GB2597770A

GB2597770A - A method for connecting an electric plug of a power supply station with an electric socket of an electric vehicle

Info

Publication number: GB2597770A
Application number: GB2012136.4A
Authority: GB
Inventors: Ayachit Agasthya; Abdul-Hak Mohamad; Hilderbrandt Timothy; Kocher Rustam
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2022-02-09
Also published as: GB202012136D0

Abstract

The invention relates to a method for connecting an electric plug 10 of a power supply station with an electric socket 20 (Figure 2) of an electric vehicle, wherein the electric plug and the electric socket have corresponding electric contact elements 16, 18, 26, 28 configured to provide electric connection between the electric vehicle and the power supply station, wherein the electric socket comprises an electric coil 24 (Figure 2) and the electric plug comprises a magnetic member 14, the method comprising: during a charging status when the electric vehicle is charged by the power supply station, subjecting the electric coil with a first electric current thus generating a first magnetic force. According to the invention, during a non-charging status, the electric coil is subjected to a second electric current smaller than the first electric current thus generating a second magnetic force. The first connecting force may be strong enough to prevent manual disconnection. The second connecting force may be weak enough to allow manual disconnection.

Description

A METHOD FOR CONNECTING AN ELECTRIC PLUG OF A POWER SUPPLY

STATION WITH AN ELECTRIC SOCKET OF AN ELECTRIC VEHICLE

FIELD OF THE INVENTION

[0001] The invention relates to a method for connecting an electric plug of a power supply station with an electric socket of an electric vehicle, wherein the electric plug and the electric socket have corresponding electric contact elements configured to provide electric connection between the electric vehicle and the power supply station when the electric plug is connected with the electric socket, wherein the electric socket comprises at least one electric coil and the electric plug comprises at least one magnetic member, the method comprising: During a charging status when the electric vehicle is charged by the power supply station while the electric plug is connected with the electric socket, subjecting the electric coil with a first electric current, in order to provide a magnetic field acting on the magnetic member so that a first connecting force between the electric socket and the electric plug is provided.

BACKGROUND INFORMATION

[0002] Methods are known in the art, e.g. by WO 2019/075151 Al dealing with magnetically secured charging devices for electric vehicles. Usually, an electric vehicle uses electric power from a battery of the electric vehicle in order to propel the electric vehicle during a determined operation. Such vehicles, especially plug-in electric vehicles, require to charge the battery by the time. For this purpose, it is necessary to couple the electric vehicle with a power supply station or supply point, respectively. Generally, coupling is provided by connecting an electric plug of a cable of the power supply station with an electric socket arranged at the electric vehicle. This allows supplying power from the power supply station to the electric vehicle, especially to its battery.

[0003] In this regard, a user usually needs to precisely align the electric plug with the electric socket, and then apply a force to mate the plug with the electric socket. In order to maintain the electric plug connected with the electric socket, means for maintaining the connection are provided that hold the electric plug in connection with the electric socket during charging. The teaching of WO 2019/075 141 Al uses magnetic force instead of mechanic means in order to establish the means for connection.

[0004] A similar teaching is disclosed by WO 2014/003 380 Al dealing with a non-inserted charging plug for electric vehicles and charging port in non-inserted contact having the same.

[0005] Although the teaching of the above state of the art allows avoiding of mechanical means for connection, the manual operation of connecting the plug with the socket and removing the plug from the socket is still difficult. Because of safety issues, it is necessary that the magnetic force is high enough to withstand manual forces acting on the plug and the socket as well. Therefore, for providing electric connection, it is necessary that a user manually holds the electric plug very close to the electric socket and provide proper alignment of the electric plug with regard to the electric socket before activating the magnetic field. Then, the magnetic force is activated holding the electric plug with the electric socket so that there is no further need to mechanically hold the plug with the socket. The magnetic forces is high enough so that no manual force can remove the electric plug from the electric socket. Moreover, after having finished the charging process, it is necessary that the user grabs the electric plug before the magnetic force is deactivated. Otherwise, the electric plug would suddenly fall to the ground. This requires further management of activating and deactivating the magnetic force. Therefore, such a magnetic connecting mechanism is still cumbersome.

SUMMARY OF THE INVENTION

[0006] It is the object of the invention to improve operating of a magnetic connection mechanism configured to hold an electric plug connected with an electric socket based on magnetic force.

[0007] According to the invention, it is especially proposed that, during a non-charging status, the electric coil is subjected to a second electric current smaller than the first electric current so that a second connecting force between the electric socket and the electric plug is provided that is smaller than the first connecting force.

[0008] Especially, the invention is based on the discovery that it is advantageous for the connecting and disconnecting operation by the user that the connecting force generated by the magnetic field is lower than during the charging status so that the user can manipulate the electric plug such to provide a proper alignment between the electric plug and the electric socket. Therefore, the connecting force and, in response thereof, the second electric current is chosen such that, without acting of a user, the connecting force allows holding the electric plug with regard to the electric socket. However, the user can manually act on the plug in order to remove or to arrange the electric plug with regard to the electric socket in proper alignment.

[0009] During the charging status, the first current is provided so that a high connecting force can be achieved hindering the user or a robot, respectively, from removing the electric plug from the electric socket. Therefore, in the charging status, a secure connection between the electric socket and the electric plug can be achieved.

[0010] The electric socket and/or the electric plug can be any connecting means for establishing an electric connection that can be removed. The connecting means can also be referred to as electrical supply connector, electrical interface, electrical receiving connector or the like. The coil, also referred to as inductor, choke, reactor or the like, is a passive two-terminal electrical component that stores electric energy in a magnetic field depending on an electric current. Typically, the coil comprises at least one insulated electric wire being arranged in one or more turns in order to form a winding. Each of the opposing ends of the at least one electric wire is connected with a respective one of the terminals.

[0011] An electric control circuit, which is connected with the electric coil is configured to provide the first and the second electric current. For this purpose, the control circuit may be in communication with the power supply station and/or the vehicle in order to get at least one signal depending on the charging status. Also, the control circuit can have one or more electric contacts that can be manipulated by the user so that the first and/or the second electric current can be adjusted. Preferably, a value of the first and the second current may be fixed during manufacture of the electric vehicle and/or the power supply station. Preferably, the electric socket is arranged at the electric vehicle and may be protected by a lid that can be opened or removed for the purpose of charging.

[0012] The electric plug may be connected with an electric cable that itself is connected to the power supply station. The electric cable is configured to transfer electric energy from the power supply station to the electric plug so that, in the connected status, the electric vehicle, especially its battery, can be charged.

[0013] Further advantages, features, and details of the invention derive from the following description of preferred embodiment as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings show in: [0015] Fig. 1 an electric plug of a power supply station in a schematic plan view having electric contacts and magnetic members; [0016] Fig. 2 an electric socket of an electric vehicle in a schematic plan view having electric contacts and electric coils; and [0017] Fig. 3 a schematic block diagram of a circuitry for driving the electric coils.

[0018] In the figures the same elements or elements having the same function are indicated by the same reference signs.

DETAILED DESCRIPTION

[0019] Fig. 1 shows a schematic view of an electric plug 10 of a power supply station which is not shown in the figures. The electric plug 10 is connected with the electric power station via an electric cable of the electric power station. The electric plug 10 has electric contact elements 16, 18 which may establish an electric connection to respective contact elements 26, 28 of an electric socket 20 (Fig. 2) in a connected state. The contact elements 18, 28 are configured to be exerted on a high voltage. For example, high voltage comprises an electric voltage that is usually greater than then about 60 V. Preferably, the plug 10 is configured to conform to the standard ECE R 100. The contact elements 18 are provided for a high current contact. The high voltage may be DC or AC. The contact elements 16 refer to pilot-contacts which are used during the charging status in order to control the charging process.

[0020] It should be appreciated that Figs. 1 and 2 depict an exemplary embodiment of the electric plug 10 and socket 20, including contact elements 16, 18,26 and 28. As depicted in Fig. 1, pilot-contact elements 16 of the electric plug 10 may comprise two contacts (e.g. pins). In alternative embodiments, the pilot-contact elements 16 may comprise at least one contact. For example, the pilot-contact elements 16 may comprise three contacts. Similarly, as depicted in Fig. 2, the corresponding contact elements 26 of the electric socket 20 may be designed to accept two contacts. In alternative embodiments, the contact elements 26 may be designed to accept at least one contact. For example, the contact elements 26 may accept three contacts.

[0021] The plug 10 comprises a base plate 36 which is made of an electric insulating material. The base plate 36 holds the contact elements 16, 18. The base plate 36 is surrounded by an armature strip 12 which provides an outer surface that can be gripped by a hand of a user or robot.

[0022] Moreover, the armature strip 12 comprises four magnetic members 14 which are preferably made of a ferromagnetic material such as iron, nickel, cobalt, and alloys therefrom and/or the like. The magnetic members 14 are arranged in an opposing manner in the armature strip 12 around its circumference.

[0023] Fig. 2 shows the electric socket 20 of an electric vehicle in a schematic view having electric contacts 26, 28 and electric coils 24. The electric vehicle is not further depicted in the figures.

[0024] The electric plug 20 comprises the electric contacts 28 which contact the electric contacts 18 of the electric plug 10 when connected with each other. Similar, respective contact elements 26 also refer to respective pilot-contacts. The pilot-contacts 26 of the electric socket 20 mate with the contact elements 16 of the electric plug 10 in the connected status. So, in the connected status electric power and control signals can be transferred. Moreover, the electric socket 20 also comprises a baseplate 38, holding the contact elements 26, 28. The baseplate 38 is made of an electric insulating material. Additionally, the baseplate 38 is surrounded by an armature strip 22 which contains the electric coils 24. The arrangement of the electric coils 24 conforms to the arrangement of the magnetic members 14 of the electric plug 10. Therefore, in the connected status, each coil 24 opposes directly a respective one of the magnetic members 14.

[0025] Fig. 3 shows a schematic block diagram of a circuitry of the electric vehicle, especially the electric socket 20. The circuitry is provided for driving the electric coils 24. For this purpose, an energiser circuit 30 is provided which is connected with each of the electric coils 24 via an electric wiring 32 in order to expose each of the electric coils 24 to a predetermined electric current. For this purpose, the electric coils 24 can be in parallel or serial connection. Preferably, the energiser circuit 30 is supplied with electric energy from a low voltage source 34 of the electric vehicle. The low voltage source 34 can provide a DC low voltage of about 12 V or 24 V or the like. The energiser circuit 30 comprises sufficient hardware components to energise all of the electric coils 24. Moreover, the energiser circuit 30 is communicatively connected with a charge control of the electric vehicle or may be connected with the pilot-contacts 26 in order to receive information about the charging status. The energiser circuit 30 preferably has sufficient capacity to determine the charging status.

[0026] In an embodiment, the energiser circuit 30 is configured to subject each of the electric coils 24 with a first electric current during a charging status when the electric vehicle is charged by the power supply station while the plug 10 is connected with the electrical socket 20, in order to provide a magnetic field acting on the magnetic members 14 so that a first connecting force between the electric socket 20 and the electric plug 10 is provided. The first electric current is chosen such that manipulating of the plug 10 with regard to the electric socket 20 is prevented. Therefore, in this status, a secure mechanic connection between the electric plug 10 and the electric socket 20 can be achieved.

[0027] Moreover, the energiser circuit 30 is further configured to subject the electric coils 24 to a second electric current smaller than the first electric current during a non-charging status so that a second connecting force between the electric socket 20 and the electric plug 10 is provided that is smaller than the first connecting force. The second current is chosen such that a fixation between the electric plug and the electric socket 20 can be achieved but the second connecting force is weaker than the first connecting force so that a user can manipulate the electric plug 10 with regard to the electric socket 20. This status is different from the charging status because no electric power is transferred from the power supply station to the electric vehicle. Especially, the connection between the electric plug 10 and the electric socket 20 can be established or removed in this status. Further, in this status the electric contacts 16, 18, 24, 28 are not subjected to an electric voltage. Therefore, the user or a robot may operate the electric plug 10 without risking electric hazard.

[0028] Preferably, the first and the second electric current are fixedly adjusted during a manufacturing process. However, it can be provided that the first and/or the second electric current can be adjusted, e.g. by an operating personnel or the like. However, especially the value of the first electric current is chosen high enough to enable a secure mechanic connection based on magnetic force between the electric plug 10 and the electric socket 20 during the charging status when the contact elements 16, 18, 26, 28 are subjected to high voltage and are subjected to respective electric current.

[0029] Although for power transmission only two electric contacts 18, 28 are provided in the present embodiment, differing embodiments may have more electric contacts, especially if the charging voltage is not DC or single phase AC but a multi-phase AC. Moreover, the pilot-contact element 16,28 can be replaced by a wireless communication connection or the like. In this regard, a wireless interface may be integrated in the electric plug 10 and the electric socket 20.

[0030] The main objective of this invention is to develop an Electric Vehicle (EV) system for electromagnetically locking the Electric Vehicle Supply Equipment (EVSE) EV plug, a.k.a. EV connector and the EV receptacle, a.k.a EV inlet. The idea is comprised of a mechanism and an apparatus to enable the mechanism. The apparatus is an electromagnetic (EM) lock that is able to establish a secure physical connection when the EVSE EV connector is mated with the EV inlet. The mechanism can accomplish two tasks: (a) create a weak magnetic force or second magnetic force, respectively, to magnetically attract the EV connector towards the EV inlet, (b) create a strong electromagnetic force or first magnetic force, respectively, after the connection, to firmly lock the EV connector and the EV inlet together.

[0031] There are two exemplary use cases: [0032] High-power dc charging for electric passenger cars, vans, medium-and heavy-duty trucks and buses.

[0033] AC charging in private and public installations.

[0034] Robotic charging of electric vehicle -By virtue of the simplicity of the magnetic apparatus and the mechanism, the alignment between the EVSE EV connector and EV inlet is significantly improved over a more complicated and complex mechanical alignment system [0035] Working: [0036] The electromagnetic (EM) apparatus 20 would be installed on the EV inlet by the EV OEM. The EM apparatus at the EV inlet is an electronic energizer circuit 30 that emits an EM field at the magnetic strips 28 to attract the EVSE-EV connector 10. The EM field is generated by an excitation current, which further produces the attractive force required to connect with the armature firmly.

[0037] The apparatus on the EVSE-EV connector is an armature metallic strip that would mate with the EV inlet apparatus, designed by the EVSE provider in accordance with the requirements of the EV inlet apparatus.

[0038] In addition, when the EVSE-EV connector and the EV inlet are connected, the electronic circuit will strengthen the magnetic attractive force, creating a very secure and safe connection. Upon completion of charging, the EV electronic circuit is notified to weaken the EM force, enabling the user to easily disconnect the EVSE-EV connector from the EV inlet.

[0039] Design: * The EM apparatus may be able to withstand the weight of the EVSE-EV connector and to avoid a forceful unauthorized disconnection. ;* The field produced at the magnetic strips carrying the rated current is governed by the Biot-Savart's Law: py.NI The attractive force produced by the field is therefore: R2 a n 9 F - --arm 212 Ft For example: Humans can pull up to 30% their body weight. To avoid an unauthorized and forceful pull by a human weighing 75 kg, an attractive force of nearly 250 N is required. Typical EM lock magnets can generate >500 N of attractive force easily.

[0040] System benefits: 1. The magnetic lock helps prevent any tension at the EVSE-EV connector charger and EV inlet contact.

2. A consistent and repeatable alignment between the EVSE-EV connector and EV inlet is significantly improved by means of magnetic attraction.

3. Easy to integrate on any electric vehicle and any EVSE type (Level 1, Level 2, DC fast charger, mode 2, mode 3, mode 4, GBT, ac and dc).

4. Works well irrespective of environmental conditions.

5. Improves quality by replacing moving mechanical locking mechanisms with more reliable nonmoving electrical and magnetic components.

[0041] Customer benefits: No thumb press required to push a button to mechanically unlatch and extract the EVSEEV connector from the EV inlet, improving customer convenience while handling heavyweight charge cables.

1. Enhanced safety, since the apparatus can ensure the EVSE-EV connector remains locked in while the EV completes the charging process. Mechanical locking pins are possible to break by a high shear force, which would be eliminated and replaced by electrical components.

2. Lock feature can be integrated and controlled by the user through a phone app or HMI. Unwarranted unlocking is completely eliminated.

3. Due to electromagnetic attraction, the locking system would be immune to environmental conditions such as snow, dirt, and water.

[0042] The preferred and exemplary embodiments are intended to further explain the invention. Especially, it should not be regarded to limit the scope of the invention.

Reference Signs Electric plug 12 Armature strip 14 Magnetic member 16 Pilot-contact 18 Electric contact Electric socket 22 Armature strip 24 Coil 26 Pilot-contact 28 Electric contact Energiser circuit 32 Electric wiring 34 Voltage supply 36 Baseplate 38 Baseplate

Claims

CLAIMS1. A method for connecting an electric plug (10) of a power supply station with an electric socket (20) of an electric vehicle, wherein the electric plug (10) and the electric socket (20) have corresponding electric contact elements (16, 18, 26, 28) configured to provide electric connection between the electric vehicle and the power supply station when the electric plug (10) is connected with the electric socket (20), wherein the electric socket (20) comprises at least one electric coil (24) and the electric plug (10) comprises at least one magnetic member (14), the method comprising: during a charging status when the electric vehicle is charged by the power supply station while the electric plug (10) is connected with the electric socket (20), subjecting the at least one electric coil (24) with a first electric current, in order to provide a magnetic field acting on the magnetic member (14) so that a first connecting force between the electric socket (20) and the electric plug (10) is provided, characterized by during a non-charging status, subjecting the electric coil (24) to a second electric current smaller than the first electric current so that a second connecting force between the electric socket (20) and the electric plug (10) is provided that is smaller than the first connecting force.
2. The method according to claim 1, characterized in that the first electric current is selected such that the first connecting force prevents from manually removing the electric plug (10).
3. The method according to claim 1 or 2, characterized in that the second electric current is selected such that the second connecting force allows manual acting on the electric plug (10).
4. The method according to any one of claims 1 to 3, characterized in that the first current is decreased to the second current if charging of the electric vehicle is completed.
5. The method according to any one of claims 1 to 4, characterized in that the second current is increased to the first current if charging of the electric vehicle is started.