Hybrid circuit breaker device, hybrid protection device and method

Abstract

The invention relates to a hybrid circuit breaker device (30), in particular a DC hybrid circuit breaker device, having at least one mechanical interrupter switch (10) and having at least one semiconductor circuit breaker (12), in particular a semiconductor relay, connected electrically in parallel to the mechanical interrupter switch (10). According to the invention, the mechanical interrupter switch (10) has a tripping element (14), in particular a magnetic field-sensitive tripping element, which is at least partially formed from a magnetic shape memory alloy (16).

Description

[0001] Hybrid circuit breaker device, hybrid contactor and method

[0002] State of the art

[0003] The invention relates to a hybrid circuit breaker device according to the preamble of claim 1, a hybrid contactor according to claim 15 and a method according to claim 16.

[0004] In particular, a contribution to the 30th International Conference on Electrical Contacts by the author Wolfgang Hauer entitled “New Switching Technology for DC Grids” already discloses a hybrid circuit breaker device with at least one mechanical interruption switch and with at least one semiconductor circuit breaker electrically connected in parallel to the mechanical interruption switch.

[0005] The object of the invention is, in particular, to provide a generic device with advantageous properties regarding protection against overcurrent. This object is achieved according to the invention by the features of patent claims 1, 15, and 16, while advantageous embodiments and further developments of the invention can be found in the subclaims.

[0006] Advantages of the invention

[0007] The invention is based on a hybrid circuit breaker device, in particular a DC hybrid circuit breaker device, with at least one mechanical interrupter and with at least one semiconductor circuit breaker, in particular a semiconductor relay, electrically connected in parallel with the mechanical interrupter. It is proposed that the mechanical interrupter has a tripping element, in particular a magnetic field-sensitive element, which is formed at least partially from a magnetic shape memory alloy (also known as MSM material = Magnetic Shape Memory). This advantageously improves protection against overcurrent, in particular by achieving a particularly high response speed / tripping speed of the mechanical interrupter.This advantageously allows for fast-reacting, thus safe, and cost-effective overcurrent protection, which is particularly suitable for DC networks where, in the event of a fault, very high current rise rates (up to 100 A / ps) with very high currents (up to 10 kA) can occur, especially compared to AC networks. This high speed can be achieved with simultaneously low electrical losses during nominal operation, such as those that can occur with a contactor based solely on solid-state relays.

[0008] A "hybrid circuit breaker device" is understood to mean, in particular, a functional component, in particular a structural and / or functional component, of a hybrid contactor. A "hybrid contactor" is understood to mean, in particular, a hybrid circuit breaker intended to effect emergency shutdown of a current flow within a circuit via an interaction of mechanical and semiconductor-based switching components. In particular, the hybrid circuit breaker device is intended for use in and / or installation in a hybrid contactor. The hybrid contactor is advantageously intended to protect the circuit, connected equipment, and / or its cables from overload and / or overcurrent and / or short-circuit current. "Intended" is understood to mean, in particular, specially programmed, designed, and / or equipped.The fact that an object is intended for a specific function should be understood in particular to mean that the object fulfills and / or executes this specific function in at least one application and / or operating state. A DC hybrid circuit breaker device is provided for interrupting a direct current circuit. In particular, the mechanical interrupter is provided to generate an interruption of the circuit at least by a mechanical movement of a component, preferably by a mechanical opening of an electrical contact of the circuit. In particular, the semiconductor circuit breaker is provided to generate an interruption of the circuit at least by electrically controlling a semiconductor component.For example, the semiconductor circuit breaker can be designed as an insulated-gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET). In particular, the semiconductor circuit breaker forms a semiconductor interrupt switch, and vice versa.

[0009] In particular, a tripping event in which the circuit is opened by the hybrid circuit breaker device comprises an overcurrent event, in particular a short-circuit event and / or an overload event. In particular, the tripping event, in particular in a short-circuit event, can comprise a magnetic tripping event. In addition, the tripping event, in particular in an overload event, can comprise a thermal tripping event. In this case, a tripping element is provided both for the thermally induced deformation, in particular in an overload event, and for the magnetically induced deformation, in particular in a short-circuit event. Particularly preferably, the deformation comprises at least a change in the length of the tripping element, in particular along its longitudinal axis. Advantageously, the tripping element is provided to generate a movement and / or a force to open the circuit, in particular directly, due to the deformation.Advantageously, the movement to open the circuit is a stroke and / or a change in the longitudinal extent of the trigger element. It is also conceivable that the trigger element is provided to generate the movement and / or the force to open the circuit due to a deformation in a direction angular and / or perpendicular to the longitudinal axis of the trigger element. The longitudinal direction runs in particular at least substantially parallel to a main extension direction of the trigger element, wherein a "main extension direction" of an object is to be understood in particular as a direction that runs parallel to a longest edge of a smallest geometric cuboid that just completely encloses the object. In particular, the trigger element is provided to actuate a switch, for example a toggle switch, which, in the open state, opens electrical contacts of the circuit.In particular, the current in the tripping case is greater than a nominal current, in particular a standard household or standard industrial (DC) nominal current. The tripping unit can be designed for any nominal currents, for example for (DC) nominal currents of 63 A, 100 A, 200 A, etc., but also for significantly larger or significantly smaller nominal currents. In particular, the current in the overload case is greater than the nominal current, preferably for at least a period of time in the range of seconds or minutes. For example, in alternating current circuits, the overload case occurs at currents that are at least in a range above 1.15 times, preferably 1.45 times, the nominal current. It is assumed that similar limit values ​​apply to direct current circuits as well as to alternating current circuits. Furthermore, the current in the short circuit case is in particular greater than the current in the overload case.In particular, in alternating current circuits, a short circuit occurs at currents that are at least five times, preferably ten times, the rated current. It is assumed that, even in the case of a short circuit, similar limits apply to DC circuits as to AC circuits.

[0010] In particular, the triggering element is designed separately from conductor tracks of the circuit to be monitored. Preferably, the triggering element is arranged at least partially, preferably completely, in a close range of a current-carrying conductor section of the circuit to be monitored. In this context, a "close range" is to be understood in particular as an area formed by points that are arranged at a distance from the current-carrying conductor section of at most ten times, preferably at most seven times, more preferably at most five times, and particularly preferably at most three times the line diameter of the current-carrying conductor section. In particular, the points forming the close range are each at a distance of at most 10 mm, preferably at most 5 mm, and particularly preferably at most 3 mm from the conductor section.In particular, the triggering element is arranged relative to the current-carrying conductor section of the circuit to be monitored in such a way that a magnetic field generated at least temporarily by a strong current increase runs through the triggering element. Preferably, the triggering element and the current-carrying conductor section of the circuit to be monitored extend at least substantially parallel to one another, at least in the near field. "Substantially parallel" is understood here to mean, in particular, an alignment of a direction relative to a reference direction, in particular in a plane, wherein the direction deviates from the reference direction by, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°.Preferably, the current-carrying conductor section of the circuit to be monitored is different from a part of an electrical coil, in particular running straight or curved, preferably not wound and not wound multiple times.

[0011] In particular, the current-carrying conductor section of the circuit to be monitored is designed as a single conductor. In particular, the triggering element is provided to react to (strong) magnetic field changes generated by the current-carrying conductor section of the circuit to be monitored, in particular by a change in length. It is also conceivable that the conductor section heats up in the event of triggering, in particular due to a current in the circuit to be monitored exceeding the rated current, whereby any resulting thermal radiation can be absorbed by the triggering element and thereby cause the optional further thermal triggering event. Particularly preferably, the current flowing in the conductor section in the circuit to be monitored in the event of triggering, in particular in the event of a short circuit, generates a triggering magnetic field for the triggering element.In particular, the trigger element can be influenced and / or deformed by means of the conductor section and / or by means of a magnetic field generated by the conductor section, particularly in the event of triggering. The trigger element can be plunger-shaped, elongated, rod-shaped, pin-shaped, and / or cylindrical. In particular, a main deformation axis is the axis of greatest deformation of the trigger element. Preferably, the main deformation direction is arranged at least substantially parallel to the longitudinal axis of the trigger element. Preferably, the trigger element has an at least substantially constant cross-section. Preferably, the trigger element is formed as a single piece.

[0012] The trigger element is advantageously designed as a solid body. However, it is also conceivable for the trigger element, in particular at least in sections, to be designed as a hollow body, for example as a hollow cylinder, and / or as a solid body with recesses and / or cavities or the like. The trigger element is preferably formed at least largely, in particular entirely, from the magnetic shape memory alloy. Particularly preferably, the hybrid switch device has a single trigger element. However, it is also conceivable for the hybrid switch device to have a plurality of trigger elements, in particular identical or differently designed to one another.The fact that an object has an "at least substantially constant cross-section" should be understood in particular to mean that for any first cross-section of the object along at least one direction and any second cross-section of the object along the direction, a minimum surface area of ​​a differential area formed when the cross-sections are placed on top of one another amounts to a maximum of 20%, advantageously a maximum of 10%, and particularly advantageously a maximum of 5% of the surface area of ​​the larger of the two cross-sections. The expression "at least for the most part" should be understood in particular to mean at least 55%, advantageously at least 65%, preferably at least 75%, particularly preferably at least 85%, and particularly advantageously at least 95%, but in particular also completely.

[0013] The magnetic shape memory alloy preferably contains nickel, manganese, and gallium. The magnetic shape memory alloy is particularly preferably a nickel-manganese-gallium alloy. Alternatively, the magnetic shape memory alloy could also be an iron-palladium alloy and / or an iron-palladium-containing alloy. Furthermore, the magnetic shape memory alloy could also be formed as a foam and / or a composite structure and / or as a granulate and / or as a porous material. Particularly in the case of a composite material, it is conceivable that nickel, manganese, and / or gallium components could be embedded in a matrix. Furthermore, the magnetic shape memory alloy could be formed as a single crystal. The trigger element is preferably formed as a single crystal made of the magnetic shape memory alloy.It is also conceivable that the trigger element is composed of several, in particular several, single crystals, for example, two or three or four or five. However, it is also conceivable that the magnetic shape memory alloy is polycrystalline.

[0014] In particular, the mechanical interrupter switch is designed to commutate the current to the semiconductor circuit breaker in the event of an overcurrent as soon as the mechanical interrupter switch begins to open. In particular, a voltage from an arc ignited when the mechanical interrupter switch opens can optionally be used for the commutating action. The commutating current then extinguishes the arc. Preferably, the triggering event is non-destructive and repeatable after all components of the hybrid circuit breaker device have been reset. Contact erosion can advantageously be avoided.

[0015] It is further proposed that the mechanical interrupter has an opening time of less than 400 ps, ​​preferably less than 200 ps, ​​in the event of a trip. This advantageously enables a particularly fast response. Suitability for DC networks can be advantageously achieved. A particularly high level of safety can advantageously be achieved. By accelerating the mechanical opening of the hybrid contactor, the use of smaller semiconductor circuit breakers and / or varistors in the other branches of the hybrid contactor can be advantageously enabled, particularly since a comparatively smaller current overall has to be extinguished by the hybrid contactor. The “opening time” of the mechanical interrupter in this case is to be understood in particular as a time which elapses between the occurrence of a fault current, e.g.a short circuit, up to a partial opening of the mechanical circuit breaker, during which the arc generated during the opening provides sufficient voltage for the electronics of the semiconductor circuit breaker, in particular for commutating the current to the branch of the hybrid circuit breaker device with the semiconductor circuit breaker. In particular, the opening time can also be understood as the time from the occurrence of the fault current (start of the opening movement of the tripping element) until a maximum current value is reached in the branch of the hybrid circuit breaker device with the mechanical circuit breaker (partial opening, during which the resulting arc voltage corresponds to an activation voltage of the semiconductor circuit breaker).In particular, the opening time can also be understood as the time from the occurrence of the fault current until the start of a current flow through the branch of the hybrid circuit breaker device with the semiconductor circuit breaker. In particular, components of a circuit connected in parallel each have at least essentially the same voltage. Therefore, if the voltage in the branch of the hybrid circuit breaker device with the mechanical circuit breaker increases, the voltage at the semiconductor circuit breaker also increases simultaneously, so that above a certain voltage, the semiconductor circuit breaker is "disconnected."

[0016] Furthermore, it is proposed that the trigger element, in particular produced by a (mechanical) surface treatment of the magnetic shape memory alloy, comprise a plurality of coherently movable twin boundaries. This advantageously makes it possible to achieve a high contraction or expansion speed of the trigger element. Advantageously, a particularly high level of safety can be achieved. In particular, each twin boundary of a magnetic shape memory alloy has a maximum movement speed, which depends, among other things, on a specific microstructure of the material and / or a configuration of the twin boundaries. By having a plurality of twin boundaries, the achievable maximum movement speed can thus be advantageously increased, possibly even to the point where the limitation of the movement speed is dominated by an unavoidable mass inertia of the volume of the trigger element to be moved.In particular, additional twin boundaries can be created by a suitable surface treatment of the magnetic shape memory alloy, such as roughening a surface of the magnetic shape memory alloy, shot peening the surface of the magnetic shape memory alloy, or the like.

[0017] If distances between adjacent twin boundaries of the tripping element are less than 300 pm, preferably less than 150 pm and more preferably less than 100 pm, a particularly high / optimal movement speed for the deformation of the tripping element can advantageously be achieved. In particular, the distance between the adjacent twin boundaries is measured in the longitudinal direction of the tripping element. Furthermore, it is proposed that the mechanical interruption switch be designed without a coil. This advantageously makes it possible to reduce the complexity of the hybrid circuit breaker device, in particular of the hybrid contactor, preferably of the mechanical interruption switch. A simple and / or cost-effective design can advantageously be achieved. A particularly compact design of the hybrid circuit breaker device, in particular of the hybrid contactor, can advantageously be achieved.

[0018] If, in addition, the hybrid circuit breaker device has a design that is free of, in particular completely free of, a choke coil, for example one connected upstream of the mechanical interrupter, complexity can advantageously be further reduced, which in particular advantageously allows costs to be reduced. Preferably, the entire hybrid contactor is free of any inductances / coils. Advantageously, the high speed of the mechanical interrupter makes a choke coil for additionally delaying a current rise in the event of a fault superfluous. Advantageously, a particularly compact design of the hybrid circuit breaker device, in particular of the hybrid contactor, can be achieved. A further advantage of the coil-free design, in particular the omission of the choke coil, in addition to the reduced costs and reduced installation space, is a reduction in power loss during nominal operation (even in DC circuits).

[0019] Furthermore, it is proposed that the mechanical interrupter switch be designed to be at least substantially free of magnetic flux-conducting components, apart from the magnetic shape memory alloy of the tripping element. This advantageously minimizes inductive resistance, particularly in the event of a short circuit, thereby advantageously reducing a time constant and / or thermal losses, so that a particularly high reaction speed can be achieved. In particular, the magnetic fields generated by the overcurrent in the event of a fault, particularly in the case of direct current, are already high enough to reliably switch the tripping element. In particular, the tripping element is designed to be free of further magnetic flux-conducting components, apart from the magnetic shape memory alloy.

[0020] In addition, it is proposed that the hybrid circuit breaker device comprise at least one further mechanical interrupter arranged in series at least with the semiconductor circuit breaker, which is designed to trigger with a time delay and / or more slowly than the mechanical interrupter. This advantageously makes it possible to achieve a particularly high level of safety. In particular, the further mechanical interrupter is designed to establish galvanic isolation of the circuit (which cannot be achieved by the semiconductor circuit breaker and / or the varistor alone). In particular, the dynamic requirements of the further mechanical interrupter are significantly lower than those of the mechanical interrupter. In particular, the further mechanical interrupter is also arranged in series with the mechanical interrupter.In particular, the further mechanical interruption switch forms an isolation switch of the hybrid circuit breaker device.

[0021] If the additional mechanical interrupter has a trigger element that is at least partially formed from a magnetic shape memory alloy, a particularly advantageous circuit of the additional mechanical interrupter can be achieved. A simple construction can be achieved.

[0022] If the tripping element of the mechanical circuit breaker also serves as the tripping element of the other mechanical circuit breaker, a particularly high degree of compactness and / or cost-effectiveness of the hybrid circuit breaker device can be advantageously achieved. Furthermore, a compact design can be advantageously achieved.

[0023] It is further proposed that the hybrid circuit breaker device comprise a delay unit designed to temporally delay the action of the triggering element on the further mechanical interrupter switch relative to the action of the triggering element on the mechanical interrupter switch. The delay unit can, for example, be designed as a simple spacing of the further mechanical interrupter switch from the triggering element or from a further component of the hybrid circuit breaker device actuated by the triggering element (e.g., the opening conductor section). In this way, the further mechanical interrupter switch is only actuated when the triggering element has already expanded somewhat and / or when the further component of the hybrid circuit breaker device actuated by the triggering element has already moved somewhat.

[0024] It is also proposed that the magnetic shape memory alloy be designed as a high-temperature magnetic shape memory alloy. This advantageously enables reliable operation of the hybrid circuit breaker device over a wide operating temperature range. Advantageously, a high level of safety can be achieved. Preferably, the magnetic shape memory alloy has at least one, in particular exactly one, first transformation temperature, in particular from at least one martensitic phase to at least one austenitic phase. Particularly preferably, the magnetic shape memory alloy has at least one, in particular exactly one, second transformation temperature, in particular from at least one ferromagnetic phase to at least one paramagnetic phase.Advantageously, the first transformation temperature and the second transformation temperature are selected such that they are at least higher than the temperatures assumed by the triggering element in a normal operating state, particularly when no triggering event occurs. The magnetic high-temperature shape memory alloy is preferably characterized in that the first transformation temperature and / or the second transformation temperature is / are at least 60°C, advantageously at least 70°C, particularly advantageously at least 80°C, and preferably at least 100°C. This advantageously prevents faulty triggering, for example, due to an elevated ambient temperature.

[0025] Furthermore, it is proposed that the mechanical circuit breaker, in particular in addition to the magnetic field-sensitive trigger element, comprise a thermosensitive trigger element. This advantageously provides additional overload protection. Advantageously, a particularly high level of safety can be achieved. In particular, the thermosensitive trigger element is formed from a thermal shape memory alloy, such as nitinol. It is conceivable that the thermal shape memory alloy and the magnetic shape memory alloy are connected to one another to form a common trigger element or are designed as two separate trigger elements, e.g., in the form of two adjacent or interconnected strips.It is also conceivable for the triggering element to be formed from a material that exhibits a magnetic shape memory effect, in particular a high-temperature magnetic shape memory effect, and a thermal shape memory effect. Preferably, the triggering element is designed to be thermally and magnetically shape-changing. A "thermally and / or magnetically shape-changing material" is understood to mean, in particular, a material that can be influenced by a temperature increase, in particular by the supply of thermal energy, and / or by means of a magnetic field, in particular an external one, and is advantageously provided, in at least one operating state, to change at least one material property and / or a shape, at least depending on a temperature of the material and / or at least depending on the magnetic field. However, it is also conceivable for the hybrid circuit breaker device to be designed without a thermosensitive triggering element.

[0026] Furthermore, the hybrid contactor, in particular a DC hybrid contactor, is proposed with the hybrid circuit breaker device and with at least one varistor electrically connected in parallel to the hybrid circuit breaker device. This makes it possible to achieve advantageous properties with regard to speed and / or safety. Advantageously, the hybrid contactor is considerably faster than a mechanical circuit breaker, which, for example, has current interruption times in the millisecond range, and at the same time is considerably cheaper to manufacture and / or maintain than pure semiconductor circuit breakers. “DC” should be understood to mean direct current in particular. In particular, the varistor is electrically connected in parallel to the mechanical interruption switch. In particular, the varistor is electrically connected in parallel to the semiconductor circuit breaker.In particular, the varistor is designed to lead the current to zero after it has been extinguished by the semiconductor circuit breaker (“slowly”).

[0027] Additionally, it is proposed that the hybrid contactor comprise an electromagnet and / or a capacitor electrically connected in parallel with the mechanical circuit breaker and dischargeable by means of a switch, each of which is provided at least to allow a controlled opening of the circuit monitored by the hybrid circuit breaker device. This advantageously allows a controlled shutdown of the hybrid contactor, in particular even under load, preferably without contact erosion. In particular, the electromagnet, preferably the magnetic field generated by the electromagnet, is provided to trigger, preferably deform, the triggering element of the mechanical circuit breaker in a controlled manner.In particular, the capacitor is designed to generate a high discharge current when the switch is closed, by means of which a short circuit can be simulated, so that the triggering element is triggered and the circuit is opened. Furthermore, a method for operating the hybrid circuit breaker device, in particular the DC hybrid circuit breaker device, with at least one mechanical interrupter switch and with at least one semiconductor circuit breaker, in particular a semiconductor relay, electrically connected in parallel with the mechanical interrupter switch, wherein the mechanical interrupter switch is actuated in the event of an overcurrent by a change in the shape of a magnetic shape memory alloy, is proposed.This advantageously improves overcurrent protection, particularly by achieving a particularly high response / tripping speed of the mechanical circuit breaker. This advantageously results in faster, safer, and more cost-effective overcurrent protection.

[0028] The hybrid circuit breaker device according to the invention, the hybrid contactor according to the invention, and the method according to the invention are not intended to be limited to the application and embodiment described above. In particular, the hybrid circuit breaker device according to the invention, the hybrid contactor according to the invention, and the method according to the invention may have a number of individual elements, method steps, components, and units that differs from the number stated herein to fulfill a function described herein.

[0029] Drawings

[0030] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will conveniently consider the features individually and combine them into useful further combinations. They show:

[0031] Fig. 1 is a schematic diagram of a hybrid contactor with a hybrid circuit breaker device,

[0032] Fig. 2a is a schematic representation of a part of the hybrid circuit breaker device in a closed state,

[0033] Fig. 2b is a schematic representation of a part of the hybrid circuit breaker device in an open state,

[0034] Fig. 3a schematically shows a top view of a mechanical interrupter of the hybrid circuit breaker device,

[0035] Fig. 3b shows a schematic top view of a slightly modified mechanical interrupter of the hybrid circuit breaker device,

[0036] Fig. 4 schematically shows a magnetically sensitive tripping element of the mechanical circuit breaker with a schematic internal structure,

[0037] Fig. 5 is a schematic flow diagram of a method for operating the hybrid circuit breaker device,

[0038] Fig. 6 schematic time-dependent current curves through components of the hybrid contactor,

[0039] Fig. 7 is a schematic diagram of the hybrid contactor with the hybrid circuit breaker device and with an additional electromagnet and

[0040] Fig. 8 is a schematic diagram of the hybrid contactor with the hybrid circuit breaker device and with an additional capacitor.

[0041] Description of the embodiments

[0042] Fig. 1 shows a schematic circuit diagram of a hybrid contactor

[0043] 28. The hybrid contactor 28 is designed as a DC hybrid contactor. The hybrid contactor 28 is provided for rapid, automatic interruption of a circuit / current flow in the event of a fault. The hybrid contactor 28 comprises a hybrid circuit breaker device 30. The hybrid circuit breaker device 30 is designed as a DC hybrid circuit breaker device. The hybrid circuit breaker device 30 comprises a mechanical interruption switch 10. In the event of a trip, the mechanical interruption switch 10 has an opening time 36 (cf. Fig. 4) of less than 400 ps, ​​preferably even less than 200 ps. The mechanical interruption switch 10 is provided to open the electrical contact particularly quickly and / or automatically in the event of a fault. When the mechanical interruption switch 10 opens, a short arc is created.When the mechanical circuit breaker 10 opens, the electrical voltage drop across the mechanical circuit breaker 10 increases. The hybrid circuit breaker device 30 comprises a semiconductor circuit breaker 12. The semiconductor circuit breaker 12 is designed as a semiconductor relay (e.g., MOSFET or IGBT). The semiconductor circuit breaker 12 is electrically connected in parallel to the mechanical circuit breaker 10. Due to the electrical parallel connection of the semiconductor circuit breaker 12 to the mechanical circuit breaker 10, the electrical voltage drop across the semiconductor circuit breaker 12 always corresponds to the electrical voltage drop across the mechanical circuit breaker 10. The semiconductor circuit breaker 12 is designed to take over the current from the opening mechanical circuit breaker 10 starting at a certain minimum arc voltage.

[0044] The hybrid contactor 28 comprises a varistor 32. The varistor 32 is electrically connected in parallel to the hybrid circuit breaker device 30. The varistor 32 is electrically connected in parallel to the mechanical interrupter 10. The varistor 32 is electrically connected in parallel to the semiconductor circuit breaker 12. Due to the electrical parallel connection of the semiconductor circuit breaker 12 to the mechanical interrupter 10, the electrical voltage drop across the varistor 32 always corresponds to the electrical voltage drop across the mechanical interrupter 10. The varistor 32 is provided to reduce the current taken over by the semiconductor circuit breaker 12 to zero. The hybrid circuit breaker device 30 has a further mechanical interrupter 22. The further mechanical interrupter 22 is arranged in series with the semiconductor circuit breaker 12.The additional mechanical interruption switch 22 is arranged in series with the mechanical interruption switch 10. The additional mechanical interruption switch 22 is arranged in series with the varistor 32. The additional mechanical interruption switch 22 is designed to trigger with a time delay relative to the mechanical interruption switch 10. The additional mechanical interruption switch 22 is designed to trigger more slowly than the mechanical interruption switch 10. The additional mechanical interruption switch 22 is designed to create and maintain galvanic isolation of the circuit.

[0045] The hybrid contactor 28 has a maintenance switch 38. The maintenance switch 38 is provided to allow the opening of a circuit monitored by the hybrid circuit breaker device 30. The maintenance switch 38 is provided for a load-free opening of the circuit. The maintenance switch 38 can be opened, for example, to enable maintenance of the circuit. The maintenance switch 38 can be operated manually or automatically. The maintenance switch 38 is designed separately from the hybrid circuit breaker device 30. The mechanical interruption switch 10 is designed completely coil-free. The hybrid circuit breaker device 30 is designed free of choke coils. The hybrid contactor 28 is designed free of choke coils.

[0046] Figures 2a and 2b show a schematic representation of part of the

[0047] Hybrid circuit breaker device 30, which provides the mechanical

[0048] Interrupter switch 10 and the further mechanical interrupter switch 22. The mechanical interrupter switch 10 has a trigger element 14. The trigger element 14 is magnetic field sensitive. The trigger element 14 is arranged in the vicinity of a current-carrying conductor section 40 of the circuit. The trigger element 14 is arranged parallel to the current-carrying conductor section 40. The trigger element 14 is arranged such that the longitudinal extension directions of the trigger element 14 and conductor section 40 run at least substantially parallel to one another. The trigger element 14 is provided to generate an interruption in the circuit by changing its shape. The trigger element 14 is provided to generate an interruption in the circuit by changing its length. The trigger element 14 is provided to actuate a switch that physically disconnects the circuit by changing its length and / or shape.In Figures 2a and 2b, the switch is shown as a toggle switch by way of example. The trigger element 14 is partially formed from a magnetic shape memory alloy 16. Alternatively, the trigger element 14 can also be formed entirely or almost entirely from a magnetic shape memory alloy 16. The trigger element 14 is oriented and / or arranged such that a magnetic field caused by a change in the current flow in the conductor piece 40 is guided through the trigger element 14 in such a way that a change in the shape of the magnetic shape memory alloy 16 is brought about. The magnetic shape memory alloy 16 is designed as a magnetic high-temperature shape memory alloy. In Figure 2a, the trigger element 14 is in an undeformed state. In Figure 2b, the trigger element 14 is in a deformed state. In Figure2b, the trigger element 14 has an elongated shape compared to the undeformed state. Fig. 2a shows the state of the mechanical interruption switch 10 during normal operation. Fig. 2b shows the state of the mechanical interruption switch 10 in the event of a fault. Fig. 2a shows the state of the further mechanical interruption switch 22 during normal operation. The further mechanical interruption switch 22 is closed. Fig. 2b shows the state of the further mechanical interruption switch 22 in the event of a fault. The further mechanical interruption switch 22 is open. The further mechanical interruption switch 22 has a trigger element 26, which is at least partially formed from a magnetic shape memory alloy 16. The trigger element 14 of the mechanical interruption switch 10 simultaneously also represents the trigger element 26 of the further mechanical interruption switch 22.The change in length of the trigger element 14 also triggers the opening of the additional mechanical interruption switch 22. Alternatively, the additional mechanical interruption switch 22 could also be opened by a separate trigger element from the trigger element 14, in particular with a function comparable to that of the trigger element 14.

[0049] The hybrid circuit breaker device 30 has a delay unit 24. The delay unit 24 is provided to temporally delay an effect of the triggering element 14, 26 on the further mechanical interruption switch 22 relative to an effect of the triggering element 14, 26 on the mechanical interruption switch 10. The delay unit 24 is embodied, for example, by a toggle switch spaced apart from the further mechanical interruption switch 22. Alternative configurations for delay units 24 that fulfill the same inventive task are conceivable and can be derived by a person skilled in the art from their specialist knowledge.

[0050] Figures 3a and 3b schematically show a top view of the mechanical interrupter 10. The path of the magnetic field generated by the conductor piece 40 is indicated by magnetic field lines 42. The magnetic field lines 42 traverse the trigger element 14 perpendicular to its longitudinal extent. The mechanical interrupter 10 shown in Fig. 3a is designed free of magnetic flux-conducting components, apart from the magnetic shape memory alloy 16 of the trigger element 14. Alternatively, however, the conductor piece 40 can also be surrounded by a magnetic flux-conducting sleeve 44, into which the trigger element 14 is inserted, as shown in Figure 3b.

[0051] As shown by way of example in Figures 3a and 3b, the mechanical interrupter switch 10 can comprise a thermosensitive trigger element 26 in addition to the magnetic field-sensitive trigger element 14. The thermosensitive trigger element 26 is intended to interrupt the circuit in the event of an overload. The thermosensitive trigger element 26 is intended to undergo a change in length when a limit temperature is exceeded, thereby opening the mechanical interrupter switch 10, in particular analogous to the function of the magnetically sensitive trigger element 14. The thermosensitive trigger element 26 consists at least largely, preferably entirely or almost entirely, of a thermal shape memory alloy 52.

[0052] Figure 4 shows the magnetically sensitive trigger element 14 with a schematic internal structure. The trigger element 14 comprises a plurality of twin boundaries 18, 20. The twin boundaries 18, 20 can be created by a (mechanical) surface treatment of the magnetic shape memory alloy 16. The twin boundaries 18, 20 are coherently movable. The distances 46 between adjacent twin boundaries 18, 20 of the trigger element 14 are less than 300 pm, preferably less than 150 pm.

[0053] Figure 5 shows a schematic flow diagram of a method for operating the hybrid circuit breaker device 30. In at least one method step 48, the mechanical interruption switch 10 is actuated in the event of an overcurrent by a change in the shape of the magnetic shape memory alloy 16. In at least one further method step 50, the mechanical interruption switch 10 is actuated in the event of an overload by a change in the shape of the thermal shape memory alloy 52.

[0054] Figure 6 schematically shows time-dependent current waveforms 58 through components of the hybrid contactor 28. The basic mode of operation of the hybrid contactor 28 will be briefly explained below with reference to Figure 6. A time is plotted on an abscissa 54 in Fig. 6. The times ti to ts are specifically marked on the abscissa 54. Current intensities such as can occur at the components of the hybrid contactor 28 in the event of a fault are plotted on an ordinate 56 in Fig. 6. From top to bottom, the following current waveforms 58 are shown in Fig. 6: a) total current through the hybrid contactor 28; b) current through the mechanical interrupter switch 10; c) current through the semiconductor circuit breaker 12 and d) current through the varistor 32. From the beginning up to time ti, the current intensity corresponds to a nominal value of normal operation and flows entirely via the path of the mechanical interrupter switch 10, which is closed during normal operation.The fault occurs at time t1. The fault leads to a rapid increase in the current flowing through the mechanical circuit breaker 10. The resulting magnetic field deforms the magnetic shape memory alloy 16 of the tripping element 14 and thus opens the mechanical circuit breaker 10. The opening of the mechanical circuit breaker 10 creates an arc and a corresponding arc voltage. The arc voltage also simultaneously occurs at the semiconductor circuit breaker 12. Once a minimum voltage is exceeded at the semiconductor circuit breaker 12 at time t2, the semiconductor circuit breaker 12 allows current to flow. The period between times t1 and t2 is called the opening time 36. By time t3, the current flow is completely commutated from the mechanical circuit breaker 10 to the semiconductor circuit breaker 12.After the current has been fully commutated to the semiconductor circuit breaker 12, the mechanical interrupter 10 opens completely. At time t4, the semiconductor circuit breaker 12 is closed / switched off. This occurs as soon as the mechanical interrupter 10 is safely opened wide enough. The current in the path of the semiconductor circuit breaker 12 drops almost suddenly to zero. The current is completely commutated to the varistor 32. Until time ts, the varistor 32 conducts the current to zero. After time ts, the other mechanical interrupter 22 opens with a time delay.

[0055] Figures 7 and 8 each show schematic circuit diagrams of hybrid contactors 28', 28" with additional elements for controlled opening of the circuit under load. Fig. 7 shows an embodiment of the hybrid contactor 28' which includes an electromagnet 34. The electromagnet 34 is designed and / or arranged such that a magnetic field generated by the electromagnet 34 can actuate the tripping element 14 of the mechanical interrupter switch 10. If the mechanical interrupter switch 10 is to be opened in a controlled manner, the electromagnet 34 is activated and generates a magnetic field which causes a change in the shape of the tripping element 14 comparable to a short circuit.8 shows an embodiment of the hybrid contactor 28", which comprises a capacitor 60, which is electrically connected in parallel with the mechanical interrupter switch 10 and which can be discharged by means of a switch 62 of the hybrid circuit breaker device 30. The capacitor 60 is charged during normal operation. When the switch 62 is closed, the capacitor 60 discharges suddenly and generates a high current flow, at least briefly. The high current gradient during the discharge of the capacitor 60 generates a magnetic field large enough to actuate the tripping element 14 of the mechanical interrupter switch 10. If the mechanical interrupter switch 10 is to be opened in a controlled manner, the switch 62 is closed, and the discharge of the capacitor 60 generates a magnetic field, which causes a change in the shape of the tripping element 14 comparable to a real short circuit.The electromagnet 34 of the embodiment of Fig. 7 and the capacitor 60 of the embodiment of Fig. 8 are each provided to allow a controlled opening of the circuit monitored by the hybrid circuit breaker device 30.

[0056] Reference symbol

[0057] 10 Mechanical circuit breaker

[0058] 12 semiconductor circuit breakers

[0059] 14 trigger element

[0060] 16 magnetic shape memory alloy

[0061] 18 Twin Border

[0062] 20 Twin Border

[0063] 22 Additional mechanical circuit breaker

[0064] 24 Delay unit

[0065] 26 trigger element

[0066] 28 Hybrid contactor

[0067] 30 Hybrid circuit breaker device

[0068] 32 varistors

[0069] 34 Electromagnet

[0070] 36 Opening hours

[0071] 38 maintenance switches

[0072] 40 ladder section

[0073] 42 magnetic field line

[0074] 44 cuff

[0075] 46 distance

[0076] 48 process steps

[0077] 50 process steps

[0078] 52 Thermal shape memory alloy

[0079] 54 Abscissa

[0080] 56 ordinates

[0081] 58 Current flow

[0082] 60 capacitor

[0083] 62 switches

Claims

Claims: Hybrid circuit breaker device (30), in particular a DC hybrid circuit breaker device, comprising at least one mechanical interrupt switch (10) and at least one semiconductor circuit breaker (12), in particular a semiconductor relay, connected electrically in parallel to the mechanical interrupt switch (10), characterized in that the mechanical interrupt switch (10) has a tripping element (14), in particular a magnetic field-sensitive element, which is at least partially formed from a magnetic shape-memory alloy (16). Hybrid circuit breaker device (30) according to claim 1, characterized in that the mechanical interrupt switch (10) has an opening time (36) of less than 400 ps, ​​preferably less than 200 ps, ​​in a tripping event.Hybrid circuit breaker device (30) according to claim 1 or 2, characterized in that the tripping element (14), in particular produced by a (mechanical) surface treatment of the magnetic shape memory alloy (16), comprises a plurality of coherently movable twin boundaries (18, 20).

4. Hybrid circuit breaker device (30) according to claim 3, characterized in that the distances (46) of adjacent twin boundaries (18, 20) of the tripping element (14) are less than 300 pm, preferably less than 150 pm.

5. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized in that the mechanical interrupt switch (10) is designed without coils.

6. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized by a design free of a choke coil.

7. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized in that the mechanical interrupt switch (10), apart from the magnetic shape memory alloy (16) of the release element (14), is designed to be at least substantially free of magnetic flux-conducting components.

8. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized by at least one further mechanical interrupt switch (22) arranged in series at least with the semiconductor circuit breaker (12), which is designed to trigger with a time delay and / or slower than the mechanical interrupt switch (10).

9. Hybrid circuit breaker device (30) according to claim 8, characterized in that the further mechanical interrupt switch (22) has a release element (26) which is at least partially formed from a magnetic shape memory alloy (16).

10. Hybrid circuit breaker device (30) according to claim 9, characterized in that the release element (14) of the mechanical break switch (10) also represents the release element (26) of the further mechanical break switch (22).

11. Hybrid circuit breaker device (30) according to claim 10, characterized by a delay unit (24) which is provided to delay the effect of the release element (14, 26) on the further mechanical interrupt switch (22) relative to the effect of the release element (14, 26) on the mechanical interrupt switch (10).

12. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized in that the magnetic shape memory alloy (16) is designed as a high-temperature magnetic shape memory alloy.

13. Hybrid circuit breaker device (30) according to one of the preceding claims, characterized in that the mechanical interrupt switch (10) comprises, in particular in addition to the magnetic field-sensitive release element (14), a thermosensitive release element (26).

14. Hybrid contactor (28), in particular DC hybrid contactor, with the hybrid protection switch device (30) according to one of the preceding claims, and with at least one varistor (32) connected electrically in parallel to the hybrid protection switch device (30). Hybrid contactor (28) according to claim 14, characterized by an electromagnet (34) and / or by a capacitor (60) electrically connected in parallel to the mechanical interrupt switch (10) and dischargeable by means of a switch (62), each of which is at least provided for a controlled opening of the To allow the operation of a hybrid circuit breaker device (30) of a monitored circuit. Method for operating a hybrid circuit breaker device (30), in particular a DC hybrid circuit breaker device, preferably according to one of claims 1 to 13, with at least one mechanical Interruption switch (10) and with at least one semiconductor protection switch (12), in particular a semiconductor relay, connected electrically in parallel to the mechanical interruption switch (10), characterized in that the mechanical interruption switch (10) is interrupted in the event of an overcurrent by a Shape change of a magnetic shape memory alloy (16) is actuated.

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