WO2002050856A1

WO2002050856A1 - Trip for circuit breaker

Info

Publication number: WO2002050856A1
Application number: PCT/DE2001/004560
Authority: WO
Inventors: Josef Griesbeck; Hans-Georg Finger
Original assignee: Siemens Aktiengesellschaft
Priority date: 2000-12-19
Filing date: 2001-12-05
Publication date: 2002-06-27

Abstract

Trips, such as low voltage trips, or working current trips, in particular for power switches or power circuit breakers, here referred to together as circuit breakers, whereby the trip engages with the breaker mechanism of the circuit breaker, by means of a drive system on operation thereof. The drive in principle is a piezo-ceramic torsion strip (1), which, on failure of the operating voltage, or supplied voltage, engages with the breaker mechanism of the circuit breaker to release the above, by means of the bending out thereof into the said mechanism.

Description

description

Triggers for circuit breakers

The invention relates to a release, such as undervoltage release or shunt release, in particular for circuit breakers or circuit breakers, collectively referred to here as circuit breakers, in detail according to the preamble of claim 1. The trigger comes into engagement with the switch lock of the circuit breaker by means of a drive when it is started ,

Undervoltage releases are used to switch off circuit breakers when a specified operating voltage is undershot or fails in order to avoid dangerous operating states when the operating voltage returns due to starting machines. They are usually mechanically attached to the outside of the circuit breaker and coupled to the switching mechanism of the circuit breaker. A spring is generally used as the drive and is held under tension by an electromagnet. If the operating voltage drops below a predetermined value, the electromagnet drops and releases the spring, which normally opens the latch of the connected circuit breaker and thereby switches it off. When switching on again after the voltage recovery, the spring of the undervoltage release is tensioned and the electromagnet keeps the spring in its tensioned position. If an attempt is made to switch on the circuit breaker as long as sufficient operating voltage is not available, the electromagnet does not pull in and the spring keeps the latch of the circuit breaker open. Switching on is therefore not possible.

The decisive disadvantage of undervoltage releases is the electromagnet, which is constantly live and consumes energy and generates heat. In addition, the effort required for a coil that is resistant to permanent voltage is relatively high. Shunt releases are often used to herein collectively called circuit breaker or circuit breaker, ^'back breaker to turn off remotely using a current pulse or .auszulösen. They are usually mechanically attached to the outside of the circuit breaker and coupled to the switching mechanism of the circuit breaker. In turn, the drive is generally an electromagnet, which actuates an armature, which acts on the switch lock of the coupled circuit breaker and triggers, which in turn switches off the circuit breaker.

Often the switch-off is not effected by an impulse, but by the application of permanent voltage to the connections of the shunt release. Usually a solenoid coil is used which is voltage-proof against permanent voltage or an auxiliary contact is installed inside the shunt release, which interrupts the coil circuit after the circuit breaker has been switched off.

In practice, therefore, a separate switch lock is required in the shunt release to ensure that the coil circuit is switched off. If the circuit breaker is switched on again with an existing trip command, be it by hand or by remote control, the coil is energized and the lock of the circuit breaker is opened when the auxiliary contact is closed. Since the switching operation has already been initiated, the lock is mechanically loaded.

On the other hand, magnets that are resistant to constant voltage require a lot of copper, require a lot of space, consume a lot of energy and heat up the environment. However, you do not need an auxiliary switch or your own key switch, they simply keep the latch open continuously when voltage is applied. The invention has for its object to develop a universal release that is suitable as undervoltage release and shunt release and in which the disadvantages described are avoided.

The described task is solved by a trigger according to claim 1. Here, the drive is in principle a piezoceramic bending strip, which in the absence of the operating voltage, in the version as undervoltage release, or in the case of derived voltage, in the version as shunt release, by its bending or bending back into the circuit breaker of the circuit breaker engages in a unlatching manner. In principle, one can get by with a single trigger that eliminates the known variants described. One of the advantages is that constant energy consumption and heat generation are avoided. In the case of continuous voltage when determining as a shunt release, it is advantageous that the release does not have to be assigned a separate switch lock in order to open auxiliary contacts and to interrupt a coil circuit.

In the determination as a shunt release according to claim 2, when a shunt occurs or in the case of remote triggering by means of a pulse, the trigger is brought into engagement with the switch lock of the circuit breaker. In principle, the drive is again a piezoceramic bending strip, which, under an applied voltage, which is derived from the working current, engages in the circuit breaker of the circuit breaker by unlatching it.

In the case of the trigger in the determination as undervoltage release according to claim 3, the drive can in principle be a piezoceramic bending strip which, when the operating voltage is applied, is disengaged due to its bending out

Switch lock of the circuit breaker is.t and held at. The operating voltage drops below a voltage threshold by bending back into the circuit breaker of the circuit breaker, this interlocks.

An embodiment as working ^s' t omaμslöser or undervoltage releases requires only minor adaptation, wherein the trigger can also be designed so that it is immediately suitable for both determinations, optionally by corresponding deflection members and differently shaped action members for both determinations. It may also be sufficient to attach the trigger at a suitable location.

Regardless of the determination of the release of these can meet special requirements with einem- own energy accumulator operatively _j communicating.

A voltage generator can be connected to the piezoceramic bending strip in order to provide a suitable voltage for bending out the bending strip.

The voltage generator can be provided with a mains connection for installation AC voltage and can have a rectifier with a smoothing capacitor in order to provide the required DC voltage for the piezoceramic bending strip.

The trigger can, on the other hand, be provided with a voltage generator with a mains connection for AC voltage lower than the installation voltage of a supply network and can have a voltage multiplier with a rectifier circuit. This means that the release can also be operated with an AC voltage lower than the usual mains voltage.

On the other hand, the trigger can have a voltage generator with a mains connection for DC voltage, in particular for a DC voltage that is smaller than the installation voltage. voltage and accordingly have an AC voltage generator with a voltage multiplier and rectifier circuit.

Finally, a bus from building system technology can serve as a voltage generator, which, in addition to providing information, also supplies energy for supplying the electronics to subscriber stations. A special supply line is not required.

The bus for replacing a separate voltage generator can advantageously be the bus of the European Installation Bus Association.

The invention will now be explained in more detail with reference to exemplary embodiments shown roughly schematically in the drawing :)

1 shows a trigger with a piezoceramic bending strip, which can operate as an operating voltage with a conventional mains voltage of 230 volts AC. It has a rectifier circuit and, in the exemplary embodiment, a smoothing capacitor, which can also be dispensed with.

FIG. 2 illustrates a trigger with a piezoceramic bending strip which can be operated with a low AC voltage, for example of 24 volts, a voltage multiplier circuit and a rectifier circuit which provides the high voltage required for the operation of the piezoceramic bending strip.

FIG. 3 illustrates a trigger that can be operated with a low DC voltage, for example of 24 volts, the DC voltage being converted to AC voltage in an AC voltage generator and increased in a voltage multiplier circuit and in a downstream rectifier circuit in DC voltage for operating the Piezoceramic bending strip is converted. Such circuits can be made very small, since the piezoceramic bending strip has extremely low energy requirements.

The trigger according to FIG 1 can be determined as an undervoltage release or shunt release. Its piezoceramic bending strip 1 is connected to a voltage generator 2, which in the exemplary embodiment according to FIG. 1 is provided with a mains connection 3 for alternating installation voltage of, for example, 230 volts. In the exemplary embodiment, the voltage generator has a rectifier circuit 4 and a smoothing capacitor 5. The trigger can be activated by means of a drive, which here is the piezoceramic bending strip 1, when it is engaged in connection with the switching lock; of a circuit breaker to be loaded.

In the determination as an undervoltage release, when the operating voltage is absent or no longer high enough, the piezoceramic bending strip 1 is bent back into the switch lock of a circuit breaker by engaging it in a detaching manner.

In the determination as a shunt release, when the voltage is derived from the shunt, it bends out into the switch lock of the circuit breaker, in which it interlocks. In the case of an undervoltage release, the pawl is the

To position the switch lock clearly in the neutral position according to FIG. 1 at the end of the piezoceramic bending strip 1. If the operating voltage is sufficient, the bending strip 1 is then bent away from this rest position, so that it is bent out of engagement with the switch lock of the associated circuit breaker. If there is no operating voltage, bending out or bending back into the rest position leads to an engagement with a release element.

In the case of a release in the designation as a shunt release, the pawl must therefore be arranged in the bent position 6 of the bending strip. The piezoceramic bending strip 1 acts similarly to a conventional bimetallic strip. In the case of the piezoceramic bending strip, a sufficiently high voltage is used to deflect it to a useful extent, so that a latch can be released or unlatched. Piezo-ceramic bending strips are, for example, under the type designation "Piezoelectric Ceramics Parallel Bimorph Elements", order no. 4322020-1453 to -1462, offered by Philips on the market. A piezoceramic bending strip can be about 35 mm

Have length, 6 mm width and 0.6 mm thickness. Such an element has a deflection of 935 μ ± 20% with a free length of 30 mm when a voltage of 300 volts DC is applied. The approximately 1 mm deflection is sufficient to release a latch of common circuit breakers. The ^" current consumption of such an element is negligible since it behaves electrically like a capacitor. Its capacity is approximately 24 nF. All additional circuits, for example in the voltage generator 2, can be made very small due to the extremely low energy requirement of the piezoceramic bending element.

FIG. 2 shows a release with a mains connection 3 for an AC voltage lower than that of a conventional installation voltage. Its voltage generator 2 has a voltage multiplier circuit 7 and a downstream rectifier circuit 4. In the exemplary embodiment, a smoothing capacitor 5 is again provided.

In the exemplary embodiment according to FIG. 3, a trigger is illustrated which is provided with a voltage generator 2 with a mains connection 3 for DC voltage less than that of a conventional installation voltage. The DC voltage at the mains connection 3 can be 24 volts, DC voltage, for example. The voltage generator has an AC voltage generator 8, a downstream voltage multiplier cherschaltung 7 and a downstream rectifier circuit 4.

On voltage generator 2 ^', a bus of building system technology can be connected to its power supply when the bus except for information and energy leads to supply the electronics of subscriber stations. The generally low DC voltage can then be processed by a voltage generator of the type shown in FIG. 3 and made usable for the piezoceramic bending strip 1.

The bus of the European Installation Bus Association is advantageously suitable as a bus for supplying the voltage generator 2, for example via its network connection 3. ^'

In the simplest case, a chopper circuit is suitable as the AC voltage generator 8 in the voltage generator 2 according to FIG. DC voltage circuits and voltage multiplier circuits are common in a wide variety of designs.

Claims

claims

1. Triggers, such as undervoltage releases or shunt releases, in particular for circuit breakers or circuit breakers, collectively referred to here as circuit breakers, the trigger coming into engagement with the circuit breaker of the circuit breaker when it is started, characterized in that the drive is in principle a piezoceramic bending strip (1), which intervenes in the circuit breaker of the circuit breaker without its operating voltage or derived voltage due to its bending out or bending back.

I

2. Trigger according to claim 1 in the determination as a shunt release, in particular for circuit breakers or circuit breakers, collectively referred to here as circuit breakers, the trigger coming into engagement with the switch of the circuit breaker by means of a drive when an operating current occurs or in the case of remote triggering by means of an impulse due to the action of a pulse , characterized in that the drive is in principle a piezoceramic bending strip (1) which, under an applied voltage, which is derived from the working current, engages by releasing it into the switch lock of the circuit breaker.

3. The trip device according to claim 1 in the determination as an undervoltage release, in particular for circuit breakers or miniature circuit breakers, collectively called circuit breaker here, wherein the trigger arrives means of a drive when it falls below the ^'operating voltage below a predetermined Spannungsscnwelle engaging connection with the switching mechanism of the circuit breaker, characterized in that the drive is in principle a piezoceramic bending strip (1) which, when the operating voltage is applied, is kept out of engagement by the circuit breaker of the circuit breaker due to its deflection, and when the operating voltage drops below the voltage threshold - by bending back into the circuit breaker of the circuit breaker intervenes.

4. Trigger according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that the trigger is operatively connected to its own energy accumulator (9).

5. Trigger according to one of the preceding claims, that a voltage generator (2) is connected to the piezoceramic bending strip (1).

6. Trigger according to claim 5, d a d u r c h g e k e n n z e i c h n e t that the voltage generator (2) with mains connection (3) for AC installation voltage and has a rectifier circuit (4).

7. Trigger according to claim 5, d a d u r c h g e k e n n z e i c h n e t that the voltage generator (2) with mains connection (3) for AC voltage is less than an installation voltage and has a voltage multiplier circuit (7) with rectifier circuit (4).

8. Trigger according to claim 5, characterized in that the voltage generator (2) is provided with a mains connection (3) for ■ DC voltage less than the installation voltage and an AC voltage generator (8) with voltage supply. Multiple circuit (7) and rectifier circuit (4).

9. Trigger according to claim 5, d a d u r c h g e k e n n z e i c h n e t that a bus of the building system technology is connected to the voltage generator (2), which in addition to information also leads energy to supply the electronics of subscriber stations.

10. Trigger according to claim 5, so that the bus of the European Installation Bus Association is used as the bus.