Patent Publication Number: US-2021188105-A1

Title: Self-contained renewable inductive battery charger

Description:
FIELD OF THE INVENTION 
     The present invention pertains generally to charging stations for electric vehicles. More particularly, the present invention pertains to transportable charging stations that incorporate a source of renewable energy which includes both a solar array and a wind turbine. The present invention is particularly, but not exclusively, useful as a transportable charging station that stores electricity from its source of renewable energy for use in establishing a resonant inductive coupling between a primary coil at the charging station and a secondary coil on the electric vehicle for recharging the electric vehicle. 
     BACKGROUND OF THE INVENTION 
     Inductive coupling is an electrical phenomenon which is known to have many practical applications. As a phenomenon, inductive coupling occurs whenever a change in current through a first wire induces a voltage across the ends of a second wire. In order to establish inductive coupling, it is necessary to position a portion of the first wire (i.e. a primary coil) in near proximity to a portion of the second wire (i.e. a secondary coil). 
     In order to use inductive coupling for the specific task of recharging the battery of an electric vehicle, it is necessary to position a secondary coil on the vehicle. It is also necessary to connect the primary coil to a source of electric energy. Heretofore, inductive coupling has been somewhat limited to applications having relatively low power requirements. Thus, primarily due to the relatively high-power requirements for charging the battery of an electric vehicle (e.g. preferably &gt;3 kw), it has been necessary to use a permanently installed source of electric energy, having a substantial power capability (e.g. the “grid”). 
     With the above in mind, there is a demonstrable need for electric vehicle charging stations at locations where, for any of several different reasons, access to the grid is impractical. Also, the present invention appreciates that renewable energy technologies can be transported to local or remote, off-grid locations where they can be effectively operated as self-contained units. 
     For the reasons set forth above, it is an object of the present invention to provide a transportable unit having a self-contained battery charger for charging electric vehicles. Another object of the present invention is to provide a transportable battery charger having a primary induction coil which establishes a resonant inductive coupling with a secondary induction coil on an electric vehicle for recharging the battery of the electric vehicle. Yet another object of the present invention is to provide a transportable charging station that includes a source of renewable energy for charging the primary induction coil of an inductive coupling circuit, wherein the source of renewable energy includes a solar array and/or a wind turbine. Still another object of the present invention is to provide a transportable battery charger for inductively charging an electric vehicle which is simple to manufacture, is easy to use, and is comparatively cost effective. 
     SUMMARY OF THE INVENTION 
     A transportable unit for charging the battery of an electric vehicle includes a moveable docking pad with an access ramp for parking electric vehicles on the docking pad. Also included is a source of renewable energy that is incorporated for transport with the unit. A primary induction coil is affixed to the docking pad, and electric circuitry is provided on the unit for connecting the primary induction coil with the source of renewable energy. A secondary induction coil is positioned on an electric vehicle so that, when the electric vehicle is parked on the docking pad, a resonant inductive coupling is established for recharging the battery of the electric vehicle. 
     For purposes of the present invention, the source of renewable energy will typically include a solar array and/or a wind turbine. This source of renewable energy is directly connected with a storage battery which is located on the transportable unit. Thus, the storage battery receives electricity that is generated both by the solar array, and by the wind turbine. In sequence, an inverter is connected to the storage battery, for converting a d.c. current from the storage battery into an a.c. current that can be used for an operation of the primary induction coil. 
     Also included in the electric circuitry of the present invention is a current control unit. Specifically, the current control unit is located with the circuitry, between the inverter and the primary induction coil. Important functions of the current control unit are to establish the frequency of the a.c. current that is delivered to the primary induction coil, and to regulate the power level of this current. As intended for the present invention, the power level for recharging an electric vehicle will be greater than 3 kw. The current control unit can also function as an ON/OFF switch for the primary induction coil. 
     For an operation of the present invention, a column is provided as part of the transportable unit, and this column includes a platform for supporting the source of renewable energy. In this combination, the column is used to selectively position the source of renewable energy by reconfiguring the column between a collapsed configuration for transportation of the source of renewable energy, and a vertical orientation wherein the source of renewable energy is operable for generating electric energy. It is an important feature of the present invention that, when the column is in its vertical orientation, the source of renewable energy is positioned at a predetermined distance above the docking pad. The purpose here is two-fold. For one, this predetermined distance must allow for the parking of a vehicle on the docking pad. For another, the vertical orientation provides for a safe operational position of the source of renewable energy that minimizes the footprint of the transportable unit. 
     Additional features of the transportable unit include a motor for rotating the solar panel in accordance with a predetermined protocol. Specifically, this protocol is intended to optimize an incidence of sunlight on the solar panel. Further, the transportable unit preferably includes a support structure that is secured to the platform for holding and maintaining the wind turbine in a down-sun position relative to the solar panel. It is envisioned that this support structure will also distance the wind turbine from the solar panel, and thereby avoid interference from the solar panel with the wind that is driving the wind turbine or shading of the solar panel(s) by the wind turbine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
         FIG. 1  is a perspective view of the transportable unit for charging an electric vehicle in accordance with the present invention; and 
         FIG. 2  is a schematic presentation of the electronic circuitry required for operation the transportable unit of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to  FIG. 1 , a transportable unit in accordance with the present invention is shown and is generally designated  10 . As shown, the unit  10  includes a moveable docking pad  12 , with a column  14  that is mounted on the docking pad  12 . It is also shown that the unit  10  includes a solar array  16  and a wind turbine  18 . Together, the solar array  16  and the wind turbine  18  constitute a source of renewable energy  20  (see  FIG. 2 ) for use by the transportable unit  10 . It is also an important aspect of the present invention that the wind turbine  18  is held in a down-sun position, relative to the solar array  16 , so that the solar array  16  does not interfere with the wind turbine  18 , and vice versa. 
       FIG. 1  also shows that a storage battery  22  is positioned on the docking pad  12 . Further,  FIG. 1  shows that a platform  24  for holding the source of renewable energy  20  is mounted on the column  14 . Also, a support structure  26  is provided with the platform  24  for supporting the wind turbine  18  on the support structure  26 . It is also shown in  FIG. 1  that a motor  28  is positioned on the column  14  for rotating the platform  24 , along with the source of renewable energy  20 , through a horizontal arc. As will be appreciated by the skilled artisan, the rotational velocity for position and orientation of the platform  24  will depend on the incidence angle of sunlight on the solar array  16 . Thus, the inclination of the solar array  16  will also be dependent on both the time of day and the latitude of the transportable unit  10 . 
     Still referring to  FIG. 1 , an electric vehicle  30  is shown positioned on the docking pad  12  of the transportable unit  10 . As shown, the electric vehicle  30  is positioned for a recharging operation in accordance with the present invention, the control of a recharging operation will be provided by a charging station  32 , which is incorporated into the transportable unit  10 . 
     With the structure for a transportable unit  10  as disclosed above, it is an important feature of the present invention that the transportable unit  10  be reconfigurable between an operational configuration (i.e.  FIG. 1 ), and a configuration that is convenient for transport. For this purpose, the transition between operational and transport configuration is preferably accomplished in a manner similar to that disclosed in U.S. Pat. No. 9,917,471 which issued to Wheatley, and which is assigned to the same assignee as the present invention. 
     For an operation of the present invention, the schematic presentation of  FIG. 2  is provided for showing the electrical components that interact with each other for the purpose of recharging the electric vehicle  30 . As shown, these components include a primary induction coil  34  which is positioned on the docking pad  12  of the transportable unit  10 , and a secondary induction coil  36  which is installed on the electric vehicle  30 . Thus, when the electric vehicle  30  is driven onto the docking pad  12 , and is parked as shown in  FIG. 1 , the secondary induction coil  36  on the electric vehicle  30  is properly positioned relative to the primary induction coil  34  on the docking pad  12 . Specifically, with the electric vehicle  30  positioned as shown, a resonant inductive coupling  38  can be established between the primary induction coil  34  and the secondary induction coil  36  for recharging the electric vehicle  30 . 
     As intended for the present invention, the resonant inductive coupling  38  is established via an electromagnetic field which is generated by the primary induction coil  34  with an a.c. electric current from the storage battery  22 . In detail, an inverter  40  is provided to convert a d.c. current from the storage battery  22  into the a.c. current. Further, a current control  42  is electrically connected with the inverter  40 , to establish a frequency and a current level for the a.c. current. The a.c. current then drives the primary induction coil  34  to generate an alternating electromagnetic field. 
     For purposes of the present invention, the alternating electromagnetic field that is generated by the primary induction coil  34  will have a predetermined power level that is capable of recharging a battery  44  of the electric vehicle  30 . Preferably, the power level for charging the battery  44  will be greater than 3 kw.  FIG. 2  also shows that an indicator  46  can be installed with the electric vehicle  30  for the purpose of displaying the charging status of the battery  44  during a recharging operation. 
     While the particular Self-Contained Renewable Inductive Battery Charger as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.