DE102018209114B3 - Circuit breaker with monitoring device and method therefor - Google Patents

Abstract

The invention relates to a circuit breaker (1) with monitoring device (Ü) comprising an electronic switch (S1) and a mechanical changeover switch (S2), wherein the mechanical changeover switch (S2) has a first connection (NC), a second connection (NO) and a third terminal (COM), wherein in a rest position of the mechanical changeover switch (S2), the first terminal (NC) to the third terminal (COM) is connected and wherein in a working position of the mechanical changeover switch (S2) of the second terminal (NO) the third terminal (COM) is connected, wherein the electronic switch (S1) to the third terminal (COM) of the mechanical changeover switch (S2) is connected as a series circuit, wherein when switching the circuit breaker (1) in a first switching state, first the electronic switch (S1) is activated, wherein at the first port (NC) by means of the monitoring device (Ü) is measured, whether at the first port (NC) in Essentially the same potential as at the third terminal (COM) is present and if so, in a subsequent further switching state, both the electronic switch (S1) is activated and the mechanical changeover switch (S2) is in the working position. Furthermore, the invention relates to methods for the circuit breaker.

Description

The invention relates to a circuit breaker with monitoring device and method for this.

background

From various areas it is known to use electronic circuit breakers.

From the DE 10 2004 036 252 A1 An electrical system with a relay-controlled electrical load is known. The relay can be monitored for load current, supply voltage, ie in relation to the switched input. From the DE 10 2014 016 218 A1 For example, a system and method for monitoring relay contacts is known. In each case, an additional signal emitter is switched on the sides of the switch and evaluated an additional high-frequency signal. From the EP 2 587 512 B1 The applicant is aware of a safety-related switching device with forced operation. In a forced operation, for example, the normally closed contact and the further contacts, the switching contact and / or a normally open contact are coupled to one another such that the normally closed contact and the normally open contact can not be closed at the same time. From the DE 10 2006 013 329 A1 is a method for error detection of a network system known. In this system, a defined voltage potential is supplied to a bus branch by means of an additional switching means to detect the disconnection state of a relay. From the DE 10 2015 121 194 A1 Furthermore, a device with integrated protection course is known, wherein the electronic switch is driven on the basis of a certain current.

In many areas of electrical engineering, galvanic isolating circuit breakers are also used. In the case of these circuit breakers, the output should be galvanically isolated in the event of a switch-off.

State of the art

Therefore, e.g. electronic circuit breakers are used in which the galvanic isolation is provided via a relay.

However, mechanical contacts, such as those used in relays, have the property that the switching contacts can bond / weld, so that reliable galvanic isolation is no longer possible.

However, it is not possible for the user to recognize in the previous circuit breakers whether the galvanic isolation is ensured without carrying out a separate measurement on the device, possibly in conjunction with an inoperative setting.

task

Based on this, it is an object of the invention to provide a circuit breaker with monitoring device and method for this, which make it possible to detect a no longer existing galvanic isolation.

solution

The object is achieved by means of a circuit breaker with monitoring device according to claim 1 or by means of method according to claim 11. Further advantageous embodiments of the invention are specified in the respective dependent claims, the description and in the figures.

list of figures

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

• 1 eine Nebeneinanderordnung von schematischen elektrischen Ersatzschaltbildern zu Verfahrensschritten gemäß Ausführungsformen der Erfindung,
• 2 eine Nebeneinanderordnung von schematischen elektrischen Ersatzschaltbildern zu Verfahrensschritten gemäß Ausführungsformen der Erfindung,
• 3 eine schematische Darstellung von einem elektrischen Ersatzschaltbild gemäß einem Aspekt der Erfindung,
• 4 eine schematische Darstellung von einem elektrischen Ersatzschaltbild gemäß einem weiteren Aspekt der Erfindung, und
• 5 eine weitere schematische Darstellung von einem elektrischen Ersatzschaltbild gemäß einer Ausführungsform der Erfindung.

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• 1 a juxtaposition of schematic electrical equivalent circuit diagrams to process steps according to embodiments of the invention,
• 2 a juxtaposition of schematic electrical equivalent circuit diagrams to process steps according to embodiments of the invention,
• 3 1 is a schematic representation of an equivalent electrical circuit diagram according to an aspect of the invention;
• 4 a schematic representation of an electrical equivalent circuit diagram according to another aspect of the invention, and
• 5 a further schematic representation of an electrical equivalent circuit diagram according to an embodiment of the invention.

Hereinafter, the invention will be illustrated in more detail (with reference to the figures). It should be noted that different aspects are described, which can be used individually or in combination. That Any aspect may be used with different embodiments of the invention, unless explicitly illustrated as a mere alternative.

Furthermore, in the following, for the sake of simplicity, reference will generally only ever be made to one entity be taken. Unless explicitly stated, however, the invention may also have several of the entities concerned. As such, the use of the words "a,""an" and "an" is to be understood merely as an indication that at least one entity is used in a simple embodiment.

Insofar as methods are described below, the individual steps of a method can be arranged and / or combined in any desired order, unless the context explicitly provides otherwise. Furthermore, unless expressly stated otherwise, the processes can be combined with one another.

Figures with numerical values are generally not to be understood as exact values, but also include a tolerance of +/- 1% up to +/- 10%.

References to standards or specifications or standards shall be construed as references to standards or specifications or standards in force at the time of the application and / or, if a priority is claimed, at the time of the priority application. However, this is not a general exclusion of applicability to subsequent or replacement standards or specifications or standards.

"Adjacent" explicitly includes, but is not limited to, an immediate neighborhood relationship. In the following, "between" explicitly includes a situation in which the intermediate part has an immediate neighborhood to the surrounding parts.

In particular, in the process industry, a galvanically isolating circuit breaker is often required, which shuts off the output in the event of overload or in the event of a short circuit.

Exemplary electrical equivalent circuit diagrams according to embodiments of the invention are shown in FIGS 3-5 demonstrated. In the 1 and 2 Simplified equivalent circuit diagrams are shown next to corresponding method steps.

An inventive circuit breaker 1 with monitoring device Ü has at least one electronic switch S1 and a mechanical changeover switch S2 on. The electronic switch S1 For example, it may be a switching transistor, in particular a field effect transistor.

Without limiting the generality can be provided that at an input voltage Uin - as in 4 indicated - also several switched outputs Uout can be arranged. Hereinafter, it is assumed for the understanding of the invention that per input Uin a through the circuit breaker 1 controllable output Uout is available.

The mechanical changeover switch S2 , eg a relay, has a first connection NC , a second connection NO and a third connection COM on, wherein in a rest position of the mechanical changeover switch S2, the first connection NC with the third connection COM is connected and wherein in a working position of the mechanical changeover switch S2 the second connection NO with the third connection ( COM ) connected is. ie S2 can be designed as a relay with changeover contact.

The electronic switch S1 is with the third connection COM of the mechanical changeover switch S2 connected as a series circuit. In this case, an immediate sequence as well as a series connection with further (intermediate) components can be provided.

When switching on the circuit breaker 1 in a first switching state, the electronic switch is initially S1 activated, whereby at the first connection NC by means of the monitoring device Ü is measured, whether at the first port NC essentially the same potential as at the third port COM is applied.

This can for example be accomplished by both the third port COM as well as at the first connection NC in each case a voltage divider is arranged, from each of which a voltage Uout . Urel-check for direct comparison (eg at the input of a differential operational amplifier) or for indirect comparison (eg after A / D conversion by comparison of numerical values) is provided. Of course, even with a suitable voltage can be dispensed with a voltage divider, and the respective voltages are fed directly to an evaluation. Without limiting the generality of course, other components such as capacitors, ferrite cores, etc. may be provided to provide other properties available. However, these are not essential to the understanding of the invention and therefore omitted.

If at the first connection NC essentially the same potential as at the third port COM is present, in a subsequent further switching state, both the electronic switch S1 be activated as well as the mechanical changeover switch S2 are in working position.

That is, it is now possible to determine whether the changeover contact by checking the voltage at the first terminal compared to the third terminal COM the mechanical is glued, because it is now possible to determine whether the changer of S2 from the second port NO solved or not. This is accomplished by using a welded / glued changer on the first connector NC essentially a different potential than the third connection COM is applied.

A corresponding method will now be described on the basis of 1 be explained in the event of switching. That is, in this method, it is checked before permanently switching on, whether the contact is glued / welded, and thus the electrical isolation in the event of switching off is no longer given.

It is assumed that the circuit breaker 1 as previously configured. In one step 100 Now, first the electronic switch S1 activated. This is symbolized in the symbolic representation of the equivalent circuit diagram by a triangle. Subsequently, the state of the non-activated, ie the non-actively driven, mechanical switch S2 determined. This will be done in a further step 200 by means of the monitoring device Ü Check if at the first port NC essentially the same potential as at the third port COM is present, and if so, subsequently both the electronic switch S1 in one step 400 activated as well as the mechanical changeover switch S2 in working position in step 300 is spent.

In one embodiment of the invention, in the event of a fault, that is, in the first switching state when switching on the first port NC essentially not the same potential as at the third port COM is present, a fault condition by means of a warning device W signaled. For example, in 1 an error condition by means of a warning device W in step 600 be signaled. Thereafter, depending on the application and configuration either as shown, the permanent connection be prevented or the connection is under warning (by the warning device W or after remote notification) and / or by explicit release (eg by means of confirmation by key T ) possible.

In a further embodiment of the invention, the warning device W a signal light and / or an acoustic warning device and / or a remote message FM on. Without limitation of generality, the warning device W also be combined with other facilities. Exemplary is in 5 shown that the warning device also together with a button T , For example, a light-emitting, can be realized.

Although the steps 300 and 400 separated and presented in chronological order, this need not be the case. Rather, the steps can be performed in any order as well as at the same time.

However, the timed sequence of steps has an advantage in that the mechanical switch S2 can preferably be switched load-free, so that, for example arcs, which can lead to a contact welding / bonding, can be avoided. For this purpose, the circuit breaker 1 in a further, intermediate switching state between the first switching state and the further switching state of the electronic switch S1 switch off to a currentless switching of the mechanical toggle switch S2 in working position. That is, before moving the mechanical changeover switch S2 in working position in step 300 can the electronic switch S1 first in step 250 be switched off to a currentless switching of the mechanical changeover switch S2 in working position.

Although the circuit breaker 1 has been described above only with reference to a switch-on, the circuit breaker 1 Similarly, when turned off on a bonding / welding out to be checked. This will be explained below. In this case, the methods for monitoring the switching on / off can basically be used independently of each other, in terms of time.

When switching off the circuit breaker 1 is in a first switching state, first the mechanical changeover switch S2 disabled. Now the first connection NC by means of the monitoring device Ü measured, whether at the first port NC essentially the same potential as at the third port COM is applied. If this is the case, in a subsequent further switching state, both the electronic switch S1 be deactivated as well as the mechanical changeover switch S2 are at rest.

That is, it is now possible to determine whether the changeover contact by checking the voltage at the first terminal compared to the third terminal COM the mechanical changeover switch S2 is glued, because it is now possible to determine whether the changer of S2 from the second port NO solved or not. This is accomplished by using a welded / glued changer on the first connector NC essentially a different potential than the third connection COM is applied.

A corresponding method will now be described on the basis of 2 be explained in the event of switching off. Ie in this procedure is checked before permanently switching off, whether the contact glued / welded, and thus the electrical isolation in the event of switching off is no longer given.

It is assumed that the circuit breaker 1 as previously configured. In a first step 1100 becomes the mechanical changeover switch S2 disabled. The following can be found in step 1200 by means of the monitoring device Ü be checked, whether at the first port NC essentially the same potential as at the third port COM is applied. If this is the case, both the electronic switch S1 in step 1400 be deactivated as well as the mechanical changeover switch S2 to be left at rest.

In one embodiment of the invention, if in the first switching state at the first terminal NC essentially not the same potential as at the third port COM is present, a fault condition by means of a warning device W , eg one step 1600 be signaled. The warning device W can be independent or the same warning device W as described above with respect to the power on. Furthermore, the circuit breaker 1 also have a remote message for this error case.

However, the timed sequence of steps has an advantage in that the mechanical switch S2 can preferably be switched load-free, so that, for example arcs, which can lead to a contact welding / bonding, can be avoided. For this purpose, the circuit breaker 1 before disabling 1100 of the mechanical changeover switch S2 the electronic switch S1 in an intermediate step 1050 be switched off to a currentless switching of the mechanical changeover switch S2 in working position.

Without limitation of generality, the circuit breaker 1 furthermore a fuse wire fuse F having the fuse wire fuse F in series with the electronic switch S1 and the third port COM of the mechanical changeover switch S2 is switched. This fuse F can be triggered eg in case of overload.

Furthermore, as in 4 indicated, the mechanical changeover switch S2 further comprising one or more mechanically coupled but electrically isolated switchable poles. That is, by monitoring at least one pole of the mechanical changeover switch S2 For a large number of mechanically coupled poles, the state with regard to galvanic isolation can also be determined. Of course, every single pole can be monitored separately.

That is, the invention makes use of the "normally closed" contact of the relay as a measuring input at certain times in order to query whether the electrical isolation is ensured. In case of error, eg overcurrent ( lout ) or an overvoltage Uin / Uout / Urel-check the user can be informed about the error case and / or the continued operation can be prevented.

If the user selects a channel from Uin to Uout by means of the circuit breaker (eg by pressing the key once T ), so first the electronic switch S1 be switched through and the "normally closed" contact NC of the mechanical switch S2 be measured, whether voltage is applied. If voltage is present, it can be concluded that the switching contact of the mechanical switch S2 not in the NO Position is welded. The electronic switch S1 can now be switched off and provided the mechanical switch S2 is faultless, the mechanical switch can S2 be switched on without power. Below is the electronic switch S1 be switched on and the output Uout is in operation (permanently until shutdown). When no voltage is applied, the electronic switch becomes S1 switched off and the user can be signaled that the output is not galvanically isolated (contact in the NO Welded position).

On the other hand, by means of the circuit breaker, a channel from Uin to Uout by the user (eg by pressing the key once T ) is switched off, then interrupts the electronic switch S1 the current flow. After that also the mechanical switch S2 (eg by the monitoring device U) off. In the next step, the electronic switch switches S1 again and the measurement is done on the "normally c | osed" contact NC , After that, the electronic switch S1 switched off again. If voltage was applied during measurement, the switch position on the mechanical switch has changed S2 took place and the galvanic isolation is ensured. In the event of an error, the user can be signaled that the output is not galvanically isolated (contact in the NO Welded position).

Without limitation of generality, the monitoring device Ü be provided in a variety of ways. For example, the monitoring device Ü be provided by a suitable microcontroller / microprocessor / FPGA / ASIC. In particular, the monitoring device Ü also a stream lout through the circuit breaker 1 but especially by the electronic switch S1 , to detect, for example, an overload case. Furthermore, the monitoring device can also provide a short-circuit monitoring.

The measuring input / inputs at the monitoring device U can be executed differently. The voltage can be measured via a voltage divider and the analog value further evaluated. Otherwise, the switching state can be digitally recorded and evaluated at a digital input.

In the event of a fault, suitable measures can be taken to indicate that the fault has occurred during switching on or off. For example, the telecommunications device FM Also be a digital interface that provides appropriate switch positions / error messages. At the same time, the telecommunications device FM be configured so that by means of the telecommunication device FM the circuit breaker 1 can also be controlled remotely.

LIST OF REFERENCE NUMBERS

1

breaker

F

Fuse wire fuse

Ü

monitoring device

NO

Normally open contact

NC

Normally Closed Contact

COM

Joint contact

T

button

FM

remote signaling

S1

Switch, electronic

S2

Switch, mechanical

W

warning device

Uin

Voltage at the entrance

Uout

Voltage at the output

Urel-check

Voltage at the output NC

relay-switch

Switching signal for mechanical switch

lout

Current through the circuit breaker

Claims (16)

Circuit breaker (1) with monitoring device (Ü) comprising an electronic switch (S1) and a mechanical changeover switch (S2), said mechanical changeover switch (S2) having a first port (NC), a second port (NO) and a third port (COM ), wherein in a rest position of the mechanical changeover switch (S2) the first connection (NC) is connected to the third connection (COM) and wherein in a working position of the mechanical changeover switch (S2) the second connection (NO) to the third connection ( COM) is connected, wherein the electronic switch (S1) to the third terminal (COM) of the mechanical changeover switch (S2) is connected as a series circuit, wherein upon activation of the circuit breaker (1) in a first switching state of the first electronic switch (S1) activated is, wherein at the first port (NC) by means of the monitoring device (Ü) is measured, whether at the first port (NC) substantially the same Pote ntial as at the third terminal (COM) is applied and if so, in a subsequent further switching state, both the electronic switch (S1) is activated and the mechanical changeover switch (S2) is in the working position. Circuit breaker (1) with monitoring device (Ü) after Claim 1 , characterized in that, if in the first switching state at the first terminal (NC) substantially not the same potential as at the third terminal (COM) is applied, an error condition by means of a warning device (W) is signaled. Circuit breaker (1) with monitoring device (Ü) after Claim 2 , characterized in that the warning device (W) has a signal light and / or an acoustic warning device and / or a remote message. Circuit breaker (1) with monitoring device (Ü) according to one of the preceding claims, characterized in that between the first switching state and the further switching state of the electronic switch (S1) is turned off to enable a currentless switching of the mechanical changeover switch (S2) in working position , Circuit breaker (1) with monitoring device (Ü) according to one of the preceding claims, characterized in that when switching off the circuit breaker (1) in a first switching state, first the mechanical changeover switch (S2) is deactivated, wherein at the first terminal (NC) by means of the monitoring device (Ü) is measured, whether at the first terminal (NC) substantially the same potential as at the third terminal (COM) is applied and if so, in a subsequent further switching state, both the electronic switch (S1) is deactivated as well mechanical changeover switch (S2) is in rest position. Circuit breaker (1) with monitoring device (Ü) after Claim 5 , characterized in that, if in the first switching state at the first terminal (NC) substantially not the same potential as at the third terminal (COM) is applied, an error condition by means of a warning device (W) is signaled. Circuit breaker (1) with monitoring device (Ü) after Claim 6 , characterized in that the warning device (W) has a signal light and / or an acoustic warning device and / or a remote message. Circuit breaker (1) with monitoring device (Ü) according to one of the preceding Claims 5 to 7 , characterized in that between the first switching state and the further switching state of the electronic switch (S1) is turned off to allow a currentless switching of the mechanical changeover switch (S2) in the working position. Circuit breaker (1) with monitoring device (Ü) according to one of the preceding claims, wherein the circuit breaker further comprises a fuse wire fuse (F), wherein the fuse wire fuse (F) in series with the electronic switch (S1) and the third terminal (COM) of the mechanical Changeover switch (S2) is switched. Circuit breaker (1) with monitoring device (Ü) according to one of the preceding claims, wherein the mechanical changeover switch (S2) further comprises one or more mechanically coupled, but electrically isolated switchable poles. Method for a circuit breaker (1) with monitoring device (Ü) comprising an electronic switch (S1) and a mechanical changeover switch (S2), wherein the mechanical changeover switch (S2) has a first connection (NC), a second connection (NO) and a third connection Connection (COM), wherein in a rest position of the mechanical changeover switch (S2) of the first terminal (NC) to the third terminal (COM) is connected, and wherein in a working position of the mechanical changeover switch (S2) of the second terminal (NO) with the third terminal (COM) is connected, wherein the electronic switch (S1) to the third terminal (COM) of the mechanical changeover switch (S2) is connected in series, comprising the steps when switching the circuit breaker (1) in a first switching state: Activating (100) the electronic switch (S1), Checking (200) by means of the monitoring device (Ü) whether substantially the same potential is present at the first connection (NC) as at the third connection (COM) and, if this is the case, activating both the electronic switch (S1) (400 ) as well as the mechanical changeover switch (S2) in working position spend (300). Method according to Claim 11 , characterized in that, if at the first terminal (NC) when switching substantially not the same potential as at the third terminal (COM) is applied, an error condition by means of a warning device (W) is signaled (600). Method according to one of the preceding Claims 11 or 12 , characterized in that before the introduction of the mechanical changeover switch (S2) in the working position (300) of the electronic switch (S1) is first turned off (250) to allow a currentless switching of the mechanical changeover switch (S2) in the working position. Method according to one of the preceding Claims 11 to 13 comprising the steps of switching off the circuit breaker (1): • deactivating (1100) the mechanical changeover switch (S2), • checking (1200) by means of the monitoring device (Ü), if at the first connection (NC) substantially the same potential as at third terminal (COM) is applied and, if so, both deactivate (1400) the electronic switch (S1) and leave the mechanical changeover switch (S2) in the neutral position. Method according to Claim 14 , characterized in that, if at the first terminal (NC) when switching off substantially not the same potential as at the third terminal (COM) is applied, an error condition by means of a warning device (W) is signaled (1600). Method according to Claim 14 or 15 , characterized in that before deactivating (1100) of the mechanical changeover switch (S2), the electronic switch (S1) is turned off (1050) to allow a currentless switching of the mechanical changeover switch (S2) in the working position.

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