CN112614749A

CN112614749A - Low-voltage circuit breaker

Info

Publication number: CN112614749A
Application number: CN202011194842.7A
Authority: CN
Inventors: M.阿德尔霍克
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2014-09-18
Filing date: 2015-09-17
Publication date: 2021-04-06
Also published as: CN105448617A; DE102015217108A1

Abstract

In order to interrupt at least one electric circuit, the low-voltage circuit breaker has a triggering input, so that the at least one electric circuit is interrupted. The triggering input is connected to a disturbance arc detection unit which detects a disturbance arc in the event of its occurrence in the at least one electrical circuit and outputs a triggering signal to its output which leads to the triggering input of the low-voltage circuit breaker, so that the low-voltage circuit breaker can interrupt the at least one electrical circuit.

Description

Low-voltage circuit breaker

The application is a divisional application of patent applications with the application date of 2015, 9, 17 and the application number of Chinese patent application 201510594215.5 and the name of the invention of a low-voltage circuit breaker.

Technical Field

The present invention relates to a low-voltage circuit breaker.

Background

A circuit breaker is a special switch designed for switching high currents. The circuit breaker can switch not only the operating current and the low overload current but also the high overload current or the short-circuit current at the time of a fault, and also keep the fault current for a predetermined time and safely turn off. There are circuit breakers with different pole numbers, such as single pole, double pole, triple pole or quadruple pole.

From the viewpoint of being used as a simple switching element, the circuit breaker is used as a protection element at the time of a fault such as a short circuit, an overcurrent, or a ground. In this case, a switch refers to a low-voltage switch or a low-voltage circuit breaker, which is usually designed for operating voltages of up to 1000 volts and up to 2000 volts. For example for an alternating voltage of up to 1000 volts or a direct voltage of 1500 volts. Circuit breakers are typically used for currents from 100 amps up to 10000 amps. Special circuit breakers are used for currents starting from 63 amps or from 125 amps.

Circuit breakers, such as compact circuit breakers or molded case circuit breakers, open circuit breakers or air circuit breakers, are used in different distribution levels of an electrical distribution network, such as a main distribution network, a sub-distribution network, etc.

Disclosure of Invention

The invention aims to solve the technical problem of improving a low-voltage circuit breaker.

This technical problem is solved by a circuit breaker having the features of the present invention.

According to the invention, the low-voltage circuit breaker is extended with a disturbance arc detection unit, so that the circuit is also triggered or switched off in the event of a disturbance arc in the circuit. The core of the invention is the integration of the disturbance arc detection unit into a system complex with a circuit breaker. The occurrence of serial and/or parallel interference arcs can thus be detected and combined with a compact circuit breaker interrupting the circuit. This has the advantage that the low-voltage circuit breaker is expanded with further functions.

In a building installation, arcing can occur due to insulation failure, damage, broken and/or loose contacts. These arcs can cause fires. These arcs are referred to herein as nuisance arcs. Alternatively also referred to as fault arcing. That is, the disturbance arc recognition unit refers to a unit that recognizes an arc caused by an insulation fault, damage, wire breakage, and/or loose contact. Such an arc can occur as a so-called series arc, i.e. in a series circuit. In addition, it can also occur as a so-called parallel arc, i.e. between two wires of the circuit.

In particular, arcs which occur in the normal operation of the circuit, for example as a result of switching processes, are not included in the term interference arcs. These arcs should not be detected by interfering with the arc identification unit.

Such a disturbing Arc Detection unit is known in english as an Arc Fault Detection Device (Arc Fault Detection Device), abbreviated AFDD, and in north american areas as an Arc Fault Circuit Interrupter (Arc Fault Circuit Interrupter), abbreviated AFCI. Furthermore, the interference arc or fault arc detection unit is also referred to as a fire protection switch.

Preferred configurations of the invention are given in the dependent claims.

In a preferred embodiment of the invention, the disturbance arc detection unit is embodied as a module that can be added to the low-voltage circuit breaker. This has the particular advantage that it is utilized to extend new functionality to existing circuit breakers.

In a preferred embodiment of the invention, the interference arc detection unit is embodied as a module that can be inserted into the housing of the low-voltage circuit breaker. This has the particular advantage that a disturbing arc module can be installed in the circuit breaker instead of another module and thus provide a new function.

In a preferred embodiment of the invention, the interference arc detection unit is integrated in the housing of the low-voltage circuit breaker. Namely, the circuit breaker includes a disturbance arc identification unit. The circuit breaker thus has other functions, which are advantageously adapted to market requirements.

In a preferred embodiment of the invention, the interference arc detection unit is coupled to the fault current detection unit. This has the particular advantage that a compact unit can be realized which collects both the fault current and the interference arc, wherein the functional blocks can be used together.

Drawings

Embodiments of the present invention are illustrated in the drawings and will be explained in detail below. Wherein:

figure 1 shows a schematic view of a low-voltage circuit breaker with a disturbing arc module;

fig. 2 shows a schematic diagram of a low-voltage circuit breaker with a disturbing arc and fault current module;

fig. 3 shows a low-voltage circuit breaker with an integrated disturbing arc module.

Detailed Description

Fig. 1 shows a low-voltage circuit breaker MCCB which is capable of interrupting one circuit or a plurality of circuits with electrical leads N, L1, L2, L3. The contact system K is used for interruption. The low-voltage circuit breaker has an activation input E. If a trigger signal is applied to this trigger input, the electrical lines N, L1, L2, L3 are interrupted by the contact system K, i.e. the circuit is opened. This is also known as triggering or switching off the circuit breaker. The trigger input E is connected to the output of an interfering arc detection unit AFD, which can output a trigger signal at the output. The disturbance arc detection unit AFD has one or more sensors, for example a first sensor I, a second sensor HF, and has a control unit MCU and a power supply PS. There may also be a third sensor U, not shown.

The first sensor I is used to determine the current of the circuit. The second sensor HF is used to determine the HF spectrum of the circuit. A third sensor U is used to determine the voltage of the circuit. In a multiphase current system, preferably at least 2 of the 3 sensors are used. The control device MCU is used to control the disturbing arc identification unit AFD. It is designed to be able to detect an interference arc of the circuit or of the electrical line. For example, a disturbing arc can be detected in the circuit, which is fed via the low-voltage circuit breaker MCCB and has the electrical lines N, L1, L2, L3. If such a disturbing arc is detected and detected in the circuit, the disturbing arc detection unit AFD outputs a corresponding signal or trigger signal at its output a, which is received by the low-voltage circuit breaker MCCB at its input E and subsequently interrupts the circuit by means of the contact system K. The interference arc detection unit can be designed as an interference arc module according to fig. 1, which is connected to the circuit breaker MCCB via electrical lines. Alternatively, it can also be provided that a disturbance arc detection unit can be added to the circuit breaker MCCB.

The arrangement shown in fig. 2 differs from that shown in fig. 1 in that the disturbance arc detection unit AFD comprises a fault current detection unit or fault current module RCD. For example a combination of fault current identification and disturbance arc identification. That is to say, both fault currents and interference arcs can be detected by means of the module RCD/AFD. When one of these is present, a corresponding signal/trigger signal is output to the low-voltage circuit breaker MCCB, which interrupts the circuit if the trigger signal is applied. In the example of fig. 2, a disturbing arc identification unit AFD or a disturbing arc and fault current identification unit RCD/AFD may be added to the circuit breaker MCCB.

The arrangement shown in fig. 3 differs from fig. 1 in that the disturbing arc detection unit AFD is integrated in the low-voltage circuit breaker MCCB. Alternatively, the integrated disturbing arc identification unit can be disassembled, so that it can optionally be embedded in the circuit breaker MCCB as required. In a further variant, the disturbing arc identification unit can also be fixedly mounted in the circuit breaker MCCB.

The present invention is described in detail again below. Additional modules for different functions have been provided in part for circuit breakers. According to the invention, it is proposed to introduce a disturbance arc detection unit into a system combination with a low-voltage circuit breaker. This allows the central detection of series and/or parallel interference arcs. Optionally, other disturbance arc identification units can be combined to detect and identify disturbance arcs and thus to shut down the circuit to protect the power grid. This can be implemented, for example, in different main and/or sub-distribution networks. The interference arc detection unit can be arranged in the vicinity of the low-voltage circuit breaker, in the installation or integrated in the installation, or arranged remote from the low-voltage circuit breaker. In addition, the disturbance arc identification unit or the fault arc protection module, which is located on the main feed side or in the center or in a superordinate arrangement, can have a selectivity with respect to the fault arc protection module in the subsequently arranged partial distribution network. Selectivity refers to identifying or triggering a protection unit in close proximity to a fault. That is to say that as close as possible to the fault, i.e. the identified fault arc, a fault should be identified by a protection unit, i.e. a disturbance arc identification unit, there and the circuit interrupted there by means of a corresponding low-voltage circuit breaker. In this way, a centrally or superordinate fault arc protection module should not be triggered in the event of an interference arc in the sub-distribution network. This selective protection may be referred to as basic protection and additional protection.

In addition, the disturbance arc identification module can be integrated and integrated into a system union, for example by means of a bus connection. In the system integration, for example, data of the low-voltage circuit breaker and data of the interfering arc detection unit can be transmitted or transmitted to the monitor. In this case, the disturbance arc detection unit and/or the low-voltage circuit breaker are connected to a monitor, for example to a central computer. Information about the trigger may be displayed or notified. In addition, operating parameters may be displayed. Remote triggering is also possible, for example.

The disturbing arc identifying unit may:

a) the functional module is constructed into an independent module type;

b) as a functional module, into other units, for example into a fault current detection unit;

c) as a functional module directly integrated into a low-voltage circuit breaker;

d) as an extension module for a low-voltage circuit breaker, is realized in the form of a plug-in module.

In the system combination, the display can be carried out by means of light-emitting diodes, a display, control and notification lines, before or after the detection of the disturbing arc. Additionally, measurement and diagnostic process data may be displayed. The connection of the low-voltage circuit breaker, the disturbing arc module and/or the monitor can take place via, for example, the conductors of the triggering and remote triggering lines, the notification inputs or outputs.

In other embodiments of the invention, the interference arc module can be connected to an electronic tripping unit or an electronic tripping unit of the low-voltage circuit breaker.

Claims

1. A low-voltage circuit breaker for interrupting at least one polyphase circuit for currents starting from 63 amperes, designed in three or four poles, having a trigger input, by means of which the low-voltage circuit breaker can be triggered in order to interrupt at least one polyphase circuit for currents starting from 63 amperes, characterized in that the trigger input is connected to an interfering arc identification unit, which identifies an interfering arc in the event of an occurrence of this arc in at least one circuit and outputs a trigger signal to its output, which leads to the trigger input of the low-voltage circuit breaker in order to interrupt at least one circuit for currents starting from 63 amperes, the low-voltage circuit breaker having a trigger input, which is connected to a low-voltage circuit breaker, which is connected to the trigger input of the low-voltage circuit breaker,

the disturbance arc detection unit has a control unit, a first sensor for determining a current and a second sensor for determining a high-frequency spectrum of at least one circuit,

each phase of the multi-phase current system is provided with said sensor.

2. Low voltage circuit breaker as claimed in claim 1, characterized in that the disturbing arc identification unit is implemented as a module that can be added to the low voltage circuit breaker.

3. Low voltage circuit breaker as claimed in claim 1 or 2, characterized in that the disturbing arc recognition unit is embodied as a module which can be embedded in the housing of the low voltage circuit breaker.

4. Low voltage circuit breaker as claimed in any one of the preceding claims, characterized in that the disturbing arc identification unit is integrated into the housing of the low voltage circuit breaker.

5. Low voltage circuit breaker as claimed in any of the foregoing claims, characterized in that the disturbing arc identification unit is connected to the low voltage circuit breaker via a conductor.

6. Low voltage circuit breaker as claimed in any of the foregoing claims, characterized in that the disturbing arc identification unit is coupled with a fault current identification unit.

7. Low-voltage circuit breaker as claimed in claim 1, characterized in that the disturbing arc identification unit has a third sensor for determining the voltage of at least one circuit.

8. Low voltage circuit breaker as claimed in claim 1 or 7, characterized in that said first sensor determines the current and the high frequency spectrum of at least one circuit.

9. Low voltage circuit breaker as claimed in any of the foregoing claims, characterized in that the disturbing arc identification unit is selective with respect to other disturbing arc identification units.

10. Low voltage circuit breaker as claimed in any of the foregoing claims, characterized in that the disturbing arc identification unit has a power supply.

11. Low-voltage circuit breaker as claimed in claim 1, characterized in that said control unit has a microprocessor.

12. Low voltage circuit breaker as claimed in any one of the preceding claims, characterized in that the disturbing arc identification unit has a communication unit which can be connected to a communication branch for data interaction.

13. Low-voltage circuit breaker as claimed in claim 12, characterized in that the disturbing arc identification unit is constructed such that triggering data, diagnostic data, process data and/or control data can be transmitted and/or exchanged by means of the communication unit.

14. Low voltage circuit breaker as claimed in any of the foregoing claims, characterized in that the disturbing arc identification unit has a display unit.

15. Low-voltage circuit breaker as claimed in claim 14, characterized in that the display unit has a display and/or light-emitting diodes for displaying the operating state of the disturbing arc identification unit.