Control and management of retrofit and vehicle loads

Abstract

The invention provides control and management of retrofit and vehicle loads. The controller reduces a setpoint of the first DC / DC converter to be equal to a setpoint of the second DC / DC converter when a state of charge of a supplemental battery providing power to the electrical bus via the first DC / DC converter is greater than a predefined threshold and in response to an amount of current value associated with a load on the electrical bus exceeding a predefined value, the second DC / DC converter transfers power between the electrical bus and the traction battery such that the load is powered by the supplemental battery and the traction battery.

Description

Technical Field

[0001] The present disclosure relates to automotive power systems. Background Art

[0002] A motor vehicle may include an energy storage device, such as a battery. This energy may be used in the electrical and electronic components of the vehicle and outside the vehicle. For example, aftermarket snow plow equipment may be powered by energy from a battery. Such a connection to a battery may be facilitated by a so-called upfitter module. Summary of the invention

[0003] An electrical system for a vehicle includes: an electrical bus; a first DC / DC converter that transfers power between the electrical bus and a traction battery; a second DC / DC converter that transfers power between a supplemental battery and the electrical bus; and one or more controllers that, in response to a state of charge of the supplemental battery falling below a predefined threshold, reduce a set point of the second DC / DC converter to be less than a set point of the first DC / DC converter such that a load on the electrical bus is powered by the traction battery rather than the supplemental battery.

[0004] A method for a vehicle includes, when a state of charge of a supplemental battery configured to provide power to an electrical bus via a first DC / DC converter is greater than a predefined threshold and in response to a current magnitude associated with a load on the electrical bus exceeding a predefined value, reducing a set point of the first DC / DC converter to be equal to a set point of a second DC / DC converter configured to transfer power between the electrical bus and a traction battery such that the load is powered by the supplemental battery and the traction battery.

[0005] A vehicle includes: an electrical bus; an alternator that provides power to the electrical bus; a battery; a DC / DC converter that transfers power between the battery and the electrical bus; and one or more controllers that, in response to a state of charge of the battery falling below a predefined threshold, reduce a set point of the DC / DC converter to less than a set point of the alternator so that a load on the electrical bus is powered by the alternator rather than the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of parts of a battery electric vehicle.

[0007] Figure 2 is a schematic diagram of a portion of an internal combustion engine vehicle. DETAILED DESCRIPTION

[0008] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be enlarged or minimized to show details of particular components. Therefore, the specific structural details and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art.

[0009] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired.

[0010] Motor vehicles typically include a power supply to facilitate the operation of various electrical and electronic components. Several power supply architectures are commonly used in automotive applications, including centralized, decentralized, and hybrid power supply architectures.

[0011] A centralized power architecture may include a single power supply unit that provides power to all electrical and electronic components in a vehicle. This architecture may be simple and easy to install. However, in some cases, it may not be suitable for vehicles with high power requirements or those with different voltage levels for different components.

[0012] A decentralized power architecture may include multiple power supply units located near the components they power. This architecture may be more flexible than a centralized power architecture because it allows different voltage levels to be provided to different components. It may also improve efficiency by reducing power losses that occur when power transmission distances are relatively long. However, a decentralized power architecture may be more complex as the number of connections between the power supply units and the corresponding components potentially increases.

[0013] A hybrid power architecture can be a combination of centralized and decentralized power architectures: a central power supply unit provides power to some electrical and electronic components, while other components are powered by decentralized power supply units. In some applications, this architecture can provide a balance between flexibility and efficiency.

[0014] The use of a modifier module may affect the power system of a motor vehicle. In some examples, a modifier module is a modular component that can be added to a vehicle to provide additional modifier functions (such as lighting, power distribution, or power management). For example, a modifier module that provides lighting and power distribution can be installed in a vehicle, allowing the vehicle to be used as a work vehicle, such as a service truck or construction vehicle. In addition, a modifier module can be designed to meet specific requirements, such as providing power to a specific modifier component or group of modifier components (modifier load).

[0015] In selecting a retrofit module, several factors may be considered, including the power requirements of the component or group of components that the retrofit module will power, the required voltage level, and the environmental conditions in which the retrofit module will be used.

[0016] Some retrofitter modules have taken the form of switches mounted in the overhead compartment and relays in an additional engine compartment switch box. In some arrangements, wires are fed to the engine compartment switch box but are not connected to the relays. The screen can be used to support touch actuation of the field effect transistors controlling the load.

[0017] A DC / DC converter can convert the voltage level of DC power from one level to another. Some vehicles (e.g., electric or hybrid vehicles) may feature a battery with an integrated DC / DC converter. That is, the DC / DC converter is physically built into the battery pack or tightly integrated with it. This integration can help optimize the use of available space and reduce the need for additional components.

[0018] In this context, the primary function of a DC / DC converter may be to convert the high voltage DC power (typically several hundred volts) generated by a battery into lower voltage DC power suitable for charging another battery or powering various vehicle systems and accessories (e.g., mod loads).

[0019] To support rescue and disaster relief, large batteries (e.g., 12V deep cycle or high voltage batteries) can be added to the cargo compartment of a vehicle (e.g., a truck). These batteries can have a DC / DC converter integrated with them. Vehicles equipped with so-called cargo compartment batteries can provide power for long periods of time without visiting a charging station. Therefore, battery swapping may be required. It may be desirable to provide continuous power even when the battery is being swapped or when its state of charge is low.

[0020] In the context of a battery electric vehicle, power flow from the traction battery and the cargo battery may be controlled via manipulation of the associated DC / DC converter set points. During situations where the vehicle is providing power in a rescue situation, the voltage set point of the DC / DC converter integrated with the cargo battery may be set slightly higher than the voltage set point of the main DC / DC converter associated with the traction battery. For example, if the set point of the main DC / DC converter is 13V, the set point of the integrated DC / DC converter may be 13.1V. The set point of any additional DC / DC converters in the vehicle may be set slightly lower than the set point of the main DC / DC converter (e.g., 12.9V). Thus, the modifier loads served by the vehicle will be powered by the cargo battery rather than the traction battery until the load is sufficient to reduce the system voltage from 13.1V to 13V, at which point power from the traction battery and cargo battery will serve the modifier loads.

[0021] This multi-battery multi-DC / DC converter arrangement can also allow power from one of the batteries to be used to charge another of the batteries. Continuing with the above example, the integrated DC / DC converter can be operated to transfer power from the cargo compartment battery to an electrical bus shared with the main DC / DC converter. At the same time, the main DC / DC converter can be operated to transfer power from the electrical bus to the traction battery to charge the traction battery. Other scenarios are also possible.

[0022] When the state of charge of the cargo compartment battery drops below a certain threshold (e.g., 15%), the integrated DC / DC converter set point can be reduced to below the set point of the main DC / DC converter. Continuing with the example above, the integrated DC / DC converter set point can be reduced to 12.9V, while the main DC / DC converter set point can remain at 13.0V. Thus, the modifier loads served by the vehicle will be powered by the traction battery rather than the cargo compartment battery. During this transition, the cargo compartment battery can be swapped or charged. Once completed, the set point of the integrated DC / DC converter can be returned to 13.1V because the state of charge will be greater than 15%.

[0023] Load sharing between the batteries may be performed under certain conditions, such as load, temperature, and state of charge conditions. For example, if the magnitude of the current associated with the retrofit load exceeds a certain threshold (e.g., 250A) while the state of charge of the cargo bed battery is greater than a certain value (e.g., 40%), the set point of the integrated DC / DC converter may be set equal to the set point of the main DC / DC converter so that the power from the traction battery and the cargo bed battery satisfies the retrofit load.

[0024] Once the set points are equal, other conditions may affect the mix of power supplied by the traction battery and the cargo battery. If, for example, the set point is set equal to 100A of the modifier load, then additional load currents in excess of 100A may be met 80% by the traction battery and 20% by the cargo battery (e.g., at 200A, the cargo battery would supply 120A and the traction battery would supply 80A). For example, additional load currents in excess of 300A may be met solely by the traction battery (e.g., at 500A, the cargo battery would supply its maximum current of 140A and the traction battery would supply 360A).

[0025] The relative temperatures of the DC / DC converter and / or the battery can be used to distribute power between them. If, for example, the temperature of the integrated DC / DC converter and / or the cargo compartment battery falls outside of a certain desired range, the traction battery can meet the demand for additional load current to maintain or reduce the temperature increase of the integrated DC / DC converter and / or the cargo compartment battery.

[0026] Similarly, the demand for additional load current may be met by the battery with the higher state of charge. If the traction battery has an 80% state of charge and the cargo battery has a 50% state of charge, the demand for additional load current may be met by the traction battery rather than the cargo battery to better conserve the charge available from the cargo battery.

[0027] In the context of a vehicle including an internal combustion engine, power flow from the alternator and the cargo compartment battery can be controlled by manipulating the alternator and integrated DC / DC converter set points in a manner similar to that described above. That is, in some cases, the integrated DC / DC converter set point can be set higher than the alternator set point so that the load is satisfied first using power from the cargo compartment battery. When the state of charge of the cargo compartment battery drops below a certain threshold, the integrated DC / DC converter set point can be set lower than the set point of the alternator. When the demand for load current exceeds a certain value, the set points can be set to be equal. And the mix of power supplied by the alternator and the cargo compartment battery can depend on the magnitude of the load current, the temperature of the integrated DC / DC converter and / or the cargo compartment battery, and the state of charge of the cargo compartment battery.

[0028] refer to Figure 1, vehicle 10 includes a cargo box 12 (e.g., a truck bed), a traction battery 14, a DC / DC converter 16 (e.g., a main DC / DC converter), a supplemental battery 18, a DC / DC converter 20 (e.g., an integrated DC / DC converter), one or more controllers 22, a DC / DC converter 24 (e.g., a protected DC / DC converter), and an electrical bus 26. Other known vehicle and electrical components (e.g., power electronics components, power distribution components, retrofit modules, switches, etc.) have been omitted for clarity and ease of understanding.

[0029] The DC / DC converter 16 is electrically connected between the traction battery 14 and an electrical bus 26. The DC / DC converter 20 is electrically connected between the supplemental battery 18 and the electrical bus 26. The supplemental battery 18 and the DC / DC converter 20 are located within the cargo bed 12. The DC / DC converter 24 is electrically connected to the electrical bus 26.

[0030] The revamp load 28 is also electrically connected to the electrical bus 26 via standard revamp technology (e.g., a revamp module). The revamp module may also facilitate electrical connection between the DC / DC converter 20 and the electrical bus 26. That is, the DC / DC converter 20 may access the electrical bus 26 via the revamp module.

[0031] One or more controllers 22 and Figure 1 The controller 22 may communicate with and / or exert control over the associated components. Standard sensors (such as temperature sensors, current sensors, etc.) may facilitate such communication and control. For example, each of the components may have a standard temperature sensor and current sensor associated therewith and in communication with the one or more controllers 22. Thus, the one or more controllers 22 may implement the various DC / DC set point control strategies described above. For example, the one or more controllers 22 may reduce the set point of the DC / DC converter 20 to less than the set point of the DC / DC converter 16 in response to the state of charge of the supplemental battery 18 falling below a certain predefined threshold, so that the refurbisher load 28 is powered by the traction battery 14 instead of the supplemental battery 18. The one or more controllers 22 may increase the set point to greater than the set point of the DC / DC converter 16 in response to the state of charge exceeding the predefined threshold, so that the refurbisher load 28 is powered by the traction battery 18 instead of the traction battery 14. If the state of charge is greater than the predefined threshold, the one or more controllers 22 may set the set points of the DC / DC converters 16, 20 to be equal, so that the refurbisher load 28 is powered by the traction battery 14 and the supplemental battery 18. Also, the mix of power from the traction battery 14 and supplemental battery 18 may be varied as described above depending on the magnitude of the load current, temperature, state of charge, etc.

[0032] refer to Figure 2, the vehicle 30 includes a cargo box 32 (e.g., a truck bed), an engine 34, an alternator 36, a supplemental battery 38, a DC / DC converter 40 (e.g., an integrated DC / DC converter), one or more controllers 42, and an electrical bus 46. Figure 1 , other known vehicle and electrical components (eg, power electronics components, power distribution components, retrofit modules, switches, etc.) have been omitted.

[0033] The alternator 36 is connected between the engine 34 and an electrical bus 44. The DC / DC converter 40 is electrically connected between the supplemental battery 38 and the electrical bus 44. The supplemental battery 38 and the DC / DC converter 40 are located within the cargo bed 32.

[0034] The retrofit load 46 is also electrically connected to the electrical bus 44 via standard retrofit techniques. Figure 1 The retrofit module may also facilitate electrical connection between the DC / DC converter 40 and the electrical bus 44 .

[0035] One or more controllers 42 and Figure 2 Communicate with and / or exert control over associated components. Figure 1 , standard sensors (such as temperature sensors, current sensors, etc.) can facilitate such communication and control. Thus, one or more controllers 42 can implement the various DC / DC set point control strategies described above.

[0036] The algorithm, method or process disclosed herein can be delivered to or implemented by a computer, controller or processing device, which can include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithm, method or process can be stored in various forms as data and instructions that can be executed by a computer or controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disk, a random access memory device or other magnetic and optical media. The algorithm, method or process can also be implemented as a software executable object. Alternatively, the algorithm, method or process can be embodied in whole or in part using a combination of suitable hardware components (such as an application-specific integrated circuit, a field programmable gate array, a state machine or other hardware components or devices) or firmware, hardware and software components.

[0037] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are descriptive rather than limiting, and it should be understood that various changes can be made without departing from the spirit and scope of these disclosed materials. For example, the terms "controller" and "multiple controllers" can be used interchangeably herein because the functionality of a controller can be distributed across several controllers / modules, which can all communicate via standard technologies.

[0038] As previously mentioned, the features of the various embodiments may be combined to form additional embodiments of the present invention that may not be explicitly described or shown. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be appreciated by those of ordinary skill in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, and the like. Therefore, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of the present disclosure and may be desirable for a particular application.

[0039] According to the present invention, there is provided an electrical system for a vehicle, the electrical system having: an electrical bus; a first DC / DC converter configured to transfer power between the electrical bus and a traction battery; a second DC / DC converter configured to transfer power between a supplemental battery and the electrical bus; and one or more controllers programmed to: in response to a state of charge of the supplemental battery falling below a predefined threshold, reduce a set point of the second DC / DC converter to be less than a set point of the first DC / DC converter, so that a load on the electrical bus is powered by the traction battery instead of the supplemental battery.

[0040] According to one embodiment, the one or more controllers are further programmed to: in response to the state of charge exceeding a predefined threshold, increase the set point to be greater than the set point of the first DC / DC converter so that the load on the electrical bus is powered by the supplemental battery rather than the traction battery.

[0041] According to one embodiment, the one or more controllers are further programmed to, when the state of charge is greater than a predefined threshold and in response to a current magnitude associated with the load exceeding a predefined value, reduce the set point to be equal to a set point of the first DC / DC converter such that the load is powered by the traction battery rather than the supplemental battery.

[0042] According to one embodiment, the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery according to the magnitude.

[0043] According to one embodiment, the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery as a function of temperature.

[0044] According to one embodiment, the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery based on the state of charge of the supplemental battery and the state of charge of the traction battery.

[0045] According to one embodiment, the one or more controllers are further programmed to operate the first DC / DC converter and the second DC / DC converter to charge the traction battery with power from the supplemental battery.

[0046] According to one embodiment, the invention is also characterized by a third DC / DC converter having a set point that is lower than the set point of the first DC / DC converter.

[0047] According to one embodiment, the supplemental battery is disposed within the cargo compartment of the vehicle.

[0048] According to the present invention, a method for a vehicle includes: when a state of charge of a supplemental battery configured to provide power to an electrical bus via a first DC / DC converter is greater than a predefined threshold and in response to a current magnitude associated with a load on the electrical bus exceeding a predefined value, reducing a set point of the first DC / DC converter to be equal to a set point of a second DC / DC converter configured to transfer power between the electrical bus and a traction battery such that the load is powered by the supplemental battery and the traction battery.

[0049] In one aspect of the invention, the method includes varying the relative amounts of power provided by the supplemental battery and the traction battery according to the magnitude.

[0050] In one aspect of the invention, the method includes varying the relative amounts of power provided by the supplemental battery and the traction battery as a function of temperature.

[0051] In one aspect of the invention, the method includes varying the relative amounts of power provided by the supplemental battery and the traction battery based on the state of charge of the supplemental battery and the state of charge of the traction battery.

[0052] In one aspect of the invention, the method includes, in response to the state of charge falling below a predefined threshold, reducing the set point to less than the set point of the second DC / DC converter such that the load is powered by the traction battery rather than the supplemental battery.

[0053] According to the present invention, a vehicle is provided, the vehicle having: an electrical bus; an AC generator, the AC generator being configured to provide power to the electrical bus; a battery; a DC / DC converter, the DC / DC converter being configured to transfer power between the battery and the electrical bus; and one or more controllers, the one or more controllers being programmed to reduce a set point of the DC / DC converter to be less than a set point of the AC generator in response to a state of charge of the battery dropping below a predefined threshold, so that a load on the electrical bus is powered by the AC generator rather than the battery.

[0054] According to one embodiment, the one or more controllers are further programmed to, in response to the state of charge exceeding a predefined threshold, increase the set point to be greater than the set point of the alternator such that loads on the electrical bus are powered by the battery rather than the traction battery.

[0055] According to one embodiment, the one or more controllers are further programmed to, in response to a current magnitude associated with the load exceeding a predefined value, reduce the set point to be equal to the set point of the alternator such that the load is powered by the alternator rather than the battery.

[0056] According to one embodiment, the one or more controllers are also programmed to vary the relative amounts of power provided by the alternator and the battery according to the magnitude.

[0057] According to one embodiment, the one or more controllers are also programmed to vary the relative amounts of power provided by the alternator and the battery as a function of temperature.

[0058] According to one embodiment, the one or more controllers are also programmed to vary the relative amounts of power provided by the alternator and the battery depending on the state of charge.

Claims

1. An electric power system for a vehicle, the electric power system comprising: Electrical bus; a first DC / DC converter configured to transfer power between the electrical bus and a traction battery; a second DC / DC converter configured to transfer power between a supplemental battery and the electrical bus; as well as and one or more controllers programmed to, in response to the state of charge of the supplemental battery falling below a predefined threshold, reduce a set point of the second DC / DC converter to be less than a set point of the first DC / DC converter such that a load on the electrical bus is powered by the traction battery rather than the supplemental battery.

2. The power system of claim 1 , wherein the one or more controllers are further programmed to: in response to the state of charge exceeding the predefined threshold, increase the set point to be greater than the set point of the first DC / DC converter so that a load on the electrical bus is powered by the supplemental battery rather than the traction battery.

3. The power system of claim 1 , wherein the one or more controllers are further programmed to, when the state of charge is greater than the predefined threshold and in response to a current magnitude associated with the load, reduce the set point to be equal to a set point of the first DC / DC converter such that the load is powered by the traction battery rather than by the supplemental battery.

4. The power system of claim 3, wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery based on the magnitude.

5. The power system of claim 3, wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery as a function of temperature.

6. The power system of claim 3, wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the traction battery and the supplemental battery based on the state of charge of the supplemental battery and the state of charge of the traction battery.

7. The power system of claim 1, wherein the one or more controllers are further programmed to operate the first DC / DC converter and the second DC / DC converter to charge the traction battery using power from the supplemental battery. 8 . The power system of claim 1 , further comprising a third DC / DC converter, a set point of the third DC / DC converter being smaller than a set point of the first DC / DC converter.

9. The power system of claim 1, wherein the supplemental battery is disposed within a cargo compartment of the vehicle.

10. A vehicle comprising: Electrical bus; an alternator configured to provide power to the electrical bus; Battery; a DC / DC converter configured to transfer power between the battery and the electrical bus; as well as One or more controllers programmed to, in response to the state of charge of the battery dropping below a predefined threshold, reduce a set point of the DC / DC converter to less than a set point of the alternator such that a load on the electrical bus is powered by the alternator rather than by the battery.

11. The vehicle of claim 10, wherein the one or more controllers are further programmed to: in response to the state of charge exceeding the predefined threshold, increase the set point to a set point greater than the set point of the alternator such that a load on the electrical bus is powered by the battery rather than by the alternator.

12. The vehicle of claim 10 wherein the one or more controllers are further programmed to, in response to a current magnitude associated with the load exceeding a predefined value, reduce the set point to be equal to a set point of the alternator such that the load is powered by the alternator rather than by the battery.

13. The vehicle of claim 12 wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the alternator and the battery based on the magnitude.

14. The vehicle of claim 12 wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the alternator and the battery as a function of temperature.

15. The vehicle of claim 12 wherein the one or more controllers are further programmed to vary the relative amounts of power provided by the alternator and the battery based on the state of charge.

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