DE102019214318B4 - protection switching system - Google Patents

Abstract

Protective switching system for a low-voltage circuit with a higher-level protective device (OSG) and at least one subordinate protective device (USGA), in which the subordinate protective device (USGA):- has a unique second identification number,- a voltage sensor (SU2) to determine the voltage level of the low-voltage circuit, - a current sensor (SI2) for determining the current level of the low-voltage circuit,- a communication unit (COM2), for wireless communication with the higher-level protection device (OSG),- one with the voltage sensor (SU2), the current sensor (SI2) and the communication unit ( COM2) connected control unit (SE2), which is designed in such a way that the: - subordinate voltage level (Vdown2) and the subordinate current level (Idown2) are determined regularly, - a subordinate current change value, which is the difference between two temporally consecutive determined current levels (Idwon2). , is determined - the subordinate Stro mheight (Idown2) and the current change value together with the second identification number is transmitted wirelessly by the communication unit (COM2), in which the higher-level protective device (OSG):- has a unique first identification number,- a voltage sensor (SU1) to determine the voltage level of the low-voltage circuit, - a current sensor (SI1) to determine the current level of the low-voltage circuit, - a communication unit (COM1), for wireless communication with the at least one subordinate protection device (USGA), - an internal or external interruption unit (UEE), to interrupt the low-voltage circuit ,- a control unit (SE1) connected to the voltage sensor (SU1), the current sensor (SI1), the communication unit (COM1) and the interruption unit (UEE), which is designed in such a way that the:- higher-level voltage level (Vup) and the superordinate current level (Iup) is determined - the determined superior assigned voltage level (Vup) is sent wirelessly by the communication unit (COM1) together with the unique first identification number, - a higher-level current change value, which is the difference between two chronologically consecutive higher-level current levels (Iup), is determined and this is compared with the received lower-level current change value , if they match, the identification number of this subordinate protective device (USGA) is stored in a positive list and a signal with the first identification number is sent to the subordinate protective device (USGA);- that the subordinate protective device (USGA) responds to the received signal with the superior protective device (OSG ) with the first identification number as its higher-level protection device (OSG) and compares the determined lower-level voltage level (Vdown2) with the received voltage level (Vup) of its higher-level protection device (OSG) and when a span is exceeded voltage difference value, an interruption signal with the second identification number is sent wirelessly via the communication unit (COM2);- that the higher-level protection device (OSG) upon receipt of an interruption signal initiates an interruption of the low-voltage circuit (L,N) only if the interruption signal is from a subordinate protection device ( USGA) comes with a whitelisted identification number.

Description

The invention relates to a protective switching system for a low-voltage circuit with a higher-level protective device and at least one lower-level protective device, and a method.

There are various protective devices for low-voltage electrical circuits. Low voltage means voltages of up to 1000 volts AC or 1500 volts DC. Low voltage also means voltages that are greater than extra-low voltage with values of 50 volts AC or 120 volts DC.
Low-voltage circuits are circuits with rated currents from 10 to 6300 amperes. Different protective devices are used depending on the magnitude of the rated current. For example, closed circuit breakers (compact circuit breakers, molded case circuit breaker—MCCB) are used for currents from 63 to 1600 amperes, in particular from 125 to 630 or 1200 amperes. Air circuit breakers (air circuit breakers, air circuit breaker - ACB) are used in particular for currents from 630 to 6300 amperes, more specifically from 1200 to 6300 amperes. Miniature circuit breakers are typically used for currents from 10 to 63 amps. Residual current circuit breakers are also known, which monitor the total current in the electrical circuit and interrupt the electrical circuit if the total current deviates. Furthermore, fire protection switches are known, also known as arc fault detection devices, which monitor the electrical circuit for arc faults and interrupt the circuit when they occur. AFD units are currently the most advanced protective devices. Many, but not all, faults in the circuit can be detected with the protective devices mentioned. For example, state-of-the-art protective devices fail in the presence of medium and high impedances or

Resistances in the circuit, in the presence of overheated or glowing connections in the circuit. A glowing connection is an electrical connection with high impedance: it is generally due to the oxidation of conductors and can reach a temperature of up to 1800°C.

In the German patent application DE 10 2015 209 663 A1 a novel system for detecting such errors is disclosed. This is characterized by a resistance determination, a calibration mode and a measurement mode.

In the American patent application U.S. 2016/0241017 A1 distributed arc protection between outlet and circuit breaker is disclosed. The disclosed methods and systems use a non-probability based detection scheme that measures conditions (eg, voltage or current) at multiple locations in a circuit, such as a consumer circuit, to detect the presence of an arcing fault condition. A centralized processing system such as B. a controller (120), receives information corresponding to a voltage or current measurement of a branch origin detected by a sensor (114, 116) at a branch origin upstream of the plurality of end-use devices (150) and receives information corresponding to a downstream voltage or current measurement at each of the terminals sensed by a corresponding downstream sensor (152, 154).

In the American patent application US2016/0329700A1 a system for detecting a falling electrical power conductor and a related method is disclosed. Methods and systems for detecting a falling power line in a power transmission or distribution system are described. Electrical measurements at various points in the power distribution system are used to detect changes in a power line that indicate that the conductor has been broken or disconnected. Upon detection, control mechanisms are used to shut off the conductor while the conductor is falling and/or before it hits the ground.

The object of the present invention is to specify a simple system, protective device and method for detecting such faults, in particular to specify an automatic configuration of such a protective switching system or protective devices.

This object is achieved by a protective switching system having the features of patent claim 1, a higher-level protective device according to patent claim 11, at least one subordinate protective device according to patent claim 13 or a method according to patent claim 14.

• 1.a) Ein untergeordnetes Schutzgerät mit:
  • - einer eineindeutigen zweiten Identifikationsnummer (eine untergeordnete Identifikationsnummer), wobei jedes untergeordnete Schutzgerät eine eigene (unterschiedliche) eineindeutige Identifikationsnummer aufweist,
  • - einen Spannungssensor, zur Ermittlung der (lokalen, untergeordneten) Spannungshöhe des Niederspannungsstromkreises (am untergeordneten Schutzgerät),
  • - einen Stromsensor, zur Ermittlung der (lokalen, untergeordneten) Stromhöhe des Niederspannungsstromkreises (am untergeordneten Schutzgerät),
  • - eine Kommunikationseinheit, zur drahtlosen Kommunikation mit dem übergeordnetem Schutzgerät,
  • - eine mit dem Spannungssensor, dem Stromsensor und der Kommunikationseinheit verbundenen Steuereinheit, die derart ausgestaltet ist, dass regelmäßig die:
  • - untergeordnete Spannungshöhe und die untergeordnete Stromhöhe ermittelt wird,
  • - ein untergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender ermittelter Stromhöhen ist, beispielsweise mit einem ersten zeitlichen Abstand, z.B. 100 ms, ermittelt wird,
  • - die untergeordnete Stromhöhe und der Stromänderungswert zusammen mit der zweiten Identifikationsnummer (bzw. der jeweiligen Identifikationsnummer des jeweiligen untergeordneten Schutzgerätes) drahtlos durch die Kommunikationseinheit ausgesendet wird, so dass sie vom übergeordneten Schutzgerät empfangen werden kann.
• 2.a) Ein übergeordnetes Schutzgerät mit:
  • - einer eineindeutigen ersten Identifikationsnummer (übergeordnete Identifikationsnummer),
  • - einem Spannungssensor, zur Ermittlung der (lokalen, übergeordneten) Spannungshöhe des Niederspannungsstromkreises (am übergeordneten Schutzgerät),
  • - einem Stromsensor, zur Ermittlung der (lokalen, übergeordneten) Stromhöhe des Niederspannungsstromkreises (am übergeordneten Schutzgerät),
  • - einer Kommunikationseinheit, zur drahtlosen Kommunikation mit dem mindestens einem untergeordnetem Schutzgerät,
  • - einer internen oder externen Unterbrechungseinheit, zur Unterbrechung des Niederspannungsstromkreises,
  • - eine mit dem Spannungssensor, dem Stromsensor, der Kommunikationseinheit und der Unterbrechungseinheit verbundenen Steuereinheit, die derart ausgestaltet ist, dass regelmäßig die:
  • - übergeordnete Spannungshöhe und die übergeordnete Stromhöhe ermittelt wird,
  • - die ermittelte übergeordnete Spannungshöhe zusammen mit der eineindeutigen ersten Identifikationsnummer drahtlos durch die Kommunikationseinheit ausgesendet wird, so dass sie von dem untergeordneten Schutzgerät(en) empfangen werden kann,
  • - ein übergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender übergeordneter Stromhöhen ist, ermittelt und der empfangenen untergeordnete Stromänderungswert mit dem übergeordneten Stromänderungswert vergleichen wird, bei Übereinstimmung die zweite Identifikationsnummer (die Identifikationsnummer des untergeordneten Schutzgerätes des empfangenen Stromänderungswertes) in einer Positivliste gespeichert wird und ein Signal mit der ersten Identifikationsnummer an das untergeordnete Schutzgerät gesendet wird.
• 1.b) Dass das untergeordnete Schutzgerät:
  • - auf das empfangene Signal das übergeordnete Schutzgerät mit der ersten Identifikationsnummer als sein übergeordnetes Schutzgerät speichert und die ermittelte untergeordnete Spannungshöhe mit der empfangenen Spannungshöhe seines übergeordneten Schutzgerätes vergleicht und bei Überschreitung eines Spannungsdifferenzwertes ein Unterbrechungssignal mit seiner (der zweiten) Identifikationsnummer über die Kommunikationseinheit drahtlos aussendet, so dass es vom übergeordneten Schutzgerät empfangen werden kann.
• 2.b) Dass die übergeordnete Schutzeinheit:
  • - bei Empfang eines Unterbrechungssignals eine Unterbrechung des Niederspannungsstromkreises nur dann initiiert, wenn das Unterbrechungssignal von einem untergeordneten Schutzgerät mit einer in der Positivliste enthaltenen Identifikationsnummer kommt.

According to the invention, a protective switching system for a low-voltage circuit is provided with a higher-level protective device and at least one lower-level protective device, which has the following:

• 1.a) A sub-protection device with:
  • - a unique second identification number (a sub-identification number), each sub-protection device having its own (different) unique identification number,
  • - a voltage sensor, to determine the (local, subordinate) voltage level of the low-voltage circuit (on the subordinate protection device),
  • - a current sensor, for determining the (local, subordinate) current level of the low-voltage circuit (on the subordinate protection device),
  • - a communication unit for wireless communication with the higher-level protection device,
  • - a control unit connected to the voltage sensor, the current sensor and the communication unit, which is designed in such a way that regularly the:
  • - the subordinate voltage level and the subordinate current level are determined,
  • - a subordinate current change value, which is the difference between two temporally consecutive determined current levels, for example with a first time interval, for example 100 ms, is determined,
  • - the subordinate current level and the current change value together with the second identification number (or the respective identification number of the respective subordinate protective device) is transmitted wirelessly by the communication unit so that it can be received by the higher-level protective device.
• 2.a) A parent protection device with:
  • - a unique first identification number (superordinate identification number),
  • - a voltage sensor to determine the (local, higher-level) voltage level of the low-voltage circuit (at the higher-level protective device),
  • - a current sensor to determine the (local, higher-level) current level of the low-voltage circuit (on the higher-level protective device),
  • - a communication unit for wireless communication with the at least one subordinate protection device,
  • - an internal or external interrupting unit, for interrupting the low-voltage circuit,
  • - a control unit connected to the voltage sensor, the current sensor, the communication unit and the interruption unit, which is designed in such a way that regularly the:
  • - the higher-level voltage level and the higher-level current level are determined,
  • - the determined higher-level voltage level is transmitted wirelessly by the communication unit together with the unique first identification number, so that it can be received by the lower-level protective device(s),
  • - a higher-level current change value, which is the difference between two chronologically consecutive higher-level current levels, is determined and the received lower-level current change value is compared with the higher-level current change value, if they match, the second identification number (the identification number of the lower-level protection device of the received current change value) is saved in a positive list and a signal with the first identification number is sent to the subordinate protection device.
• 1.b) That the secondary protection device:
  • - on the received signal, the higher-level protective device with the first identification number saves as its higher-level protective device and compares the determined subordinate voltage level with the received voltage level of its higher-level protective device and, if a voltage difference value is exceeded, wirelessly transmits an interrupt signal with its (the second) identification number via the communication unit, so that it can be received by the higher-level protection device.
• 2.b) That the overriding protection unit:
  • - upon receipt of an interrupt signal, initiates an interrupt of the low-voltage circuit only if the interrupt signal comes from a subordinate protection device with an identification number included in the whitelist.

This has the advantage that specific faults in the circuit, such as medium and large impedances or resistances or overheated or glowing connections in the circuit, can be detected, with the devices required for detection being configured automatically.

Advantageous configurations are specified in the dependent claims.

In an advantageous embodiment of the invention, the external interruption unit is a circuit breaker, circuit breaker, fault current circuit breaker or fire protection switch, which is mechanically or electrically coupled to the higher-level protective device.

This has the particular advantage that protective devices that are already known and reliable and that are present in low-voltage circuits can be used, which can only be coupled to the new, higher-level protective device according to the invention.
Alternatively, the higher-level protective device or its function can also be integrated in the line circuit breaker, circuit breaker, residual current circuit breaker or fire protection switch.
Alternatively, an interrupting unit of a circuit breaker, circuit breaker, fault current circuit breaker or fire protection switch can be provided in the higher-level protective device.

In an advantageous embodiment of the invention, the subordinate protective device is arranged in or on an electrical consumer of the low-voltage circuit,
designed as an adapter for the low-voltage circuit or
located in a power strip for a low voltage circuit.
This has the particular advantage that the invention can be used easily (also subsequently) in existing low-voltage circuits.

In an advantageous embodiment of the invention, the voltage difference value is greater than 13 volts, in particular greater than 20 volts.
This has the particular advantage that a reliable limit value has been found above which problematic voltage drops in the low-voltage circuit occur, at which an interruption should occur.

In an advantageous embodiment of the invention, upon receipt of the interruption signal by the higher-level protective device, this initiates a delayed interruption depending on the magnitude of the current in the low-voltage circuit, such that a timely interruption occurs at high currents and a delayed interruption at low currents. This has the particular advantage that an error can be observed or verified even more closely, depending on the severity or the potential for destruction, before an interruption occurs.
Delay sides depending on the current level could be about: 2 s for 1 A (current level); 1s for 2A; 0.5s for 4A; 0.25s for 8A; 0.1s for 16A or more.

In an advantageous embodiment of the invention, the higher-level current change value is compared with the received lower-level current change value in a time window with a first time interval.
This has the particular advantage that a subordinate protective device can be precisely assigned to a higher-level protective device in an environment with several protective devices or protective switching systems.
The time window can be in the range of 50 ms to 1 s, in particular 50 to 500 ms, more specifically 60 to 200 ms, or approximately 100 ms. The current change values are ideally identical and can practically deviate in the range of +/-20% within the same time window of around 100 ms, for example.

In an advantageous embodiment of the invention, a repeated current change in the low-voltage circuit is initiated when the subordinate protective device is put into operation. This has the particular advantage that it enables the respective subordinate protection device to be assigned to the higher-level protection device quickly and easily. For example, by successively initiating such a multiple current change for all subordinate protection devices. Alternatively or additionally, several “positive” events (change in current value change within the time window) can be provided in order to cause the identification number to be included in the positive list. Alternatively or additionally, a “negative” event can lead to the identification number being removed from the positive list.

In an advantageous embodiment of the invention, each or some of the transmissions contain a time stamp, in particular with the current time or additionally with the date or with a relative or absolute time specification.
This has the particular advantage that an exact assignment and comparison of the values contained, in particular current change values, is made possible, so that an exact assignment of the respective lower-level protective device to the higher-level protective device is made possible.

In an advantageous embodiment of the invention, there is no interruption if the current level is less than a current threshold value. In particular, the current threshold value can be less than 0.5 amperes or the power can be less than 100 W.
This has the particular advantage that there is no interruption in non-critical situations.

According to the invention, a higher-level protective device, a lower-level protective device and a method for a low-voltage circuit are also claimed.

All configurations, both in dependent form referring back to patent claim 1, 11, 13 or 14, as well as referring back only to individual features or combinations of features of patent claims, in particular also subclaims 2 to 10 based on independent claims 11, 13, 14 an improvement in a protective switching system, protective devices or a method for detecting and switching off the errors mentioned at the outset.

The characteristics, features and advantages of this invention described and the manner in which they are achieved will become clearer and more clearly understood in connection with the following description of the exemplary embodiments, which are explained in more detail in connection with the drawing.

• 1 ein erstes Schaltbild zur Erläuterung der Erfindung,
• 2 einen angedeuteten Stromkreis zur Erläuterung der Erfindung.

The drawing shows:

• 1 a first circuit diagram to explain the invention,
• 2 an indicated circuit to explain the invention.

1 shows a low-voltage circuit with a phase conductor L and a neutral conductor N, which go through a higher-level protection device OSG to an external interruption unit UEE with contacts K1, K2. From there they go to a branch, to which two subordinate protection devices USGA, USGB with an integrated load LOADA, LOADB are connected.

• - eine eineindeutige erste (übergeordnete) Identifikationsnummer,
• - einen (ersten) Spannungssensor SU1, zur Ermittlung der Spannungshöhe des Niederspannungsstromkreises, d.h. der Leiter L, N,
• - einen (ersten) Stromsensor SI1, zur Ermittlung der Stromhöhe des Niederspannungsstromkreises, im Beispiel des Phasenleiters L,
• - eine (erste) Kommunikationseinheit COM1, zur drahtlosen Kommunikation,
• - eine mit dem (ersten) Spannungssensor SU1, dem (ersten) Stromsensor SI1, der (ersten) Kommunikationseinheit COM1 verbundene (erste) Steuereinheit SE1 auf.

Ferner ist das übergeordnete Schutzgerät OSG bzw. dessen Steuereinheit SE1 mit der externen Unterbrechungseinheit UEE verbunden, die Kontakte K1, K2 zur Unterbrechung der Leiter L, N des Niederspannungsstromkreises aufweist.
Die Unterbrechungseinheit UEE könnte auch im übergeordneten Schutzgerät OSG integriert sein.The higher-level protective device OSG has:

• - a unique first (superordinate) identification number,
• - a (first) voltage sensor SU1, for determining the voltage level of the low-voltage circuit, ie the conductors L, N,
• - a (first) current sensor SI1, for determining the current level of the low-voltage circuit, in the example of the phase conductor L,
• - a (first) communication unit COM1 for wireless communication,
• - a (first) control unit SE1 connected to the (first) voltage sensor SU1, the (first) current sensor SI1, the (first) communication unit COM1.

Furthermore, the higher-level protective device OSG or its control unit SE1 is connected to the external interruption unit UEE, which has contacts K1, K2 for interrupting the conductors L, N of the low-voltage circuit.
The interruption unit UEE could also be integrated in the higher-level protective device OSG.

• - übergeordnete Spannungshöhe Vup und die übergeordnete Stromhöhe Iup ermittelt wird,
• - die ermittelte übergeordnete Spannungshöhe Vup zusammen mit der eineindeutigen (ersten, übergeordneten) Identifikationsnummer des übergeordneten Schutzgerätes OSG drahtlos durch die (erste) Kommunikationseinheit COM1 ausgesendet wird,
• - die übergeordnete Stromhöhe Iup und ein übergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender Stromhöhen Iup ist, wird ermittelt. Der Stromänderungswert kann beispielsweise aus zwei Stromhöhen ermittelt werden, die einen ersten zeitlichen Abstand aufweisen. Beispielsweise kann dieser erste zeitliche Abstand zwischen 40 und 400 ms betragen. Beispielsweise 100 ms.

Der übergeordnete Stromänderungswert wird mit durch die Kommunikationseinheit COM1 empfangenen untergeordneten Stromänderungswerten eines untergeordneten Schutzgerätes, wie beispielsweise des untergeordneten Schutzgerätes USGA, USGB verglichen, bei Übereinstimmung wird die eineindeutige Identifikationsnummer des untergeordneten Schutzgerätes USGA, USGB in einer Positivliste des übergeordneten Schutzgerätes OSG gespeichert und ein Signal vom übergeordneten Schutzgerätes OSG mit der ersten / übergeordneten Identifikationsnummer an dieses untergeordnete Schutzgerät USGA, USGB gesendet.
Bei Empfang eines Unterbrechungssignals am übergeordneten Schutzgerät OSG wird eine Unterbrechung des Niederspannungsstromkreises mittels der Unterbrechungseinheit UEE nur dann initiiert, wenn das Unterbrechungssignal von einem untergeordneten Schutzgerät USGA, USGB mit einer in der Positivliste enthaltenen Identifikationsnummer kommt.Depending on the rated current of the low-voltage circuit, the UEE could be a miniature circuit breaker (MCB), circuit breaker (CB, MCCB, ACB), residual current device (RCD), arc fault detection device (AFDD) or other protective switching device.
The (first) control unit SE1 is designed in such a way that the:

• - the overriding voltage level Vup and the overriding current level Iup are determined,
• - the determined higher-level voltage level Vup together with the one-to-one (first, higher-level) identification number of the higher-level protective device OSG is transmitted wirelessly through the (first) communication unit COM1,
• - The higher-level current level Iup and a higher-level current change value, which is the difference between two successive current levels Iup, is determined. The current change value can be determined, for example, from two current levels that have a first time interval. For example, this first time interval can be between 40 and 400 ms. For example 100ms.

The higher-level current change value is compared with the lower-level current change values of a lower-level protection device, such as the lower-level protection device USGA, USGB, received by the communication unit COM1 higher-level protection device OSG with the first / higher-level identification number to this sub-protection device USGA, USGB.
When an interruption signal is received at the higher-level protection device OSG, the low-voltage circuit is only interrupted by the interruption unit UEE if the interruption signal comes from a subordinate protection device USGA, USGB with an identification number contained in the positive list.

• - einen (zweiten) Spannungssensor SU2, zur Ermittlung der Spannungshöhe Vdown2 des (dortigen Teiles des) Niederspannungsstromkreises,
• - einen (zweiten) Stromsensor SI2, zur Ermittlung der Stromhöhe Idown2 des (dortigen Teiles des) Niederspannungsstromkreises,
• - eine (zweite) Kommunikationseinheit COM2, zur drahtlosen Kommunikation,
• - eine mit dem (zweiten) Spannungssensor SU2, dem (zweiten) Stromsensor SI2 und der (zweiten) Kommunikationseinheit COM2 verbundenen (zweiten) Steuereinheit SE2 auf.

The USGA slave protection device has a unique second (slave) identification number. The third/further subordinate protection device USGB has a unique third (subordinate) identification number. Each further slave protection device would have another unique fourth, fifth, ... (slave) identification number.
The subordinate protection device USGA has:

• - a (second) voltage sensor SU2, for determining the voltage level Vdown2 of the (part of) the low-voltage circuit,
• - a (second) current sensor SI2, for determining the current level Idown2 of the (part of) the low-voltage circuit,
• - a (second) communication unit COM2, for wireless communication,
• - a (second) control unit SE2 connected to the (second) voltage sensor SU2, the (second) current sensor SI2 and the (second) communication unit COM2.

• - einen (dritten) Spannungssensor SU3, zur Ermittlung der Spannungshöhe Vdown1 des (dortigen Teiles des) Niederspannungsstromkreises,
• - einen (dritten) Stromsensor SI3, zur Ermittlung der Stromhöhe Idown1 des (dortigen Teiles des) Niederspannungsstromkreises,
• - eine (dritte) Kommunikationseinheit COM3, zur drahtlosen Kommunikation,
• - eine mit dem (dritten) Spannungssensor SU3, dem (dritten) Stromsensor SI3 und der (dritten) Kommunikationseinheit COM3 verbundenen (dritte) Steuereinheit SE3 auf.

Similarly, the third/further subordinate protection device USGB:

• - a (third) voltage sensor SU3, for determining the voltage level Vdown1 of the (part of) the low-voltage circuit,
• - a (third) current sensor SI3, for determining the current level Idown1 of the (part of) the low-voltage circuit,
• - a (third) communication unit COM3, for wireless communication,
• - a (third) control unit SE3 connected to the (third) voltage sensor SU3, the (third) current sensor SI3 and the (third) communication unit COM3.

Each additional subordinate protection device is constructed in a similar way.

• - untergeordnete Spannungshöhe Vdown2 (Vdown1) und die untergeordnete Stromhöhe Idown2 (Idown1) ermittelt wird,
• - ein untergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender ermittelter Stromhöhen Idown2 (Idown1) ist, ermittelt wird, die einen ersten zeitlichen Abstand aufweisen. Beispielsweise kann dieser erste zeitliche Abstand zwischen 40 und 400 ms betragen. Beispielsweise 100 ms. In einer Ausgestaltung kann der gleiche zeitliche Abstand wie beim übergeordneten Schutzgerät verwendet werden.,
• - die untergeordnete Stromhöhe Idown2 und der Stromänderungswert zusammen mit der zweiten (dritten) Identifikationsnummer drahtlos durch die Kommunikationseinheit COM2 (COM3) ausgesendet wird.

Sendet das übergeordnete Schutzgerät OSG ein Signal mit dessen erster/übergeordneter Identifikationsnummer an das untergeordnete Schutzgerät USGA (USGB) mit dessen zweiter/untergeordneter (dritter) Identifikationsnummer, was durch die Kommunikationseinheit COM2 (COM3) empfangen wird, so wird das übergeordnete Schutzgerät OSG als sein übergeordnetes Schutzgerät im untergeordneten Schutzgerät USGA (USGB) gespeichert.The subordinate protective device USGA (USGB) or its control unit SE2 (SE3) is designed in such a way that the:

• - the subordinate voltage level Vdown2 (Vdown1) and the subordinate current level Idown2 (Idown1) are determined,
• - a subordinate current change value is determined, which is the difference between two temporally successive determined current levels Idown2 (Idown1) which have a first time interval. For example, this first time interval can be between 40 and 400 ms. For example 100ms. In one embodiment, the same time interval can be used as for the higher-level protection device.,
• - the subordinate current level Idown2 and the current change value together with the second (third) identification number is transmitted wirelessly through the communication unit COM2 (COM3).

If the superior protective device OSG sends a signal with its first/major identification number to the subordinate protective device USGA (USGB) with its second/subordinate (third) identification number, which is received through the communication unit COM2 (COM3), then the superior protective device OSG will be as Parent protection device stored in child protection device USGA (USGB).

The subordinate protective device USGA (USGB) or its control unit SE2 (SE3) compares [at the latest from then or thereafter] the higher-level voltage level (Vup) of its higher-level protective device OSG received by the communication unit COM2 (COM3) with the determined lower-level [own] voltage level Vdonw2 (Vdonw1). If a voltage difference value is exceeded, an interruption signal with the [own subordinate] second (third) identification number is wirelessly transmitted via the communication unit.

In the example according to 1 Both subordinate protection devices USGA, USGB should be included in the positive list, since both belong to the circuit of the higher-level protection device OSG. Changes in current at the subordinate protective devices USGA, USGB cause (simultaneous or real-time) current changes at the higher-level protective device OSG, so that the invention (automatically) recognizes both subordinate protective devices USGA, USGB as belonging to its circuit.

• - eine untergeordnete (zweite) Spannungshöhe Vdown2 und eine untergeordnete (zweite) Stromhöhe Idown2 wird durch das untergeordnete (zweite) Schutzgerät USGA ermittelt,
• - ein untergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender ermittelter (zweiter) Stromhöhen Idown2 ist, wird durch das untergeordnete Schutzgerät USGA ermittelt,
• - die untergeordnete (zweite) Stromhöhe Idown2 und der untergeordnete (zweite) Stromänderungswert zusammen mit einer untergeordneten (zweiten) Identifikationsnummer wird drahtlos mittels der (zweiten) Kommunikationseinheit COM2 durch das untergeordnete (zweite) Schutzgerät USGA ausgesendet;
• - eine übergeordnete Spannungshöhe Vup und eine übergeordnete Stromhöhe (Iup) wird durch das übergeordnete Schutzgerät OSG ermittelt,
• - die ermittelte übergeordnete Spannungshöhe (Vup) zusammen mit einer übergeordneten/ersten Identifikationsnummer wird drahtlos mittels der (ersten) Kommunikationseinheit COM1 durch das übergeordnete Schutzgerät OSG ausgesendet,
• - die übergeordnete Stromhöhe Iup und ein übergeordneter Stromänderungswert, der die Differenz zweier zeitlich aufeinanderfolgender Stromhöhen Iup ist, wird durch das übergeordnete Schutzgerät OSG ermittelt,
• - der empfangene untergeordnete Stromänderungswert des untergeordneten (zweiten) Schutzgerätes USGA wird mit dem übergeordneten Stromänderungswert im übergeordneten Schutzgerät OSG verglichen, bei Übereinstimmung wird die untergeordnete/zweite Identifikationsnummer in einer Positivliste des übergeordneten Schutzgerätes OSG gespeichert und ein Signal mit der übergeordneten/ersten Identifikationsnummer mittels der (ersten) Kommunikationseinheit COM1 vom übergeordneten Schutzgerät OSG an das untergeordnete (zweite) Schutzgerät USGA gesendet,
• - dass das untergeordnete (zweite) Schutzgerät USGA auf das empfangene Signal das übergeordnete Schutzgerät OSG mit der übergeordneten/ersten Identifikationsnummer als sein übergeordnetes Schutzgerät OSG speichert und die ermittelte untergeordnete (zweite) Spannungshöhe Vdown2 mit der empfangenen übergeordneten Spannungshöhe Vup seines übergeordneten Schutzgerätes OSG vergleicht und bei Überschreitung eines Spannungsdifferenzwertes ein Unterbrechungssignal mit der untergeordneten/zweiten Identifikationsnummer über die Kommunikationseinheit OCM2 drahtlos aussendet (an das übergeordnete Schutzgerät OSG),
• - dass das übergeordnete Schutzgerät OSG bei Empfang eines(dieses) Unterbrechungssignals eine Unterbrechung des Niederspannungsstromkreises nur dann initiiert, wenn das Unterbrechungssignal von einem untergeordneten Schutzgerät USGA mit einer in der Positivliste enthaltenen Identifikationsnummer kommt. Dies sollte im Beispiel gemäß 1 erfüllt sein.

The procedure follows, for example, as follows:

• - a subordinate (second) voltage level Vdown2 and a subordinate (second) current level Idown2 is determined by the subordinate (second) protection device USGA,
• - a lower-level current change value, which is the difference between two consecutively determined (second) current levels Idown2, is determined by the lower-level protection device USGA,
• - the subordinate (second) current level Idown2 and the subordinate (second) current change value together with a subordinate (second) identification number is sent wirelessly by means of the (second) communication unit COM2 through the subordinate (second) protection device USGA;
• - a higher-level voltage level Vup and a higher-level current level (Iup) is determined by the higher-level protective device OSG,
• - the determined overriding voltage level (Vup) together with an overriding/ers th identification number is transmitted wirelessly by the higher-level protection device OSG using the (first) communication unit COM1,
• - the higher-level current level Iup and a higher-level current change value, which is the difference between two consecutive current levels Iup, is determined by the higher-level protective device OSG,
• - the received lower-level current change value of the lower-level (second) protection device USGA is compared with the higher-level current change value in the higher-level protection device OSG (first) communication unit COM1 sent from the higher-level protection device OSG to the subordinate (second) protection device USGA,
• - that the subordinate (second) protective device USGA stores the higher-level protective device OSG with the higher-level/first identification number as its higher-level protective device OSG on the received signal and compares the determined lower-level (second) voltage level Vdown2 with the received higher-level voltage level Vup of its higher-level protective device OSG and if a voltage difference value is exceeded, wirelessly transmits an interruption signal with the subordinate/second identification number via the OCM2 communication unit (to the higher-level protective device OSG),
• - that the master protective device OSG, upon receipt of a (this) interrupt signal, initiates a break of the low-voltage circuit only if the interrupt signal comes from a slave protective device USGA with an identification number included in the whitelist. This should be in accordance with the example 1 be fulfilled.

According to 1 a fault with a fault voltage Vfault is drawn in the branch to the subordinate protection device USGA. This would be recognized by the method according to the invention.

In the example according to 1 the subordinate protective devices USGA, USGB have an electrical consumer LOADA, LOADB or is arranged in them. Alternatively, the subordinate protective device can be designed as an intermediate plug. Alternatively, the sub-protective device may be located in a power strip or socket.

In the following, the invention will be explained further and advantages will be pointed out.

The higher-level protective device OSG can be designed as a so-called panel device, ie it can be arranged in a distribution. The overriding voltage Vup and the overriding current Iup flowing to the circuit are measured. Both measured values can be digitized by the (first) control unit SE1. An evaluation can also be carried out.
A (first) communication unit COM1 is connected to the (first) control unit SE1 in order to send and receive data. The (first) control unit SE1 can interrupt the circuit by means of the interruption unit UEE in the event of a detected error, ie open the contacts K1, K2.

The higher-level protective device OSG uses the (first) communication unit COM1 to send the higher-level actual voltage value Vup to all the lower-level protective devices USGA, USGB that are located downstream in the circuit. The subordinate protective devices can be integrated into consumers, for example at the input connection of a consumer device, such as 1 with included.

The subordinate protection devices USGA, USGB measure the incoming current Idown and the local voltage Vdown. The local voltage is compared to the voltage Vup on the overriding protection device OSG and when the difference ΔV exceeds a certain threshold value VTH, eg during a time window with a first period of time, an interrupt signal (trip signal) is sent to the overriding protection device. This period of time can be, for example, between 40 and 500 ms, in particular between 40 and 200 ms, for example approximately 50 ms.
Then the higher-level protection device OSG triggers an interruption of the circuit.

The measurement of the current level Iup in the higher-level protective device OSG can be used to interrupt the circuit quickly or without delay in the event of a high current Iup. If the current Iup is low, a time delay for the interruption can be provided.
Delay sides depending on the current level could be about: 2 s for 1 A (current level); 1s for 2A; 0.5s for 4A; 0.25s for 8A; 0.1s for 16A or more.

If several protective switching systems are in use, the higher-level protective devices OSG must support the subordinate protective devices USGA, Know or identify USGB that are part of their circuit.
Typically, pairing between two devices requires a user to press a pairing button on the parent device and then, within a defined time, a pairing button on the slave device to establish pairing.

With the current measurement according to the invention in the subordinate protective device USGA, USGB and transmission of the current values/changes to all higher-level protective devices OSG, these can recognize their subordinate protective devices USGA, USGB when consumers LOADA, LOADB are switched on or off or when there are power changes.

Each higher-level protective device OSG compares the current change measured and transmitted in the lower-level protective device USGA, USGB with the current change measured in the last time window (in the last time round), i.e. within a first period of time, in the higher-level protective device (with its own current sensor). If the value (and time period) matches for the parent device, then the slave device belongs to its circuit that is told about this, so that it can evaluate the correct voltage values of its parent device.

This is referred to as a pairing event and the identification number of the subordinate protection device is entered or saved in a positive list.

Higher-level protective devices that do not recognize a suitable current change in a lower-level protective device can exclude this from their circuit group and, for example, enter or save this identification number in a negative list. This is called a non-pairing event.

Advantageously, multiple pairing or non-pairing events may be used or required to pair or unpair protection devices. A larger number of events increases the security for pairing or unpairing. After a sufficient number of operations on the devices and identification, there is a reliable pairing. With each change in current, the correct pairing can advantageously be checked to ensure that a device has not been moved to a different circuit.

When the subordinate protective device is commissioned, a repeated current change in the low-voltage circuit, for example at the consumer LOADA, LOADB, can be initiated in order to achieve safe coupling.

The exchange of time stamps or the exact time synchronization in the transmissions / transmitted signals or communication messages can also be implemented in order to increase the accuracy / certainty of attribution of change events and a more reliable distinction between pairing and non-pairing.

The accuracy of the current sensors can also be increased in order to achieve greater reliability of the pairing processes through more precise current measurement and the associated determination of changes in the current value.

If only some of the loads in a circuit are supplemented by (subordinate) protective devices according to the invention, a protective effect can also be achieved according to the invention.

2 shows an outlined circuit (circuit) protected by the overriding protective device OSG. The circuit has several consumers 11, 12, 13 and 14. In this case, only the consumer 13 is protected by a subordinate protective device (not shown). In this case, the electrical lines a, b, c and h of the circuit are also protected.
The other lines or sections d, g and f are unprotected (as long as consumers 11, 12 and 14 are not expanded by subordinate protection devices according to the invention).

Thus, according to the invention, a circuit can be gradually expanded with the protective devices according to the invention in order to increase safety.

In one embodiment, the protective device(s) can have a power limit or current limit. At low power, the current value is low and the problem at the fault location is very low. There is no risk of electrical fire and detection is not (or not immediately) required. For example, a minimum value for the power would be 100 W or a current in the range of 0.5 A.

The currents of many small devices can add up in a common conductor and exceed the limit of 0.5 A, for example when connecting many devices to an extension cord with several sockets or a socket strip. In this case it would make sense to have a superordinate to integrate a protective device in the extension cable or in a socket strip

The subordinate protective device is advantageously integrated directly in the load (device), preferably at the input connection. The entire electrical installation and wiring is thus protected by the protective switching system from the higher-level protective device to the consumers.

The coupling between higher-level and lower-level protection devices is established automatically.
Nothing needs to be set up manually.
Newly installed or added protective devices can be automatically recognized and assigned. This is also automatically detected when protected devices are reassigned to other circuits with other higher-level protection devices.

The protective device according to the invention can be designed as a module, an independent device, for example for plugging into a socket, or integrated into a socket or other device.

Although the invention has been illustrated and described in more detail by the exemplary embodiment, the invention is not limited by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the protective scope of the invention.

Claims (14)

Protection switching system for a low-voltage circuit with a higher-level protective device (OSG) and at least one lower-level protective device (USGA), in which the lower-level protective device (USGA): - has a unique second identification number, - a voltage sensor (SU2), to determine the voltage level of the low-voltage circuit, - a current sensor (SI2) to determine the current level of the low-voltage circuit, - a communication unit (COM2) for wireless communication with the higher-level protection device (OSG), - a control unit (SE2) connected to the voltage sensor (SU2), the current sensor (SI2) and the communication unit (COM2), which is designed in such a way that the: - the subordinate voltage level (Vdown2) and the subordinate current level (Idown2) are determined, - a subordinate current change value, which is the difference between two temporally consecutive determined current levels (Idwon2), is determined, - the subordinate current level (Idown2) and the current change value together with the second identification number is transmitted wirelessly through the communication unit (COM2), where the higher-level protection device (OSG): - has a unique first identification number, - a voltage sensor (SU1), to determine the voltage level of the low-voltage circuit, - a current sensor (SI1) to determine the current level of the low-voltage circuit, - a communication unit (COM1) for wireless communication with the at least one subordinate protection device (USGA), - an internal or external interrupting unit (UEE), for interrupting the low-voltage circuit, - a control unit (SE1) connected to the voltage sensor (SU1), the current sensor (SI1), the communication unit (COM1) and the interruption unit (UEE), which is designed in such a way that the: - the overriding voltage level (Vup) and the overriding current level (Iup) are determined, - the determined overriding voltage level (Vup) is transmitted wirelessly by the communication unit (COM1) together with the unique first identification number, - a higher-level current change value, which is the difference between two chronologically consecutive higher-level current levels (Iup), is determined and this is compared with the received lower-level current change value, if they match, the identification number of this lower-level protection device (USGA) is saved in a positive list and a signal with the first identification number is sent to the subordinate protection device (USGA); - that the subordinate protection device (USGA) stores the higher-level protection device (OSG) with the first identification number as its higher-level protection device (OSG) on the received signal and the determined subordinate voltage level (Vdown2) with the received voltage level (Vup) of its higher-level protection device (OSG ) compares and when a voltage difference value is exceeded, an interruption signal with the second identification number is transmitted wirelessly via the communication unit (COM2); - that the higher-level protective device (OSG), upon receipt of a break signal, initiates a break of the low-voltage circuit (L,N) only if the break signal comes from a subordinate protective device (USGA) with an identification number included in the whitelist. protection switching system Claim 1 , characterized in that a further subordinate protective device (USGB) has a unique third identification number; that other subordinate protection devices have a unique fourth, fifth, etc. identification number. Protective switching system according to one of the preceding patent claims, characterized in that the external interruption unit (UEE) is a circuit breaker, circuit breaker, fault current circuit breaker or fire protection switch which is mechanically or electrically coupled to the higher-level protective device (OSG). Protective switching system according to one of the preceding claims, characterized in that the subordinate protective device (USGA) is arranged in or on an electrical consumer (LOADA) of the low-voltage circuit, is designed as an adapter plug for the low-voltage circuit or is arranged in a socket strip for a low-voltage circuit. Protective switching system according to one of the preceding patent claims, characterized in that the voltage difference value is greater than 13 volts, in particular greater than 20 volts. Protective switching system according to one of the preceding claims, characterized in that when the interrupt signal is received by the higher-level protective device (OSG), this initiates a delayed interrupt as a function of the level of the current (Iup) in the low-voltage circuit, such that at high currents a prompt interrupt occurs and at low currents a delayed interruption occurs. Protective switching system according to one of the preceding patent claims, characterized in that the comparison of the higher-level current change value with the received lower-level current change value takes place in a time window with a first period of time. Protective switching system according to one of the preceding patent claims, characterized in that when the subordinate protective device (USGA, USGB) is put into operation, a repeated current change in the low-voltage circuit is initiated. Protective switching system according to one of the preceding patent claims, characterized in that each or part of the transmissions contain a time stamp, in particular with the current time or additionally with the date. Protective switching system according to one of the preceding patent claims, characterized in that there is no interruption if the current level is less than a current threshold value, that the current threshold value is in particular less than 0.5 amperes. High-level protective device (OSG) for a low-voltage circuit, comprising: - a unique identification number, - a voltage sensor (SU1), to determine the voltage level (Vup) of the low-voltage circuit, - a current sensor (SI1) to determine the current level (Iup) of the low-voltage circuit, - a communication unit (COM1), for wireless communication, - a control unit (SE1) connected to the voltage sensor (SU1), the current sensor (SI1) and the communication unit (COM1), which is designed in such a way that the: - the overriding voltage level (Vup) and the overriding current level (Iup) are determined, - the determined overriding voltage level (Vup) together with the unique identification number is transmitted wirelessly by the communication unit (COM1), - a higher-level current change value, which is the difference between two chronologically consecutive higher-level current levels (Iup), is determined and compared with a lower-level current change value of a lower-level protection device received by the communication unit (COM1); if there is a match, the unique identification number of the lower-level protection device is saved in a positive list and a signal with the first identification number is sent to this sub-protection device, - that upon receipt of an interrupt signal, an interrupt of the low-voltage circuit is initiated only if the interrupt signal comes from a subordinate protection device with an identification number included in the whitelist. Higher-level protective device (OSG) according to Claim 11 , characterized in that an interruption unit is provided for interrupting the low-voltage circuit, which is connected to the control unit (SE1). Method of protecting a low-voltage circuit with a superordinate Protective device (OSG) and at least one subordinate protective device (USGA), for which: - a subordinate voltage level (Vdown2) and a subordinate current level (Idown2) are determined, - a subordinate current change value, which is the difference between two consecutively determined current levels (Idown2). , is determined, - the subordinate current level (Idown2) and the current change value are transmitted wirelessly together with an identification number of the subordinate protection device (USGA); - a higher-level voltage level (Vup) and a higher-level current level (Iup) is determined, - the higher-level voltage level (Vup) determined is transmitted wirelessly together with an identification number of the higher-level protective device (OSG), - the higher-level current level and a higher-level current change value that indicates the difference between two successive current levels is determined, - the received lower-level current change value is compared with the higher-level current change value, if they match, the lower-level identification number is saved in a positive list and a signal with the higher-level identification number is sent to the lower-level protection device (USGA), - that the subordinate protection device (USGA) on the received signal stores the superordinate protection device (OSG) with the superordinate identification number as its superordinate protection device and the determined subordinate voltage level (Vdown2) with the em compares the received voltage level (Vup) of its higher-level protective device (OSG) and, if a voltage difference value is exceeded, wirelessly transmits an interrupt signal with the subordinate identification number, - that the higher-level protective device (OSG) upon receipt of an interrupt signal only initiates an interrupt of the low-voltage circuit if the interrupt signal from a USGA with a whitelisted identification number. procedure after Claim 13 , characterized in that each subordinate protective device has its own unique identification number.

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