Abstract:
A system and method for electrically charging a plurality of electric vehicles is operated continuously to charge the vehicles in repetitive cycles from a same power source. During the time of a charging cycle, T cycle , (i.e. the sequence time needed to incrementally charge all vehicles connected to the power source), each vehicle is connected to the power source, in turn, for a same time duration, t d . When completed, each cycle is then repeated. As vehicles are either connected or disconnected from the power source, the total time of the charging cycle, T cycle , is respectively extended or shortened by t d . Operationally, although T cycle  will vary as vehicles come and go, t d  remains constant.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to systems and methods for charging a plurality of electric vehicles from a same power source. More particularly, the present invention pertains to systems and methods for sequentially charging electric vehicles during successive charging cycles. The present invention is particularly, but not exclusively, useful as a system or method for providing an n number of charging stalls to sequentially charge an N number of vehicles during a charging cycle, when N is less than or equal to n. 
       BACKGROUND OF THE INVENTION 
       [0002]    Along with an increasing interest in the use of electricity for generating vehicular motive power, a consequent interest concerns how to provide the electrical power for this purpose. As is well known and appreciated, the task of electrically charging a vehicle takes time (e.g. several hours). Further, the actual time that is needed to efficiently charge a vehicle is dependent on several factors, such as power level and charging point availability. Moreover, the industry has now progressed to the point where operational and structural standards have been established for manufacturing components for use at a charging station. With all this in mind, the issue becomes how best to achieve maximum charging efficiency, within existing industry requirements, for as many electric vehicles as possible. 
         [0003]    Range anxiety and charger availability are some of the biggest concerns for electric vehicle (EV) drivers. More abundant and available charging infrastructure is the best way to combat these concerns, but installing new complete stations can be expensive and difficult due to electrical grid or power supply limitations, installation costs, and permitting. Additionally, each EV charging station (EVCS) can only supply a finite amount of power through one, or at most, two standard outlets with current designs. Coupled with extended charge times, this means EVCS installations can quickly become unavailable in frequented charging areas. 
         [0004]    SAE J1772 is an international standard that defines the physical design, communications protocol, and power requirements of the charging interface and controllers within an EV and an EVCS. The standard connector is called a coupler on the EVCS side and an inlet on the EV side. There are 5 electrical pins within each coupler: 2 power, 1 ground, and 2 control pins called a pilot and proximity. The pilot pin is the primary control connection that passes the required communication signal to enable, initialize, and monitor charging between an EV and an EVCS. The proximity pin is part of a separate control circuit within a coupler and an EV that informs the EV when a coupler is being connected or removed. Power requirements fall within two categories under the standard. Level 1 charging uses a 120 volt (V) alternating current (AC) circuit while Level 2 charging requires a 240V AC circuit. Both power levels can be supplied over the same coupler design and all existing Level 1 and Level 2 stations must follow this standard. 
         [0005]    SAE J1772 also defines a standard combination coupler with extra pins to pass direct current (DC) at increased Level 1 and Level 2 rates. The DC charging sequence is controlled and monitored by a similar proximity and pilot methodology as the AC standard. CHAdeMO is a third standard for DC charging at high rates. The coupler and communications protocol are different from the SAE J1772 standard, but the overall process is similar. 
         [0006]    With the above in mind, it is an object of the present invention to provide a system and method for increasing the available charging infrastructure for electric vehicles by adapting existing charging stations with a multi-coupler expansion adapter that will simultaneously accommodate a plurality of electric vehicles. Another object of the present invention is to provide a multi-coupler adapter for use with a single power source which sequentially charges a plurality of electric vehicles. Yet another object of the present invention is to provide a multi-coupler expansion adapter that is simple to use, is relatively easy to manufacture, and is comparatively cost effective. 
       SUMMARY OF THE INVENTION 
       [0007]    In accordance with the present invention, a multi-coupler expansion adapter is provided which will increase the available charging infrastructure for electric vehicles using the same charging station. Specifically, this is done by adapting existing charging stations so they can simultaneously accommodate a plurality of electric vehicles. In their combination, components of the present invention incorporate the multi-coupler expansion adapter to interconnect a single power source with a variable plurality of different electric vehicles (e.g. 6 or 8 vehicles). 
         [0008]    For the methodology of the present invention, a time duration, t d , is established during which each electric vehicle is individually charged. In this scheme, t d  remains constant and it is the same for each vehicle. Charging the plurality of vehicles that is connected into the system is then conducted continuously in a sequence of time durations, t d . The sum total, Σt d , results in an uninterrupted charging time cycle, T cycle . According to the present invention, as the number of vehicles in the plurality is increased, or decreased, T cycle  will respectively increase or decrease by the increment/decrement t d . 
         [0009]    Components for the multi-coupler adapter of the present invention include, in combination, a controller, a sensor and a timer. In this combination, the controller is used for individually connecting a power source to each electric vehicle in the plurality of the electric vehicles. More specifically, as intended for the present invention, the controller gives the adapter a capability for individually connecting with an n number of different electric vehicles. For this capability, the sensor is used for identifying the N number of vehicles that are actually connected with the controller, at any one time. Thus, although N will fluctuate depending on the number of vehicles being charged, N will always be less than n+1. The timer that is included in the multi-coupler adapter is used for actuating the controller to sequence individual connections of time duration t d , between the power source and the N number of electric vehicles. 
         [0010]    With the above in mind, several important aspects of the invention deserve consideration. For one, T cycle =Nt d =Σt d , and t d  will preferably be equal to approximately ten minutes. Further, as indicated above, N will fluctuate. Therefore, N will need to be reset with a decrement 1 whenever an electric vehicle has been charged and removed from the system. N will also need to reset with an increment 1 whenever an electric vehicle is initially connected into the system. 
         [0011]    In accordance with regulatory requirements, the multi-coupler adapter will include a first power pin for providing power from the power source to charge the electric vehicle at a level 1 rate. The multi-coupler adapter will also include a second power pin for providing power from the power source to charge the electric vehicle at a level 2 rate. As envisioned for the present invention, charging at either of these rates will be accomplished in response to an operation of the controller. Further, the power level that is provided by the power source for charging an electric vehicle may be 120 volts alternating current (120V AC), 240 volts alternating current (240V AC) or a direct current voltage. 
         [0012]    With the above in mind, a method for sequentially charging a plurality of electric vehicles in accordance with the present invention requires first setting up the system. In essence, this involves providing a power source which has been adapted to service an n number of charging stalls. Further, each of the charging stalls is configured to establish an appropriate individual power connection between the power source and the electric vehicle that is using the stall. In particular, this adaptation is accomplished by the multi-coupler adapter of the present invention. 
         [0013]    Once the power source has been prepared for operation, the methodology of the present invention requires identifying the N number of vehicles that are actually connected with the controller of the multi-coupler adapter. Recall, N will be less than n+1. With N established, a sequence of connections is actuated between the power source and the N number of electric vehicles. In detail, this sequence extends during the time of an uninterrupted sequence cycle, T cycle , and it is continuously repeated. Importantly, during each T cycle , each electric vehicle is connected with the power source for a same time duration t d . 
         [0014]    As a sequence of cycles is repeated, it is anticipated that N will fluctuate. If so, N will be reset with a decrement 1 when an electric vehicle has been charged and removed from the system, and it will be reset with an increment 1 whenever an electric vehicle is initially connected into the system. Moreover, empty stalls in the sequence cycle will simply be bypassed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    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: 
           [0016]      FIG. 1  is a perspective view of a multi-vehicle charging station in accordance with the present invention; 
           [0017]      FIG. 2  is a schematic of the operational components for a multi-coupler adapter in accordance with the present invention; 
           [0018]      FIG. 3  is functional schematic of the multi-coupler adapter for use at a multi-vehicle charging station; 
           [0019]      FIG. 4  is time diagram for the implementation of an uninterrupted charging sequence for the system of the present invention; and 
           [0020]      FIG. 5  is a logic flow chart for task completion during an operation of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Referring initially to  FIG. 1 , a system for charging a plurality of electric vehicles in accordance with the present invention is shown, and is generally designated  10 . As shown, the system  10  includes an adapter  12  that has the capability of interconnecting a single power source  14  with a plurality of different couplers  16 . In turn, each coupler  16  in the plurality is capable of individually connecting the power source  14  with an electric vehicle  18 . 
         [0022]    In general, the system  10  will be capable of charging an n number of vehicles  18  during a defined time cycle, T cycle . Typically, n will be six or eight. For disclosure purposes, however, the system  10  that is shown in  FIG. 1  is considered as having the capability of servicing six different vehicles  18  (e.g. n=6). Accordingly, the system  10  will have six stalls that are hereinafter individually referenced by corresponding letters a-f. Using these notations, the coupler  16  for the “b” stall is hereinafter referred to as coupler  16   b . Similarly, the electric vehicle  18  that occupies the “a” stall is hereinafter referred to as electric vehicle  18   a . With this in mind, and as shown in  FIG. 1 , the system  10  is shown charging electric vehicles  18   a ,  18   d  and  18   f , which are respectively connected with couplers  16   a ,  16   d  and  16   f . The couplers  16   a ,  16   d  and  16   f , however, are not shown in  FIG. 1  because they are respectively coupled to the electric vehicles  18   a ,  18   d  and  18   f . On the other hand, couplers  16   b ,  16   c  and  16   e  are shown because they are “not in use” (i.e. the couplers  16   b ,  16   c  and  16   e  are in vacant stalls “b”, “c” and “e”). 
         [0023]    A schematic of the operational components for a multi-coupler adapter  12  of the present invention is shown in  FIG. 2 . As emphasized in  FIG. 2 , the adapter  12  interconnects a single power source  14  with a plurality of individual couplers  16  (e.g. couplers  16   a - f ). As envisioned for the system  10 , the power source  14  will be capable of providing power at 120 volts alternating current (120V AC), 240 volts alternating current (240V AC) and/or with direct current voltage (DC). 
         [0024]    In detail,  FIG. 3  shows that the adapter  12  includes, in combination, a power unit  20 , a control unit  22  and a sensor  24 . Further, the control unit  22  is shown to include a timer  26  and a controller  28 .  FIG. 3  also shows that the adapter  12  is joined to a connecting cable  30  which incorporates individual connecting lines  32   a - f  that each terminate at a respective plurality of couplers  16   a - f.    
         [0025]    Still referring to  FIG. 3 , it is to be appreciated that a multi-coupler adapter  12  in accordance with the present invention incorporates the five different pin connections that are needed to comply with regulatory requirements. These are: a first power pin  34 , a second power pin  36 , a ground pin  38 , a pilot pin (not shown) for the control unit  22 , and a proximity pin (not shown) for the sensor  24 . Within this scheme, the first power pin  34  and the second power pin  36  can be established to provide the power levels noted above for charging the vehicles  18  (i.e. 120V AC, 240V AC, and DC). 
         [0026]    Structurally, the controller  28  of the system  10  is used for individually connecting the power source  14  with each electric vehicle  18  in the plurality of possible electric vehicles  18   a - f . As intended for the present invention, the adapter  12  has the capability for individually connecting with all of the n number of different electric vehicles  18  in the n different stalls (i.e. a-f), at the same time. As envisioned for the present invention, however, there will be times when some of the stalls a-f will be vacant. For this eventuality, the sensor  24  is provided to identify the N number of vehicles  18  that are actually connected with the controller  28  at any particular time. Thus, at any given time, N may be less than n, or it may be equal to N (i.e. 0&lt;N≦n). Stated differently, however, N is always an integer less than n+1. 
         [0027]    Within the adapter  12 , the timer  26  is used to actuate the controller  28 , and to thereby sequence connections between the power source  14  and the N number of electric vehicles  18 . For the present invention, this sequencing is accomplished during the time of an uninterrupted sequence cycle, T cycle . During this sequence cycle, T cycle , each electric vehicle  18  is connected with the power source  14  for a same time duration t d . 
         [0028]    Referring now to  FIG. 4 , a full capacity time cycle, T cycle , is shown and is generally designated  40 . As shown the full capacity time cycle T cycle    40  can accommodate all n (e.g. n=6) vehicles  18   a - f , at the same time. Accordingly, in an uninterrupted sequence, T cycle    40  will include all n number of time durations t d , with only one time duration t d  being provided for each of the vehicles  18   a - f . Note: for T cycle    40 , only the time durations t d(a)  and t d(c)  have been respectively identified for stalls “a” and “c”. 
         [0029]    With reference to the example presented above for vehicles  18   a ,  18   d , and  18   f , N=3. Further,  FIG. 4  indicates that only respective time durations t d(a) , t d(d) , and t d(f)  are assigned to the exemplary time cycle T cycle    41 . Importantly, t d(b ), t d(c) , and t d(e)  have been bypassed and are not been included because the “b”, “c” and “e” stalls are vacant (empty). During this exemplary time cycle T cycle    41 , the following conditions are recognized:
       N=3 to establish T cycle =3t d ;   Sensor  24  identifies that electric vehicle  18   a  in stall “a” is connected to system  10 ;   Controller  28  connects with electric vehicle  18   a  via connecting line  32   a;      Electric vehicle  18   a  is charged from power source  14  for a time duration t d(a) , represented by the dashed line  42 ;   Advance, in sequence, to the next occupied stall (i.e. stall “d”);   Sensor  24  identifies that electric vehicle  18   d  in stall “d” is connected to system  10 ;   Controller  28  connects with electric vehicle  18   d  via connecting line  32   d;      Electric vehicle  18   a  is charged from power source  14  for a time duration t d(d) , represented by the dotted line  44 ;   Advance, in sequence, to the next occupied stall (i.e. stall “f”);   Sensor  24  identifies that electric vehicle  18   f  in stall “f” is connected to system  10 ;   Controller  28  connects with electric vehicle  18   f  via connecting line  32   f;      Electric vehicle  18   f  is charged from power source  14  for a time duration t d(f) , represented by the dot-dash line  46 ; and   Reset N, if necessary and repeat T cycle .       
 
         [0043]    The essential tasks to be performed during an operation of the system  10  are presented in their interactive sequencing in the logic flow chart  48  shown in  FIG. 5 . Referring to the action block  50  in flow chart  48 , it will be appreciated that an initial set-up for the system  10  requires inputting the number n, which is the number of vehicle stalls provided for the system  10 , and also inputting the time duration, t d , that is to be used for charging each vehicle during a charging cycle. Preferably, t d  will be set for approximately ten minutes. After n and t d  have been input, action block  52  indicates that the system  10  monitors N, the actual number of vehicles  18  that are connected into the system  10 . 
         [0044]    When collectively considering the inquiry blocks  54  and  56  together with the action blocks  58  and  60  in flow chart  48 , it will be further appreciated that the system  10  has the capability of adjusting its configuration, depending on changes in N. Specifically, as N changes, it can be appropriately incremented whenever an additional electric vehicle  18  is connected into the system  10 , or it can be decremented whenever an electric vehicle  18  is disconnected and removed from the system  10 . In any event, the inquiry block  62  requires at least one electric vehicle  18  be connected into the system  10  before proceeding with a charging operation. 
         [0045]    Whenever N≧1, and with any changes in N being accounted for, the action block  64  requires that T cycle  be calculated. As previously disclosed elsewhere herein, this calculation is accomplished by setting T cycle =Nt d . This being done, action block  66  indicates that T cycle  is to be executed. At this point it is noteworthy to recall that T cycle  operates continuously. In particular, T cycle  is uninterrupted and bypasses empty stalls as long as N≧1. Moreover, it is continuously repeated until N=0. 
         [0046]    During an operation of the system  10 , inquiry block  68 , action block  70  and inquiry block  72 , collectively indicate that as T cycle  is being executed the electric vehicle  18  in a particular active stall (e.g. electric vehicle  18   f  considered above) will be charged during a time duration t d . Thereafter, action block  74  indicates that T cycle  is sequentially advanced to the next stall. On the other hand, whenever a particular stall a-f is empty, inquiry block  68  and action block  74 , together, indicate that the empty stall will be bypassed. 
         [0047]    While the particular System and Method for Charging a Plurality of Electric Vehicles 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.