WO2016177598A1

WO2016177598A1 - Plug connector part comprising a temperature-dependent switching device

Info

Publication number: WO2016177598A1
Application number: PCT/EP2016/059212
Authority: WO
Inventors: Markus Rose
Original assignee: Phoenix Contact E-Mobility Gmbh
Priority date: 2015-05-06
Filing date: 2016-04-26
Publication date: 2016-11-10
Also published as: DE102015107053A1

Abstract

A plug connector part (4A, 4B) for connection to a mating plug connector part (10, 20) comprises at least one electrical power contact element (42A-42E) for transmitting a useful current between the plug connector part (4A, 4B) and the mating plug connector part (10, 20), a signal contact element (42F) for transmitting a control signal between the plug connector part (4A, 4B) and the mating plug connector part (10, 20), and a signal line (43F) which is connected to the signal contact element (42F). A switching device (44) is also provided, said switching device being designed to electrically disconnect the at least one signal contact element (42F) from the signal line (43F) depending on heating which occurs at the plug connector part (4A, 4B).

Description

Connector part with a temperature-dependent switching device

The invention relates to a connector part for connection to a mating connector part according to the preamble of claim 1.

A connector part for connecting to a mating connector part comprises at least one electric power contact element for transmitting a useful current between the connector part and the mating connector part, a signal contact element for transmitting a control signal between the connector part and the mating connector part, and a signal line connected to the signal contact element.

Such a connector part can in particular be used on a charging device for transmitting a charging current. The connector part can be designed, in particular, as a charging plug or charging socket for charging an electric motor-driven motor vehicle (also referred to as an electric vehicle).

Charging plugs and charging sockets for charging electric vehicles are to be designed so that large charging currents can be transmitted. Because the thermal power dissipation increases quadratically with the charging current, at least such charging plugs and charging sockets transmitting a charging current in the form of a direct current, it is necessary to provide a temperature monitor to detect overheating on components of the charging plug or the charging socket early and possibly a modification the charging current or even a shutdown of the charging device to effect.

In a charging plug known, for example, from EP 2 605 339 A1, a temperature sensor is arranged on an insulating body approximately in the middle between contact elements of the contact plug. It can be detected via the temperature sensor whether there is excessive heating somewhere on the contact elements, in order to possibly switch off the charging process.

US Pat. No. 8,325,454 B2 discloses a plug in which individual contacts are assigned thermistors which are connected in parallel with one another and, when a threshold temperature is exceeded, turn on a thyristor in order to switch off a current flow through the contacts in this way. In general, in a connector part, for example a charging plug or a charging socket, the contact resistance between the power contact elements and the associated contact elements of the mating connector part should be as low as possible. If the contact resistance is low, the risk of an (inadmissible) temperature increase at the power contact elements is low. For example, a permissible temperature increase may be limited to 50 Kelvin.

However, in particular in the case of dirt or damage to the power contact elements, it can lead to an increase in the contact resistance and, consequently, an impermissible temperature increase in the region of the power contacts. In order to reduce the risk of damage to the connector part in this case, a temperature monitoring using temperature sensors is prescribed in DC charging systems. For AC charging systems, ie for charging systems in which charging takes place by means of a charging current in the form of an alternating current, such regulations do not currently exist. As alternating current formed charging currents are generally smaller than charging currents in the form of direct current.

However, it may be desirable to provide a temperature monitoring even with AC charging systems. However, this can be particularly difficult with charging cables, because in a charging cable control lines can not be readily provided, because this would require a complex adaptation of the charging system (including the charging station and the circuits in the vehicle). Object of the present invention is to provide a connector part, in which a temperature control for influencing a charging current can be made in a simple manner, without that connected to the connector part, higher-level systems would have to be elaborately modified. This object is achieved by an article having the features of claim 1.

Accordingly, the connector part has a switching device which is designed to electrically disconnect the at least one signal contact element as a function of a heating occurring at the connector part from the signal line.

The present invention is based on the idea to use a temperature-dependent switching device, but not (directly) on the Power contact elements acts, but changed a switching state on the signal contact element. The switching device is temperature-dependent and switches as a function of a heating occurring at the connector part, for example one of the electrical power contact elements. In this case, the switching device switches from a state in which the signal contact element is connected to the assigned signal line into a disconnecting state in which the signal contact element is disconnected from the signal line.

Because the switching device does not act directly on the one or more power contact elements, the switching device need not be designed to transmit large currents either. About the signal contact element flow only in their amount low signaling currents. A switching device for switching such currents is available inexpensively and can be simple. The switching of the signal contact element makes an evaluation possible, which can then lead to influencing, in particular for reducing or switching off the charging current. If the connector part is designed, for example, as a charging connector of a charging cable, a suitable control device can be provided, for example, at a charging station or a vehicle, which recognizes that the electrical connection via the signal contact element is interrupted in order then to switch off the charging current and thus interrupt a charging process.

The connector part can be realized for example as a charging connector on a charging cable or as a charging socket, for example, on a vehicle or at a charging station. In principle, however, another use outside of a charging system is conceivable and possible.

For the purposes of the present invention, it is thus provided to generate a status signal by switching the signal contact element as a function of an occurring heating, which can be evaluated in order to influence a current flow via the power contact elements, in particular to switch it off.

A switching device that can be used for this purpose is available at low cost. Further, elaborate modifications to the connector part or the overall parent system are not required. An evaluation of the switching state of the signal contact element can in a simple, software-controlled manner be performed in an already existing control unit of the entire system, for example in a charging station or a vehicle.

The switching device may in particular be designed to disconnect the signal contact element from the signal line when a predetermined threshold temperature at the switching device is exceeded. The switching device can for example be arranged directly in the region of the power contact elements in order to receive a temperature increase at the power contact elements. For example, it is conceivable that the switching device is embedded in an insulating body, on which the power contact elements are arranged. It is also conceivable that the switching device is thermally coupled to the power contact elements via thermally conductive elements, such as metallic traces of a printed circuit board. Such a connector part can be used in particular in a system in which a useful current is transmitted in the form of an alternating current. For example, the connector part can be used on a charging cable, which is to transmit a charging current in the form of a direct current from a charging station to a vehicle.

Different embodiments of a switching device are conceivable and possible. For example, the switching device can be designed as a reversibly switchable device, ie as a switching device that can be switched between different states back and forth. However, it is also conceivable and possible for the switching device to be designed as an irreversibly switchable device in which switching for disconnecting the signal contact element from the signal line is thus possible, but not switching back from the disconnecting state to a connecting state.

In a specific embodiment, the switching device may be formed for example by a bimetallic switch. In such a bimetal switch, a bimetallic strip in the form of a composite of two metals with different coefficients of thermal expansion is temperature-dependent bendable. When the temperature increases, the bimetallic strip changes its shape and in this way can interrupt an electrical connection between the signal line and the signal contact element. In another embodiment, the switching device can also be realized by an electronic switching device, so an electronic module with a temperature sensor and its own evaluation for switching. With a temperature increase, a switch can then be activated in order to electrically separate the signal contact element from the signal line.

In yet another embodiment, the switching device can also be realized by a thermal fuse. Such a thermal fuse is in particular irreversibly switchable by, for example, in a connecting state, a contact bridge electrically connects line sections to one another and is electrically connected to these line sections via fusible link connections. When the temperature increases, the solder melts and the contact bridge is separated from the line sections, so that an electrical connection between the signal contact element and the signal line is electrically separated.

As thermal fuses other security elements can be used, which work with bimetals, PTC thermistors or with a low-melting metal.

In yet another embodiment, the switching device may also be formed by a temperature switch with liquid. For example, the liquid may be in a hermetically sealed vessel. When the temperature rises, the liquid evaporates, so that a so-called pressure cell is actuated and switches a switching contact over it. Such a connector part may in particular be part of a charging cable for charging an electric vehicle. The power contact elements in this case are connected to line conductors for transmitting a (large) charging current. The signal contact element, however, is connected to a signal line of the charging cable and is used for transmitting a signaling signal. Such a charging cable, for example, each have a connector part at two ends, which can be inserted on the one hand in a mating connector part of a charging station and on the other hand in a mating connector part of a vehicle. Each of these connector parts may have a switching device of the type described above, and it is also conceivable and possible that only one of the connector parts comprises such a switching device. In an arrangement of a connector part and a mating connector part, a control device is advantageously provided, which is for example part of the mating connector part or a higher-level system, whose part is the mating connector part. The mating connector part can be arranged for example on the side of a charging station or a vehicle. In this case, the control device may be part of the charging station or the vehicle, for example. The control device serves to switch off a charging current flowing via the one or more power contact elements when the signal contact element is separated from the signal line by means of the switching device. The control device thus serves to evaluate a switching state of the signal contact element and, depending on this, optionally to switch off a charging current which flows via the power contact elements.

Whether the signal contact element is electrically connected to the signal line can be evaluated by the control device in a simple manner. For example, it may be provided that a signal in the form of a square-wave voltage is transmitted via the signal line from a charging station to a vehicle, which indicates which charging power is available. If the control device determines that the square-wave signal is not present on the side of the vehicle, this indicates that the connection between the signal contact element and the signal line within the connector part has been disconnected.

Of course, other, easier evaluations are possible. For example, the input impedance can be picked up at the signal contact element. If an open circuit is detected on the signal contact element, this likewise indicates the electrical separation of the signal contact element from the signal line.

The idea underlying the invention will be explained in more detail with reference to the embodiments illustrated in the figures. Show it:

Figure 1 is a schematic view of an electric vehicle with a charging device connected thereto.

Fig. 2A is a perspective view of a connector part with a

Temperature sensor means;

FIG. 2B is a front view of the connector part of FIG. 2A; FIG. 3 is a schematic view of a charging cable with connector parts arranged thereon; and FIG. 4 is a schematic view of a connector part of the charging cable in FIG

Cooperation with an associated mating connector part.

Fig. 1 shows a schematic view of a vehicle 1 in the form of an electric motor driven vehicle (hereinafter referred to as electric vehicle). The electric vehicle 1 has electrically rechargeable batteries, via which an electric motor for moving the vehicle 1 can be electrically supplied.

In order to charge the batteries of the vehicle 1, the vehicle 1 can be connected to a charging station 2 via a charging cable 3. The charging cable 3 can be inserted with a connector part 4 at one end in an associated charging socket 10 of the vehicle 1 and is at its other end with a suitable charging socket 20 to the charging station 2 in electrical connection. Charging currents with comparatively high current intensity are transmitted to the vehicle 1 via the charging cable 3.

An embodiment of a connector part 4 in the form of a charging connector, Figs. 2A and 2B. The connector part 4 comprises a housing 40 with a plug-in portion 401, which can be brought into engagement with the associated charging socket 10 on the vehicle 1 (see FIG. 1). Longitudinally extending contact elements 42A-42G protrude into the plug-in section 401 along a plug-in direction E, which are arranged on a bottom 400 of the housing 40 and can be plugged into the plug-in direction E in a manner known per se with associated contact pins of the charging socket 10. Of the contact elements 42A-42G, the contact elements 42B-42E arranged along a semicircle around the central contact element 42A serve as so-called power contacts for transmitting the (large) charging currents. Accordingly, overheating may occur, in particular, at these contact elements 42B-42E, if, for example, the resistance increases locally due to, for example, a material defect or a defect, and thus a large amount of thermal power is released locally. Among the power contact elements 42A-42E, the contact elements 42B-42D may serve as outer conductor contacts (also referred to as "LT," L2 "and" L3 "), while the contact element 42D may be referred to as neutral (also referred to as the letter" N ") and the centrally arranged contact element 42A serve as a protective contact (also referred to as "PE"). These power contact elements 42A-42E are used to transmit a charging current in the form of a single- or multi-phase, for example, three-phase alternating current having an effective value of, for example, between 50 and 100 amperes and a voltage of, for example, between 400 and 600 volts. The additional contact elements 42F, 42G, however, serve the signaling. Thus, contact element 42F represents a signal contact element (also referred to as a "control pilot", in short "CP"), via which signaling information can be transmitted. The contact element 42G, on the other hand, serves as a so-called proximity contact (also referred to as a "proximity pilot", in short "PP").

For example, a square-wave voltage can be transmitted via the signal contact element 42F, by means of which information about a maximum available charging power can be transmitted from the side of the charging station 2 to the vehicle 1. For example, the charging station 2 can impress a 1 kHz square-wave voltage, which can be received on the side of the vehicle 1, for example via a resistor, via a 1 kΩ resistor between the signal contact element 42F and the protective contact-providing power contact element 42A. Information about the maximum available power on the side of the charging station 2 can be transmitted by means of pulse width modulation via this square-wave voltage.

By contrast, the proximity contact 42G can detect the presence of a connector part 4A, 4B on an associated mating connector part 10, 20 on the side of the charging station 2 or of the vehicle 1.

The connector parts 4A, 4B are part of the charging cable 3. Herein, as shown schematically in Fig. 3, the power contact elements 42A-42E via line wires 43A-43E connected to each other. During a charging process, large charging currents are transmitted from the charging station 2 to the vehicle 1 via these line conductors 43A-43E. The signal contact elements 42F of the connector parts 4A, 4B, however, are connected to each other via a signal line 43F, and the Proximity contacts 42G of the connector parts 4A, 4B are connected to each other via a line conductor 43G.

In order to carry out a temperature monitoring in such a charging cable 3 and in particular to counteract damage in the form of a temperature increase at one of the connector parts 4A, 4B of the charging cable 3, the signal contact elements 42F of the connector parts 4A, 4B are each assigned temperature-dependent switching devices 44, via which the signal contact elements 42F the signal line 43F are connected.

The temperature-dependent switching device 44 may be configured for example by a bimetal switch, an electronic switch (using a suitable temperature sensor) or a thermal fuse or the like. If a temperature is detected at the temperature-dependent switching device 44 which is above a temperature threshold, then the switching device 44 switches and in this way disconnects the associated signal contact element 42F from the signal line 43F. The electrical connection between the signal contact elements 42f of the connector parts 4A, 4B is canceled in this way. The electrical disconnection of the connection between the signal contact elements 42F can be detected on the side of the charging station 2 or of the vehicle 1. By way of example, the impedance at a signal contact element 42F can be picked up at the connector part 4B assigned to the charging station 2 or at the connector part 4A assigned to the vehicle 1. Or it can be detected on the side of the vehicle 1 that a square-wave voltage impressed by the charging station 2 is not received on the side of the vehicle 1.

For this purpose, for example on the side of the vehicle 1, a control device 5 may be provided, as shown schematically in Fig. 4. By means of the control device 5 it can be evaluated whether the electrical connection between the signal contact element 42F and the signal line 43F has been interrupted by means of the switching device 44.

If this is the case, then the control device 5 can initiate suitable countermeasures and, in particular, switch off a charging current flowing via the power contact elements 42A-42E, so that a (further) temperature increase at the connector part 4A, 4B is ruled out. For example, the switching device 44 may be thermally coupled to the power contact elements 42A-42E by having thermally well conductive elements conducting heat from the power contact elements 42A-42E to the switching device 44, or the switching device 44 disposed in close spatial relationship with power contact elements 42A-42E.

The switching device 44 may be formed by a low-cost component, which only has to be designed for switching low currents. In particular, no large current flows through the signal line 43F during operation, so that the switching device 44 can be of simple construction.

By means of the switching device 44, the charging currents via the power contact elements 42A-42E are thus not directly influenced and switched off, but indirectly, by a control device 5, a switching state on the signal contact element 42F of the connector part 4A, 4B is evaluated and switched based on information derived from the charging current, especially switched off, is. Such a control device 5 is already present, for example, on the side of the charging station 2 or the vehicle 1, so that no costly conversion in the system is required for this purpose.

Basically, the charging socket 10 on the side of the vehicle 1 and / or the charging socket 20 on the side of the charging station 2 may have a switching device 44 of the type described above. This is e.g. makes sense if the control device 5 on the side of the vehicle 1 or a control device on the side of the charging station 2 are not designed for the evaluation of a temperature sensor (because this example, does not have enough sensor inputs).

The idea underlying the invention is not limited to the embodiments described above, but can in principle also be realized in a completely different kind of way.

In particular, a connector part of the type described here is not necessarily limited to use on charging systems, in particular for charging electric vehicles, but can also be used in other applications. The mating face of the connector part can be configured as desired and comprises at least one power contact element and a signal contact element. It is conceivable and possible that the connector part comprises, for example, power contact elements for transmitting an alternating current and also power contact elements for transmitting a direct current. One or more signal contact elements may be provided, wherein a temperature monitoring of the type described on one or more signal contact elements can be made.

LIST OF REFERENCE NUMBERS

1 vehicle

10 charging socket

2 charging station

20 charging socket

3 charging cables

4A, 4B connector part

40 housing

400 floor

401 plug-in section

41 housing room

42A-42G contact element (contact socket)

43A-43G conductor

44 Temperature-dependent switching device

5 control device

E insertion direction

Claims

claims

1 . Connector part (4A, 4B) for connection to a mating connector part (10, 20), with

- At least one electrical power contact element (42A-42E) for

Transmitting a useful current between the connector part (4A, 4B) and the mating connector part (10, 20),

a signal contact element (42F) for transmitting a control signal between the connector part (4A, 4B) and the mating connector part (10, 20) and

a signal line (43F) connected to the at least one signal contact element (42F),

characterized by switch means (44) adapted to electrically disconnect the at least one signal contact element (42F) from the signal line (43F) in response to a heating occurring at the connector part (4A, 4B).

Second connector part (4A, 4B) according to claim 1, characterized in that the switching device (44) is formed when a predetermined threshold temperature at the switching device (44) is exceeded, the signal contact element (42F) to be separated from the signal line (43F).

3. connector part (4A, 4B) according to claim 1 or 2, characterized in that the Nutzstrom is an alternating current.

4. connector part (4A, 4B) according to one of claims 1 to 3, characterized in that the switching device (44) is formed by a bimetallic switch.

5. connector part (4A, 4B) according to one of claims 1 to 3, characterized in that the switching device (44) is formed by an electronic switching device.

6. connector part (4A, 4B) according to one of claims 1 to 3, characterized in that the switching device (44) is formed by a thermal fuse.

7. connector part (4A, 4B) according to one of claims 1 to 3, characterized in that the switching device (44) is formed by a temperature switch with liquid.

8. charging cable (3) with at least one connector part (4A, 4B) according to one of the preceding claims.

9. Arrangement with a connector part (4A, 4B) according to one of the preceding claims and a mating connector part (10, 20), characterized by a control device (5) for switching off over the at least one

Power contact element (42A-42E) flowing charging current when the signal contact element (42F) by means of the switching device (44) is separated from the signal line (43F).