Multi-voltage vehicle operation

Abstract

The vehicle includes two or more battery packs configured to supply power to the motor. The controller is configured to dynamically activate an operating mode during operation. The operating mode is one of a plurality of possible operating modes including a first operating mode defining a series connection between two or more battery packs and a second operating mode defining a parallel connection between two or more battery packs. Connection between the battery packs is controlled by a first plurality of switches. The plurality of low voltage loads are connected to a subset of the battery packs such that power outputs of the subset of the battery packs provide full power to the plurality of low voltage loads. In both the first mode of operation and the second mode of operation, the plurality of low voltage loads are connected to only the subset of the battery packs.

Description

Technical Field

[0001] The present disclosure relates to multi-voltage vehicle operation. Background Art

[0002] An electric vehicle or hybrid vehicle (e.g., a car, truck, construction equipment, farm equipment, automated factory equipment) may include two or more battery packs that provide power for the propulsion of the vehicle. Typically, these components are connected in parallel for vehicle operation. That is, two or more battery packs are connected in parallel to power a power inverter module (PIM) for each motor. For example, a vehicle may include one or more front motors (front motors) and rear motors (rear motors). In some scenarios, a vehicle may benefit from more power. Therefore, it is desirable to provide multi-voltage vehicle operation. Summary of the invention

[0003] In an exemplary embodiment, a system in a vehicle includes: two or more battery packs configured to power one or more motors of the vehicle to move the vehicle, a controller configured to dynamically activate an operating mode of a multi-level voltage system of the vehicle during vehicle operation, the operating mode being one of a plurality of possible operating modes, wherein the plurality of possible operating modes include a first operating mode defining a series connection between the two or more battery packs and a second operating mode defining a parallel connection between the two or more battery packs, and wherein the connection between the two or more battery packs is controlled by a first plurality of switches, a plurality of low-voltage loads connected to a subset of the battery packs in the two or more battery packs such that power outputs of the subset of the batteries in the two or more battery packs provide power to the plurality of low-voltage loads, and wherein in both the first operating mode and the second operating mode, the plurality of low-voltage loads are connected only to the subset of the battery packs.

[0004] In any of the above examples, high voltage terminals of a subset of low voltage loads are connected to high voltage terminals of a subset of batteries independently of the pattern of the first plurality of switches, and low voltage terminals of the subset of batteries are connected to low voltage terminals of the multi-level voltage system.

[0005] In any of the above examples, the connection between the high voltage terminals of the subset of low voltage loads and the high voltage terminals of the subset of batteries is a direct non-switched connection.

[0006] In any of the above examples, low voltage terminals of a subset of low voltage loads are connected to low voltage terminals of a subset of batteries independently of the state of the first plurality of switches, and high voltage terminals of the subset of batteries are connected to high voltage terminals of the multi-level voltage system.

[0007] In any of the above examples, the connection between the low voltage terminals of the subset of low voltage loads and the low voltage terminals of the subset of batteries is a direct non-switched connection.

[0008] Any of the above examples also includes a configurable low voltage load connection, which includes a first connection line connecting the high voltage terminal of a subset of the low voltage loads to the high voltage terminal of a first subset of batteries in two or more battery packs, a second connection line connecting the high voltage terminal of the subset of the low voltage loads to the high voltage terminal of a second subset of batteries in two or more battery packs, a third connection line connecting the low voltage terminal of the low voltage loads to the low voltage terminal of the first subset of batteries in the two or more battery packs, and a fourth connection line connecting the low voltage terminal of the low voltage loads to the low voltage terminal of the second subset of batteries in the two or more battery packs.

[0009] In any of the above examples, the first connection line includes a first configurable low voltage load switch, the second connection line includes a second configurable low voltage load switch, the third connection line includes a third configurable low voltage load switch, and the fourth connection line includes a fourth low voltage load connection switch.

[0010] In any of the above examples, when the first and third configurable low-voltage load switches are closed and the second and fourth configurable low-voltage load switches are open, the subset of low-voltage loads is connected to a first subset of batteries in the two or more battery packs.

[0011] In any of the above examples, when the second and fourth configurable low-voltage load switches are closed and the first and third configurable low-voltage load switches are open, the subset of low-voltage loads is connected to a second subset of batteries in the two or more battery packs.

[0012] Any of the above examples also includes a controller configured to control the states of first, second, third and fourth configurable low voltage load switches, and the controller is also configured to change the states of the first, second, third and fourth configurable low voltage load switches to change which subset of batteries in two or more battery packs is connected to the low voltage load.

[0013] In any of the above examples, the controller is configured to change states of first, second, third, and fourth configurable low voltage load switches in response to charge levels of a first subset of batteries in two or more battery packs and a second subset of batteries in two or more battery packs.

[0014] In any of the above examples, each battery in the two or more battery packs is contained within exactly one of the first subset of batteries and the second subset of batteries in the two or more battery packs.

[0015] In another example embodiment, a method of assembling a system in a vehicle includes arranging two or more battery packs to power one or more motors of the vehicle to move the vehicle, configuring a controller to dynamically activate an operating mode of a multi-level voltage system of the vehicle during vehicle operation, the operating mode being one of a plurality of possible operating modes, wherein the plurality of possible operating modes include a first operating mode defining a series connection between the two or more battery packs and a second operating mode defining a parallel connection between the two or more battery packs, and arranging a set of low voltage loads to receive power from a subset of the two or more battery packs regardless of which operating mode is activated.

[0016] In any of the above examples, arranging a collection of low-voltage loads to receive power from a subset of two or more battery packs independently of which operating mode is activated includes connecting high voltage terminals of the subset of low-voltage loads to high voltage terminals of a subset of batteries independent of a mode of a first plurality of switches, and connecting low voltage terminals of the subset of batteries to low voltage terminals of a multi-level voltage system.

[0017] In any of the above examples, the connection between the high voltage terminals of the subset of low voltage loads and the high voltage terminals of the subset of batteries is a direct non-switched connection.

[0018] In any of the above examples, the two or more battery packs include a plurality of mutually exclusive subsets, and wherein the controller is configured to change which mutually exclusive subset is connected to the low voltage load using a configurable connection and in response to at least one detected condition.

[0019] In any of the above examples, the configurable connection includes: a configurable low voltage load connection, which includes a first connection line connecting the high voltage terminal of a subset of the low voltage loads to the high voltage terminal of a first subset of batteries in two or more battery packs, a second connection line connecting the high voltage terminal of the subset of the low voltage loads to the high voltage terminal of a second subset of batteries in two or more battery packs, a third connection line connecting the low voltage terminal of the low voltage load to the low voltage terminal of the first subset of batteries in the two or more battery packs, and a fourth connection line connecting the low voltage terminal of the low voltage load to the low voltage terminal of the second subset of batteries in the two or more battery packs.

[0020] In any of the above examples, the at least one detected condition is one of an unbalanced charging condition in the two or more battery packs and initiation of a charging operation of the two or more battery packs.

[0021] In any of the above examples, the detected state is an unbalanced state of charge, and the configurable connections are altered so that the low voltage load is connected to the highest charged subset of the battery subsets.

[0022] In any of the above examples, the detected state is the initiation of a charging operation, and the configurable connections are changed so that the low voltage loads are connected to the first subset of batteries when the second subset of batteries is charged, and are connected to the second subset of batteries when the first subset of batteries is charged.

[0023] The above features and advantages and other features and advantages of the present disclosure are apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages and details appear, by way of example only, from the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 is a block diagram of a vehicle having a multi-voltage propulsion system according to one or more embodiments;

[0026] Figure 2 According to another embodiment, a low voltage connection of a subset power supply to a load is included Figure 1 A block diagram of a vehicle;

[0027] Figure 3 According to yet another embodiment, a low voltage connection to a subset of power loads is included. Figure 1 a block diagram of a vehicle; and

[0028] Figure 4 According to yet another embodiment Figure 1 A block diagram of a vehicle including a switched low voltage connection to a subset of power loads. DETAILED DESCRIPTION

[0029] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0030] Embodiments of the systems and methods detailed herein relate to multi-voltage vehicle operation. An electric vehicle or hybrid vehicle may include two or more battery packs. A battery pack refers to a plurality of batteries or battery cells managed by a battery management system (BMS). A battery pack and an associated BMS may be collectively referred to as a smart battery pack. Battery packs are typically connected in parallel during vehicle operation. Thus, for example, two 400 volt (V) battery packs may be arranged in parallel to supply 400 V to each PIM of each motor (electric machine) of the vehicle and to different loads (e.g., integrated power electronics, air conditioning systems).

[0031] Exemplary embodiments relate to changing the connection to two or more battery packs to allow some loads to receive a high voltage from a battery pack in series with one or more PIMs and one or more loads, and at the same time allow other loads to receive a low voltage from one of the battery packs, regardless of whether the battery packs are currently connected in parallel or in series. According to one or more embodiments, the battery packs can be dynamically connected in series to supply a higher voltage to the PIMs and one or more loads. According to another embodiment, the battery packs can be statically connected in series to supply a higher voltage to the PIMs and one or more loads. This may be desirable for a higher power operating mode, while the parallel connection of the battery packs may be desirable for a higher efficiency operating mode. Certain loads will always require a lower voltage for operation, and efficiency can be improved by allowing a lower voltage load to be constantly connected to a single battery pack within two or more battery packs. For the purpose of explanation, two battery packs are used to describe a multi-voltage output. However, any number of battery packs can be used, where the static connection shown is pulled to a single battery pack. For example, three 400V battery packs can be connected in series to supply 1200V to a first group of loads, where a single 400V battery pack is connected to a load that requires a lower voltage supply.

[0032] According to an exemplary embodiment, Figure 1 1 is a block diagram of a vehicle 100 having a multi-voltage propulsion system 110. An exemplary vehicle 100 is a car 101. Two exemplary battery packs 120-A and 120-B (generally referred to as 120) power a front motor 130-F, a left rear motor 130-LR, and a right rear motor 130-RR (generally referred to as motor 130). The battery packs 120 also power a load 150. The battery packs 120 can be charged by a direct current fast charger (DCFC) 160 or an onboard charging module (OBCM) 180 powered by an alternating current (AC) grid 170. Each of the battery packs 120-A and 120-B is shown as having a corresponding BMS 125-A and 125-B (generally referred to as 125). In an alternative example, the two battery packs 120-A, 120-B are controlled by a single BMS 125.

[0033] The BMS 125 of each battery pack 120 or a single shared BMS 125 can indicate the state of charge, temperature, voltage, current, and other parameters used to make decisions, such as, for example, whether charging is required. In embodiments that include this capability, these parameters can also indicate when a change in low voltage load supply from the first battery pack 120-A to the second battery pack 120-B (or vice versa) is warranted. In addition to components not detailed herein, the propulsion system 110 includes the battery pack 120 and the motor 130 (in Figure 1 ).

[0034] The vehicle 100 is shown with a controller 115. The controller 115 can implement dynamic changes between series connection and parallel connection of the battery packs 120 as detailed herein. In one practical example, the controller 115 is incorporated into the functionality of the BMS 125 and is a software module. In an alternative example, the controller 115 functionality can be implemented in a dedicated controller, implemented as a software system distributed around multiple vehicle controllers, or any similar system. The various switches SA1, SA2, SA3, SB1, SB2, SB3, SA, SB are controlled to facilitate dynamic changes between series connection and parallel connection of the battery packs 120, and in Figure 1-4 All are shown in the open position. The switches can be controlled by the controller 115 to close, as shown by the arrows. Implementations of dynamic changes between series and parallel connections of the battery packs 120 based on changes in the operating mode of the vehicle 100 (e.g., between high power and high efficiency) have been previously disclosed and are not discussed in detail herein.

[0035] The controller 115 may include processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) executing one or more software or firmware programs and memory, combinational logic circuits, and / or other suitable components that provide the described functionality. The memory of the controller 115 may include a non-transitory computer-readable medium storing instructions that, when processed by one or more processors of the controller 115, implement dynamic changes and control switches for providing a direct low voltage connection to the low voltage load 150 while providing a high voltage connection to the motor 130 and the onboard charging module 180.

[0036] When the battery packs 120-A and 120-B are connected in series, switches SB2, SA, SB, and SA1 are closed, thereby generating a high voltage output to the motor 130 and the loads 150, 180 by connecting the high voltage terminal of the first battery pack 120-A to the high voltage terminal P2 of the multi-level voltage system 110, connecting the low voltage terminal of the first battery pack 120-A to the high voltage terminal of the second battery pack 120-B, and connecting the low voltage terminal of the second battery pack 120-B to the low voltage terminal P1 of the multi-level voltage system 110. In some existing systems, any load 150 that cannot accept the higher voltage generated by the series connection of the battery packs 120 can be supplied via a DC-DC converter, which reduces the voltage from the battery pack 120 to a voltage accepted by the load 150. Figure 2-4 In the example of FIG. 1 , the connection to a single battery pack allows loads 150 requiring lower voltage to be connected directly to the single battery pack 120 and the DC-DC converter can be omitted. Omitting the DC-DC converter reduces vehicle weight and complexity.

[0037] When the connection between the battery packs 120 is dynamically changed, or when one or more battery packs 120 are first activated individually, in parallel, or in series (i.e., in a particular power mode), or when a given power mode is deactivated, current may surge into the motor 130 and the load 150 due to a current imbalance between the battery packs 120 and the motor 130 or the load 150. To limit the inrush current, the pre-charge circuit contactors 140-A and 140-B and the pre-charge resistor 145 are first used in a specific order.

[0038] exist Figure 1 In an alternative example, one or more additional loads may require the same voltage as the motor 130 and may be connected in parallel with the motor 130, similar to the lower voltage 150. Also included in the multi-voltage propulsion system 110 is a set of high voltage positive battery terminal fuses (pyrolysis switches) 210 and a plurality of voltage / current sensors 220. The pyrolysis switches 210 are high voltage positive battery terminal fuses that destructively and irreversibly disconnect electrical connections to avoid short circuits, thereby preventing overcurrent and thermal runaway conditions. The voltage / current sensors 220 are conventional voltage and current sensors that provide feedback to any controller, including the OBCM 180 and / or DCFC 160, for monitoring and adjusting the power characteristics of the multi-voltage propulsion system 110. Communications from the voltage / current sensors 220 may be via any conventional communications protocol or connection.

[0039] Continue to refer Figure 1 , Figure 2 and Figure 3An embodiment of a multi-voltage propulsion system 110 is shown that is configured to provide lower voltage power directly to lower voltage loads 150 while providing higher voltage power to motors 130 and any other loads that may require high voltage power.

[0040] Specific reference Figure 2 In the embodiment of the present invention, the high voltage terminal 202 of each of the lower voltage loads 150 is directly connected to the positive terminal 201 of the second battery pack 120-B via a direct connection 155, and the negative / low voltage terminal 204 of the lower voltage loads 150 and the OBCM 180 is connected to the negative / low voltage terminal 203 of the second battery pack 120-B through the switch SB2 and the thermal decomposition switch 210. The direct connection 155 allows each of the loads 150 and the OBCM 180 to receive power only from the second battery pack 120-B, regardless of whether the battery packs 120 are connected in series or in parallel.

[0041] Specific reference Figure 3 In the embodiment of the present invention, the high voltage terminal 202 of the lower voltage load 150 and the OBCM 180 are directly connected to the connection point P2 of the high voltage terminal of the multi-level voltage system 110 via a direct connection 165. The low / 0 voltage terminal 204 of each load 150 and OBCM 180 is connected to the negative terminal 161 of the first battery group 120-A through a thermal switch 210. The direct connection 165 allows each of the load 150 and the OBCM 180 to receive power only from the first battery group 120-A, regardless of whether the battery groups 120 are connected in series or in parallel.

[0042] This article expects Figure 2 and Figure 3 The embodiments may be combined so that a subset of the low voltage loads 150 are connected via Figure 3 The connections shown are connected to the first battery pack 120-A, and a subset of the low voltage loads 150 are connected via Figure 2 The connection shown is connected to the second battery pack 120-B. In such an example, Figure 2 and Figure 3 Both embodiments are simultaneously incorporated into a single multi-voltage propulsion system.

[0043] In some examples, by providing a switched connection from the high voltage terminal 202 of the load 150 and a switched connection from the low voltage terminal 204 of the load 150, the Figure 2 and Figure 3 The direct connection of a single battery pack 120 can be combined with a flexible connection. The flexible connection is called a configurable low voltage load connection. Figure 4An embodiment of a flexible connection is shown, wherein the high voltage terminal 202 of each load 150 is connected to the positive terminal 201, 203 of each battery pack 120 via corresponding switches 232-A, 232-B. Switches 232-A and 232-B can be paired into a single switch with two modes. For example, switches 232-A and 232-B can be electromechanical double throw switches or paired semiconductor solid state relays. Similarly, the low / 0 voltage terminal 204 of each load 150 is connected to the negative terminal 205, 207 of the corresponding battery pack 120-A, 120-B via corresponding switches 234-A, 234-B. Like switches 232-A, 232-B, switches 234-A, 234-B can be paired into a single switch with two modes. For example, switches 234-A and 234-B can be electromechanical double throw switches or paired semiconductor solid state relays. Each of the switches 232 , 234 is controlled via a switch controller, such as the OBCM 180 , the DCFC 160 , or any similar controller.

[0044] During operation, the low voltage load 150 can be connected to the first battery pack 120-A by closing the corresponding switches 232-A, 234-A and keeping the switches 232-B, 234-B corresponding to the second battery pack 120-B open. Conversely, the low voltage load 150 can be connected to the second battery pack 120-B by closing the corresponding switches 232-B, 234-B and keeping the switches 232-A, 234-A open. In series mode, the low voltage load 150 needs to switch between 120-A or 120-B to maintain the balance of voltage / SOC in the battery pack. When in parallel mode, the low voltage load 150 is connected in parallel with the two battery packs, and the battery packs self-balance each other.

[0045] When operating in a low power, high efficiency mode where the battery packs 120 are placed in parallel for the motor 130 , the battery pack 120 -A, 120 -B to which the low voltage load 150 is connected may become more discharged than the other battery pack 120 -A, 120B. Figure 4 The flexible mode shown in the embodiment of allows the controller to actively balance the state of charge of each battery pack 120-A, 120B by connecting the load 150 to the battery pack 120-A, 120-B with the higher state of charge.

[0046] In addition, during some operation of the vehicle (e.g., during braking, during driving at cruising speed, etc.), charging power can be obtained from one or more other sources within the vehicle 110. During this mode, the DCFC 160 can charge the first battery pack 120-A, while the low voltage load 150 and the motor 130 are connected to the second battery pack 120-B. Once the first battery pack 120-A is sufficiently charged, the connection is switched, the second battery pack 120-B is charged, and the motor 130 and the load 150 are connected to the first battery pack 120-A. Once sufficient charge is achieved, the battery packs 120-A, 120-B can be placed in series and standard operation is resumed.

[0047] The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced item. Unless the context clearly indicates otherwise, the term "or" means "and / or". References to "aspects" throughout the specification mean that a particular element (e.g., a feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in the various aspects.

[0048] When an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

[0049] Unless otherwise indicated herein, all test standards are the most current standards in effect as of the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0050] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0051] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from its scope. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the disclosure without departing from the basic scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A system in a vehicle, comprising: two or more battery packs configured to power one or more motors of the vehicle to move the vehicle; a controller configured to dynamically activate an operating mode of the multi-level voltage system of the vehicle during vehicle operation, the operating mode being one of a plurality of possible operating modes, wherein the plurality of possible operating modes includes a first operating mode defining a series connection between the two or more battery packs and a second operating mode defining a parallel connection between the two or more battery packs, and wherein the connection between the two or more battery packs is controlled by a first plurality of switches; a plurality of low voltage loads connected to a subset of the battery packs of the two or more battery packs such that power outputs of the subset of the battery packs of the two or more battery packs provide power to the plurality of low voltage loads; as well as Wherein, in both the first operating mode and the second operating mode, the plurality of low voltage loads are connected only to the subset of the battery pack.

2. A system according to claim 1, wherein the high voltage terminals of the subset of low voltage loads are connected to the high voltage terminals of the subset of batteries independently of the mode of the first plurality of switches, and the low voltage terminals of the subset of batteries are connected to the low voltage terminals of the multi-level voltage system, and optionally, wherein the connection between the high voltage terminals of the subset of low voltage loads and the high voltage terminals of the subset of batteries is a direct non-switched connection.

3. The system according to claim 1, wherein: The low voltage terminals of the subset of low voltage loads are connected to the low voltage terminals of the subset of batteries independently of the state of the first plurality of switches, and the high voltage terminals of the subset of batteries are connected to the high voltage terminals of the multi-level voltage system, and optionally, the connection between the low voltage terminals of the subset of low voltage loads and the low voltage terminals of the subset of batteries is a direct non-switched connection.

4. The system according to claim 1 further includes a configurable low voltage load connection, the configurable low voltage load connection including a first connection line connecting the high voltage terminal of a subset of the low voltage loads to the high voltage terminal of a first subset of batteries in the two or more battery groups, a second connection line connecting the high voltage terminal of the subset of the low voltage loads to the high voltage terminal of a second subset of batteries in the two or more battery groups, a third connection line connecting the low voltage terminal of the low voltage load to the low voltage terminal of the first subset of batteries in the two or more battery groups, and a fourth connection line connecting the low voltage terminal of the low voltage load to the low voltage terminal of the second subset of batteries in the two or more battery groups.

5. The system of claim 4, wherein the first connection line comprises a first configurable low voltage load switch, the second connection line comprises a second configurable low voltage load switch, the third connection line comprises a third configurable low voltage load switch, and the fourth connection line comprises a fourth low voltage load connection switch.

6. The system according to claim 5, wherein: When the first and third configurable low voltage load switches are closed and the second and fourth configurable low voltage load switches are open, the subset of low voltage loads are connected to a first subset of the batteries in the two or more battery packs.

7. The system according to claim 6, wherein: When the second configurable low voltage load switch and the fourth configurable low voltage load switch are closed and the first configurable low voltage load switch and the third configurable low voltage load switch are open, the subset of low voltage loads are connected to a second subset of the batteries in the two or more battery packs.

8. The system of claim 5, further comprising a controller configured to control states of the first, second, third, and fourth configurable low voltage load switches, the controller further configured to change states of the first, second, third, and fourth configurable low voltage load switches to change which subset of batteries in the two or more battery packs are connected to the low voltage load, and optionally, wherein the controller is configured to change the first, second, third, and fourth configurable low voltage load switches in response to charge levels of the first subset of batteries in the two or more battery packs and the second subset of batteries in the two or more battery packs.

9. A method of assembling a system in a vehicle, the method comprising: two or more battery packs are arranged to power one or more motors of the vehicle to move the vehicle; configuring a controller to dynamically activate an operating mode of the multi-level voltage system of the vehicle during vehicle operation, the operating mode being one of a plurality of possible operating modes, wherein the plurality of possible operating modes includes a first operating mode defining a series connection between the two or more battery packs and a second operating mode defining a parallel connection between the two or more battery packs; as well as A group of low voltage loads is arranged to receive power from a subset of the two or more battery groups independent of which operating mode is activated.

10. The method according to claim 9, wherein: The system is a system according to any one of claims 1 to 8.

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