Abstract:
A charging system is disclosed for charging a battery system of an electric vehicle. In one form, the charging system includes a first connector including a power control unit that is operable to selectively supply charging power from a power source. A second connector is connected with the first connector and includes a fault detection circuit. A controller is connected with the fault detection circuit and the power control unit. The controller is operable to control the power control unit to selectively supply charging power to a battery system if a fault is not detected from fault detection circuit. A cordset for use with the charging system is also disclosed that allows the cordset to perform certain electrical functions and connect the cordset to a connector of the vehicle in a breakaway manner.

Description:
PRIORITY 
     This application claims priority to and the benefit of U.S. Provisional Application No. 61/581,732 filed on Dec. 30, 2011. 
    
    
     BACKGROUND 
     Electric vehicles, such as golf carts for example, were traditionally used in specific settings such as factories or golf courses which would maintain the vehicles and could afford to purchase them. Energy efficiency is now a key issue in society due somewhat to the increasing costs associated with traditional fuels. Over the past several years, some new electric vehicles, also referred to as Neighborhood Electric Vehicles (“NEVs”), have gained in popularity. These vehicles are specifically designed for individuals to use as an alternative to fuel powered vehicles. A need exists for a safe and efficient manner to charge these types of vehicles that are normally used by average people not trained to work with and maintain these types of vehicles. 
     SUMMARY 
     One embodiment of the present application is a unique charging system for electric vehicles. Another embodiment is a cordset for use with a charging system. Other embodiments include methods, systems, apparatuses, devises, hardware and combinations for charging systems for electric vehicles. Further embodiments, forms, features, aspects, benefits and advantages of the present application will become apparent from the description and figures provided herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numeral refer to like parts throughout several views and wherein: 
         FIG. 1  is a block diagram of a charging system according to an embodiment. 
         FIG. 2  is a block diagram of a charging system according to another embodiment. 
         FIG. 3  is a circuit diagram of a charging system according to an embodiment. 
         FIG. 4  is a flowchart illustrating operations of a charging system according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a block diagram of a charging system according to an embodiment. In this embodiment, a vehicle  22  is coupled to a power source  10  by a cordset  11 . The vehicle  22  can be any variety of vehicle. For example, the vehicle can include a golf car, utility vehicle, passenger vehicle, or the like. 
     The vehicle  22  can be coupled to the power source  10  for charging an onboard battery system  32 . For example, the vehicle  22  can include a battery system  32  configured to provide electrical power for the vehicle  22 . Although in an embodiment, the battery system  32  can be the sole source of energy for the vehicle  22 , in another embodiment, the vehicle  22  can include other power sources, such as an internal combustion engine in a hybrid vehicle. 
     The cordset  11  can include a cable  12 , power control  14 , a cable  16 , and a connector  18 . The cable  12  can couple the power source  10  to the power control  14 . For example, the cable  12  can include a plug, such as a National Electrical Manufacturers Association (NEMA) 5-15P plug or the like. The power source  10  can include a corresponding receptacle. Accordingly, the cable  16  can be plugged into the power source  10 . 
     In another embodiment, the power source  10  can be connected to the power control  14  without connectors. For example the power control  14  can be installed in a wall box or other suitable housing and coupled to the power source  10 . The cable  16  and connector  18  can be exposed to a user to be coupled to a vehicle  22 . 
     The power source  10  can be any variety of power source. For example, the power source  10  can be an alternating current (AC) power source. However, in other embodiments, the power source  10  can be a direct current (DC) power source. 
     The power control  14  is configured to control whether power is delivered from the power source  12  to the vehicle  22 . As will be described in further detail below, the power control  14  can include switches, relays, actuators, other circuitry, or the like. The power control  14  can include switching of the power supply; however, other processing of the power can occur. For example, filtering, surge protection, rectification, or the like can occur in the power control  14 . 
     The vehicle  22  can include a connector  20 . The connector  20  can be coupled to an on-board charge system  26  of the vehicle  22 . Accordingly, the battery system  32  of the vehicle  22  can be charged through the cordset  11 . 
     The charge system  26  can be configured to control charging of the battery system  32 . The charge system  26  can include sensors  28 , actuators  30 , or the like. Examples of the sensors  28  and actuators  30  will be described in further detail below. 
     In an embodiment, the cable  16  can be coupled to the power control  14  through a breakaway connection  24 . For example, when multiple vehicles  22  are charging near each other, the cables  16  of the vehicles  22  can become tangled with other vehicles  22 . A user may drive the vehicle  22  while the cable  16  is still attached to both the vehicle  22  and the power control  14 . The breakaway connection  24  can be configured to release under such circumstances. For example, the breakaway connection  24  can be a modified connector with additional retention, such as a clamp, collar, compression device, or the like, that results in an additional amount of force to remove the connector. Such force can be below an amount that would damage the cable  16 , power control  14 , or the like, yet still be removable. 
       FIG. 2  is a block diagram of a charging system according to another embodiment. In this embodiment, the power source  50  is coupled to the plug  62  through a relay  54 . The relay  54  can be configured to selectively connect the conductors of the power source  50  with conductors  70  and  72  passing through the plug  62  and receptacle  74 . Here, the plug  62  and receptacle  74  can be the connectors  18  and  20  described above. Although the plug  62  and receptacle  74  will be used as an example, the connectors  18  and  20  can be any variety of connectors, different genders, genderless connectors, or the like. 
     The power control  52  can include an actuator  56  configured to control actuation of the relay  54 . In an embodiment, the actuator  56  can be powered solely through the conductors  66  and  68  passing through the plug  62  and receptacle  74 . However, in another embodiment, the actuator  56  can be coupled to the power source  50  through connection  58 . The control of the actuator  56  can still be provided through the plug  62  and receptacle  74 . 
     Cable  60  couples the power control  52  to the plug  62 . In particular, the cable  60  includes conductors for both power transfer and actuator control. For example, power can be supplied through conductors  70  and  72 . Control of the actuator  56  can be performed through the conductors  66  and  68 . Although a particular number of conductors for the power transfer and actuator control have been described, any number of conductors can be present as desired. For example, the supplied power can be three-phase power with three power conductors and a ground conductor. In another example, the power connection and actuator control can include a common conductor, such as a common ground. 
     In an embodiment, a load  64  can be coupled to the conductors  66  and  68  that are coupled to the actuator  56 . The load  64  can be disposed in the plug  62 . The load  64  can be any variety of devices. For example, the load  64  can include one or more electrical components, such as resistors, capacitors, inductors, active components, or the like. In a particular embodiment, the load  68  can be a device that can be sensed by the controller  88  through the sensor  84 . 
     Although a resistor will be used as an example, other components can be used, depending on what signal is used to actuate the actuator  56 . For example, any component or circuit that can induce a measureable difference when the plug  62  and receptacle  74  are connected can be used as the load  68 . 
     In an embodiment, a thermal device  78  can be disposed in the receptacle  74 . The thermal device  78  can be configured to have an electrical parameter that changes based on temperature. For example, the thermal device  78  can be a thermistor. In another example, the thermal device  78  can be a resettable fuse or polymeric positive temperature coefficient device. In these examples, as temperature changes, a resistance of the thermal device  78  changes. 
     In an embodiment, the controller  88  can be coupled to a power sensor  80 , an actuator  82 , and a sensor  84 . The power sensor  80  can be configured to sense if power is supplied through the receptacle  74 . The actuator  82  can be configured to actuate the actuator  56 . The actuator  82  can also be configured to apply a stimulus, bias, or the like to the conductor  86 . The sensor  84  can be configured to sense a voltage on the conductor  86 . However, in other embodiments, the sensor  84  can be configured to sense a current supplied to the conductor  86 . 
     As illustrated, the actuator  56  and vehicle share a common ground represented by conductor  68 . However, in another embodiment, a terminal of the actuator  56  need not include ground. For example, the actuator  56  can be drive differentially. The load  64  can still be placed in parallel with the actuator  56 . In such circumstances, a separate ground connection can, but need not be made through the plug  62  and receptacle  74  interface. 
       FIG. 3  is a circuit diagram of a charging system according to an embodiment. Referring to  FIGS. 2 and 3 , in this embodiment, the inductor  116  represents an actuator of a relay  54 . For example, the inductor  116  can be part of the relay  54 . In another example, the inductor  116  can be part of the actuator  56 . Resistor  114  represents the load  68 . Thermistor  112  represents the thermal device  78 . Transistor  108  and resistor  104  can represent the actuator  82 . Voltage sensor  102  can represent the sensor  84 . The resistor  104  is coupled between the node  100  and a power supply  106 . 
     Similarly, transistor  108  is coupled between node  100  and the power supply  106 . A current sensor  118  can be configured to sense a current through the transistor  108 . Although, the current sensor  118  is illustrated as sensing a collector current of the transistor  108 , the current sensor  118  can be configured to sense any current corresponding to the current supplied to the node  100 . Furthermore, although a bipolar transistor has been illustrated, any switching device can be used, including other transistor types, relays, or the like. 
     Before a plug  62  and receptacle  74  are mated, the inductor  116  (i.e., relay  54  or actuator  56 ) and the resistor  114  (i.e., load  64 ) are not coupled to the thermistor  112  (i.e., thermal device  78 ). At this point, the control input  110  can be supplied to turn off the transistor  108 . Accordingly, the node  100  is pulled up to the power supply voltage  106 . This voltage can represent a disconnected state. 
     Once the plug  62  and receptacle  74  are mated, the resistor  114  and inductor  116  are electrically connected to the node  100 . Thus, the voltage divider formed will create a new voltage on node  100 . This voltage can correspond to a connected state. In other words, a node that can be used to actuate the actuator  56  can also be used to determine a state, faults, or the like. 
     For example, various failures can be detected through the voltage on the node  100 . If the inductor  116  is shorted, the voltage will be pulled to a lower voltage. If the inductor  116  is open, the node  100  will be pulled to a higher voltage. Similarly, if the resistance of the thermistor  112  changes due to a high temperature, the voltage on node  100  can correspondingly change. Component values can be selected such that the voltages on node  100  during these various conditions are sufficiently different to be distinguishable by the sensor  102 . Accordingly, the voltage can be used by the controller  88  to determine a variety of faults before actuating the relay  54 . 
     In an embodiment, to actuate the actuator  56 , the control signal  110  can turn on the transistor  108 . Accordingly, the node  100  can be pulled to about the supply voltage  106 . This can energize the inductor  116  and hence, actuate the relay  54 . In an embodiment, during operation, the transistor  108  can be periodically turned off, allowing node  100  to return to a voltage that can be used to determine if a fault has occurred as described above. 
     In another embodiment, the current sensor  118  can be used to determine if a fault has occurred. For example, in normal operation, a particular current will be flowing through the transistor  108 . If the plug  62  is disconnected, the current can change, for example, to a lower value, since the resistor  114  and inductor  116  are no longer in the circuit. If the cable  60  has pulled away from the power control  52  or the inductor  116  has failed as an open, the current can again change, but to a different value as the resistor  114  in the plug  62  is still connected. 
     In an embodiment, changes in the resistance of the thermistor  112  can be reflected in the sensed current. For example, the thermistor  112  can be a positive temperature coefficient thermistor. As temperature increases in the receptacle, the resistance can increase, causing a decrease in the current, decrease in voltage across the inductor  116 , or the like. Eventually, the resistance can increase sufficiently such that the inductor  116  is no longer sufficiently energized to maintain an actuation of the relay  54 . 
     In this embodiment, the thermistor  112  can have multiple purposes. That is, the current can change, giving an indication of the temperature in the receptacle. In addition, the thermistor  112  can cause the power supply to be turned off due to a thermal overload. 
     Although a thermistor  112  with a linear and/or substantially continuous resistance versus temperature has been described, other components can be used. For example, a resettable fuse can perform a similar thermal shutdown function. Furthermore, a combination of such devices can be used. For example, a thermistor can be used in series with a resettable fuse to achieve a level of detail below a shutdown threshold temperature and a larger resistance change when a thermal shutdown is desired. 
     As described above, a power sensor  80  can be present. The controller  88  can be configured to receive the outputs of the various sensors, such as the power sensor  80  and sensor  84 , and use the outputs, in combination or individually, to monitor and control the supply of power, connection state, component status, or the like. For example, if the controller  88  receives a signal of a substantial increase in power from the power sensor  80 , the controller  88  can cause the actuator  56  to open the relay  54  thereby disconnecting the charge system  28  from the power source  50  so that the charging system is turned off. 
     In an embodiment, the controller  88  can be the controller for the actuator  56 . That is, the power control  52  can effectively be a passive device. The vehicle  76  can include the circuitry configured to drive the actuator  56 . 
     Moreover, in an embodiment, communication between the vehicle  76  and the power control  52  need not occur. Accordingly, the design of the power control  52  can be simplified. Communication interfaces, decoders, microprocessors, or the like involved in communication, maintain status information, monitoring or the like need not be included in the power control  52 . 
     In an embodiment, as selection of the value of the resistor  114  can be used to indicate a type of power source  50 . For example, if the power source  50  is a three-phase AC source, the resistor  114  can have a first value. If the power source  50  is a DC source, the resistor  114  can have a second value. If the power source  50  is a single phase AC source, the resistor  114  can have a third value. Any number of values can be selected to correspond to different power sources. The values can be selected such that the voltages on node  100  resulting from the different values can still be distinguished from the various failure conditions described above. 
     As described above, before the control input  110  is actuated to actuate the inductor  116 , the voltage of node  100  can be sensed. The controller  88  can be configured to use this sensed voltage to configure the charging system  26  to accept the power provided by the corresponding power source. That is, the charging system  26  can automatically reconfigure for different power sources. 
     Although relative DC voltages and/or currents have been used as examples of parameters for determining connections, faults, or the like, other signal parameters can be used. For example, amplitude and/or phase of an AC signal can be used. Furthermore, although particular voltage polarities, levels, or the like have been used, different polarities, levels, or the like can be used as desired. 
     In an embodiment, a substantially reduced number of components and thus, a reduced cost and complexity can be achieved. For example, the circuit of  FIG. 3  can achieve fault detection, connection detection, actuator control, and the like with a small number of components. 
       FIG. 4  is a flowchart illustrating operations of a charging system according to an embodiment. In this embodiment, the controller  88  can wait for a connection in  120 . For example, the voltage of node  100  can be monitored for a change indicating the load  64  has been electrically connected to the node  100 . 
     In  122 , initial fault detection can be performed. For example, using the voltage of the node  100 , a determination can be made to determine if a device is shorted, open, thermally overloaded, or the like. If so, corresponding fault processing can occur in  126 , such as preventing charging, setting an error flag, or the like. 
     Assuming that no faults are determined in  124 , charging can begin in  128 . As described above, the actuator  56  can be actuated to close the contacts of the relay  54 . However, in another embodiment, other functions can be performed. For example, the charge system can be reconfigured for a particular power source  50 . In another example, a status of the battery  32  can be determined. Any such functions related to charging can be performed. 
     Once charging begins, in  130  the system can be monitored for a fault. As described above, various currents and/or voltages can be used to sense a fault condition. If a condition is determined in  132 , fault processing can occur in  134 , such as deactivating the relay  54 , preventing charging for a time period, requiring a manual reset, or the like. If no fault is detected, the charging can continue in  136  and further fault monitoring can occur in  130 . 
     An embodiment includes a computer-readable medium storing computer-readable code that when executed on a computer, causes the computer to perform the various techniques described above. 
     Although particular sequences of operations have been described above, in other embodiments, the sequences can occur as desired. 
     Although particular embodiments have been described above, the scope of the following claims is not limited to these embodiments. Various modifications, changes, combinations, substitution of equivalents, or the like can be made within the scope of the following claims.