Method for tapping a voltage for a rogowski coil

Abstract

The invention relates to a method for securing a Rogowski coil (150) to a busbar (160). According to one aspect of the method, a device (100) comprises at least one connecting element (102) which is mechanically connected or can be mechanically connected to the Rogowski coil (150). The device (100) has an opening (104) for securing the device (100) to the busbar (160). The device (100) additionally has a voltage signal output (120) which is connected or can be connected to the busbar (160) in an electrically conductive manner at the opening (104).

Description

[0001] Voltage tapping technique for a Rogowski coil

[0002] The invention relates to a technique for attaching a Rogowski coil. In particular, a device for attaching a Rogowski coil to a busbar, a system comprising a Rogowski coil and a corresponding attachment device, and a measurement method using a corresponding device are disclosed.

[0003] European Patent EP 2 990 808 B1 describes a mounting device for a Rogowski coil, which is used to attach it to electrical conductors such as busbars or cables for measuring alternating currents. The Rogowski coil is a toroidal measuring coil that generally does not contain a ferromagnetic core and is placed around the conductor to be measured in order to detect the alternating current flowing through it. The core of the teaching of European Patent EP 2 990 808 B1 is the conceptual separation of the mounting device into two main components. On the one hand, a housing part is directly connected to the Rogowski coil and can contain the evaluation electronics for the coil's signals. On the other hand, the mounting part is attached to the power line device (busbar or cable) and then connected to the housing part.A key advantage is the modular design and the ability to rotate it, for example with a ratchet mechanism.

[0004] However, existing devices only allow for the installation of the Rogowski coil. A voltage measurement would be particularly desirable for power measurement. However, this requires the complex assembly of a system consisting of a current measuring point with a Rogowski coil and a voltage measuring point. Furthermore, there is often no space available for an additional terminal point on the busbar for voltage measurement directly at the Rogowski coil mounting point, or it is only accessible with further modifications. Furthermore, spatially separating the current measuring point and the voltage measuring point makes the circuit layout confusing, leads to additional wiring, and can result in inconsistent and erroneous power measurements, for example, due to a voltage drop between the two measuring points or crosstalk in the wiring.

[0005] The invention is therefore based on the object of specifying a technique for attaching a Rogowski coil which eliminates the need to install a voltage measuring point.

[0006] The object is achieved by the features of the independent claims. Expedient embodiments and advantageous further developments of the invention are specified in the dependent claims.

[0007] Embodiments of the invention are described below with partial reference to the figures.

[0008] One aspect of the device relates to a device for attaching a Rogowski coil to a busbar. The device comprises at least one connecting element that is or can be mechanically connected to the Rogowski coil. Furthermore, the device comprises a recess for attaching the device to the busbar. A voltage signal output of the device is or can be electrically connected to the busbar at the recess.

[0009] The voltage signal output can be configured to output a voltage signal that represents a voltage tapped from the busbar at the recess. For example, a potential of the voltage signal can be equal to the potential of the busbar at the recess.

[0010] Thus, when using embodiments of the device for mounting the Rogowski coil, the installation of an additional voltage measuring point is eliminated. This reduces the installation space along the busbar and eliminates voltage drops due to inconsistent measurements at different points along the busbar.

[0011] The recess may have a contact surface on at least one inner side which is electrically connected to the voltage signal output, for example via a voltage signal conductor through a housing of the device or via a shaft region of a spindle screw.

[0012] The recess may have an opening on an inner side, for example, on one of the aforementioned contact surfaces, for the passage of a spindle screw. The spindle screw may be electrically connected to the voltage signal output, for example, via a voltage signal conductor through a housing of the device or via a shaft portion of the spindle screw itself.

[0013] The spindle screw can be electrically conductive, for example, metallic. This allows for mechanical force connection and electrical voltage tapping at a single point on the busbar.

[0014] The voltage signal output can be detachably connected to the device or connectable. Optionally, the device housing has an opening for receiving the voltage signal conductor attached to the voltage signal output. Alternatively or additionally, the voltage signal conductor protrudes from the device housing, and the voltage signal output is plugged or pluggable onto the voltage signal conductor attached to the housing.

[0015] This can enable modularity. The ability to separate the voltage signal output facilitates the replacement or upgrade of components without having to replace the entire mounting system. This achieves high flexibility in the configuration of the measurement system. Furthermore, it can improve maintainability. In the event of a malfunction, the voltage signal output can be quickly disassembled and repaired or replaced with another module, thus minimizing downtime of the overall system.

[0016] This can also allow for device customization. Users can configure the device according to their specific requirements, for example, by deciding whether or not a voltage signal output is required.

[0017] Furthermore, material resources can be used more efficiently. For example, the ability to remove or add individual voltage signal outputs allows a measurement system to be precisely configured. Furthermore, the entire device does not need to be replaced for minor adjustments.

[0018] The option that the housing of the device has an opening to receive the voltage signal conductor attached to the voltage signal output or, conversely, the voltage signal conductor protrudes from the housing and the voltage signal output is connected to the

[0019] A plug-in or plug-in voltage signal conductor can simplify installation and removal. Plugging the voltage signal output onto the voltage signal conductor enables quick, tool-free installation or removal.

[0020] Furthermore, the voltage signal conductor integrated in the plug-in voltage signal output can improve electrical safety by eliminating exposed contacts on the mounting device.

[0021] The spindle screw can be connected to a knurled wheel for manual length adjustment of the spindle screw end protruding into the recess. For example, the screw end can have a hardened tip or a contact surface. For reliable voltage tapping, the hardened tip of the spindle screw can be pressed into the surface of the busbar, or the contact surface can be pressed against the busbar using the spindle screw.

[0022] The spindle screw can be screwed into an internal thread of the device (e.g., an electrically conductive structure of the recess) and allow precise length adjustment by turning the spindle screw. Since the thread flanks of the spindle screw and the internal thread come into direct contact and form a mechanical connection (which allows linear movement), the electrically conductive connection to the voltage signal output can be established via the internal thread (e.g., via the electrically conductive structure of the recess).

[0023] The change in length can be a length adjustment to a width of the busbar that is smaller than a width (measured parallel to the longitudinal direction of the spindle screw) of the recess.

[0024] The use of the spindle screw with knurled wheel allows for sensitive adjustment of the contact pressure through the translation of the spindle thread, allowing for precise adjustment of the contact force between the device and the busbar and thus also for reliable electrical contact. This is important for stable mechanical contact and consistently high measurement accuracy.

[0025] Furthermore, this mechanism enables quick assembly and disassembly. The screw can be tightened or loosened quickly and without additional tools, thus accelerating the assembly and disassembly of the device. Furthermore, since no tool is required, there is no risk of a conductive tool accidentally causing short circuits or other electrical disturbances. A hardened tip can press into the surface of the busbar, providing a secure mechanical hold and a good electrical connection. A contact pad provides a larger area for electrical contact, thereby reducing contact resistance, which in turn leads to more accurate voltage measurements.

[0026] Manual adjustment via a thumbwheel can reduce the risk of applying too much pressure, which could damage the busbar or other components.

[0027] The voltage signal output may comprise a voltage signal conductor extending through a housing (e.g., a wall of the housing). The voltage signal conductor may terminate in a voltage signal terminal of the voltage signal output, such as a socket, a plug-in terminal, and / or a voltage signal line (e.g., soldered or permanently clamped) for transmitting a voltage signal indicative of a busbar voltage.

[0028] The voltage signal line can be detachably connected to the voltage signal connection (for example by means of the socket or the plug-in terminal).

[0029] The voltage signal output can be integrated in a coil head of the Rogowski coil, for example for the combined output and / or evaluation of a voltage signal tapped at the recess and a current signal of the Rogowski coil.

[0030] The coil head can serve as a current signal output and a voltage signal output. Alternatively or additionally, the combined evaluation can include a determination of electrical power and / or a power factor. The Rogowski coil can have a detachable end that can be connected to the coil head via a bayonet lock, allowing the Rogowski coil to be placed (preferably simply) around the busbar and secured.

[0031] The spindle screw of the device can have a shaft portion that acts as a voltage signal conductor, conducting a voltage signal tapped at the recess to the integrated voltage signal output in the coil head. For example, a knurled wheel of the spindle screw can be arranged between the shaft portion and the recess. Alternatively or additionally, the shaft portion can be arranged concentrically between several of the at least one connecting elements. This allows the voltage signal to be transmitted to a rotatable coil head.

[0032] The coil head can have a common interface for a combined current signal and voltage signal line, through which the voltage signal tapped at the recess and a current signal from the Rogowski coil can be transmitted. This allows for clear and functionally grouped signaling.

[0033] The voltage signal output can comprise an analog-to-digital converter and a network interface for outputting a data packet indicating the voltage signal tapped at the recess. For example, the voltage signal output integrated in the coil head can further comprise an analog-to-digital converter of the current signal of the Rogowski coil, and the network interface can further be configured to output a data packet indicating the current signal and / or the electrical power.

[0034] The device can further comprise at least one sensor at the recess for detecting temperature and / or mechanical stress, e.g., mechanical stress or vibration, on the busbar. The at least one sensor can be communicatively connected to the voltage signal output to output sensor signals from the at least one sensor together with the voltage signal detected at the recess. For example, the sensor signals can be integrated into the data packet output by the network interface.

[0035] The sensor signals can be used to monitor the thermal condition and / or mechanical integrity of the busbar.

[0036] One system aspect relates to a system comprising a Rogowski coil and a device according to the device aspect. The system comprises the device according to the device aspect and a Rogowski coil attached to a busbar by means of the device for detecting a current flowing through the busbar.

[0037] A coil end of the Rogowski coil and / or the voltage signal output of the device can comprise an evaluation unit configured to detect a current signal from the Rogowski coil indicating the current and the voltage signal of the device and output a power signal indicating a power and / or a phase angle. The phase angle can be a phase angle between the current (according to the current signal) and the voltage (according to the voltage signal) of the busbar.

[0038] The voltage signal output of the device for the voltage signal can comprise an interface between the device and the coil head. Alternatively or additionally, the voltage signal output for the voltage signal can comprise a socket arranged in the coil head. Alternatively or additionally, the coil head can comprise an interface for the voltage signal, optionally for accommodating the shaft portion of the spindle screw.

[0039] One method aspect relates to a method for measuring electrical power transported (e.g., provided) by a busbar. The method comprises the step of attaching a Rogowski coil to a busbar, which extends through a recess of the device of the device aspect. The method further comprises the step of combined detection of a current of the busbar by means of the Rogowski coil and a voltage of the busbar by means of the device for measuring the electrical power transported by the busbar.

[0040] The invention is explained in more detail below with reference to the drawings using preferred embodiments.

[0041] They show:

[0042] Fig. 1 is a perspective side view of a first embodiment of a device for attaching a Rogowski coil to a busbar with a voltage signal output;

[0043] Fig. 2 is a perspective side view of a variant of the first embodiment of a device for fastening a Rogowski coil to a busbar with a voltage signal output;

[0044] Fig. 3 is a side view of a second embodiment of a device for attaching a Rogowski coil to a busbar with a voltage signal output;

[0045] Fig. 4 is a side view, rotated by 90° relative to Fig. 3, of the second embodiment of a device for fastening a Rogowski coil to a busbar with a voltage signal output;

[0046] Fig. 5 is a perspective view of a system with a Rogowski coil mounted on a busbar using the first or second embodiment of the device; Fig. 6 is a side view of a third embodiment of a device for mounting a Rogowski coil on a busbar with a voltage signal output; and

[0047] Fig. 7 is a perspective view of a system with a Rogowski coil mounted on a busbar by means of the third embodiment of the device.

[0048] Fig. 1 shows a schematic spatial view of a first embodiment of a device generally designated by reference numeral 100.

[0049] The device 100 is used to attach a Rogowski coil to a busbar, thereby enabling the acquisition of current measurements and, depending on the design, parallel voltage measurements. For this purpose, the device 100 has at least one connecting element 102, which allows a (preferably non-destructively detachable) mechanical connection of the device 100 to (for example, a coil head) of the Rogowski coil. The at least one connecting element 102 can have two projections with locking lugs. The projections can be segments of a cylinder to enable rotation of the coil head.

[0050] Thanks to the at least one connecting element 102, the device 100 allows the Rogowski coil to be fixed in the correct position for precise and reliable measurement. For example, a pair of opposing connecting elements 102 enables various rotational positions of the coil around the vertical axis in Fig. 1, particularly depending on the available space between several parallel busbars.

[0051] A recess 104 of the device 100 is designed to fit over the busbar (for example, over a longitudinal edge of the busbar), allowing the device 100 to be firmly positioned on the busbar. A housing 106 encloses at least the recess 104. The necessary stability of the recess 104 for the frictional connection between the device 100 and the busbar can be provided by the housing 106 or an internal, preferably metallic, structure. The housing 106 can be made of an insulating material, particularly in the latter case. For example, a plastic can be overmolded around the internal structure.

[0052] Within the recess 104 are contact surfaces 108, which ensure an electrical connection to the busbar. By tapping voltage signals via the contact surfaces 108, the device 100 enables a combined current and voltage measurement, for example, a measurement of the power transported via the busbar and / or a determination of the power factor cos(cp).

[0053] An opening 110 is provided in the contact surfaces 108, through which a metal spindle screw 112 is guided into the area of ​​the recess 104. This screw 112 is part of the fastening mechanism and is operated via a knurled wheel 114 to adjust the contact pressure on the contact surfaces, for example, for frictional fastening. Alternatively or additionally, a tip of the (optionally hardened) spindle screw 112 can create an impression in the surface of the busbar by tightening the knurled wheel 114. This allows the device 100 to be positively fastened to the busbar and / or the electrical connection to the busbar can be ensured via the spindle screw 112 (alternatively or additionally to the contact surfaces 108).To facilitate operation of the spindle screw, a knurled wheel 114 is attached which can be manually rotated to tighten or loosen the screw 112, depending on whether the device 100 is to be installed on or removed from the busbar.

[0054] In any embodiment, the knurled wheel 114 may be a rotary wheel that is rotationally fixedly connected to the spindle screw 112 for manually rotating the spindle screw 112. Preferably, the knurled wheel 114 is accessible to thumb and fingers only on its circumferential surface and has a serration that is parallel to the axial direction (of rotation or of the spindle screw 112).

[0055] The device 100 provides a voltage signal that indicates the voltage (or potential) of the busbar. In the first exemplary embodiment, a voltage signal output 120 of the device 100, for example a pluggable (i.e., attached) terminal, is arranged outside the recess 104 (for example, on the housing 106) and is electrically connected to the contact surfaces 108 and / or the spindle screw 112 via a voltage signal conductor 122 that runs through the housing 106. The voltage signal connection 124, via a connection provided for this purpose—for example, a socket or a plug-in terminal—represents the interface to which a voltage signal line 126 can be connected in order to conduct the voltage signal to an evaluation device.

[0056] In an operating state, the Rogowski coil is guided (preferably once) around the busbar to detect the current flowing through the rail.

[0057] In a variant of each embodiment, the coil head 152 attached to the device 100 by the connecting elements 102 not only functions as a current signal output, but may alternatively or additionally also contain a voltage signal output.

[0058] A system incorporating the described device 100 enables comprehensive monitoring and measurement of the current and voltage profile in busbars, which is of crucial importance for many industrial applications.

[0059] Fig. 2 shows a schematic three-dimensional front view of a variant of the first embodiment of the device 100 for attaching a Rogowski coil to a busbar. The device 100 enables both mechanical fixation and electrical contacting of the busbar for the purpose of voltage measurement.

[0060] The at least one connecting element 102 establishes the reversible mechanical connection between the device 100 and the coil head of the Rogowski coil. The recess 104 is a through-hole. The recess 104 is lined on the inside (preferably circumferentially) with contact surfaces 108, which establish the electrical connection between the busbar and the voltage signal output 120.

[0061] Through the through-hole 104, the mechanical stresses of a force connection for fastening the device 100 to the busbar can be symmetrically supported. In particular, the sides of the through-hole 104 parallel to the force direction can be subjected to tensile stress (instead of bending stress as in the embodiment of Fig. 1).

[0062] The spindle screw 112, by means of the knurled wheel 114, enables a sensitive adjustment of the force-fit connection of the device 100 to the busbar and ensures secure mechanical fixation. A voltage signal conductor 122 is routed through the housing 106 via the voltage signal output 120, which can function as a plug-in terminal. This voltage signal conductor is electrically connected to the spindle screw 112 and / or the contact surfaces 108 on the one hand, and terminates in a voltage signal connection 124, to which a voltage signal line 126 can be clamped on the other.

[0063] Figures 3 and 4 show a second embodiment of the device 100 for attaching a Rogowski coil to a busbar. This device 100 serves both for mechanical mounting and for outputting an electrical voltage signal (optionally in addition to the current signal of the Rogowski coil) to an external measuring system. The device 100 has a connecting element 102 designed to be mechanically connected to a coil head of the Rogowski coil 150. This allows the device to be firmly coupled to the coil head, thus providing secure mechanical support for the measuring coil.

[0064] The recess 104 is specifically designed for attachment to a busbar 160. It is an integral part of the device 100 and ensures that the device 100 can be stably positioned on the busbar. This is crucial for achieving accurate measurement results, as precise or unchanging positioning of the Rogowski coil around the busbar is required.

[0065] In a variant of each embodiment, at the end of the spindle screw 112 projecting into the recess 104 there is a contact surface (for example a circular contact plate) movable by the spindle screw 112 for a surface contact with the busbar instead of a point contact pressing in the surface of the busbar.

[0066] A voltage signal output 120 is positioned at the recess 104 so that it can establish an electrically conductive connection with the busbar. In Figures 3 and 4, the voltage signal output 120 is implemented as a (for example, pluggable) terminal output. The output 120 allows the voltage signal tapped from the busbar to be routed to an external measuring system.

[0067] For example, the tapped voltage signal is routed to the voltage signal connection 124 of the voltage signal output 120 via a voltage signal conductor 122, which leads through the housing 106 of the recess 104. By way of example, in the following Fig. 3, this connection 124 is designed as a socket or plug-in terminal to which a voltage signal line 126 can be connected. This line 126 then transmits the voltage signal for further processing or display. In a variant of each exemplary embodiment, the voltage signal output 120 is attachable (i.e., pluggable). This allows a fastening device supplemented by the voltage signal conductor 122 to be used either solely for current measurement or, with the voltage signal output 120 plugged in, as a device 100 for integrated current and voltage measurement. Preferably, the voltage signal conductor 122 serves for the electrical and mechanical fastening of the voltage signal output 120.

[0068] For a second embodiment, Fig. 3 gives a frontal view of the voltage signal output 120, which is visible in partial section, as a terminal output, while Fig. 4 shows a view rotated by 90 degrees (around the vertical) in which the voltage signal conductor 122 extends.

[0069] A central aspect of the device 100 is the voltage signal output 120 on the outside of the device 100, to which a voltage signal line 126 can be connected. In the second embodiment shown, this output 120 comprises a attachable (i.e., pluggable) terminal output, which allows an electrical connection to the voltage signal conductor 122, which runs through the housing 106 of the recess 104. Thus, the voltage signal output 120 enables a simple and secure connection to measuring devices or other electronic systems.

[0070] In each embodiment, as an alternative to the terminal connection 124 shown (i.e., the plug-in terminal), the signal output 120 may have a plug-in socket 124 (e.g., for a banana plug on the voltage signal line 126).

[0071] The terminal output 120 includes, for example, a plug-in terminal 124 with a contact leaf spring and a counterplate, which together create a reliable, tensile-proof, electrically conductive connection by inserting the end of the voltage signal line 126 between the contact leaf spring and the counterplate. This allows the voltage signal line 126, which carries the voltage signal, to be securely fastened while ensuring minimal contact resistance.

[0072] The contact leaf spring serves as an elastic component that pivots away from the counter plate under the pressure of the line 126 and then exerts a constant contact force on the voltage signal line 126 to be connected, which ensures a permanently stable contact, which is also secured against tension on the line 126 by tilting due to the angular position of the edge of the contact leaf spring.

[0073] In a variant of each embodiment (with attachable or integral terminal output 120), the contact leaf spring of the plug-in terminal 124 is pivoted away from the counterplate and pre-tensioned after a push button on the terminal output 120 is pressed. A stop plate is located opposite an opening in the plug-in terminal 124 for inserting the voltage signal line 126. When the voltage signal line 126 presses against this stop plate, the pre-tensioned contact leaf spring is released and clamps the line 126 between the edge of the contact leaf spring and the counterplate. The line 126 is thus connected for voltage measurement. By pressing the push button again, the contact leaf spring pivots away from the counterplate, and the line 126 can be removed from the plug-in terminal 124.

[0074] In each embodiment, the device 100 can comprise an internal metallic structure whose surface includes the contact surfaces 108 and / or which has a bore with the internal thread of the spindle screw 112. Furthermore, in combination with each embodiment of the voltage signal output 120, the voltage signal conductor 122 (shown, for example, in the partial cross-section of Fig. 4) can be electrically conductively connected to the internal metallic structure. Fig. 5 shows a perspective view of a system 200 with a Rogowski coil 150, which is fastened to a busbar 160 by means of an embodiment (for example, the first or second embodiment) of the device 100. A fixed end 154 of the coil 150 is permanently connected to the coil head 152, i.e., a housing of the coil 150, which optionally includes evaluation electronics for a current signal.

[0075] A detachable end 156 of the coil 150 ensures that the coil 150 can be opened and placed around the busbar 160. Preferably, a bayonet lock 158 is provided on the coil head 152 to mechanically connect the detachable end 156 to the coil head 152. The two electrical terminals of the coil 150 are preferably connected via the fixed end 154 to the coil head 152. For example, the Rogowski coil 150 can be designed as a double helix or as a simple air-core coil with a coaxial return line.

[0076] Fig. 6 shows a side view of a third embodiment of the device 100 for attaching a Rogowski coil to a busbar. A shaft of the spindle screw 112 extends from the recess 104 beyond the knurled wheel 114 as a voltage signal conductor 122.

[0077] The voltage signal output 120 is implemented in the coil head 152. This allows the voltage signal and current signal to be connected and transmitted in a (multi-pole) signal line 126 on the coil head 152.

[0078] Fig. 7 shows a perspective view of an application of the third embodiment of the device 100 within a system 200 for combined current and voltage measurement on a busbar 160. The Rogowski coil 150 is guided around the busbar 160 with its fixed end 154 and its detachable end 156, with the detachable end 156 being secured by a bayonet lock 158. The coil head 152 with the voltage signal output 120 also serves as an interface for the Rogowski coil 150. The voltage signal line 126 is connected to the coil head 152 via the voltage signal connection socket 124.

[0079] Each embodiment of the device 100 can be configured to mechanically secure the Rogowski coil 150 using the recess 104 and the connecting element 102, and to tap a voltage at the recess 104 via an electrically conductive connection for power measurement. Thus, the voltage can be tapped directly at the location where the current is also measured. This eliminates the influence of voltage drops on the signal line or along the busbar.

[0080] In a variant of each embodiment, the voltage signal line 126 may be permanently connected to the voltage signal output 120.

[0081] Although the invention has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted. Furthermore, many modifications may be made to adapt a particular installation situation or material to the teachings of the invention. Consequently, the invention is not limited to the disclosed embodiments, but encompasses all embodiments falling within the scope of the appended claims.

[0082] List of reference symbols

[0083] 100 Device for attaching a Rogowski coil

[0084] 102 Connecting element for mechanical connection with coil head

[0085] 104 Recess for mounting on busbar

[0086] 106 Housing of the recess

[0087] 108 contact surfaces in recess

[0088] 110 Opening in contact surface

[0089] 112 spindle screw of the device

[0090] 114 Knurled wheel of the spindle screw

[0091] 120 Voltage signal output, e.g. terminal output and / or attachable

[0092] 122 Voltage signal conductor, e.g. through the housing or as shaft of the spindle screw

[0093] 124 Voltage signal connection, e.g. socket or plug-in terminal

[0094] 126 Voltage signal line

[0095] 150 Rogowski coil

[0096] 152 Coil head of the Rogowski coil, e.g. current signal output, optionally with voltage signal output

[0097] 154 Fixed end of Rogowski coil

[0098] 156 Detachable end of the Rogowski coil

[0099] 158 Bayonet closure of the detachable end

[0100] 160 busbar

[0101] 200 System for combined current and voltage measurement

Claims

Patent claims 1 . A device (100) for fastening a Rogowski coil (150) to a busbar (160), comprising: at least one connecting element (102) that is or can be mechanically connected to the Rogowski coil (150); a recess (104) for fastening the device (100) to the busbar (160); and a voltage signal output (120) that is or can be electrically connected to the busbar (160) at the recess (104).

2. Device (100) according to claim 1, wherein the recess (104) has on at least one inner side a contact surface (108) which is electrically conductively connected to the voltage signal output (120), optionally via a voltage signal conductor (122) through a housing (106) of the device (100).

3. Device (100) according to claim 1 or 2, wherein the recess (104) has on an inner side, optionally a contact surface (108), an opening (110) for the passage of a spindle screw (112) which is electrically conductively connected to the voltage signal output (120), optionally via a voltage signal conductor (122) through a housing (106) of the device (100).

4. Device (100) according to claim 2 or 3, wherein the voltage signal output (120) is detachably connected or connectable to the device (100), optionally wherein the housing (106) of the device (100) has an opening for receiving the voltage signal conductor (122) attached to the voltage signal output (120) or wherein the voltage signal conductor (122) protrudes from the housing (106) of the device (100) and the Voltage signal output (120) is plugged or can be plugged onto the voltage signal conductor (122) attached to the housing (106).

5. Device (100) according to claim 4, wherein the spindle screw (112) is connected in a rotationally fixed manner to a knurled wheel (114) for a manual change in the length of the end of the spindle screw (112) projecting into the recess (104), optionally wherein the screw end has a hardened tip or a contact surface.

6. Device according to one of claims 1 to 5, wherein the voltage signal output (120) has a voltage signal conductor (122) through a housing (106) and the voltage signal conductor (122) terminates in a voltage signal connection (124), optionally a socket, a plug-in terminal and / or a voltage signal line (126) for transmitting a voltage signal indicating a voltage of the busbar (160).

7. Device according to one of claims 1 to 6, wherein the voltage signal output (120) is integrated in a coil head (152) of the Rogowski coil (150), optionally for the combined output and / or evaluation of a voltage signal tapped at the recess (104) and a current signal of the Rogowski coil (150).

8. Device (100) according to claim 7, wherein the spindle screw (112) of the device (100) has a shaft region which, as a voltage signal conductor (122), carries a voltage signal tapped at the recess (104) to the integrated voltage signal output (120) in the coil head (152), optionally wherein a knurled wheel (114) of the spindle screw (112) is arranged between the shaft region and the recess (104) and / or wherein the shaft region is arranged concentrically between the connecting elements (102).

9. Device (100) according to one of claims 7 or 8, wherein the coil head (152) has a common interface for a combined current signal and voltage signal line (126), through which the voltage signal tapped at the recess (104) and a current signal of the Rogowski coil (150) can be transmitted.

10. Device according to one of claims 1 to 9, wherein the voltage signal output (120) comprises an analog-digital converter and a network interface for outputting a data packet which outputs the voltage signal tapped at the recess (104), optionally wherein the voltage signal output (120) integrated in the coil head (152) further comprises an analog-digital converter of the current signal of the Rogowski coil (150) and the network interface is further designed to output a data packet indicating the current signal and / or the electrical power.

11. Device (100) according to one of claims 1 to 10, wherein the device (100) further comprises at least one sensor on the recess (104) for detecting temperature and / or mechanical stress, optionally vibration, on the busbar (160), wherein the at least one sensor is communicatively connected to the voltage signal output (120) for outputting sensor signals of the at least one sensor together with the voltage signal detected at the recess (104), optionally wherein the sensor signals are integrated into the data packet output by the network interface.

12. System (200) comprising: a device (100) according to any one of claims 1 to 11 for detecting a voltage of a busbar (160); and a Rogowski coil (150) fastened to a busbar (160) by means of the device (100) for detecting a current through the busbar (160), an evaluation unit (120; 152), optionally in the voltage signal output (120) of the device (100) or in a coil head (152) of the Rogowski coil (150), which is designed to detect a current signal of the Rogowski coil indicating the current and a voltage signal of the device (100) indicating the voltage and to output a power signal indicating a power and / or a phase position.

13. The system (100, 200) of claim 12, wherein the coil head comprises an interface for the voltage signal, optionally for receiving the shaft portion of the spindle screw (112).

14. A method for measuring electrical power transported by a busbar (160), comprising: Attaching a Rogowski coil (150) to a busbar (160) extending through a recess (104) of the device (100) according to one of claims 1 to 11, and combined detection of a current of the busbar (160) by means of the Rogowski coil (150) and a voltage of the busbar (160) by means of the device (100) for measuring the electrical power transported by the busbar.

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