EP3549150B1 - Device for separating an electrical system from an energy source - Google Patents

Description

The invention relates to a device for disconnecting a direct voltage (on-board) network from an energy source or an energy store, and a method for disconnecting a voltage supply or an energy store from a direct voltage network.

In the prior art, there are a wide variety of embodiments of isolating devices for interrupting direct current between a DC power source and an electrical device or load known.

Since such a DC voltage source must be safely and reliably disconnected from the on-board network under certain conditions in the vehicle, on the other hand, disconnection must not take place during driving. In this respect, a corresponding disconnecting device must be able to interrupt an interruption under load, i.e. H. without switching off the DC power source beforehand.

For load separation z. B. a mechanical switch (switching contact) can be used with the advantage that when the contact has opened, a galvanic separation of the electrical device from the direct current source is established. The disadvantage, however, is that such mechanical switching contacts are worn out very quickly due to the arc that occurs when the contact is opened, or that additional effort is required to enclose and cool the arc, which is usually done by a corresponding mechanical switch with an arcing chamber.

If, on the other hand, powerful semiconductor switches are used to disconnect the load from the vehicle electrical system, unavoidable power losses also occur in the semiconductors during normal operation. In addition, with such power semiconductors no galvanic separation and thus no reliable personal protection are ensured.

From the WO 2010/108565 A1 a disconnection device with a mechanical switch is known, which in the non-triggered state of the disconnection device is live. Semiconductor electronics are connected in parallel to the mechanical switch and are connected to the mechanical switch in such a way that when the mechanical switch opens, the current flow through the isolating device is interrupted due to an arc forming in the area of the mechanical switch.

Furthermore, the DE 101 16 925 C1 a motor vehicle with a voltage network between an energy store and a generator with a rectifier, a safety-relevant control device connected to the voltage network both activating an auxiliary actuated actuator and supplying it with power, with the current flow between connections of the safety-relevant control device at one pole of the energy store and at one Corresponding output of the generator, an electrical battery isolator is arranged. The control device is designed in such a way that it retains a residual voltage in order to actuate an electromotive actuator accordingly in an emergency driving program.

A prerequisite for electrically operated motor vehicles, especially in test operation, is that they can be de-energized via a so-called battery isolating switch. This is to prevent the current from increasing a hazard potential, for example through sparks that can be caused by the power supply, which could possibly result in fires or explosions.

On the other hand, it is necessary for safe driving that certain units remain functional until the motor vehicle is parked and that they are not disconnected during driving.

Up to now, the loads to be separated known in the prior art were comparatively low, so that various technical problems, such as arc ignition, contact safety, etc. could be controlled or only occurred to a minor extent. In the present case, DC loads are to be switched at 12V and 48V, with currents of up to 1,500 A. In such load assumptions, it should be ensured that a defined number of, for example, 15 switching cycles can be implemented.

For example, a known technical isolating device or a circuit breaker can switch DC loads up to 100 A if necessary. B. a number of e.g. 50,000 switching cycles can be achieved. However, such known devices no longer show any effective switching behavior at currents of 500 A and more, since the device can only implement a single switching process, if at all. However, if the aforementioned high loads are to be switched reliably, the devices known from the prior art fail.

If two real contacts of a switch move towards each other, the dielectric strength of the existing air gap is below a certain minimum distance. The amount of the minimum distance depends on the prevailing field strength and thus on the voltage potential between the switching contacts. As a result, a spark or a so-called pre-ignition arc can occur above the minimum voltage and current. This stresses the contact surfaces (Contact erosion), it may melt and can lead to contact welding. Such damaged switches can no longer be opened. At the moment of contact, the rules of impact mechanics apply: elastic and plastic deformation of the contact surfaces occurs with the consequence of possible lift-offs, the effect of bouncing. The contacts hit together and briefly spring apart again, so that additional interference pulses can arise. When a mechanical switch is opened, the contact force initially decreases and the metallic contact surfaces become smaller. This increases the electrical resistance, the contact point heats up and the contact material melts, especially with higher currents. If the connecting material bridge breaks, an arc will form, ie the air will be ionized. There are very high power losses, which lead to the melting and evaporation of contact material.

Consequently, a solution is required for a device for separating which satisfactorily solves the aforementioned problem.

Thus, the solutions known in the prior art are furthermore unsuitable for satisfactorily or at all solving the various other objectives that are pursued with this invention.

It is desirable that the device can be used universally and can therefore be used as a separate assembly at the desired vehicle position. This also necessitates the requirement that, depending on the installation position, a splash-proof and possibly shock-proof design is required.

Furthermore, the high-current switch should be designed to be bistable, ie it should also function in the currentless state.

Furthermore, incorrect operation or incorrect signals must be reliably detected and these must not lead to an undesired switching process. The design must also be redundant and controllable via a controller.

From the WO 2014/023326 A1 a disconnecting device is already known which is suitable for repeatedly disconnecting a load greater than 12 KW.

The invention is based on the object of overcoming the aforementioned disadvantages in the prior art and of specifying a particularly suitable disconnection device for interrupting direct current in the high load range between a direct current source and an electrical device or load of 15kW.

This object is achieved by the combinations of features according to claim 1 and claim 12.

According to the invention, a disconnection device is accordingly provided which is designed to repeatedly disconnect a load greater than 12 KW of a 12V or 48V direct voltage (on-board) network from an energy store, preferably an energy store of a motor vehicle, consisting of a base and an insulating housing, with the housing inside a special switching arrangement is provided which enables safe closing and, above all, disconnection of the load path.

The invention can also be used with other nominal voltages VDC and currents, as well as in applications outside a vehicle in which high direct current loads have to be switched.

The circuit is preferably designed compactly in a circumferentially closed housing and a first energy storage connection and a second energy storage connection protrude from the housing. Furthermore, a first electrical switching path S1 is between a bistable Relay and a first signal line protruding from the housing for connection to a mechanical actuator, such as a changeover switch or button. According to the invention, a second electrical switching path S2 is also provided between the bistable relay and a second signal line protruding from the housing for connecting to an actuator, such as a mechanical changeover switch or a button, with a stable switching state of the bistable relay optionally via one or the other Switching path can be produced by actuating with the actuator, whereby at least two two-dimensional switching contact pairs of the relay are brought into a contacting position or simultaneously into a spaced apart position, i.e. the distance between the contact pairs is preferably the same in the separated position.

In a preferred embodiment of the invention it is provided that the switching contact pairs of the relay are designed as cylindrical, end-face flat contacts (similar to a tablet shape) with an essentially circular end contact surface.

It is furthermore advantageously provided that the contacting or disconnection of the switching contact pairs takes place by changing the position of a symmetrically constructed switching rocker, which is connected to a permanently magnetic armature rocker. An embodiment is particularly advantageous in which the load path has a course as follows: from a static contact of the relay initially to a mating contact (first contact pair) movable on the contact rocker via an essentially Z-shaped rocker arrangement to the second contact on the contact rocker to the static mating contact (second pair of contacts).

In a further advantageous embodiment of the invention it is provided that four contact pairs are provided, which consist of contacts preferably formed at symmetrically arranged positions on the contact rocker and the respective corresponding positions of the mating contact elements.

In a further advantageous embodiment of the invention it is provided that a protective device is provided in each of the first and second switching paths, which prevent bouncing and overload in the relay when the relay is switched. For this purpose, it can be provided that the protective device comprises a debouncing device, preferably a low-pass filter or a hardware-based locking logic.

Furthermore, in a preferred embodiment it is provided that the respective protective device also has a semiconductor switching component, preferably a MOSFET, whose gate is connected to one of the signal lines and whose drain-source path is arranged in the respective switching path.

In a further advantageous embodiment of the invention it is provided that the first energy storage connection is directly connected to at least one contact (preferably a static contact) of the switching contact pairs and / or the second energy storage connection is or are directly connected to another contact of the other switching contact pairs .

It is further preferred if the two energy storage connections each protrude through the respective housing wall on diametrically opposite side walls of the housing (11) and are designed as essentially flat connection tongues with a connection opening, these being linear or around a bending point upwards at an angle of Bent away by approx. 90 ° protrude from the housing.

A particularly compact design is achieved in this way.

Furthermore, it is advantageously provided that in the housing of the separating device a line bushing is provided on a frontal housing wall which connects the two housing walls and through which the signal lines protrude. In this way, a freely configurable separating device can be implemented, in particular in that the line lengths and designs can be adapted accordingly to the respective application.

It can also be provided that the lines led out of the separating device are connected to a plug connector, so that simple assembly on site is possible without the need for field assembly.

It is particularly advantageous if the switching paths are connected to an a- or bistable toggle switch or a button by means of the signal lines. In this way, the load circuit can be safely separated from the location where the actuator is attached.

It is further preferred if a control is also provided via which an operating state of the vehicle can be called up and the control prevents or allows separation by means of the separating device depending on the detected operating state.

Another aspect of the invention relates to an on-board power supply with direct current loads of more than 12 KW, preferably in a motor vehicle, equipped with a separating device as described above, the separating device being connected to at least one energy storage device via its energy storage connections.

Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures.

Fig. 1a - 1d

mehrere Ansichten eines Ausführungsbeispiels einer erfindungsgemäßen Trennvorrichtung;

Fig. 2

eine schematische Darstellung einer Schaltungsanordnung einer erfindungsgemäßen Trennvorrichtung und

Fig. 3

eine Detailansicht des bistabilen Relais der Schaltung aus Figur 2.

Show it:

Figures 1a-1d

several views of an embodiment of a separating device according to the invention;

Fig. 2

a schematic representation of a circuit arrangement of a separating device according to the invention and

Fig. 3

a detailed view of the bistable relay of the circuit Figure 2 .

In the following, the invention will be explained using a merely exemplary embodiment with reference to FIG Figures 1a - 1d, 2 and 3 explained in more detail, the same reference numbers indicating the same functional and / or structural features.

In the Figures 1a to 1d several views of an embodiment of a separating device 1 according to the invention are shown. The separating device 1 is used to separate (at least 15 times) a load greater than 12 KW with a switching current of up to 1500 A in a DC voltage network.

The separating device 1 consists of a base 10 and an insulating housing 11, which in the present case is circumferentially closed, wherein within the housing 11, the in Figure 2 Switching arrangement 20 shown is provided. The housing 11 has a first side wall 11a and a diametrically opposite side wall 11b. The separating device 1 further comprises the two energy storage connections 31, 41, each on the diametrically opposite side walls 11a, 11b of the housing 11 protrude through the respective housing wall.

The energy storage connections 31, 41 are designed as essentially flat connection tongues with a connection opening 31a, 41a in order to connect them to an energy storage.

In the housing 11 of the separating device 1, a line bushing 12 is also provided on a frontal housing wall 11c that connects the two housing walls 11a, 11b and through which signal lines 32, 42 protrude. The length of the signal lines 32, 42 can vary depending on requirements.

In the Fig. 2 a schematic diagram of a circuit arrangement 20 is shown. The circuit arrangement 20 comprises, on the one hand, a bistable relay 50.

A first electrical switching path S1 is provided between the bistable relay 50 and a first signal line 32 which protrudes from the housing 11 and is connected to a button 33 in this exemplary embodiment. Furthermore, a second electrical switching path S2 is provided between the bistable relay 50 and a second signal line 42 which protrudes from the housing 11 and is connected to the button 43.

A respectively stable switching state of the bistable relay 50 can then be produced optionally via one or the other switching path S1, S2 by pressing the respective button 33, 43, whereby at least two of the in the Figure 3 shown, two-dimensional switching contact pairs 55a, 55b and 56a, 56b of the relay 50 are each brought simultaneously into a contacting or spaced-apart position.

In the Figure 2 it can also be seen that in the first and second switching path S1, S2 each have a protective device 34, 44 which prevent bouncing and overload in the relay 50 when the relay is switched.

The protective devices 34, 44 include a low-pass filter 36, 46 and each a semiconductor switching component, preferably a MOSFET 37, 47, the gate G of which is connected to one of the signal lines 32, 42 and the drain-source path RDS in the respective switching path S1, S2 is arranged, which leads to the relay 50 in order to switch the relay 50 can.

In Figure 3 FIG. 3 is a detailed view of the bistable relay 50 of the circuit 20 from FIG Figure 2 shown. The two pairs of switching contacts 55a, 55b and 56a, 56b of the relay 50 are designed as cylindrical contacts 55, 56 which are flat on the end face and have a substantially circular end contact surface 55c, 56c. The contacting or disconnection of the switching contact pairs 55a, 55b and 56a, 56b is carried out by a switching pulse triggered by one of the buttons 33, 43 by changing the position of a symmetrically constructed switching rocker 54, which is connected to a permanent magnet armature rocker 58, which is dependent on the switching pulse of one of the buttons 33 , 43 changes to its open or closed position.

The first energy storage connection 31 is directly connected to the static contact of the two switching contact pairs 55a, 55b. The second energy storage connection 41 is directly connected to the further static contact, namely the other pair of switching contacts 56a, 56b.

In the Figure 2 a controller 60 is also provided, via which an operating status (e.g. the status of the ignition, driving status and the like) of the vehicle can be called up and the controller 60 is dependent on the detected operating status e.g. B. vehicle is, a separation by means of the separating device 1 allows or z. B. Ignition on and vehicle in Driving operation, a separation by means of the separating device 1 is prevented.

Claims (12)

1. A disconnecting device (1) designed for multiple disconnections of a load greater than 12 KW of a DC voltage vehicle electrical system from an energy accumulator (2) of a motor vehicle consisting of a base (10) and an insulating housing (11), wherein a switching arrangement (20) is provided inside the housing (11) and a first energy accumulator terminal (31) and a second energy accumulator terminal (41) protrude from the housing (11), wherein furthermore a first electrical switching path (S1) between a bi-stable relay (50) and a first signal line (32) protruding out of the housing (11) for connection to a mechanical toggle switch or a pushbutton (33) and a second electrical switching path (S2) between the bi-stable relay (50) and a second signal line (42) protruding out of the housing (11) for connection to the mechanical toggle switch or a pushbutton (43) are provided, wherein furthermore a respective stable switching state of the bi-stable relay (50) is alternately producible via the one or the other switching path (S1, S2) by actuating a switch or pushbutton (33), whereby at least two flatly formed switching contact pairs (55a, 55b and 56a, 56b) of the relay (50) are each simultaneously brought into a contacting position or a position spaced apart from one another.
2. The disconnecting device (1) as claimed in claim 1, characterized in that the switching contact pairs (55a, 55b and 56a, 56b) of the relay (50) are formed as cylindrical contacts (55, 56) flat on the end face having an essentially circular end contact face (55c, 56c).
3. The disconnecting device (1) as claimed in claim 1 or 2, characterized in that the contacting or disconnecting of the switching contact pairs (55a, 55b and 56a, 56b) is performed by means of position change of a symmetrically constructed rocker switch (54), which is connected to a permanent-magnetic armature rocker (58).
4. The disconnecting device (1) as claimed in claim 1, 2, or 3, characterized in that a protective device (34, 44), which prevents bouncing an overload in the relay (50) during the switching of the relay, is provided in each case in the first and second switching path (S1, S2).
5. The disconnecting device (1) as claimed in claim 4, characterized in that the protective device (34, 44) comprises a debouncing unit, preferably a low-pass filter or a hardware interlocking logic.
6. The disconnecting device (1) as claimed in claim 4 or 5, characterized in that the respective protective device (34, 44) furthermore respectively has a semiconductor switching component, preferably a MOSFET, the gate (G) of which is connected to one of the signal lines (32, 42) in each case, and the drain-source route (RDS) of which is arranged in the respective switching path (S1, S2).
7. The disconnecting device (1) as claimed in any one of the preceding claims, characterized in that the first energy accumulator terminal (31) is directly connected to a contact of the two switching contact pairs (55a, 55b and 56a, 56b) and/or the second energy accumulator terminal (41) is directly connected to a contact of the other switching contact pair (55a, 55b and 56a, 56b).
8. The disconnecting device (1) as claimed in any one of the preceding claims, characterized in that the two energy accumulator terminals (31, 41) each protrude on diametrically opposing side walls (11a, 11b) of the housing (11) through the respective housing wall (11a, 11b) and/or are formed as essentially flat terminal tongues having a terminal opening (31a, 41a).
9. The disconnecting device (1) as claimed in any one of the preceding claims, characterized in that in the housing (11) of the disconnecting device, it has a line feedthrough (12) on a frontal housing wall (11c) connecting the two housing walls (11a, 11b), through which the signal lines (32, 42) protrude.
10. The disconnecting device (1) as claimed in any one of the preceding claims, characterized in that the switching paths (S1, S2) are connected by means of the signal lines (32, 42) to an a-stable or bi-stable rocker switch or a pushbutton (33).
11. The disconnecting device (1) as claimed in any one of the preceding claims, characterized in that furthermore a controller (60) is provided, via which an operating state of the vehicle is retrievable, and the controller (60) prevents or permits a disconnection by means of the disconnecting device (1) in dependence on the detected operating state.
12. A vehicle power electrical system having DC loads of greater than 12 KW, preferably in a motor vehicle, equipped with a disconnecting device (1) as claimed in any one of preceding claims 1 to 11, wherein the disconnecting device (1) is connected via its energy accumulator terminals (31, 41) to at least one energy accumulator (2).

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