Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/0039—Means for influencing the rupture process of the fusible element
  • H01H85/0047—Heating means
  • H01H85/0065—Heat reflective or insulating layer on the fusible element
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H39/006—Opening by severing a conductor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/0039—Means for influencing the rupture process of the fusible element
  • H01H85/0047—Heating means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/0039—Means for influencing the rupture process of the fusible element
  • H01H85/0047—Heating means
  • H01H85/0056—Heat conducting or heat absorbing means associated with the fusible member, e.g. for providing time delay
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
  • H01H85/05—Component parts thereof
  • H01H85/055—Fusible members
  • H01H85/12—Two or more separate fusible members in parallel

Definitions

• the invention is based on a fuse for low-voltage applications for the protection of devices that can be connected to a supply network, in particular of overvoltage protection devices, such as
• Spark gaps or varistors consisting of at least one, located between two contacts, arranged in a fuse housing fuse element and a KurzrösRoyce with internal separation distance to the fuse element according to claim 1.
• Conventional fuses are used in large quantities and in many applications to overcurrent or
• fuses are used as backup protection for overvoltage arresters in the so-called shunt branch.
• shunt branch must be one
• Overvoltage protection device in case of failure in a defined impedance to. This can be seen analogously to a short-circuiting device which is connected in parallel with the overvoltage protection.
• the fuse may react with the short-circuit current of the network be charged and only if this is sufficiently large, done by the fuse a defined shutdown.
• the fuse In the case of a low-resistance short circuit, the fuse is loaded with the available maximum short-circuit current. In the case of an impedance-related short circuit, the current load of the fuse drops, which makes switching off at low currents questionable. The arc or arc erosion to the fusible conductor is impedance-like, limiting the current. This possibly results in a delayed shutdown or only a further local damage to the fuse conductor, causing very long arc times or destruction of the fuse through the
• circuit breakers with tripping characteristics is an alternative, but these switches are much more expensive than fuses and therefore not suitable for all applications for cost reasons.
• Sever separation device. DE 42 11 079 AI shows such a solution in which a pyrotechnic charge is ignited when the current flowing through the fuse and of a
• Current detection device detected current has a strength that is greater than a predetermined threshold.
• the control can be carried out depending on the fault current from a separate control.
• DE 10 2014 215 279 AI discloses a fuse for a device to be protected, which is connected in series with the fuse.
• DE 10 2014 215 279 A1 refers to the melt integral I 2 t. Accordingly, the melting of a fusible conductor is determined by its material and geometry properties, so that depending on the material and / or geometry of the fusible conductor a respective amount of heat Q for evaporation of the
• Fuse to be protected device is an overvoltage protection device, because this should allow high currents to happen at short notice, without causing the fuse, but at the same time with low residual currents, such as damage to the
• This device is based on two electrical, in particular plate-shaped connection parts, which a different
• connection parts Between the connection parts, an insulation gap is formed.
• the short circuit is over one, at least partially
• connection parts are closely adjacent according to the previously known solution and arranged to include the insulation gap.
• Insulation path is formed as an insulating film or film-like coating. Furthermore, in the immediate vicinity of the
• connection parts Potential separation between the connection parts is canceled and the desired short circuit occurs.
• a device with an internal short-circuiting function according to DE 10 2013 005 783 AI requires a tuned separate, external overcurrent protection device to interrupt the short circuit.
• Fuse consists of between two contacts
• Auxiliary connection or auxiliary contact have the possibility of triggering a short-circuit current. It should be dispensed with external, so gleichtragsente switch.
• the object of the invention is achieved by a fuse according to the combination of features according to claim 1, wherein the
• the fuse according to the invention is intended in particular for use in the shunt arm in combination with surge protection devices.
• the insulation element used in particular the insulation film, meets the necessary electrical requirements for an insulation distance for use in the shunt branch, so that no additional external
• both a metallic, low-resistance short circuit between the one or more fuse links and the auxiliary contact, but also a short circuit with impedance and sparking can be realized.
• the insulation element is protected against thermal damage during pulse loads due to heating of the melt or the fuse. So that the short-circuit path of the fuse does not respond to normal functions, the requirements of the invention
• the fuse according to the invention may comprise one or more parallel fuse elements.
• the fuse elements can be surrounded by a quenching medium within the fuse housing.
• the fuse element (s) may have conventional bottlenecks. Alternatively or additionally, there is the possibility that
• a triggering device for controlled separation of the fusible conductor is activated in case of malfunction or overload conditions of the respectively connected device.
• a section of the fusible conductor in the fuse housing are exposed, wherein a mechanical separator in the extinguishing agent-free area can be introduced via an access in the housing, depending on the trigger device to destroy the at least one fuse independently of its melting integral mechanically.
• Such a separating element can be formed as a blade or cutting edge. It is also possible, the separator of a
• the at least one fusible conductor may have a plurality of electrical bottlenecks known per se, as already mentioned above, which are designed for the rated load of the respective fuse. Further, additional geometric bottlenecks can be provided, which are claimed to train separated depending on the trigger unit by rupture.
• the switching device has a separating line forming the
• Isolation element which undergoes a state change by an exothermic activator and the activator with at least one
• Control terminal is connected.
• the insulating element can be formed as an insulating film.
• the exothermic activator can also be realized as a film, here as a reaction film, wherein the reaction film is in communication with an ignition device.
• the exothermic activator may have a bridge igniter, which directly or indirectly destroys the insulation element.
• the bridge igniter can further drive a conductive element to overcome the separation distance, whereby the desired short circuit is triggered.
• the ignition device preferably has an ignition element which heats up when current flows, the ignition element being connected to the at least one control connection.
• a plurality of fusible leads can be formed parallel to each other, wherein the plurality of fusible leads are guided by a disk located on the fuse housing and located in the housing.
• the switching device can then be on or on the disc.
• the one or more fusible links have sections of reduced area and / or reduced cross-section over their respective longitudinal extent. However, the switching device according to the invention is located outside of these reduced area and / or cross-section side reduced sections.
• a cylindrical fuse housing preferably cap-shaped contacts are used, the short-circuit auxiliary contact is guided over one of the cap-shaped contacts. In this regard, an isolated, severed area may be formed in the respective cap forming the auxiliary contact.
• Figure 1 is a plan view of a fuse element for a capsule fuse with bottlenecks.
• Fig. 2 is a sectional view through a fuse
• cap-shaped contacts and integrated switching device
• FIG. 4b shows exemplary embodiments of the ignition device with an ignition element A heated when the current flows; FIG. B;
• Fig. 5 shows a further embodiment of the fuse according to the invention in a schematic representation and in longitudinal section with two substantially parallel fused conductors, the a disc are guided, wherein the switching device is located on the disc;
• FIG. 6a; 6b shows a further embodiment of the invention
• Bridge igniter is used as an activator, which destroys the insulating element and via a movable part, which is conductive, produces the short-circuit state, wherein Fig. 6a, the normal state of the switching device before closing and the
• Fig. 6b illustrates the state of the switching device after closing, that is, the short circuit case.
• Overvoltage protection elements spark gaps or varistors
• Overvoltage protection elements or overload due to high or too long lasting overvoltages or overcurrents may cause gradual aging or destruction of the corresponding
• the thermal separation devices can within their dimensions
• varistors often indicate the maximum nominal current value of back-up fuses for adequate protection.
• Conventional fuses generally respond well below their theoretical adiabatic melting integral value at nominal current load.
• the load limit of the varistors is already well above the theoretical values of the fuses and thus far above the practical maximum values.
• pulse values which the varistors divert several times without any problems can lead to the destruction of the backup fuse even with a single load. For this reason, manufacturers of varistors often recommend larger,
• the proposed solution is based on one or more parallel fuse fusible conductors, preferably arranged in an extinguishing medium.
• the fusible links have bottlenecks in series, the number of which corresponds to the usual design for the corresponding nominal voltage of the fuse.
• the fuses according to the invention have a third,
• Short-circuit current carrying connection which is guided radially or axially outwards. Inside the fuse is the
• Switching device which is actively but possibly also passively actuated. This switching device meets the requirements regarding the
• Dielectric strength for application in shunt branch At least the dielectric strength corresponds to the protection level of the surge arrester to be protected during normal operation.
• the switching device is designed so that a preferred
• the switch is designed for a short reaction time as a short-circuiter on the basis of an exothermically reacting film or on the basis of using a bridge igniter.
• an internal shorting bridge can be used with a single switch.
• the short-circuiting bridge can be low-resistance but also impedance-affected.
• Pulse current carrying capacity of the fuse or melt, in which no separation of the fuse is to be effected in the fusible conductor is to be effected in the fusible conductor.
• the dimensioning of the fuse elements determines the time / current characteristic.
• the auxiliary contact of the fuse and thus also the entire short circuit path has a current carrying capacity, which satisfies this characteristic at least in the range of the expected short-circuit currents.
• the pulse current loads on varistor-based heaters are lower than those based on spark gaps.
• lightning arresters reach a maximum load of 100 kA 10/350 ps.
• Fuse of a fuse should satisfy the above-mentioned requirement in the described application.
• the fuse in a standard 230/400 V power supply for a voltage of 400 V is suitable.
• Fuse is the reduction of the rated current of the fuse or the design of a flat time / current characteristic. This allows one
• the arc erosion between the fusible conductor and the auxiliary contact can be used in order to achieve a sufficient separation distance more quickly, especially at low currents.
• Fig. 1 shows a conventional fusible link for a fuse, designed as a band-shaped fusible conductor 1 with bottlenecks 2, which lead to an area or cross-sectional reduction in the corresponding area.
• the bottlenecks 2 shown in principle in FIG. 1 are already made longer in comparison to known bottlenecks in the longitudinal direction of the fusible conductor 1. This results in an advantageous lowering of
• FIG. 2 now shows a longitudinal section through a fuse with fuse housing 6 and cap-shaped terminal contacts 9. Within the fuse housing 6, the inventive externally activatable switching device is located.
• the illustrated fusible conductor 1 has the already explained bottlenecks 2 in a partial section of its longitudinal extent. In the section of the fusible conductor 1 not occupied by constrictions, a short-circuiting auxiliary contact 3 is located below the fusible conductor and a further short-circuiting auxiliary contact 3 is located above the fusible conductor 1.
• a sandwich arrangement of an insulating film 4 and an exothermic reaction film 5 is located within the housing 6 of the fuse.
• the exothermic reaction film 5 is connected to an ignition device 7 in
• Connection standing which can be controlled via one or more control lines 8.
• control lines 8 connection standing, which can be controlled via one or more control lines 8.
• Ignition element which is overloaded at a low current and forms an arc (see Fig. 4b).
• the ignition can also be carried out with a flashover by a spark gap, a transformer or the like or by means of a thermal heating circuit.
• the externally accessible part of the short-circuiting auxiliary contact 3 is located in a wall section of the housing 6, but can also be led out in the region of one of the connecting caps 9, as shown in FIGS. 6 a and 6 b.
• the switching device according to FIG. 2 above the fusible conductor 1 starts from a reaction foil 5 which is almost in direct contact with the fusible conductor 1. In this arrangement, it is ensured that the reaction foil 5 is not accidentally triggered or not damaged when the fusible conductor 1 is heated during impulse loading. If this is impossible or only possible to a limited extent due to loads or the given construction, it can be provided with an electrically conductive layer below the fusible conductor 1 by means of an exemplary arrangement
• the insulation film 4 is dimensioned so that the operating voltage of the network and also the usual function of the overvoltage protection do not cause a breakdown by breakdown.
• Temperature stress for example, impulse loads, does not lead to thermal damage to the insulation film and thus not to
• the film 4 can be applied in the region of the undiminished cross-section of the fusible conductor (as shown).
• the fusible conductor may also have additional cooling surfaces, for example in the form of spacers.
• a further material can be arranged between the fusible conductor and the insulating film, which forms a thermal barrier.
• FIG. 4a illustrates a side view of a fusible conductor 1 with a switching device according to the invention, omitting the fuse housing and the connection caps.
• the switching device As shown in FIG. 4a, the switching device as
• reaction film 5 is above the reaction film 5
• Insulation film 4 and is suitably connected by means of ignition device 7, which is controlled via terminals 8. Due to the arrangement of the element 10 between the fuse element 1 and insulating film 4 latter is against thermal overload
• a minimal gap region 12 between the fusible conductor 1 and the insulating film 4 or the part 10 can be provided.
• the design of this gap region can be made so that upon actuation of the switch, the gap region 12 is overturned passively.
• FIG. 4a also allows in principle a
• 4b shows in various views design variants for an ignition device with an ignition element A or B.
• the ignition element A can be realized, for example, as a printed fusible conductor on a printed circuit board.
• the ignition element B is arranged in a cutout of a printed circuit board as a wire, which is subjected to a heating with a corresponding current flow, so that the exothermic reaction of the reaction foil can be triggered.
• the fusible conductors 1 are guided through a common plate 13 of material with good electrical conductivity or impedance.
• the disc 13 is supported on the inner wall of the fuse housing 6.
• the switching device according to the invention is located on or on the disc 13th
• the disc 13 may be made of metal, but also of conductive ceramic or of graphite.
• the metallic part 16 bridges the distance to the auxiliary contact 3 or through an insulating film between the aforementioned parts.
• FIGS. 6 a and 6 b show a foil insulation 14 in this regard.
• the introduction of the auxiliary contact 3 and the control lines 8 can take place axially through one of the connection caps 9.
• the auxiliary contact 3 is electrically isolated, for example, with an insulating part 15 of the cap 9.
• Within the fuse is located near the disc 13, a region without extinguishing agent filling. In this area, the insulating film 14 is attached, which by the
• Auxiliary contact 3 is isolated from the disc 13. In the area of the auxiliary contact 3, the mentioned movable part 16 is integrated, in which the bridge igniter is located as an actuator 17.
• the part 16 is moved in the activated case in the direction of film 14 and disc 13. In this case, the insulating film 14 is destroyed.
• the part 13, that is, the disc, but also the conductive part 16 may be provided with a notching device in order to quickly and safely sever the insulation film 14.
• the movement of the part 16 is stopped at the disc 13.
• the disk 13 is electrically conductively connected to the auxiliary terminal 3 via the metallic part 16. This connection can be supported positively. A further improvement of the connection is possible if a targeted deformation of the metallic part 16 takes place or
• the current-carrying capacity of this embodiment is with the desired time / current characteristic and the fuse in short-circuit currents in
• Fig. 6a shows the normal state of the switching device
• Shape memory alloy or bridge igniter or reaction film is activated, this can be done via a proportionate stream.
• This stream can be from the adjacent grid or a separate

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• Fuses (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

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ID=62909828

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Citations (8)

Family Cites Families (6)

• 2017
  • 2017-11-10 DE DE102017126419.1A patent/DE102017126419A1/de not_active Ceased
• 2018
  • 2018-02-01 WO PCT/EP2018/052457 patent/WO2018145978A1/de unknown
  • 2018-02-01 EP EP18702984.8A patent/EP3580772B1/de active Active
  • 2018-02-01 SI SI201830335T patent/SI3580772T1/sl unknown
  • 2018-02-01 CN CN201880010795.0A patent/CN110383413B/zh active Active
  • 2018-02-01 JP JP2019563671A patent/JP6884231B2/ja active Active

Patent Citations (9)

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