• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a residual current circuit breaker for a low-voltage circuit having at least two conductors, comprising: - a mechanism with contacts for interrupting and closing the circuit, - connected to the mechanism holding magnet release, for opening the contacts, - a summation current transformer, the one through the Conductor of the circuit formed primary circuit and a secondary winding, for determining a differential current of the electric circuit, - a trip circuit which connects the summation current transformer and the Hal temagnet trigger with each other, and which are designed such that activates when exceeding a residual current limit of the holding magnet release so that the electrical circuit is interrupted. The summation current transformer has a short-circuit winding.
    公开号:AT520576A2
    申请号:T50725/2018
    申请日:2018-08-24
    公开日:2019-05-15
    发明作者:
    申请人:Siemens Ag；
    IPC主号:
    专利说明:

    Summary
    The invention relates to a residual current circuit breaker for a low-voltage circuit with at least two conductors, comprising:
    - a mechanism with contacts to open and close the circuit,
    - a holding magnet release connected to the mechanics, for opening the contacts,
    a total current transformer, which has a primary circuit formed by the conductors of the circuit and a secondary winding, for determining a differential current of the electrical circuit,
    - A tripping circuit that connects the summation current transformer and the holding magnet release to one another, and which are designed such that when a differential current limit value is exceeded, the holding magnet release is activated so that the electrical circuit is interrupted. The summation current transformer has a short-circuit turn.
    Figure 2/19
    description
    Residual Current Device
    The invention relates to a residual current circuit breaker for a low-voltage circuit according to the preamble of claim 1.
    Residual current circuit breakers for electrical circuits, in particular for low-voltage circuits or systems, are generally known. Residual current circuit breakers are also referred to as residual current devices, or RCD for short.
    Low voltage means voltages up to 1000 volts AC and / or 1500 volts DC. Low voltage means in particular voltages which are greater than the low voltage, with values of 25 volts or 50 volts AC and 60 volts or 120 volts DC.
    Circuits, especially for low voltage, refer to circuits for currents up to 6300 amps, special currents up to 1600 amps, 1200 amps, 630 amps, 125 amps or 63 amps. The current values mentioned refer in particular to nominal or / and breaking currents, i.e. the maximum current that is normally conducted through the circuit or at which the electrical circuit is usually interrupted, for example by a protective device, such as a circuit breaker or a circuit breaker.
    Residual current circuit breakers are used in particular for nominal current ranges / currents up to 16, 25, 40, 63, 80 or 125 amps.
    Residual current circuit breakers determine the total current in an electrical circuit, which is normally zero, and interrupt when a residual current value is exceeded, i.e. a non-zero current sum that exceeds a certain / 19 (differential) current value or fault current value, the electrical circuit.
    Almost all previous residual current circuit breakers have a summation current transformer, the primary winding of which is formed by the conductors of the circuit and the secondary winding provides the sum of current which is used directly or indirectly to interrupt the electrical circuit.
    For this purpose, two or more conductors, mostly forward and return conductors or outer and neutral conductors in a single-phase alternating current network, all three outer conductors or all three outer conductors and the neutral conductor in a three-phase alternating current network are guided through a current transformer, which usually has an annular core made of ferromagnetic material , Only the differential current is converted, i.e. a current deviating from the outgoing and return current from the conductors. The total current in an electrical circuit is usually zero. In this way, fault currents can be recognized.
    If, for example, a current flows to earth on the energy sink side or consumer side, this is referred to as a fault current. An error occurs, for example, when there is an electrical connection from a phase conductor of the electrical circuit to earth. For example, when a person touches the phase conductor. Then part of the electrical current does not flow back as usual via the neutral or neutral conductor, but via the person and the earth. This fault current can now be detected with the aid of the total current transformer, since the sum total of the inflowing and returning current is not equal to zero. An interruption of the circuit, e.g., by means of a relay or a holding magnet release, for example with connected mechanics, causes at least one, part or all of the lines. Residual current circuit breakers for detecting alternating residual currents are generally known from the document DE 44 32 643 A1.
    / 19th
    A residual current circuit breaker essentially consists of the
    Functional groups summation current transformers, trip ice, holding magnet releases, mechanics and contacts.
    The main function of residual current circuit breakers is to protect people from electrical currents (electric shock) and to protect systems, machines or buildings from fire due to electrical insulation faults.
    If the residual current circuit breaker or its total current transformer is designed so that the secondary energy is sufficient to actuate a tripping unit or an interruption unit or a release, then such residual current circuit breakers are called independent of the mains voltage, otherwise dependent on the mains voltage.
    Residual current circuit breakers are available in different types, which are denoted by letters or letter combinations, such as AC, A, F, G, K, S, B, B +. Each type captures a certain type of fault current. Residual current circuit breakers are currently known as 2-pole for phase and neutral conductors (L + N), 3-pole for three phase conductors (L1, L2, L3) and 4-pole for three phase conductors and neutral conductors (L1, L2, L3, N).
    For example, type AC only detect purely sinusoidal fault currents. Type A detects both purely sinusoidal AC currents and pulsating DC residual currents. Type F are mixed frequency sensitive residual current protective devices. They detect all types of residual current, such as type A, and are also suitable for detecting residual currents that consist of a frequency mix of frequencies up to 1 kHz. Type K contains the characteristics of type A, but its switch-off behavior is delayed for a short time. Type S are selective residual current circuit breakers that can be staggered in the rated residual current as well as in the tripping time.
    There are also residual current circuit breakers for various residual current limits or residual currents. A value of 30 mA is usual for personal / 19 personal protection and a value of 300 mA for fire protection. For other or special applications, 100 mA, 500 mA, 1 ampere or other values are common.
    If a supplier of residual current circuit breakers wants to offer a wide range of residual current circuit breaker types and residual currents, a large number of residual current circuit breakers is required. Often, however, the number of pieces requested after certain fault currents is very small. The effort to provide a corresponding residual current circuit breaker type for a special residual current is often not in proportion to the effort. As a rule, the number of turns of the secondary winding must be changed for a different fault current, which leads to increased winding effort. In particular, the number of turns must be increased, which is often not possible or leads to space problems. Own types for certain fault currents are often not profitable due to the small number of pieces. As an alternative, so-called burden resistors can be provided in the secondary circuit or tripping circuit, which, however, are often space-intensive, so that this solution is often not practical, especially since it also leads to increased effort
    The object of the present invention is to improve a residual current circuit breaker of the type mentioned in the introduction, in particular for a residual current circuit breaker type, to enable a larger number of residual currents in a simple manner.
    This object is achieved by a residual current circuit breaker with the features of patent claim 1.
    According to the invention, a residual current circuit breaker is provided for a low-voltage circuit with at least two conductors, comprising:
    - a mechanism with contacts to open and close the circuit, / 19
    - a holding magnet release connected to the mechanics, for opening the contacts,
    a total current transformer, which has a primary circuit formed by the conductors of the circuit and a secondary winding, for determining a differential current of the electrical circuit,
    - A tripping circuit that connects the summation current transformer and the holding magnet release to one another, and which are designed such that when a differential current limit value is exceeded, the holding magnet release is activated so that the electrical circuit is interrupted.
    According to the invention, the summation current transformer has a short-circuit turn.
    Part of the fault current flows in this short-circuit turn (or short-circuited turn), which is “too much available for the holding magnet. Is the residual current circuit breaker e.g. designed for 30 mA (Idn = 30mA), however, if the residual current circuit breaker should only switch off when residual currents of 300 mA are reached, part of the residual current can be extracted from the secondary winding by means of a correspondingly dimensioned simple short-circuit winding; 30mA = 270mA) (where hysteresis losses are neglected for simplification).
    By means of a simple short-circuit turn on the summation current transformer, another fault current can thus advantageously be provided without changing the rest of the fault current circuit breaker.
    Advantageous embodiments of the invention are specified in the subclaims.
    In an advantageous embodiment of the invention, the short-circuit turn has several turns.
    This has the particular advantage that a larger area is available for setting the changed fault current.
    / 19th
    In an advantageous embodiment of the invention, the
    Summation current transformer a closed core with an opening on it
    - through which the conductors are led,
    - through which the turns of the secondary winding are passed,
    - through which the short-circuit turn is led.
    This has the particular advantage that a particularly compact design is made possible and that there is also a closed field of the core.
    In an advantageous embodiment of the invention, the summation current transformer has a core made of ferromagnetic material.
    This has the particular advantage that a particularly efficient summation current transformer is made possible which takes advantage of the permeability of such a material.
    In an advantageous embodiment of the invention, the short-circuit turn consists of an electrically conductive wire with a certain resistance.
    According to the invention, it was found that the short-circuit winding can be defined by its resistance. A specific resistance can advantageously be used to set a specific fault current or a specific fault current change.
    In an advantageous embodiment of the invention, the specific resistance of the short-circuit winding with a predetermined conductivity and a predetermined cross-section of the wire is defined by a specific length of the short-circuit winding. According to the invention, it was found that the short-circuit winding can be defined or adjusted particularly advantageously by the length given the conductor material or the specific resistance of the material and the cross section. This has the further particular advantage that a particularly simple setting and implementation of the short-circuit turn is possible.
    / 19th
    In an advantageous embodiment of the invention, a
    Test circuit provided with a first resistor and a test button to test the functionality.
    This has the particular advantage that there is a functional test of the modified fault current value.
    According to the invention, a short-circuit winding for a residual current circuit breaker, in particular for a summation current transformer, is also claimed.
    All configurations, both in a dependent form with reference to patent claim 1 and also with reference only to individual features or combinations of features of patent claims, bring about an improvement in a residual current circuit breaker for simple change in the residual current value.
    The described properties, features and advantages of this invention as well as the manner in which they are achieved will become clearer and more clearly understandable in connection with the following description of the exemplary embodiments which are explained in more detail in connection with the drawing.
    The drawing shows:
    FIG. 1 shows a first illustration of a residual current circuit breaker,
    FIG. 2 shows a second illustration of a residual current circuit breaker,
    Figure 3 is an equivalent circuit diagram of a circuit.
    FIG. 1 shows a basic illustration of a 4-pole residual current circuit breaker FI, comprising:
    - Several input connections 1, 3, 5, NE, for an energy source-side connection of the residual current circuit breaker to / 19 an energy source, for example a low-voltage circuit or a low-voltage network;
    - Several output connections 2, 4, 6, NA for an energy sink-side connection of the residual current circuit breaker to an energy sink, for example a consumer;
    - Several conductors L1, L2, L3, N of a low-voltage circuit to be protected, for example a three-phase AC circuit or network, a first conductor L1 being connected between the first input connection 1 and the first output connection 2, and also a second conductor L2 between the second input connection 3 and the second Output connection 4, ie a third conductor L3 is connected between third input connection 5 and third output connection 6, a fourth conductor N, for example Neutral conductor, is connected between the fourth input connection NE and the fourth output connection NA;
    - e.g. the first to third conductors L1, L2, L3 phase conductors and the fourth conductor N are a neutral conductor or neutral conductor of the three-phase AC circuit, for example;
    - several, e.g. first to fourth contacts K1, K2, K3, KN with which the first to fourth conductors L1, L2, L3, N can be opened or closed electrically, a contact being assigned to a conductor;
    - A mechanism M connected to the contacts K1, K2, K3, KN, for opening and closing the contacts K1, K2, K3, KN;
    - A holding magnet release A connected to the mechanism M, which essentially causes the contacts K1, K2, K3, KN to open;
    - A summation current transformer W1, the primary side of which is formed by the conductors L1, L2, L3, N, the conductors being passed through the summation current transformer W1, in the example the summation current transformer is designed as a closed core with an opening, for example as a ring core, e.g. made of ferromagnetic material, and which has a secondary winding SW, which has, for example, a plurality of turns n;
    a first connection V1 between the first connection of the secondary winding SWA1 and the first connection AA1 of the holding magnet release A;
    / 19th
    - A second connection V2 between the second connection of the
    Secondary winding SWA2 and second connection AA2 of the holding magnet release A.
    In one embodiment, the total current transformer can have a test winding PW. For example, analogous to the secondary winding SW.
    The secondary winding SW is connected to the holding magnet release A, so that a fault current induced in the secondary winding SW, which for example exceeds a differential current limit value or fault current value, triggers the holding magnet release A, for example in which the holding magnet is energized, for example as a relay so that a trip, ie an interruption of at least one, a part or all of the contacts is effected, so that the electrical circuit is interrupted. The interruption can be supported by a mechanism M, as shown.
    The tripping circuit, in particular the connection of the secondary winding / holding magnet release, can have further elements, such as a memory circuit.
    In the example according to FIG. 1, a test circuit having a series connection of a key T and a resistor R1 is shown. The test circuit is connected before the summation current transformer with one conductor, fourth conductor N in the example, and after the summation current transformer with another conductor, third conductor L3 in the example; the test circuit is guided past the total current transformer. A functional test of the total current transformer or residual current circuit breaker FI can be carried out with the test circuit, in which an artificial fault current is generated by pressing the T key (current sum of the conductors through the total current transformer is not equal to zero).
    / 19th
    Figure 2 shows an arrangement according to Figure 1, with the difference that the summation current transformer according to the invention
    Short-circuit winding KW has.
    The short-circuit turn can be designed as a short-circuited turn, but it can also comprise several turns, so that a wire length has several turns, the start of the wire being connected to the end of the wire.
    Several parallel short-circuit windings can also be provided.
    The invention will be explained in more detail below.
    Part of the fault current flows in the short-circuit turn, which is not available for the holding magnet or is "too much".
    Is e.g. Residual current circuit breaker or the summation current transformer and holding magnet release, for example a tape core in particular, designed for 30 mA fault current (Idn = 30mA), a trip can only be dimensioned with a suitably dimensioned short-circuit winding at a higher fault current.
    Should the residual current circuit breaker e.g. trigger at 300 mA, 270 mA must be absorbed by the short-circuit winding (300mA-30mA = 270mA). To simplify matters, hysteresis losses etc. are not taken into account or neglected.
    According to the invention, the required resistance is set by the conductor material, in particular the specific conductivity, the cross section and the length.
    The short-circuit turn can be calculated as follows. The circuit of the summation current transformer and the holding magnet / holding magnet release is as follows, in particular in the case of AC voltage types.
    FIG. 3 shows an equivalent circuit diagram of a circuit of the trip circuit.
    / 19th
    On the left-hand side LS of FIG. 3, which represents the side of the secondary winding SW of the summation current transformer, there is a first series connection of a voltage source Ui; an inductance Lp, the inductance of the secondary winding SW; and a resistance Rcu, the line resistance. This first series connection is connected to a second series connection, which is shown on the right-hand side RS of FIG. 3.
    The second series circuit has a resistance Rs and an inductance Ls of the holding magnet release.
    The ratios are as follows.
    Nplres - N plp + N Ks! KS + N S Him
    Iks -
    NI 1N plres
    Nplp n s! Hm N KS where:
    N P - primary number of turns
    N KS - number of short-circuit turns
    N s - number of secondary turns
    Ires = resulting current = primary current of the base trip circuit (e.g. 22.5mA)
    I P - primary current of the derived trip circuit (e.g. 225mA)
    I KS - current in the short circuit loop
    Him - holding magnet current
    If the phase shift caused by the transducers and the holding magnet inductors is neglected for the sake of simplicity (precise observation possible by simulation), the following expression is produced:
    T _ N p I p N S I HM N p I res I KS - N N KS / 19
    The induced voltage in the short circuit loop is calculated as follows:
    u ks I res
    Ap e * ω * -— * μ * N p * N l Fe
    KS where:
    Uks = induced short-circuit loop voltage ω = angular frequency of the fault current
    A Fe = magn. Effective cross-sectional area of the band core l Fe = length of iron path of the band core μ = permeability
    The ohmic resistance that the short circuit loop should have is calculated as follows:
    => R _ U ks
    Ks = f I KS l
    => r ks = pa where:
    R KS = ohmic resistance of the KS loop ρ = spec. Resistance l = length of the short circuit loop
    A = electr. conductive cross sectional area of the KS loop
    The parameter A can e.g. be determined and thus the length is calculated as follows:
    AU ks => l = Ρ Iks
    A Ires * ω * * μ * Ν ρ * N KS => l = ------------ ρ I KS / 19
    From a 30mA residual current circuit breaker, a 300mA fault example
    Ler current circuit breaker are generated. Primary current of the basic trip circuit: 22.5 mA, derived current of the trip circuit: 225 mA. The short-circuit turn or loop should be made of copper, electrical conductivity or the resistance ρ for copper, specific Wimit A = 0.4mm 2 . The result is:
    Iks N p! P N sIhM N p I res N KS * 225mA - 5 * 4.3mA - 2 * 22.5mA
    Iks = --------------- 1 --------------- = 384mA
    A Ires * ω * * μ * Np * N KS => l = ------------- ρI
    OOP Λ 0-1 / 1 -1 27.1mm 2 _ _ c Vs _.
    _ (0.4 mm) 2 * π * 22,5mA 314S 1 * 379mm * 0, 75 Am '2' 1 =>'= m 4.0,17-
    => l = 14.6cm
    The short circuit turn has a length of 14.6 cm.
    Attaching a short-circuit turn is much cheaper than installing load resistors on the holding magnet, which would be in the tenths of an ohm range. Precise load resistors are often not available in the required value or are very expensive (current measurement shunt resistors); or have a large design.
    With the invention, any, in particular higher, fault currents can be introduced in many product series, in particular for AC types.
    / 19th
    Technically speaking, the short-circuit turn even solves three
    problems:
    The summation current transformer is not brought to saturation by the increased secondary current, i.e. the operating point remains 5 in the linear range.
    The holding magnet release can still be operated in the usual or specified (apparent power) range despite the higher nominal residual current.
    The holding magnet pins remain free due to the lack of burden resistors 10, e.g. for a protective diode.
    Although the invention has been illustrated and described in more detail by the exemplary embodiment, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.
    / 19th
    权利要求:
    Claims (8)
    [1]
    claims
    1. A residual current circuit breaker (FI) for a low-voltage circuit with at least two conductors, comprising:
    - a mechanism (M) with contacts for interrupting and closing the circuit,
    - a holding magnet release (A) connected to the mechanism (M), for opening the contacts (K1, K2, K3, KN),
    a total current transformer (W1), which has a primary circuit formed by the conductors of the circuit and a secondary winding (SW), for determining a residual current of the electrical circuit,
    a tripping circuit which connects the summation current transformer (W1) and the holding magnet release (A) to one another, and which are designed such that when a residual current limit value is exceeded, the holding magnet release (A) is activated so that the electrical circuit is interrupted, characterized in that the summation current transformer (W1) has a short-circuit turn (KW).
    [2]
    2. Residual current circuit breaker (FI) according to claim 1, characterized in that the short-circuit turn (KW) is formed by several turns.
    [3]
    3. Residual current circuit breaker (FI) according to claim 1 or
    2, characterized in that the summation current transformer (W1) has a closed core with an opening,
    - through which the conductors are led,
    - through which the turns of the secondary winding (SW) are guided,
    - through which the short-circuit turn (KW) is led.
    [4]
    4. residual current circuit breaker (FI) according to claim 1, 2 or 3,
    16/19 characterized in that the total current transformer (W1) has a core made of ferromagnetic material.
    [5]
    5. Residual current circuit breaker (FI) according to one of the preceding claims, characterized in that the short-circuit winding (KW) consists of an electrically conductive wire with a certain resistance.
    [6]
    6. Residual current circuit breaker (FI) according to claim 5, s characterized in that the specific resistance of the short-circuit winding (KW) is defined by a specific length of the short-circuit winding (KW) for a given conductivity and cross-section of the wire.
    [7]
    7. Residual current circuit breaker (FI) according to one of the preceding claims, characterized in that a test circuit with a first resistor (R1) and a test button (T) is provided for testing the functionality.
    [8]
    8. Short-circuit winding (KW) for a residual current circuit breaker, in particular for a summation current transformer, according to one of the preceding claims.
    17/19
    1.2
    类似技术:
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    DE567079C|1933-01-03|Device for preventing the persistence of fault currents, for example in the event of earth faults in electrical systems
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    同族专利:
    公开号 | 公开日
    DE102017217411A1|2019-04-04|
    AT520576A3|2020-02-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE2336260B1|1973-07-17|1974-07-11|Baco Const Elect|Toroidal core converter for residual current circuit breaker high sensitivity|
    DE2542852B1|1975-09-25|1976-09-16|Siemens Ag|Faulty current protective circuit breaker - has summation transformer with additional short circuit winding with specified resistance|
    DE2642392A1|1976-09-21|1978-03-23|Maier & Cie C|Circuit breaker tripping system - has transformer whose secondary feeds magnetic trip winding and whose tertiary is coupled to impedance|
    JPS55127826A|1979-03-26|1980-10-03|Fuji Electric Co Ltd|Leakage breaker|
    DE4432643B4|1994-09-14|2005-12-01|Aeg Niederspannungstechnik Gmbh & Co Kg|Contact arrangement for a residual current circuit breaker|DE102019212661A1|2019-08-23|2021-02-25|Siemens Aktiengesellschaft|Electronic circuit breaker and method|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102017217411.0A|DE102017217411A1|2017-09-29|2017-09-29|Residual Current Device|
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