Hybrid vehicle battery maintenance system

Abstract

A battery maintenance system for a vehicle includes: a battery mounted to the vehicle, the battery having a charge level; an electric motor connected to a ground engaging member of the vehicle; a hybrid power source mounted to the vehicle and at least partially configured to provide power to the battery to power the electric motor; and a control module mounted to the vehicle, the control module configured to detect the battery when the vehicle is in a dormant state, determine whether a charge level of the battery is above a minimum level, and if not above the minimum level, determine whether the charge level of the battery is below the minimum level. If so, the hybrid power source is activated to deliver power to the battery at least until the charge level of the battery is above the minimum level.

Description

Technical Field

[0001] The present disclosure relates generally to work machines and, more particularly, to battery systems for work machines. Background Art

[0002] Mobile work machines such as dump trucks, excavators, crawler tractors, etc. may be used in heavy industries such as mining, construction, etc. to transport materials and personnel. These work machines are generally large in size and require an operator such as a driver to manually operate the machine so that the machine performs its designated / intended operation.

[0003] Some working machines may be hybrid vehicles, in other words, powered by a hybrid powertrain. A hybrid vehicle uses a conventional internal combustion engine and an electric motor powered by a battery. The battery is continuously recharged by the internal combustion engine, for example by connection to a generator. A hybrid vehicle can operate in one of two ways. First, a hybrid vehicle can operate in a parallel design, where the energy conversion unit and the electrical propulsion system are directly connected to the wheels of the vehicle. The internal combustion engine is primarily used for driving, while the electric motor provides increased power when energy enhancement is needed. Second, a hybrid vehicle can operate in a serial design, where the internal combustion engine is connected to a generator to generate electrical energy to charge the battery of the electric motor. The electric motor then powers the wheels of the vehicle. Many hybrid vehicles are also able to use regenerative braking to store and convert energy that is normally lost through braking and deceleration into useful power.

[0004] Plug-in vehicles are essentially hybrid vehicles with the added advantage of a larger battery and the ability to be recharged externally at a power source.

[0005] A fuel cell electric motor (FCEM) is able to generate electrical energy by using hydrogen to react with oxygen in a fuel cell, and the electrical energy can be used to charge a battery, which in turn powers an electric motor. The hydrogen can be present in the battery or can be converted from another fuel. The hydrogen produced can also be stored in a gas tank in the car. The fuel cell generates the average power required to drive the vehicle on the highway, while the battery and supercapacitor provide transient power. The FCEM has virtually no emissions.

[0006] Work machines, particularly those powered by hybrid powertrains, may require a high voltage battery pack to provide power to the work machine. Large work machines may require large amounts of power, and therefore, the battery pack may be configured to deliver power in various capacities such as 750 volts, 1500 volts, or any other capacity known and desired.

[0007] The work machine may be operated as part of a fleet. Often, an individual work machine may be in a standby mode or dormant state for months at a time, in which the work machine's minimal systems are powered. Over time, the hybrid work machine's battery pack may drain power to feed the work machine's systems while in its dormant state. Cold weather may affect the discharge of the battery pack more quickly.

[0008] What is needed is a system within a work machine that monitors the state of charge of a battery pack and generates electrical power to charge the battery pack if the state of charge drops below a desired level. Summary of the invention

[0009] According to one aspect of the present disclosure, a vehicle may be provided. The vehicle may have a frame, a power source supported by the frame, a control module configured to control the operation of the vehicle, and a battery for providing power to the vehicle, the battery having a charge level. The vehicle may have a battery maintenance system configured to identify that the vehicle is in a dormant state, and based on identifying that the vehicle is in a dormant state, detect the battery via the control module. The battery maintenance system may determine whether the charge level of the battery is not above a minimum level based on detecting the battery. The battery maintenance system may activate the power source based on determining that the charge level of the battery is not above the minimum level to deliver power to the battery, at least until the charge level of the battery is above the minimum level.

[0010] According to another aspect of the present disclosure, a battery maintenance system for a vehicle is provided. The battery maintenance system may include a battery mounted to the vehicle, the battery having a charge level. The battery maintenance system may include an electric motor connected to a ground engaging member of the vehicle; and a hybrid power source mounted to the vehicle and at least partially configured to provide power to the battery to power the electric motor. The battery maintenance system may include a control module mounted to the vehicle, the control module configured to detect the battery when the vehicle is in a dormant state, determine whether the charge level of the battery is above a minimum level, and if not above the minimum level, activate the hybrid power source to deliver power to the battery, at least until the charge level of the battery is above the minimum level.

[0011] According to yet another aspect of the present disclosure, a method for charging a battery in a vehicle. The method may include monitoring the state of charge of the battery while the vehicle is at rest, the vehicle including a hybrid powertrain including one or more electric motors and a power source, both connected to the battery. The method may include determining that the state of charge of the battery is above a minimum level while the vehicle is at rest, the vehicle then remaining at rest. The method may include determining that the state of charge of the battery is below the minimum level after determining that the state of charge of the battery is above the minimum level and after the vehicle remains at rest. The method may include activating the power source to generate electricity. The method may include charging the battery via the power source at least until the state of charge of the battery is above the minimum level.

[0012] These and other aspects and features of the present disclosure will be more readily understood when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a perspective view of a work machine constructed in accordance with an embodiment of the present disclosure.

[0014] Figure 2 is a schematic block diagram depicting an electrical system of a work machine having a hybrid powertrain including a fuel cell electrical system constructed in accordance with an embodiment of the present disclosure.

[0015] Figure 3 is a schematic block diagram depicting an electrical system of a work machine having a hybrid powertrain including a hydrogen internal combustion engine constructed in accordance with an embodiment of the present disclosure.

[0016] Figure 4 is a flow chart depicting a sample sequence of steps for operating a battery management system of a vehicle in which a work machine according to the present disclosure may be practiced. DETAILED DESCRIPTION

[0017] Now refer to the accompanying drawings and specifically refer to Figure 1 , a work machine is depicted and generally indicated using the reference numeral 10. Work machine 10 is illustratively embodied in the form of a mining truck. Although work machine 10 is depicted as a mining truck, it should be noted that the type of machine used is merely exemplary and illustrative in nature. It should be recognized that the teachings of the present disclosure can be similarly applied to other types of work machines, including but not limited to automobiles, on-highway and off-highway trucks, excavators, crawler tractors, and other types of machines having hybrid powertrains known to those skilled in the art.

[0018] A work machine is a heavy machine that can be configured to perform a variety of tasks. Exemplary work machine 10 is supported by frame 11. Work machine 10 may include a transmission system 12, which is powered by engine 13 and drives ground engaging members 14 to contact the ground and support frame 11 to operate work machine 10. Work machine 10 may also include implements 15 for performing work tasks. Figure 1 In the view of FIG. 1 , since the work machine 10 is a mining truck, the implement 15 is exemplarily depicted as a dump body, but for other machines, the implement may be other types of work implements known to those skilled in the art. The work machine 10 may also include an operator compartment 16 for an operator to control the operation of the work machine 10. The operator compartment 16 may include a control module 17 for the operator to command the work machine 10. The work machine may also include a battery pack 18 to power the electrical system of the work machine 10.

[0019] Figure 2 An exemplary block diagram of the main electrical system 20 of the work machine 10 is depicted when the work machine 10 is powered by a hybrid powertrain. Figure 2 In the main electrical system 20 of the invention, the hybrid system is a series fuel cell electric hybrid system (FCEM), including a battery pack 18 and a fuel cell 22. The fuel cell 22 may be composed of one or more fuel cells, and Figure 2 A fuel cell 22 is depicted.

[0020] The battery pack 18 is connected to a battery management system 21 (BMS), which may be connected to a battery converter 23 to provide constant voltage power to a control module 25. Figure 2 In an exemplary embodiment of the present invention, the battery converter 23 is a direct current to direct current (DC / DC) converter, but other converters may be required as needed. The control module 25 may include: a power distribution unit (PDU) or power delivery unit (e.g., without software components); one or more electronic control units (ECUs) including software and / or logic capabilities to interface the battery management system 21 with one or more communication and / or information components associated with the vehicle (e.g., one or more sensors, such as a hydrogen level sensor); and / or other control modules.

[0021] Similar to the battery pack 18, each of the fuel cells 22 can be connected to a fuel cell converter 24 to provide additional power to the control module 25. Like the battery converter 23, the fuel cell converter 24 can be a direct current to direct current (DC / DC) converter, but other converters may be required as needed. As shown in the main embodiment, the control module 25 can be configured to receive power from the fuel cell 22 only through the fuel cell converter, and can be configured to both send power from the battery pack 18 through the battery converter 23 and receive power from the battery pack through the battery converter.

[0022] Optionally, the main electrical system 20 of the working machine 10 may be provided with a charging system to supply power to the working machine 10 from an external source. A charging port 26 may be provided on the working machine 10 and may be configured to be connected to a known common electrical connector. The charging port 26 may be configured to send power to the control module 25 via a direct current (DC) or alternating current (AC) electrical signal. In order to convert the AC power signal into a DC power signal for the control module 25, a charging module 27 may be placed between the charging port 26 and the control module 25. The charging module 27 may be configured to detect the power signal entering the charging port 26 and convert the AC signal into a DC signal suitable for the control module 25.

[0023] The control module 25 can be configured to send power generated from the battery pack 18 and the fuel cell 22 to a plurality of electrical subsystems. The control module 25 can send power to the operator cab 16 through the cab converter 28 for operator comfort systems, such as a cab heater 29 or an HVAC compressor 30. The control module 25 can send power to a traction motor inverter 31, which can send and receive power from a traction electric motor 32. The traction motor inverter 31 can send any excess power generated from the traction electric motor 32 back to the control module 25. The control module 25 can also send and receive power from an implement motor inverter 33, which in turn can send power to an implement electric motor 34.

[0024] The control module 25 can also be configured to send power to a subsystem converter 35, which can also be configured to distribute power to other components of the working machine 10, such as a lead-acid battery 36, a cooling fan 37, a water pump 38, a lubricating oil pump 39, an engine control module 40, a fuel cell controller 41 and a battery temperature management system 42.

[0025] Figure 3 Another exemplary block diagram of the main electrical system 50 of work machine 10 is depicted when work machine 10 is powered by a hybrid powertrain. Figure 3In the main electrical system 50 , the hybrid system is a series internal combustion hybrid system including a battery pack 18 and a hydrogen internal combustion engine 43 .

[0026] The main electrical system 50 having a series type internal combustion hybrid system is similar to the Figure 2 The main electrical system 20 is shown. Similar to the main electrical system 20, the control module 25 of the main electrical system 50 can be configured to send and receive power delivered by the battery converter 23 through the battery pack 18 controlled by the battery management system 21. The control module 25 can also receive power through the charging port 26 and the charging module 27.

[0027] The control module 25 of the main electrical system 50 may also be configured to send power to the operator cab 16 through the cab converter 28 for operator comfort systems, such as the cab heater 29 or the HVAC compressor 30. The control module 25 may also be configured to send power to the subsystem converter 35, which may also be configured to distribute power to other components of the work machine 10, such as the lead-acid battery 36, the cooling fan 37, the water pump 38, the lubrication oil pump 39, the engine control module 40, and the battery temperature management system 42.

[0028] The control module 25 of the main electrical system 50 can also send and receive power from the traction motor inverter 31, which can send and receive power from the traction electric motor 32. The hydrogen internal combustion engine 43 can be connected to the generator 45 by the shaft 44, and the generator can send and receive power from the traction motor inverter 31. The energy generated by the hydrogen internal combustion engine 43 can also be partially used by the first hydraulic pump 46 and the second hydraulic pump 47.

[0029] When Figure 2 When the main electrical system 20 depicted in FIG. 1 is in operation, the battery pack 18 may receive power from the fuel cell 22 sent through the fuel cell converter 24, the control module 25, and the battery converter 23. Figure 3 When the primary electrical system 50 depicted in FIG. 1 is in operation, the battery pack 18 may receive electrical power from the hydrogen internal combustion engine 43 connected by shaft 44 to the generator 45 , routed through the traction motor inverter 31 , the control module 25 , and the battery converter 23 .

[0030] Industrial Applicability

[0031] In operation, the teachings of the present disclosure may be applied to many industries, including but not limited to work machines used in the earth moving, mining, agricultural and construction industries. Although depicted and described in conjunction with a mining machine, such teachings may also be applicable to other machines, such as automobiles, on-highway and off-highway trucks, excavators, crawler tractors, and other types of machines having hybrid powertrains.

[0032] Figure 4 A visual representation of a method 100 for charging a battery pack 18 of a work machine 10 is shown, particularly when the work machine 10 is in a rest or dormant state. In a first step 101, the work machine 10 is placed in a rest or dormant state. The control module 25 of the work machine 10 may discharge power to limited subsystems of the work machine 10, thereby draining power from the battery pack 18. A battery management system 21 connected to the battery pack 18 continuously monitors the state of charge of the battery pack 18 and determines in a second step 102 whether the state of charge of the battery pack 18 is above a certain minimum level. In a third step 103, the battery management system 21 determines that the state of charge is above the minimum level and prompts the control module 25 in a fourth step 104 to remain in the dormant state or re-enter the dormant state. If in a fifth step 105, the battery management system 21 determines that the state of charge is not above the minimum level, the battery management system 21 prompts the control module 25 to communicate with the work machine 10 to determine the fuel level. The work machine 10 is partially powered by a fuel cell 22 or a hydrogen internal combustion engine 43 and therefore requires fuel in the form of hydrogen stored in a hydrogen tank.

[0033] In a sixth step 106, the control module 25 determines the hydrogen level based on a hydrogen level sensor connected to the hydrogen tank of the work machine 10, and the battery management system 21 determines whether the hydrogen level is above the hydrogen target. Although the work machine 10 of the method 100 is shown as being provided with hydrogen as a fuel source, similar power sources utilizing other known fuel types may be provided. In a seventh step 107, the battery management system 21 determines that the hydrogen level is sufficient, and in an eighth step 108, the control module 25 is prompted to send power to the battery pack 18 until the battery management system 21 determines that the state of charge of the battery pack 18 is above a minimum level.

[0034] The battery management system 21 may determine in the ninth step 109 that the hydrogen level of the work machine 10 is not above the hydrogen target. Then, in the tenth step 110, the battery management system 21 prompts the control module 25 to send a message to the operator that the battery pack 18 has a low state of charge and the hydrogen level is too low to assist in charging the battery pack 18. After sending the message, in the eleventh step 111, the battery management system 21 prompts the control module 25 to bring the work machine 10 out of the sleep state and undergo a shutdown procedure.

[0035] The method 100 of charging the battery pack 18 of the work machine 10 facilitates maintaining the work machine 10 at a level that is immediately ready for operation on site. Utilizing the fuel cell 22 or hydrogen internal combustion engine 43 to charge the battery pack 18 while the work machine 10 is not operating and in its dormant state allows for less downtime of the work machine 10 to charge the battery pack 18 or replace the battery pack 18 with a battery pack having a new charge.

[0036] It is obvious that the present disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teachings contained in the present disclosure. Therefore, the present invention is not limited to the specific details of the present disclosure, except where the following claims must be so limited.

Claims

1. A battery maintenance system for a vehicle, comprising: a battery mounted to the vehicle, the battery having a charge level; an electric motor connected to a ground engaging member of the vehicle; a hybrid power source mounted to the vehicle and configured at least in part to provide power to the battery to power the electric motor; a control module mounted to the vehicle, the control module being configured to probe the battery when the vehicle is in a dormant state, determine whether a charge level of the battery is above a minimum level, and if not above the minimum level, activate the hybrid power source to deliver power to the battery at least until the charge level of the battery is above the minimum level.

2. The battery maintenance system of claim 1, wherein the hybrid power source includes a fuel tank having a fuel level and a fuel level sensor connected to the fuel tank to obtain the fuel level.

3. The battery maintenance system of claim 2, wherein the control module is connected to the fuel level sensor and is configured to detect the fuel level sensor and alert an operator if both the charge level is not above the minimum level and the fuel level is not above a fuel target.

4. The battery maintenance system of claim 3, wherein the hybrid power source is one of an internal combustion engine or a fuel cell electrical system.

5. The battery maintenance system of claim 1, wherein the battery is a 24 volt battery or a high voltage battery.

6. A method for charging a battery in a vehicle, the method comprising: monitoring a state of charge of the battery while the vehicle is at rest, the vehicle including a hybrid powertrain including one or more electric motors and a power source, both connected to the battery; determining that the state of charge of the battery is above a minimum level when the vehicle is in the rest state, the vehicle then remaining in the rest state; after determining that the state of charge of the battery is above the minimum level and the vehicle remains in the rest state, determining that the state of charge of the battery is below the minimum level; activating the power source to generate electricity; as well as The battery is charged via the power source at least until a state of charge of the battery is above the minimum level. 7 . The method of claim 6 , further comprising determining a fuel level of the vehicle after determining that the state of charge of the battery is below the minimum level, and activating the power source only when the fuel level is above a fuel target. 8 . The method of claim 7 , further comprising determining that a fuel level of the vehicle is below the fuel target, and alerting an operator based on determining that the fuel level of the vehicle is below the fuel target.

9. The method of claim 8, wherein the power source comprises an internal combustion engine or a fuel cell electrical system. 10 . The method of claim 8 , further comprising performing a vehicle shutoff based on determining that a fuel level of the vehicle is below the fuel target.

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