WO2014131564A1

WO2014131564A1 - Disconnecting and switching circuit for the overvoltage protection

Info

Publication number: WO2014131564A1
Application number: PCT/EP2014/051750
Authority: WO
Inventors: Helmut Hirschmann; Peter Zahlmann; Edmund ZÄUNER; Florian Gaeck
Original assignee: Dehn + Söhne Gmbh + Co. Kg
Priority date: 2013-03-01
Filing date: 2014-01-30
Publication date: 2014-09-04
Also published as: CN105009246A; PL2962319T3; EP2962319A1; EP2962319B1; CN105009246B; SI2962319T1; DE102013003584B3

Abstract

The invention relates to a disconnecting and switching circuit for the overvoltage protection comprising at least one dissipation element, further one thermal disconnecting point which is integrated in the electrical connection path of the dissipation element, wherein the thermal disconnecting point comprises a movable conductor element, which is under a mechanical pretension and which, in the event of disconnecting, moves from a first position into a second position, wherein by reaching a second position an electrical switching is brought about, wherein a complete electrical disconnection of the dissipation element in relation to the connection path is only given once the movable conductor element has reached the second position. According to the invention, the thermal disconnecting point is formed by the movable conductor element and a fixed contact element, wherein the movable conductor element is fastened to the fixed contact element by a thermally detachable means and the contact element has a groove or an opening, in which a finger-like extension of the movable conductor element immerses in such a way that a disconnection between groove or opening and finger-shaped extension is only given when the second position of the movable conductor element is given.

Description

and switching device for the high voltage protection

description

The invention relates to a separation and switching device for the

High-voltage protection with at least one diverting element, in particular a varistor, further a thermal separation point, in the

electrical connection path of the diverter is incorporated, wherein the thermal separation point comprises a movable conductor element, which is under a mechanical bias and moves in Abtrennfall from a first position to a second position, wherein upon reaching the second position, an electrical switching is effected and a

complete electrical separation of the diverting element with respect to

Terminal path is given only when the movable conductor element has reached the second position, according to the preamble of claim 1,

Separating devices, even with short-circuit function, wherein in the separated or triggered switching state of the separator of the current path through the defective Abieitelement is in short circuit such that the current tommutiert from the diverter to a bypass, are known.

A so-connected low-resistance short-circuit path can e.g. be used to an upstream switching element, eg. B. a fuse, which is set to the short-circuit current of the network concerned to operate. However, it is also possible to maintain a defined continuous short circuit, which is defined as a so-called fail-safe state in certain applications.

In this regard, reference should be made to EP 0 860 927 A1, In this

Document is described an electromechanical device which monitors the current through a varistor and which after exceeding a

predetermined limit switches the short circuit in the bypass to the varistor via electromechanical contacts. The DE 3? 34 214 C2 shows a thermally triggered separating device whose switching element represents a changeover contact. The changeover contact closes the varistor circuit in a known manner via a soldering point. If the switching element is triggered, another contact is closed, which can be connected either as an internal or external defect indicator or just via a corresponding external connection as a short circuit.

DE 41 24 321 shows the possibility of additional backup in the event that even after failure ei nes first varistor switched redundant varistor is damaged. In this regard, the redundant varistor is disconnected either by opening a switch in the cross-current path or by opening the switch in the longitudinal current path of the power supply. At the same time there is a separation of the system to be protected from the network and an overvoltage protection.

Especially in photovoltaic systems due to the characteristic of the feeding source of the local operating current is approximately equal to the short-circuit current. A classic separation when heating a varistor m with separation device is not effective in such DC applications, since the system voltage of photovoltaic systems is up to 1000 V and the interruption ung of 1000 V DC circuits can be realized only with a considerable amount of design or equipment.

DE 10 2007 051 854 A1 shows a surge arrester arrangement with a housing and with at least one diverting element, for example a varistor, wherein the local solution should be able to safely conduct a short-circuit current, so that new fields of application result.

In this regard, known per se are provided for surge arresters with an additional connection, which extends the existing Abtrennfunktion by a short-circuit function, which leads temporary fault current. Specifically, it is proposed to design the addi tional connection in various ways, so that an activation from the outside of the correspondingly realized surge arrester is also possible as required. In this regard, a path of movement of the spring-biased conductor or a spring-biased bridge of the separator is at least one conductive element arranged, the first end comes in triggered disconnector with the conductor portion or the bridge in contact.

The second end of the conductive element is in communication with a second external electrical connection. The conductive element can be used later in the Abieiter, in addition to a separation function to realize a short-circuit or fail-safe function.

According to DE 10 200? 051 854 A1, the local conductive element can also be formed as a switching device. The bypass formed by the switching device in the event of a short circuit is not designed for continuous current carrying capacity. After the fault current has flowed over a certain time, the bypass is switched off. In this regard, the conductive element may be formed as a fuse. According to DE 10 2007 051 854 A1 moves in the event of an overload of Überspannungsabieiters the Anschl uss of the thermal separator to the connection point for the short-circuit element in the bypass. In this case, the short-circuit element is closed. The resulting during the opening of the thermal separation device arc is to be guided by the contact elements and extinguish automatically, on reaching the short-circuit contact. Immediately after reaching the short-circuit contact, the arc then goes out and current flows through the bypass, e.g. designed as a fuse.

However, it has been shown that when switching an undefined transition region is present, in which the movable part of the separating device has already left the surge arrester, but not yet with the switching element, for. As a backup, i n contact has arrived. In this transition region burns an arc, which can be a significant disadvantage for the operation of a corresponding device.

From the foregoing, it is therefore an object of the invention to provide a further developed separation and switching device for overvoltage protection, this comprising at least one Abieiter, in particular a varistor, as well as a thermal separation point, in the electrical

Connection path of the Abieiter is involved. The specified separation and switching device should ensure that even during the separation and Switching operation in the course of the mechanical movement of the corresponding

Conductor no unwanted arcs occur and thus the reliability of a device equipped in this regard is increased.

The object of the invention is achieved by the feature combination according to claim 1, wherein the dependent claims comprise at least expedient refinements and developments.

It is therefore of a separation and switching device for the

Overvoltage protection assumed »which has at least one discharge element. Furthermore, at least one thermal separation point is present, which in the electrical connection path of the respective diverting element

The at least one thermal separation point contains at least one movable conductor element, which is under a mechanical bias. This mechanical bias can be achieved by a

additional spring element can be generated. But there is also the

Possibility _» that the movable conductor element itself elastic, ie

has resilient properties. In the separation case, the conductor element moves from a first position to a second position, wherein upon reaching the second position, the desired electrical switching is effected. In contrast, in the first position, the corresponding diverting element is incorporated in the connection path, i. connected.

A complete electrical separation of the respective diverting element with respect to the connection path is given only when the movable conductor element, the second position, i. has reached the so-called switching position.

This measure ensures that no unwanted arc occurs during the movement path of the conductor element.

According to the invention, the thermal separation point is formed by the movable conductor element and a fixed contact element. The mobile one

Conductor element is fixed to the fixed contact element by a thermally triggered means. This thermally triggerable agent may be, for example, a solder or a thermally sensitive adhesive. Furthermore, the contact element has a groove or an opening, for example in the form of a slot, in which a finger-like extension of the movable conductor element is immersed such that a Außerkontaktkommen between groove or opening and finger-like extension is given only when reaching the second position of the movable conductor element. Over the required path of movement of the conductor element thus holds the finger-like projection still in contact with the fixed contact element and dissolves from this only after the switching point is given.

The longitudinal extent of the finger-like extension is matched to the distance between the fixed contact element and a respective changeover contact.

The at least one diverting element may be a varistor.

Although it is explained above that the contact element has a groove or an opening and the movable conductor element has a finger-like extension, in this regard, a kinematic reversal may be given by z. B. a finger is provided on the fixed contact element, which dips into a slot-shaped opening or a groove of the movable conductor element.

The aforementioned changeover contact may be formed as a so-called wiper or sliding contact and in this regard have a contact surface which extends over a Teilbewegungsweg of the movable

Ladder element extends.

The movable conductor element is ausgestaltend provided with a Umschaltkontaktfläche, which occurs during the switching operation in operative connection with the m contact surface of the Umschaltkontakts.

In an alternative embodiment, extending from the movable conductor element in the direction of the second position, a resilient, resilient contact lug, which in the separation process, the second position in front of the

achieved actual movable conductor element. The contact lug can be here as an integral part of the movable

Conductor element, e.g. designed as a curved punching tongue to be executed.

Particularly preferably, the movable conductor element is executable as a metallic stamped and bent part and can take over all functions in a simple and cost-effective manner.

According to the second embodiment of the invention, the changeover contact has a contact surface which forms a stop primarily for the contact lug and secondarily for a respective free end of the movable conductor element.

In a preferred embodiment, the electrical switching takes place on a fuse.

In this case, a first securing pole is connected to a terminal of the diverting element and a second securing pole is connected to the changeover contact in connection or as part of this contact.

The solution according to the invention is also particularly suitable for use in overvoltage protection in the field of photovoltaic systems.

The invention will be explained below with reference to exemplary embodiments and with the aid of figures.

Hereby show:

Fig. 1a to c a first embodiment of the invention with a

grinding switching contact and

Fig. 2a to c show a second embodiment of the invention with a resilient contact lug, designed as a pre-bent

Punching tongue.

Although in the following embodiments of a

Deriving element is assumed in the form of a Metalloxidvaristors, the invention idea is readily transferable to separation and Switching devices which use or use surge arresters of a different design, provided that thermal monitoring of the operating state is relevant in this regard.

According to the illustrations of Fig. 1a to 1c is of a separation and

Switching device for a surge absorber is assumed, wherein a discharge element 1, e.g. designed as a varistor MOV, is disposed within a housing of an overvoltage protection plug-in part 2.

In the electrical connection path 3 of the varistor 1 is a thermal

Separation point 4 (ATV) involved.

The thermal separation point 4 comprises a movable conductor element 5, which is under mechanical prestressing or has resilient properties according to the figurative representations of the embodiment itself.

In the separation case, the conductor element 5 moves from a first position (Fig. 1a or 2a) to a second position (Fig. 1c and 2c), wherein the second position causes an electrical switching.

Upon reaching the second position, i. the end Stel ment of FIG. 1c and 2c, the varistor 1 is disconnected from the connection path 3, i. a corresponding contact 6 of the varistor 1 is no longer in communication with the movable conductor element 5 towards the connection path 3.

From the course of the illustrations according to FIGS. 1 a to 1 c and 2 a to 2 c, it can be seen that the electric separation of the varistor with respect to the connection path 3 is given only when the movable conductor element 5 has reached the second (respectively left side) position.

The actual thermal separation point 4 is, as already described, formed by the movable conductor element 5 and a fixed contact element 6, e.g. may simultaneously be a corresponding terminal contact of the varistor 1.

The movable conductor element 5 is fixed to the contact element 6 by a figuratively not shown thermally triggered means, for. B. fixed a solder. According to the exemplary embodiment according to FIGS. 1 a to 1 c, the contact element 6 has a groove 7 or a slot-like opening in which a finger-like extension 8 of the movable conductor element 5 is inserted, such that a contact between the opening 7 and the finger-like extension 8 does not occur with reaching the second position of the movable

Ladder element 5 is given.

The longitudinal extent of the finger-like extension 8 is on the distance between the fixed contact element 6 and the changeover 9th

Voted.

The changeover contact 9 can be used as a wiper or sliding contact, as shown in FIGS. 1a to 1c, are executed.

In this regard, the switching contact 9 ei ne underside contact surface which extends over a partial movement of the movable conductor element and a mating contact there existing 1 1.

This mating contact surface 11 can also be referred to as Umschaltkontaktfläche, which occurs during the switching operation in operative connection with the contact surface 10 of the changeover 9.

In the course of triggering the thermal separating device 4 and the

Movement of the conductor element 5 from the closed to the disconnected and then switching position is closed ei n circuit to a fuse 12, so that a dazuzügl I new path on the elements 3 and 12th

formed.

The fuse 12 can, as shown in the figures, be integrated into the overvoltage protection plug-in part 2.

In the embodiment according to FIG. 2a to 2c are substantially the same functional elements as described with reference to FIGS. 1a to 1c, so that reference can be made in this regard to the above descriptions. In an alternative, as shown in Figs. 2a to 2c extends from the movable conductor element 5 in the direction of the second (left-hand) position, a resilient resilient contact lug 13, which reaches the second position (left side) in front of the actual movable conductor element 5 in the separation process ,

The contact lug 13 can be designed as an integral part of the movable conductor element, in particular as a pre-bent punching tongue.

The switching contact has in the embodiment according to FIGS. 2a to 2c on a contact surface which serves as a stop 14 for a corresponding end of the contact lug 13 and sekundir for a respective free end 15 of the movable conductor element 5.

Also in the embodiment according to FIGS. 2a to 2c is the

Switching to the fuse 12 shown with separation of the varistor. 1

A first securing pole 16 is connected to a terminal 17 of the diverting element or varistor 1, wherein a second safety pole 18 is connected to the switching contact 9 in the connection or forms part of this contact.

As particularly shown in FIG. 2a and 2b is traceable, the local movable conductor element 5 can be carried out with a contact lug 13 in a very simple manner as stamped and bent part, wherein the area of the contact lug 13 is separable via a corresponding punching cut and can be pre-bent, so that the in FIG , 2a recognizable Abwinklungsabstand between the punching tongue 13 and the conductor element 5 sets, which is fixed by a solder on the contact 6.

The two transition positions according to FIGS. 1b and 2b show that in this position, both the varistor 1 is still integrated in the connection path 3, as well as a contacting of the fuse 12 shown there is given.

Claims

claims

1. disconnecting and switching device for overvoltage protection with at least one diverting element furthermore a thermal separation point (4), which is integrated into the electrical connection path (3) of the divider element, wherein the thermal separation point (4) comprises a movable conductor element (5), which is under a mechanical bias and moves in Abtrennfall from a first position to a second position, upon reaching the second position, an electrical switching is effected, wherein a complete electrical separation of the diverter with respect to the Anschl usspfads is given only when the movable conductor element (5) has reached the second position,

characterized in that

the thermal separation point (4) is formed by the movable conductor element (5) and a fixed contact element (6), wherein the movable conductor element (5) is fixed to the fixed contact element (6) by a thermally triggered means, further the contact element (6 ) has a groove or opening (7) in which a finger-like projection (8) of the movable conductor element (5) is immersed such that an outward contact between the groove or opening (7) and finger-like projection (8) until reaching the second position given the movable conductor element (5).

2. Separating and switching device according to claim 1,

characterized in that

the diverting element is a varistor (1).

3. disconnecting and switching device according to claim 1 or 2,

characterized in that

the longitudinal extent of the finger-like extension (8) is matched to the distance between the fixed contact element (6) and a change-over contact (9).

4. disconnecting and switching device according to claim 3,

characterized in that

the changeover contact (9) is designed as a wiper or sliding contact and in this respect has a contact surface (10) which extends over a partial movement path of the movable conductor element (5; 11).

5. disconnecting and switching device according to claim 4,

characterized in that

the movable conductor element (5) has a changeover contact surface (11) which, during the switching process, comes into operative connection with the contact surface (10) of the changeover contact (9),

6. separating and switching device according to one of claims 1 to 3, characterized in that

extending from the movable conductor element (5) in the direction of the second position, a resilient, resilient contact lug (13), which reaches the second position in front of the movable conductor element (5) in the separation process.

7. disconnecting and switching device according to claim 6,

characterized in that

the contact lug integral part of the movable conductor element, designed as a pre-bent punching tongue is.

8. disconnecting and switching device according to claim 3 and 6 or 7, characterized in that

the changeover contact (9) has a contact surface (14) which forms a stop primarily for the contact lug (13) and secondarily for a respective free end of the movable conductor element (5).

9. Abtren n- and switching device according to one of the preceding claims,

characterized in that

the electrical switching to a fuse (12) takes place.

10. disconnecting and switching device according to claim 3 and 9,

characterized in that

a first fuse pole (16) is connected to a terminal (17) of the diverter element (1) and a second fuse pole (18) is in communication with the changeover contact (9) or forms part of this contact (9).