Electric vehicles (EVs) continue to grow in popularity. Accordingly, the need for EV supply equipment (EVSE) to provide charging for the EVs continues to increase. Commercial EVSEs are now located in many store parking lots and other locations. While EVs may be charged by plugging them into a standard 120V outlet, this charging may take a rather long time. Home EVSEs that provide rapid charging are now available. However, the home EVSEs require that a 240V outlet be available in an appropriate location to plug the home EVSE into the 240V outlet. Additionally, the 240V outlet requires its own breaker to be available in a breaker box for the home. An electrician is likely required to install the breaker and 240V outlet. The need to utilize an electrician increases the cost of installing the home EVSE. Furthermore, plugging an EVSE into a 240V outlet results in the charges associated with the EVSE being added to the standard electric bill.
What is desirable is an easier manner for providing home EVSEs that does not require a 240V outlet or a dedicated breaker and may not require an electrician for installation. Furthermore, it would be desirable to have an EVSE that provides insight into the amount of electricity utilized thereby and could possibly be monitored and billed separately.
The structure, objects, and advantages of an electric vehicle supply equipment (EVSE) not requiring an individual 240V outlet and corresponding breaker and also providing ability to track consumption of the EVSE separately will be understood by referring to the detailed description of illustrative embodiments in conjunction with the accompanying technical drawings, in which:
An electrical interface is a point where electricity is provided to a building (e.g., house, office building, apartment complex) from a utility company. The electrical interface may be located external to the building (e.g., on an exterior wall). The electrical interface provides the electricity to a breaker box within the building and the electricity is then distributed within the building. The electrical interface is equipped with a meter to monitor electric usage within the building (consumer usage) so the utility company can bill the consumer for their usage.
An electrical interface may be modified to provide an electric vehicle supply equipment (EVSE) therewithin. Having an EVSE located with an electrical interface (e.g., external to the building) may be desirable depending on the location of the electrical interface. Furthermore, locating the EVSE with the electrical interface eliminates the need for a 240V outlet to plug the EVSE into and the need for a specific breaker in the breaker box for the 240V outlet as the EVSE can receive the 240V at the electrical interface.
As illustrated, the charging cable 220 (and associated EV charging functionality which is not illustrated) is connected to the load (consumer) side so that the consumption of electricity thereby is captured the same as any other consumption by the consumer (by the watt hour meter 120). Alternatively, the charging cable 220 (and associated EV charging functionality) may be provided on the supply side (incoming power lines). Connecting the EV charging functionality to the supply side provides the ability to independently track the electrical consumption associated with EV charging.
The collar 410 may include a pair of current transformers 420, 422, a fused disconnect 430, an EV controller (circuit board) 440, a power relay 450, a ground fault circuit interrupter (GFCI) current transformer 460 and an EV inlet connector (e.g., J1772 connector) 470. The power from both supply lines 412, 414 is utilized to provide 240V for fast charging of the EVs. The power from the supply lines 412, 414 is provided to the EV controller 440 via the fused disconnect 430 and to appropriate pins of the EV inlet connector 470 via the fused disconnect 430 and the power relay 450. The EV controller 440 and the EV inlet connector 470 are grounded.
The fused disconnect 430 is designed to provide an external emergency switch for turning off power to the collar 410 as well as an external fuse for each of the supply lines 412, 414. It should be noted that United Laboratories (UL) requires an external manual switch to cut power in emergencies and also requires external devices (e.g., breaker, fuse) capable of cutting power in the event of an over current. The fused disconnect 430 is located external to the collar 410 and is plugged into an inlet in the collar 410. The inlet is connected to the supply lines 412, 414 so that it is powered. When the fused disconnect 430 is plugged into the inlet it becomes powered. When the fused disconnect 430 is turned to an ON position it activates a microswitch. The activation of the microswitch notifies the EV controller 440 that the switch is in an ON position so the EV controller 440 may become operational. When the fused disconnect 430 is turned to the OFF position it deactivates the microswitch. The deactivation of the microswitch means that the EV controller 440 is not notified that the switch is in an ON position so the EV controller 440 will not become operational.
The fused disconnect 430 includes a fuse therewithin associated with each of the supply lines 412, 414. When the current on a supply line 412, 414 exceeds a defined current the fuses open so the power from the supply lines is not provided to the EV controller 440 and the power relay 450. The size of the fuse utilized may vary depending on various factors including the current rating of the supply lines (jaw blades). Standard fuse sizes may be in the range of 30A-50A but are in no way intended to be limited thereby. For example, if available a 100A could be utilized without departing from the current scope. As one skilled in the art would recognize, the higher the amperage that is utilized the quicker the EV may be charged.
The current transformers 420, 422 are to measure the current (calculate the wattage) utilized for EV charging by each of the supply lines 412, 414. The current used on each line 412, 414 is provided to the EV controller 440. The EV controller 440 utilizes this information for metering the electricity used for EV charging.
An EVSE (e.g., collar 410) and an EV communicate with each other regarding the charging status via a pilot wire in an EV cable. The pilot wire is to provide information regarding, for example, whether an EV is plugged into the EV charging cable, whether charging is occurring, charging is complete, or an emergency stop is initiated. Different EVs may control the charging process in different manners. The emergency stop may be initiated by the EV and/or may be initiated by activating a button on the EV charging cable. The EV controller 440 is connected to a receptacle of the EV inlet connector 470 associated with the pilot wire (connectors of the inlet are not illustrated) via a pilot wire connection 480. Initially, the EV controller provides a constant 12V to the pilot wire while it is waiting for connectivity. When an EV is connected to the EV cable the voltage on the pilot wire drops to 9V based on a resistor within the EV. When the EV controller 440 detects this drop in voltage it initiates a charging sequence that if accepted by the EV results in another voltage drop and initiation of charging.
The GFCI current transformer 460 is utilized to determine if there are any ground fault conditions between the power relay 450 and the EV and provides that information to EV controller 440. The power relay 450 is utilized to ensure that power is provided to the EV inlet connector 470 only when appropriate. For example, power should only be provided to the EV inlet connector 470 when an EV charging cable is secured thereto, an EV is plugged into other end of the EV charging cable and the EV is ready and able to receive a charge (as discussed briefly above with respect to pilot wire). This prevents power from being provided inadvertently to, for example, a human touching the EV inlet connector 470 or the EV charging cable and/or overcharging an EV. The power relay 450 is controlled by the EV controller 440. The EV controller 440 provides a desired voltage (e.g., 12V) across the terminals of the relay 450 via connection 490 (illustrated as single line for ease of illustration but should be a line to each terminal) to activate (close) the relay 450 so that power is provided to the EV inlet connector 470. When the voltage is not provided the relay 450 is deactivated (opened) so that power is not provided to the EV inlet connector 470. According to one embodiment, the power relay 450 is a mechanical relay. Alternatively, the power relay 450 could be a solid-state relay.
The EV controller 440 may monitor and control EV charging as well as provide communications with a service provider and possibly other entities. The communications may include providing information regarding usage necessary for billing thereof and for internet of things (IoT) including maintenance. According to one embodiment, the EV charging functionality and the communications functionality are provided by components on a single board (or possibly a single integrated circuit). Alternatively, the EV charging functionality may be provided by components on one board (or IC) while the communications functionality may be provided by components on a separate board (or IC). If separate boards (or ICs) were required additional current transformer(s) may be required as each board (or IC) would need to know the current being utilized on each line (e.g., the EV charging board needs the current measurements to ensure proper operation of the EVSE and the communications board needs the current measurements for revenue tracking (billing)).
The EV controller 440 may include a DC power supply that steps down the 240V AC (+120V, −120V) received via the supply lines 412, 414 to appropriate DC voltages needed for operations. For example, the power supply may convert the 240V AC to +12V DC and −12V DC for operation of the pilot wire and possibly the relay 450. The power supply may also convert the 240V AC to +5V DC or +3.3V DC to control the components on the board (voltage being dependent on components utilized). As noted above, if separate boards are utilized for EV charging and communications, each board may require a power supply.
The meter 120 includes current transformers 122, 124 on each load line to calculate the current utilized by the customer. The current used on each line is provided to the watt hour meter 126 that tracks the power usage provided by the electrical interface 400. As the current utilized by the EVSE is tracked on the supply side it is not captured by the watt hour meter 126. Rather, the EVSE usage is captured separately.
As illustrated, the various components within the collar 410 utilized for EV charging (the EVSE) are connected to the supply side. It should be noted that if the EVSE was connected to the load side instead of the supply side that the watt hour meter 126 would track power usage of the EVSE as well as all other usage. Accordingly, billing for EV usage separately would be more complicated. The EV controller 440 may still monitor the electric usage of the EVSE separately, but the usage would already be included in the usage captured by the watt hour meter 126. Therefore, to bill separately the service provider would have to subtract the usage of the EVSE from the watt hour meter usage to get non-EV charging consumer usage. The service provider could then bill the EV usage and the non-EV usage separately. Alternatively, the service provider could monitor EVSE usage and then either bill a surcharge or provide a discount for the EVSE usage portion of the bill.
The socket end of the jaw blades 540 face the front cover 520. The front cover 520 includes a plurality of slits (not identified) that are aligned with the socket of the jaw blades 540 to allow electrical connectors from a meter 120 to pass therethrough for electrically connecting the meter 120 and the collar 500. The front cover 520 also includes a plurality of slits (not identified) to receive tabs from a meter 120 to assist in aligning the meter 120 with the collar 500 and securing the meter 120 therein.
The back cover 530 includes a plurality of tabs 532 and a plurality of slits 534. The tabs 532 are to align and help secure the collar 500 in a meter receptacle 115. The slits 534 are to enable the jaw blades 540 to pass therethrough so that they can be received by sockets of the meter receptacle 115 for electrically connecting the meter receptacle 115 and the collar 500. The housing 510 includes a powered receptacle 550 for receiving a fused disconnect 430, an opening 560 for providing access to the EV inlet connector 470 and a latch 570 for securing covers (not shown) in a closed configuration.
The receptacle 550 includes four sockets 552 (only one identified for ease of illustration) to receive an associated four tabs 432 (only one identified for ease of illustration) in the fused disconnect 430. Two of the sockets of the receptacle 550 are powered by the lines L1 and L2 (either supply or load side depending on configuration). The receptacle 550 provides the power to the fused disconnect 430 via the connection of the powered sockets 552 and the associated tabs 432. The power is provided to the fuses within the fused disconnect 430 to ensure current being drawn is not above a threshold. As long as the fuses are not tripped the power is provided to the other sockets 532 of the receptacle 550 via the associated tabs 432 of the fused disconnect 430. The receptacle 550 also includes a hole 554 for enabling a pin 434 of the fused disconnect 430 to pass therethrough. The end of the pin 434 includes a tab 436 that activates a microswitch (not illustrated) on a back end of the receptacle 550 when the fused disconnect 530 is turned to an ON position. The fused disconnect includes a handle 438 for easy rotation of the fused disconnect between an ON and OFF position.
Once the EV sees the 1 KHz square wave and interprets the duty cycle, it then introduces a second resistor to drop the voltage from +9 VDC/−12 VDC to +6 VDC/−12 VDC (or +3 VDC/−12 VDC if the battery chemistry within the EV requires ventilation). The controller detects the drop in voltage 1070 and closes the power relay to allow for Level 2 EV charging (State C) 1080. During charging the controller is running the safety checks 1090 and will terminate charge 1099 if needed due to a failed test (1095 Yes). The controller has an integrated Energy Management circuit to prevent overloading the existing service (combination of our EVSE and the pre-existing load). Our status LED, will emit a different color for each State of charge.
The untethered cable is not limited to being plugged into a specific EV charging source. As one skilled in the art would recognize, different power sources may have varying current ratings. Accordingly, plugging a lower rated untethered cable into a higher rated power source could be dangerous as it may, for example, overheat and destroy the cable. According to one embodiment, the cable includes a circuit board that is capable of measuring the duty cycle of the power provided to determine the rating of the power source. If the rating is at or below the rating of the cable, no changes are made to the power provided by the power source. However, if it is determined that the rating of the power source is higher than the rating of the cable the circuit board may reduce the rating of the power provided to the maximum rating of the cable.
The fused disconnect 430 has been disclosed with regard to being used in a meter collar providing EV charging. However, the fused disconnect is not limited thereto. Rather, the fused disconnect can be used in other types of EV charging stations. Furthermore, the fused disconnect can be used in other electrical applications where a removable fuse and a manual switch are desired.
Moreover, the fused disconnect provided the externally accessible overcurrent protection device and the manual switch that are required by UL. It should be noted that a breaker could be utilized instead of a fuse without departing from the current scope. Furthermore, a separate manual switch and externally accessible overcurrent protection device (e.g., fuse, breaker) could be utilized without departing from the current scope.
Although the invention has been illustrated by reference to specific embodiments, it will be apparent that the invention is not limited thereto as various changes and modifications may be made thereto without departing from the scope. Reference to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described therein is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment.
The various embodiments are intended to be protected broadly within the spirit and scope of the appended claims.
Number | Date | Country | |
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63315333 | Mar 2022 | US |