Patent Application
20230402665
The subject disclosure relates to batteries and battery assemblies, and more particularly to charging batteries and battery assemblies using solar energy.
Vehicles, including gasoline and diesel power vehicles, as well as electric and hybrid electric vehicles, feature battery storage for purposes such as powering electric motors, electronics and other vehicle subsystems. Battery assemblies may be charged using dedicated charging stations and other power sources such as residences and building connected to a power grid. Solar energy can be employed to charge the batteries, for example, by installing solar panels on exterior vehicle components. Efficient use of solar energy can be challenging due to factors that include the variable nature of solar energy and voltage differences between solar panels and vehicle battery packs.
In one exemplary embodiment, a solar energy charging system of a vehicle includes a dynamically adjustable battery (DAB) configured to be connected to a solar energy conversion device and charged by the solar energy conversion device. The DAB is controllable to adjust an output voltage of the DAB to one of a plurality of output voltages, and the DAB is configured to supply electrical power generated by the solar energy conversion device to a vehicle battery assembly. The solar energy charging system also includes a controller configured to detect an input voltage to the solar energy conversion device, select an output voltage of the DAB based on the input voltage, and control the DAB to provide the selected output voltage to a high voltage DC-DC converter to charge the battery assembly.
In addition to one or more of the features described herein, the DAB includes a plurality of controllable switches, and the controller is configured to operate the switches to cause the DAB to output the selected voltage.
In addition to one or more of the features described herein, each voltage of the plurality of output voltages is less than a vehicle battery assembly voltage.
In addition to one or more of the features described herein, the system further includes a low voltage DC-DC converter configured to convert the input voltage to a low voltage value, where the controller is configured to select the output voltage based on the low voltage value.
In addition to one or more of the features described herein, the selected output voltage has a value that is closest to a value of the input voltage.
In addition to one or more of the features described herein, the controller is configured to measure a state of charge of the DAB, receive solar information indicative of a level of solar intensity, and select the output voltage based on the state of charge being below a threshold state of charge value and the level of solar intensity being at or above an intensity threshold value.
In addition to one or more of the features described herein, the solar information includes at least one of a measured input voltage from the solar energy conversion device, a measured solar intensity, and an estimated solar intensity derived from climate and weather information.
In addition to one or more of the features described herein, the controller is configured to measure a state of charge of the DAB, and receive solar information indicative of a level of solar intensity, and based on the state of charge being below a threshold state of charge value and the level of solar intensity being below an intensity threshold value, connect the DAB to the vehicle battery assembly to cause the vehicle battery assembly to charge the DAB.
In addition to one or more of the features described herein, the controller is configured to control the DAB to supply power to one or more additional vehicle components.
In another exemplary embodiment, a method of transferring charge includes connecting a dynamically adjustable battery (DAB) to a solar energy conversion device and to a vehicle battery assembly. The DAB is configured to be charged by the solar energy conversion device, and the DAB is controllable to adjust an output voltage of the DAB to one of a plurality of output voltages. The method also includes detecting, by a controller, an input voltage to the solar energy conversion device, selecting an output voltage of the DAB based on the input voltage, and controlling the DAB to provide the selected output voltage to a high voltage DC-DC converter to charge the battery assembly.
In addition to one or more of the features described herein, each voltage of the plurality of output voltages is less than a vehicle battery assembly voltage.
In addition to one or more of the features described herein, the method further includes supplying charge to the DAB from the solar energy conversion device.
In addition to one or more of the features described herein, supplying the charge includes converting the input voltage by a low voltage DC-DC converter to a low voltage value, and the output voltage is selected based on the low voltage value.
In addition to one or more of the features described herein, the selected output voltage has a value that is closest to a value of the input voltage.
In addition to one or more of the features described herein, the method further includes measuring a state of charge of the DAB and receiving solar information indicative of a level of solar intensity, where the output voltage is selected based on the state of charge being below a threshold state of charge value and the level of solar intensity being at or above an intensity threshold value.
In addition to one or more of the features described herein, the solar information includes at least one of a measured input voltage from the solar energy conversion device, a measured solar intensity, and an estimated solar intensity derived from climate and weather information.
In addition to one or more of the features described herein, the method further includes, based on the state of charge being below a threshold state of charge value and the level of solar intensity being below an intensity threshold value, connecting the DAB to the vehicle battery assembly and causing the vehicle battery assembly to charge the DAB.
In yet another exemplary embodiment, a vehicle system includes a solar energy conversion device, a battery assembly, and a solar energy charging system. The solar energy charging system includes a dynamically adjustable battery (DAB) configured to be connected to a solar energy conversion device and charged by the solar energy conversion device. The DAB is controllable to adjust an output voltage of the DAB to one of a plurality of output voltages, and the DAB is configured to supply electrical power generated by the solar energy conversion device to a vehicle battery assembly. The solar energy charging system also includes a controller configured to detect an input voltage to the solar energy conversion device, select an output voltage of the DAB based on the input voltage, and control the DAB to provide the selected output voltage to a high voltage DC-DC converter to charge the battery assembly.
In addition to one or more of the features described herein, the solar energy charging system further includes a low voltage DC-DC converter configured to convert the input voltage to a low voltage value, where the controller is configured to select the output voltage based on the low voltage value.
In addition to one or more of the features described herein, the selected output voltage has a value that is closest to a value of the input voltage.
The above features and advantages, and other features and advantages of the disclosure are readily apparent from the following detailed description when taken in connection with the accompanying drawings.
Other features, advantages and details appear, by way of example only, in the following detailed description, the detailed description referring to the drawings in which:
The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
In accordance with one or more exemplary embodiments, methods, devices and systems are provided for transferring charge or energy to a vehicle battery assembly and/or other vehicle components from a solar energy conversion device. An embodiment of a solar energy charging system includes a secondary variable voltage battery having a configurable or selectable output voltage, referred to herein as a dynamically adjustable battery (DAB). The DAB is configured to be connected to the solar energy conversion device (e.g., one or more solar panels or panel arrays) and charged by the solar energy conversion device. The DAB is controllable to adjust the output voltage based on an input voltage from the conversion device to increase charging efficiency.
Embodiments described herein present numerous advantages and technical effects. For example, the embodiments provide for an efficient mechanism to charge a vehicle battery system using solar energy. Existing charging systems often include DC-DC converters. As there is often a large variation in solar intensity, there can be a significant mismatch between inputs to and outputs from a DC-DC converter, which can significantly impact the charging efficiency and lead to losses. Embodiments described herein address such challenges and increase the efficiency of solar energy charging systems.
The embodiments are not limited to use with any specific vehicle or device or system that utilizes battery assemblies, and may be applicable to various contexts. For example, embodiments may be used with automobiles, trucks, aircraft, construction equipment, farm equipment, automated factory equipment and/or any other device or system that may use high voltage battery packs or other battery assemblies.
The vehicle 10 may be a combustion engine vehicle, an electrically powered vehicle (EV) or a hybrid electric vehicle (HEV). In an example, the vehicle is a hybrid vehicle that includes a combustion engine assembly 18 and an electric motor assembly 20.
The vehicle 10 includes a battery system 22, which may be electrically connected to the motor assembly 20 and/or other components, such as vehicle electronics. In an embodiment, the battery system 22 includes a battery assembly such as a high voltage battery pack 24 having a plurality of battery modules 26. Each of the battery modules 26 includes a number of individual cells (not shown). The high voltage battery pack 24 is, for example, a 400 Volt (V) or 800 V battery pack.
In an embodiment, the battery assembly 22 is configured as a rechargeable energy storage system (RESS), and includes sensors 28 and a controller Each sensor 28 may be an assembly or system having one or more sensors for measuring various battery and environmental parameters, such as temperature, current and voltage. The controller 30 includes components such as a processor, memory, an interface, a bus and/or other suitable components.
The vehicle 10 also includes a solar energy charging system 32 configured for charging the battery pack 24 with energy from one or more solar energy conversion devices (not shown, see
The solar energy charging system 32 is configured to be directly charged by the conversion device(s), and is provided to increase efficiency and reduce power losses associated with solar energy charging. The DAB 34 can be adjusted to reduce a difference between a voltage generated by the solar energy conversion devices (“input voltage” or “solar panel voltage”) to reduce a difference between the input voltage and output voltage of a charging component or components, such as a DC-DC converter. The reduction increases charging efficiency and reduces the amount of hardware that would otherwise be needed to boost the solar panel voltage to battery pack levels.
The vehicle 10 also includes a computer system 40 that includes one or more processing devices 42 and a user interface 44. The various processing devices and units may communicate with one another via a communication device or system, such as a controller area network (CAN) or transmission control protocol (TCP) bus.
The ECU 50, the controller 36, the DAB 34 and/or other components may be incorporated into one or more modules that can be installed in the vehicle 10 and removed as desired. For example, the ECU 50 and the DAB 34 are modules that can be removably connected to the battery system 22 and the solar panel arrays 48. Embodiments are not so limited and can be incorporated into the vehicle 10 in any suitable manner.
As discussed further herein, the controller 36 and/or ECU 50 is configured to adjust the output voltage of the DAB 34 based on a determined solar panel voltage. The solar panel voltage may be determined by directly detecting the solar panel voltage and providing a solar panel voltage value to the controller 36. Alternatively, or additionally, the solar panel voltage can be estimated based on solar intensity, which can be measured directly or estimated based on other information (e.g., the time of day and year, climate information, weather information, etc.). For example, a solar intensity or light sensor 52 may be mounted at one or more locations on the vehicle 10, such as on the front hood as shown in
The solar panel arrays 48 are connected to a low voltage DC-DC converter 58 that is configured to step up or step down the solar panel voltage to a selected voltage value. The selected voltage value may be based on the solar panel voltage. For example, the low voltage DC-DC converter 58 converts input voltages from the solar panel arrays 48 to 12V or 48V, depending on the input voltage levels.
During charging, the low voltage DC-DC converter 58 steps input voltage up or down, and the DAB 34 is adjusted (e.g., by controlling switches) to select one of a plurality of voltage settings. In each voltage setting, the DAB 34 is configured to output one of a plurality of different output voltages. For example, the DAB 34 can have a 12V setting and a 24V setting. The voltage setting that is closest to the input voltage from the solar panel arrays 48 is selected. In this mode, the DAB is disconnected from the high voltage DC-DC converter 54 and from the battery pack 24.
Referring to
It is noted that the DAB 34 can be charged in other ways. For example, the DAB 34 can be selectively connected to the combustion engine assembly 18 or alternator (e.g., if the vehicle 10 is a HEV), or connected to a charge port and charged via a charging station or other power supply (e.g., residential outlet, power grid, etc.)
The method 70 includes a number of steps or stages represented by blocks 71-77. The method 70 is not limited to the number or order of steps therein, as some steps represented by blocks 71-77 may be performed in a different order than that described below, or fewer than all of the steps may be performed.
At block 71, parameters of the battery pack 24, the DAB 34 and the solar panel arrays 48 are monitored. For example, the battery pack 24 state of charge, and parameters including voltage and current of the solar panel arrays 48 are measured. In addition, parameters of the DAB 34, including state of charge and voltage setting, are determined. Additional parameters may be measured as desired. Measurements may be performed continuously, periodically or otherwise.
At block 72, the controller 36 determines whether the DAB 34 state of charge (SOC) is at or above a selected SOC threshold. If so, at block 73, the DAB 34 is put into the battery pack charging mode by connecting the DAB 34 to the battery pack 24, and charge is transferred to the battery pack 24 if needed or desired.
At block 74, if the DAB 34 SOC is below the SOC threshold, the controller 36 determines whether the output of the solar panels is sufficient for charging the DAB 34. This may be determined, for example, by measuring the solar panel voltage and current, and/or based on estimating solar intensity (e.g., via the sensor 52 or climate and weather information). The output from the solar panel arrays 48 is sufficient, for example, if the solar panel array voltage and/or solar intensity is at or above a respective threshold.
At block 75, if the solar panel array output is sufficient, the DAB 34 is put into the DAB charging mode and is charged by the solar panel arrays 48. The voltage setting of the DAB 34 is selected as the setting having a voltage that is closest to the solar panel array voltage. It is noted that the DAB 34 voltage setting can be dynamically changed in real time or near real time as the solar panel voltage changes.
At block 76, the controller 36 determines whether the battery pack 24 SOC is below a selected SOC threshold. If so, at block 77, charge may be transferred from the battery pack 24 to the DAB 34 if desired (e.g., if the DAB 34 SOC is low).
The method 80 includes a number of steps or stages represented by blocks 81-85. The method 80 is not limited to the number or order of steps therein, as some steps represented by blocks 81-85 may be performed in a different order than that described below, or fewer than all of the steps may be performed.
The method 80 may be performed as part of an overall monitoring and charge transfer method, such as the method 70. For example, the method 80 may be performed as part of blocks 74 and 75 of the method 70.
At block 81, parameters of the solar panel arrays 48 are measured. The parameters may include solar panel array voltage (V), current (I) and power (P).
At block 82, the solar panel array voltage is compared to the DAB 34 voltage settings, and the voltage setting that is closest to the solar panel array voltage is selected by controlling appropriate switches. For example, the DAB 34 is configured to have two voltage settings, including a 12V setting and a 24V setting.
Upon selection of the desired setting, current from the solar panel array 48 flows to the DAB 34 and charges the DAB 34.
At block 83, the DAB 34 is monitored by measuring the DAB 34 SOC during the charging process. The solar panel array parameters are repeatedly measured until the DAB 34 is fully charged, or if conditions change such that the solar panel output is no longer sufficient.
At block 84, upon determining that the DAB 34 is fully charged (or if conditions change as noted above), the DAB 34 is reset as necessary to put the DAB 34 to the highest available voltage setting. At block 85, the DAB 34 may then be used to charge the battery pack 24.
The cells 100, 102 and 104 are connected to various switches for putting the DAB 34 into different operating modes. The switches may be FETs or other suitable type. The cell 100 is connected to the LV bus 108 via a switch 110 and the cell 102 is connected to the LV bus 108 via a switch 112. The cell 102 is connected to the LV bus 108 via a switch 114 and the cell 104 is connected to the LV bus 108 via a switch 116. The cell 104 is connected to the LV bus 108 via switch 118 and the HV bus via a switch 120. Switches 122 and 124 selectively connect the cells 102 and 104 to ground.
It is noted that the DAB 34 can be put into an intermediate voltage state by closing fewer than all of the cells 100, 102 and 104. For example, the DAB 34 can be configured to output 24V by closing switches 120 and 116, and leaving the remaining switches open.
As discussed above, embodiments described herein increase the charging efficiency when a vehicle's battery assembly is charged using solar energy conversion devices.
The graph 90 shows charge efficiency (% of solar panel charge) for a DAB 34 having a 12V voltage setting (12 V output voltage) and a 6 A current output. The charge efficiency (Eff) is a function of solar panel input voltage (in Volts) and is shown by curve 92.
The graph 90 also shows power loss (in Watts) of DC-DC converter components. The total power loss (PL) of the DC-DC converter switches is shown by curve 94, inductor loss is shown by curve 96, and shunt loss is shown by curve 98. As can be seen, the charging efficiency increases, and the power loss reduces, as the input voltage from the solar panel arrays 48 gets closer to the DAB 34 output voltage setting. Thus, by controlling the DAB 34 as discussed herein to reduce the difference between the input voltage and the DAB voltage, charge efficiency can be significantly increased and power loss reduced.
Components of the computer system 140 include the processing device 142 (such as one or more processors or processing units), a memory 144, and a bus 146 that couples various system components including the system memory 144 to the processing device 142. The system memory 144 can be a non-transitory computer-readable medium, and may include a variety of computer system readable media. Such media can be any available media that is accessible by the processing device 142, and includes both volatile and non-volatile media, and removable and non-removable media.
For example, the system memory 144 includes a non-volatile memory 148 such as a hard drive, and may also include a volatile memory 150, such as random access memory (RAM) and/or cache memory. The computer system 140 can further include other removable/non-removable, volatile/non-volatile computer system storage media.
The system memory 144 can include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out functions of the embodiments described herein. For example, the system memory 144 stores various program modules that generally carry out the functions and/or methodologies of embodiments described herein. A module 152 may be included for performing functions related to monitoring system components, and a module 154 may be included to perform functions related to controlling charging operations as discussed herein. The system 140 is not so limited, as other modules may be included. As used herein, the term “module” refers to processing circuitry that may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
The processing device 142 can also communicate with one or more external devices 156 as a keyboard, a pointing device, and/or any devices (e.g., network card, modem, etc.) that enable the processing device 142 to communicate with one or more other computing devices. Communication with various devices can occur via Input/Output (I/O) interfaces 164 and 165.
The processing device 142 may also communicate with one or more networks 166 such as a local area network (LAN), a general wide area network (WAN), a bus network and/or a public network (e.g., the Internet) via a network adapter 168. It should be understood that although not shown, other hardware and/or software components may be used in conjunction with the computer system 40. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc.
While the above disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from its scope. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiments disclosed, but will include all embodiments falling within the scope thereof
