Circuit breaker device and method

Abstract

The invention relates to a circuit breaker device (SG) for protecting an electrical low-voltage AC circuit, having: - a mechanical separating contact unit (MK), which can be switched between a closed state of the contacts for a current flow through the conductors of the low-voltage AC circuit and an open state of the contacts in order to prevent a current flow by galvanically isolating the conductors of the low-voltage AC circuit, wherein - the mechanical separating contact unit (MK) is connected in series with an electronic interruption unit (EU), - the electronic interruption unit ( EU) can be switched, by means of semiconductor-based switching elements, into a high-ohmic state of the switching elements in order to prevent a current flow through at least one conductor or into a low-ohmic state of the switching elements for a current flow through the low-voltage AC circuit, - the level of the current of the low-voltage AC circuit is determined and if current and / or current / time limit values are exceeded, a process of preventing a current flow through the low-voltage AC circuit is initiated, and - the electronic interruption unit (EU) can be switched into a high-ohmic or low-ohmic state using a ripple control signal.

Description

[0001] 202422267

[0002] 1

[0003] Description

[0004] Protective switching device and procedure

[0005] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0006] The invention relates to the technical field of a protective switching device for a low-voltage alternating current circuit with an electronic interruption unit and a method for a protective switching device for a low-voltage alternating current circuit with an electronic interruption unit.

[0007] Low voltage refers to voltages up to 1000 volts AC or up to 1500 volts DC. In particular, low voltage refers to voltages higher than extra-low voltage, defined as 50 volts AC or 120 volts DC.

[0008] Low-voltage AC circuits, networks, or installations refer to circuits with rated currents of up to 125 amperes, or more specifically, up to 63 amperes. Low-voltage AC circuits specifically include circuits with rated currents of up to 50 amperes, 40 amperes, 32 amperes, 25 amperes, 16 amperes, or 10 amperes. These current values ​​refer specifically to rated, rated, and / or tripping currents, i.e., the maximum current that normally flows through the circuit or at which the electrical circuit is typically interrupted, for example, by a protective device such as a circuit breaker, miniature circuit breaker, or miniature circuit breaker. The rated currents can be further staggered, from 0.5 A through 1 A, 2 A, 3 A, 4 A, 5 A, 6 A, 7 A, 8 A, 9 A, 10 A, etc. up to 16 A.

[0009] Miniature circuit breakers (MCBs) are long-established overcurrent protection devices used in electrical installations in low-voltage AC circuits. They protect conductors from damage caused by overheating due to excessive current and / or short circuits. A MCB can automatically disconnect the circuit in case of overload and / or short circuit. A MCB is a non-resetting safety device.

[0010] 2

[0011] Unlike miniature circuit breakers (MCBs), power circuit breakers are designed for currents greater than 125 A, and sometimes even as low as 63 A. MCBs are therefore simpler and more delicate in design. MCBs typically have a mounting option for installation on a DIN rail (also known as a top-mounted rail or TH35 rail).

[0012] Miniature circuit breakers (MCBs) are electromechanical devices. Within a housing, they contain a mechanical switching contact or shunt trip for interrupting (tripping) the electrical current. Typically, a bimetallic element is used for tripping (interruption) in the event of a sustained overcurrent (overcurrent protection) or thermal overload (overload protection). An electromagnetic trip with a coil is used for momentary tripping when an overcurrent limit is exceeded or in the event of a short circuit (short-circuit protection). One or more arc-quenching chambers or devices are provided. Furthermore, they include connection elements for conductors of the electrical circuit to be protected.

[0013] Protective switching devices with an electronic interruption unit are relatively new developments. These devices feature a semiconductor-based electronic interruption unit. This means that the electrical current flow of the low-voltage AC circuit is routed through semiconductor components or semiconductor switches that can interrupt the electrical current flow or be switched to conductivity. Protective switching devices with an electronic interruption unit also frequently feature a mechanical disconnect contact unit, particularly with isolating properties according to relevant standards for low-voltage AC circuits. The contacts of the mechanical disconnect contact unit are connected in series with the electronic interruption unit, meaning that the current of the low-voltage AC circuit to be protected is routed through both the mechanical disconnect contact unit and the electronic interruption unit.

[0014] The invention relates in particular to low-voltage alternating current circuits with an alternating voltage, usually a time-dependent sinusoidal alternating voltage with frequency f. The time dependence of the instantaneous voltage value u(t) of the alternating voltage is given by the equation:

[0015] u(t) = II * sin (2TT * f * t)202422267

[0016] 3

[0017] described. Whereby:

[0018] u(t) = instantaneous voltage value at time t

[0019] U = Amplitude of the voltage

[0020] A harmonic alternating voltage can be represented by the rotation of a phasor whose length corresponds to the amplitude (II) of the voltage. The instantaneous displacement is the projection of the phasor onto a coordinate system. One oscillation period corresponds to one full rotation of the phasor, and its full angle is 2TT (2π) or 360°. The angular frequency is the rate of change of the phase angle of this rotating phasor. The angular frequency of a harmonic oscillation is always 2TT times its frequency, i.e.,

[0021] w = 2TT*f = 2TT / T = angular frequency of the alternating voltage

[0022] (T = period of the oscillation)

[0023] The angular frequency (w) is often preferred over the frequency (f), since many formulas in oscillation theory can be represented more compactly using the angular frequency due to the occurrence of trigonometric functions whose period is by definition 2TT:

[0024] u(t) = U * sin(wt)

[0025] In the case of angular frequencies that are not constant over time, the term instantaneous angular frequency is also used.

[0026] In the case of a sinusoidal, especially time-constant, alternating voltage, the time-dependent value of the angular velocity w and the time t corresponds to the time-dependent angle cp(t), which is also called the phase angle cp(t).

[0027] This means the phase angle cp(t) periodically traverses the range O...2TT or 0°...360°. This means the phase angle periodically assumes a value between 0 and 2TT or 0° and 360° (cp = n*(0...2TT) or cp = n*(0°...360°), due to periodicity; simplified: (p = O...2TT or (p = 0°...360°).

[0028] The instantaneous voltage value u(t) therefore refers to the instantaneous value of the voltage at time t, i.e., in the case of a sinusoidal (periodic) alternating voltage, the value of the voltage at the phase angle cp (cp = 0...2TT or cp = 0°...360°, the respective202422267

[0029] 4

[0030] Period). In contrast to the instantaneous voltage or current value, there is the RMS value of the voltage or the RMS value of the current. In electrical engineering, the RMS value is understood to be the root mean square value of a time-varying physical quantity. The term is preferably applied to alternating quantities.

[0031] The effective value of a variable quantity is equal to the value of an equivalent quantity that would dissipate the same amount of electrical energy in a resistive load over a representative period of time. An equivalent statement applies to electrical power. The effective value depends on both the peak value and the waveform. In English, the effective value is denoted by RMS (abbreviation for Root Mean Square).

[0032] The object of the present invention is to improve a protective switching device of the type mentioned above, in particular to provide greater flexibility or a new feature for the protective switching device.

[0033] This problem is solved by a protective switching device having the features of claim 1, and by a method according to claim 12.

[0034] According to the invention, a protective switching device for the protection of a low-voltage alternating current electrical circuit is proposed, comprising:

[0035] - an enclosure with at least two mains-side connections and at least two load-side connections, for connecting at least two conductors of the low-voltage alternating current circuit,

[0036] - a mechanical isolating contact unit which can be switched by a closed state of the contacts to allow current flow in the conductors of the low-voltage alternating current circuit or by an open state of the contacts to prevent current flow by means of galvanic isolation of the conductors of the low-voltage alternating current circuit, - that the mechanical isolating contact unit is connected in series with an electronic interruption unit,

[0037] - that the electronic interruption unit can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow in at least one conductor or a low-resistance state of the switching elements to allow current flow in the low-voltage alternating current circuit,

[0038] - a current sensor unit, for determining the magnitude of the current

[0039] low-voltage alternating current circuit, 202422267

[0040] 5

[0041] - a control unit connected to the current sensor unit, the mechanical disconnect contact unit and the electronic interrupt unit, wherein, if current and / or current time limits are exceeded, a current flow in the low-voltage alternating current circuit is prevented,

[0042] - that the protective switching device includes a unit for receiving a ripple control signal,

[0043] - that the protective switching device is designed in such a way,

[0044] that the electronic interruption unit can be switched to a high-impedance or low-impedance state by means of a ripple control signal.

[0045] The unit for receiving the ripple control signal is specifically connected to the control unit.

[0046] This has the advantage that a protective switching device can be controlled by a ripple control signal, in particular the electronic interruption unit can be switched to a high-impedance or low-impedance state. This provides a solution that combines protection and (ripple) control functions in a single device, thus expanding the functionality of a protective switching device.

[0047] Further advantageous embodiments of the invention are specified in the dependent claims and in the exemplary embodiment.

[0048] In an advantageous embodiment of the invention, the mechanical disconnect contact unit is assigned to the load-side connection and the electronic interruption unit to the network-side connection. In particular, the mechanical disconnect contact unit can be operated by a mechanical handle to switch the contacts open or closed.

[0049] This has the particular advantage that a structure for a protective switching device is provided in which the functionality of the protective switching device is ensured even when the contacts of the mechanical isolating contact unit are open, so that the possibility of receiving a ripple control signal is always available.

[0050] In an advantageous embodiment of the invention, a first voltage sensor unit connected to the control unit is provided (as a unit for receiving the ripple control signal) to determine the voltage level of the low-voltage AC circuit. The ripple control signal is derived from the measurement of the voltage of the low-voltage AC circuit.

[0051] 6

[0052] This has the particular advantage that the ripple control signal modulated onto the low-voltage AC circuit can be derived from the measurement of the (mains) voltage. Furthermore, the voltage sensor unit can be used both for determining the voltage level and for determining or deriving the ripple control signal.

[0053] In an advantageous embodiment of the invention, the unit for receiving the ripple control signal has a filter, in particular a bandpass filter, for filtering out the ripple control signal from the low-voltage AC circuit, in particular from the voltage of the low-voltage AC circuit.

[0054] The first voltage sensor unit can therefore have such a filter.

[0055] This has the particular advantage of enabling better detection, better reception, and more reliable processing of the ripple control signal.

[0056] In an advantageous embodiment of the invention, a configuration unit is provided for the configurable controllability of the protective switching device by means of the ripple control signal.

[0057] This has the particular advantage that the use of the ripple control signal can be set or configured, thus providing increased flexibility of the protective switching device.

[0058] In an advantageous embodiment of the invention, the electronic interruption unit can only be switched to a low-impedance state by means of the ripple control signal if an enable condition is present. In particular, if the electronic interruption unit is in a high-impedance state caused by a protective function of the protective switching device, it cannot be switched to the low-impedance state by means of the ripple control signal (especially not within an initial period of time after becoming high-impedance).

[0059] The first duration can be in the range of 10 seconds or longer.

[0060] This has the particular advantage that the basic function of the protective switching device - to provide protection - is not affected by the ripple control signal and, for example, a defective protective switching device (no enable condition) cannot be forcibly switched on by the ripple control signal, i.e., supplying the low-voltage AC circuit with unprotected energy.

[0061] Furthermore, that, particularly in the case of a high-impedance state of the electronic interruption unit caused by a protective function of the protective switching device (for example, when / after exceeding current and / or current-time limits), this high-impedance state cannot be changed by the ripple control signal, i.e., the low-impedance state cannot be forcibly (immediately) switched back on. Thus, the protective device only 202422267

[0062] 7

[0063] After the error has been acknowledged or after the error is no longer present, it can be switched again with low resistance.

[0064] In an advantageous embodiment of the invention, the protection switch-side verification functions are

[0065] a) switch an electronic interrupting unit in a high-impedance state to a low-impedance state for a first period of time or (and)

[0066] b) switch an electronic interrupting unit that is in a low-impedance state to a high-impedance state for a second period of time,

[0067] not affected by the ripple control signal (i.e., the verification functions are performed independently of the (status of the) ripple control signal).

[0068] This has the particular advantage that the monitoring functions of the protective switching device are not affected by the ripple control signal, thus ensuring functional reliability, especially through monitoring functions (during operation) of the protective switching device.

[0069] The first time interval is, for example, a short period in the range of ps or ms up to one second, such as 100 ps ... 200 ps ... 300 ps ... 600 ps ... 700 ps ... 800 ps ... 1 ms ... 10 ms ... 20 ms ... 40 ms ... 50 ms ... 100 ms ... 200 ms ... 500 ms ... 1 s (any intermediate value is possible). The second time interval is, for example, a short period in the range of ps or ms up to one second, such as 100 ps ... 200 ps ... 300 ps ... 600 ps ... 700 ps ... 800 ps ... 1 ms ...

[0070] 10ms ... 20ms ... 40ms ... 50ms ... 100ms ... 200ms ... 500ms ... 1s (any intermediate value possible).

[0071] In an advantageous embodiment of the invention, the contacts of the mechanical isolating contact unit can be opened by means of the ripple control signal,

[0072] In particular, it is configurable whether the ripple control signal is used.

[0073] a) the electronic interruption unit can be switched to a high-impedance or low-impedance state or

[0074] b) the contacts of the mechanical disconnect contact unit are openable.

[0075] This has the particular advantage of providing further flexibility and functional expansion of the protective switching device.

[0076] In an advantageous embodiment of the invention, a display unit connected to the control unit is provided, which has visible indicators on the protective switching device for indicating the high-resistance or low-resistance state of the electronic interruption unit.

[0077] 8

[0078] This has the particular advantage of providing a visualization of the state of the electronic interruption unit.

[0079] In an advantageous embodiment of the invention, the protective switching device is designed such that, in the case of a high-impedance state of the electronic interruption unit initiated by the ripple control signal, this high-impedance state of the electronic interruption unit is established at the current zero crossing.

[0080] At current zero crossing means directly at or near the current zero crossing, i.e., for example, at an instantaneous current value that is less than a first current limit, for example, less than 5 amperes ... 1 ampere (any intermediate value is possible; the first current limit depends on the rated current of the low-voltage AC circuit or protective switching device, for example, 20% ... 15% ... 10% ... 5% ... 1% or less of the rated current).

[0081] This has the particular advantage of supporting virtually power-free switching, thus reducing the load on the electronic interrupt unit, especially its semiconductor-based switching elements.

[0082] In an advantageous embodiment of the invention, the (first) voltage sensor unit connected to the control unit determines instantaneous voltage values. The protective switching device is designed such that, if the electronic interrupt unit enters a low-impedance state initiated by the ripple control signal, this low-impedance state is restored at the voltage zero crossing. Alternatively or additionally, if the electronic interrupt unit enters a high-impedance state initiated by the ripple control signal, this high-impedance state is restored at the voltage zero crossing. This has the particular advantage of supporting further virtually power-free switching and thus reducing the load on the electronic interrupt unit, especially its semiconductor-based switching elements.

[0083] At the zero crossing of the voltage means directly at or near the zero crossing of the voltage, i.e., for example, at an instantaneous value of the voltage that is less than a first voltage limit, for example, less than 10 volts, 25 volts, or 50 volts (any intermediate or smaller value is possible).

[0084] According to the invention, a corresponding method for a protective switching device for a low-voltage alternating current circuit with electronic (semiconductor-based) switching elements is claimed, offering the same and further advantages. 202422267

[0085] 9

[0086] The method for a protective switching device for the protection of a low-voltage alternating current electrical circuit with at least two conductors, comprising:

[0087] - a mechanical isolating contact unit which can be switched by a closed state of the contacts to allow current flow in the conductors of the low-voltage alternating current circuit or by an open state of the contacts to prevent current flow by means of galvanic isolation of the conductors of the low-voltage alternating current circuit,

[0088] - that the mechanical disconnect contact unit is connected in series with an electronic interruption unit,

[0089] - that the electronic interruption unit can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow in at least one conductor or a low-resistance state of the switching elements to allow current flow in the low-voltage alternating current circuit,

[0090] - that the magnitude of the current in the low-voltage circuit is determined and, if current and / or current time limits are exceeded, i.e., if a current of a certain magnitude is present for a certain period of time, a current flow prevention measure is initiated in the low-voltage circuit,

[0091] - that the electronic interrupt unit can be switched to a high-impedance or low-impedance state by means of a ripple control signal (transmitted in the low-voltage alternating current circuit).

[0092] All embodiments, both in dependent form relating back to patent claim 1 or

[0093] 12, as well as referring back only to individual features or combinations of features of patent claims, in particular also a reference of the dependent arrangement claims to the independent method claim (and vice versa), effect an improvement of a protective switching device, in particular an improvement of the functionality and provide a new concept for a protective switching device.

[0094] The described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawing.

[0095] 10

[0096] The drawing shows:

[0097] Figure 1 shows a first representation of a protective switching device,

[0098] Figure 2 shows a second representation of a protective switching device,

[0099] Figure 3 shows a third representation of a protective switching device,

[0100] Figure 4 shows a representation of a functional grouping,

[0101] Figure 5 shows a representation of a first configuration,

[0102] Figure 6 shows a representation of a second configuration.

[0103] Figure 1 shows a representation of a protective switching device SG for the protection of a low-voltage alternating current electrical circuit with a housing GEH, comprising:

[0104] - a mains-side neutral conductor connection NG, a mains-side phase conductor connection LG, a load-side neutral conductor connection NL, a load-side phase conductor connection LL for conductors of the low-voltage alternating current circuit;

[0105] A power source is usually connected to the grid side.

[0106] A consumer is usually connected to the load side;

[0107] - a (two-pole) mechanical disconnect contact unit MK with load-side connection points APLL, APNL and network-side connection points APLG, APNG,

[0108] where a load-side connection point APNL is provided for the neutral conductor, a load-side connection point APLL for the phase conductor, a network-side connection point APNG for the neutral conductor, and a network-side connection point APLG for the phase conductor. The load-side connection points APNL and APLL are connected to the load-side neutral and phase conductor connections NL and LL, respectively, so that the opening of contacts KKN and KKL to prevent current flow or the closing of the contacts to allow current flow in the low-voltage AC circuit can be switched.

[0109] The mechanical disconnect contact unit can also be designed as a single-pole mechanical disconnect contact unit, i.e. with one contact, wherein the contact KKL is preferably arranged in the phase conductor L.

[0110] - an electronic interruption unit EU, in particular a single-pole unit, (which in the case of a single-pole design is in particular arranged in the phase conductor L,)

[0111] with a network-side connection point EUG, which is connected to the network-side phase conductor connection202422267

[0112] 11

[0113] LG is electrically connected, and

[0114] a load-side connection point EUL which is electrically connected to the network-side connection point APLG of the mechanical disconnect contact unit MK, wherein the electronic interruption unit has a high-resistance state of the switching elements to prevent current flow or a low-resistance state of the switching elements to allow current flow in the low-voltage alternating current circuit by means of semiconductor-based switching elements,

[0115] - a current sensor unit Sl, for determining the magnitude of the current of the low-voltage alternating current circuit, which is arranged in particular in the phase conductor L, - a control unit SE, which is connected to the current sensor unit Sl, the mechanical disconnect contact unit MK and the electronic interruption unit EU, wherein, in the event of current and / or current time limits being exceeded, a current flow in the low-voltage alternating current circuit is prevented.

[0116] According to the invention, the protective switching device SG is designed such that a unit (RE) for receiving a ripple control signal is provided on the protective switching device SG. The protective switching device is designed such that the electronic interruption unit EU can be switched to a high-impedance or low-impedance state by means of a received ripple control signal.

[0117] Furthermore, a first voltage sensor unit SUA connected to the control unit SE can be provided, which determines the voltage level, in particular instantaneous voltage levels, of the low-voltage AC circuit, especially at the mains-side terminals LG, NG, specifically between the mains-side neutral terminal NG and the mains-side phase terminal LG. Advantageously, the electronic interruption unit EU switches to the low-impedance state, in particular by the ripple control signal, when the instantaneous voltage level falls below a first voltage limit, which is in particular less than or equal to 50 volts (or 25 volts or 10 volts).

[0118] For example, if the electronic interrupt unit EU is to be switched to the low-impedance state (on) via the ripple control signal, the switch-on signal is only sent from the control unit SE to the electronic interrupt unit EU when the instantaneous voltage level falls below the first voltage threshold, which is typically less than or equal to 50 volts. This results in a time delay between the moment the ripple control signal is sent and the electronic interrupt unit EU being in the low-impedance state, for example, up to approximately 10 ms (at a 50 Hz mains frequency) (plus processing times). The same applies to [202422267].

[0119] 12

[0120] For the high-impedance switching of the electronic interrupt unit EU initiated by the ripple control signal. When the high-impedance switching of the electronic interrupt unit EU is initiated by the ripple control signal, the first current limit can be used as an alternative to the first voltage limit.

[0121] In general, the mechanical disconnect contact unit MK and the electronic interruption unit EU form a series circuit. This series circuit is connected to at least one mains-side connection and at least one load-side connection. Advantageously, the mechanical disconnect contact unit MK can be assigned to the load-side connection and the electronic interruption unit EU to the mains-side connection, as shown in Figure 1. The mechanical disconnect contact unit MK can be operated by a mechanical handle HH to switch the contacts open or closed, similar to a conventional line switch or miniature circuit breaker (MCB).

[0122] The control unit SE can include a microcontroller MP (microcontroller unit) (as shown in Figure 2).

[0123] Furthermore, a second voltage sensor unit SUB connected to the control unit SE may be provided, which determines the voltage level between the grid-side connection point EUG and the load-side connection point EUL of the electronic interruption unit EU.

[0124] A measuring impedance ZM can be connected between the mains-side connection points APLG and APNG of the mechanical isolating contact unit MK. The measuring impedance ZM can be, for example, an electrical resistor and / or capacitor. The measuring impedance can also be an inductor. In particular, the measuring impedance can be a series or parallel connection of a resistor and / or capacitor and / or inductor.

[0125] In the example shown in Figure 1, the electronic interruption unit EU is single-pole, located in the phase conductor. Here, the mains-side connection point APNG for the neutral conductor of the mechanical disconnect contact unit MK is connected to the mains-side neutral conductor connection NG of the housing GEH. In a single-pole version, this connection can be omitted, as can the neutral conductor contact KKN of the mechanical

[0126] T disconnect contact unit.202422267

[0127] 13

[0128] The protective switching device SG is advantageously designed such that the contacts of the mechanical isolating contact unit MK can be opened by the control unit SE, but not closed, as indicated by an arrow from the control unit SE to the mechanical isolating contact unit MK. This means, for example, that in one configuration the contacts of the mechanical isolating contact unit MK can be opened by means of the ripple control signal, but not closed.

[0129] The mechanical disconnect contact unit MK can be operated by a mechanical handle HH on the protective switching device SG to manually open or close the contacts KKL and KKN. The mechanical handle HH indicates (specifically through a mechanical connection between the contacts and the handle) the switching state (open or closed) of the contacts of the mechanical disconnect contact unit MK on the protective switching device.

[0130] The mechanical disconnect contact unit MK is advantageously designed such that (manual) closing of the contacts by the mechanical handle is only possible after an enable signal. This is also indicated by the arrow from the control unit SE to the mechanical disconnect contact unit MK. That is, the contacts KKL and KKN of the mechanical disconnect contact unit MK can only be closed by the handle HH when the enable signal (from the control unit) is present. Without the enable signal, the handle HH can be actuated, but the contacts cannot be closed ("continuous slip").

[0131] The protective switching device SG has a power supply NT, for example, a power supply unit. In particular, the power supply NT is provided for the control unit SE, as indicated by a connection between the power supply NT and the control unit SE in Figure 1. The power supply NT is (on the other hand) connected to the mains-side neutral conductor terminal NG and the mains-side phase conductor terminal LG. A fuse SS, in particular a cartridge fuse, and / or a switch can advantageously be provided in the connection to the mains-side neutral conductor terminal NG (and / or phase conductor terminal LG).

[0132] In the case of a purely single-pole protective switching device, the power supply is provided by an external power source / additional connections. 202422267

[0133] 14

[0134] High resistance refers to a state in which only a negligible current flows. Specifically, high resistance values ​​greater than 1 kilohm, preferably greater than 10 kilohms, 100 kilohms, 1 megahms, 10 megahms, 100 megahms, 1 gigahms, or higher.

[0135] Low resistance refers to a state in which the current value specified on the protective switching device could flow.

[0136] In particular, low resistance values ​​are meant to be less than 10 ohms, preferably less than 1 ohm, 100 milliohms, 10 milliohms, 1 milliohm or less.

[0137] The mechanical disconnect contact unit MK can, in one variant, interrupt a single pole. This means that only one conductor (of the two / multiple conductors), specifically the live conductor or phase conductor, is interrupted, i.e., it has a mechanical contact. The neutral conductor is then without contact, i.e., the neutral conductor is directly connected.

[0138] In a second variant of the mechanical disconnect contact unit MK, the neutral conductor also has mechanical contacts, as shown in Figure 1.

[0139] The term "mechanical disconnect contact unit MK" refers specifically to a (standard-compliant) disconnect function, implemented by the disconnect contact unit MK. The following points are included with the disconnect function:

[0140] -Minimum air gap according to standard (minimum distance between contacts),

[0141] - (Mechanical) contact position indicator of the contacts of the mechanical isolating contact unit, -Free release, i.e., actuation to interrupt the contacts of the mechanical isolating contact unit by the handle or control unit is always possible, so that no (permanent) blocking of the contacts in the closed state by the handle is possible,

[0142] meant.

[0143] Furthermore, the standard-compliant disconnect function can include the ability to lock the disconnect contact unit or the handle in the switched-on or switched-off state.

[0144] The minimum air gap between the contacts of the isolating contact unit is essentially voltage-dependent. Other parameters include the degree of pollution, the type of field (homogeneous, inhomogeneous), and the air pressure or altitude above sea level.

[0145] There are corresponding regulations and standards for these minimum clearances or creepage distances. These regulations specify, for example, the minimum clearance for an inhomogeneous and a homogeneous (ideal) electric field in the context of air for impulse voltage resistance (see page 202422267).

[0146] 15

[0147] This depends on the degree of pollution. The impulse voltage withstand capability is the resistance to being subjected to a corresponding impulse voltage. Only if this minimum length (minimum distance) is present does the isolating contact unit or protective switching device exhibit an isolating function (isolating property).

[0148] For the purposes of the invention, the standards DIN EN 60947 and IEC 60947 are relevant for the separator function and its properties, and reference is made to them here.

[0149] The isolating contact unit is advantageously characterized by a minimum air gap between the open isolating contacts in the OFF position (open position, contacts open), depending on the rated impulse withstand voltage and the degree of pollution. The minimum air gap is, in particular, between (at a minimum) 0.01 mm and 14 mm.

[0150] In particular, the minimum air gap is advantageously between 0.01 mm at 0.33 kV and 14 mm at 12 kV, especially for pollution degree 1 and especially for inhomogeneous fields.

[0151] Advantageously, the minimum air gap can have the following values:

[0152] E DIN EN 60®47-1 (VDE 0-660-100} 2018-06

[0153] Table 13 - Minimum air distances

[0154] &

[0155]

[0156]

[0157] 202422267

[0158] 16

[0159] The pollution levels and field types correspond to those defined in the standards. This advantageously allows for the creation of a standard-compliant protective switching device dimensioned according to the rated impulse withstand voltage.

[0160] The term "mechanical isolating contact unit" specifically does not refer to a relay contact.

[0161] Figure 2 shows a representation according to Figure 1, with additional or different units shown.

[0162] In Figure 2, the power supply NT is part of the control unit SE. Furthermore, a (particularly wireless) communication unit COM is provided, which is connected to or part of the control unit SE.

[0163] Furthermore, a display unit AE is provided. The display unit AE can be designed as a combined display and input unit. The display unit AE (display and input unit) is connected to the control unit SE or is part of it. The display unit has visible indicators on the protective switching device, in particular for indicating the high-resistance or low-resistance state of the electronic interruption unit EU.

[0164] The electronic interruption unit EU is part of the control unit SE, as shown in Figure 2.

[0165] As shown in Figure 2, the control unit SE can include a microcontroller MP (microcontroller unit). The microcontroller can have various functions or routines / procedures, such as a configuration function KF, a switching logic function SF, and a protection function PF.

[0166] The protective switching device SG, for example, works in principle in such a way that when the contacts of the mechanical isolating contact unit and the low-resistance interruption unit are closed, and

[0167] - if a measured current exceeds a first current value, in particular if the first current value is exceeded for a first time limit, the electronic interruption unit EU becomes high-impedance and the mechanical disconnect contact unit MK remains closed, and / or

[0168] - (or / and) if a detected current exceeds a higher second current value, in particular for a second time limit, the electronic interruption unit EU becomes high-impedance and the mechanical disconnect contact unit MK opens, or / and 202422267

[0169] 17

[0170] - if the measured current exceeds an even higher third current value, the electronic interruption unit becomes high-resistance and the mechanical disconnect contact unit MK is opened.

[0171] The invention is described in more detail below, partly using different words.

[0172] Ripple control technology is a remote control system that uses the existing power grid. Control signals are transmitted via the power grid from central ripple control transmitters to decentralized ripple control receivers.

[0173] Electricity consumers typically receive information from energy supply companies (ESCs), for example, regarding the switch to off-peak electricity rates. Furthermore, the data serves for feed-in management as part of the legal obligation for decentralized electricity producers to participate in grid management.

[0174] In ripple control technology, data is transmitted unidirectionally at a very low data rate as a broadcast, and ripple control signals are centrally fed by the grid operator to a central point, such as a substation, for a large supply area, such as a city. Ripple control signals can be transmitted across multiple voltage levels, such as from the medium-voltage grid to the low-voltage grid.

[0175] The control commands are transmitted via pulse trains in the frequency range of 110 Hz to approximately 2000 Hz, superimposed on the mains voltage with an amplitude of approximately 1 to 4% of the respective nominal voltage. The utility company's own ripple control frequency is switched on and off according to a specific code (pulse grid) for transmission, thus generating a pulse telegram. Depending on the code used, these pulse grids have different structures and range in length from the shortest transit times of 6.6 seconds to the longest in the range of minutes.

[0176] Standards and VDE recommendations specify the criteria for dimensioning and operating a ripple control transmitter and the maximum permissible amplitude of the superimposed ripple control frequency. For example, the standard "EN 50 160" defines the limit values ​​and tolerances for voltage quality in public electricity supply networks. The ripple control frequency used by a German electricity supply company is proposed by the VDEW frequency consultant. Alternatively, radio-based ripple control technology is also available.

[0177] 18

[0178] In novel electronic protective switching devices, contacts (of a mechanical isolating contact unit) are used in combination with an electronic switch / semiconductor-based switching elements (an electronic interruption unit). The controllability of these switching elements by a ripple control signal is a novel way to expand the functions of the protective switching device. At the same time, the invention ensures that the controllability of the switching elements / the electronic interruption unit does not impair the safety-relevant protective functions of the protective switching device.

[0179] The control unit SE can switch the electronic interrupt unit EU into a high-resistance or low-resistance state, i.e., switch it on and off, as well as open the contacts (the contact) of the mechanical disconnect contact unit.

[0180] Furthermore, a handle (for opening and closing the isolating contact unit), a current measurement, advantageously a voltage measurement, and a power supply are provided. The protective switching device can perform various protection functions, such as short-circuit protection, overload protection, residual current protection, fire protection, overvoltage protection, undervoltage protection, and overtemperature protection.

[0181] Overload protection, for example, is protection against exceeding initial current and / or current-time limits. Short-circuit protection, for example, is protection against exceeding secondary (higher) current and / or current-time limits. Residual current protection, for example, is protection against exceeding differential current limits (e.g., 30 mA). Fire protection, for example, is the detection of series arc faults in low-voltage AC circuits. The same applies to overvoltage protection, undervoltage protection, and overtemperature protection.

[0182] According to the invention, a unit RE is provided for receiving a ripple control signal. The switching state of the electronic interrupt unit EU can be controlled by means of a received ripple control signal. Since the electronic interrupt unit EU is required, in particular, for performing protective functions PF, the control unit SE only forwards a ripple control signal to the electronic interrupt unit EU to make it low-impedance if none of the stored protective functions PF have detected a fault, i.e., if a release condition exists. In particular, if a fault is detected, i.e., if the electronic interrupt unit EU is in the high-impedance state, the ripple control signal cannot change this state (i.e., it cannot switch to low impedance).

[0183] 19

[0184] This means that the electronic interruption unit EU can only be switched to the low-impedance state using the ripple control signal if a release condition exists.

[0185] In particular, that in a high-impedance state of the electronic interruption unit EU caused by a protective function PF of the protective switching device, it cannot be switched to the low-impedance state by the ripple control signal.

[0186] A detected fault in the protective switching device refers specifically to a device malfunction, such as a defective current sensor unit, a defective interrupter, or overtemperature. Furthermore, this can also occur with external faults, such as overvoltage or undervoltage (the voltage falling below the RMS value for a certain period). Additionally, this can affect the normal protection functions PF, meaning that after current and / or current-time limits are exceeded and the current flow in the low-voltage AC circuit is interrupted, an immediate, forced low-impedance reduction via the ripple control signal is not possible, or not possible immediately.

[0187] The same applies to other internal device functions / circuit breaker-side verification functions, e.g., for device diagnostics or inrush handling. That is, circuit breaker-side verification functions that

[0188] a) switch an electronic interrupting unit EU in a high-impedance state to a low-impedance state for a first period of time or (and)

[0189] b) switch an electronic interruption unit EU in a low-impedance state to a high-impedance state for a second period of time,

[0190] are not affected by the ripple control signal.

[0191] These short switching operations can be used, for example, to test the electronic interrupt unit or to check the functionality of the current sensor unit.

[0192] These short switching operations are prioritized by the control unit SE or the switching logic function SF, so that an (external) ripple control signal cannot prevent these short switching operations.

[0193] The electronic interruption unit EU (or its switching elements) can only be controlled via the ripple control signal if the protective switching device is in a fault-free state and / or no fault has been detected at the load-side connection(s) (at the load output) (a release condition exists). This task is performed by the switching logic function SF. The ripple control signal cannot therefore directly control the electronic interruption unit (or its switching elements), but can only send a signal ESSI to the switching logic function SF to switch the 202422267 on or off.

[0194] 20

[0195] The electronic interrupt unit is sent. The switching logic function SF ensures that the protection functions PF always have priority over the electronic interrupt unit.

[0196] This applies not only to the protective functions PF of the protective switching device, but also to the verification functions of the protective switching device, which in particular check the switchability of the electronic interruption unit by switching it on or off, for example for the (short) first or second period of time.

[0197] Figure 3 shows a representation of a protective switching device according to Figures 1 and 2 in an embodiment with the differences mentioned below, in which further or other units are shown.

[0198] Figure 3 shows a split unit for receiving a ripple control signal, wherein the first voltage sensor unit SUA determines the ripple control signal from the measurement of the voltage of the low-voltage AC circuit or provides a signal with the ripple control signal to the control unit SE.

[0199] A filter FIL, such as a bandpass filter, is provided in the connection between the first voltage sensor unit SUA and the control unit SE, as shown in Figure 3. The filter FIL serves, for example, to filter out the ripple control signal from the low-voltage AC circuit, in particular from the voltage of the low-voltage AC circuit, specifically to filter out the control signal from the mains voltage waveform.

[0200] The control unit SE includes a receiver RX, which extracts the relevant control information from the ripple control signal, i.e., evaluates the ripple control signal and provides corresponding decisions for the protective switching device. The receiver RX may contain an analysis algorithm. A ripple control signal configuration unit RKF may be connected downstream of the receiver RX, which allows specific switching operations for the protective switching device to be configured when certain ripple control signals are present. For example, it may contain configuration data for controlling the protective switching device using the ripple control signal.

[0201] The unit for receiving the ripple control signal is therefore decentralized, i.e., different functions of the unit for receiving the ripple control signal are located in different units.

[0202] Figure 4 shows a further embodiment of the invention, a functional grouping for the microcontroller MP. The microcontroller MP receives the ripple control signal or information or signal ESSI (from the ripple control signal) for switching on or off. This is then processed by a 202422267

[0203] 21

[0204] The control signal configuration unit CSC receives the signal. Optionally, it can be configured here, for example, that the mechanical isolating contact unit MK is opened by an opening signal TRIP (open contact(s)) via the ripple control signal. The signal from the ripple control signal is then fed to the switching logic function SF. The switching logic function is further connected to protection functions PF, in this example to an internal protection function IPF for internal verification and reporting of the fault-free operation of the protective switching device, and an external protection function CPF, which monitors the low-voltage AC circuit and reports an overcurrent event, short circuit, etc. in the low-voltage AC circuit.

[0205] If the protective switching device has no internal fault, which is reported by the internal protection function IPF, and there is no external fault in the low-voltage AC circuit to be protected, which is reported by the external protection function CPF, both messages are sent to the switching logic function SF, a release condition exists and the electronic interrupt unit can be switched to a low-impedance or high-impedance state via the ripple control signal (connection of the switching logic function SF with the electronic interrupt unit EU (arrow pointing there).

[0206] The switching logic function SF in the protective switching device ensures that the protection functions PF, IPF, and CPF, which rely on the controllability of the electronic interrupt unit EU, can always switch it reliably when needed. When a protection function is active, the electronic interrupt unit cannot be controlled by the ripple control signal. If no protection state is active (release condition), controllability via the ripple control signal is reactivated for the electronic interrupt unit.

[0207] The same principle applies to internal device functions / internal protection functions (IPF). These internal protection functions (IPF) also access the electronic interruption unit. This can, for example, be just a brief switching operation for a device diagnostic function. While this function is being executed, control via the ripple control signal is temporarily unavailable.

[0208] The Control Signal Configuration Unit (CSC) allows you to configure what is done / should be done with the (digital) control signal.

[0209] For example, the electronic interruption unit EU can be controlled, or the mechanical disconnect contact unit, or both.

[0210] Figure 5 shows a configuration where the external protection function can control 3 states: 202422267

[0211] 22

[0212] A1 = mechanical disconnect contact unit, contact(s) open, electronic interrupt unit high resistance

[0213] S1 = mechanical disconnect contact unit, contact(s) closed, electronic interruption unit high resistance

[0214] E1 = mechanical disconnect contact unit, contact(s) closed, electronic interruption unit low resistance

[0215] The protective switching device is configured such that the contacts of the mechanical isolating contact unit MK are opened by means of the ripple control signal. This means that the ripple control signal (or signal ESSI) causes state A1.

[0216] Figure 6 shows a representation according to Figure 5, with the difference that the ripple control signal (or signal ESSI) causes a simple on / off switching, i.e., low-impedance / high-impedance state of the electronic interruption unit, by means of the switching logic function SF, whereby a high-impedance state occurs when a ripple control signal is present, which is characterized by state 1 in Figure 6, and when no ripple control signal is present, i.e., logic zero, a low-impedance state is to be initiated, which is characterized by state 0 in Figure 6.

[0217] The display unit has visible indicators on the protective switching device to indicate (display) the high-impedance or low-impedance state of the electronic interruption unit EU, for example by means of an LED display.

[0218] The contact position of the mechanical disconnect contact unit is indicated by the handle; this indication by the handle does not show the switching state of the electronic interruption unit.

[0219] In particular, the display of the switching state of the electronic interruption unit should occur when the switching state has been changed via the ripple control signal / is switched on or off.

[0220] The present invention allows a protective switching device to be extended relatively easily to a controllable mains connection. This eliminates the need for additional equipment. Integrating the function into the protective switching device saves space (in the distribution cabinet). Furthermore, additional installation costs are eliminated. 202422267

[0221] 23

[0222] Although the invention has been illustrated and described in detail by the exemplary embodiment, the invention is not limited by the disclosed examples and other variations can be derived from them by the person skilled in the art without leaving the scope of protection of the invention.

Claims

202422267 24 Patent claims 1. Protective switching device (SG) comprising for the protection of a low-voltage alternating current electrical circuit: - an enclosure (GEH) with at least two mains-side connections and at least two load-side connections, for connecting at least two conductors of the low-voltage alternating current circuit, - a mechanical isolating contact unit (MK) which can be switched by a closed state of the contacts to allow current flow in the conductors of the low-voltage alternating current circuit or by an open state of the contacts to prevent current flow by means of galvanic isolation of the conductors of the low-voltage alternating current circuit, - that the mechanical isolating contact unit (MK) is connected in series with an electronic interruption unit (EU), - that the electronic interruption unit (EU) can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow in at least one conductor or a low-resistance state of the switching elements to allow current flow in the low-voltage alternating current circuit, - a current sensor unit (Sl) for determining the magnitude of the current in the low-voltage alternating current circuit, - a control unit (SE) connected to the current sensor unit (Sl), the mechanical disconnect contact unit (MK) and the electronic interrupt unit (EU), wherein, if current and / or current time limits are exceeded, a current flow prevention of the low-voltage AC circuit is initiated, - that a unit (RE) for receiving a ripple control signal is provided on the protective switching device (SG), - that the protective switching device is designed in such a way, that the electronic interrupt unit (EU) can be switched to a high-impedance or low-impedance state by means of a ripple control signal.

2. Protective switching device (SG) according to claim 1, characterized by that the mechanical isolating contact unit (MK) is assigned to the load-side connection and the electronic interruption unit (EU) to the network-side connection, in particular that the mechanical isolating contact unit (MK) can be operated by a mechanical handle to switch the opening or closing of contacts. 202422267 25 3. Protective switching device (SG) according to claim 1 or 2, characterized by that a first voltage sensor unit (SUA) connected to the control unit (SE) is provided for determining the voltage level of the low-voltage alternating current circuit, that the ripple control signal is determined from the measurement of the voltage of the low-voltage alternating current circuit.

4. Protective switching device (SG) according to claim 1, 2 or 3, characterized by that the unit for receiving the ripple control signal has a filter, in particular a bandpass filter, for filtering out the ripple control signal from the low-voltage alternating current circuit, in particular from the voltage of the low-voltage alternating current circuit.

5. Protective switching device (SG) according to one of the preceding patent claims, characterized by that a ripple control signal configuration unit RKF is provided for the configurable controllability of the protective switching device by means of the ripple control signal.

6. Protective switching device (SG) according to one of the preceding patent claims, characterized by that the electronic interruption unit (EU) can only be switched to a low-impedance state by means of the ripple control signal if a release condition exists, in particular that in the case of a high-impedance state of the electronic interruption unit (EU) caused by a protective function of the protective switching device, it cannot be switched to the low-impedance state by means of the ripple control signal.

7. Protective switching device (SG) according to one of the preceding patent claims, characterized by that protection switch-side verification functions that a) switch an electronic interrupting unit (EU) in a high-impedance state to a low-impedance state for a first period of time or b) a low-impedance electronic interruption unit (EU) for 202422267 26 switch to a high-impedance state for a second period of time, are not affected by the ripple control signal.

8. Protective switching device (SG) according to one of the preceding patent claims, characterized by that the contacts of the mechanical isolating contact unit (MK) can be opened by means of the ripple control signal, In particular, it is configurable whether the ripple control signal is used. a) the electronic interruption unit (EU) is switchable to a high-resistance or low-resistance state or b) the contacts of the mechanical isolating contact unit (MK) are openable.

9. Protective switching device (SG) according to one of the preceding patent claims, characterized by that a display unit connected to the control unit (SE) is provided, which has visible display means on the protective switching device, for indicating the high-resistance or low-resistance state of the electronic interruption unit (EU).

10. Protective switching device (SG) according to one of the preceding patent claims, characterized by that the protective switching device is designed in such a way, that in the case of a high-impedance state of the electronic interruption unit initiated by the ripple control signal, this high-impedance state of the electronic interruption unit is established at the current zero crossing.

11. Protective switching device (SG) according to one of the preceding claims 3 to 9 in conjunction with claim 3, characterized by that the first voltage sensor unit (SUA) determines instantaneous values ​​of the voltage level, that the protective switching device is designed in such a way, that, in the case of a low-impedance state of the electronic interruption unit initiated by the ripple control signal, this low-impedance state of the electronic interruption unit is established at the voltage zero crossing and / or that in a high-impedance state of the electronic202422267 initiated by the ripple control signal 27 The interruption unit establishes this high-resistance state of the electronic interruption unit at the voltage zero crossing.

12. Method for a protective switching device (SG) for the protection of a low-voltage alternating current electrical circuit with at least two conductors, with - a mechanical isolating contact unit (MK) which can be switched by a closed state of the contacts for current flow in the conductors of the low-voltage alternating current circuit or by an open state of the contacts to prevent current flow by means of galvanic isolation of the conductors of the low-voltage alternating current circuit, - that the mechanical disconnect contact unit (MK) is connected in series with an electronic interruption unit (EU), - that the electronic interruption unit (EU) can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow in at least one conductor or a low-resistance state of the switching elements to allow current flow in the low-voltage alternating current circuit, - that the magnitude of the current in the low-voltage alternating current circuit is determined and, if current and / or current time limits are exceeded, a measure to prevent current flow in the low-voltage alternating current circuit is initiated. - that the electronic interrupt unit (EU) can be switched to a high-impedance or low-impedance state by means of a ripple control signal.

13. Method according to claim 12, characterized by that the electronic interruption unit (EU) is only switched to a low-impedance state by means of the ripple control signal if a release condition exists, in particular that in the case of a high-impedance state of the electronic interruption unit (EU) caused by a protective function of the protective switching device, it cannot be switched to the low-impedance state by the ripple control signal.

14. Method according to claim 12 or 13, characterized by that protection switch-side verification functions that a) switch an electronic interrupting unit (EU) in a high-impedance state to a low-impedance state for a first period of time or b) a low-impedance electronic interruption unit (EU) for 202422267 28 Switch to a high-impedance state for a second period of time, which will not be affected by the ripple control signal.

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