure may be discussed relative to certain embodiments and drawings below, all embodiments of the present disclosure may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used according to the different embodiments of the present disclosure discussed herein. Similarly, although exemplary embodiments may be discussed below as device, system or method embodiments, it should be understood that such exemplary embodiments may be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 illustrates a battery system according to the prior art,
[0055] FIG. 2 illustrates another battery system according to the prior art,
[0056] Figure 3 A simplified exemplary circuit diagram of an embodiment of a high voltage battery system is illustrated,
[0057] Figure 4 The diagram shows the Figure 3 The energy flows and voltage levels of the HV battery system HVBS shown in,
[0058] Figure 5 Another simplified exemplary circuit diagram of an embodiment of a high voltage battery system is illustrated.
[0059] Figure 6 Illustration of a vehicle in limp home mode Figure 5 The energy flows and voltage levels of the high voltage battery system shown in
[0060] Figure 7Another simplified exemplary circuit diagram of an embodiment of a high voltage battery system is illustrated.
[0061] Figure 8a and Figure 8b The diagram shows the alternating charging mode. Figure 3 energy flows and voltage levels of high-voltage battery systems, and
[0062] Fig. 9 The diagram shows the alternating charging mode. Figure 7 Energy flow and voltage levels of high voltage battery systems. DETAILED DESCRIPTION
[0063] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, certain structures and components are shown in block diagram form in order to avoid obscuring such concepts.
[0064] exist Figures 3 to 9 In the present disclosure, the same reference numerals are used for elements having substantially the same function, but these elements do not necessarily need to be identical in all details.
[0065] Note that when an element is described as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or there may be intervening elements. Conversely, when an element is described as being "directly" "connected" or "coupled" to another element, there are no intervening elements. Other expressions used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).
[0066] Figure 3 A simplified exemplary circuit diagram of an embodiment of a high voltage (HV) battery system HVBS for an electric vehicle 100 , and in particular for a battery electric vehicle (BEV), is shown.
[0067] The HV battery system HVBS comprises an HV engagement device JD and a first battery pack BP1 and a second battery pack BP2. The HV engagement device JD provides "800V" charging and "400V" charging compatibility and full redundancy at the high voltage power supply (HV power supply) and optionally at the low voltage power supply (LV power supply) and the drive system.
[0068] Both battery packs BP1, BP2 include battery cells connected in series and in parallel. For example, the battery cells are gathered in modules. The number of cells connected in series defines the voltage level of the powertrain topology of the electric vehicle 100. For "400V", the number of cells connected in series in the battery pack is, for example, 80 to 112 cells, where the maximum voltage Vmax ranges from 336V to 470V.
[0069] Each of the first battery pack BP1 and the second battery pack BP2 includes a first battery pack terminal BP1+, BP2+ and a second battery pack terminal BP1-, BP2-.
[0070] The HV engagement device JD includes a high voltage output terminal for connecting a high voltage load group, wherein the high voltage output terminal includes a first high voltage load terminal HVL+ and a second high voltage load terminal HVL-. The HV load group may include one or more HV loads.
[0071] Furthermore, the HV engagement device JD includes a high voltage input terminal for connecting the electric vehicle power supply equipment, wherein the high voltage input terminal includes a first high voltage charging terminal HVC+ and a second high voltage charging terminal HVC-.
[0072] The first battery terminal BP2+ of the second battery pack BP2 is connected to the first high voltage charging terminal HVC+ via the first contactor C-DC+, and the second battery terminal BP1- of the first battery pack BP1 is connected to the second high voltage charging terminal HVC- via the second contactor C-DC-.
[0073] The first battery terminal BP2+ of the second battery pack BP2 is connected to the first high voltage load terminal HVL+ via the third contactor C-M+, and the second battery terminal BP1- of the first battery pack BP1 is connected to the second high voltage load terminal HVL- via the fourth contactor CM-. The second battery terminal BP2- of the second battery pack BP2 and the first battery terminal BP1+ of the first battery pack BP1 are connected to the first high voltage charging terminal (HVC+) via the fifth contactor C-BP1, and are connected to the second high voltage charging terminal (HVC-) via the sixth contactor C-BP2.
[0074] The connection interconnecting the second battery terminal BP2- of the second battery pack BP2 and the first battery terminal BP1+ of the first battery pack BP1 is without any contactor and relay.
[0075] The HV engagement device JD may include a first overcurrent protection device OCP1 associated with the first battery pack BP1 and a second overcurrent protection device OPC2 associated with the second battery pack BP2 , wherein each of the overcurrent protection devices OCP1 , OCP2 includes a fusible cutout or a high temperature fuse.
[0076] Preferably, the first overcurrent protection device is arranged in the negative supply line of the first battery pack in the HV engagement device, and the second overcurrent protection device is arranged in the positive supply line of the second battery pack in the HV engagement device. The advantage of this position of the overcurrent protection devices OCP1, OCP2 is that they are inside the HV engagement device JD and only three contacts to the battery packs BP1, BP2 are required.
[0077] Alternatively, the first overcurrent protection device OPC1 and the second overcurrent protection device OCP2 associated with the first battery pack BP1 may be arranged in a connection interconnecting the second battery terminal BP2- of the second battery pack BP2 and the first battery terminal BP1+ of the first battery pack BP1.
[0078] Figure 4 The figure shows that when the first battery pack BP1 and the second battery pack BP2 are connected in series, the charging mode is "800V". Figure 3 The energy flow and voltage level of the HV battery system HVBS shown in FIG. In this case, the first to fourth contactors C-DC+, C-DC-, C-M+ and CM- are in a closed state, and the fifth contactor C-BP1 and the sixth contactor C-BP2 are in an open state. Therefore, in this mode, "800V" is supplied to the HV load group.
[0079] Figure 5 Another simplified exemplary circuit diagram of an embodiment of a high voltage (HV) battery system HVBS for an electric vehicle 100, and in particular for a battery electric vehicle (BEV), is shown. Figure 3 and Figure 4 In contrast to the HV battery system HVBS shown in Figure 5 The high voltage output end of the HV engagement device JD shown in the figure includes several connectors connected in parallel for connecting several high voltage loads, so that the high voltage loads are connected in parallel. The HV voltage group includes, for example, a first axle drive M1 and a redundant second axle drive M2, a first DC to DC (DC / DC) converter DC / DC1 and an optional second DC / DC converter DC / DC2, and additional auxiliary high voltage loads, which are, for example, not related to safety. The two input ends of the first DC / DC converter DC / DC1 are connected to the first battery pack BP1 without contactors, and the two input ends of the second DC / DC converter DC / DC2 are connected to the second battery pack BP2 without contactors. Therefore, no contactors are arranged in the connection that interconnects the DC / DC converters DC / DC1, DC / DC2 and the battery packs BP1 and BP2. This solution enables continuous power supply of the 14V on-board power grid even during mode changes without the need for an additional 14V battery.
[0080] exist Figure 5 In the embodiment shown in, in the connection that interconnects the second battery pack terminal BP2- of the second battery pack BP2 and the first battery pack terminal BP1+ of the first battery pack BP1, a first overcurrent protection device OPC1 associated with the first battery pack BP1 and a second overcurrent protection device OCP2 associated with the second battery pack BP2 are arranged, each of which includes a fusible current cutout or a high-temperature fuse.
[0081] also, Figure 5 The energy flow and voltage level in the HV battery system HVBS in the normal "800V" driving mode are shown. In this normal "800V" driving mode, the first battery pack BP1 and the second battery pack BP2 are connected in series. The third contactor C-M+ and the fourth contactor CM- are in the closed state, and the first, second, fifth and sixth contactors C-DC+, C-DC-, C-BP1, C-BP2 are in the open state.
[0082] Figure 6 Shows Figure 5 1 and 2. The energy flow and voltage level of the HV battery system HVBS shown in FIG. 1, wherein the first battery pack BP1 has a defect. Due to the defect, the first overcurrent protection device OPC1 is fused or triggered, and the connection between the first battery pack BP1 and the second battery pack BP2 is interrupted.
[0083] The defect-free second battery pack BP2 is connected to the axle drive and the HV auxiliary load via the second contactor C-DC-, the sixth contactor C-BP2, the fourth contactor CM- and the third contactor C-M+. The 14V vehicle power supply is provided by the second DC / DC converter DC / DC2. The two input terminals of the second DC / DC converter DC / DC2 are connected to the second battery pack BP2 without contactors. This solution enables continuous power supply of the 14V vehicle power supply even during this defect mode without the need for an additional 14V battery.
[0084] Figure 7 Another simplified exemplary circuit diagram of an embodiment of a high voltage battery system HVBS for an electric vehicle 100 , in particular for a battery electric vehicle (BEV), is shown.
[0085] and Figure 5 and Figure 6In contrast to the embodiment shown in , the HV engagement device JD includes at least one further high voltage output terminal having a first terminal HVLn+ and a second terminal HVLn-. The first battery terminal B+ is connected to the first terminal HVLn+ via a seventh contactor C-Ln+, and the second battery terminal B- is connected to the second terminal HVLn- via an eighth contactor C-Ln-. In addition, Figure 7 In the embodiment, the two input terminals of the second axle driver M2 are connected to the first terminal B+ and the second battery terminal B- via an additional contactor. In addition, the positive input terminal of the second DC / DC converter and the negative input terminal of the first DC / DC converter are connected to the terminal B+ and the second battery terminal B- via a contactor.
[0086] Therefore, in this embodiment, the auxiliary high-voltage load, the first axle drive, the second axle drive, and the DC / DC converter group can be disconnected from the battery packs BP1, BP2 independently of each other.
[0087] Figure 8a and Figure 8b shows the alternating charging mode according to Figure 3 The energy flow and voltage level of the HV battery system HVBS. Figure 8a In the process, the first battery pack BP1 is charged. Figure 8b In the example, the second battery pack BP2 is charged. The topology of the HV junction device JD allows separate / alternating charging of the two battery packs BP1, BP2. The HV load is supplied with its nominal voltage of 800V.
[0088] During the alternating charging mode, when the electric vehicle power supply equipment is connected to the first high voltage charging terminal HVC+ and the second high voltage charging terminal HVC- and receives high voltage direct current DC from the electric vehicle power supply equipment, the switching state of each of the first, second, fifth and sixth contactors C-DC+, C-DC-, C-BP1, C-BP2 is controlled by the control unit so that the high voltage DC is alternately routed to the first battery pack BP1 and the second battery pack BP2.
[0089] The control unit may also be referred to as a battery management system BMS. The control unit is configured to send a control signal directly or indirectly to a contactor of the HV engagement device JD for controlling the switching state of the contactor. The battery management system BMS may be part of a high voltage battery system HVBS, or may be assigned to the high voltage battery system HVBS. The control unit may include a controller or a processor configured to execute instructions of a program, which cause the control unit to control the switching state of the contactor of the HV engagement device JD so that the high voltage DC is alternately routed to the first battery pack BP1 and the second battery pack BP2. The control unit may also be configured to control a high temperature fuse.
[0090] The switching frequency for the alternating charge can be adjusted to find the best compromise between a low number of switching events and an acceptable state of charge delta (SoCΔ) for both battery packs.
[0091] Assuming a maximum SoC△ of 3% between battery pack 1 and battery pack 2, a total battery capacity of 75 kWh, and a charging performance of 100 kW @ "400 V"-EVSE, the duration of one charging cycle is about 1.5 min. In this example, 20 switching events are required to charge both battery packs from 20% to 80%.
[0092] During "800V" charging and "400V" charging, all HV components are continuously supplied with their nominal voltage. The HV battery system HVBS (particularly the HV engagement device JD) is able to achieve full performance of all HV auxiliary loads in all charging modes.
[0093] Since the topology of the HV battery system HVBS, in particular the HV joining device JD, does not provide for a parallel connection of battery packs, no measures for cell balancing are required.
[0094] Another advantage of the proposed HV battery system HVBS, in particular of the proposed HV joining device JD, is a higher degree of freedom in the combination of battery packs.
[0095] Therefore, the first battery pack BP1 and the second battery pack BP2 may have different numbers of battery cells and / or include different types of battery cells.
[0096] Parallel charging of battery packs requires that the voltages of both battery packs are the same (or at least very similar). Combinations of battery packs with different numbers of cells or even combinations of battery packs with different types of cells (e.g., lithium nickel cobalt manganese oxide (NMC) and lithium iron phosphate (LiFeP)) are not possible. In contrast, the proposed HV battery system HVBS (particularly the proposed HV junction device JD) in combination with the alternating charging concept enables new expansion concepts that may be more suitable for the OEM's vehicle formation goals.
[0097] Examples of battery capacity expansion using different battery packs of an HV junction device JD are provided below. In order to be able to achieve "400V"-EVSE compatibility, the following prerequisites must be met:
[0098] ·V max_BP1 and V max_BP2 <V max_400V-EVSE (=500V)
[0099] ·V min_BP1 and V min_BP2 >V min_400V-EVSE (=100V)
[0100] Assuming Li-ion-NMC cells, the following BP configurations may be of interest:
[0101] Battery pack 1BP1 (112 cells, 140Ah): 56kWh
[0102] Battery pack 2BP2 (40...112 cells, 140Ah): 20kWh...56kWh
[0103] Total battery capacity (BP1+BP2): 76kWh...112kWh
[0104] Fig. 9 shows the alternating charging mode according to Figure 7 Energy flow and voltage level of the HV battery system HVBS.
[0105] Reference numerals
[0106] 100,200 Electric vehicles
[0107] 101,201 Battery System
[0108] 102,202 Power Distribution Unit
[0109] 103,203 Battery Management System
[0110] 104,106,204,206 Battery Pack
[0111] 108,208 Axle drives
[0112] 110,210 Optional Axle Drives
[0113] 112,212 14V vehicle power supply
[0114] 114,214 Optional 14V vehicle power supply
[0115] 116,216 HV auxiliary load
[0116] 118,218 Overcurrent protection device
[0117] 221 Overcurrent protection device
[0118] 223 Current sensing element
[0119] 220 Battery Switch Matrix
[0120] CT1.1, CT1.2, CT1.3 Battery switch
[0121] B - Second battery terminal
[0122] B+ First battery terminal
[0123] B3 Third battery terminal
[0124] B4 Fourth battery terminal
[0125] B5 Fifth battery terminal
[0126] BP1 First Battery Pack
[0127] BP1 - Second battery terminal of the first battery pack
[0128] BP1+ First battery terminal of the first battery pack
[0129] BP2 Second Battery Pack
[0130] BP2 - Second battery terminal of the second battery pack
[0131] BP2+ First battery terminal of the second battery pack
[0132] C-BP1 Fifth contactor
[0133] C-BP2 Sixth contactor
[0134] C-DC- Second contactor
[0135] C-DC+ First contactor
[0136] C-Ln- Eighth contactor
[0137] C-Ln+ Seventh contactor
[0138] CM- 4th contactor
[0139] C-M+ Third contactor
[0140] DC / DC1 The first DC / DC converter
[0141] DC / DC2 Second DC / DC converter
[0142] HV Auxiliary Auxiliary High Voltage Load
[0143] HVBS High Voltage Battery System
[0144] HVC - Second High Voltage Charging Terminal
[0145] HVC+ First high voltage charging terminal
[0146] HVL - Second High Voltage Load Terminal
[0147] HVL+ First high voltage load terminal
[0148] JD High Voltage Bonding Device
[0149] M1,M2 First axle drive, second axle drive
[0150] OBC Car Charger
[0151] OPC1 First overcurrent protection device
[0152] OPC2 Secondary overcurrent protection device
Claims
1. A bonding device (JD) for a high voltage battery of an electric vehicle (100), wherein - the high voltage battery comprises a first battery pack (BP1) and a second battery pack (BP2) connected in series, - the first battery pack (BP1) and the second battery pack (BP2) each comprise a first battery pack terminal (BP1+, BP2+) and a second battery pack terminal (BP1-, BP2-), - the connection interconnecting the second battery terminal (BP2-) of the second battery (BP2) and the first battery terminal (BP1+) of the first battery (BP1) is free of any contactor and relay, and the engagement device (JD) comprises - a first battery terminal (B+) for connecting the first battery terminal (BP2+) of the second battery pack (BP2) and a second battery terminal (B-) for connecting the second battery terminal (BP1-) of the first battery pack (BP1), - a high voltage output terminal having a first high voltage load terminal (HVL+) and a second high voltage load terminal (HVL-) for connecting a high voltage load group, - a high voltage input terminal having a first high voltage charging terminal (HVC+) and a second high voltage charging terminal (HVC-) for connecting electric vehicle power supply equipment, - a first contactor (C-DC+) and a second contactor (C-DC-), wherein, The first terminal (B+) is connected to the first high voltage charging terminal (HVC+) via the first contactor (C-DC+), and the second battery terminal (B-) is connected to the second high voltage charging terminal (HVC-) via the second contactor (C-DC-), - a third contactor (C-M+) and a fourth contactor (CM-), wherein the first battery terminal (B+) is connected to the first high voltage load terminal (HVL+) via the third contactor (C-M+), and the second battery terminal (B-) is connected to the second high voltage load terminal (HVL-) via the fourth contactor (CM-), - A fifth contactor (C-BP1) and a sixth contactor (C-BP2) and a node (N), wherein the node (N) is connectable to the second battery pack terminal (BP2-) of the second battery pack (BP2) and the first battery pack terminal (BP1+) of the first battery pack (BP1) for providing a voltage level of the connection between the first battery pack (BP1) and the second battery pack (BP2), wherein the node (N) is connected to the first high voltage charging terminal (HVC+) via the fifth contactor (C-BP1) and to the second high voltage charging terminal (HVC-) via the sixth contactor (C-BP2).
2. The joining device (JD) according to claim 1 further includes a third battery terminal (B4) for connecting the second battery pack terminal (BP2-) of the second battery pack (BP2) and a fourth battery terminal (B3) for connecting the first battery pack terminal (BP1+) of the first battery pack (BP1).
3. The joining device (JD) according to claim 1, further comprising an additional battery terminal (B5) for connecting the second battery terminal (BP2-) of the second battery pack (BP2) and the first battery terminal (BP1+) of the first battery pack (BP1).
4. A joining device (JD) according to any one of claims 1 to 3, wherein: The joining device (JD) comprises at least one further high voltage output terminal having a first terminal (HVLn+) and a second terminal (HVLn-), wherein the first battery terminal (B+) is connected to the first terminal (HVLn+) via a seventh contactor (C-Ln+), and the second battery terminal (B-) is connected to the second terminal (HVLn-) via an eighth contactor (C-Ln-).
5. A high voltage HV battery system (HVBS) comprising a high voltage battery for an electric vehicle and a joining device (JD) according to any one of claims 1 to 4, wherein - the high voltage battery comprises a first battery pack (BP1) and a second battery pack (BP2) connected in series, - the first battery pack (BP1) and the second battery pack (BP2) each comprise a first battery pack terminal (BP1+, BP2+) and a second battery pack terminal (BP1-, BP2-), - in a connection interconnecting the second battery pack terminal (BP2-) of the second battery pack (BP2) and the first battery pack terminal (BP1+) of the first battery pack (BP1), a first overcurrent protection device (OCP1) associated with the first battery pack (BP1) and a second overcurrent protection device (OCP2) associated with the second battery pack (BP2) are arranged, the first overcurrent protection device (OCP1) and the second overcurrent protection device (OCP2) each comprising a fusible current cutout or a high-temperature fuse, and - said connection interconnecting said second battery terminal (BP2-) of said second battery (BP2) and said first battery terminal (BP1+) of said first battery (BP1) is free of any contactor and relay.
6. The HV battery system (HVBS) according to claim 5, wherein: The first battery pack (BP1) and the second battery pack (BP2) have different numbers of battery cells.
7. The HV battery system (HVBS) according to claim 5 or 6, wherein: The first battery pack (BP1) and the second battery pack (BP2) include different types of battery cells.
8. A method for operating a high voltage battery system (HVBS) according to any one of claims 5 to 6, wherein: During the charging mode, when the electric vehicle power supply equipment is connected to the first high voltage charging terminal (HVC+) and the second high voltage charging terminal (HVC-) and receives high voltage direct current DC from the electric vehicle power supply equipment, the switching state of each of the first contactor (C-DC+), the second contactor (C-DC-), the fifth contactor (C-BP1) and the sixth contactor (C-BP2) is controlled so that the high voltage DC is alternately routed to the first battery pack (BP1) and the second battery pack (BP2).
9. The method according to claim 8, wherein: A switching frequency for the alternating charging is selected according to the state of charge of the first battery pack (BP1) and / or according to the state of charge of the second battery pack (BP2).
10. A control device for operating the HV battery system (HVBS), wherein: The control device is configured to perform the steps of the method according to claim 8 or 9.
11. A computer program comprising instructions which, when executed by a controller or a processor of a control unit, cause the control unit to perform the steps of the method according to claim 8 or 9.
12. A computer readable medium having stored thereon a computer program according to claim 11.