Circuit breaker device and method

Abstract

The invention relates to a circuit breaker device for protecting an electric multi-phase low-voltage alternating current circuit, comprising: - a housing comprising grid-side phase connections and load-side phase connections for phase conductors of the low-voltage alternating current circuit, and - series circuits consisting of a mechanical phase contact and an electronic switch, wherein each series circuit electrically connects a respective grid-side phase connection to one of the load-side phase connections, - the mechanical phase contacts are switched together to an open state in order to prevent a current flow or to a closed state for a current flow, - by means of semiconductor-based switch elements, the electronic switches are switched to a high-ohmic state of the switch elements in order to prevent a current flow or to a low-ohmic state of the switch elements for a current flow, - in each series circuit, the level of the current of the respective phase conductor is ascertained, - if at least one first current threshold or current / time threshold is exceeded in a phase conductor, a prevention of a current flow is initiated, and - the electronic switches can be switched to a high-ohmic or low-ohmic state by means of a control input.

Description

[0001] Description

[0002] Protective switching device and procedure

[0003] The invention relates to the technical field of a protective switching device for a multi-phase low-voltage alternating current circuit with electronic switches and a method for a protective switching device for a multi-phase low-voltage alternating current circuit with electronic switches.

[0004] Low voltage refers to voltages of up to 1000 volts AC or up to 1500 volts DC. Low voltage refers in particular to voltages greater than extra-low voltage, with values ​​of 50 volts AC or 120 volts DC.

[0005] The term low-voltage circuit, network or system refers to circuits with nominal or rated currents of up to 125 amperes, more specifically up to 63 amperes. The term low-voltage circuit particularly refers to circuits with nominal or rated currents of up to 50 amperes, 40 amperes, 32 amperes, 25 amperes, 16 amperes or 10 amperes. The current values ​​mentioned refer in particular to nominal, rated and / or breaking currents, i.e. the maximum current that is normally carried through the circuit or at which the electrical circuit is usually interrupted, for example by a protective device such as a protective switching device, circuit breaker or circuit breaker. The rated currents can be further staggered, from 0.5 A to 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.

[0006] Miniature circuit breakers are long-established overcurrent protection devices used in low-voltage electrical circuits. They protect cables from damage caused by overheating due to excessive current and / or short circuits. A miniature circuit breaker can automatically disconnect the circuit in the event of an overload and / or short circuit. A miniature circuit breaker is a non-self-resetting fuse element.

[0007] Unlike miniature circuit breakers, circuit breakers are designed for currents greater than 125 A, and in some cases even as low as 63 A. Miniature circuit breakers are therefore simpler and more delicate in design. Miniature circuit breakers typically have a mounting option for mounting on a so-called top-hat rail (support rail, DIN rail, TH35).

[0008] Miniature circuit breakers are electromechanical in design. They contain a mechanical switching contact or shunt release in a housing to interrupt (trip) the electrical current. A bimetallic protective element or bimetallic element is usually used to trip (interrupt) the circuit in the event of a prolonged overcurrent (overcurrent protection) or thermal overload (overload protection). An electromagnetic release with a coil is used for brief 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 for arc quenching are provided. There are also connection elements for conductors of the electrical circuit to be protected.

[0009] Protective switching devices with an electronic interruption unit or an electronic switch are relatively new developments. These have a semiconductor-based electronic interruption unit or a semiconductor-based electronic switch. This means that the electrical current flow in the low-voltage circuit is guided via semiconductor components or semiconductor switches, which interrupt the electrical current flow or can be switched to conduction. Protective switching devices with an electronic interruption unit also often have a mechanical isolating contact unit, in particular with isolating properties in accordance with the relevant standards for low-voltage circuits, with the contacts of the mechanical isolating contact unit being connected in series to the electronic interruption unit, i.e.The current of the low-voltage circuit to be protected is conducted via both the mechanical isolating contact unit and the electronic interruption unit.

[0010] The present invention relates in particular to (multiphase) low-voltage alternating current circuits, with a

[0011] Alternating voltage, usually with a time-dependent sinusoidal alternating voltage with frequency f. The time dependence of the instantaneous voltage value u(t) of the alternating voltage is described by the equation: u(t) = U * sin (2n * f * t). Where: u(t) = instantaneous voltage value at time t

[0012] U = amplitude of the voltage

[0013] A harmonic alternating voltage can be represented by the rotation of a pointer whose length corresponds to the amplitude (U) of the voltage. The instantaneous deflection is the projection of the pointer onto a coordinate system. One oscillation period corresponds to one full rotation of the pointer, and its full angle is 2n (2Pi) or 360°. The angular frequency is the rate of change of the phase angle of this rotating pointer. The angular frequency of a harmonic oscillation is always 2n times its frequency, i.e.: w = 2n*f = 2n / T = angular frequency of the alternating voltage (T = period of the oscillation)

[0014] Often, the specification of the angular frequency (w) is preferred over the frequency (f), since many formulas of oscillation theory can be represented more compactly using the angular frequency due to the occurrence of trigonometric functions whose period is by definition 2n: u ( t ) = U * sin (wt)

[0015] In the case of angular frequencies that are not constant over time, the term instantaneous angular frequency is also used.

[0016] In the case of a sinusoidal, in particular temporally 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 referred to as the phase angle cp ( t ). This means that the phase angle cp ( t ) periodically passes through the range O...2n or 0°...360°. This means that the phase angle periodically assumes a value between 0 and 2n or 0° and 360° (cp = n* (0...2n) or cp = n* ( 0 °...360 ° ) , due to periodicity; in short: cp = O...2n or cp = 0°...360° ).

[0017] The instantaneous voltage value u(t) is therefore the instantaneous value of the voltage at time t, ie in the case of a sinusoidal (periodic) alternating voltage, the value of the voltage at the phase angle cp (cp = 0...2n or cp = 0°...360°, of the respective period).

[0018] The object of the present invention is to improve a protective switching device of the type mentioned above, in particular to achieve greater flexibility or a new feature for the protective switching device.

[0019] This object is achieved by a protective switching device having the features of patent claim 1 and by a method according to patent claim 20.

[0020] According to the invention, a protective switching device for protecting an electrical multi-phase low-voltage alternating current circuit is proposed, comprising:

[0021] - a housing with mains-side phase connections and load-side phase connections for phase conductors of the multi-phase low-voltage alternating current circuit,

[0022] - Series circuits of a mechanical phase contact and an electronic switch, each of which electrically connects one of the mains-side phase connections to one of the load-side phase connections,

[0023] - that the mechanical phase contacts can be switched together to open in order to avoid a current flow or together to close in order to avoid a current flow,

[0024] - that the electronic switches can be switched by means of semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow or into a low-resistance state of the switching elements to allow current flow,

[0025] - that for each series circuit, a current sensor unit is provided for determining the current level of the respective phase conductor, in particular in such a way that instantaneous current values ​​are available,

[0026] - that a control unit is provided which is connected to the current sensor units, the mechanical phase contacts and the electronic switches, that the protective switching device is designed in such a way that when at least one first current threshold value and / or current time limit value in a phase conductor is exceeded, an avoidance of a current flow is initiated, in particular by the electronic switches,

[0027] - that a control input is provided on the protective switching device,

[0028] - that the protective switching device is designed in such a way that the electronic switches can be switched into a high-resistance or low-resistance state by means of the control input.

[0029] In particular, all electronic switches can be switched simultaneously into a high-impedance or low-impedance state via the control input. This has the advantage that a control input is provided for a multi-phase protective switching device, with which the electronic switches can be switched explicitly. Usually, only the mechanical (phase) contacts can be switched using a handle accessible on the protective switching device. External (control input) switchability of the electronic switches is not usually provided. The invention makes this possible externally and provides an opportunity to expand the functions of a protective switching device.

[0030] Further advantageous embodiments of the invention are specified in the subclaims and in the exemplary embodiment.

[0031] In an advantageous embodiment of the invention, the protective switching device is designed in such a way that the electronic switches can be switched independently of one another into a high-resistance or low-resistance state by means of the control input.

[0032] Alternatively or additionally, each electronic switch can be switched individually (or in pairs), for example by means of a (particularly configurable) switching sequence; this can in particular be configurable.

[0033] This has the particular advantage that phase-related switchability (the electronic switches can be switched to a high-resistance or low-resistance state independently of each other for each phase) provides increased flexibility for the protective switching device, which enables new functions.

[0034] In an advantageous embodiment of the invention, the protective switching device is designed in such a way that when at least a first current threshold value in a phase conductor is exceeded, the relevant electronic switch initiates the avoidance of a current flow in the relevant phase conductor, in particular for a first period of time.

[0035] This has the particular advantage that when a specified current threshold or a current-time threshold is exceeded (i.e., the current threshold is exceeded for a defined period of time), a selective interruption occurs only in the affected conductor(s). Current flow is still permitted in the other conductors (unaffected conductors) in a multi-phase low-voltage AC circuit.

[0036] By avoiding this for an initial period, the device can be switched on again or become low-impedance after the initial period, thus ensuring continued security of supply and allowing further testing to determine whether the current threshold has been exceeded. This can be achieved particularly advantageously by evaluating instantaneous current values.

[0037] This advantageously provides increased supply reliability, as it does not initiate complete current avoidance, but rather only phase-specific current avoidance. Furthermore, short-term current peaks can be absorbed, and even if there is no fault in the low-voltage circuit, false shutdowns can be avoided.

[0038] In an advantageous embodiment of the invention, the first time period is less than 20 ms, in particular less than 10 ms.

[0039] This has the particular advantage that an interruption occurs for a half-wave or full-wave of the voltage or current in the alternating current circuit (in the example (20 ms, 10 ms) based on a mains frequency of 50 Hz), so that the electrical supply security is restored with the next full-wave or half-wave. In particular, after an interruption, the low-resistance can occur in the area of ​​the next zero crossing (at the zero crossing or in the range of 1 ms before or after).

[0040] In an advantageous embodiment of the invention, the mechanical phase contacts are assigned to the load-side connection, and the electronic switches are assigned to the mains-side connection. In particular, the mechanical phase contacts can be operated by a mechanical handle to open or close the contacts. In particular, the mechanical phase contacts are part of a mechanical isolating contact unit that switches the phase contacts together.

[0041] This has the particular advantage of providing a structure for a protective switching device that ensures its functionality even when the contacts of the mechanical isolating contact unit are open. This provides an advantageous design that supports phase-related switching of the electronic switches and enables self-testing (in particular, self-testing of the electronic switches), even when the contacts are open. Furthermore, a power supply to the protective switching device is ensured, even when the contacts are open.

[0042] Another particular advantage is that complete galvanic isolation of all phase conductors is achieved simultaneously (in contrast to phase-specific high-resistance electronic switches that prevent current flow). This operation enables compatible behavior with conventional electromechanical protective switching devices.

[0043] In an advantageous embodiment of the invention, the control input has a particularly safe galvanic isolation, particularly between the control input and the phase conductors. More specifically, between the control input and the low-voltage circuit (the voltage of the low-voltage circuit present in the device).

[0044] Furthermore, more specifically, a safe, galvanic isolation between the control input and the control unit.

[0045] Safe galvanic isolation can be achieved, for example, by means of an optocoupler or relay. Alternatively, by inductive or capacitive galvanic isolation. This has the particular advantage that the control input can be used universally without any potential and that safe galvanic isolation from the phase conductors (or the control unit) is provided. Since the phase conductors (or the control unit) are at mains voltage during operation (e.g. 230 V (AC)), this galvanic isolation enables safe use of the control input. In particular, this provides protection against electric shock or so-called "voltage carryover" to a connected electrical cable and the devices connected to it. In the case of voltage carryover, an electrical potential is unintentionally transferred to an electrical cable or another device.

[0046] This has the particular advantage that the protective switching device can be used universally and potential-free, and that a safe galvanic isolation from the phase conductors (or the control unit) is provided.

[0047] In an advantageous embodiment of the invention, the electronic switches can only be switched to a low-impedance state by means of the control input if an enabling condition exists. In particular, if an electronic switch is in a high-impedance state due to a (particularly external) protective function of the protective switching device, this electronic switch (alternatively, all electronic switches, i.e., the electronic switches) cannot be switched to the low-impedance state by the control input (particularly at least not within a first period of time after becoming high-impedance).

[0048] The first time period can be 10 seconds or more.

[0049] This has the particular advantage that the basic function of the protective switching device - to provide protection - is not influenced by the control input and, for example, a defective protective switching device (no release condition) cannot be forcibly switched on by the control input, i.e. the low-voltage circuit is supplied with energy without protection.

[0050] Furthermore, in particular in the case of a high-impedance state of one or more electronic switches caused by a protective function of the protective switching device (e.g., upon / after exceeding current and / or current-time limit values), this high-impedance state cannot be changed by the control input, i.e., the low-impedance state can be forcibly (immediately) switched back on. This means that the protective switching device cannot simply be switched back to low-impedance after a protective function.

[0051] In an advantageous embodiment of the invention, checking functions on the circuit breaker side which a) switch an electronic switch in the high-resistance state to the low-resistance state for a first period of time or (and) b) switch an electronic switch in the low-resistance state to the high-resistance state for a second period of time cannot be influenced by the control input (i.e. the checking functions are carried out independently of the (status of the) control input).

[0052] This has the particular advantage that the control input does not influence the testing functions of the protective switching device, thus ensuring functional reliability, particularly through testing functions (during operation) of the protective switching device.

[0053] The first time period is, for example, a short time period in the range of ps or ms up to one second, such as l O Ops ... 200ps ... 300ps ... 600ps ... 700ps ... 800ps ... 1ms ... 10ms ... 20ms ... 40ms ... 50ms ... 100ms ... 200ms ... 500ms ... 1 s (any intermediate value is possible).

[0054] The second time span is, for example, a short time span in the range of ps or ms up to one second, such as l O Ops ... 200ps ... 300ps ... 600ps ... 700ps ... 800ps ... 1ms ... 10ms ... 20ms ... 40ms ... 50ms ... 100ms ... 200ms ... 500ms ... 1 s (any intermediate value is possible).

[0055] In an advantageous embodiment of the invention, the phase contacts can be opened by means of the control input, in particular it is configurable whether by means of the control input a) the electronic switches can be switched to a high-resistance or low-resistance state or b) the phase contacts (if applicable of the mechanical isolating contact unit) can be opened.

[0056] Alternatively or additionally, for example, one or the other state can be initiated by a (particularly configurable) switching sequence; this can in particular be configurable.

[0057] This has the particular advantage of providing further flexibility and functional expansion of the protective switching device.

[0058] In an advantageous embodiment of the invention, the control input is accessible from the housing. In particular, the control input has a plurality of connection terminals, in particular two, three, or four connection terminals, wherein the connection terminals are connected internally to at least one optocoupler within the circuit breaker.

[0059] Furthermore, this control input provides a wired interface (in particular, a two-, three-, or four-wire wired communication interface), enabling virtually delay-free signaling through the control input (largely latency-free). "Qualistically delay-free" refers to direct signaling, i.e., without overhead-related information processing, such as that inherent in LAN / WLAN connections, using communication protocols such as MAC addresses, TCP / IP communication, or OS I communication.

[0060] This has the particular advantage of providing a simple way to connect the control input. Furthermore, with four connection terminals, each electronic switch can be switched independently (and directly), which is advantageous, for example, in a three-phase AC circuit (a common variant of a multi-phase low-voltage AC circuit).

[0061] In an advantageous embodiment of the invention, a display unit connected to the control unit is provided, which has display means visible on the protective switching device for displaying the high-resistance or low-resistance state of the electronic switches.

[0062] The state of each electronic switch can be displayed. Alternatively, a total state (high-resistance / low-resistance) of the electronic switches can be displayed, based on defined criteria or, if the electronic switches are connected together (only one total state: high-resistance or low-resistance), only one common state can be displayed.

[0063] This has the particular advantage that a visualization of the state of the electronic switches (or their common switching state) is provided.

[0064] In an advantageous embodiment of the invention, the protective switching device is designed such that in the case of a (change to) STANDBY state (standby state) initiated by the control input, in which all electronic switches are in the high-impedance state (with closed contacts), this high-impedance state is established when the current of the respective electronic switch passes through zero. This means that in the case of, for example, a three-phase alternating current circuit with, for example, resistive loads one after the other (120° phase shift) at the respective current zero crossing.

[0065] At current zero crossing (= in the area of ​​current zero crossing) means directly at current zero crossing or in its vicinity, i.e. for example at an instantaneous value of the current 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 circuit or protective switching device, for example 20% ... 15% ... 10% ... 5% ... 1% or less of the rated current).

[0066] This has the particular advantage of supporting virtually powerless switching, thus reducing the load on the electronic switches, particularly their semiconductor-based switching elements. In an advantageous embodiment of the invention, a mains-side neutral conductor connection and a load-side neutral conductor connection are provided on the housing for a neutral conductor of the multi-phase low-voltage AC circuit.

[0067] The mains-side neutral conductor connection is connected to the load-side neutral conductor connection directly or via a mechanical neutral conductor contact.

[0068] This has the particular advantage of providing a multi-pole protective switching device in which the neutral conductor is also galvanically interrupted if necessary.

[0069] In an advantageous embodiment of the invention, the mechanical neutral conductor contact can be opened or closed together with the phase contacts. In particular, the neutral conductor contact is closed before the phase contacts are closed, or the neutral conductor contact is opened after the phase contacts are opened.

[0070] This has the particular advantage that the neutral conductor contact always opens and closes without current. This reduces contact wear and increases its service life. Furthermore, it prevents the occurrence of an arc when the neutral conductor contact opens.

[0071] In an advantageous embodiment of the invention, a voltage sensor unit is provided between each phase conductor and the neutral conductor to determine the voltage level between the respective phase and neutral conductors, in particular the instantaneous voltage values. The voltage sensor units are connected to the control unit.

[0072] In an advantageous further development of the embodiment, the protective switching device is designed in such a way that when the control unit, in particular the control input, initiates a low-resistance event (in particular in the absence of an overcurrent event, i.e. when the first or a second current threshold is not exceeded; e.g. when the user initiates a low-resistance event via the control input), the (all) electronic switches become low-resistance, in particular one after the other, at the respective zero crossing of the voltage (i.e. at a voltage which is less than 50V, 25V, in particular less than 10V).

[0073] A (particularly initiated) low-resistance state of (all) electronic switches (with (at the same time / simultaneously) closed contacts) is also called an ON state or On state.

[0074] This has the particular advantage of reducing grid perturbations and lowering the switching load on the switch. Furthermore, it supports further, virtually powerless switching, thus reducing the load on the electronic switches, especially their semiconductor-based switching elements.

[0075] At the voltage zero crossing (= in the area of ​​the voltage zero crossing) means directly at the voltage zero crossing or in its vicinity, ie for example at an instantaneous value of the voltage which is smaller than a first voltage limit, for example which is smaller than 10 volts, 25 volts or 50 volts (any intermediate value or smaller value is possible).

[0076] In an advantageous embodiment of the invention, the protective switching device is designed such that when the control unit, in particular the control input, initiates a high-impedance event (in particular in the absence of an overcurrent event, ie when the first or second current threshold is not exceeded; e.g. when the user initiates a high-impedance event via the control input), the (all) electronic switches become high-impedance, in particular one after the other, at the respective zero crossing of the voltage (or at a voltage which is less than 50V, 25V, in particular less than 10V).

[0077] A (particularly initiated) high-impedance state of (all) electronic switches (with (simultaneous) closed contacts) is also referred to as a STANDBY state or standby state. An open state of the mechanical contacts (particularly with a high-impedance state of the electronic switches) is also referred to as an OFF state or off state.

[0078] This has the particular advantage of reducing system perturbations and lowering the switching load on the switch. Furthermore, it supports further, virtually powerless switching, thus reducing the load on the electronic switches, particularly their semiconductor-based switching elements.

[0079] At the voltage zero crossing means directly at the voltage zero crossing or in its vicinity, i.e. for example at an instantaneous value of the voltage which is smaller than a first voltage limit, for example which is smaller than 10 volts, 25 volts or 50 volts (any intermediate or smaller value is possible).

[0080] In an advantageous embodiment of the invention, the protective switching device is designed such that, when the first current threshold in a conductor is exceeded, the relevant electronic switch initiates a current flow prevention in the relevant conductor. At the next or subsequent zero crossing of the voltage, the electronic switch becomes low-resistance again to allow current flow. The control unit is connected to the current sensor units, the voltage sensor units, the mechanical (phase) contacts, and the electronic switches.

[0081] This has the particular advantage that increased robustness against false triggering is achieved and thus increased electrical supply reliability is achieved.

[0082] In an advantageous embodiment of the invention, the protective switching device is designed such that the control input: a) initiates the high-resistance state of the electronic switch(es) when a first voltage level is applied, or the low-resistance state when a second voltage level is applied, or b) initiates the state change between the high-resistance or low-resistance state or low-resistance or high-resistance state of the electronic switch(es) when a third voltage level is applied for a first period of time, or c) initiates a change of the electronic switch(es) to the low-resistance state when a third voltage level is applied for a second period of time, and after a third period of time, which can be set in particular, the electronic switch(es) changes to the high-resistance state.

[0083] This has the particular advantage that various switching options are available, which can be advantageously configured, for example.

[0084] A voltage level refers specifically to a voltage range, such as (low-voltage) TTL voltage levels with voltage ranges such as a first voltage level (logical zero) with 0 volts to 0.8 volts and a second voltage level (logical one) with 2 volts to 3.3 volts.

[0085] In an advantageous embodiment of the invention, the protective switching device is designed in such a way that an acknowledgment of a fault-related high-resistance state of at least one electronic switch, in particular that the fault-related high-resistance state was initiated by the current and / or current time limit values ​​in the low-voltage circuit being exceeded, takes place by means of the control input, so that the electronic switches can be switched to the low-resistance state if there is subsequently no fault or switch automatically to the low-resistance state, in particular that it is configurable whether by means of the control input a) the electronic switches can be switched to a high-resistance or low-resistance state or b) an acknowledgment of a fault-related high-resistance state takes place.

[0086] This has the particular advantage of providing additional functionality for the protective switching device. According to the invention, a corresponding method for a protective switching device for a multi-phase low-voltage AC circuit with electronic (semiconductor-based) switches with the same and additional advantages is claimed.

[0087] The method for a protective switching device for protecting a multi-phase low voltage alternating current electrical circuit with :

[0088] - a housing with mains-side phase connections and load-side phase connections for phase conductors of the low-voltage alternating current circuit,

[0089] - Series circuits of a mechanical phase contact and an electronic switch, each of which electrically connects one of the mains-side phase connections to one of the load-side phase connections,

[0090] - that the mechanical phase contacts are switched together to open to avoid current flow or together to close to avoid current flow,

[0091] - that the electronic switches are switched by means of semiconductor-based switching elements into 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,

[0092] - that in each series circuit the current level of the respective phase conductor is determined, in particular in such a way that instantaneous current values ​​are available,

[0093] - that if at least one first current threshold or current time limit in a phase conductor is exceeded, the avoidance of a current flow is initiated, in particular by the electronic switches,

[0094] - that the electronic switches can be switched to a high-impedance or low-impedance state by means of a control input.

[0095] In an advantageous embodiment, the electronic switches are switched to a low-resistance state by means of the control input only when an enabling condition exists. In particular, if at least one electronic switch is in a high-resistance state due to a protective function of the protective switching device, the electronic switches cannot be switched to the low-resistance state by the control input.

[0096] In an advantageous embodiment, checking functions on the circuit breaker side which a) switch an electronic switch in the high-resistance state to the low-resistance state for a first period of time or b) switch an electronic switch in the low-resistance state to the high-resistance state for a second period of time are not influenced by the control input.

[0097] All embodiments, both in dependent form referring back to patent claim 1 or 20, and 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), bring about an improvement in a protective switching device, in particular an improvement in functionality and provide a new feature and concept for a protective switching device.

[0098] The described properties, features and advantages of this invention as well as the manner in which these are achieved will become clearer and more clearly understandable in connection with the following description of the embodiments, which are explained in more detail in connection with the drawing.

[0099] The drawing shows:

[0100] Figure 1 shows a first representation of a protective switching device,

[0101] Figure 2 shows a second representation of a protective switching device, Figure 3 shows a third representation of a protective switching device.

[0102] Figure 4 shows a fourth representation of a protective switching device,

[0103] Figure 5 shows a representation of a control input,

[0104] Figure 6 shows a representation of a functional grouping,

[0105] Figure 7 shows a representation of a first configuration,

[0106] Figure 8 shows a representation of a second configuration,

[0107] Figure 9 shows a representation of a third configuration,

[0108] Figure 10 shows a representation of a fourth configuration.

[0109] Figure 1 shows an exemplary representation of a 3-pole, e.g. for 3-phase conductors, protective switching device SG for protecting an electrical multi-phase low-voltage alternating current circuit, in the example according to Figure 1 a three-phase low-voltage alternating current circuit, comprising:

[0110] - a housing GEH with a first, second and third mains-side phase connection LG1, LG2, LG3 and a first, second and third load-side phase connection LL1, LL2, LL3, for the first, second and third phase conductors LI, L2, L3 of the low-voltage alternating current circuit, an energy source is usually connected to the mains side Grid, and a consumer is usually connected to the load side Load.

[0111] In the housing GEH :

[0112] - a first series circuit SS1 of a first mechanical phase contact K1 and a first electronic switch S1, a second series circuit SS2 of a second mechanical phase contact K2 and a second electronic switch S2, a third series circuit SS3 of a third mechanical phase contact K3 and a third electronic switch S3, wherein: the first series circuit SS1 electrically connects the first mains-side phase connection LG1 to the first load-side phase connection LL1, the second series circuit SS2 electrically connects the second mains-side phase connection LG2 to the second load-side phase connection LL2, and the third series circuit SS3 electrically connects the third mains-side phase connection LG3 to the third load-side phase connection LL3,

[0113] - the mechanical phase contacts Kl, K2, K3 can be switched together, ie they are opened together to prevent a current flow or closed together to allow a current flow, ie the mechanical contacts are connected to each other via mechanical coupling (e.g. switching shaft),

[0114] - the electronic switches SI, S2, S3 can be switched by means of semiconductor-based switching elements into 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.

[0115] According to the invention, a control input CI is provided on the protective switching device SG. The protective switching device SG is designed such that the electronic switches SI, S2, S3 can be switched to a high-impedance or low-impedance state using the control input CI.

[0116] In particular (in a simple variant) all electronic switches SI, S2, S3 can be switched simultaneously to the high-impedance or low-impedance state via the control input CI.

[0117] According to Figure 1, a first, second, and third current sensor unit SI1, SI2, SI3 are provided. The first current sensor unit SI1 is provided or arranged in the first series circuit SS1, the second current sensor unit SI2 is provided or arranged in the second series circuit SS2, and the third current sensor unit SI3 is provided or arranged in the third series circuit SS3, for respectively determining the magnitude of the current of the first, second, and third phase conductors LI, L2, L3, in particular the instantaneous current values.

[0118] The first mechanical phase contact K1, the second mechanical phase contact K2 and the third mechanical phase contact K3 are, according to Figure 1, part of a mechanical isolating contact unit MK, which opens or closes the phase contacts K1, K2, K3 together. The mechanical isolating contact unit MK can have a handle HH accessible on the protective switching device for manual (operated by a person) opening or closing of the phase contacts. The mechanical isolating contact unit MK corresponds, for example, to a classic unit, as is known from electromechanical protective switching devices (circuit breakers, power breakers) (although according to the invention without elements for overcurrent or short-circuit detection, such as bimetallic releases, etc.).

[0119] The protective switching device is in particular designed in such a way that the mechanical phase contacts or the mechanical isolating contact unit MK can be opened but not closed by a control unit SE. In particular, the mechanical contacts can only be closed by the handle HH after release by the control unit SE. A release unit LC can be provided for this purpose. This means that the contacts can only be closed by the handle HH when release or a release signal (from the control unit) is present. Without the release or the release signal, the handle HH can be operated, but the contacts cannot be closed ("continuous slipping").The release unit LC can further be designed in such a way that the contacts Kl, K2, K3 of the mechanical isolating contact unit MK can be opened by a control signal from the control unit SE, as indicated in Figure 1 by an arrow from the control unit SE to the release unit LC.

[0120] According to Figure 1, the mechanical phase contacts Kl, K2, K3 are assigned to the load-side phase connections / the load side Load and the electronic switches SI, S2, S3 are assigned to the grid-side phase connections / grid side Grid.

[0121] The first electronic switch S1, the second electronic switch S2 and the third electronic switch S3 can be part of an electronic interruption unit EU, wherein the electronic switches S1, S2, S3 can in particular be switched independently of one another.

[0122] The electronic interruption unit / electronic switches can have bidirectional dielectric strength. Overvoltage protection is specifically provided for the semiconductor-based switching elements to limit the voltages and thus protect the semiconductor-based switching elements.

[0123] A control unit SE is provided (as already partially mentioned), which is connected to the current sensor units S11, S12, S13, the mechanical phase contacts (K1, K2, K3) or the mechanical isolating contact unit MK (as shown in Figure 1), and the electronic switches S1, S2, S3. The control input CI is connected to the control unit SE, as shown as an example in Figure 1.

[0124] The current sensor units Sil, SI2, SI3 each determine the level of the current of their respective (phase) conductor, so that instantaneous values ​​of the current are available.

[0125] If at least a first current threshold value or current-time limit value is exceeded in (at least) one conductor, avoidance of a current flow is initiated. In one variant, the avoidance of the current flow can take place in the conductor in question (in which the first current threshold value or current-time limit value has been exceeded). In another variant, the avoidance of the current flow can take place in all phase conductors (or alternatively in all conductors in which an electronic switch is provided). The avoidance of the current flow takes place in particular by the electronic switch(es) (depending on the configuration) becoming high-impedance. If at least a second (higher) current threshold value or current-time limit value (higher or longer current-time value compared to the first current-time limit value) is exceeded in (at least) one conductor, a current flow can be avoided by opening the contacts Kl, K2, K3.

[0126] This high-resistance condition can occur, in particular, for an initial period of time. After this period, the relevant electronic switch(es) can return to low-resistance. Overcurrent events (current threshold exceeded) can be handled per phase / phase conductor. This also protects the electronic switches from overload.

[0127] The low-resistance condition can occur, in particular, at the next zero crossing, or before or after the zero crossing of the voltage. (All three options: at the zero crossing, before the zero crossing, or after the zero crossing - are possible, or when the voltage falls below a certain threshold, in particular 50V, 25V, or 10V).

[0128] The first time period may in particular be less than 20 ms, especially less than 10 ms.

[0129] A differential current sensor unit ZCT can be provided, as shown in Figure 1, for detecting differential currents in the low-voltage AC circuit, such as those found in residual current circuit breakers. The differential current sensor unit ZCT is connected to the control unit SE.

[0130] 1, the current sensor units Sil, SI2, SI3 are arranged between the mains-side connections LG1, LG2, LG3 of the series connection of the electronic switch SI, S2, S3 and the mechanical phase contact Kl, K2, K3. Specifically between the mains-side connections LG1, LG2, LG3 and the electronic switches SI, S2, S3. The current sensor units Sil, SI2, SI3 can also be arranged differently. For example, between the electronic switch SI, S2, S3 and the mechanical phase contact Kl, K2, K3. The first, second and third electronic switches can be switched to a high-resistance or low-resistance state independently of one another. This means that the first, second and third electronic switches are switched to a high-resistance or low-resistance state independently of one another. In particular, to avoid or enable a phase-conductor-dependent current flow.In one embodiment of the invention, the electronic switches can be switched to the high-impedance or low-impedance state independently of one another by means of the control input CI.

[0131] Figure 2 shows a representation according to Figure 1 , with the following differences .

[0132] A mains-side neutral conductor connection NG and a load-side neutral conductor connection NL are provided for a neutral conductor N of the multi-phase low-voltage AC circuit, in the example shown in Figure 2, a three-phase low-voltage AC circuit with a neutral conductor. According to Figure 2, the mains-side neutral conductor connection NG is connected to the load-side neutral conductor connection NL via a neutral conductor contact KN.

[0133] Alternatively, the mains-side neutral conductor connection NG can also be connected directly (i.e. without a switchable contact) to the load-side neutral conductor connection NL.

[0134] In this example, an electronic switch is not provided in the neutral conductor path in the protective switching device housing. This means that the neutral conductor connection between the mains-side neutral conductor terminal NG and the load-side neutral conductor terminal NL is free of electronic switches (electronic switch-free).

[0135] Advantageously, the mechanical neutral conductor contact KN can be switched together with the phase contacts Kl, K2, K3. This means that the mechanical neutral conductor contact KN can be opened or closed together with the phase contacts Kl, K2, K3, as described above for the contacts Kl, K2, K3.

[0136] Specifically, the mechanical isolating contact unit MK can be designed such that the neutral conductor contact KN is closed before the phase contacts Kl, K2, K3 are closed. Similarly, the neutral conductor contact KN can be opened after the phase contacts Kl, K2, K3 are opened.

[0137] Furthermore, a power supply NT is provided, such as a power pack, to supply power to the protective switching device SG, in particular to the control unit SE. In the example, the power supply NT is connected to the phase conductors LI, L2, L3 and (if applicable) to the neutral conductor N. It can also be connected to only some of the conductors (at least two) for the power supply. In the example, the power supply NT is also connected to the control unit SE.

[0138] On the other hand, the control unit SE is combined with the electronic switches SI, S2, S3 and the current sensor units Sil, SI2, SI3, as shown in Figure 2.

[0139] Furthermore, a voltage sensor unit is provided between each phase conductor and the neutral conductor. A first voltage sensor unit SUI is provided between the first phase conductor LI and the neutral conductor N, a second voltage sensor unit SU2 is provided between the second phase conductor L2 and the neutral conductor N, and a third voltage sensor unit SU3 is provided between the third phase conductor L3 and the neutral conductor N. These units are used to determine the voltage level between the respective phase and neutral conductors, in particular to determine the instantaneous voltage values. The voltage sensor units SUI, SU2, and SU3 are connected to the control unit SE.

[0140] In the case of a low-impedance switch initiated by the control unit SE, in particular by the control input CI, the electronic switches SI, S2, S3, for example:

[0141] - become low-impedance when initiated by the user (e.g. on the device or by control input) or

[0142] - in the event of a low-resistance event initiated by the protective switching device, especially in the absence of an overcurrent event (i.e. if the first or second current threshold is not exceeded), e.g. if an internal checking function (for internal checking) of the protective switching device initiates a low-resistance event,

[0143] => the electronic switches can advantageously become low-resistance one after the other when the voltage crosses zero.

[0144] In the case of a high-impedance signal initiated by the control unit SE, in particular by the control input CI, the electronic switches SI, S2, S3, for example:

[0145] - become high-impedance when initiated by the user (e.g. on the device or by control input) or

[0146] - in the event of a high-resistance event initiated by the protective switching device, especially in the absence of an overcurrent event (i.e. if the first or second current threshold is not exceeded), e.g. if an internal checking function (for internal checking) of the protective switching device initiates a high-resistance event,

[0147] => advantageously, the electronic switches can become high-resistance one after the other at the respective zero crossing of the voltage (= in the area of ​​the zero crossing).

[0148] Alternatively or in addition to using the voltage, the protective switching device can be designed such that when a STANDBY state or standby state is initiated, in which all electronic switches (SI, S2, S3) are in the high-impedance state (or are intended to reach the high-impedance state), this high-impedance state is established when the current of the respective conductor passes through zero through the respective electronic switch (in particular when a current flows in the phase conductors). The voltage sensor units SUI, SU2, SU3 are, as already mentioned, connected to the control unit SE, which is further connected to the current sensor units S11, SI2, SI3, the mechanical phase contacts K1, K2, K3 (or mechanical isolating contact unit MK), the electronic switches SI, S2, S3 and the control input CI.The protective switching device SG can also advantageously be designed such that, upon exceeding at least a first current threshold (specifically, the instantaneous current value) in a conductor, the corresponding electronic switch initiates a current flow prevention in the respective conductor. At the next or subsequent zero crossing of the voltage (in the region of the zero crossing), the electronic switch returns to low resistance to allow current flow.

[0149] This can be done several times until a certain number of repetitions is exceeded. Then: a) all electronic switches become high-impedance, or (and) b) the contacts open (galvanic isolation).

[0150] Any combinations (intermediate combinations) from the representations of the exemplary protective switching devices according to Figures 1 and 2 are possible (e.g. power supply NT from Figure 2 in Figure 1, etc.).

[0151] Figure 3 shows a representation similar to Figure 2, with the difference that measuring resistors R12, R13, and R23 are provided between the phase conductors within the protective switching device. For this purpose, in one embodiment, a first measuring resistor (or measuring impedance) R12 is provided between the first phase conductor LI and the second phase conductor L2, a second measuring resistor (or measuring impedance) R23 is provided between the second phase conductor L2 and the third phase conductor L3, and a third measuring resistor (or measuring impedance) R13 is provided between the first phase conductor LI and the third phase conductor L3.

[0152] In this way, in particular when there is no neutral conductor (3-pole protective switching device), the switching behavior of the electronic switches SI, S2, S3 can be checked using the measuring resistors (which can also be designed as measuring impedances, e.g. as resistance / capacitance and / or inductance combinations), for example by briefly switching on (ps, ms or small seconds range) the electronic switches with the contacts open, whereby a measuring current corresponding to the measuring resistance (the measuring impedance) is provided and can be checked (at the respective instantaneous values ​​of the voltage).

[0153] In the case of a 4-pole device, e.g. for a three-phase alternating current circuit with neutral conductor, the measuring resistors can (alternatively) also be provided between the phase and neutral conductors.

[0154] The (optional) differential current sensor unit ZCT is not provided in this example (but could also be provided).

[0155] High-resistance refers to a state in which only a negligible current flows. In particular, high-resistance refers to resistance values ​​greater than 1 kiloohm, preferably greater than 10 kiloohms, 100 kiloohms, 1 megaohm, 10 megaohms, 100 megaohms, 1 gigaohm, or greater.

[0156] Low-resistance refers to a condition in which the current value specified on the protective device could flow. Specifically, low-resistance refers to resistance values ​​less than 10 ohms, preferably less than 1 ohm, 100 milliohms, 10 milliohms, 1 milliohm, or less.

[0157] The electronic switches SI, S2, S3, or the electronic interrupt unit EU can contain semiconductor components such as bipolar transistors, field-effect transistors (FETs), isolated-gate bipolar transistors (IGBTs), metal-oxide-layer field-effect transistors (MOSFETs), or other (self-commutated) power semiconductors. IGBTs and MOSFETs in particular are particularly well-suited for electronic switches (as semiconductor-based switching elements) due to their low forward resistance, high junction resistance, and good switching behavior.

[0158] The protective switching device according to the invention thus contains electronic and mechanical components. The sensible arrangement of all required components for safe operation is one aspect. Furthermore, several switching combinations are possible by combining the electronic switch and mechanical contacts.

[0159] In this example, the protective switching device has three mains-side and three load-side connections, or four mains-side and four load-side connections. The device contains a 3- or 4-pole mechanical isolating contact unit (isolating contact system). The contacts are mechanically coupled and can only be opened or closed together.

[0160] An electronic switch is located in series with the mechanical contact in the phase conductors. Unlike the mechanical contacts, these switches are switched on or off independently of each other (in a simple version, switching of all electronic switches is initiated by the control input—the electronic switches can even switch at zero crossings of the voltage or current). Furthermore, a current sensor unit is provided in the phase conductors (not in the neutral conductor N).

[0161] Mechanical contacts or mechanical isolating contact unit MK particularly refers to a (standard-compliant) isolating function implemented by the isolating contact unit MK. The isolating function includes the following points: - minimum air gap according to the standard (minimum distance between the contacts), - contact position indicator of the contacts of the mechanical isolating contact unit, - actuation / interruption of the contacts of the mechanical isolating contact unit (by the control unit) is always possible (no (permanent) blocking of the contacts in the closed state by the handle is possible). The minimum air gap between the contacts of the isolating contact unit is essentially voltage-dependent. Other parameters are the degree of contamination, the type of field (homogeneous, inhomogeneous), and the air pressure or altitude above sea level.

[0162] There are corresponding regulations and standards for these minimum clearances and creepage distances. These regulations specify, for example, the minimum clearance for an inhomogeneous and a homogeneous (ideal) electric field in air for impulse voltage resistance, depending on the degree of pollution. The impulse voltage resistance is the resistance when a corresponding impulse voltage is applied. Only if this minimum length (minimum distance) is present does the isolating contact unit or protective switching device have an isolating function (isolating property).

[0163] For the purposes of the invention, the DIN EN 60947 and IEC 60947 series of standards are relevant for the isolating function and its properties, to which reference is made here.

[0164] The isolating contact unit is advantageously characterized by a minimum clearance between the open isolating contacts in the open position (open position, open contacts) depending on the rated impulse withstand voltage and the degree of pollution. The minimum clearance is, in particular, between (at least) 0.01 mm and 14 mm. In particular, the minimum clearance is advantageously between 0.01 mm at 0.33 kV and 14 mm at 12 kV, in particular for pollution degree 1 and in particular for inhomogeneous fields.

[0165] Advantageously, the minimum air gap can have the following values: E DIN EN 60947-1 (VDE 0660-100): 2018-06

[0166] Table 13 - Minimum clearances

[0167] The pollution levels and field types correspond to those defined in the standards. This advantageously allows for a standard-compliant protective switching device dimensioned according to the rated impulse withstand voltage.

[0168] In particular, the term mechanical isolating contact unit does not refer to a relay contact.

[0169] Figure 4 shows a representation according to Figure 1, 2 or 3, with the difference that individual units are not shown and that the first, second and third measuring resistors R12, R13, R23 are not provided between the phase conductors (Figure 3). Instead, a measuring resistor is provided between each phase conductor and the neutral conductor. For this purpose, a fourth measuring resistor RA (or measuring impedance) is provided between the first phase conductor LI and the neutral conductor N, a fifth measuring resistor RB (or measuring impedance) is provided between the second phase conductor L2 and the neutral conductor N, and a sixth measuring resistor RC (or measuring impedance) is provided between the third phase conductor L3 and the neutral conductor N.

[0170] The switching behavior of the electronic switches SI, S2, S3 can be checked using the fourth, fifth and sixth measuring resistors RI, R2, R3 (which can also be designed as measuring impedances, i.e., as resistance / capacitance and / or inductance combinations), for example by briefly switching on (ps, ms or less than a second range) the electronic switches with open contacts, whereby a measuring current corresponding to the measuring resistance (the measuring impedance) is provided and verifiable (at the respective instantaneous voltage values). This can be done by briefly switching on an electronic switch in order to generate a measuring current across the respective measuring resistor between the phase and neutral conductors. Alternatively or additionally, this can also be done by briefly switching on two electronic switches in order to generate a measuring current across two phase conductors (two measuring resistors).

[0171] Furthermore, further or other units are shown in Figure 4. A (in particular wireless) communication unit COM can be provided, which is connected to the control unit SE or is a part thereof. Furthermore, a display unit AE can be provided. The display unit AE can be designed as a combined display and input unit. The display unit AE (display and input unit) can be connected to the control unit SE or be a part thereof. The display unit AE has visible display means on the protective switching device, in particular for displaying the high-resistance or low-resistance state of the electronic switches or an overall state of the electronic switches.

[0172] According to Figure 4, the control unit SE can have a microcontroller MP (microcontroller unit). The microcontroller can have various functions or routines / procedures, such as

[0173] - a switching logic function SF,

[0174] - an internal protection function IPF, for the internal checking and reporting of the fault-free state of the protective switching device,

[0175] - an external protection function CPF, which monitors the multi-phase low-voltage alternating current circuit and reports, for example, an overcurrent event, short circuit, etc. in the low-voltage circuit,

[0176] - a control signal configuration unit CSC, with which it can be configured, for example, whether the state of the electronic switches (high / low resistance) is changed or (also) the mechanical (phase) contacts are opened by an opening signal TRIP.

[0177] The units and functions mentioned are discussed in more detail below.

[0178] 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 (ON state or On state) and

[0179] - when a current is detected which exceeds a first current value, in particular when the first current value is exceeded for a first time limit, the electronic interruption unit EU becomes high-resistance and the mechanical isolating contact unit MK remains closed, or / and

[0180] - (or / and) in the case of a determined current which exceeds a higher second current value, in particular for a second time limit, the electronic interruption unit EU becomes high-resistance and the mechanical isolating contact unit MK is opened, or / and

[0181] - if the current detected exceeds an even higher third current value, the electronic interruption unit becomes high-resistance and the mechanical isolating contact unit MK is opened.

[0182] The invention is described in more detail below, partially in different terms. In new types of electronic protective switching devices, contacts (of a mechanical isolating contact unit) are used in combination with electronic switches / semiconductor-based switching elements (of an electronic interruption unit). The controllability of these switching elements via a (galvanically isolated) control input CI is a new way of expanding the functions of the protective switching device. At the same time, the invention ensures that the controllability of the switching elements / electronic switches does not impair the safety-relevant protective functions of the protective switching device.

[0183] The control unit SE can switch the electronic switches to a high-impedance or low-impedance state, i.e. switch them on and off, as well as open the contacts (the contact) of the mechanical isolating contact unit.

[0184] Furthermore, a handle (for opening and closing the isolating contact unit), a current measurement, preferably a voltage measurement, and a power supply are provided. The protective switching device can perform various external protection functions (CPF), such as short-circuit protection, overcurrent protection (overload protection), differential fault current protection, fire protection, overvoltage protection, and undervoltage protection. It can also perform various internal protection functions (IFF), such as overtemperature protection.

[0185] Overload protection, for example, is the exceedance of the first current and / or current-time limit values. Short-circuit protection, for example, is the exceedance of the fourth (higher) current and / or current-time limit values. Differential fault current protection, for example, is the exceedance of differential current limits (e.g., 30 mA). Fire protection, for example, is the detection of serial arc faults in low-voltage circuits. The same applies to overvoltage protection, undervoltage protection, and overtemperature protection.

[0186] According to the invention, a control input CI is added, in particular a galvanically isolated one. The switching state of the electronic switches SI, S2, S3 can be controlled via this control input CI. Since the electronic switches are required in particular for carrying out external protective functions CPF, the control unit SE only forwards a signal from the control input CI to make the electronic switches low-impedance (synonym: electronic interruption unit EU) to the electronic switches if there is no error from the stored external or internal protective functions CPF, IPF (no error has been detected), i.e. an enable condition exists. In particular, if an error is detected, i.e. if at least one electronic switch is in the high-impedance state, the control input cannot change this state (i.e. cannot switch to low-impedance).

[0187] This means that the electronic interruption unit EU can only be switched to the low-resistance state via the CI control input if an enabling condition is present. In particular, if the electronic switches are in a high-resistance state due to an external or internal protective function (CPF, IPF) of the protective switching device, they cannot be switched to the low-resistance state via the control input.

[0188] A detected internal fault in the protective switching device refers in particular to a protective switching device fault, such as a defective current sensor unit, defective electronic switches, or overtemperature. Furthermore, this can also be the case with external faults, such as overvoltage or undervoltage (the effective value of the voltage is exceeded or undershot for a certain period of time). Furthermore, this can affect the external protective functions CPF, so that after the current and / or current-time limit values ​​are exceeded and the current flow in the low-voltage circuit is prevented, an immediate "forced" low-resistance switching via the CI control input is not possible or not possible immediately.

[0189] The same applies to other internal device functions / protective device-side testing functions, e.g., for device diagnostics or inrush handling. This means that protective device-side testing functions that a) switch an electronic switch in a high-resistance state to the low-resistance state for a first period of time or (and) b) switch an electronic switch in a low-resistance state to the high-resistance state for a second period of time cannot be influenced by the control input.

[0190] These short switching operations can be used, for example, to test the electronic switches or to check the functionality of the current sensor unit.

[0191] These short switching operations are prioritized by the control unit SE or the switching logic function SF, so that an (external) control signal ESS at the control input CI cannot prevent these short switching operations.

[0192] The controllability of the electronic switches or the (if applicable) electronic interruption unit EU (its switching elements) is therefore only possible via the control input CI if the protective switching device is in a fault-free state and / or no fault has been detected, particularly at the load-side connection / connections (at the load outgoing circuit) Load (a release condition exists). This task is carried out by the switching logic function SF. The control input CI cannot therefore directly control the electronic switches (or the electronic interruption unit), but can only send a signal ESS I to the switching logic function SF to switch the electronic interruption unit on or off. The switching logic function SF ensures that the external and internal protection functions CPF, IFF can always have priority over the electronic switches (electronic interruption unit).

[0193] This applies not only to the external and internal protective functions CPF, IPF of the protective switching device, but also to the (partially already mentioned) testing functions of the protective switching device, which in particular check the switchability of the electronic switches by, for example, switching them on or off for the (short) first or second time period. Figure 5 shows the basic structure of a galvanically isolated control input CI in conjunction with an external control unit ESE.

[0194] Figure 5 shows a control input CI, which is accessible on the housing side GEH. It has several connection terminals, in the example two connection terminals AKI, AK2, whereby the two connection terminals AKI, AK2 are connected internally to at least one optocoupler OPK. In the example, the optocoupler OPK is connected on the one hand to a resistor RI, whereby the resistor RI is also connected to a voltage of 3.3V (iB positive connection to an internal voltage of 3.3 volts). The connection between resistor RI and optocoupler OPK is accessible {OV; 3.3V} {0.1} and in the example supplies an internal control signal ESSI equivalent to the external control signal ESS (and galvanically isolated) for further processing in the protective switch device. The other side connection of the optocoupler OPK is connected to the other connection of the voltage 0V (iB ground connection).

[0195] The two connection terminals AKI and AK2 are connected to a two-wire cable on the outside of the housing, comprising a first conductor LT1 and a second conductor LT2. The two-wire cable is also connected to an external control unit ESE.

[0196] The external control unit ESE optionally provides a 24V voltage signal, which is used to control the optocoupler OPK via the control input CI, to make the electronic interruption unit (required) high or low impedance.

[0197] This means that an optocoupler (OPK) with appropriate galvanic isolation is provided. An external (remote) control unit (ESE) sends a voltage to transmit a control signal (ESS).

[0198] Instead of the optocoupler, a relay or other element for galvanic isolation can also be provided or used. Such as elements based on capacitive or inductive galvanic isolation. Similarly, three or four (or more) connection terminals can be provided to switch each electronic switch individually via corresponding connection terminals. A common connection terminal can be provided, and the first, second, or third electronic switch is then switched via the second, third, and fourth connection terminals, respectively.

[0199] Figure 6 shows the function grouping for the microcontroller MP again. The microcontroller MP has a connection to the control input CI, which receives a signal from the control input SCI, ESS I. This signal is then fed to a control signal configuration unit CSC. Optionally, it can be configured here, for example, that the control input CI opens the mechanical contacts (mechanical isolating contact unit MK) using an opening signal TRIP (open contact / contacts). The signal from the control input is then fed to the switching logic function SF. The switching logic function is further connected to the protection functions, in the example with the internal protection function IPF, for the internal checking and reporting of the fault-free status of the protective switching device, and the external protection function CPF, which monitors the multi-phase low-voltage AC circuit and reports an overcurrent event, short circuit, etc. in the low-voltage circuit.

[0200] If the protective switching device does not have an internal fault, which is reported by the internal protection function IPF, and there is no external fault in the low-voltage circuit to be protected, which is reported by the external protection function CPF, both messages are sent to the switching logic function SF, an enable condition exists and the electronic switches (electronic interruption unit) can be switched to a low-resistance or high-resistance state via the control input CI (connection of the switching logic function SF with the electronic interruption unit EU (arrow pointing there). The switching logic function SF ensures in the protective switching device that the protection functions IFF, CPF, which rely on the controllability of the electronic switches (electronic interruption unit EU), can always switch them safely when required.

[0201] If an external protective function (CPF) is activated, the electronic breaker(s) cannot be controlled via the control input. If no protective state is active (release condition), controllability via the control input is re-enabled for the electronic interruption unit.

[0202] The same principle applies to internal device functions / circuit-switch-side check functions or internal protection functions (IPF). These internal protection functions (IPF) also access the electronic interruption unit. Likewise, internal device functions / circuit-switch-side check functions that only perform a brief switching action, e.g., for a device diagnostic function, primarily access the electronic switch(es). If this function is being executed, control via the control input is not possible for that moment.

[0203] Phases can be switched off (high impedance) briefly, for example for testing purposes.

[0204] The control signal configuration unit CSC can be used to configure what is / should be done with the (digital) control signal.

[0205] For example, the electronic switches (electronic interruption unit EU) can be controlled, or the mechanical contacts (mechanical isolating contact unit) or both.

[0206] This can be done by different levels of the external control signal ESS, time offsets or sequences.

[0207] Examples of parameterization and configuration are given below.

[0208] 1 . ) Simple on / off switching Electronic switches are low-impedance when the external control signal ESS is 1 and high-impedance when the external control signal ESS is 0.

[0209] 2.) Simple on / off switching (inverted)

[0210] Electronic switches are high-impedance when the external control signal ESS is 1 and low-impedance when the external control signal ESS is 0.

[0211] [1 or 2 - general: when a first voltage level is applied, the high-impedance state is initiated, or when a second voltage level is applied, the low-impedance state is initiated]

[0212] 3.) Impulse switching

[0213] Electronic switches change state upon a rising (or falling) signal edge at the control input. This means that the state change of the electronic switches is initiated by a third voltage level present for an initial period of time.

[0214] 4.) Impulse switching with timer

[0215] Electronic switches switch to the on state upon a rising (or falling) signal edge at the control input. The electronic switches automatically switch to the high-impedance state after a (configurable) time period. This means that when a third voltage level is applied for a second period of time, the electronic switches switch to the low-impedance state, and after a third period of time, which can be configured in particular, the electronic switches switch to the high-impedance state.

[0216] 5.) Time-delayed on

[0217] Electronic switches switch as in point 1 or 2, but with an adjustable switch-on delay.

[0218] 6.) Time-delayed off

[0219] Electronic switches switch as in point 1 or 2, but with an adjustable switch-off delay.

[0220] Further parameterization options are:

[0221] 7.) Only open the mechanical contacts. The isolating contact is opened, for example, upon a change in the control signal's edge (or a signal sequence). This is schematically illustrated in Figure 7. Figure 7 shows a parameter configuration in which the external protection function can control three states.

[0222] Al = mechanical contact (s) open, electronic switch high resistance (OFF state or off state)

[0223] S1 = mechanical contact(s) closed, electronic switch high resistance (STANDBY state or standby state)

[0224] El = mechanical contact (s) closed, electronic switch low resistance (ON state or On state)

[0225] The protective switching device is configured such that the contacts are opened via the control input CI. This means that the external / internal control signal ESS / ESSI causes the state Al.

[0226] Figure 8 shows a representation according to Figure 7, with the difference that the external / internal control signal ESS / ESSI causes a simple on / off switching, i.e. low-impedance / high-impedance state of the electronic switches, by means of the switching logic function SF, whereby a high-impedance state occurs when a "positive", logical one control signal ESS / ESSI is present, which is indicated by the state 1 in Figure 8, and when the control signal ESS / ESSI is not present, i.e. logical zero, a low-impedance state is to be initiated, which is indicated by the state 0 in Figure 8.

[0227] Figure 9 shows a representation according to Figure 8, with the difference that it is indicated that the protective switching device is designed or configured in such a way that the electronic switches can be switched between high-impedance / low-impedance states by the control signal ESS / ESSI, for example by a logical zero or one state, alternatively by a first sequence, i.e. a sequence of zero / one states. On the other hand, however, the contacts can also be opened, for example by a second sequence SEQB. In the example, the switching of the mechanical contacts is detected by the control signal configuration unit CSC. This means that the electronic switches can be switched between high-impedance / low-impedance via the control input CI. At the same time, the contacts (of the mechanical isolating contact unit) can be opened via a (switching) sequence stored in the protective switching device.

[0228] Figure 10 shows a representation according to Figures 7 to 9, with the difference that it is indicated that the protective switching device is designed in such a way that an acknowledgement of a fault condition takes place by the control signal ESS / ESS I.

[0229] This means that if the protective switching device is in state S1 due to the current and / or current-time limit values ​​being exceeded, this state can be acknowledged and reset via the CI control input. This allows the protective switching device to be switched from state S1 to state El after a fault (once the fault has cleared). This can be done remotely; the device does not have to be switched to state El on-site.

[0230] This means that the protective switching device SG can be designed in such a way that an acknowledgment of a fault-related high-impedance state of the electronic interruption unit, in particular that the fault-related high-impedance state was initiated by the current and / or current time limit values ​​in the low-voltage circuit being exceeded, takes place by means of the control input CI, so that the electronic switches can be switched to the low-impedance state if there is subsequently no fault or switch / change to the low-impedance state, in particular that it is configurable whether by means of the control input a) the electronic switches can be switched to a high-impedance or low-impedance state or b) an acknowledgment of a fault-related high-impedance state takes place.

[0231] Furthermore, the protective switching device can be designed such that the control input CI: a) initiates the high-impedance state when a first voltage level is applied or the low-impedance state when a second voltage level is applied or b) the state changes due to a third voltage level being applied briefly (e.g. less than 1 second). More specifically, the state is changed to the low-impedance state by a third voltage level being applied briefly (e.g. less than 1 second) and the state is changed back to the high-impedance state by a subsequent third voltage level.

[0232] The display unit has, for example, visible display means on the protective switching device for displaying (representing) the high-resistance or low-resistance state of the electronic switches, for example by means of an LED display.

[0233] The display of the contact position of the mechanical isolating contact unit is realized by the handle; this display by the handle does not show the switching state of the electronic interruption unit.

[0234] In particular, the switching state of the electronic switches can be advantageously displayed when the switching state has been changed / switched on or off via the control input CI.

[0235] Although the invention has been illustrated and described in detail by the embodiment, the invention is not limited by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of the invention.

Claims

Patent claims 1. Protective switching device (SG) for protecting an electrical multi-phase low voltage alternating current circuit comprising: - a housing (GEH) with mains-side phase connections (LG1, LG2, LG3) and load-side phase connections (LL1, LL2, LL3) for phase conductors (LI, L2, L3) of the low-voltage alternating current circuit, - Series circuits (SSI, SS2, SS3) of a mechanical phase contact (Kl, K2, K3) and an electronic switch (SI, S2, S3), whereby each series circuit (SSI, SS2, SS3) electrically connects one of the mains-side phase connections (LG1, LG2, LG3) with one of the load-side phase connections (LL1, LL2, LL3), - that the mechanical phase contacts (Kl, K2, K3) can be switched together to open in order to avoid a current flow or together to close in order to avoid a current flow, - that the electronic switches (SI, S2, S3) can be switched by means of semiconductor-based switching elements into a high-resistance state of the switching elements to prevent a current flow or into a low-resistance state of the switching elements to allow current flow, - that for each series circuit (SSI, SS2, SS3) a current sensor unit (Sil, SI2, SI3) is provided to determine the current level of the respective phase conductor (LI, L2, L3), - that a control unit (SE) is provided which is connected to the current sensor units (S11, SI2, SI3), the mechanical phase contacts (K1, K2, K3) and the electronic switches (SI, S2, S3), that the protective switching device is designed in such a way that if at least one first current threshold value and / or current time limit values ​​in a phase conductor are exceeded, the avoidance of a current flow is initiated, - that a control input (CI) is provided on the protective switching device (SG), - that the protective switching device is designed in such a way that the electronic switches (SI, S2, S3) can be switched to a high-impedance or low-impedance state by means of the control input (CI).

2. Protective switching device (SG) according to claim 1, characterized in that the protective switching device is designed such that by means of the control input (CI) the electronic switches (SI, S2, S3) can be switched independently of one another into a high-resistance or low-resistance state.

3. Protective switching device (SG) according to claim 1 or 2, characterized in that the protective switching device is designed such that when at least a first current threshold value in a phase conductor is exceeded, avoidance of a current flow in the phase conductor in question, in particular for a first period of time, is initiated by the electronic switch in question.

4. Protective switching device (SG) according to claim 1, 2 or 3, characterized in that the mechanical phase contacts (Kl, K2, K3) are assigned to the load-side phase connections and the electronic switches (SI, S2, S3) are assigned to the mains-side phase connections, in particular that the mechanical phase contacts (Kl, K2, K3) can be operated by a mechanical handle in order to switch an opening of the phase contacts or a closing of the phase contacts, in particular that the mechanical phase contacts (Kl, K2, K3) are part of a mechanical isolating contact unit (MK) which switches the phase contacts together.

5. Protective switching device (SG) according to one of the preceding claims, characterized in that the control input (CI) has a, in particular safe, has galvanic isolation, especially between control input and phase conductors.

6. Protective switching device (SG) according to one of the preceding claims, characterized in that by means of the control input (CI) the electronic switches can only be switched to a low-resistance state if a release condition exists, in particular that in the case of a high-resistance state of at least one electronic switch caused by an external protective function (CPF) of the protective switching device, the electronic switch(es) cannot be switched to the low-resistance state by the control input.

7. Protective switching device (SG) according to one of the preceding claims, characterized in that testing functions on the protective switching device side which a) switch (at least) one electronic switch in the high-resistance state to the low-resistance state for a first period of time or b) switch (at least) one electronic switch in the low-resistance state to the high-resistance state for a second period of time cannot be influenced by the control input (CI).

8. Protective switching device (SG) according to one of the preceding claims, characterized in that the phase contacts (Kl, K2, K3) can be opened by means of the control input (CI), in particular it is configurable whether by means of the control input a) the electronic switches (S1, S2, S3) can be switched to a high-resistance or low-resistance state or b) the phase contacts (Kl, K2, K3) can be opened.

9. Protective switching device (SG) according to one of the preceding claims, characterized in that the control input (CI) is accessible on the housing side, in particular has a plurality of connection terminals (AKI, AK2), in particular two, three or four connection terminals, wherein the connection terminals (AKI, AK2) are connected internally in the protective switching device to at least one element for galvanic isolation, in particular optocoupler (OPK).

10. Protective switching device (SG) according to one of the preceding claims, characterized in that a display unit (AE) connected to the control unit (SE) is provided, which has display means visible on the protective switching device for displaying the high-resistance or low-resistance state of the electronic switches (SI, S2, S3).

11. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device is designed such that in a STANDBY state initiated by the control input (CI), in which all electronic switches (S1, S2, S3) are to be in the high-impedance state, this high-impedance state is established in the region of the current zero crossing of the current of the respective electronic switch.

12. Protective switching device (SG) according to one of the preceding claims, characterized in that a mains-side neutral conductor connection (NG) and a load-side neutral conductor connection (NL) are provided on the housing (GEH) for a neutral conductor (N) of the multi-phase low-voltage alternating current circuit.

13. Protective switching device (SG) according to claim 12, characterized in that the mains-side neutral conductor connection (NG) is connected to the load-side neutral conductor connection (NL) via a mechanical neutral conductor contact (KN).

14. Protective switching device (SG) according to claim 13, characterized in that the mechanical neutral conductor contact (KN) can be opened or closed together with the phase contacts (Kl, K2, K3), in particular that the neutral conductor contact (KN) is closed before the phase contacts (Kl, K2, K3) are closed or that the neutral conductor contact (KN) is opened after the phase contacts (Kl, K2, K3) are opened.

15. Protective switching device (SG) according to one of the preceding claims 12 to 14, characterized in that between each phase conductor and the neutral conductor there is provided a voltage sensor unit (SUI, SU2, SU3) connected to a / the control unit (SE), for determining the level of the voltage between the respective phase and neutral conductor, in particular the instantaneous voltage values, that when the control unit (SE), in particular the control input (CI), initiates a low-resistance switching of the electronic switches (SI, S2, S3), these, in particular one after the other, become low-resistance in the region of the respective zero crossing of the voltage of the respective phase conductor.

16. Protective switching device (SG) according to claim 15, characterized in that when the electronic switches (SI, S2, S3) become high-impedance initiated by the control unit (SE), in particular the control input (CI), these become high-impedance, in particular one after the other, in the region of the respective zero crossing of the voltage of the respective phase conductor.

17. Protective switching device (SG) according to one of claims 15 or 16, characterized in that the control unit (SE) is connected to the current sensor units (S11, SI2, SI3), the voltage sensor units (SU1, SU2, SU3), the mechanical contacts and the electronic switches (SI, S2, S3), that the protective switching device (SG) is designed in such a way that when at least one current threshold value in a conductor is exceeded, avoidance of a current flow in the conductor in question is initiated by the electronic switch in question, that at the next or next but one zero crossing of the voltage the electronic switch becomes low-resistance again in order to enable a current flow.

18. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device is designed such that the control input (CI): a) initiates the high-impedance state when a first voltage level is applied or the low-impedance state when a second voltage level is applied or b) initiates the state change between high-impedance or low-impedance state or low-impedance or high-impedance state by a third voltage level applied for a first time period or c) initiates a change of the electronic switches to the low-impedance state by a third voltage level applied for a second time period and after a third time period, which is in particular adjustable, the electronic switches change to the high-impedance state.

19. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device (SG) is designed such that by means of the control input (CI) an acknowledgment of a fault-related high-resistance state of at least one electronic switch takes place, in particular that the fault-related high-resistance state was initiated by the current and / or current time limit values ​​in the low-voltage circuit being exceeded, so that the electronic switches can be switched to the low-resistance state if there is subsequently no fault or switch automatically to the low-resistance state, in particular that it is configurable whether by means of the control input a) the electronic switches can be switched to a high-resistance or low-resistance state or b) an acknowledgment of a fault-related high-resistance state takes place.

20. Method for a protective switching device (SG) for protecting a multi-phase low voltage alternating current electrical circuit with: - a housing (GEH) with mains-side phase connections (LG1, LG2, LG3) and load-side phase connections (LL1, LL2, LL3) for phase conductors (LI, L2, L3) of the low-voltage alternating current circuit, - Series circuits (SSI, SS2, SS3) of a mechanical phase contact (Kl, K2, K3) and an electronic switch (SI, S2, S3), whereby each series circuit (SSI, SS2, SS3) electrically connects one of the mains-side phase connections (LG1, LG2, LG3) with one of the load-side phase connections (LL1, LL2, LL3), - that the mechanical phase contacts (Kl, K2, K3) are switched together to open in order to avoid a current flow or together to close in order to avoid a current flow, - that the electronic switches (SI, S2, S3) are switched by means of semiconductor-based switching elements into a high-resistance state of the switching elements to prevent a current flow or a low-resistance state of the switching elements to allow current flow, - that in each series circuit (SSI, SS2, SS3) the current level of the respective phase conductor (LI, L2, L3) is determined, - that if at least one first current threshold or current time limit is exceeded in a phase conductor, the avoidance of a current flow is initiated, - that the electronic switches (SI, S2, S3) can be switched to a high-impedance or low-impedance state by means of a control input (CI).

21. Method for a protective switching device (SG) according to claim 20, characterized in that by means of the control input (CI) the electronic switches (SI, S2, S3) are only switched to a low-impedance state if a release condition exists, in particular that in the case of a high-impedance state of at least one electronic switch caused by a protective function (CPF) of the protective switching device, the electronic switches (SI, S2, S3) cannot be switched to the low-impedance state by the control input.

22. Protective switching device (SG) according to claim 20 or 21, characterized in that testing functions on the protective switching device side which a) switch an electronic switch in the high-resistance state to the low-resistance state for a first period of time or b) switch an electronic switch in the low-resistance state to the high-resistance state for a second period of time are not influenced by the control input (CI).

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