DESC:CROSS REFERENCE TO RELATED APPLICATION
[001] This application is based on and derives the benefit of Indian Provisional Application 201741044052, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
[002] Embodiments disclosed herein relate to vehicle energy systems and more particularly to an architecture for 48V/12V energy systems in vehicles.
BACKGROUND
[003] In addition to traditional propulsion systems, i.e. the engine, a 48V system used in automobiles comprises of a belt driven or crank shaft mounted electric motor as the second propulsion system. This electric motor obtains power from a 48V energy source to provide torque assist to the engine and to support the High Voltage (HV) vehicle loads.
[004] In the conventional 48V energy system architecture, a 48V lithium-ion battery is used in conjuncture with a traditional 12V lead-acid battery. In this scenario, the 48V energy source powers the belt-starter generator (BSG) to support engine cranking and provide torque assist during acceleration. It also provides power to the HV loads of the vehicle. During the recuperation event, the BSG acts in a generator mode to charge the 48V energy source by capturing the braking energy via the DC/DC converter. The 12V lead acid battery can be used to power the low-voltage vehicle board net loads and assist in engine cranking using the starter motor in case of a failure of the BSG.
[005] Current solutions comprise a single primary energy source connected to various modules connected in series and/or parallel where switching between various high and low voltage configurations are possible by means of switching elements.
OBJECTS
[006] The principal object of embodiments herein is to disclose architecture for a 48V/12V energy system in a vehicle, wherein the system can either be used as a standalone 48V lithium-ion system with the conventional 12V lead acid system or as a dual 12V lead-acid/lithium-ion system.
[007] Another object of embodiments herein is to modularize the adaptive 12V Li-ion side of the 48V system so that battery management, life, recycling and replacement can be optimized.
[008] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[009] Embodiments herein are illustrated in the accompanying drawings, through out which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0010] FIGs. 1a and 1b depict an example schematic of the 48V/12V adaptive architecture, according to embodiments as disclosed herein; and
[0011] FIGs. 2a, 2b, 2c, 2d, 2e and 2f depict example configurations of the architecture, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0012] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0013] The embodiments herein achieve an architecture for a 48V/12V energy system in a vehicle, wherein the system can either be used as a standalone 48V lithium-ion system with the conventional 12V lead acid system or as a dual 12V lead-acid/lithium-ion system. Referring now to the drawings, and more particularly to FIGs. 1a through 2f, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0014] Embodiments herein disclose a 48V lithium-ion system that can be adapted to a 12V lithium-ion system by means of voltage deactivation to support the conventional 12V lead acid system. The 48V/12V energy architecture disclosed herein can also perform the functionalities of a conventional 48V architecture.
[0015] FIGs. 1a and 1b depict an example schematic of the 48V/12V adaptive architecture. The adaptive 48V/12V energy system architecture 100 disclosed herein comprises a 48V Li-ion battery 101, wherein Li-ion battery 101 comprises a plurality of adaptive modules (as depicted in FIGs. 1a and 1b). The 48V battery 101 can contain either a single or multiple adaptive modules (101a and 101b (as depicted in FIG. 1a) or 101c, 101d, and 101e (as depicted in FIG. 1b)) depending on the desired functionality and switching architecture.
[0016] In an embodiment herein, the 48V Li-ion battery 101 comprises of two modules of 33.3V 101a and 14.8V 101b respectively which are connected in series via a relay 1 102a (as depicted in FIG. 1a). The 14.8V module 101a has an adaptive functionality such that it can be voltage deactivated and isolated from the 48V architecture 100 and connected in parallel with a conventional 12V lead acid battery 104 to obtain a dual 12V lithium-ion/lead-acid architecture using a relay 2 102b and a relay 3 102c.
[0017] In an embodiment herein, the 48V Li-ion battery 101 comprises of three modules 101c, 101d, and 101e (as depicted in FIG. 1b), each of 12V. The 12V lithium-ion module 101c, 101d, 101e supports or boosts the performance of the 12V lead-acid battery 104, whenever required. In an embodiment herein, the 12V lead-acid battery 104 can be downsized (wherein it is smaller and lighter than a standard 12V lead-acid battery used in vehicles), which in turn can help in weight reduction and obtaining better fuel economy as compared to a conventional 48V system.
[0018] In an embodiment herein, a 12V lithium-ion module 101c, 101d, 101e can top/charge the 12V lead-acid battery 104, thereby maintaining it at a desired state of charge and improving its cycle life performance. The 12V lithium-ion module 101c, 101d, 101e can charge the 12V lead-acid battery 104 during recuperation event(s). Also, the 48V battery 101 can be used to charge the 12V lead-acid battery 104 based on hybrid function definition.
[0019] Given that overall battery life improves on controlled cycling, embodiments herein enhance the cycle life of the energy storage system(s) 101, 104. The functionality of multiple module switching can be achieved and enhanced by the use of improvised chemistries.
[0020] In the event of failure of the 12V battery 104, sudden interruption or loss of power to a Low Voltage (LV) vehicle Boardnet loads might occur. To ensure there is no loss in system functionality, the 12V module 101c, 101d, 101e can act as a power net backup for the LV Boardnet loads.
[0021] In an embodiment herein, a 12V BSG can be used instead of a starter motor. The 12V BSG will derive power from the 12V battery 104 under normal operational conditions or can be powered by one of the modules (101a, 101b, 101c, 101d, 101e) in the event of failure of the standalone 12V energy system.
[0022] Embodiments herein can perform adaptive charging. The 48V battery 101 can be charged during the recuperation and alternator cycle by harnessing braking energy of the vehicle. In the event of failure of the 48V BSG 105, the 12V lead-acid battery 104 can be charged using the 14.8V battery 101b. The 14.8V battery 101b can passively charge the other adaptive modules. This ensures uniform charge balance across all the modules (101a, 101b, 101c, 101d, 101e) of the overall 48V system.
[0023] In an embodiment herein, the architecture 100 can comprise of a DC/DC converter 103, which can convert 48V DC to 12V DC.
[0024] The following configurations of the architecture 100 are possible.
Configuration 1 (as depicted in FIG. 2a): Conventional 48V lithium-ion/ 12V lead-acid architecture
(Relay 1 102a: CLOSED; Relay 2 102b: OPEN; Relay 3 102c: CLOSED): The 48V architecture used in 2W, 3W and 4W comprises of a secondary propulsion system (i.e. a motor/generator) in addition to the primary propulsion system (i.e. an engine). The energy storage architecture in this case comprises of a 48V energy source to power the 48V motor/generator and support the HV vehicle loads. The 12V lead-acid battery 104 powers the LV Boardnet loads and aids in engine cranking via the starter motor in the event of BSG failure.
Configuration 2 (as depicted in FIG. 2b): Dual 12V lithium-ion/lead-acid architecture (Relay 1 102a: OPEN; Relay 2 102b: CLOSED; Relay 3 102c: OPEN): The 14.8V module 101b of the 48V battery 101 has an adaptive functionality such that it can either be used as part of the standalone 48V system (Configuration 1) or in parallel with the 12V lead-acid battery 104. The 12V lithium-ion battery connected in parallel can support or boost the 12V lead-acid battery 104, whenever required. This dual 12V lithium-ion/lead-acid architecture enables use of a lower capacity lead-acid battery 104 thereby reducing the system weight, which in turn translates into better fuel efficiency. It is envisioned that the architecture depicted in FIG. 1 can enhance the cycle life of the 12V lead-acid battery 104 by charging the lead-acid battery 104 and maintaining the lead-acid battery 104 at an optimum state-of-charge.
[0025] When the battery 101 is operating in 48V mode, the relays are configured as follows: relay 1 102a - Closed, relay 2 102b - Closed, relay 3 102c - Open, relay 4 102d - Closed, relay 5 102e - Open, and relay 6 102f - Open (as depicted in FIG. 2c).
[0026] When the 12V module 1 101c is operating/being used, the relays are configured as follows: relay 1 102a - Open, relay 4 102d - Open, relay 5 102e - Closed, and relay 6 102f - Open (as depicted in FIG. 2d).
[0027] When the 12V module 2 101d is operating/being used, the relays are configured as follows: relay 1 102a - Open, relay 2 102b - Open, relay 3 102c - Closed, relay 4 102d - Open, relay 5 102e - Open, and relay 6 102f - Closed (as depicted in FIG. 2e).
[0028] When the 12V module 3 101e is operating/being used, the relays are configured as follows: relay 1 102a - Open, relay 2 102b - Open, relay 3 102c - Open, relay 4 102d - Open, relay 5 102e - Open, and relay 6 102f - Closed (as depicted in FIG. 2f).
[0029] In case, both the energy storage systems (i.e. the 48V battery 101 and 12V battery 104) are of matching chemistries, the 48V battery 101 can be swapped or used interchangeably with the 12V battery 104 to achieve enhanced functionalities in terms of performance and cycle life as well as greater operational flexibility.
[0030] Embodiments herein can lead to downsizing the lead acid battery, which also helps in minimizing the lead footprint. Embodiments herein can lead to an improvement in the fuel economy and enhancing the life of the lead acid battery by cycling it and maintaining at the desired SOC (State of Charge) level at all times.
[0031] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:We claim:
1. A 48V/12V energy system architecture (100) for a vehicle, the system comprising:
a 48V lithium-ion battery (101); and
a 12V lead-acid battery (104);
wherein the 48V lithium-ion battery (101) comprises at least one of
a first module of 33.3V (101a) and an adaptable second module of 14.8V (101b); and
a plurality of 12V modules (101c, 101d and 101e).
2. The 48V/12V energy system architecture (100), as depicted in claim 1, wherein the second module of 14.8V (101b) is connected in parallel with a 12V lead acid battery (104) using a second relay (102b) and a third relay (102c).
3. The 48V/12V energy system architecture (100), as depicted in claim 2, wherein the 48V lithium-ion battery (101) is configured for charging the 12V lead acid battery (104).
4. The 48V/12V energy system architecture (100), as depicted in claim 1, wherein the 48V lithium-ion battery (101) is configured for serving as a power net backup for at least one Low Voltage (LV) Boardnet load present in the vehicle.
5. The 48V/12V energy system architecture (100), as depicted in claim 1, wherein the architecture (100) comprises a 12V belt-starter generator (BSG), which is configured to be used a starter motor for the vehicle and can be powered by at least one of the 48V battery (101) and the 12V lead-acid battery (104).
6. The 48V/12V energy system architecture (100), as depicted in claim 1, wherein the 48V battery (101) is charged using braking energy of the vehicle.