CHARGING STATION PROVIDING THERMAL CONDITIONING OF ELECTRIC VEHICLE DURING CHARGING SESSION
A vehicle includes an energy storage configured to store electric energy for at least propulsion of the vehicle, an energy storage thermal system configured to provide thermal conditioning of the energy storage, and a coupling configured to receive thermal conditioning of the energy storage from a thermal system external to the vehicle. The coupling provides thermal conditioning of the energy storage while charging when available from the thermal system external to the vehicle. The energy storage thermal system provides thermal conditioning of the energy storage while charging when the thermal system external to the vehicle is not available.
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The present U.S. Utility Patent Application claims priority pursuant to 35 U.S.C. §120 as a continuation of U.S. Utility application Ser. No. 14/264,364, entitled “CHARGING STATION PROVIDING THERMAL CONDITIONING OF ELECTRIC VEHICLE DURING CHARGING SESSION,” filed Apr. 29, 2014, issuing as U.S. Pat. No. 9,527,403 on Dec. 27, 2016, which is hereby incorporated herein by reference in its entirety and made part of the present U.S. Utility Patent Application for all purposes.
BACKGROUNDElectric vehicles depend on being recharged with electric energy at regular intervals. Energy storages in such vehicles (e.g., lithium-ion battery packs) typically accept direct current (DC) power for recharging. Some charging stations provide a supply of DC that typically plugs into the vehicle by way of a cable. Some electric vehicles have onboard chargers that convert alternating current (AC) to DC and these vehicles can therefore accept a supply of AC, such as from an outlet in the vehicle owner's home or at another location.
Battery packs generate heat during use, both when charging and when power is being drawn from the cells (e.g., to power an electric motor). For this reason, battery packs typically have some form of cooling system. In the case of electric vehicles, this is an onboard cooling system that removes heat from the battery pack (e.g., by way of a coolant loop in between the cells). The removed heat is then generally released into the atmosphere, for example by way of a radiator, a condenser, and/or a chiller.
This document describes examples of systems and techniques that provide thermal conditioning of an electric vehicle during a charging session. For example, the charging of an electric vehicle can generate significant heat in the battery pack (especially in a fast charging mode), and external cooling can then be provided to maintain the battery pack within an acceptable temperature range during the charging session. As another example, some charging procedures may require the battery pack to initially have at least a minimum temperature, and an external system for warming the battery pack can then be provided. Also, as charging rates increase, the cooling needs during charging will exceed the cooling needs during driving, which means off board cooling becomes more advantageous. For simplicity, the following description sometimes uses the term “coolant” to describe a fluid that is circulated through a system to provide thermal conditioning, with the understanding that such a fluid can be used to either extract thermal energy from the system (i.e., cool the system) or add thermal energy to the system (i.e., heat the system), depending on the circumstances.
The vehicle generates thermal information 130 that reflects the current need for thermal conditioning of the vehicle's energy storage (e.g., battery pack). The vehicle's energy storage can be configured so that it communicates the temperature of coolant that it needs at a given moment. That is, the energy storage can determine its own need for thermal conditioning and then specify a corresponding temperature value. In situations where the external thermal conditioning system 100 is not present (e.g., while the vehicle is being driven), this thermal information can trigger the vehicle's onboard cooling system to supply coolant of an appropriate temperature.
On the other hand, when the external thermal conditioning system 100 is available to the vehicle (e.g., at a charging station), the thermal information can also (or instead) be provided to the external thermal conditioning system, which can then use that information in providing thermal conditioning. For example, the electric vehicle power system 110 can generate a wireless transmission for receipt by the external thermal conditioning system 100. The communication can be transmitted using any suitable standard or protocol, including, but not limited to, via Bluetooth.
Some implementations can use a signaling protocol as follows. An initial signal from the vehicle to the charging station is transmitted by wireless communication (e.g., Bluetooth), and this serves to couple the vehicle to the charging station. In response, the appropriate vehicle-charger connections can be established, including an electrical connection for the charging (and, in some implementations, a fluid connection for thermally conditioning the vehicle during the charging). Then, a temperature demand signal or any other form of thermal information can be sent to the charging station via a signal wire in the electrical connector.
The external thermal conditioning system receives the communication generated by the vehicle and responds to it by providing the appropriate thermal conditioning (e.g., by way of supplying coolant at the specified temperature). In some implementations, the external thermal conditioning system can use a specified temperature value in choosing between available thermal modes. For example, the external thermal conditioning system 100 selects between at least a cooling mode and a heating mode based on the thermal information. External thermal conditioning can be provided as shown with two spate reservoirs and flow streams, or with heating and cooling elements interacting with a single flow stream, or through any standard thermal regulation methodology.
The thermal conditioning can be provided during as much or as little of the charging session as necessary or desired. In some situations, the thermal conditioning can occur solely before any electric energy is fed into the vehicle (e.g., if the battery pack needs to be heated before charging begins). In other situations, the thermal conditioning can begin after some amount of charging has been performed (e.g., to counteract rising heat in the battery pack). In other situations, the thermal conditioning can be performed during the entire charging session.
The internal cooling system 202 serves to thermally condition the battery pack 208 during operation of the vehicle 204. Here, the internal cooling system includes one or more cooling tubes 212 in thermal contact with the cells of the battery pack 208, a heat exchanger 214 where heat from the coolant is released into the air, a reservoir 216 that holds some of the circulating coolant, and at least one pump 218 that circulates the coolant through the internal cooling system. While the vehicle is being driven, the internal cooling system can continuously remove heat generated by the cells in the battery pack, and by other parts of the vehicle's powertrain (e.g., the electric motor) in order to keep the components at an appropriate working temperature.
The external thermal conditioning system 200 can be coupled to the vehicle 204 by a connector 220. For example, this can be a quick-disconnect fluid coupling. The connector couples a port 222A to an inlet 224A of the heat exchanger 206, and couples a port 222B to an outlet 224B of the heat exchanger. That is, the connector allows fluid to flow between the external thermal conditioning system and the heat exchanger, which in turn is in thermal contact with the coolant of the internal cooling system 202. Here, the connector 220 represents only a connection for fluid between the vehicle and the external system, but in some implementations, a common connector can provide separate connections for fluid and electricity to the vehicle. Such a common connector can also have one or more signal wires to facilitate communication between the vehicle and the charging station. For example, the vehicle can use the signal wire to send thermal information to the charging station for the charging session.
The external thermal conditioning system 200 has a line 226 for circulation of the external coolant. A hot reservoir 228 and a cold reservoir 230 are selectively coupled to the line by respective valves 232A-B (e.g., three-way valves). At least one pump 234 is provided to circulate coolant in the line 226 as needed. The external thermal conditioning system is controlled by a controller 236. For example, the controller can detect whether the connector 220 is currently attached (by way of a sensor on the connector), open the valve 232A or B (or both) to feed coolant into the line, and run the pump to circulate the coolant. A controller can be used in any of the examples described herein (e.g., to receive the thermal information from the vehicle and choose an appropriate thermal conditioning in response), but is not always explicitly shown or discussed for brevity.
In operation, the connector 220 is coupled to the vehicle 204, such as by operation of an automated arm positioned underneath the vehicle. For example, this coupling is done at a charging station where the vehicle is currently being charged, or in preparation for such charging of the vehicle. The internal cooling system 202 can be running at this point, or it can currently be inactive.
A connection 238 can be established between the vehicle 204 and the external thermal conditioning system 200. In some implementations, the BMS 210 generates thermal information about the battery pack 208 and the vehicle then transmits that information as a message over the established connection. For example, a wireless signal can be transmitted, directly or indirectly, for receipt by the controller 236.
The external thermal conditioning system 100 receives the thermal information from the battery pack through the connection 238, and chooses an appropriate thermal mode based on it. Thereafter, the external system begins circulating coolant in the line 226, including through the heat exchanger 206, according to the selected thermal mode. For example, the heat exchanger 206 is a liquid-to-liquid heat exchanger where the coolant from the external system and the coolant of the internal system are in thermal contact with each other, such as by flowing across plates or other surfaces. That is, in this example the external system removes heat from the internal system in order to manage the temperature of the battery pack during charging. In such scenarios, the external system can draw fluid predominantly from the cold reservoir 230 so as to provide the appropriate cooling in the heat exchanger. In other cases, the external system can provide warmer fluid (i.e., from the hot reservoir 228) so as to heat the coolant of the internal system and thereby bring the battery pack up to a temperature suitable for a type of charging that is about to be initiated.
The reservoirs 228 and 230 are maintained within suitable predefined temperature ranges. For example, heating elements can be provided inside or on the outside of the hot reservoir so as to keep the fluid at the correct temperature. This includes re-heating the fluid after some of it is used in heating one or more battery packs. In some implementations, the hot reservoir is active only in those time periods when battery packs are expected to need heating (such as during winter).
The cold reservoir 230, in turn, has one or more cooling units to keep the coolant at a specified temperature. Similarly, after or during cooling of one or more battery packs, the cold reservoir can be actively chilled so as to maintain the temperature.
The sizes of the hot and cold reservoirs 228 and 230 are selected based on the expected amount of thermal conditioning they should provide. For example, the two reservoirs 228 and 230 can be installed to serve a charging station that has multiple (e.g., ten) charging spots, and a certain number of vehicles is expected to use the station every day, so the reservoir capacity will be chosen accordingly. Also, the geographical location of the charging station will influence such considerations, in that a hot climate will likely create a demand for cooling all year-round (with perhaps no need for heating), and a cooler climate will need heating and cooling during different seasons.
Some implementations can use another way of regulating the temperature of the external coolant than, or in addition to, the hot and cold reservoirs 228 and 230. For example, an electrical inline heater can be used for heating the flowing coolant. As another example, an inline direct refrigerant cooler can be applied to chill the coolant.
The arm 400 and its associated components are here located in a well 410 that is at least partially below ground surface. For example, this can be part of the underground system 300 (
The fluid connector 402 is coupled to fluid lines 412 and the electric connector 404 is coupled to electric lines 414. The fluid lines (e.g., flexible tubes) are part of an external thermal conditioning system that circulates coolant to and from the fluid connector. The electric lines (e.g., flexible conduits) are part of an external charging system that provides electric energy for charging an electric vehicle.
In other implementations, the arm 400 and the associated components that control it can instead serve as a pure charging system. For example, the fluid connector 402 and the fluid lines 412 can be omitted or inactive, and the arm can be used to automatically and conveniently charge electric vehicles.
In operation, the arm 400 is positioned with regard to the fluid connector 504 and the electric connector 506 by way of a spatial guiding system. In some implementations, a laser guiding system can be used. For example, the arm can have mounted thereon a light detector and a lens or other optics that provides a laser beam. The reflections of the laser beam from the structures underneath the vehicle (e.g., the connectors 504-06) can then be detected as a way of properly orienting the arm into the correct position for establishing the connection. In some implementations, a camera mounted on or near the arm can capture images of the vehicle underbody, and based on the image capture, the arm can automatically be guided to the correct position. As another example, the camera view can be presented to a human operator who can remotely control the movement of the arm. In other implementations, one or more other approaches for automatic guiding can instead or additionally be used, including, but not limited to: infrared illumination, mechanical locators (e.g., tapered pins), ultraviolet illumination, radar scanning, or optical guidance.
In some implementations, coupling the fluid connector 402 to the fluid connector 504 does not involve tapping into the vehicle's internal cooling system. Rather, the coupling serves to bring the external coolant into a liquid-to-liquid heat exchanger in the vehicle, which heat exchanger in turn provides a thermal interface to the vehicle's internal cooling system. That way, the external coolant can perform thermal conditioning of the internal coolant (and thereby of the battery pack 502) without one having to open (and then close) the internal cooling system to the outside.
In other implementations (e.g., as described below), the coupling of the fluid connector 402 to the fluid connector 504 does provide fluid exchange between the internal and external cooling systems. For example, this allows the external system to draw existing coolant out from the internal system and replace it with properly tempered coolant from an external reservoir.
The external thermal conditioning system 700 can be implemented at least partially underground. For example, the external system can be part of the underground system 310 (
The external thermal conditioning system 700 can include the reservoirs 228 and 230, the line 226 and the pump 234, substantially as previously described. In other implementations, another way of thermally conditioning the external coolant can also or instead be used, including, but not limited to, inline electric heating.
The external thermal conditioning system 700 is operated by a controller which is here omitted for clarity. In operation, the pump circulates fluid of an appropriate temperature (based on thermal information from the vehicle 708) through the line 226 and into conductive pads 710 from which the thermal contactors 702 extend. The conductive pads are configured to provide good thermal exchange between the coolant and the thermal contactors so as to allow the latter to withdraw heat from, or add it to, the energy storage system 706. For example, the conductive pads can be made from metal, or a composite or other synthetic material.
The conductive pads 710 can be actuated in at least a vertical direction by scissor lifts 712. For example, after the vehicle is correctly positioned, the scissor lifts can be activated to advance the conductive pads upward, thereby passing the thermal contactors through the openings 704 into their designated places. In other implementations, the conductive pads can be maneuvered by an actuated arm, such as the arm 400 shown in
The external thermal conditioning system 800 can be implemented at least partially underground. For example, the external system can be part of the underground system 310 (
The external thermal conditioning system 800 here has a tube 814 or other conduit through which air flows, driven by at least one blower 816. The air in the tube is brought to a proper temperature by being acted on by either a heater 818 or a chiller 820. For example, the external cooling system can receive thermal information (e.g., a specified temperature value) from the vehicle 808 can heat or cool the circulated air as needed. The circulating air is fed into the air inlet 802, which can have a manifold that distributes the air into multiple flows depending on the number of openings 804 on the battery pack. The pressure of air flowing into the battery pack can drive air out through the openings 810 and into the air outlet 812, which can have a manifold that joins multiple air flows into one. The openings 810 can have the same number and/or sizes as the openings 804. From the air outlet, the air can pass through a filter 822 to remove dust or other contaminants, and thereafter continue circulating in the tube 816. That is, the external cooling system 800 can supplement, or act in lieu of, the vehicle's internal cooling system 202, while the vehicle is at a charging station to be charged.
In other implementations, the air outlet 812 can be omitted, instead allowing the air leaving the battery pack to escape into the ambience. The filter 822 can then instead have an air inlet that draws in ambient air, with the blower 816 pushing that air past the running heater or chiller, as applicable, and then into the battery pack.
The external thermal conditioning system 1000 uses the pump 234 to force coolant drawn from the hot reservoir 228 and/or the cold reservoir 230 into a sprayer manifold 1004 configured to direct an array of the jets 1002 toward the underside of the energy storage 208. In other implementations, another way of thermally conditioning the external coolant can also or instead be used, including, but not limited to, inline electric heating.
In some implementations, the sprayer manifold can be moved during while spraying coolant onto the battery pack, for example so as to direct the jets 1002 at different areas of the battery pack. The sprayer manifold can be as wide as, or narrower than, the battery pack. The sprayer manifold can be as long as, or shorter than, the battery pack.
A waste water collector 1006 can be positioned underneath the battery pack so as to collect the sprayed coolant. For example, the coolant can be filtered before being recirculated in the external thermal conditioning system.
The external thermal conditioning system 1000 can be implemented at least partially underground. For example, the external system can be part of the underground system 310 (
In other implementations, the jets 1002 can also or instead be directed at another component of the vehicle. For example, the jet can be directed at a heat exchanger (e.g., a radiator, condenser, and/or cold plate) that is part of an internal cooling system of the vehicle.
The external thermal conditioning system 1100 vertically positions the conductive pad 1102 using one or more scissor lifts 1104. The external thermal conditioning system 1100 uses the pump 234 to force coolant drawn from the hot reservoir 228 and/or the cold reservoir 230 into the conductive pad, which is configured to contact the underside of the energy storage 208 (e.g., a base plate that forms the bottom of the battery pack). In other implementations, another way of thermally conditioning the external coolant can also or instead be used, including, but not limited to, inline electric heating.
The physical pressure between the conductive pad 1102 and the energy storage 208 will be maintained at an appropriate level. For example, the pressure must not be so high that the conductive pad damages the outer casing of the battery pack. The conductive pad can be as wide as, or narrower than, the battery pack. The conductive pad can be as long as, or shorter than, the battery pack.
The external thermal conditioning system 1100 can be implemented at least partially underground. For example, the external system can be part of the underground system 310 (
The external thermal conditioning system 1200 uses the pump 234 to circulate coolant in the line 226, including to and from the connector 220. Here, the coolant is drawn from the hot reservoir 228 and/or the cold reservoir 230. In other implementations, another way of thermally conditioning the external coolant can also or instead be used, including, but not limited to, inline electric heating.
Inside the vehicle 1202, an inlet 1204A of the cooling tube 212 receives the coolant from the connector 220 (i.e., from the external system 1200) and allows it to enter the internal cooling system 202. A corresponding outlet 1204B of the cooling tube 212 allows coolant to flow out of the internal cooling system and into the external system. The internal cooling system 202 can have a check-valve 1206 to stop reversed coolant flow in the cooling tube 212.
The external thermal conditioning system 1200 can be implemented at least partially underground. For example, the external system can be part of the underground system 310 (
The contoured vehicle guides 1304 can help properly position the vehicle above the underground system 310. The contoured vehicle guides are raised above the ground surface and have a funnel shape that directs the vehicle into the correct position and indicates where to stop. For example, the vehicle guides on the respective sides of the charging spot can each have a curve 1306 that provides rolling resistance for the vehicle's front wheels if the vehicle is off to one side, or when the vehicle has pulled sufficiently far into the spot. The contoured vehicle guides can be made from any material of sufficient durability against the wear of vehicle wheels and the exposure to weather. For example, concrete can be used.
A number of implementations have been described as examples. Nevertheless, other implementations are covered by the following claims.
Claims
1. A vehicle comprising:
- an energy storage configured to store electric energy for at least propulsion of the vehicle;
- an energy storage thermal system configured to provide thermal conditioning of the energy storage; and
- a coupling configured to receive thermal conditioning of the energy storage from a thermal system external to the vehicle,
- wherein the coupling provides thermal conditioning of the energy storage while charging when available from the thermal system external to the vehicle; and
- wherein the energy storage thermal system provides thermal conditioning of the energy storage while charging when the thermal system external to the vehicle is not available.
Type: Application
Filed: Dec 16, 2016
Publication Date: Apr 6, 2017
Applicant: Tesla Motors, Inc. (Palo Alto, CA)
Inventors: Joseph Mardall (San Francisco, CA), Christopher H. Van Dyke (San Francisco, CA)
Application Number: 15/381,259