Plug-in charging of electric vehicles and power trailes

Abstract

The invention provides a plug-in charging of electric vehicles and electric trailers. Trailer vehicles and trailers include respective batteries and electric powertrains for propulsion. The connector system connects a vehicle and a trailer via a plurality of conductors, a plug, and a socket including at least seven connector pins. Due to the wire gauge, each conductor bears no more than 20 amperes. When a driving condition is detected, a first switch matrix in the vehicle and a second switch matrix in the trailer enter a first configuration to connect a plurality of light sources in the trailer to a lighting signal generator in the vehicle. When a charging state is detected, a second configuration of the switch matrix is entered to carry a charging current that is split in parallel between a plurality of conductors in the connector system and then recombined to provide a charging current greater than 20 amperes.

Description

Technical Field

[0001] The present invention relates generally to electrified trailers towed by electrified passenger vehicles, and more particularly to electrical couplings between such trailers and the vehicles. Background Art

[0002] The battery capacity commonly available on electric vehicles (EVs) creates challenges in providing a sufficiently long driving distance (i.e., range) before requiring recharging. In addition to providing sufficient range, it is also desirable that the time required to reach a desired state of charge be kept short when the electric vehicle is recharged.

[0003] Improvements in electrified vehicles have enabled them to be used in many types of vehicle usage applications, including towing a trailer to expand cargo capacity or for camping. The accompanying increase in weight means the electric traction motor will need to work harder to pull the trailer, resulting in greater power consumption and battery depletion (and therefore longer downtime plugged into a charger to recharge the battery pack). On average, towing an EV trailer can reduce its driving range by approximately 50%.

[0004] To help mitigate the loss of driving range, the trailer itself can be electrified. For example, an electrified trailer (ET) can carry a battery or battery pack and a drive (i.e., propulsion) system including an electric traction motor that is activated during travel to propel the ET and reduce the load requirements on the EV. The high-capacity battery and electric drive motor in the trailer can also be used to reduce the burden caused by towing a travel trailer with an internal combustion engine (ICE) vehicle.

[0005] When an EV is operated with an electric vehicle (ET), both battery systems need to be charged. Whether public or private, most charging stations are designed to accommodate a single vehicle, not a towed vehicle. Using a single charger to charge both the vehicle and trailer independently can require an undesirably long cable to be plugged into one during a first period of time, then switched to the other during a second period of time, without moving the vehicle / trailer combination. Otherwise, the driver may be required to perform difficult maneuvers to park and re-park the coupled vehicle and trailer in different locations to sequentially connect the charging cable to the vehicle and trailer.

[0006] Some trailers have been proposed whose main purpose is to carry a supplementary battery that is connected to the battery system of the main electrified vehicle to extend the driving range. In this case, a cable designed to carry high voltage and current levels is used between the supplementary battery and the main vehicle. With a high-capacity cable in place, charging can be simplified because the charging current can be shared from one of the vehicle or trailer (which is connected to the charger) to the other (which is not connected to the charger). However, such a charging scenario requires not only a high-capacity cable, but also corresponding functional components and programming to make such charging current sharing possible. Therefore, problems still exist for EVs that are not particularly well suited to sharing high levels of current with trailers.

[0007] EVs such as electrified trucks, sport utility vehicles, and recreational vehicles can typically include conventional trailer wiring for operating signal lights (such as brake lights, turn signals, and auxiliary lights), controlling the auxiliary braking system in the trailer from the main braking system, or providing a communication bus (e.g., a CAN bus) to link the trailer electronics with the towed vehicle. As used herein, a signaling-based trailer connector refers to a vehicle-to-trailer interface (such as defined in standards including SAE J2863, SAE J560, ISO 1724, and ISO 11446) that is configured for use with a voltage of no more than 24V. Common examples of connectors include Pollak-type plugs and sockets and Bargman-type connectors. The wiring sizes used with signaling-based trailer connectors are typically in the range of 16 gauge to 12 gauge, which is much smaller than the wire sizes used to share battery charge to provide propulsion or for recharging the battery. For example, individual conductors in a typical signaling-based trailer connector may be limited to approximately 20 amps, while Level 2 charging for electrified vehicles (the most commonly installed type of EV battery charger) supports up to 80 amps. Summary of the Invention

[0008] In one aspect of the present invention, a device for interconnecting a towed vehicle and a trailer is provided. The towed vehicle and the trailer each include a corresponding battery and a corresponding electric powertrain for propulsion during a driving state. The device includes a first switch matrix in the towed vehicle and a second switch matrix in the trailer. A connector system includes a plurality of conductors, a plug, and a socket, wherein at least seven connector pins in the plug and the socket interconnect the first switch matrix and the second switch matrix via a plurality of conductors. A controller is configured to invoke a first connection state within the first switch matrix and the second switch matrix during a driving state so that a lighting signal from the towed vehicle is coupled to a signal light on the trailer via the connector system. The controller is configured to invoke a second connection state within the first switch matrix and the second switch matrix when the towed vehicle and the trailer are not in a driving state so that a current suitable for charging one of the corresponding batteries is carried in parallel through at least two of the plurality of conductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of an electrified vehicle towing two trailers carrying secondary battery units arranged in series.

[0010] Figure 2 Schematic diagram of an electric trailer connected to an electric vehicle via a small trailer lighting plug.

[0011] Figure 3 An overhead view of a charging station layout with drive-through lanes to accommodate longer vehicles.

[0012] Figure 4 This is a diagram of the trailer plug and socket wiring that interconnects the switching circuits of the electric trailer and the electric vehicle.

[0013] Figure 5 is a wiring diagram showing the redistribution of the various wires when in charging mode.

[0014] Figure 6 is a block diagram showing the electrified trailer and the electrified vehicle in more detail.

[0015] Figure 7 is a flow chart illustrating a preferred method of the present invention. DETAILED DESCRIPTION

[0016] Figure 1An electrified vehicle 10 configured as an electric pickup truck is shown (which may be a battery electric vehicle, or BEV, or a hybrid gas-electric vehicle). Vehicle 10 has an onboard rechargeable battery unit 11 that stores electricity used by a traction motor (not shown) to propel vehicle 10. The traction motor may include an electric motor mechanically coupled to a gearbox, which may include a differential. The electric motor may also act as a generator during deceleration, recovering energy that would normally be lost as heat in the friction braking system.

[0017] The battery unit 11 can be composed of multiple cells that provide a high-voltage direct current (DC) output. The contactor module can optionally connect the battery unit 11 to a high-voltage bus (not shown). The power electronics module (not shown) controls the operation of the motor and provides the ability to transfer energy bidirectionally between the battery unit 11 and the motor. The power electronics module can convert the DC voltage into a three-phase AC current to operate the motor. In regenerative mode, the power electronics module can convert the three-phase AC current from the motor acting as a generator into a DC voltage for recharging the battery unit 11.

[0018] The vehicle 10 is configured to recharge the battery unit 11 from an external power source (i.e., a battery charger) using one or more charging ports 12 and 13. The external power source may include a power outlet in a private or public place. The electric vehicle supply equipment (EVSE) for connecting to the charging port of the vehicle may include a charger unit at a charging station (i.e., a location with a parking space or space, each of which is provided with one or more charger units). Charging stations serving multiple electrified cars and trucks can be connected to a distribution network or grid provided by an electric utility company and can be managed by an electronic control system, enabling users to reserve time periods and charger outlets for their use, as described in patent application publication US2020 / 0148068A1 and patent US11,001,161, both of which are incorporated herein by reference.

[0019] The trailer 14 is an electric trailer having a battery unit 15 and an electric motor (not shown) for independently propelling the trailer 14 to match the forward or rearward propulsion of the vehicle 10, so that the presence of the trailer 14 does not prematurely deplete the state of charge (SOC) of the battery unit 11 in the vehicle 10. The trailer 14 may include one or more charging ports 17 and 18 configured to deliver charging current from an external battery charger to recharge the battery unit 15. The trailer hitch system 16 couples the vehicle 10 and the trailer 14 in a towing arrangement that includes a mechanical linkage and an electrical connection. Specifically, the trailer hitch system 16 may be of a type designed to provide electrical connections for conventional trailer functions such as operating trailer signal lighting (e.g., parking lights, turn signals, or running lights), transmitting control signals to trailer-mounted brakes, coupling a low-current supplemental DC voltage for other trailer accessories, or transmitting electronic bus communication signals. Furthermore, trailer hitch system 16 may lack any wiring or other components to support the transfer of battery charging current between vehicle 10 and trailer 14. Thus, battery unit 11 may only be recharged using charging ports 12 and 13 located on vehicle 10, and battery unit 15 may only be recharged using charging ports 17 and 18 located on trailer 14.

[0020] Figure 2 The vehicle 10 and trailer 14 are shown in more detail. A connector system 21 electrically couples the towed vehicle 10 and the electrified trailer 14. The signaling-based trailer connector includes a plug 22 carried by the trailer 14 and a receptacle 23 mounted on the vehicle 10. A plurality of pin arrangements 24 and a plurality of conductors 25 transmit electrical signals and have a configuration (e.g., wire size and material) to support lighting and communication signals with currents up to approximately 20 amps. A branch 26 directs the electrical signals through other trailer wiring to a plurality of light sources 20A-20D and a trailer brake unit 27. On the vehicle side, a wiring harness H connects the receptacle 23 to a control module 19 and other vehicle electronics as known in the art. The control module 19 can generate the voltage / current required to drive the light sources 20A-20D, or a separate driver can be utilized. In the embodiment of the invention described below, a power manager / voltage controller can also be connected to the wiring harness H and the receptacle 23 for battery charging.

[0021] exist Figure 2 In the embodiment shown, trailer 14 is of a known type that includes an independent propulsion device, wherein power from battery 15 is applied to electrical load 28. Load 28 may include a traction motor, an inverter, and a motor controller for propelling trailer 14 to follow the movement of vehicle 10. Power manager 29 is coupled between charging port 17 and battery unit 15 to perform conventional charging when connected to an external battery charger.

[0022] Figure 3A pass-through layout of a charging station 30 is shown having charging receptacles 31-33 disposed adjacent to multiple pass-through lanes 34-37. In a charging station with this layout, a vehicle 10 and trailer 14 combination can be parked so that the towed vehicle 10 and trailer 14 can be recharged simultaneously, for example, by connecting them to separate chargers 31 and 32. However, such a pass-through arrangement may be uncommon for public charging stations. Additionally, the availability of multiple chargers and charger placement (or length of power cables) for reaching both the vehicle and trailer simultaneously may be unlikely at a residential installation. It is desirable to recharge both the towed vehicle and the electrified trailer while remaining in a single parking location and using only a single charger / cable pulled into a single charging port of the combined vehicle and trailer.

[0023] Figure 4 is a schematic diagram of an embodiment of the present invention in which a standard signaling-based trailer connector has a plug 40 and a socket 41. In a common 7-wire arrangement, the pins and wiring conductors associated with the plug 40 and the socket 41 define a plurality of conductor paths 42, including a ground wire 43, a brake control wire 44, a taillight wire 45, an auxiliary power wire 46, a left turn / brake light wire 47, a right turn / brake light wire 48, and a reverse light wire 49. A switch matrix 50 in the vehicle and a switch matrix 51 in the trailer are connected to the socket 41 and the plug 40, respectively, so as to employ the conductor paths 42 for the following dual purposes: (1) normal driving operation during driving conditions, and (2) providing multiple parallel current paths for dividing the charging current into smaller current portions, thereby enabling the delivery of a total charging current greater than the individual ratings of any of the conductor paths in the trailer connector. The matrices 50 and 51 may preferably be composed of, for example, electronic controller relay switches. In a first connection state of matrices 50 and 51, selected during a driving state, the individual switches in the matrices interconnect lighting signals from a control system 52 in the towed vehicle to conventional trailer wiring leading to signal lights on the trailer. In a second connection state of matrices 50 and 51, invoked during a battery charging state, the individual relay switches interconnect conductor paths 42 to a power source and battery system 53 in the vehicle and a power source and battery system 54 in the trailer, such that current suitable for charging one of the respective batteries is carried in parallel through at least two of the plurality of conductor wires 43-49.

[0024] Figure 5An example of redistributing conductor wires according to wire pairings to each conduct a corresponding portion of current through a connection system is shown. The current portions can then be recombined in a recipient's power / battery system in a vehicle or trailer. Depending on the relative sizes of the actual wire gauges available, one or more wires can be provided to carry the positive side of the corresponding portion of current, while one or more wires can be provided to carry the ground side of the corresponding portion of current. Figure 5 A one-to-one correspondence of wires in each portion of the current is shown. Thus, wires 43 and 44 carry the first portion C1 of the current, wires 45 and 46 carry the second portion C2 of the current, and wires 47 and 48 carry the third portion C3 of the current. For example, if each of the current portions C1, C2, and C3 is limited to 20 amps each by wire gauge size, the current portions can be recombined at the receiving end to provide a battery charging current of up to 60 amps.

[0025] Figure 6 An embodiment of the present invention is shown with an electrified vehicle (EV) side and an electrified trailer (ET) side. Connectors 40 and 41 of the connector system interconnect the vehicle and trailer between switch matrices 50 and 51. Matrices 50 and 51 are shown as relays, which connect multiple conductors through corresponding connectors to carry a set of driving signals (during the driving state) or a set of charging signals (during the battery charging state). On the EV side, relay 50 is connected to a power manager / voltage controller 60, which interfaces with the battery pack 11 and the charging port 12. Controller 25 is connected to power manager / voltage controller 60 and the charging port 12 to operate the charging function in a known manner. Controller 25 is connected to relay 50 to select between the configurations of the various switches in relay 50 to connect connector 41 to the light signal / trailer brake signal source during the driving state or to the battery charging signal source (to or from the vehicle) during the charging state. Controller 25 is also connected to a memory 61 containing a specification database for identifying wire gauge sizes based on the identification or classification of the particular trailer present. Identification can be performed based on an identification signal sent from the trailer via the connector system to the controller 25 or based on other identification means (e.g., capturing an image of the trailer for analysis or by manual input from a user of the vehicle). For manual input, a human machine interface (HMI) 62 is provided. Alternatively, user input can be obtained via a wireless connection through a wireless transceiver 63 for communicating with a mobile device carried by the user. The HMI 62 and / or a mobile application on the mobile device can also provide an interface for specifying charging parameters for the distribution of charging current when in charging mode, as described below.

[0026] Controller 25 is coupled to relay 50 to select between the first or second switching configurations, as well as to supply vehicle lighting signals during the driving state. Controller 25 interfaces with power manager / voltage controller 60 to appropriately configure the respective portions of the charging current during the charging state and distribute the current portions to the respective inputs of relay 50, such that the current portions are coupled in parallel to the different conductors of the connector system. The parallel currents can then be recombined in the trailer after being directed to power manager / controller 66 in the trailer via relay 51.

[0027] The trailer also includes a controller 64 for controlling the operation of the power manager / voltage controller 66 and selecting between the first and second configurations of the relay 51 (i.e., to direct signals between the connector system and the light source and auxiliary brake unit 65 or the power manager / voltage controller 66). The charging port 17 on the trailer side is also coupled to the controller 64 and the power manager / voltage controller 66, wherein the controller 64 can detect the charging status on the trailer side and can initiate the transmission of charging signals to the vehicle via the connector system.

[0028] Figure 7 A preferred method of the present invention is shown in which a check is performed in step 70 to determine if the vehicle / trailer is in driving mode. Driving mode can be triggered when the vehicle driveline is activated, when the vehicle is in gear, or in response to any other vehicle state inconsistent with vehicle charging. When driving mode is detected, the relay is set for trailer driving in step 71. The configuration of the relay connects the lighting signal generator in the vehicle to the light source in the trailer (i.e., each of the conductors in the connector system functions according to its standard trailer signaling and / or braking function). When not in driving mode, a check is performed in step 72 to determine if the vehicle / trailer is in charging mode. For example, charging mode can be detected when the charging port becomes active. If charging mode is not detected, return to step 70 for further monitoring.

[0029] When the charging port is active in step 72, any charge sharing requirements between the battery cells of the vehicle and trailer are determined in step 73 (e.g., whether one battery or both batteries need to be charged). Preferably, the user is given the ability to determine various charging parameters, such as specifying the order of charging (vehicle or trailer first) or specifying a target charge level for at least one of the battery cells. The user can choose to charge both batteries simultaneously. Alternatively, the user can specify to initially charge one of the battery cells to an initial target level, then subsequently charge the other battery cell to another target level, and then return to charge the first battery cell to yet another target level (e.g., fully charged).

[0030] Based on the selected charge sharing and the corresponding wire gauge sizes present in the connector system, the current portions are distributed among the corresponding wires in the connector system in step 74. In step 75, the power manager and relays are configured according to the current distribution from step 74. After the relays and power manager are configured, the charging current is obtained from the charging port and distributed according to the distribution. In step 76, the current and charge levels are monitored, and the current is adjusted as needed when various target levels are reached.

Claims

1. An apparatus for interconnecting a towed vehicle and a trailer, wherein the towed vehicle and the trailer each include a respective battery and a respective electric powertrain for propulsion during a driving state, the apparatus comprising: a first switch matrix in the towed vehicle; a second switch matrix in the trailer; a connector system comprising a plurality of conductors, a plug, and a socket, wherein at least seven connector pins in the plug and the socket interconnect the first switch matrix and the second switch matrix via the plurality of conductors; as well as A controller is configured to invoke a first connection state within the first switch matrix and the second switch matrix during the driving state so that a lighting signal from the towing vehicle is coupled to a signal light on the trailer via the connector system, and is configured to invoke a second connection state within the first switch matrix and the second switch matrix when the towing vehicle and the trailer are not in the driving state so that a current suitable for charging one of the corresponding batteries is carried in parallel through at least two of the plurality of conductors.

2. The apparatus of claim 1 , further comprising a current regulator configured to direct a plurality of parallel currents to respective ones of the plurality of conductors, wherein each respective parallel current is limited to a respective predetermined maximum current capacity of each respective conductor based on its respective wire gauge.

3. The apparatus of claim 2 , wherein the controller is configured to (1) determine an identification of at least one of the towing vehicle or the trailer, and (2) obtain the corresponding predetermined maximum current capacity of the corresponding conductor in a specification database based on the identification.

4. The apparatus of claim 1 , wherein at least one of the towed vehicle and the trailer has a charging port adapted to connect to an external battery charger, and wherein not being in the driving state is detected in response to the charging port being coupled to the external battery charger.

5. The apparatus of claim 1 , wherein the battery receiving the current suitable for charging is in one of the towed vehicle or the trailer, and wherein the other of the towed vehicle or the trailer includes a charging port adapted to connect to an external charger to generate the current suitable for charging.

6. The apparatus of claim 1, wherein the controller is responsive to a user selection designating charge sharing between the towed vehicle and the trailer.

7. The apparatus of claim 6, wherein the specified charge sharing includes a charging sequence or target charge levels of at least one of the respective batteries in the towed vehicle and the trailer.

8. A method of interconnecting a towed vehicle and a trailer, wherein the towed vehicle and the trailer each include a respective battery and a respective electric powertrain for propulsion, wherein the towed vehicle and the trailer are electrically connected via a connector system including a plurality of conductors, a plug, and a receptacle, wherein the plug and the receptacle include at least seven connector pins, wherein the connector pins and corresponding conductors are configured to carry no more than 20 amperes, the method comprising the steps of: detecting the driving status of the towing vehicle and the trailer; When in the driving state, configuring the first switch matrix in the towing vehicle and the second switch matrix in the trailer in a first configuration to interconnect the connector system between the plurality of light sources in the trailer to the lighting signal generator in the towing vehicle; detecting a charging status of the towing vehicle or the trailer; as well as When in the charging state, the first switch matrix in the towed vehicle and the second switch matrix in the trailer are configured in a second configuration to carry a current suitable for charging one of the corresponding batteries in parallel through at least two of the plurality of conductors in the connector system.

9. The method of claim 8, further comprising the steps of: A plurality of respective parallel currents are directed to the respective conductors, wherein each respective parallel current is limited to a respective predetermined maximum current capacity of each respective conductor according to its respective wire gauge.

10. The method according to claim 9, further comprising the steps of: determining an identification of at least one of the towed vehicle or the trailer; as well as The corresponding predetermined maximum current capacity of the corresponding conductor is obtained from a specification database according to the identification.

11. The method of claim 8, wherein at least one of the tow vehicle and the trailer has a charging port adapted to connect to an external battery charger, and wherein the charging status is detected in response to the charging port being coupled to the external battery charger.

12. The method of claim 8, wherein the battery receiving the current suitable for the charging is in one of the towed vehicle or the trailer, and wherein the other of the towed vehicle or the trailer includes a charging port suitable for connecting to an external charger to generate the current suitable for the charging.

13. The method of claim 8, further comprising the steps of: A user specifies charge sharing between the towing vehicle and the trailer.

14. The method of claim 13, wherein the specified charge sharing includes a charging sequence or target charge levels of at least one of the respective batteries in the towed vehicle and the trailer.

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