ELECTRIC VEHICLE SUPPLY EQUIPMENT
An electric vehicle charging system includes a portable housing having an integral holder to hold a connector for an electric vehicle supply circuit. An electric vehicle supply equipment enclosure includes an integral chamber to store all or part of a cord. A mounting bracket for an electric vehicle supply equipment enclosure covers an open portion of the enclosure. A method for facilitating use of an electric vehicle includes providing a prewiring kit for the electric vehicle. An electric vehicle supply equipment enclosure includes an integral disconnect switch. An electric vehicle supply circuit includes a grounding monitor circuit having automatic test functionality. Another electric vehicle supply circuit includes a contact monitor circuit to monitor the state of one or more of the contacts.
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The EVSE, which is also referred to as supply equipment, a vehicle charger, a charging station, a charger, etc., may be realized in several different mechanical configurations. EVSE are frequently installed as wall-mounted units in garages and on buildings where vehicles can be parked inside or close to the building. In outdoor locations, especially parking lots and curbsides, EVSE are commonly installed on pedestals. EVSE may also take the form of a cord set which is sometimes referred to as a travel charger, portable charger, handheld charger, etc.
The connector 16 and inlet 18 typically utilize a conductive connection in which the electrical conductors in one connector make physical contact with the electrical conductors in the other connector. Other systems utilize inductive coupling in which energy is transferred through magnetic coils that are electrically insulated from each other.
To promote interoperability of vehicles and supply equipment, the Society of Automotive Engineers (SAE) has developed various standards that define mechanical configurations of connectors for charging vehicles, as well as the arrangement and function of electrical contacts within the connectors. One standard known as SAE J1772 is of particular interest because virtually every automaker in the U.S., Japan and Europe has announced plans to use J1772 compatible connectors for models sold in the U.S. This standard relates to conductive charging systems and covers both AC and DC connections.
Terminal 5 of the coupling connects safety grounding conductors in the EVSE and the vehicle. A control pilot signal is connected through terminal 6 and enables basic two-way communications between the EVSE and the vehicle. For example, the control pilot enables a charge controller 36 in the vehicle to determine the maximum amount of AC current available from the EVSE, while it enables the EVSE to determine if the vehicle requires ventilation for charging and if the vehicle is ready to receive power. The return path for the control pilot signal is through the grounding path which enables it to serve a safety function: if the safety pilot signal is not present, control electronics 42 in the EVSE assumes the ground path has been compromised and causes the CCID to interrupt the flow of AC power to the vehicle.
A proximity device 40 enables the vehicle to verify that it is mechanically connected to an EVSE system. The implementation details of proximity detection are left to the discretion of the manufacturer, but the J1772 standard identifies the use of magnetic proximity detectors as an acceptable technique. For AC charging, only terminals 1, 2, 5, and 6 are required. DC charging requires the use of optional terminals 3 and 4, as well as the establishment of a more sophisticated communication link through optional terminals 7-9 which are not illustrated.
The J1772 standard defines different types of charging including AC Level 1, which utilizes the most common 120 Volt, 15 Amp grounded receptacle, and AC Level 2, which utilizes a dedicated AC power connection at 208-240 Volts nominal and 32 Amps maximum. DC charging is defined as a method that utilized dedicated direct current (DC) supply equipment.
Factors such as convenience, availability, reliability, effectiveness and the like of vehicle charging systems are important considerations for the design, functionality and ease of use/installation of EVSE. It is believed that such considerations will affect the widespread consumer adoption and acceptance of electric vehicles. Currently available charging systems are typically provided by systems integrators, network operators, utilities, and other organizations that are focused on high-level deployment issues, while possibly neglecting these considerations which will affect the end-user/installer experience.
Vehicle charging systems may seem conceptually simple, but numerous factors add layers of complexity that make it difficult to provide a satisfying user experience. For example, electric vehicle charging systems employ various safety features, but they tend to be inconvenient or plagued by nuisance tripping (e.g., charging circuit interruption as a result of a perceived fault condition). EVSE which has been shutdown/turned off as a result of a nuisance trip could result in a connected electric vehicle not receiving its user-anticipated charge overnight, and the user would be deeply disappointed to discover in the morning that the charging system turned itself off because of an incorrect fault determination.
For convenience, the term electric vehicle will be used to refer to pure electric vehicles (EVs), plug-in hybrid electric vehicles (PHEVs), and any other type of vehicle that utilizes electric charging unless otherwise apparent from context.
Referring to the rear view of
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The handle 66, front and rear plates 72 and 74, and any other portions of the housing may be provided with rounded corners and radiused edges as shown in the drawings, and other refinements for aesthetic and/or functional purposes.
The housing 58 may include relays, contactors, circuit boards, transformers, modules, lights, displays, charging circuits and/or any other components to implement an electric vehicle supply circuit such as a circuit for charging a vehicle with the cord set. For example, one embodiment may include circuitry to implement an AC Level 1 EVSE that operates from 120 VAC power and includes one or more indicator lights on the front plate to indicate the status of the power source, vehicle charge state, fault conditions, etc. As another example, a different embodiment may include circuitry to implement an AC Level 2 EVSE that operates from a dedicated source of 240 VAC power and includes an alphanumeric display with keypad and/or network capabilities. As a further example, another embodiment may include a charging circuit with an AC/DC converter to implement a DC charging EVSE.
The embodiments described above with respect to
The use of a recess in the housing to hold a connector may provide additional benefits. For example, it may be molded directly into the housing and, therefore, require few if any additional parts. Depending the shape and depth of the recess, it may protect the connector from moisture, dirt, sand and/or other foreign matter. It may also protect the connector from damage due to dropping, static electricity, and/or inadvertent contact with other electrical systems or devices, etc.
The mounting holes and slots may also provide additional benefits. The keyhole slots enable the housing to be easily mounted to a wall or other surface, or inside a vehicle. Combined with the overall shape and arrangement of the housing, this may provide a tidy and professional appearance. Using mounting holes with a standardized pattern enables existing mounting hardware to be repurposed for EVSE. It may be especially beneficial to use VESA standard hole patterns because an extensive range VESA mounting hardware is available. This hardware was designed for supporting monitors and televisions, but when combined with EVSE according to some of the inventive principles of this patent disclosure, it may provide unique arrangements that facilitate positioning of the EVSE to improve visibility, reduce glare, facilitate wrapping of cords, etc.
By designing the handle to accommodate hanging the housing on a hook or bracket, a manufacturer or supplier may provide a wall or pedestal mounted hook or bracket with a relatively large area to display any suitable indicia such as a trademark, instructions, or the like.
Each of the features described above may have independent utility and provide individual benefits. Moreover, when some or all of these features are integrated together, they may provide a superior overall user experience.
Some additional inventive principles of this patent disclosure relate to deployment systems for positioning a cord set or other portable EVSE in a vehicle and/or the marketplace. In one embodiment of a deployment system, a manufacturer or supplier of a portable EVSE may cooperate with a vehicle manufacturer to coordinate the interoperability of the EVSE and a vehicle. For example, the vehicle and EVSE designers may cooperate to provide a storage space in the vehicle that is custom designed to accommodate the portable EVSE. The storage space may be located in a trunk, under a seat, behind an interior or exterior panel, etc. One or more aspects of the portable EVSE such as a handle, flange, mounting holes, etc., may enable the EVSE to slide, snap or otherwise be secured in the custom storage space. This may prevent the EVSE from moving while the vehicle is in motion and/or taking up valuable interior space, and may present a well-organized and professional image to an end user.
Through a cooperative effort, the coordination of a portable EVSE and a vehicle may provide benefits for all of the stakeholders. It may, for example, establish a continuing market for the manufacturer or supplier of the portable EVSE and provide an opportunity to develop brand recognition. The manufacturer or supplier of the vehicle, as well as the end users, may also benefit from the improved functionality and closer integration of the EVSE into the vehicle.
The embodiments illustrated above with respect to
In some of the embodiments, the power cord is illustrated as being shorter than the charging cord, but the power cord may be of equal or shorter length (or any suitable length). In some embodiments, a power cord may be omitted entirely and replaced with another mechanism for providing input power to the cord set. For example, connector blades may be provided on the back of the housing to enable the cord set to be plugged directly into a wall outlet or extension cord. In this case, a hook or bracket may be mounted to a wall the correct distance from the receptacle to enable the handle to engage the hook and allow the housing to pivot into place and accurately position the blades for insertion into the receptacle. As another example, connector blades may be located in a recessed spot on the housing to accept the receptacle end of an extension cord, with or without strain relief.
In some of the embodiments, a power cord is illustrated as a 120 VAC plug for use with a National Electrical Manufacturers Association (NEMA) 5-15R receptacle, but other types of plugs and/or connectors may be used. Likewise, some of the embodiments are illustrated with a multi-prong shrouded connector such as a J1772 compatible vehicle charging connector, but other connectors, both conductive and inductive may be used.
For convenience, some embodiments are described using orientations such as front, rear, top, bottom, left, right, etc., but these are generally not intended to be limitations. For example, when placed on a horizontal surface, a rear surface may become the bottom and the front may become the top, etc.
In some embodiments, a vehicle charging connector is shown placed in a recess in the housing with the connection interface oriented in an inward direction; that is, the connector contacts generally face the housing. The connector, however, may be oriented in any suitable manner when docked. For example, the connector may be placed in the recess with the contacts facing away from the housing. This configuration may be useful for holding the connector when not in use, or even when it is in use. As a further example, the connector is shown held in a position where the connection interface is inside the perimeter of the housing, while a portion of the connector handle protrudes from the perimeter of the housing. In other embodiments, however, both the interface and the handle may fall within the perimeter of the housing. In still other embodiments, the entire handle of the connector may be located within the perimeter of the housing while the connector interface protrudes.
The size, shape and/or configuration, etc., of the vehicle charging connector may also be coordinated with the holder according to some inventive principles of this patent disclosure. For example,
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In some embodiments, a cord set is illustrated with a single connector holder, but any number of holders may be provided for vehicle charging connectors, power connectors, etc., for cord sets and/or other portable EVSE.
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The housing also includes two pivoting attachment points 81 (one of which is visible in the view of
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Though not visible, the housing may also include a pocket to provide an entry point for the charging cord which may also include a grommet and/or strain relief. The contours of the pocket may be angled so that the charging cord emerges from the pocket at an angle to facilitate wrapping the cord around the housing. Alternatively, another flat spot may be provided on the bottom edge of the rear flange or at any other suitable location to provide a point of entry for the charging cord. The handle 108, front and rear flanges 122 and 124, and any other portions of the housing may be provided with rounded corners and radiused edges as shown in the drawings, and other refinements for aesthetic and/or functional purposes.
As with the embodiments of
The inventive principles illustrated with respect to the embodiments of
The embodiments illustrated above with respect to
Some of the inventive principles of this patent disclosure relate to the use of a cord-and-plug power connection for EVSE systems that utilize dedicated power sources. An example of an EVSE system that utilizes a dedicated power source is an AC Level 2 charging system according to the SAE J1772 standard. This standard defines AC Level 2 charging as utilizing dedicated AC at a nominal voltage of 208-240 VAC and a maximum continuous current of 32 A. Prior art Level 2 EVSE enclosures are hard-wired to premises wiring.
According to some inventive principles of this patent disclosure, an EVSE system may include an electrical enclosure, an electric vehicle supply circuit disposed within the electrical enclosure and constructed and arranged to provide power to an electric vehicle from a dedicated power source, a power connector adapted to connect to a receptacle to receive power from the dedicated power source, and a power cord having a first end coupled to the power connector and a second end coupled to the electric vehicle supply circuit. In some embodiments, the electric vehicle supply circuit and the power connector may be adapted for AC Level 2 vehicle charging. The power connector may be, for example a NEMA 6-50 plug.
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The enclosure 148, especially the inner chamber 186, may include one or more relays, contactors, circuit boards, transformers, modules, lights, displays, charging circuits and/or any other components to implement an electric vehicle supply circuit such as a circuit for charging a vehicle. The panels of the enclosure, especially the front panel 150 may provide accessible locations for user interface devices such as displays, lights, switches, keypads, etc., as well as aesthetic design elements such as face plates, bezels, and the like.
In this configuration, the enclosure 148 may be mounted to a wall 196 or other surface directly over a receptacle 198 for the plug 192 as shown in
In some other embodiments, the plug 192 may be held rigidly in place with respect to the enclosure so that the prongs of the plug may be inserted into a receptacle as the enclosure is mounted on the wall or other structure. In yet other embodiments, the power cord 190 and plug 192 may be replaced or supplemented with a separate set of prongs which are rigidly attached to the enclosure so the separate set of prongs may be inserted into a receptacle as the enclosure is mounted on the wall or other structure.
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The mounting bracket and/or enclosure may be any suitable size and shape. In the examples illustrated in
Some additional inventive principles of this patent disclosure relate to providing a combination of connection methods for charging vehicles. For example, the enclosure illustrated in
The embodiments and inventive principles described and illustrated with respect to
The inventive principles relating to plug-and-cord connected EVSE described above may provide one or more advantages. For example, the best location for mounting a vehicle charger may not be known in advance of receiving the EVSE, which may not be provided to the user until taking delivery of a vehicle. Level 2 charging involves the use of dedicated power circuits at relatively high voltage and/or current levels. If the user waits until receiving the EVSE and/or vehicle, there may be an additional wait to have the EVSE installed.
The use of a plug-and-cord connected EVSE according to the inventive principles of this patent disclosure may enable the user to have a suitable receptacle installed in a best-guess location well in advance of receiving the EVSE and/or vehicle, thereby eliminating potential scheduling delays. Upon taking delivery, the EVSE may then be mounted immediately. If the best-guess location turns out to be ideal or acceptable, the EVSE may be plugged in and mounted directly over the receptacle with the cord and plug concealed entirely within the chamber and/or enclosure. Even if the location of the receptacle turns out to be unacceptable for the EVSE itself, the receptacle can still be used immediately by mounting the EVSE in an acceptable location, then extending the power cord from the EVSE to the receptacle through one of the knockouts. Any excess cord may be concealed within the chamber and/or enclosure with only the minimum amount of cored exposed to reach the receptacle.
Moreover, the use of plug-and-cord connected EVSE according to the inventive principles of this patent disclosure may facilitate future relocation, upgrade, etc. of the EVSE. If the user decides to relocate the EVSE, it may be accomplished without having to move any hard wiring. Likewise, if a failed unit must be replaced, or the user decides to upgrade to EVSE having a higher charging capacity, more features, etc., it may be replaced without removing or changing any hard wiring.
Some additional inventive principles of this patent disclosure involve methods and apparatus relating to prewiring for EVSE. For example, a vehicle manufacturer or supplier, an electric utility, or other facilitator may provide a user with a prewire kit as part of a sales transaction, electric vehicle promotion, etc. A prewire kit may include various combinations of components and/or other elements according to some of the inventive principles of this patent disclosure. For example, in one embodiment, a prewire kit may include a standard power receptacle and instructions, recommendations, or the like in paper, electronic, online, etc. form. Alternatively, the device may be supplied with built-in memory which may automatically supply any suitable information upon power up in a pop-up fashion (i.e.—similar to the pop-up notification when a CD is inserted into a computer. In another embodiment, a prewire kit may include a receptacle, a wall box, and a mounting bracket for the EVSE. Since some power receptacles may be unsightly and/or make some people feel uneasy, especially with higher power receptacles and/or households with children, an outlet cover may be included in a prewiring kit to cover and protect the receptacle while not in use. In yet other embodiments, a prewire kit may include a plug-in EVSE unit or an EVSE wiring device as described above and/or below.
An embodiment of a method according to some inventive principles of this patent disclosure may include providing an electric vehicle to an electric vehicle user, and providing a prewiring kit to the electric vehicle user. The prewiring kit may include one or more components adapted to facilitate connection of electric vehicle supply equipment to premises wiring at the electric vehicle user's premises.
The inventive principles described above with respect to the embodiments of
As explained above, the use of a chamber or other cord management according to the inventive principles may provide a more professional looking installation because it may conceal excess cord. Moreover, this may enable the manufacturer to provide all models with the same cord length, there by reducing the costs and logistics associated with fabricating and stocking multiple models with different cord lengths.
As a further potential benefit, a mounting bracket for an EVSE enclosure may be used as an enclosure panel, even if it is not used as a mounting bracket. For example, in the embodiment of
Although the embodiments of
As with all of the embodiments described in this patent disclosure, the embodiments described and illustrated with respect to
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The embodiment of
Some additional inventive principles relate to electric vehicle supply circuits for EVSE. An electric vehicle supply circuit is designed to provide power to an electric vehicle from a power source and includes at least an interrupting device and control circuitry to cause the interrupting device to interrupt the flow of power from the power source to the electric vehicle in response to conditions relevant to electric vehicles. Examples of conditions relevant to electric vehicles include a ground fault condition, an inoperable grounding monitor circuit, the absence of a vehicle connected to the EVSE, absence of a ready signal from the vehicle, etc.
The embodiment illustrated in
In the case of electric vehicle charging, however, 5 mA may be an unacceptably low trip point. Natural nonhazardous current paths through the vehicle to ground may routinely exceed 5 mA, thereby causing excessive nuisance tripping that interrupts the charging process. Therefore, UL standards allow a CCID to have a trip point of 20 mA if the system is equipped with a grounding monitor that interrupts the power circuit if it detects an inadequate grounding circuit. UL standards also require a CCID to allow for manual testing or automatic testing before each operation.
The grounding monitor circuit 254 monitors the continuity of a grounding conductor and generates an output signal GMO in response to the state of the grounding conductor. A manual test input GMMT enables the operation of the grounding monitor to be tested manually. An automatic test input GMAT enables the operation of the grounding monitor to be tested in response to an automatic test signal from a controller 262. The output signal GMO is provided to the controller 262 as well as logic 264.
The ground fault detecting circuit 256 monitors the differential current through the current carrying conductors and changes the state of the output signal GFO if the differential current exceeds a threshold. A manual test input GFMT enables the operation of the ground fault detector to be tested manually, while a manual reset input GFMR allows the detector to be reset manually. Automatic test input GFAT and automatic reset input GFAR enable the controller 262 to test and reset the ground fault detector. The output signal GFO is applied to the controller 262 as well as logic 264.
The contactor circuit 258 is arranged to close the circuit between the power source and the vehicle connector 260 in response to a CLOSE input signal from logic 264.
The contact monitor circuit generates an output signal CMO in response to the state of one or more switches in the contactor circuit 258. An automatic test input CMAT enables the controller 262 to test and monitor the contactor circuit.
A control pilot connection 266 enables the controller to determine whether a vehicle is connected to the supply circuit, to determine whether the vehicle is ready to receive power, to communicate the current capacity of the supply circuit to the vehicle, etc.
Logic 264 may be configured for interlocking operation. For example, the logic may be configured to assert the CLOSE signal only if the GMO signal indicates that the grounding monitor circuit is operating properly, the GFO signal indicates that no ground fault is present, and the controller asserts the CTRL signal.
The controller 262 may be configured to operate any or all of the features illustrated in
The microcontroller 270 includes digital I/O lines coupled to the test, monitor and reset signals shown in
Indicators 274 such as LEDs, lamps, etc. enable the controller to provide a visual indication of the operating condition of the vehicle supply circuit, fault conditions, etc. Some example indicators include a vehicle charging indicator and an EVSE fault indicator.
Operator inputs 276 such as switches, keypads, swipe cards, RFID devices, etc., enable a user to control the operation of the vehicle supply circuit. Some example inputs include switches to start/stop charging, switches to increase/decrease amperage, etc.
A display 278 enables the controller to provide more information to a user than may be conveyed through simple indicators. For example, an alphanumeric display may display vehicle charging current, voltage and/or power, percentage of charging completed, elapsed charging time, cost of power, etc. A display may also provide more detailed information about fault conditions and/or instructions for correcting faults.
A power meter 280 or other device may provide functionality to measure the amount of power transferred through the vehicle supply circuit, obtain authorization for power usage from a utility or other provider, facilitate off-peak rate reductions and/or demand response functions, etc. The power meter may be utility-grade for billing purposes, or it may be a convenience feature. It may be integral with the controller or separate from the controller, for example, in a tamper-proof enclosure. The power meter may be implemented, for example, with a dedicated integrated circuit (IC) such as a Microchip MCP3909 which may be mounted on a main circuit board with the microcontroller 270. Alternatively, the power meter may be arranged on a separate circuit board that may be attached to the main circuit board through a plug-in header to facilitate implementation of the power meter as an optional feature.
A network interface 282 may enable the controller to interface to any suitable network such as a local area network (LAN), wide area network (WAN), home network, the Internet, a control area network (CAN) or other industrial type control network, etc., through any type of network media and using any type of network protocol. Examples include dedicated wires, power line modulation, radio frequency (RF), infrared (IR), and other types of media, Internet Protocol (IP), WiFi, LonWorks, ZigBee, Z Wave, and other types of protocols.
The inventive principles described above respect to the embodiments of
In a 120 VAC system, L1, N and GND may designate the hot, neutral and grounding conductors, respectively. In a 240 VAC system, L1, L2 and GND may designate the two hot conductors and the grounding conductor, respectively. Other systems, for example 3-phase power systems, may include different combinations of live and grounding conductors.
In the circuit of
Actuating the manual test switch interrupts the monitor current path and causes the optocoupler to stop pulling up the monitor signal GMO. The controller or other decision making circuit may respond to the change of state of GMO by interrupting the flow of power to a vehicle and/or any other suitable actions.
The solid state relay RL5 enables the ground monitor circuit to be tested automatically by a controller or any other suitable apparatus. A logic high on the automatic test signal GMAT turns the switch side of RL5 off, thereby interrupting the monitor current path and causing the optocoupler to stop pulling up the monitor signal GMO. This enables the controller to confirm the correct operation of the ground monitor circuit. In this case, rather than actuating a CCID, the controller may drive GMAT low again, and after confirming that GMO goes high again, return to a normal monitoring mode of operation.
The current carrying conductors L1 and L2/N both pass through a differential transformer T1 and neutral-ground (N-G) transformer T2, which are connected to a ground fault interrupter (GFI) circuit 268. The GFI circuit includes circuitry to detect differential currents flowing through L1 and L2/N and trigger the silicon controlled rectifier (SCR) labeled SC1 when the differential current exceeds a threshold determined by resistor R10. The GFI may be based on a commercial or special-purpose GFCI integrated circuit such as the LM1851 chip from National Semiconductor or the FAN1851 chip from Fairchild.
In a conventional ground fault detection circuit, the SCR actuates a latching relay arrangement. In the embodiment of
When SC1 is triggered in response to a ground fault detection, it latches in the conductive state and causes Q1 to turn off, thereby causing the ground fault monitor signal GFO to go low. SC1 may be reset by closing the manual reset switch. A normally-open solid state relay RL4 enables the GFI circuit to be reset automatically by a controller and/or other decision making circuit or suitable apparatus in response to a ground fault automatic reset signal GFAR. A logic high on GFAR turns on the LED on the input side of RL4 through a current limiting resistor R16. Light from the LED turns on the FET switches on the output side of RL4, thereby resetting SC1.
The circuit of
Another normally-open solid state relay RL3 enables the GFI circuit to be tested automatically by a controller and/or other decision making circuit or suitable apparatus by driving the ground fault automatic test signal GFAT with a logic high. A high signal on GFAT turns on the LED on the input side of RL3 through a current limiting resistor R15. Light from the LED turns on the FET switches on the output side of RL3, thereby causing a test current to flow through R14 without passing through the transformers T1 and T2.
The GFI supply +VS is referenced to a local ground connection at node N3 and may be provided, for example, by a rectifier bridge connected to the current carrying conductors L1 and L2/N. One or more resistors may be connected in series with the bridge to reduce the supply voltage to an acceptable level for the GFI circuit 268. For example, commonly available GFCI chips such as the LM1851 typically include an internal voltage regulator that clamps the supply voltage to about 26 Volts.
During normal operation, if the contacts of the monitored relay are closed and AC power is available, current flowing through the input side of optocoupler U19 turns on a phototransistor which pulls the contact monitor output signal CMO to a high logic level through resistor R68 referenced to a logic supply voltage +V and an associated logic ground. If the contacts are open and/or AC power is not available, no current flows through the monitor current path and the optocoupler stops pulling up the monitor signal CMO. The CMO signal may be monitored by a controller or other apparatus to confirm that the contacts are actually open or closed when expected.
The normally-closed solid state relay RL6 provides additional functionality by enabling an automatic test feature. During a time when AC power is expected on LINE 1 and LINE 2, the contact monitor automatic test signal CMAT may be driven high to turn the switch side of RL6 off, thereby interrupting the monitor current path and causing the optocoupler U19 to stop pulling up the monitor signal CMO. This enables a controller or other apparatus to confirm the correct operation of the contact monitor circuit.
In any of the embodiments of
Some additional inventive principles of this patent disclosure relate to fault circuit self-testing for EVSE. For purposes of illustration, some of the inventive principles are described in the context of a ground fault detector, but the inventive principles are also applicable to other types of fault circuits that may be used in EVSE such as arc fault detectors, over-current detectors, etc.
Ground/Neutral transformer T1 is connected to the IC through a capacitor network including C6 and C7. The differential sense transformer T2 is connected to the IC through a network including capacitors C8-C10, resistor R11 and voltage regulator diode Z2.
The differential fault current threshold (sensitivity) for the IC is determined by the current flowing into the RES terminal (pin 6) through resistor R10. The timing or integrating capacitor C3 is charged by a fault current when the IC 271 detects a fault condition. When the voltage on C3 reaches a predetermined limit, the SCR output (pin 1) is driven high which triggers the SCR SC1 through resistors R7 and capacitor C2, which provides noise protection from accidental triggering.
To simulate a fault condition during an automatic testing process, a fault simulation circuit such as the auto test circuit including R15, RL3 and R14 shown in
A trigger connection TRIG may be provided to the gate of SC1 to enable the self-test controller to control SC1. For example, the TRIG connection may have three different states: a high-impedance state that enables the IC 271 to control SC1 as it normally would in a conventional operating mode; a low output or pull-down state that clamps the gate of SC1 to a low level to prevent it from triggering even if the IC 271 tries to trigger it; and a high output or pull-up state that triggers SC1 regardless of the state of the output (pin 1) of the IC 271.
A sense connection SENSE may be provided to enable the self-test controller to read the state of the SCR output (pin 1) of the IC 271.
A timing circuit 275 includes a transistor Q1 which turns on in response to a signal P_CTL and discharges the timing capacitor C3 through a resistor R270. This causes the timing capacitor to discharge more rapidly than it normally would under the control of the IC 271.
A zero crossing detection circuit 273 generates a zero crossing signal ZC which may enable a self-test controller to determine when the AC input voltage on L1 and L2/N crosses zero, as well as other information such as the line voltage, polarity of a half-cycle, etc. The zero crossing detection circuit may be implemented, for example, with a resistive voltage divider connected to the AC input voltage and referenced to the local ground node. If used in combination with a zero crossing detector, the optocoupler RL3 may be used to apply a fault condition to the system during any selected portion of a line cycle or half-cycle.
In some embodiments, the self-test controller may be implemented as a dedicated controller. In other embodiments, the self-test control functionality may be integral with other control functionality such as that provided by the controller 262 illustrated in
The apparatus illustrated in
If, however, the SENSE signal is activated earlier than expected, this may indicate that an actual external fault condition exists. The self-test controller may then release the TRIG signal immediately to enable IC 271 to trigger the SCR and open the contacts. Alternatively, the self-test controller may activate the TRIG signal to trigger the SCR and open the contacts.
In some embodiments, the self-test controller may activate the P_CTL signal at the end of a self-test process to enable the timing circuit 275 to rapidly discharge the timing capacitor C3. This may reduce the time required to put the fault circuit back online for detecting actual faults once a self test is completed.
In some embodiments, the self-test controller may be programmed to perform a self test across at least two different half cycles of opposite polarity. The determination of the timing of the self test may be based upon timing performed by the self-test controller in combination with the zero crossing detection circuit 273. Both the polarity and timing of a zero crossing are detected with the help of the zero crossing circuit 273. If a self test is conducted during the existence of an external fault that was below a trip limit, then this condition could result in a false failure of a self test. Because the system may be configured to conduct the self test across at least two different half cycles of opposite polarity, this self test may not be affected by the presence of a standing external fault. This is because with at least one of the embodiments described above, the self test simulated fault signal may be a rectified fault signal. If during the self test, the SENSE signal goes high at the half cycle or during a period of time when a test fault is not applied, this means that an external fault caused the tripping and the self-test controller will unblock the SCR to allow the IC chip 271 to trip the solenoid.
During charging, the voltage on timing capacitor C3 grows, and when it reaches its threshold value, pin 1 on the IC 271 goes high, and causes triggering of the SCR SC1. The triggering of the SCR provides current to the pilot solenoid RL2 of
In some embodiments, the SENSE signal from the fault detection IC 271 is coupled to the self-test controller to enable the controller to determine that the fault detector IC 271 has detected a fault. In this case, during a fault, either external or internal, when fault detector IC 271 generates a fault signal, the output from fault detector IC 271 flows not only to the SCR but also to the self-test controller to indicate to the self-test controller that a fault has occurred. The SENSE input to the self-test controller is significant because if during a test cycle, there is no active signal from pin 1 of fault circuit IC 271 into the self-test controller, then this result would provide an initial indication that fault circuit IC 271 has failed or at least that another component monitored by the self test has failed. In this case, self-test controller is programmed to conduct a self test over at least two different half cycles of different polarities. In at least one embodiment, these different half cycles can be consecutive half cycles. The simulated fault signals that are generated are introduced by the self-test controller in combination with the fault simulator such as RL3 in
In some embodiments, a temperature sensor 277 may be included. The temperature sensor 277 can comprise a circuit utilizing a resistor, a thermistor, or any other known sensor circuitry for determining the ambient temperature of the device. If necessary, the self-test controller can include an additional connection to this temperature sensor to form a closed circuit. The temperature sensor is used to determine the ambient temperature of the device, wherein the self-test controller includes programming to trip the contacts in the event it detects that an operating temperature, or an ambient temperature sensed by temperature sensor 277 is too high or too low.
In some embodiments, connections to the disconnect switch may be accessible through a separate opening in the enclosure, for example by removing a dedicated panel. In other embodiments, connections to the disconnect switch may be accessible through one or more shared openings with the electric vehicle supply circuit.
For example, in one embodiment the device may not be able to disconnect the receptacle 312 from the blades 310. The device may only have monitoring circuitry to display charging voltage, current, power, etc., on a display 314. Buttons 316 may enable a user to select a parameter to view, scroll through various parameters or menu items, etc.
In another embodiment, the plug-in device of
In other embodiments, the device of
The inventive principles described and illustrated above with respect to
Although described in the context of an EVSE system, the inventive principles are applicable to displaying parameters for any type of electrical equipment including a power distribution unit (PDU), a power conditioning unit (PCU) and the like.
Referring to the state diagram of
If a button press is detected before the time period T1 expires while displaying the first parameter P1 in state 370, the method proceeds to state 376 where the first parameter P1 is displayed indefinitely until another button press is detected. A button press in state 376 causes the process to change to state 372 and resume scrolling through all parameters.
Likewise, if a button press is detected before the expiration of T1 while scrolling through any of the other parameters in states 372 and 374, the currently displayed parameter is held indefinitely until another button press returns the system to scrolling.
In one example EVSE embodiment, the parameters to be displayed may be charge rate, elapsed charging time, and charge time remaining. When a first user begins charging a vehicle, the EVSE may begin scrolling through all three parameters on a display. The first user may be most interested in the charge time remaining, and therefore, the user can press a button to hold the display on the charge time remaining parameter. A second user, who may be more interested in the charge rate may later press the button to begin scrolling, then press the button again when the charge rate is displayed to hold that parameter on the display.
In one example PDU embodiment, the parameters to be displayed may be voltage, current and power. On start up, the display my scroll through all three parameters until a user presses a button to hold a parameter of interest on the display.
In some embodiments, the display may include an indication of the parameter being displayed. In other embodiments, one or more ancillary display devices may be included to indicate the parameter being displayed. For example, in the embodiment of
The inventive principles related to displaying parameters are not limited to the specific details described above. For example, any number of parameters may be displayed for any lengths of time. Different time periods may be used to time out while scrolling between parameters, i.e., more important parameters may be displayed for longer periods of time, or at more frequent intervals than other parameters. The examples have been described above in the context of button presses, but any other inputs may be used to change between states, including remote inputs, wireless inputs, other actions, events, and/or lack of actions, events. For example, the detection of a fault or alarm condition such as an over current condition may cause the display to stop scrolling and display the current or other parameter most relevant to the fault or alarm condition.
The interface 402 may include any suitable mechanical interface to accept a communication module including a slot, bay, socket, etc., and any suitable electrical interface to enable the EVSE to communicate through the module including a card-edge connector, plug and receptacle, ribbon cable, etc., to establish serial data connection, parallel data connection, etc. with the module. A module may be realized in any suitable mechanical and/or electrical form to operate with the interface.
Having modular communications may provide a flexible solution that enables the EVSE to adapt to changing market conditions, supply conditions, user preferences and/or needs, etc. For example, a specific type of communication protocol such as Z-Wave may be popular in a particular market where the local utility is promoting a new standard such as ZigBee Smart Energy 2.0. The local utility may require new EVSE to include the new standard, but hardware for the new standard may not be widely available yet, it may be prohibitively expensive, or it may lack user acceptance. By providing a modular interface, an EVSE manufacturer or supply may initially ship a unit with the more common or acceptable Z-Wave module, but still enable the conversion to the new standard when required by the utility or accepted by the user.
The inventive principles relating to WiFi may be implemented even without a modular interface. Current EVSE products typically have non-WiFi communication such as ZigBee, which is oriented to specialized applications such as automation and control systems and cannot interoperate with WiFi. However, WiFi has become popular with the general public WiFi routers have been installed in homes and businesses on a widespread basis. To promote acceptance of electric vehicles by the general public, it may be advantageous to enable consumers to interact with EVSE through a familiar interface such as WiFi. Thus, some of the inventive principles contemplate an embodiment of an EVSE system with a WiFi interface, which may be modular or built into the EVSE, that enables a user to check, for example, the charge status of an electric vehicle from a WiFi enabled computer or phone, while utilizing existing WiFi infrastructure.
Another embodiment of a communication module according to some of the inventive principles may operate on any version of the ZigBee Smart Energy standard including version 2.0. Such an embodiment may combine wireless and power line carrier (PLC) technology in a modular form that may be utilized for locations or utilities that require a ZigBee interface.
Another embodiment of a communication module according to some inventive principles may provide Z-Wave compatible functionality. An benefit of a Z-Wave compatible module is that is may enable an EVSE to interoperate with a wide range of existing products such as remote controls, serial communication modules, etc., many of which may be consumer oriented products that users may have developed a level of comfort and acceptance with.
According to some inventive principles of this patent disclosure, a system includes: an electrical enclosure; an electric vehicle supply circuit disposed within the electrical enclosure and constructed and arranged to provide power to an electric vehicle from a power source; and a disconnect switch integral with the enclosure and arranged to disconnect the electric vehicle supply circuit from the power source. In some embodiments, the disconnect switch comprises a safety disconnect, the disconnect switch comprises an electro-mechanical switch, and/or, the disconnect switch comprises a rotary actuator.
According to some inventive principles of this patent disclosure, an electric vehicle supply circuit includes: a charge circuit interrupting device having one or more contacts arranged to interrupt power to an electric vehicle; a contact monitor circuit coupled to the charge circuit interrupting device; and a controller coupled to the contact monitor circuit and the charge circuit interrupting device, where the controller is constructed and arranged to control the charge circuit interrupting device in response to the contact monitor circuit; where the contact monitor circuit includes automatic test functionality to enable the controller to test the operation of the contact monitor circuit. In some embodiments, the contact monitor circuit comprises a resistor and a switch coupled in series between two current carrying conductors, where the switch is constructed and arranged to be operated by the controller. The switch may comprise an optically isolated coupling. The grounding monitor circuit may further comprise a monitor device coupled in series with the resistor and switch and arranged to enable the controller to monitor the operation of the contact monitor circuit. The monitor device may comprise an optically isolated coupling.
According to some inventive principles of this patent disclosure, a method includes: displaying a first parameter in a display for an electric apparatus; displaying a second parameter in the display if a user input is not received before the end of a first predetermined time period; and displaying the first parameter for a second time period if a user input is received before the end of the predetermined time period. In some embodiments, the method may further include; displaying a third parameter in the display if a user input is not received before the end of a third predetermined time period; and displaying the second parameter for a fourth time period if a user input is received before the end of the third predetermined time period. Displaying the first parameter for a second time period may comprise: displaying the first parameter until a user input is received; and displaying the second parameter after the user input is received. The second time period may comprise a predetermined time period, and displaying the first parameter for a second time period may comprise displaying the first parameter until a user input is received or until the end of the second time period. The method may further include indicating a type of the first parameter in the display while displaying the first parameter. The method may further include indicating a type of the first parameter with an ancillary display while displaying the first parameter. The electric apparatus may comprise electric vehicle supply equipment and/or a power distribution unit.
According to some inventive principles of this patent disclosure, a system includes: electric vehicle supply equipment; and a modular interface to enable the electric vehicle supply equipment to communicate with one or more communication modules. In some embodiments, the system may further include a communication module adapted to connect to the modular interface. The communication module may comprise wireless functionality. The communication module may comprise: a microcontroller; an interface to couple the communication module to the electric vehicle supply equipment; and a wireless transceiver coupled to the microcontroller.
The inventive principles of this patent disclosure have been described above with reference to some specific example embodiments, but these embodiments can be modified in arrangement and detail without departing from the inventive concepts. Thus, any changes and modifications are considered to fall within the scope of the following claims.
Claims
1. A system comprising:
- a portable housing;
- an electric vehicle supply circuit disposed within the portable housing and constructed and arranged to provide power to an electric vehicle from a power source;
- an electric vehicle charging connector;
- a charging cord having a first end coupled to the electric vehicle charging connector and a second end coupled to the electric vehicle supply circuit; and
- a holder integral with the portable housing to hold the electric vehicle charging connector.
2. The system of claim 1 where the holder comprises a recess in the housing.
3. The system of claim 2 where the recess has a contour that matches a contour of the electric vehicle charging connector.
4. The system of claim 1 where the holder comprises a frame attached to the housing.
5. The system of claim 4 where the frame is movable relative to the housing.
6. The system of claim 5 where the fame may slide relative to the housing.
7. The system of claim 4 where the frame may be configured to function as a hanger for the charging cord.
8. The system of claim 1 where the housing comprises a mechanism to attach the housing to a structure.
9. The system of claim 8 where the mechanism comprises a slot.
10. The system of claim 8 where the mechanism comprises a handle.
11. The system of claim 10 where the handle is movable relative to the housing.
12. The system of claim 1 further comprising:
- a power connector; and
- a power cord having a first end coupled to the power connector and a second end coupled to the electric vehicle supply circuit.
13. The system of claim 1 further comprising a storage connector configured to engage a charging connector when the charging connector is not in use.
14. The system of claim 13 where the storage connector is configured to engage a latch on the charging connector.
15. The system of claim 13 where the storage connector is rotatably attached to the housing.
16. A system comprising:
- an electrical enclosure;
- an electric vehicle supply circuit disposed within the electrical enclosure and constructed and arranged to provide power to an electric vehicle from a power source;
- a power connector; and
- a power cord having a first end coupled to the power connector and a second end coupled to the electric vehicle supply circuit;
- where the electrical enclosure includes an integral chamber to store all or part of the power cord.
17. The system of claim 16 where the chamber is contained entirely within the enclosure.
18. The system of claim 16 where the chamber is at least partially open to allow access to a structure on which the enclosure is mounted.
19. The system of claim 16 where the chamber includes an opening to allow the cord to pass outside of the enclosure.
20. The system of claim 19 where the opening comprises a knockout.
21. The system of claim 16 where the chamber is separated from an inner portion of the enclosure.
22. The system of claim 21 further comprising an opening between the chamber and the inner portion of the enclosure.
23. The system of claim 22 where the opening comprises a knockout.
24. The system of claim 22 where:
- the electric vehicle supply circuit is located in the inner portion of the chamber; and
- the power cord is coupled to the electric vehicle supply circuit through the opening between the chamber and the inner portion of the enclosure.
25. The system of claim 16 where the chamber is at least partially open to allow the power connector to be plugged into a receptacle on a structure to which the enclosure is mounted.
26. The system of claim 16 further comprising a mounting bracket to cover at least a portion of the chamber.
27. The system of claim 26 where the mounting bracket may function as a panel for the enclosure.
28. The system of claim 26 where the mounting bracket is arranged to be attached to building members having standardized spacing.
29. The system of claim 26 where the mounting bracket includes a portion that is exposed when attached to the enclosure.
30. The system of claim 29 further comprising a holder for an electric vehicle charging connector arranged to cover at least a portion of the exposed portion of the mounting bracket.
31. The system of claim 16 where the enclosure comprises a sloped top.
32. The system of claim 16 where the system further comprises a channel arranged at the top of the enclosure to receive a cord.
33. The system of claim 32 where:
- the system further comprises a cap arranged at the top of the enclosure; and
- the channel is formed in the cap.
34. A method comprising:
- providing an electric vehicle to an electric vehicle user;
- providing a prewiring kit to the electric vehicle user, where the prewiring kit includes one or more components adapted to facilitate connection of electric vehicle supply equipment to premises wiring at the electric vehicle user's premises; and
- providing the electric vehicle supply equipment to the electric vehicle user.
35. The method of claim 34 where the prewiring kit comprises a receptacle.
36. The method of claim 35 where the prewiring kit comprises a receptacle cover.
37. The method of claim 34 where the prewiring kit comprises a mounting bracket for electric vehicle supply equipment.
38. The method of claim 34 where the prewiring kit comprises electric vehicle supply equipment.
39. The method of claim 38 where the electric vehicle supply equipment comprises a wiring device.
40. The method of claim 38 where the electric vehicle supply equipment comprises a plug-in device.
41. An electric vehicle supply circuit comprising:
- a charge circuit interrupting device arranged to interrupt power to an electric vehicle;
- a grounding monitor circuit; and
- a controller coupled to the grounding monitor circuit and the charge circuit interrupting device, where the controller is constructed and arranged to control the charge circuit interrupting device in response to the grounding monitor circuit;
- where the grounding monitor circuit includes automatic test functionality to enable the controller to test the operation of the grounding monitor circuit.
42. The circuit of claim 41 where the grounding monitor circuit comprises a resistor and a switch coupled in series between a hot conductor and a grounding conductor, where the switch is constructed and arranged to be operated by the controller.
43. The circuit of claim 42 where the switch comprises an optically isolated coupling.
44. The circuit of claim 42 where the grounding monitor circuit further comprising a monitor device coupled in series with the resistor and switch and arranged to enable the controller to monitor the operation of the grounding monitor circuit.
45. The circuit of claim 44 where the monitor device comprises an optically isolated coupling.
46. An electric vehicle supply circuit comprising:
- a charge circuit interrupting device arranged to interrupt the flow of power from a power source to an electric vehicle;
- a fault monitor circuit; and
- a controller coupled to the fault monitor circuit and the charge circuit interrupting device, where the controller is constructed and arranged to control the charge circuit interrupting device in response to the fault monitor circuit;
- where the fault monitor circuit includes automatic test functionality to enable the controller to test the operation of the fault monitor circuit.
47. The circuit of claim 46 further comprising a zero crossing detection circuit coupled to the controller and is constructed and arranged to detect a zero crossing of the power source.
48. The circuit of claim 46 where the fault monitor circuit comprises a GFCI integrated circuit.
49. The circuit of claim 46 further comprising a sense connection between the fault monitor circuit and the controller to enable the controller to determine that the fault monitor circuit has detected a fault during a self-test process.
50. The circuit of claim 46 further comprising a trigger connection between the fault monitor circuit and the controller to enable the controller to prevent the fault monitor circuit from triggering the charge circuit interrupting device during a self-test process.
51. The circuit of claim 46 further comprising a trigger connection between the fault monitor circuit and the controller to enable the controller to prevent the fault monitor circuit from triggering the charge circuit interrupting device during a self-test process.
52. The circuit of claim 46 further comprising a timing control circuit constructed and arranged to enable the controller to change a timing parameter of the fault monitor circuit.
53. A system comprising:
- an electrical enclosure;
- an electric vehicle supply circuit disposed within the electrical enclosure and constructed and arranged to provide power to an electric vehicle from a dedicated power source;
- a power connector adapted to connect to a receptacle to receive power from the dedicated power source; and
- a power cord having a first end coupled to the power connector and a second end coupled to the electric vehicle supply circuit.
54. The system of claim 53 where the power connector is a NEMA 6-50 plug.
55. The system of claim 53 where the electric vehicle supply circuit and the power connector are adapted for AC Level 2 vehicle charging.
Type: Application
Filed: Jan 11, 2010
Publication Date: Jul 14, 2011
Applicant: LEVITON MANUFACTURING CO., INC. (Melville, NY)
Inventors: Kenneth Brown (Chula Vista, CA), Carlos Ramirez (Tijuana), Manoj Karwa (Northville, MI), Erwin F. Hani (Asheville, NC), Amy Swift (Candler, NC)
Application Number: 12/685,609
International Classification: H02J 7/00 (20060101); H02H 9/08 (20060101); G01R 31/02 (20060101);