Patent Publication Number: US-2022234461-A1

Title: Power distribution system including remotely controllable power receptacle and an electric vehicle mobile charger having an actuatable power connection mechanism

Description:
INTRODUCTION 
     The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     The present disclosure relates to power distribution systems including a remotely controllable power receptacle and an electric vehicle mobile charger having an actuatable power connection mechanism. 
     Power distributions systems for electric vehicles typically include stationary charging stations that are only capable of charging electric vehicles parked nearby the charging stations. For example, the charging stations are typically equipped with a power cord that is used to electrically connect the battery of an electric vehicle with a power source such as an electrical grid. Since the charging stations are stationary, the charging stations are only capable of charging electric vehicles parked within reach of the power cord. Thus, the number of electric vehicles that can be charged by each of the charging stations is limited. 
     SUMMARY 
     An example of a power distribution system according to the present disclosure includes a charging station, a plurality of power socket assemblies, and at least one power line. The charging station includes a charging station control module. The plurality of power socket assemblies are operable to supply power to a vehicle. The at least one power line electrically connects the charging station to each of the plurality of power socket assemblies. The charging station is configured to supply power to any one of the plurality of power socket assemblies through the at least one power line. 
     In one example, the at least one power line includes a single power line that electrically connects the charging station to all of the plurality of power socket assemblies. 
     In one example, the at least one power line includes a first power line and a second power line. The first power line electrically connects the charging station to a first subset of the plurality of power socket assemblies. The second power line electrically connects the charging station to a second subset of the plurality of power socket assemblies. 
     In one example, the at least one power line includes a main power line and a plurality of branch power lines. The main power line electrically connects the charging station to the plurality of branch power lines. Each of the plurality of branch power lines electrically connects the main power line to at least one of the plurality of power socket assemblies. 
     In one example, each of the plurality of power socket assemblies includes a power socket and a switch operable to regulate current flow from the at least one power line to the power socket. 
     In one example, each of the plurality of power socket assemblies further includes a power socket control module configured to open and close the switch in response to a wireless control signal. 
     In one example, each of the plurality of power socket assemblies further includes a socket cover that allows access to the respective socket when the socket cover is open and prevents access to the respective socket when the socket cover is closed, and each of the plurality of power socket assemblies further includes a power socket control module configured to open and close the socket cover in response to a wireless control signal. 
     In one example, the power distribution system further includes a mobile charger. The mobile charger includes a power plug for electrically connecting the vehicle to the power socket of any one of the plurality of power socket assemblies. The mobile charger is operable to move to align the power plug with the power socket. 
     In one example, the mobile charger further includes a base, a plurality of wheels attached to the base, and an electrical connector into which the power plug integrated, and the electrical connector is configured to extend and retract relative to the base to respectively insert the power plug into the power socket of any one of the plurality of power socket assemblies and withdraw the power plug from the power socket. 
     In one example, the mobile charger further includes a mobile charger control module and a contact sensor integrated into the power plug, and the mobile charger control module is configured to determine whether the power plug is inserted into the power socket of any one of the plurality of power socket assemblies based on an input from the contact sensor. 
     In one example, the mobile charger control module is configured to generate a wireless ON code signal when the power plug is inserted into the power socket of any one of the plurality of power socket assemblies and, in response to the wireless ON code signal, the charging station control module is configured to close the switch in the respective one of the plurality of power socket assemblies to supply power to the power socket of the respective one of the plurality of power socket assemblies. 
     In one example, the mobile charger control module is configured to generate a wireless OFF code signal when the power plug is withdrawn from the power socket of any one of the plurality of power socket assemblies and, in response to the wireless OFF code signal, the charging station control module is configured to open the switch in the respective one of the plurality of power socket assemblies to interrupt power supply to the power socket of the respective one of the plurality of power socket assemblies. 
     In one example, the mobile charger further includes a mobile charger control module and an image sensor integrated into the power plug, and the mobile charger control module is configured to determine whether the power plug is aligned with the power socket of any one of the plurality of power socket assemblies based on an input from the image sensor. 
     In one example, the mobile charger further includes a mobile charger control module, an image sensor integrated into the power plug, and an air nozzle, and each of the plurality of power socket assemblies further includes a socket cover operable to open and close to respectively allow and prevent access to the respective socket. In addition, the mobile charger control module is configured to determine whether a substance is disposed on a top surface of the socket cover of any one of the plurality of power sockets assemblies based on an input from the image sensor, and control the air nozzle to spray air toward the socket cover when the substance is disposed on the top surface of the socket cover. 
     In one example, the mobile charger further includes a base, a plurality of wheels attached to the base, and a protection shield coupled to the base, and the protection shield is configured to extend and retract relative to the base to respectively create a seal around the socket cover of any one of the plurality of power socket assemblies and break the seal. 
     An example of a mobile charger according to the present disclosure includes a base, a plurality of wheels, an electric motor, a power plug, and a mobile charger control module. The plurality of wheels are attached to the base. The electric motor is configured to drive at least one of the plurality of wheels. The power plug is coupled to the base and configured to electrically connect a vehicle to a power socket. The mobile charger control module is configured to control the electric motor to move the mobile charger in order to align the power plug with the power socket. 
     In one example, the mobile charger further includes an electrical connector into which the power plug is integrated. The electrical connector is operable to extend from the base and retract into the base to respectively insert the power plug into the power socket and withdraw the power plug from the power socket. 
     In one example, the mobile charger further includes a contact sensor integrated into the power plug. The mobile charger control module is configured to determine whether the power plug is inserted into the power socket based on an input from the contact sensor. 
     An example of a power socket assembly according to the present disclosure includes a power socket, a socket cover, and a power socket control module. The socket cover is operable to open and close. The socket cover allows access to the power socket when the socket cover is open. The socket cover prevents access to the power socket when the socket cover is closed. The power socket control module is configured to open and close the socket cover in response to a wireless control signal. 
     In one example, the power socket assembly further includes an electric motor, a plurality of shutters, and at least one of a gear and a linkage mechanically connecting the electric motor to the plurality of shutters. The plurality of shutters are movable between a first position and a second position. The socket cover is open when the plurality of shutters are in the first position. The socket cover is closed when the plurality of shutters are in the second position. The power socket control module is configured to control the electric motor to move the plurality of shutters between the first position and the second position in response to the wireless control signal. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a functional block diagram illustrating a first example of a power distribution system according to the present disclosure; 
         FIG. 2  is a functional block diagram illustrating a second example of a power distribution system according to the present disclosure; 
         FIG. 3  is a functional block diagram illustrating a third example of a power distribution system according to the present disclosure; 
         FIG. 4  is a section view of an example power socket assembly according to the present disclosure; 
         FIG. 5  is a bottom view of the power socket assembly of  FIG. 4 ; 
         FIG. 6  is a side view of the power socket assembly of  FIG. 4 ; 
         FIG. 7  is a top view of a remotely controllable socket cover included in the power socket assembly of  FIG. 4 ; 
         FIG. 8  is a top view of a second example of a remotely controllable socket cover according to the present disclosure; 
         FIG. 9  is a top view of a third example of a remotely controllable socket cover according to the present disclosure; 
         FIG. 10  is a side view of the remotely controllable socket cover of  FIG. 9 ; 
         FIG. 11  is a side view of an electric vehicle (EV) mobile charger including an actuatable power connection mechanism according to the present disclosure; 
         FIG. 12  is a top view of a portion of the EV mobile charger of  FIG. 11 ; 
         FIG. 13  is a section view of a portion of the EV mobile charger of  FIG. 11  taken along a line  13 - 13  shown in  FIG. 12 ; 
         FIG. 14  is a flowchart illustrating an example method of controlling a power distribution system according to the present disclosure; 
         FIG. 15  is a side view of the EV mobile charger of  FIG. 11  positioned above the power socket assembly of  FIG. 4  with the power connection mechanism in a retracted position; and 
         FIG. 16  is a side view of the EV mobile charger of  FIG. 11  positioned above the power socket assembly of  FIG. 4  with the power connection mechanism in an extended position. 
     
    
    
     In the drawings, reference numbers may be reused to identify similar and/or identical elements. 
     DETAILED DESCRIPTION 
     New power distribution systems have been developed to overcome the shortcomings of a power distribution system including stationary chargers. One such power distribution system includes a stationary charging station controller electrically connected to a power source, a mobile charger electrically connected to the charging station controller, and guide rails along which the mobile charger moves. In one example, the mobile charger is a high-power mobile direct current (DC) charger, and the mobile charger is electrically connected to the charging station controller using a DC fast charging cable. 
     In another example, the mobile charger is electrically connected to the charging station controller using a pair of contact wires placed underground and extending along the guide rails, and a pair of conductor poles extending from the mobile charger to the contact wires. The contact wires are electrically connected to the charging station controller with one of the contact wires forming a supply side of a circuit and the other contact wires forming a return side of the circuit. Each of the conductor poles is in contact with one of the contact wires to complete the circuit. The conductor poles extend through openings in the ground surface that provide access to the contact wires. 
     The mobile charger is equipped with a power chord that electrically connects the mobile charger to the battery of an electric vehicle. Since the mobile charger is able to move along the guide rails, the power distribution system is able to charge an electric vehicle parked in any parking space that is positioned adjacent to the guide rails. In one example, the guide rails extend past several parking spaces, and therefore the power distribution system is capable of charging several electric vehicles without moving the electric vehicles. 
     Despite this benefit, the power distribution system may have some issues. For example, a DC fast charging cable is heavy due to its thick gauge, so therefore it is not practical for the mobile charger to drag such a long and heavy cable as it travels a long distance to charge multiple electric vehicles. In another example, the guide rails for the mobile charger are not flexible in layout and require a high cost to install. In yet another example, it may not be desirable to have the openings through which the conductor poles extend in order to contact the contact wires. 
     A power distribution system according to the present disclosure incorporates various aspects that overcome the issues noted above. In one example, the power distribution system includes a stationary charging station controller, multiple power sockets placed near parking spaces at ground surface and electrically connected to the charging station controller, and a mobile charger. The power sockets are electrically connected to the charging station controller using one or more power lines that are placed underground. The mobile charger is operable to electrically connect the battery of an electric vehicle parked in one of the parking spaces to one of the power sockets disposed near that parking space. In addition, the mobile charger is operable to move autonomously from one power socket to another power socket to charge all electric vehicles parked in the parking spaces without moving the electric vehicles. 
     Since the mobile charger is electrically connected to the charging station controller using stationary power lines and power sockets, there is no need for the mobile charger to drag along a charging cable. Since the mobile charger moves from power socket to power socket autonomously, there is no need for guide rails, which increases the number of possible layouts of the power distribution system and decreases the installation cost thereof. Since the power sockets are placed at ground surface, there is no need for openings in the ground surface such as those described above that provide access to the contact wires. 
     Referring now to  FIG. 1 , a power distribution system  10  includes a charging station  12 , power socket assemblies  14 , a power line  16  electrically connecting the charging station  12  to the power socket assemblies  14 , and a mobile charger  18 . The charging station  12  is configured to supply power to any one of the power socket assemblies  14  through the power line  16 . The power socket assemblies  14  and/or the power line  16  may be placed underground and/or on the surface of the ground. 
     The charging station  12  includes a switch (not shown) and a charging station control module  20  that controls the switch. The switch has an input electrically connected to a power source (not shown) and an output electrically connected to the power line  16 . The power source may be an alternating current (AC) power source or a direct current (DC) power source. The voltage supplied by the power source may be within a range from 120 volts (V) to 500 V. For example, the voltage supplied by the power source may be 120 V AC, 240 V AC, or 480 V DC. 
     The charging station control module  20  closes the switch to electrically connect the power socket assemblies  14  to the power source and thereby supply power to the power socket assemblies  14 . The charging station control module  20  opens the switch to electrically disconnect the power socket assemblies  14  from the power source and thereby interrupt power supply to the power socket assemblies  14 . Although the charging station control module  20  is shown separate from the charging station  12 , the charging station control module  20  may be housed within the charging station  12 . 
     In the example shown in  FIG. 1 , each power socket assembly  14  is disposed at the intersecting point of four parking spaces  22  and is therefore positioned to supply power to an electric vehicle (not shown) parked in any one of the four parking spaces  22 . In other examples, one of the power socket assemblies  14  may be placed at each parking space  22  such that the number of power socket assemblies  14  is equal to the number of parking spaces  22 . Each power socket assembly  14  can be remotely (or wirelessly) turned on and off to start or stop power supply from the power socket assembly  14  to an electric vehicle connected thereto. In one example, the charging station control module  20  generates a wireless control signal to turn on or off any one of the power socket assemblies  14 . In this example, the charging station control module  20  determines which one of the power socket assemblies  14  (if any) the charging station  12  is to supply power. 
     The mobile charger  18  is operable to electrically connect one of the power socket assemblies  14  to an electric vehicle parked in one of the parking spaces  22 . When the mobile charger  18  is positioned above one of the power socket assemblies  14 , the mobile charger  18  may electrically connect that power socket assembly  14  to an electric vehicle parked in one of the parking spaces  22  adjacent thereto. The mobile charger  18  moves autonomously to position itself above one of the power socket assemblies  14 . 
     In one example, the mobile charger  18  generates a wireless ON code signal when the mobile charger  18  is electrically connected to one of the power socket assemblies  14 . The wireless ON code signal indicates an ON code. If the ON code indicated by the wireless ON code signal matches a predetermined ON code, the charging station control module  20  generates the wireless control signal to turn on the power socket assembly  14  to which the mobile charger  18  is connected. In this manner, the charging station control module  20  ensures that the ON code is authentic to ensure that the mobile charger  18  is authorized to supply power from the power socket assembly  14  to an electric vehicle parked adjacent thereto. 
     Conversely, the mobile charger  18  may generate a wireless OFF code signal when the mobile charger  18  is electrically disconnected from one of the power socket assemblies  14 . The wireless OFF code signal indicates an OFF code. If the OFF code indicated by the wireless OFF code signal matches a predetermined OFF code, the charging station control module  20  generates the wireless control signal to turn off the power socket assembly  14  to which the mobile charger  18  is connected. 
     In the example shown in  FIG. 1 , a single power line (i.e., the power line  16 ) electrically connects the charging station  12  to all of the power socket assemblies  14 . In addition, the charging station  12  and the power socket assemblies  14  are disposed in a straight line. In other examples, the charging station  12  may be electrically connected to the power socket assemblies  14  using multiple power lines. Additionally or alternatively, the charging station  12  and the power socket assemblies  14  may be arranged in layouts other than a straight line. 
     Referring now  FIG. 2 , a power distribution system  24  is similar or identical to the power distribution system  10  except that the power line  16  is replaced with a main power line  26  and branch power lines  28 . The main power line  26  electrically connects the charging station  12  to the branch power lines  28 . Each branch power linen  28  electrically connects the main power line  26  to one of the power socket assemblies  14 . 
     The power distribution system  24  also differs from the power distribution system  10  because all of the power socket assemblies  14  are not arranged in a straight line with the charging station  12  or with each other. Instead, one-half of the power socket assemblies  14  are disposed along a first line  30 , and the other half of the power socket assemblies  14  are disposed along a second line  32 . The first line  30  is offset from the main power line  26  in a first direction  34 , and the second line  32  is offset from the main power line  26  in a second direction  36  that is opposite of the first direction  34 . The layout shown in  FIG. 2  may enable the charging station  12  to supply power to more electric vehicles relative to the layout shown in  FIG. 1 . 
     Referring now  FIG. 3 , a power distribution system  38  is similar or identical to the power distribution system  10  except that the power line  16  is replaced with a first power line  40  and a second power line  42 . The first power line  40  extends from a first side of the charging station  12  and electrically connects the charging station  12  to a first subset  44  of the power socket assemblies  14 . The second power line  42  extends from a second side of the charging station  12  opposite of the first side and electrically connects the charging station  12  to a second subset  46  of the power socket assemblies  14 . 
     The power distribution system  38  also differs from the power distribution system  10  because all of the power socket assemblies  14  are not arranged in a straight line with the charging station  12  or with each other. Instead, the first subset  44  of the power socket assemblies  14  are disposed along the first power line  40 , and the second subset  46  of the power socket assemblies  14  are disposed along the second power line  42 . The first and second power lines  40  and  42  are oriented at a non-zero angle (e.g., 90 degrees) relative to one another. The layout shown in  FIG. 3  enables the charging station  12  to supply power to electric vehicles parked in perpendicular rows of the parking spaces  22 . 
     Referring now to  FIGS. 4 through 7 , an example implementation of each power socket assembly  14  includes a power socket  52 , a switch  54 , a socket cover  56 , a socket enclosure  57 , an electric motor  58 , one or more gears  60 , and a power socket control module  62 . The switch  54  includes an input  64  electrically connected to a power line  66  and an output  68  electrically connected to the power socket  52 . The power socket control module  62  closes the switch  54  to supply power from the power line  66  to the power socket  52 . Closing the switch  54  turns on the respective power socket assembly  14 . The power socket control module  62  opens the switch  54  to interrupt power supply from the power line  66  to the power socket  52 . Opening the switch  54  turns off the respective power socket assembly  14 . The power socket control module  62  may open or close the switch  54  in response to the wireless switch control signal generated by the charging station control module  20 . 
     The socket cover  56  is operable to open and close. The socket cover  56  allows access to the power socket  52  when the socket cover  56  is open. The socket cover  56  prevents access to the power socket  52  when the socket cover  56  is closed. The electric motor  58  is operable to open and close the socket cover  56 . The socket enclosure  57  houses the power socket  52 , the switch  54 , the electric motor  58 , and the gears  60 . The power socket control module  62  controls the electric motor  58  to open and close the socket cover  56 . The power socket control module  62  may open and close the socket cover  56  in response to a wireless cover control signal. The power socket control module  62  outputs signals to the switch  54  and the socket cover  56  to control these components. Although the power socket control module  62  is shown separate from the socket enclosure  57  in  FIG. 4 , the socket enclosure  57  may also house the power socket control module  62 . 
     The socket enclosure  57  has a lower end  70 , an upper end  72  opposite of the lower end  70 , and a channel  73  extending through the socket enclosure  57  from the lower end  70  to the upper end  72 . The lower end  70  of the socket enclosure  57  is supported by a base  74 . The power socket  52  is disposed within the channel  73  in the socket enclosure  57 . The socket cover  56  is fitted to the upper end  72  of the socket enclosure  57 . The socket cover  56  covers the channel  73  in the socket enclosure  57  when the socket cover  56  is closed. In the example shown, the base  74  also supports the power line  66  via a pair of pads  76 , which may be made of electrically insulating material. In addition, the power line  66 , the socket enclosure  57 , and the base  74  are disposed beneath a ground surface  78 , and the socket cover  56  is disposed at the ground surface  78 . 
     The gears  60  mechanically connect the electric motor  58  to the socket cover  56 . In the example shown, the gears  60  include a first gear  80  and a second gear  82  that are engaged with one another. The first gear  80  has a first diameter, and the second gear  82  has a second diameter that is greater than the first diameter. The first gear  80  is driven by the electric motor  58  via a shaft  84  that is fixed (e.g., keyed) to the first gear  80  for rotation therewith. The shaft  84  may be considered part of the electric motor  58 . The second gear  82  mechanically connects the first gear  80  to the socket cover  56 . The electric motor  58  opens the socket cover  56  by rotating the shaft  84  and the first gear  80  in a first direction  83 . The electric motor  58  closes the socket cover  56  by rotating the shaft  84  and the first gear  80  in a second direction  85  opposite of the first direction  83 . 
     The socket cover  56  includes a top cover ring  86 , a cover slide subassembly  88 , and connecting pieces  90  linking the cover slide subassembly  88  to the second gear  82 . The connecting pieces  90  may be referred to as linkages. The cover slide subassembly  88  includes spiral-shaped shutters  92  that are moveable in a radial direction between a first position and a second position. The socket cover  56  is open when the shutters  92  are in the first position. The socket cover  56  is closed when the shutters  92  are in the second position as shown in  FIGS. 5 and 7 . Each connecting piece  90  links one of the shutters  92  to the second gear  82 . 
     When the electric motor  58  rotates the shaft  84  and the first gear  80  in the first direction, the first gear  80  rotates the second gear  82  in the second direction. In turn, the second gear  82  moves the shutters  92 , via the connecting pieces  90 , radially outward away from a center  94  of the cover slide subassembly  88  and toward an outer diameter  96  of the cover slide subassembly  88 . When the electric motor  58  rotates the shaft  84  and the first gear  80  in the second direction, the first gear  80  rotates the second gear  82  in the first direction. In turn, the second gear  82  moves the shutters  92 , via the connecting pieces  90 , radially inward away from the outer diameter  96  of the cover slide subassembly  88  and toward the center  94  of the cover slide subassembly  88 . The shutters  92  may move in a spiral manner toward and away from the center  94  of the cover slide assembly  88 . 
     Referring now to  FIG. 8 , a socket cover  100  may be used in place of the socket cover  56 . The socket cover  100  includes rectangular-shaped shutters  102  that are moveable between a first position and a second position. The socket cover  100  is open when the shutters  102  are in the first position. The socket cover  100  is closed when the shutters  102  are in the second position as shown in  FIG. 8 . Each shutter  102  is translated in a first direction  104  to open the socket cover  100 . Each shutter  102  is translated in a second direction  106  opposite the first direction  104  to close the socket cover  100 . 
     As with the socket cover  56 , the socket cover  100  may be open or closed by operating the electric motor  58 . In one example, each connecting piece  90  links one of the shutters  102  to the second gear  82 . In turn, the electric motor  58  moves the shutters  102  in the first and second directions  104  and  106  when the electric motor  58  rotates the first gear  80  in the first and second directions  83  and  85 , respectively. 
     Referring now to  FIGS. 9 and 10 , a socket cover  110  may be used in place of the socket cover  56 . The socket cover  110  includes a pair of semicircular shutters  112  that are moveable between a first position and a second position. The socket cover  110  is open when the shutters  112  are in the first position as shown by the sold line depiction of the shutters  112  in  FIG. 10 . The socket cover  110  is closed when the shutters  112  are in the second position as shown in  FIG. 9  and by the dashed line depiction of the shutters  112  in  FIG. 10 . Each shutter  112  is rotated in a first direction  114  to open the socket cover  110 . Each shutter  112  is rotated in a second direction  116  opposite the first direction  114  to close the socket cover  110 . 
     In the example shown, each shutter  112  defines a ledge  118  that engages the ledge  118  on the other shutter  112  to create a seal therebetween when the socket cover  110  is closed. The ledge  118  of the shutter  112  on the left side of  FIG. 10  faces downward, and the ledge  118  of the shutter  112  on the right side of  FIG. 10  faces upward. Thus, when the socket cover  110  is opened, the shutter  112  on the right side of  FIG. 10  is rotated in the first direction  114  first, and then the shutter  112  on the left side of  FIG. 10  is rotated in the first direction  114 . Conversely, when the socket cover  110  is closed, the shutter  112  on the left side of  FIG. 10  is rotated in the second direction  116  first, and then the shutter  112  on the right side of  FIG. 10  is rotated in the second direction  116 . 
     As with the socket cover  56 , the socket cover  110  may be open or closed by operating the electric motor  58 . In one example, each connecting piece  90  links one of the shutters  112  to the second gear  82 . In turn, the electric motor  58  moves the shutters  112  in the first and second directions  114  and  116  when the electric motor  58  rotates the first gear  80  in the first and second directions  83  and  85 , respectively. 
     Referring now to  FIGS. 11 through 13 , an example implementation of the mobile charger  18  includes a base  120 , wheels  122 , one or more electric motors  124 , an electrical connector  126 , a protection shield assembly  128 , and a pair of air nozzles  130 . The wheels  122  are attached to the base  120  in a manner that allows the wheels  122  to rotate. The electric motor(s)  124  is/are connected to at least one of the wheels  122  and is/are operable to drive the wheel(s) to which electric motor(s)  124  is/are connected. In one example, each wheel  122  is independently driven by one electric motor  124  such that the mobile charger  18  can be moved forward and backward and steered left or right simply by operating the electric motors  124 . In another example, the mobile charger  18  may include a steering mechanism (not shown) that is connected to at least two of the wheels  122  and is operable to steer the mobile charger  18  left or right. 
     The electrical connector  126  is configured to electrically connect the battery of an electric vehicle to the power socket  52  of any one of the power socket assemblies  14 . The electrical connector  126  has an upper end  132  and a lower end  134  opposite of the upper end  132 . The electrical connector  126  includes a power plug  136  integrated into the lower end  134  thereof. The upper end  132  of the electrical connector  126  may be manually connected to the battery of an electric vehicle using a power cord. Alternatively, the mobile charger  18  may include a robot (not shown) operable to automatically connect the upper end  132  of the electrical connector  126  to the battery of an electric vehicle using a power cord. 
     The electrical connector  126  is operable to extend from the base  120  in a first direction  138  to insert the power plug  136  into the power socket  52  of any one of the power socket assemblies  14  when the electrical connector  126  is positioned above the power socket  52 . The electrical connector  126  is operable to retract into the base  120  in a second direction  140  opposite of the first direction  138  to withdraw the power plug  136  from the power socket  52 . The mobile charger  18  may include a linear actuator (not shown) operable to translate the electrical connector  126  and the first and second directions  138  and  140 . 
     The electrical connector  126  further includes a camera or image sensor  142  integrated into the power plug  136  and a contact sensor  144  integrated into the power plug  136 . The image sensor  142  is configured to capture digital images of objects disposed below the electrical connector  126  and to output a signal indicating the captured images. The contact sensor  144  is configured to detect when the power plug  136  is in contact with another object, such as the power socket  52  of any one of the power socket assemblies  14 , and to output a signal indicating the same. 
     The protection shield assembly  128  includes a protection shield  146  and a hollow shaft  148  that is fixed to or integrally formed with the protection shield  146 . The electrical connector  126  is translatable in the first and second directions  138  and  140  through the hollow shaft  148 . The protection shield  146  has a cylindrical shape with an upper end  150  and a lower end  152  opposite of the upper end  150 . The protection shield assembly  128  further includes an annular seal  154  disposed around the lower end  152  of the protection shield  146 . The annular seal  154  is configured to seat against the outer perimeter of the socket cover  56 , or a portion of the socket enclosure  57  surrounding the socket cover  56 , to form a seal therewith. The annular seal  154  may be made from rubber. 
     The protection shield assembly  128  is operable to extend from the base  120  in the first direction  138  to create a seal with the outer perimeter of the socket cover  56  of any one of the power socket assemblies  14  or a portion of the socket enclosure  57  surrounding the socket cover  56 . The protection shield assembly  128  is operable to retract into the base  120  in the second direction  140  to break the seal. The mobile charger  18  may include a linear actuator (not shown) operable to translate the protection shield assembly  128  and the first and second directions  138  and  140 . 
     In the example shown, the protection shield  146  defines a pair of air channels  156 . Each air channel  156  is in fluid communication with one of the air nozzles  130  to allow the air nozzle  130  to spray air through the protection shield  146  via the air channel  156 . The air sprayed by the air nozzles  130  may be supplied by an air compressor (not shown), which may be onboard (or part of) the mobile charger  18 . The air nozzles  130  are operable to spay air toward the socket cover  56  of any one of the power socket assemblies  14  to remove moisture or debris from the socket cover  56 . An air hose may be integrated into each air nozzle  130  or connected thereto. The protection shield  146  may also define a connector channel that allows the electrical connector  126  to slide through the protection shield  146  via the connector channel to connect the power plug  136  to the power socket  52  or disconnect the power plug  136  from the power socket  52 . Alternatively, the hollow shaft  148  may extend to the lower end  152  of the protection shield  146 . 
     The protection shield assembly  128  further includes a seal sensor  158  integrated into the lower end  152  of the protection shield  146 . The seal sensor  158  is configured to detect whether the protection shield  146  has formed a seal with the socket cover  56  of any one of the power socket assemblies  14  or with a portion of the socket enclosure  57  surrounding the socket cover  56 . The contact sensor  144  and/or the seal sensor  158  may be a proximity sensor. 
     The example implementation of the mobile charger  18  shown in  FIG. 11 through 13  further includes a mobile charger control module  160 . The mobile charger control module  160  is configured to control the electric motor  124  to move the mobile charger  18  in order to align the power plug  136  with the power socket  52  of any one of the power socket assemblies  14 . In addition, the mobile charger control module  160  is configured to control the electrical connector  126 , or a linear actuator connected thereto, to extend and retract the electrical connector  126  in the first and second directions  138  and  140 . Furthermore, the mobile charger control module  160  is configured to control the protection shield assembly  128 , or a linear actuator connected thereto, to extend and retract the protection shield assembly  128  in the first and second directions  138  and  140 . Moreover, the mobile charger control module  160  is configured to control the air nozzles  130  to spray air toward the socket cover  56  of one of the power socket assemblies  14  above which the mobile charger  18  is disposed. The mobile charger control module  160  outputs signals to the electric motor  124 , the electrical connector  126 , the protection shield assembly  128 , and the air nozzles  130  to control the same. 
     The mobile charger control module  160  may output the wireless cover control signal in response to which the power socket control module  62  opens and closes the socket cover  56  of the respective power socket assembly  14 . Alternatively, the charging station control module  20  may output the wireless cover control signal. Each of the modules  20 ,  62 ,  160  may include a transceiver for wirelessly communicating with one another. 
     Referring now to  FIGS. 14 through 16 , an example method for controlling any one of the power distribution systems  10 ,  24 ,  38  begins at  162 . The method is described in the context of the modules  20 ,  62 ,  160 . However, the particular modules that perform the steps of the methods may be different than the modules mentioned in the above descriptions of the methods. Additionally or alternatively, one or more steps of the methods may be implemented apart from the modules  20 ,  62 ,  160 . 
     At  164 , the charging station control module  20  selects an electric vehicle to charge from any electric vehicle parked in the parking spaces  22 . The charging station control module  20  may make the selection based on the order in which electric vehicles parked in the parking spaces  22  and/or the proximity of the electric vehicles to the mobile charger  18 . For example, the charging station control module  20  may charge the electric vehicles in the same order in which the electric vehicles parked in the parking spaces  22 . In another example, the charging station control module  20  may charge the electric vehicle that is closest to the mobile charger  18  and has not yet been charged. The charging station control module  20  may determine when the electric vehicles are parked in the parking spaces  22  and/or the proximity of the electric vehicles to the mobile charger  18  using proximity sensors positioned in or near the parking spaces  22 . The charging station control module  20  outputs a wireless signal indicating the selected electric vehicle. 
     At  166 , the mobile charger control module  160  moves the mobile charger  18  to position the mobile charger  18  above one of the power socket assemblies  14  that is near (e.g., closest to) the selected electric vehicle. In addition, the mobile charger control module  160  moves the mobile charger  18  to align the power plug  136  with the center  94  of the socket cover  56  of the power socket assembly  14  as shown in  FIG. 15 . The mobile charger control module  160  may perform each of these tasks based on an input from the image sensor  142  and/or using predetermined position coordinates (e.g., a global positioning system (GPS) coordinates). 
     At  168 , the mobile charger control module  160  determines whether the power plug  136  is aligned with the center  94  of the socket cover  56 . If the power plug  136  is aligned with the center  94  of the socket cover  56 , the method continues at  170 . Otherwise, the method remains at  166 . 
     At  170 , the mobile charger control module  160  determines whether moisture (e.g., snow, water) or debris (e.g., stones, dirt) is on the top surface of the socket cover  56  based on the input from the image sensor  142 . If moisture or debris is on the top surface of the socket cover  56 , the method continues at  172  before continuing to  174 . Otherwise, the method continues directly to  174 . At  172 , the mobile charger control module  160  controls the air nozzle  130  to spray air at the top surface of the socket cover  56  to clear the moisture or debris therefrom. The method then returns to  170 . At  174 , the mobile charger control module  160  lowers the protection shield assembly  128  toward the socket cover  56 . The mobile charger control module  160  may maintain the electrical connector  126  in its retracted position shown in  FIG. 15  while lowering the protection shield assembly  128 . 
     At  176 , the mobile charger control module  160  determines whether the protection shield  146  is in contact with and sealed to the socket cover  56  as shown in  FIG. 16 . The mobile charger control module  160  may make this determination based on an input from the contact sensor  144 . If the protection shield  146  is in contact with and sealed to the socket cover  56 , the method continues at  178 . Otherwise, the method remains at  174 . At  178 , the charging station control module  20  or the mobile charger control module  160  generates the wireless cover control signal, and the power socket control module  62  opens the socket cover  56  in response to the wireless cover control signal. At  180 , the mobile charger control module  160  lowers the electrical connector  126  to insert the power plug  136  into the power socket  52  as shown in  FIG. 16 . In turn, the electrical connector  126  moves downward relative to both the base  120  and the protection shield assembly  128 . 
     At  182 , the mobile charger control module  160  determines whether the power plug  136  inserts securely into the power socket  52 . If the power plug  136  inserts securely into the power socket  52 , the method continues at  184 . Otherwise, the method continues at  186 . At  184 , the mobile charger control module  160  generates the wireless ON code signal. At  186 , the mobile charger control module  160  sends an alarm to an operator by, for example, transmitting a wireless signal to a cloud computing network or a user interface device. 
     At  188 , the charging station control module  20  determines whether the ON code indicated by the wireless ON code signal is authentic. For example, the charging station control module  20  may determine whether the ON code indicated by the wireless ON code signal matches the predetermined ON code. If the ON code indicated by the wireless ON code signal is authentic, the method continues at  190 . Otherwise, the method continues at  186 . 
     At  190 , the charging station control module  20  generates the wireless switch control signal to turn on the power socket  52 , and the power socket control module  62  closes the switch  54  in response to the wireless switch control signal. At  192 , the mobile charger  18  connects the power plug  136  to the battery of the electric vehicle by, for example, connecting one end of a power cord to the upper end  132  of the electrical connector  126  and the other end of the power cord to the battery. In turn, the battery begins charging. 
     At  194 , the charging station control module  20  determines whether the charging is complete. The charging station control module  20  may determine that charging is complete when a predetermined period has elapsed after the power socket  52  is turned on and/or the power plug  136  is connected to the battery of the electric vehicle. Alternatively, the charging station control module  20  may determine whether charging is complete based on a wireless signal generated by the electric vehicle indicating the charge status of the battery of the electric vehicle. If charging is complete, the method continues at  196 . Otherwise, the method remains at  194 . 
     At  196 , the mobile charger  18  disconnects the power plug  136  from the battery of the electric vehicle by, for example, disconnecting the power cord from the upper end  132  of the electrical connector  126  and/or disconnecting the power cord from the battery. At  200 , the mobile charger control module  160  determines whether the power plug  136  withdraws from the power socket  52 . If the power plug  136  does withdraw from the power socket  52 , the method continues at  202 . Otherwise, the method continues at  186 . At  202 , the mobile charger control module  160  generates the wireless OFF code signal. 
     At  204 , the charging station control module  20  determines whether the OFF code indicated by the wireless OFF code signal is authentic. For example, the charging station control module  20  may determine whether the OFF code indicated by the wireless OFF code signal matches the predetermined OFF code. If the OFF code indicated by the wireless OFF code signal is authentic, the method continues at  206 . Otherwise, the method continues at  186 . 
     At  206 , the charging station control module  20  generates the wireless switch control signal to turn off the power socket  52 , and the power socket control module  62  opens the switch  54  in response to the wireless switch control signal. At  208 , the charging station control module  20  or the mobile charger control module  160  generates the wireless cover control signal, and the power socket control module  62  closes the socket cover  56  in response to the wireless cover control signal. At  210 , the mobile charger control module  160  raises the protection shield assembly  128  away from the socket cover  56 . The mobile charger control module  160  maintains the electrical connector  126  in its retracted position shown in  FIG. 15  while lowering the protection shield assembly  128 . The method ends at  212 . 
     The method of  FIG. 14  may be repeated each time that an electric vehicle is parked in one of the parking spaces  22 . Additionally or alternatively, the method of  FIG. 14  may be repeated on a periodic basis. If there are no electric vehicles parked in the parking spaces  22  that have not yet been charged, then the charging station control module  20  may not select any electric vehicles to charge at  164 , in which case the method may continue from  164  to  212 . 
     The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure. 
     Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” 
     In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A. 
     In this application, including the definitions below, the term “module” or the term “controller” may be replaced with the term “circuit.” The term “module” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip. 
     The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may allow load balancing. In a further example, a server (also known as remote, or cloud) module may accomplish some functionality on behalf of a client module. 
     The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules. 
     The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc). 
     The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer. 
     The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc. 
     The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.