MODULAR CONNECTOR WITH CURRENT SENSOR ARRANGEMENT AND CURRENT MEASURING METHOD

Description

[0001] The present invention relates to the field of current measurement in a connector and in particular to a current sensor arrangement for measuring a respective current flow through electrical contacts or contact lines in a connector and to methods relating to the measurement of a respective current flow through electrical contacts or contact lines in a connector.

[0002] WO 2016 / 148022 A1 discloses an electrical current sensor designed to suppress measurement errors caused by the effect of an electric current flowing in another conductor adjacent to the conductor containing the electric current being measured, and to extend the frequency band of the electric current that can be measured. A magnetic sensor is positioned on a first imaginary line running latitudeally through the center of two magnetic shields and perpendicular to an imaginary plane, so that the detection value of the magnetic sensor is less affected by an external magnetic field. The first imaginary line running latitudeally through the center of the magnetic shields and the latitude of a conductor intersecting the first imaginary line are offset from each other by a distance.Therefore, even if the distance from the center of the conductor in the lateral direction to the electric current sensor is small, the frequency characteristics of the detection sensitivity of the magnetic sensor with respect to the frequency of the electric current that can be measured are improved on the high-pass side.

[0003] WO 94 / 27157 A1 relates to a current transformer based on the measurement of magnetic flux density and a method for its calibration. The transformer comprises a frame structure, a substantially ring-shaped magnetic circuit adapted to the frame structure, the ring shape of which has a gap to form an air gap and concentrate the magnetic flux onto the air gap, the ring-shaped magnetic circuit having an opening through which the current conductor to be measured can be passed, a Hall effect device can be inserted in the air gap, and an electromagnetic shielding structure surrounding the frame structure to prevent external interference fields from affecting the Hall effect device.According to WO 94 / 27157 A1, the electromagnetic shielding structure consists of a material that is substantially similar to that of the magnetic circuit, and both the magnetic circuit and the frame structure are shaped to accommodate either a straight current conductor or a winding structure with which the current measurement sensitivity can be multiplied.

[0004] US 2012 / 0319676 A1 discloses a detachable current sensor as an insulated and convenient device for measuring the current flowing through a cable, such as an AC power cable or a non-metallic sheathed cable. Information about the magnitude and / or phases of the currents and / or voltages flowing through the conductors is obtained by measuring the magnetic field at multiple circumferential positions around the cable using multiple semiconductor magnetic field sensors. A processing subsystem coupled to the multi-semiconductor magnetic field sensors determines information about the currents flowing in the cable conductors, including the current(s) and / or phases and the number of phases present in the cable, which can be part of a power measurement system used for energy monitoring and / or control purposes.

[0005] US 2015 / 0233980 A1 discloses a connector for attaching to a power supply unit with a switching element and for connecting to a mating connector of a cable harness, wherein the connector has a terminal block with an end section connected to an output terminal in a power supply housing, a receptacle attached to the housing and enclosing at least part of the connection terminal, a current sensor enclosed in the housing to detect a magnetic field generated by an electric current flowing through the connection terminal, and a signal line for transmitting an output signal from the current sensor.

[0006] EP 0 597 404 A2 discloses a method for determining conductor currents based on the measurement of vectorial magnetic field strengths in the sum magnetic field of a multi-conductor system. The individual conductor currents are calculated based on the measured field strengths. A suitable measuring arrangement for carrying out the method comprises a number of sensors equivalent to the number of conductors, or, in the case of a three-phase system, only two sensors, arranged in the sum magnetic field close to the three-wire system and within a magnetic shielding device, and connected to an evaluation unit.

[0007] EP 3 044 598 A1 discloses how to arrange a current sensor in a connector.

[0008] Furthermore, modular connector systems using a module frame, also known as a mounting frame or modular frame, have been disclosed in numerous printed materials and publications, shown at trade fairs, and are in use, particularly in industrial environments, in the form of heavy-duty connectors. For example, they are in the publications DE 10 2013 106 279 A1, DE 10 2012 110 907 A1, DE 10 2012 107 270 A1, DE 20 2013 103 611 U1, EP 2 510 590 A1, EP 2 510 589 A1, DE 20 2011 050 643 U1, EP 860 906 A2, DE 29 601 998 U1, EP 1 353 412 A2, DE 10 2015 104 562 A1, EP 3 067 993 A1, EP 1 026 788 A1, EP 2 979 326 A1, EP 2 917 974 A1 describes this. Several identical or different connector modules are held together in a module frame and installed in a connector housing. The function of a connector formed in this way is therefore very flexible. For example,Pneumatic modules, optical modules, and modules for transmitting electrical energy and / or analog and / or digital electrical signals are used in modular systems. Increasingly, connector modules are also taking on measurement and data processing tasks.

[0009] There is interest in further developing modular connectors in particular to make it possible to measure the current flowing through each of the individual contacts of the connector module.

[0010] One difficulty lies in the limited geometric space available within a connector or module. The electrical contacts and their associated wires are typically located close together, making it difficult to separate their magnetic fields using measurement techniques. These spatial constraints make it impractical to provide a separate conventional current sensor for each electrical contact or corresponding wire.

[0011] One objective underlying the present invention is to further develop connectors and, in particular, modular connector systems, as discussed above, towards improving the possibilities for measuring a respective current flow through electrical contacts or contact lines in the connector.

[0012] According to the invention, a modular connector as defined in claim 1 is proposed according to a first aspect.

[0013] According to a second aspect of the invention, a method for measuring a respective current flow through electrical contacts or contact lines in a modular connector is proposed, as defined in claim 5.

[0014] Part of the background of the present invention can be found in the following considerations.

[0015] The invention is based, firstly, on the realization that it is possible, by computational means, to determine the individual currents from the measurement signals of a suitable number of magnetic field sensors in a magnetic field resulting from the superposition of magnetic fields, each generated by the currents flowing through the contacts or contact leads of a connector. Secondly, it has been recognized that it is not necessary to individually shield the combination of a contact or contact lead with a respective magnetic field sensor from the environment, as was done in the prior art, since shielding is sufficient insofar as an area is shielded from external interference fields in which the magnetic field sensors and the electrical contacts or contact leads are located together.

[0016] According to the invention, at least a portion of the magnetic shield is designed for mounting in or on a retaining frame of the connector for receiving one or more modules of the connector and / or is part of the retaining frame (alternatively or additionally, the shield is attached to the housing and / or is part of the housing). A retaining frame, which in known modular connector solutions primarily serves to fix the modules to one another and, if necessary, to provide electrical contact (e.g., PE contact), can advantageously also serve as a carrier for the magnetic shield or even be designed as the magnetic shield itself.

[0017] In another advantageous embodiment of an aspect of the invention, the shielding area extends in a plane transverse to the direction of the respective current flows, even if a comparable current measurement is possible in planes tilted in this respect.

[0018] In another advantageous embodiment of an aspect of the invention, the magnetic field sensors are Hall elements or incorporate Hall elements. Hall elements are superior to other approaches, such as those based on coils or shunts, at least with regard to space optimization and miniaturization possibilities. Furthermore, it is sufficient to arrange a Hall element at a not too great distance from the contact or contact line, since direct spatial contact is not necessary.

[0019] In another advantageous embodiment of an aspect of the invention, the shielding comprises or consists of a soft magnetic material, in particular mu-metal.

[0020] Features of advantageous embodiments of the invention are defined in particular in the dependent claims, with further advantageous features, embodiments and configurations also being apparent to the person skilled in the art from the above explanation and the following discussion.

[0021] The present invention will now be further illustrated and explained with reference to exemplary embodiments shown in the figures. Here, Fig. 1 a schematic representation to illustrate a first embodiment of a current sensor arrangement according to the invention, Fig. 2 a further schematic representation to illustrate the first embodiment of a current sensor arrangement according to the invention, Fig. 3 a schematic representation of a mounting frame with a shield according to the first embodiment, Fig. 4 a schematic representation of a mounting frame with a shield according to a second embodiment, Fig. 5 a schematic representation of a mounting frame with a shield according to a third embodiment and Fig. 6 a schematic flow diagram of an embodiment of the method according to the invention for measuring a respective current flow.

[0022] In the accompanying drawings and the explanations relating to these drawings, corresponding or related elements are marked with corresponding or similar reference symbols, where appropriate, even if they are found in different embodiments.

[0023] Fig. 1 Figure 1 shows a schematic representation to illustrate a first embodiment of a current sensor arrangement according to the invention.

[0024] Fig. 1 Figure 1 shows a plug connection with contact modules 1, 1', each of which is held in a mounting frame 9. The contact modules 1, 1' make contact with L1, L2, L3, whose current flow is to be measured.

[0025] The current sensor assembly 15 comprises magnetic field sensors 5 and a computing module 3, which is also housed in one of the mounting frames 9. The current sensor assembly 15 further comprises a magnetic shield made of mu-metal (not shown for clarity, see Figure 1). Fig. 2 ), which place the magnetic field sensors 5 and the lines L1, L2, L3 in a plane perpendicular to the plane of the drawing. Fig. 1 surrounds.

[0026] Fig. 2 Figure 1 shows a further schematic representation to illustrate the first embodiment of a current sensor arrangement according to the invention.

[0027] The plane in which the magnetic shield 7 encloses the lines L1, L2, L3 and the corresponding magnetic field sensors 5 corresponds to the drawing plane in Fig. 2 .

[0028] The magnetic fields M1, M2, M3 generated by the current flow through conductors L1, L2, L3 are schematically indicated by concentric circles. These magnetic fields superimpose on each other within the shield 7, i.e., in shielding area A. The resulting magnetic field strength at the location of the magnetic field sensors 5 can be used to determine the respective underlying magnetic fields and thus to determine the current flows through conductors L1, L2, L3. For this purpose, the relative positions of the magnetic field sensors 5 to conductors L1, L2, L3, as well as the positions of the conductors themselves, must be known.

[0029] In Fig. 2 It is also indicated that an external interfering magnetic field Mx is prevented by the shielding 9 from reaching the shielding area A and thus the magnetic field sensors. Since this results in fewer or possibly no interfering influences to be considered when determining the respective magnetic fields M1, M2, M3 of the lines L1, L2, L3, the measurement results can be obtained more accurately and with less computational effort.

[0030] Fig. 3 shows a schematic representation of a mounting frame with a shield according to the first embodiment.

[0031] The retaining frame 9, in its construction consisting of two sections connected to each other by hinges and interlocked by means of projections and recesses, corresponds to a hinged frame 9 as disclosed, for example, in DE 10 2014 215 809 A1. The windows 11 provided in each section interact with corresponding lugs of the modules to be inserted (not shown) to fix them in place.

[0032] Unlike the articulated frames from DE 10 2014 215 809 A1, frame 9 is made of Fig. 3 Furthermore, it is provided with a shield 7, which is shown here as a separate component. The frame 9 is fitted with the modules, and the shield 7 is then placed onto the closed hinged frame and secured, for example, by a latch or similar mechanism.

[0033] Fig. 4 shows a schematic representation of a mounting frame with a shield according to a second embodiment.

[0034] The in Fig. 4 The mounting frame shown comprises, in addition to the hinged frame 9', two plates attached to the side surfaces of the hinged frame 9', for example by gluing, which together form the magnetic shield 7'.

[0035] Fig. 5 shows a schematic representation of a mounting frame with a shield according to a third embodiment.

[0036] The in Fig. 5 The mounting frame shown comprises, in addition to the hinged frame 9", two bodies attached to the side surfaces of the hinged frame 9", for example by adhesive, which together form the magnetic shield 7". This differs from the mounting frame shown. Fig. 4 Here, two angled sections are still present, so that when the hinged frame is closed, the parts of the magnetic shielding come almost into contact.

[0037] Fig. 6 Figure 1 shows a schematic flowchart of an embodiment of the inventive method for measuring a respective current flow.

[0038] The method for measuring the current flow through electrical contacts or contact lines in a connector initially comprises step 20 of arranging several magnetic field sensors, each designed to measure a magnetic field strength within the connector. Additionally, step 25 involves arranging a magnetic shield to protect a continuous shielding area from an external magnetic field.

[0039] The arrangement 25 of the magnetic shielding is such that the shielding at least partially surrounds the shielding area, wherein the multiple magnetic field sensors are arranged in the shielding area and the electrical contacts or contact lines extend together through the shielding area.

[0040] Furthermore, the procedure includes a (repeated) step 30 of determining the respective current flow from measurement signals of the magnetic field sensors.

[0041] The invention can be used, in particular, in connection with current measurement in a three-phase network, where a superposition of the magnetic fields in the three-phase network occurs within the connector. For current measurement, these superimposed magnetic fields are detected by, for example, three Hall sensors and transmitted to an embedded system of the connector. The superpositions are mathematically calculated using a system of equations and corrected for the respective values.

[0042] For accuracy, it is crucial that the Hall sensors are protected from external magnetic fields, i.e., interference. These interfering magnetic fields can be caused, for example, by power cables running along the housing.

[0043] Such a current sensor assembly, as described above, is first mounted in a hinged frame and then in the connector housing. Conventional housings or hinged frames cannot shield the sensors of the current sensor assembly from external magnetic fields.

[0044] Soft magnetic materials are particularly well-suited for shielding magnetic fields. These ferromagnetic materials, with their high permeability, can influence the course of magnetic field lines.

[0045] The hinged frame preferably serves as the carrier for this soft magnetic material. The shielding can have different shapes and locking mechanisms.

[0046] In current measurement within a connector, the present invention allows for high measurement accuracy because the Hall effect sensors, for example, are protected from external magnetic fields. This is preferably achieved using a magnetic shield in the form of a soft magnetic material, which is attached around or to the connector's hinge frame. With optimal design, the entire connector assembly and all sensors are simultaneously and completely shielded from external magnetic influences.

[0047] In conventional approaches, where each individual cable is equipped with its own dedicated magnetic field sensors with its own shielding, the complexity of the design increases with the number of cables (nesting of the individual components, compliance with air and creepage distances), making the manufacturing process of the individual components complex and expensive (e.g., overmolding of shielding material).

[0048] The simultaneous shielding of all sensors in the insulating body (e.g. in a 3-phase network) and the consideration of the mutual influence of the magnetic fields (e.g. in a 3-phase network), which is mathematically calculated and corrected, allows for an accurate determination of the respective flowing current, while the manufacturing and assembly process remains comparatively simple and a more compact design becomes possible. Bezugszeichenliste

[0049] 1, 1' Contact module 3 Computing module 5 Magnetic field sensor 7, 7', 7" Shielding 9, 9', 9" Hinged frame 11 Window 15 Current sensor arrangement 20 Arranging magnetic field sensors 25 Arranging a magnetic shield 30 Determining a current flow A Shielding area L1, L2, L3 Conductor M x Interference magnetic field M1, M2, M3 Magnetic field

Claims

1. Modular plug connector comprising a plurality of identical and / or different modules (1, 1'), each of which has at least one electrical contact or at least one contact lead (L1, L2, L3), and a holding frame (9, 9', 9") for receiving the modules (1, 1'), characterized in that the modular plug connector further comprises: a current sensor arrangement (15) for measuring a respective current flow through the electrical contacts or contact leads (L1, L2, L3), comprising: a plurality of magnetic field sensors (5) each adapted for measuring a magnetic field strength in the plug connector, a magnetic shield (7, 7', 7") that at least partially encloses a continuous shielded area (A) in order to shield it against an external magnetic field (Mx), and a calculation module (3) connected to the magnetic field sensors (5) , wherein the plurality of magnetic field sensors (5) are arranged in the shielded area (A) and the electrical contacts or contact leads (L1, L2, L3) extend collectively through the shielded area (A), at least part of the magnetic shield (7, 7', 7") is attached in or on the holding frame (9, 9', 9"), is part of the holding frame (9, 9', 9"), is attached in or on a housing of the plug connector and / or is part of the housing, the holding frame (9, 9', 9") accommodates the plurality of magnetic field sensors (5), and the calculation module (3) is configured to determine a respective current flow through each individual electrical contact or contact lead (L1, L2, L3) from the measurement signals of the plurality of magnetic field sensors (5) based on positions of the magnetic field sensors (5) relative to the electrical contacts or contact leads (L1, L2, L3) and their positions.

2. Modular plug connector according to claim 1, wherein the shielded area (A) extends in a plane transverse to the direction of the respective current flows.

3. Modular plug connector according to one of the preceding claims, wherein the magnetic field sensors (5) are or have Hall elements (5).

4. Modular plug connector according to one of the preceding claims, wherein the shield (7, 7', 7") includes or consists of a soft magnetic material, in particular mu-metal.

5. Method for measuring a respective current flow through electrical contacts or contact leads (L1, L2, L3) in a modular connector, wherein the modular plug connector comprises a plurality of identical and / or different modules (1, 1'), each of which has at least one electrical contact or at least one contact lead (L1, L2, L3), a holding frame (9, 9', 9") for receiving the modules (1, 1'), and a current sensor arrangement (15) for measuring a respective current flow through the electrical contacts or contact leads (L1, L2, L3) with a plurality of magnetic field sensors (5), each of which is adapted to measure a magnetic field strength in the plug connector, a magnetic shield (7, 7', 7") that at least partially encloses a continuous shielded area (A) in order to shield it against an external magnetic field (Mx), and a calculation module (3) connected to the magnetic field sensors (5), wherein at least a part of the magnetic shield (7, 7', 7") is attached in or on the holding frame (9, 9', 9"), is part of the holding frame (9, 9', 9"), is attached in or on a housing of the connector and / or is part of the housing, and the holding frame (9, 9', 9") accommodates the plurality of magnetic field sensors (5) and the method comprises the steps of: arranging (20) the plurality of magnetic field sensors (5) and arranging (25) the magnetic shield (7, 7', 7") to shield a continuous shielded area (A) from an external magnetic field (Mx ), wherein the arranging (25) of the magnetic shield (7, 7', 7") is carried out in such a way that the shield (7, 7', 7") at least partially encloses the shielded area (A), that the multiple magnetic field sensors (5) are arranged in the shielded area (A), and that the electrical contacts or contact leads (L1, L2, L3) extend collectively through the shielded area (A), characterized by a further step of determining (30) the respective current flow through each individual electrical contact or contact lead (L1, L2, L3) from the measurement signals of the multiple magnetic field sensors (5) based on positions of the magnetic field sensors (5) relative to the electrical contacts or contact leads (L1, L2, L3) and their positions.