The present disclosure relates generally to a vehicle, and more particularly to a vehicle that utilizes solar power as an energy source and the management of the solar power distribution.
Vehicles, such as a motor vehicle, utilize an energy source in order to provide power to operate a vehicle. While petroleum based products dominate as an energy source, alternative energy sources are available, such as methanol, ethanol, natural gas, hydrogen, electricity, solar or the like. A hybrid powered vehicle utilizes a combination of energy sources in order to power the vehicle. Such vehicles are desirable since they take advantage of the benefits of multiple fuel sources, in order to enhance performance and range characteristics of the vehicle, as well as reduce environmental impact relative to a comparable gasoline powered vehicle.
An example of a hybrid vehicle is a vehicle that utilizes both electric and solar energy as power sources. An electric vehicle is environmentally advantageous due to its low emissions characteristics and general availability of electricity as a power source. However, battery storage capacity limits the performance of the electric vehicle relative to a comparable gasoline powered vehicle. Solar energy is readily available, but may not be sufficient by itself to operate the vehicle. Thus, there is a need in the art for a, hybrid vehicle with an improved photovoltaic energy distribution system.
Accordingly, the present disclosure relates to a solar energy charge and management system for a vehicle including a photovoltaic apparatus for receiving solar energy and converting the solar energy to electrical energy. The system includes a user interface for selecting a predetermined solar power mode and a controller operatively in communication with the user interface. The interface allows for selectively distributing energy from the photovoltaic apparatus to operate a vehicle component associated with the selected solar power mode.
An advantage of the present disclosure is user selectable solar charging modes are provided. Yet another advantage of the present disclosure is more efficient vehicle operation through energy distribution between low and high voltage energy storage devices is available. Still yet another advantage of the present disclosure is an external solar charge light indicator is provided. A further advantage of the present disclosure is that the system communicates with and stores energy within an energy storage device such as a battery. Still a further advantage of the present disclosure is that the energy generated from the solar panel can be stored for later distribution.
Other features and advantages of the present disclosure will be readily appreciated, as the same becomes better understood after reading the subsequent description taken in conjunction with the accompanying drawings.
Referring to the
The vehicle 10 also includes a power train that is operable to propel the vehicle 10. In this example, the power train is a plug-in hybrid, and includes an electrically powered motor and motor controller. The vehicle 10 may also include a gasoline powered engine that supplements the electric motor when required under certain operating conditions. The electrical energy can be stored in an energy storage device, such as a battery, to be described. Various types of batteries are available, such as lead acid, or lithium-ion or the like. It should be appreciated that the vehicle 10 may include more than one type of battery or energy storage device. The battery supplies the power in the form of electricity to operate various vehicle components. In this example, there is a low voltage battery 70 that provides electrical power to vehicle components (e.g., a typical 12 V lead acid battery) and a high voltage battery 72 (e.g. over 60 V traction battery) and in this example a 400 V traction battery that provides electrical power to an electric drive motor. The batteries 70, 72 may be in communication with a control system that regulates the distribution of power within the vehicle 10, such as to the electric drive motor, or a vehicle component or other accessories or the like. In this example, the high voltage battery receives electrical energy from a plug-in source and a gasoline engine, and the low voltage battery 70 receives electrical energy from the high voltage battery or a photovoltaic source in a manner to be described. In a further example, the high voltage battery 72 and the low voltage battery 70 can receive electrical energy from a solar source.
Referring to
The solar panel 14 is operable to collect radiant energy from the sun and convert the sun's energy into stored electrical energy that is available for use in the operation of the vehicle 10. The solar energy is available to supplement that of the other energy sources, such as a plug in source or fossil fuel of this example. The supplemental solar energy effectively increases the performance of the vehicle 10, i.e. increased electric range for use by another vehicle feature or accessory.
The solar panel 14 includes a plurality of solar cells 20 arranged in a solar array as shown in
The solar panel 14 is divided into four sections or modules 22 that form electrically separate zones. The solar cells 20 are position within each module in a predetermined arrangement or pattern, such as an array. For example, each module may contains a 5 by 4 array of cells. The modules 22 themselves are connected by cross connector 24, or bus bars as shown in
The solar panel 14 may be fabricated using various techniques, the selection of which is nonlimiting. In an example, the solar panel is fabricated from a glass panel having a laminate structure. In another example, the photovoltaic system can be mounted or incorporated within a composite structure, such as integrally formed within a polymer or composite material. The solar module may be laminated within a durable polymer, such as a scratch resistant polycarbonate. In a further example, the solar modules 22 are mounted in a thin film, such as amorphous silicon or the like. In an even further example, the photovoltaic system includes modules 22 that are formed in other exposed vehicle structures, such as in a window. An organic solar concentrators or specially dyed window may be used that channels light to solar cells at their edges. Accordingly, the solar panel structure will influence characteristics of the vehicle such as weight, cost, packaging or the like.
Referring to
The solar panel 14 is operatively in communication with a solar charging system 34. To maximize solar energy, and thereby offset fuel usage, the energy generated from the solar panel 14 is stored. Typically, the energy is stored in the low voltage battery 70. Further, the solar charging system 34 may operatively be in communication with a vehicle charging system in a manner to be described. Each of the modules 22 in the solar panel incorporate a maximum power point (MPP) tracking feature that maximizes power output for various solar radiation angles and partial shading conditions of the solar panel 14 in a manner to be described. This feature assumes that if one cell 20 in a particular module 22 is shaded from the sun, then the performance of other cells on the module can also be diminished. Since each module 22 is electrically separate and isolated from the other modules and thus independent, the energy collection operation of the other available modules 22 may be optimized.
Referring to
Each module 22 includes electrical lines that deliver the voltage to the converter 36. The energy storage device or battery 70 includes a positive terminal 71a and a negative terminal 71b. The voltage from the module 22 is delivered to the converter 36 through a positive voltage input line 79a and a negative voltage input line 79b. The output of the converter 36 includes a positive output voltage line 79c and a negative output voltage line 79d that correspond to positive terminal 71a and negative terminal 71b respectively.
Depending on the available sunlight with respect to the vehicle position, the solar modules 22, or photovoltaic modules, can experience partial or full shading. Shading of a single cell can cause performance of the corresponding module to decrease. For example, a 3% shading can cause a 25% reduction in power. To minimize partial shading losses, each module 22 is electrically isolated from the others. Each module 22 includes its own maximum power point (MPP) tracking. MPP is the point on the current-voltage (I-V) curve of a solar module 22 under illumination, where the product of current and voltage is maximum (Pmax, measured in watts). The points on the I and V scales which describe this curve point are named Imp (current at maximum power) and Vmp (voltage at maximum power).
If the solar panel has a compound curvature (i.e., curving in multiple directions as shown in
Referring to
The solar charging system 34 can further include an accessory power module (APM) 40 that communicates with a DC/DC converter 73 to either boost or reduce voltage in the bidirectional energy flow between the low voltage battery 70 and a high voltage battery 72. For example, the DC/DC converter 73 used between a high voltage 72 and a low voltage battery 70 either boosts or reduces voltage depending on which direction the energy is flowing. The APM 40 monitors the energy flow to communicate with the solar charging system 34 to optimize energy distribution to the batteries 70 and 72.
The solar charging system 34 can further include a battery electronic control module (BECM) 42 that monitors the status and controls state of charge of the high voltage battery 72. It is understood, however, that the BECM 42 can be made to monitor the status and control states of charge for multiple energy storage devices, for example, the low voltage battery 70 and the high voltage battery 72. In a further example, alternative energy storage devices can be used such as a capacitor, multiple low voltage batteries, and the like. The solar charging system 34 includes a HCU 44, which is a controller that controls the high voltage contactors (not shown), such as the high voltage interlock. The HCU 44 may interface with other controllers, such as the vehicle control module (VCM) 46, APM 40, BMS 38, and/or BECM 42. The resulting charge is a steady state output. The VCM 46 manages the distribution of power between the photovoltaic apparatus 14, high voltage battery charging system, and electric motor.
Energy converted from the solar panel 14 can be used to charge the low voltage battery 70. Battery 70 can be used to further charge the high voltage battery. In an example, the low voltage battery is maintained below a predetermined threshold voltage in order to continuously receive energy form the solar panel 14. Accordingly, the vehicle 10 can be programmed to operate efficiently based on predetermined parameters and energy distribution between the photovoltaic apparatus 14, the low voltage battery 70, and the high voltage battery 72.
Referring to
In an example, a 12 V battery 70 is used as the low voltage battery 70. Battery 70 converts electrical energy to chemical potential energy for storage, and converts chemical potential energy to electric energy for use by devices. An example device, such as HVAC fan 110 uses electrical energy to serve various functions. The fan 110 can be powered by the boost converter 36 directly or by the 12V battery 70. In an example, controllers (VCM 46, HCU 44, APM 40, etc.) are used that communicate with various systems, store, and process data to control components. In a further example, a touch panel 112 is provided in the vehicle that allows users to interact with the photovoltaic system 14, e.g. to select how solar energy is used—for HVAC, charging, etc. It also displays information about the system's operation. Sensors, for example temperature sensor 113 connected to the HVAC controller 111, provide input to controllers to influence system operation. For example, in a certain mode, the vehicle may use solar power directly for ventilation rather than for charging if the cabin temperature rises above a threshold.
In an example, the low voltage battery 70 is depleted to a minimal acceptable state of charge (SOC) and caused to maintain that minimal level when the vehicle is on. This leaves more capacity to charge when the vehicle is off, thus increasing the utility of the photovoltaics and offsetting more fuel. If the battery 70 were maintained close to maximum SOC, the solar energy would only serve to maintain charge and not fully utilized for example with the high voltage battery 72.
In addition the high voltage battery 72 may be charged by the low voltage battery 70 which is continuously receiving energy from the photovoltaic apparatus 14. Generally, solar power is unlikely operable to maintain high voltage charging directly. Certain components like high voltage contactors may have a minimum threshold power to engage that the photovoltaic system 14 may not meet on its own. Accordingly, photovoltaics charge the low voltage battery continuously via DC/DC converter with MPP tracking until it reaches a threshold (such as almost full capacity), at which point the low voltage battery charges the high voltage battery via a boost converter at peak efficiency (relatively high power) until the low voltage battery reaches its minimum threshold, at which point high voltage charging ceases and low voltage photovoltaic charging continues. This process can repeat long as photovoltaic energy is available. Whereas a photovoltaic apparatus may only generate 130 W, a low voltage battery 70 may be able to boost to high voltage at 600 W via a boost converter 73 between the low voltage battery 70 and high voltage battery 72.
In an example, the high voltage battery is charged from the photovoltaic system via the bidirectional DC/DC converter as shown in
In an example, the bidirectional converter 73 typically does not boost and buck simultaneously. Accordingly, the solar panel 14 does not charge the high voltage battery 72 while the high voltage battery 72 powers low voltage components or when the low voltage battery 70 is charging. Accordingly energy paths 141 and 142 are mutually exclusive. For a system with a relatively small low voltage battery 70, this may mean that the system cannot capture solar energy while the vehicle is on. This would, however, only reduce the utility of the photovoltaic system marginally because often, solar charging occurs when the vehicle is parked. For a system with a normal or large low voltage battery 70, solar charging can still take place while the vehicle is on: Low voltage systems can run on energy stored in the low voltage battery 70, and the converter 73 can switch tasks to charge the low voltage battery periodically as necessary. In this scenario, the system only neglects potential solar energy when charging the low voltage battery 70. The system may include a direct connection to the low voltage bus 150 (no converter) from the photovoltaics 14, which the photovoltaic system 14 would switch to automatically when advantageous across switches 151. Accordingly, when voltage is sufficient to meet the requirements of the low voltage bus 150 (e.g. to charge the low voltage battery, as in
In an example the solar charging system can include several solar power modes that may be dependent on the vehicle operating condition. It should be appreciated that the selection of the solar power mode may influence the high or low battery charge state. For example, when the vehicle is turned on and is capable of propulsion or when the vehicle's electrical systems are on but the vehicle propulsion system is not on (i.e., accessories enabled), the electrical system of the vehicle may automatically utilize most of the available solar power. This energy distribution can be automatic without user input. The vehicle operator may selectively choose the solar power strategy for when the vehicle is turned off. For example, the user chooses a solar power distribution strategy prior to turning off the vehicle such that when the vehicle absorbs light while idle it can distribute the energy to desired components. The solar power distribution strategies can be classified as operating modes including “auto” mode, “charging” mode, or “climate” mode. The “auto” mode may use the solar power for optimal benefit and system efficiency, including energy and longevity. The “auto” mode may be a default strategy that the vehicle resets to after a power on. Still in another example a power mode option is a “charging” mode. The vehicle operator may select this option from the solar menu so that the system stores maximum electrical energy from solar power in the energy storage device (e.g., the low voltage battery). Another mode is a “climate” mode to provide temperature control to the interior of the vehicle and/or certain vehicle components, (e.g., the high voltage battery).
With reference to
In an example the power mode is a “climate” mode. In the “climate” mode, the vehicle energy management system may use the solar power to ventilate the passenger compartment 11. This is contributes to reducing the effects of radiant heating, such as during a warm day. When the “climate” mode is selected, a vehicle heating, ventilation, and air conditioning (HVAC) system 181 can be engaged to circulate air within the vehicle. The HVAC system 181 conditions a flow of air by heating 186 or cooling 185 the airflow and distribution the flow of conditioned air within the vehicle. In an example, the HVAC system 181 can include an air inlet duct, air inlet opening, blower, evaporator core, heater core, a sensor, a temperature control actuator, and switches that are conventional and known in the art to operatively transfer, condition and distribute the air flow.
Thus, the circulation of air in the “climate” mode reduces the buildup of heat in the vehicle due to radiant heating. For example, stored electrical energy may be utilized to operate an HVAC system 181 fan that circulates air within the interior of the vehicle. The fan may be positioned in an interior of the vehicle, such as within the instrument panel, or within a console, or within a seat or within a body panel or the like. The fan may also be utilized to circulate air when the vehicle is in an “on” mode. In an example, a fan 184 is mounted in a seat of the vehicle and typically the seat frame of the vehicle. Fan 184 can provide the seat occupant with additional conditioned air.
The vehicle operator may select any of these options from an interactive solar menu displayed on a display device 170. Referring to
In an example of display 17, the center of the interface can be composed of a “Dinergy graph” that represents the energy absorbed. This radial graph contains a set number of zones depending on which one of the four graphs the user selects. In an example, these zones are populated by 10 “petals” that stack one under the other from smallest to largest. There are 4 “Dinergy” graphs that represent consumption during the current day, current month, year, and the user's trip for example. The day “Dinergy” graph represents 12 hours of the day (12 zones), the month represents 31 days (31 zones), the year represents 12 months (12 zones), and the trip represents the last 12 hours (12 zones). The graph can work as a stepped scale, meaning there are 10 steps to fill. When the absorption passes a certain amount, the next step can be illuminated to the user. Each successive step can illuminate a larger “petal” underneath the last petal displayed. This addition can continue until the allotted time for the zone runs out and then this cycle continues again in the next zone. In an example, this process can work under three scales: minor absorption, mainstream absorption, and major absorption. Depending on a bi-weekly average of data, the system will choose what scale to display the information. This way, someone who operates the vehicle in a low-sunlight geographical area will have the use of a scale from 1 to 10, just as someone who operates in a high-sunlight area can also have a better use of a scale.
In an upper left quadrant of the display there can be a real time indicator of energy absorbed related to the “Dynergy” graph. A bar graph that displays current real time absorption can be placed in the far left hand corner with a refresh rate calculated based on the mode it is in (Day, Month, Year, trip). The bar graph's scale can be determined by the absorption scale mentioned above. The “Dynergy” graph's mode can also be displayed atop of the bar graph.
In a further example, on the right of the interface are the controls to replace the mode observed and the amount of energy absorbed. The energy absorbed area is found in the upper right quadrant and displays energy absorbed in terms of miles earned as a total since the vehicle is operative and the miles earned based on the current trip. Underneath this information can be the buttons that allow the user to chose the display mode of either Trip, Day, Month, and Year.
In an even further example, there are two animations that can happen simultaneously that communicate the level of absorption of solar energy by the solar cells. The first can be a 5 step illumination of the cells that coincide with a 5 step matrix scale. The scale covers the gamut of no energy absorbed to high amounts of absorption in those 5 steps. The second animation can run after the 3rd scale which shows a highlight running from the front of the car to the rear in a sequential manner. This second animation can reinforce the first in communicating the amount of energy being absorbed.
Referring to
In still another example, the charge indicator 190 is integral with an exterior surface of the vehicle 10, and is illuminated to represent the charge. The illuminated charge indicator 190 is integrally formed in the body of the vehicle 10. In this example, the illuminated charge indicator illustrates the rate of solar charging. The illuminated charge indicator 190 may be formed in a member 191 associated with a outer body panel as shown at 190, such as along a door edge or on a fender or the like. The member 191 may be an external trim member that is illuminated from behind by a plurality of lights 192 arranged and illuminated in a predetermined manner.
In this example, the lights 192 are LED lights arranged in a linear manner, although other patterns may be selected, such as circular or non-linear. The LED lights may be a predetermined color, such as clear or red or green. Further, in this example, the lights may be illuminated in a predetermined manner, such as by color or sequence, in order to indicate the charge status. For example, a pulsing red light indicates that the solar panel is charging the battery, and a solid green light indicates that the battery is fully charged. A combination of lights can be sequentially illuminated to provide notification of the charge state (i.e. none, partially or fully charged). The illuminated trim member may be fabricated from various materials, such as a chrome plated plastic or the like. Preferably, the external trim member is semi-opaque, and is aesthetically pleasing when the vehicle is not in operation, but allows the light to shine through to provide the charge status.
Many modifications and variations of the present disclosure are possible in light of the above teachings. Therefore, within the scope of the appended claim, the present disclosure may be practiced other than as specifically described.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/21269 | 1/15/2010 | WO | 00 | 2/13/2012 |
Number | Date | Country | |
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61144976 | Jan 2009 | US |