Claims:WE CLAIM:
1. An electrical system (100) for a three wheeled vehicle, the electrical system (100) comprising:
a high voltage subsystem (102);
a low voltage subsystem (104); and
a Controller Area Network (CAN) bus (106) interfaced between components of the high voltage subsystem (102) and the low voltage subsystem (104), the CAN bus (106) configured to communicate status signals between components of the high voltage subsystem (102) and the low voltage subsystem (104).

2. The electrical system (100) as claimed in claim 1, wherein the high voltage subsystem (102) comprises a plurality of batteries (102A), an On-board charger (102B), a motor (102C), an Off-board charger (102F), and a DC charger (102G).

3. The electrical system (100) as claimed in claim 1, wherein the low voltage subsystem (104) comprises a DC-DC converter (104A), a Vehicle Control Unit (VCU) (104B), a Motor Control Unit (MCU) (104C), a plurality of electrical loads (104D), at least one auxiliary battery (104E) supplying power to the electrical loads (104D), a telematics unit (104F), an instrument cluster (104G) and a diagnostic tool (104H).
4. The electrical system (100) as claimed in claim 3 comprising a ground connection (108) at a chassis under a dashboard, a ground connection (110) to the chassis near a motor bus bar (102D), a ground connection (112) to the chassis while mounting the DC-DC converter (104A), a ground connection (114) to the chassis near a powertrain of the vehicle, a ground connection (116) to the chassis at a bracket of the auxiliary battery (104E), and a ground connection (118) to the chassis near the batteries (102A) located at a front portion of the three wheeled vehicle.

5. The electrical system (100) as claimed in claim 1 comprising a Battery Management System (BMS) (102E) being configured to monitor status of the plurality of batteries (102A), wherein the status of the plurality of batteries is communicated on the CAN bus (106).

6. The electrical system (100) as claimed in claim 1, wherein fault status signals indicating faults in the high voltage subsystem (102) and the low voltage subsystem (104) are available on the CAN bus (106) and the faults are displayed on the instrument cluster (104G).

7. The electrical system (100) as claimed in claim 1, wherein each of the high voltage subsystem (102) and the low voltage subsystem (104) comprise a plurality of power lines and wherein each of the power lines is isolated from the CAN bus (106) using bus bars and the ground connections (108, 110, 112, 114, 116, 118) for preventing an interface between them, thereby avoiding corruption of data.

8. The electrical system (100) as claimed in claim 3, wherein the telematics unit (104F) is in communication with the CAN bus (106), the telematics unit (104F) being configured to display status of the three wheeled vehicle in real-time based on status signals available on the CAN bus (106).

9. The electrical system (100) as claimed in claim 2, wherein the plurality of batteries (102A) are charged by any one of the AC On-board charger (102B), the AC Off-board charger (102F) and the DC charger (102G).

10. The electrical system (100) as claimed in claim 2, wherein the MCU (104C) and a motor / motor drive unit (104I) have a secondary communication line (120) between them, the secondary communication line (120) interfaces with the CAN bus (106) of the three wheeled vehicle.

11. The electrical system (100) as claimed in claim 1, wherein the CAN bus (106) is a multi-master type.

12. The electrical system (100) as claimed in claim 3, wherein the DC-DC converter (104A) is a non-isolated type.

13. The electrical system (100) as claimed in claim 1, wherein the low voltage subsystem (104) is supplied with power from the high voltage subsystem (102) by conversion of the high voltage via the DC-DC converter (104A).

14. A three wheeled vehicle comprising:
a chassis for supporting one or more vehicular parts;
a dashboard mounted on the chassis;
an electrical system (100) for driving the three wheeled vehicle, the electrical system (100) comprising:
a high voltage subsystem (102) comprising a plurality of batteries (102A) and at least one motor (102C);
a low voltage subsystem (104) electrically connected to the high voltage subsystem (102), the low voltage subsystem (104) comprising a plurality of control units (104C, 104B), an instrument cluster (104G), a plurality of electrical loads (104D) and a DC-DC converter (104A); and
a Controller Area Network (CAN) bus (106) interfacing components of the high voltage subsystem (102) and the low voltage subsystem (104), the CAN bus (106) configured to communicate status signals between the components of the high voltage subsystem (102) and the low voltage subsystem (104).

15. The three wheeled vehicle as claimed in claim 14, wherein the high voltage subsystem (102) comprises an On-board charger (102B), the motor (102C), an Off-board charger (102F), and a DC charger (102G).

16. The three wheeled vehicle as claimed in claim 14, wherein the low voltage subsystem (104) comprises at least one auxiliary battery (104E) supplying power to the electrical loads (104D), a telematics unit (104F) and a diagnostic tool (104H).

17. The three wheeled vehicle as claimed in claim 16 comprising a ground connection (108) at a chassis under a dashboard, a ground connection (110) to the chassis near a motor bus bar (102D), a ground connection (112) to the chassis while mounting the DC-DC converter (104A), a ground connection (114) to the chassis near a powertrain of the vehicle, a ground connection (116) to the chassis at a bracket of the Auxiliary battery (104E), and a ground connection (118) to the chassis near the batteries (102A) located at a front portion of the three wheeled vehicle.

18. The three wheeled vehicle as claimed in claim 14 comprising a Battery Management System (BMS) (102E) being configured to monitor status of the plurality of batteries (102A), wherein the status of the plurality of batteries is communicated on the CAN bus (106).

19. The three wheeled vehicle as claimed in claim 14, wherein fault status signals indicating faults in the high voltage subsystem (102) and the low voltage subsystem (104) are available on the CAN bus (106) and the faults are displayed on the instrument cluster (104G).

20. The three wheeled vehicle as claimed in claim 14, wherein each of the high voltage subsystem (102) and the low voltage subsystem (104) comprise a plurality of power lines and wherein each of the power lines is isolated from the CAN bus (106) using bus bars and the ground connections (108, 110, 112, 114, 116, 118) for preventing an interface between them, thereby avoiding corruption of data.

21. The three wheeled vehicle as claimed in claim 16, wherein the telematics unit (104F) is in communication with the CAN bus (106), the telematics unit (104F) being configured to display status of the three wheeled vehicle in real-time based on status signals available on the CAN bus (106).

22. The three wheeled vehicle as claimed in claim 14, wherein the plurality of batteries (102A) are charged by any one of the AC On-board charger (102B), the AC Off-board charger (102F) and the DC charger (102G).

23. The three wheeled vehicle as claimed in claim 14, wherein the MCU (104C) and a motor / motor drive unit (104I) have a secondary communication line (120) between them, the secondary communication line (120) interfaces with the CAN bus (106) of the three wheeled vehicle.

24. The three wheeled vehicle as claimed in claim 14, wherein the CAN bus (106) is a multi-master type.

25. The three wheeled vehicle as claimed in claim 14, wherein the DC-DC converter (104A) is a non-isolated type.

26. The three wheeled vehicle as claimed in claim 14, wherein the low voltage subsystem (104) is supplied with power from the high voltage subsystem (102) by conversion of the high voltage via the DC-DC converter (104A).

Dated this 28th day of December 2021

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471 , Description:FIELD OF THE INVENTION
[001] The present invention generally relates to an electrical system for a vehicle.

BACKGROUND OF THE INVENTION
[002] Existing vehicles have different electrical systems with different voltage levels, such as, 48V system and 12V system. The 48V system components are batteries, a motor control unit and a motor. The 12V system involves an auxiliary battery and electrical loads connected to the battery via a DC-DC converter.
[003] In such vehicles, there is one centralised controller for the motor, a speedometer, an instrument cluster, telematics, etc., which was part of the 48V system. The disadvantage associated with such an electrical system is that, hacking of the one single controller can expose whole of the electrical system of the vehicle. Also, the existing DC-DC converter in such electrical systems is an isolated type converter and all the control units in communication were all having individual ground connections in the vehicle. However, the isolated converter suffered from problems of core losses as transformers were being used. Also, the different individual grounding connections on the vehicle were to be monitored. This is also an expensive affair and maintainability of the electrical system, and the vehicle is an issue.
[004] In a conventional three wheeled electrical vehicles driven by multiple batteries and a motor, multiple CAN buses are present, where one CAN bus is for communication of Battery Management System (BMS) of the batteries with a vehicle control unit and another CAN bus is for interconnecting the telematics unit, the speedometer, and the instrument cluster with the vehicle control unit. Such multiple CAN buses for safety critical electrical system of the vehicle itself were leading to use of a gateway controller between these buses, increasing complexity and cost of implementation of such architecture. Though debugging of problem in each CAN bus may be performed, it is still an expensive solution. Further, infrastructure for such multiple CAN buses needs to be avoided as the CAN bus protection circuits also have to be implemented.
[005] Further, master slave architecture between the BMS of the individual battery is used in conventional electrical vehicles. Due to the master slave architecture, there is a delay in communication of status of the batteries to the BMS. Also, diagnosis of the errors with the electrical system and CAN bus in the existing electrical vehicles is not indicated to the rider of the vehicle and neither there is any analysis provided to service personnel.
[006] In addition to the above, in the existing electrical vehicles, the inverters that supply power to the motor are part of the motor control unit and not of the motor. Therefore, the inverters require individual protection circuits, and the motor control unit becomes clumsier and bulky.
[007] Thus, there is a need in the art for an electrical system for a vehicle like three wheeled vehicle which could address at least the aforementioned problems and limitations.

SUMMARY OF THE INVENTION
[008] In one aspect, the present invention is directed to an electrical system for a three wheeled vehicle. The electrical system includes a high voltage subsystem, a low voltage subsystem, and a Controller Area Network (CAN) bus interfaced between components of the high voltage subsystem and the low voltage subsystem. The CAN bus is configured to communicate status signals between components of the high voltage subsystem and the low voltage subsystem.
[009] In an embodiment, the high voltage subsystem includes a plurality of batteries, an On-board charger, a motor, an Off-board charger, and a DC charger.
[010] In an embodiment, the low voltage subsystem includes a DC-DC converter, a Vehicle Control Unit (VCU), a Motor Control Unit (MCU), a plurality of electrical loads, at least one auxiliary battery supplying power to the electrical loads, a telematics unit, an instrument cluster and a diagnostic tool.
[011] In an embodiment, the electrical system includes a ground connection at a chassis under a dashboard, a ground connection to the chassis near a motor bus bar, a ground connection to the chassis while mounting the DC-DC converter, a ground connection to the chassis near a powertrain of the vehicle, a ground connection to the chassis at a bracket of the auxiliary battery, and a ground connection to the chassis near the batteries located at a front portion of the three wheeled vehicle.
[012] In an embodiment, the electrical system includes a Battery Management System (BMS) is configured to monitor status of the plurality of batteries. The status of the plurality of batteries is communicated on the CAN bus.
[013] In an embodiment, fault status signals indicating faults in the high voltage subsystem and the low voltage subsystem are available on the CAN bus and the faults are displayed on the instrument cluster.
[014] In an embodiment, each of the high voltage subsystem and the low voltage subsystem include a plurality of power lines and wherein each of the power lines is isolated from the CAN bus using bus bars and the ground connections preventing an interface between them, thereby avoiding corruption of data.
[015] In an embodiment, the telematics unit is in communication with the CAN bus. The telematics unit being configured to display status of the three wheeled vehicle in real-time based on status signals available on the CAN bus.
[016] In an embodiment, the plurality of batteries are charged by any one of the AC On-board charger, the AC Off-board charger and the DC charger.
[017] In an embodiment, the MCU and a motor / motor drive unit have a secondary communication line between them. The secondary communication line interfaces with the CAN bus of the three wheeled vehicle.
[018] In an embodiment, the CAN bus is a multi-master type.
[019] In an embodiment, the DC-DC converter is a non-isolated type.
[020] In an embodiment, the low voltage subsystem is supplied with power from the high voltage subsystem by conversion of the high voltage via the DC-DC converter.
[021] In another aspect, the present invention is directed to a three wheeled vehicle includes a chassis for supporting one or more vehicular parts, a dashboard mounted on the chassis, an electrical system for driving the three wheeled vehicle. The electrical system includes a high voltage subsystem having a plurality of batteries and at least one motor. The electrical system further includes a low voltage subsystem electrically connected to the high voltage subsystem. The low voltage subsystem includes a plurality of control units, an instrument cluster, a plurality of electrical loads and a DC-DC converter. The electrical system further includes a Controller Area Network (CAN) bus interfacing components of the high voltage subsystem and the low voltage subsystem. The CAN bus is configured to communicate status signals between the components of the high voltage subsystem and the low voltage subsystem.

BRIEF DESCRIPTION OF THE DRAWINGS
[022] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a schematic block diagram of an electrical system of a vehicle, in accordance with an exemplary embodiment of the present invention.
Figure 2 illustrates a schematic block diagram of components of a high voltage subsystem and a low voltage subsystem of the electrical system shown in Figure 1, in accordance with an embodiment of the present invention.
Figure 3 illustrates a schematic diagram of grounding of the components of the high voltage subsystem and the low voltage subsystem, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[023] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. In the ensuing exemplary embodiments, the vehicle is a three-wheeled vehicle. However, it is contemplated that the disclosure in the present invention may be applied to any automobile like a four-wheeled vehicle capable of accommodating the present subject matter without defeating the scope of the present invention.
[024] The present invention relates to an electrical system for a vehicle, for example, a three wheeled vehicle.
[025] Figure 1 illustrates a schematic block diagram of an electrical system 100 for a three wheeled vehicle, in accordance with an exemplary embodiment of the present invention. In an exemplary embodiment, the three wheeled vehicle is an electric vehicle. The vehicle typically includes, but not limited to, a chassis (not shown) for supporting and/or mounting one or more vehicular parts like a dashboard (not shown).
[026] As illustrated in Figure 1, an electrical system 100 of the vehicle includes a high voltage subsystem 102, a low voltage subsystem 104, and a Controller Area Network (CAN) bus 106 interfaced between components of the high voltage subsystem 102 and the low voltage subsystem 104. The CAN bus 106 is configured to communicate status signals between components of the high voltage subsystem 102 and the low voltage subsystem 104. In one non-exemplary embodiment of the present invention, the CAN bus 106 is a multi-master type and not a master slave type. The status signals indicate the health of the different components of the high voltage subsystem 102 and the low voltage subsystem 104.
[027] Figure 2 illustrates a schematic block diagram of components of the high voltage subsystem 102 and the low voltage subsystem 104 of the electrical system 100 shown in Figure 1, in accordance with an embodiment of the present invention. In an exemplary embodiment, the high voltage subsystem 102 is of 48V and include components such as, but not limited to, a plurality of batteries 102A, an AC on-board charger 102B, a motor 102C (shown in Figure 3), an AC off-board charger 102F, and a DC charger 102G. The components of the high voltage subsystem 102 and the low voltage subsystem 104 are connected via bus bars or cables. The motor 102C receives power from the batteries 102A over a motor bus bar 102D (shown in Figure 3).
[028] In an exemplary embodiment, the low voltage subsystem 104 is of 12V and include components such as, a DC-DC converter 104A. The DC-DC converter 104A is a non-isolated type. The DC-DC converter 104A is used to step-down a power supply from 48V to 12V so that the components in the low voltage subsystem 102 are not subjected to an overvoltage.
[029] The low voltage subsystem 104 further includes a Vehicle Control Unit (VCU) 104B. The VCU 104B is an electronic component communicating between a Battery Management System (BMS) 102E, a charge monitoring unit (not shown), the motor 102C, and electrical loads 104D (shown in Figure 3). The VCU 104B performs functions related to monitoring, sensing, charging and all over communication.
[030] The low voltage subsystem 104 further includes a Motor Control Unit (MCU) 104C. The MCU 104C is an electronic component communicating between the BMS 102E and the motor 102C. The MCU 104C handles essential motor control functions such as torque request, throttle validation, mode selection etc. In an embodiment, the MCU 104C and a motor / motor drive unit 104I have a secondary communication line 120 between them. The secondary communication line 120 interfaces with the CAN bus 106 of the three wheeled vehicle.
[031] The low voltage subsystem 104 further includes at least one auxiliary battery 104E (shown in Figure 3) for supplying power to the electrical loads 104D of the vehicle. In other words, the auxiliary battery 104E is a 12V battery which is used to power the components of the low voltage subsystem 104 during an ignition mode before the batteries 102A wake-up. In an embodiment, the electrical loads 104D in the vehicle may include, but not limited to, lamps, horns and other accessory loads of the vehicle.
[032] The low voltage subsystem 104 further includes a telematics unit 104F. The telematics unit 104F is configured for vehicle tracking and battery parameter monitoring. The telematics unit 104F is powered by the auxiliary battery 104E when the vehicle is turned OFF. In an embodiment, the telematics unit 104F is in communication with the CAN bus 106 of the three wheeled vehicle. The telematics unit 104F is configured to track the status of the three wheeled vehicle in a real-time and remotely display the status on the vehicle on a user device of the user of the vehicle.
[033] The low voltage subsystem 104 further includes an instrument cluster 104G. The instrument cluster 104G typical includes a display for rider’s essential information such as speedometer, odometer, driving and regeneration mode details. The low voltage subsystem 104 further includes a diagnostic tool 104H. Fault status signals indicating faults in the high voltage subsystem 102 and the low voltage subsystem 104 are available on the CAN bus 106 and the faults are displayed on the instrument cluster 104G. With the help of the diagnostic tool 104H, debugging of the faults can be performed.
[034] Referring further to Figure 2, it illustrates the electrical system 100 having the Battery Management System (BMS) 102E. In an embodiment, the BMS 102E is in communication with the plurality of batteries 102A. In an exemplary embodiment, the BMS 102E is configured to communicate the status of the plurality of batteries 102A on the same CAN bus 106. In an embodiment, the plurality of batteries 102A is charged by any one of the charging means, including, but not limited to, the AC on-board charger 102B, the AC off-board charger 102F and the DC charger 102G.
[035] Figure 3 illustrates a schematic diagram of grounding of the components of the high voltage subsystem 102 and the low voltage subsystem 104 of the electrical system 100, in accordance with an embodiment of the present invention.
[036] As illustrated in Figure 3, the electrical system 100 includes ground connection all along the vehicle at a chassis of the vehicle. The electrical system 100 includes a ground connection 108 at the chassis under the dashboard. The ground connection 108 is made for the electrical loads 104 provided at a front portion of the vehicle.
[037] Further, the electrical system 100 includes a ground connection 110 to the chassis near the motor bus bar 102D. The electrical system 100 further includes a ground connection 112 to the chassis while mounting the DC-DC converter 104A.
[038] The electrical system 100 further includes a ground connection 114 to the chassis near a powertrain of the vehicle. In an embodiment, a gearbox mounting may be provided between the motor 102C and the powertrain of the vehicle.
[039] The electrical system 100 further includes a ground connection 116 to the chassis at a bracket of the auxiliary battery 104E. Further, a ground connection 118 to the chassis near the batteries 102A located at a front portion of the three wheeled vehicle is provided.
[040] In an embodiment, the electrical system 100 includes an isolation of power lines using the bus bars and the ground connections 108, 110, 112, 114, 116, 118 from status signals over the CAN bus 106 for preventing an interface between them, thereby avoiding corruption of data.
[041] Advantageously, the present invention provides electrical safety for vehicle bound component and human. This also helps in reducing the Electromagnetic emission and better immunity to noise. The present invention further improves battery management, which ensures smooth and prolonged life for battery systems. The data logging by the telematics unit helps us in easily diagnosing failures in the vehicle. The present invention helps in ease of diagnosis during repairs.
[042] In the present invention two separate CAN buses between the BMS and the VCU, and the VCU and the speedometer/instrument cluster is avoided and only one CAN bus between the batteries till the speedometer/instrument cluster is provided. The motor control unit and the motor drive unit are part of another separate CAN bus and interact with the CAN bus via the secondary communication line.
[043] The present invention achieves reduction of EMC levels and better immunity. This is due to the fact that the present invention includes a rigid wiring harness or bus bars which significantly reduces the EMC levels of the vehicle. In the present invention, the critical signal lines and the 48V power lines are separately routed to reduce the effect on them. The present invention involves a better battery management since there are four batteries, each with its own or a separate Battery Management System. The BMS monitors the health of all the batteries by continuously monitoring the cell voltage and current discharge levels and indicates the same. Also, the BMS regulates the charging of the batteries.
[044] In the present invention, the CAN bus eases the diagnosis of any kind of fault because, all the telematics data is continuously communicated to the telematics unit. The data logs helps in diagnosis of any vehicle failure. Also, error codes for different faults are being displayed on the instrument cluster for diagnosis of problems.
[045] The present invention ensures electrical safety of the vehicle. This is due to isolated signal lines and 48V power lines that provide immunity against noise and safety. Also, the separate grounding of the front, rear harness and motor bus bar and auxiliary battery provides the electrical safety. In other words, signal lines, high voltage lines and low voltage lines are isolated from each other through separate grounds. Further, as the electrical system include one CAN bus between the BMS, the VCU and Speedometer/telematics and another CAN bus between the MCU and the motor, the safety in the electrical system is improved. Furthermore, as the batteries are connected on the bus bar and there is no master slave architecture in communication between BMS of each battery, the electrical safety is improved.
[046] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.