Sensors, protection circuit breakers, charging cables, and charging stations

Abstract

The present invention relates to a sensor (100) that, compared to the prior art, has a through-opening with an inner width in the range of 25.2 to 32 mm, which on the one hand has higher sensitivity to residual current, particularly for determining the residual current in a bi-current sensitive manner, and on the other hand has a low possibility of erroneously detecting a residual current that is mistakenly determined to exceed the limit current when the monitored circuit is turned on. Furthermore, the present invention relates to a protective circuit breaker, a charging cable, and a charging station each having such a sensor.

Description

[Technical Field]

[0001] The present invention relates to a sensor, a protective circuit breaker, a charging cable, and a charging station. [Background technology]

[0002] Sensors for determining residual currents are known in various designs and for various applications, in particular because residual currents pose a danger to people and can cause fires.

[0003] Residual currents occur when there is a fault in a power supply network, especially in a circuit within the power supply network, which can cause a fault current to flow towards earth within the power supply network. Depending on the type and structure of the power supply network, residual currents can have AC and / or DC components.

[0004] The ever-expanding use of renewable energies, electromobility, variable speed electric machines and / or the like is leading to an increasing number of electrical systems interconnecting AC and DC supply networks, which makes the DC component of residual currents increasingly important.

[0005] Typically, especially in domestic electrical installations, only one fault current protective circuit breaker of type A is installed, which can monitor the domestic electrical network for residual currents containing AC components, but cannot detect or interrupt DC faults. However, the use of DC elements in domestic electrical installations is increasing, for example when charging electric vehicles or operating solar systems.

[0006] Therefore, there is a need for a current-sensitive monitoring of residual current, particularly during operation of a charging infrastructure or a solar inverter or the like, including a residual current sensor that shuts down the associated infrastructure if the detected measured value exceeds a limit value.

[0007] For the operation of charging infrastructures or solar inverters or the like, fault current circuit breakers of type B are known which are also able to detect and monitor the DC component of the residual current. However, fault current circuit breakers of type B are relatively expensive.

[0008] Dual-current-sensitive residual current sensors simultaneously monitor all currents flowing in the phase and neutral conductors and detect possible DC and AC faults. Depending on the application, the sensors can autonomously control the disconnection of the system in the event of an error or report the exceedance of a switching threshold to a higher-level control unit. Due to the very small permissible fault currents, excellent measurement accuracy is required. Furthermore, personnel safety requires particularly fast detection and subsequent shutdown of the entire system.

[0009] Known residual current sensors are based on a configuration in which a magnetic core is placed around the conductor being monitored, with an air gap between them. When a current flows, a magnetic field is induced by the magnetic core. In known configurations, a Hall element is placed in the air gap, generating an output voltage depending on the magnetic field strength. To improve measurement accuracy, a compensation winding can be attached to the magnetic core. This is achieved by electrically compensating for the magnetic field generated by the current being monitored and adjusting the zero position of the Hall sensor. The actual output signal of such a sensor then represents the current required by the compensation winding.

[0010] Furthermore, it is known to use so-called flux-gate sensors to measure the magnetic field generated by the flow of electric current. In this method, a primary coil is wound on a magnetic core and driven with an alternating current. An output signal, which depends on the residual current, is picked up by a secondary pick-up coil. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention is based on the problem of providing an improvement or alternative to the prior art. [Means for solving the problem]

[0012] According to a first aspect of the invention, there is provided a sensor for determining a residual current, in particular for determining the residual current in a bicurrent-sensitive manner, comprising: the sensor comprises a magnetic field sensitive element, a first main winding, a test winding and a shield, The magnetic field sensitive element has a through opening, and the through opening of the magnetic field sensitive element is formed as an oval having a cross section with two axes of symmetry; a first main winding and a test winding, each having a plurality of windings, surrounding the magnetic field sensitive element; the shield has an accommodation space configured to accommodate the magnetic field sensitive element, the first main winding, and the test winding; the containment space of the shield is radially defined by an outer shield wall and an inner shield wall; the inner wall of the shield defines a through-opening in the shield, the through-opening in the shield being formed as an oval having two axes of symmetry; the shielding body has a circumferentially extending gap in the region of the shielding body inner wall, the sensor is configured to be disposed around at least two electrical conductors; the through-opening of the magnetically sensitive element has at least one inner width along the axis of symmetry, The problem is solved by a sensor in which the through opening of the magnetically sensitive element has at least one inner width along the axis of symmetry, the at least one inner width being in the range of 25.2 to 32 mm, preferably 25.5 to 29 mm, particularly preferably 25.8 to 27 mm.

[0013] In this regard, the following terminology is mentioned: Firstly, it is expressly pointed out that within the scope of this patent application, indefinite articles and numerical descriptions such as "one", "two", etc. are to be generally understood as descriptions of "at least", i.e. "at least one", "at least two", etc., unless it is clear from the respective context or it is obvious or technically necessary for a person skilled in the art that there may be reference thereto "exactly one...", "exactly two...", etc.

[0014] Within the scope of this patent application, the expression "in particular" should always be understood as meaning that optional and preferred features are introduced by this expression. This expression should not be understood as "strictly" or "i.e."

[0015] A "sensor", or even a "detector", is a technical assembly capable of detecting certain physical or chemical properties and / or material characteristics in its surroundings "qualitatively" or quantitatively as "measurands". These quantities are detected using physical or chemical effects and converted into analog or digital electrical signals. Such signals are also called "sensor signals".

[0016] In particular, the sensor signal is proportional to the power consumption, in particular the power consumption of the test winding and / or the first main winding and / or the second main winding. In particular, the sensor signal, in particular the sensor signal of the test winding and / or the first main winding and / or the second main winding, can be converted into the power consumption using mathematical rules.

[0017] By "power dissipation" is understood the intensity of the current flowing through the circuit, in particular the test winding and / or the first main winding and / or the second main winding, at a defined voltage. It should be clearly noted that the term power dissipation does not require information about the sign of the current. In particular, the power dissipation can correspond to a positive or negative current.

[0018] The sensor signal is preferably understood to mean the power consumption of the first main winding. In particular, the power consumption of the first main winding can be converted into a residual current of one of the circuits monitored by the sensor using a mathematical rule. In particular, this mathematical rule can be determined by a calibration curve of the sensor.

[0019] By "residual current" is understood the vector sum of the currents of all the electrical conductors around which the sensor is arranged.

[0020] The residual current may have an AC component and / or a DC component.

[0021] By "bi-current sensitively determining" the residual current, it is understood that the sensor is set up so that it can determine both the AC component and the DC component.

[0022] By "magnetic field sensitive element" is understood an element which reacts to a magnetic field by a change in at least one state quantity of the element.

[0023] In particular, a magnetic field sensitive element is understood to be a material that has magnetic properties.

[0024] A magnetic field sensitive element is particularly preferably understood to be a soft magnetic material.

[0025] By "soft magnetic material" is understood a material that can be easily magnetized in a magnetic field. In particular, soft magnetic materials have a coercive force of 1,000 A / m or less.

[0026] By "coercive force" is understood the magnetic field strength required to completely demagnetize a magnetic field sensitive element before it is charged to saturation magnetic flux density.

[0027] In particular, soft magnetic materials are understood to be materials made from amorphous metals and having a nanocrystalline structure.

[0028] In particular, the soft magnetic material comprises an alloy containing iron, nickel and cobalt.

[0029] By "winding" is understood a turn of electrically conductive material in a solid aggregate, especially in the form of a wire, which extends around a magnetic field sensitive element.

[0030] By "main winding" is understood a winding that is actively supplied with current by a current source. Alternatively, the main winding can be connected to a voltage source. The main winding can also be called the "first main winding."

[0031] In particular, the main winding, in particular the first main winding, is configured to provide the sensor signal indirectly, in particular via the power consumption of the main winding, in particular via the power consumption of the first main winding and / or the second main winding.

[0032] In particular, from the power consumption of the main windings, in particular the first and / or second main windings, the residual current of a circuit designated and monitored by a sensor can be determined using mathematical rules, in particular mathematical rules that can be derived from the calibration of the sensor.

[0033] By "test winding" is meant a winding that is configured as a purely passive element so that a current flows through it as a result of the inductive action of the magnetic field sensitive element. The test winding can be configured in particular to provide a test winding signal that can be used within the scope of the sensor calibration. In particular, the test winding has a different number of turns compared to the main winding.

[0034] In particular, the calibration of the sensor is carried out before the start of the actual measurement operation whenever a measurement operation is initiated.

[0035] By "shield" is understood an element arranged to direct electric and / or magnetic fields away from a magnetic field sensitive element and / or to protect the surroundings of the sensor from the electric and / or magnetic fields emanating from the sensor.

[0036] In particular, the shield is made of an alloy containing 20% ​​by weight or more of nickel, preferably 30% by weight or more of nickel, and particularly preferably 50% by weight or more of nickel, and more preferably 60% by weight or more of nickel, more preferably 70% by weight or more of nickel, and particularly preferably 80% by weight or more of nickel.

[0037] In particular, the shield is made of an alloy containing 0.5% by weight or more of molybdenum, preferably 1% by weight or more of molybdenum, and particularly preferably 3% by weight or more of molybdenum, and more preferably 4% by weight or more of molybdenum, more preferably 5% by weight or more of molybdenum, and particularly preferably 5.5% by weight or more of molybdenum.

[0038] In particular, the shielding body is made of an alloy having at least 10% by weight of iron, preferably at least 20% by weight of iron, particularly preferably at least 30% by weight of iron, and even more preferably at least 40% by weight of iron, more preferably at least 50% by weight of iron, particularly preferably at least 55% by weight of iron.

[0039] It is expressly pointed out that the above values ​​for the alloy composition of the shield should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the magnitude of the alloy composition of the shield proposed herein.

[0040] In particular, the shield is of multi-part, in particular two-part, design.

[0041] Particularly preferably, the two-part shield is formed in such a way that the two shield parts overlap or at least partially overlap one another at the outer shield wall.

[0042] Furthermore, it is particularly preferred that the two-part shield is formed so that the two shield parts do not come into contact with each other on the inner wall of the shield, and the two shield parts of the two-part shield preferably form a gap on the inner wall of the shield.

[0043] By "through opening" is understood a free cross section formed in the interior region of the magnetic field sensitive element.

[0044] Particularly preferably, the outer contour of the magnetic field sensitive element is designed as an oval, and the inner contour of the magnetic field sensitive element is also formed as an oval with two axes of symmetry.

[0045] The inner contour of the magnetic field sensitive element defines a through opening for the magnetic field sensitive element.

[0046] In particular, the material thickness of the magnetic field sensitive element is approximately constant or constant. In the special case where the magnetic field sensitive element has a circular cross section and the material thickness of the magnetic field sensitive element is constant, the magnetic field sensitive element has a geometric shape of a circular ring cross section.

[0047] An "oval" is a flat, rounded, convex outline. Ovals include the circle and the ellipse as special cases, but unlike these, an oval need not have an "axis of symmetry". In particular, an oval is a closed, convex curve in the plane that is twice continuously differentiable.

[0048] An oval has an axis of symmetry if its curves are mirrored on either side of an imaginary line. An oval has two axes of symmetry if its curves are mirrored on either side of two non-coincident imaginary lines. In particular, a circle and an ellipse are each ovals with two axes of symmetry.

[0049] By "winding" is understood the turn of a winding around the magnetic field sensitive element.

[0050] The "accommodation space" is defined by the shielding inside the shielding and is configured to accommodate other elements, in particular the magnetic field sensitive element, the first main winding, and the test winding, as well as the second main winding, insulators, and spacer rings.

[0051] "Radial" is understood to mean a direction extending from a central axis of the sensor that extends normal to the smallest possible cross-sectional area of ​​the through opening, in a straight line radial to the central axis.

[0052] By "shield outer wall" is understood the radially outer surface formed by the shield, in particular by a two-part shield fitted together.

[0053] "Inner wall of the shielding body" is understood to mean the radially inner surface formed by the shielding body, in particular by a projection surface, with any partial surfaces of the shielding body located inside and a circumferentially extending gap.

[0054] By "circumferentially extending gaps" is meant gaps which extend in the circumferential direction in the inner wall of the shielding between the partial surfaces of the inner wall of the shielding formed by the shielding. A circumferentially extending gap opens the shielding in the direction of the receiving space of the shielding when viewed in the radial direction and from the central axis.

[0055] By "electrical conductor" is meant any medium that has mobile charge carriers and is therefore capable of transporting electric charges. In particular, electrical conductors are understood to mean copper and / or aluminum cables as conductors through which electrons can move.

[0056] By "internal width" along the axis of symmetry of a through opening is understood the extension of the through opening in the direction and height of the observed axis of symmetry.

[0057] If the ellipse forming the through opening of the magnetic field sensitive element in cross section has two axes of symmetry with different extensions along the axes of symmetry, a first inner width occurs along the first axis and a second inner width occurs along the second axis of symmetry.

[0058] When the mere reference is made in this document to the inner width, this refers in particular to the inner width along the axis of symmetry having the greater extension.

[0059] By "limiting current" is understood a residual current that the sensor can detect with sufficient accuracy and speed so that the protective circuit breaker can interrupt the voltage in the circuit monitored by the sensor as soon as the sensor detects a residual current that at least reaches or exceeds the limiting current of the protective circuit breaker.

[0060] The smaller the limiting current of the protective circuit breaker, and therefore directly also the measurement suitability of the small residual current of the sensor, and the faster this is reliably recognized by the sensor, the less danger can arise from residual currents occurring.

[0061] Sensors are known in the prior art that have smaller inner widths of the through apertures of the magnetic field sensitive elements than those proposed here.

[0062] In particular, prior art efforts have been made to reduce the inner width of the through openings of the magnetic field sensitive elements.

[0063] The motivation for this effort is that the desire to make residual currents smaller and more quickly detectable necessitates placing magnetic field sensitive elements as close as possible to the live electrical conductors of the monitored circuit.

[0064] The strength of the magnetic field emanating from a live electrical conductor decreases inversely with the distance from the live electrical conductor, so the further a magnetic field sensitive element is from the live electrical conductor of the monitored circuit, the lower the magnetic flux density in the magnetic field sensitive element caused by the magnetic field strength around the live electrical conductor.

[0065] Additionally, the magnetic field strengths of at least two current-carrying electrical conductors in the monitored circuit, both of which must be passed through the through opening of the magnetic field-sensitive element in order to monitor residual current and which have opposite current flow directions, are superimposed and ideally cancel each other out, as long as no residual current occurs in the monitored current circuit.

[0066] This results in a particularly low magnetic field strength acting on the magnetic field sensitive element, particularly when the residual current in the monitored circuit is small, which in turn results in a particularly low magnetic flux density in the magnetic field sensitive element.

[0067] The lower the magnetic flux density in the magnetic field sensitive element, the lower the current that the magnetic flux density in the magnetic field sensitive element will induce in the test winding and / or the first main winding and / or the second main winding.

[0068] In other words, the larger the inner width of the through opening of the magnetic field sensitive element, the greater the distance of the electrical conductor of the monitored circuit from the magnetic field sensitive element can be, so that small residual currents cannot be detected at all or can only be detected with particular difficulty.

[0069] For this reason, the need to be able to detect relatively small residual currents leads to technical efforts to make the inner width of the through opening of the magnetic field sensitive element as small as possible.

[0070] Making the magnetic field sensitive element as small as possible also reduces the weight of the sensor, reduces the material required, and therefore reduces cost and space requirements.

[0071] Thus, many factors favor a smaller inner width for the through opening of the magnetic field sensitive element.

[0072] It is known in the prior art that protective circuit breakers with very small residual currents tend to malfunction when the monitored circuit is turned on.

[0073] The reason is that when a circuit is switched on, sensors known in the prior art generate a sensor signal that can be interpreted as a residual current, even though there should be no residual current in the monitored circuit. The demand for low residual current means an increased number of false trips of protective circuit breakers.

[0074] However, contrary to conventional wisdom, it was unexpectedly discovered through laboratory experiments that there is an optimal range of the inner width of the through opening of the magnetic field sensitive element that can detect the smallest possible residual current within a sufficient time while at the same time significantly reducing the possibility of false activation of the protective circuit breaker connected to the sensor, and that this discovered range requires an inner width of the through opening of the magnetic field sensitive element that is larger than previously known in the prior art.

[0075] In other words, a range of inner widths of the through opening has been discovered that allows for the robust determination of the smallest possible residual current, so that when the circuit monitored by the sensor is turned on, no sensor signal exceeding the required limit current, which can be interpreted as a residual current, occurs, or occurs only very rarely.

[0076] In order to achieve the smallest limiting current in the monitored circuit that can be robustly determined by the sensor, it is proposed that the inner width of the through opening of the magnetic field sensitive element be in the range of 25.2 to 32 mm.

[0077] Preferably, it is proposed that the inner width of the through opening of the magnetic field sensitive element is in the range of 25.5 mm to 29 mm.

[0078] It is particularly preferred that the inner width of the through opening of the magnetic field sensitive element is in the range of 25.8 mm to 27 mm.

[0079] It should be clearly pointed out that the above values ​​of the inner width of the through opening of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the present invention. In short, these values ​​should provide an indication of the size of the inner width of the through opening of the magnetic field sensitive element proposed herein.

[0080] Of course, any combination of the recited range limits for the inner widths may be used.

[0081] When a voltage supply is switched on in a monitored circuit, a physical operative connection is established between the magnetic field prevailing around an electrical conductor and the magnetic flux density in operative relation thereto.

[0082] This results in a brief, time-varying pulse of magnetic flux in the magnetic field sensitive element that is primarily location dependent when turned on.

[0083] This primarily results in oscillatory behavior of the magnetic flux in the magnetic field sensitive element.

[0084] This short-term oscillatory behavior in the magnetic field sensitive element also briefly causes a passed current to flow in the test winding and / or the first main winding and / or the second main winding, which are in a operative relationship with the magnetic field sensitive element via induction.

[0085] Laboratory experiments have shown that this can briefly result in a sensor signal that can be interpreted as a residual current, which can exceed a predetermined limit current during the designated operation of the sensor in the protective circuit breaker, which can cause the protective circuit breaker to shut down when the voltage supply of the monitored circuit is switched on.

[0086] Several different factors have a damping effect on this short-term vibration behavior, some of which cannot be influenced by design measures.

[0087] In laboratory experiments, it has been discovered that one of these factors is determined by the spacing between the electrical conductors to be monitored by the proposed sensor: the greater the distance or spacing, the stronger the dynamic interaction between the electrical conductors and the sensor signal when the voltage supply is turned on.

[0088] Safety concerns regarding the spacing of electrical conductors in the cross section of the through opening of the magnetic field sensitive element require ever greater spacing to avoid short circuits between the electrical conductors, which amplifies this factor and increases the likelihood of generating an unwanted sensor signal when the circuit is turned on.

[0089] Another factor, also confirmed in laboratory experiments, is related to the ratio of the distance between the first and second electrical conductors to a point on the magnetic field-sensitive element. The further this ratio is from 1, the greater the short-term regional differences in magnetic flux density on the magnetic field-sensitive element. The greater these regional differences, the stronger the amplification of the sensor's dynamic start-up behavior when the circuit is switched on.

[0090] By increasing the inner width of the through opening of the magnetically sensitive element, the ratio of the distance between the first electrical conductor and the different electrical conductor to a point in the magnetic field sensitive element can be brought closer to the value 1, thereby advantageously achieving a damping effect on the sensor behavior due to the above-mentioned switch-on effect.

[0091] Since increasing the inner width of the magnetic field sensitive element results in a decrease in sensitivity, especially to small residual currents, an optimal range for the inner width of the through opening of the magnetic field sensitive element is proposed, taking into account two physical effects, so that on the one hand the minimum residual current during normal operation of the sensor can be detected within a sufficient time, and on the other hand when the power grid monitored by the sensor is turned on, no sensor signal is generated that conveys a false detection of a non-existent residual current.

[0092] In particular, it is proposed here to configure the sensor so that it can be placed around all conductors of the circuit that introduce and extract current into and from the monitored circuit during normal operation, and in particular not around protective conductors.

[0093] In particular, it is proposed that the proposed sensor be placed around the outer conductor and the neutral conductor in its intended use in a single-phase power supply network, so that the sensor is placed around two electrical conductors in the single-phase power supply network.

[0094] Furthermore, for specified use in a three-phase power supply network, it is proposed to arrange the sensor around the three outer conductors and the neutral conductor, thus resulting in a total of four electrical conductors in the three-phase power supply network.

[0095] In particular, it is proposed that the through opening of the magnetic field sensitive element is circular in cross section, ie an oval with two semi-radii of equal length.

[0096] Furthermore, it is proposed in particular that the through opening of the magnetic field sensitive element has an elliptical cross section, ie an oval with two semi-radii of different lengths.

[0097] It is expressly pointed out that the feature that the through opening of the magnetic field sensitive element is shaped as an oval in cross section with two axes of symmetry is not essential in the sense of the invention.

[0098] Rather, other geometries of the magnetic field-sensitive element are also conceivable here, which in particular allow a good compromise with regard to the above-mentioned physical effects, in particular these geometries are also based on an oval cross section.

[0099] Depending on the geometry of the magnetic field-sensitive element, it is proposed that the geometry of the shield is also adapted accordingly.

[0100] In particular, it is also proposed here that the magnetic field sensitive element has a high magnetic permeability.

[0101] The "permeability" of a magnetic field sensitive element is understood to be the magnetization of the material in an external magnetic field. The higher the permeability of the magnetic field sensitive element, the greater the ratio of the magnetic flux density in the magnetic field sensitive element to the magnetic field strength acting on the magnetic field sensitive element.

[0102] A magnetic field sensitive element having a high magnetic permeability results in a relatively high magnetic flux density being present in the magnetic field sensitive element even when the magnetic field strength is low, and therefore the high magnetic permeability of the magnetic field sensitive element increases the sensitivity of the sensor, thereby helping the sensor to detect even small residual currents.

[0103] In particular, it is proposed that the magnetic field sensitive element has a magnetic permeability of 35,000 H / m (Henry per meter) or more, preferably a magnetic permeability of 45,000 H / m or more, particularly preferably a magnetic permeability of 50,000 H / m or more, more preferably a magnetic permeability of 60,000 H / m or more, preferably a magnetic permeability of 70,000 H / m or more, particularly preferably a magnetic permeability of 80,000 H / m or more, more preferably a magnetic permeability of 90,000 H / m or more, preferably a magnetic permeability of 100,000 H / m or more, particularly preferably a magnetic permeability of 110,000 H / m or more. More preferably, the magnetic field sensitive element has a magnetic permeability of 120,000 H / m or more, preferably 130,000 H / m or more, and particularly preferably 140,000 H / m or more. In particular, the magnetic field sensitive element preferably has a magnetic permeability of 150,000 H / m or more.

[0104] The above permeability values ​​apply when the magnetic field oscillates at 50 Hz.

[0105] It is to be clearly pointed out that the above values ​​of the magnetic permeability of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen below on an engineering scale without departing from the described aspects of the present invention. In short, these values ​​should provide an indication of the magnitude of the magnetic permeability of the magnetic field sensitive element proposed herein.

[0106] In particular, the magnetic field sensitive element has a magnetic saturation flux density of 1 T or more, preferably, the magnetic field sensitive element has a magnetic saturation flux density of 1.1 T or more, and particularly preferably, the magnetic field sensitive element has a magnetic saturation flux density of 1.2 T or more. In particular, the magnetic field sensitive element has a magnetic saturation flux density of 1.3 T or more.

[0107] It is to be clearly pointed out that the above values ​​of the magnetic saturation flux density of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen below on an engineering scale without departing from the described aspects of the present invention. In simple terms, the values ​​should provide an indication of the magnitude of the magnetic saturation flux density of the magnetic field sensitive element proposed herein.

[0108] In particular, it is proposed here that the magnetic field sensitive element has a high degree of linearity with respect to magnetic permeability, and in particular has a higher linearity with respect to magnetic permeability than ferrite material.In other words, it is proposed in particular not to use ferrite material for the magnetic field sensitive element.

[0109] The more linear the magnetic field sensitive element is with respect to the magnetic permeability, the higher the achievable measurement accuracy of the sensor.

[0110] In particular, the magnetic field sensitive element has a coercive force of 30 mA / cm or less, preferably a coercive force of 20 mA / cm or less, and particularly preferably a coercive force of 15 mA / Acm or less. Even more preferably, the magnetic field sensitive element has a coercive force of 10 mA / cm or less, preferably a coercive force of 5 mA / cm or less, and particularly preferably a coercive force of 2 mA / cm or less. Even more preferably, the magnetic field sensitive element has a coercive force of 1 mA / cm or less, preferably a coercive force of 0.5 mA / cm or less, and particularly preferably a coercive force of 0.2 mA / cm or less. In particular, the magnetic field sensitive element preferably has a coercive force of 0.1 mA / cm or less.

[0111] The coercivity values ​​given above apply when the magnetic field oscillates at 50 Hz.

[0112] A particularly high measurement accuracy can be achieved due to the low coercivity of the magnetically sensitive element, especially when the field strength of the magnetic field changes: the lower the coercivity of the magnetically sensitive element, the higher the measurement accuracy of the sensor.

[0113] It is to be clearly pointed out that the above values ​​of the coercivity of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen below on an engineering scale without departing from the described aspects of the present invention. In short, the values ​​should provide an indication of the magnitude of the coercivity of the magnetic field sensitive element proposed herein.

[0114] In particular, it is proposed to select or manufacture the magnetic field sensitive element from a soft magnetic material.

[0115] In particular, the magnetic field sensitive element is made of an alloy having 70% by weight or more of iron, preferably 71.5% by weight or more of iron, particularly preferably 73% by weight or more of iron. In particular, the magnetic field sensitive element is made of an alloy having 73.5% by weight or more of iron.

[0116] In particular, the magnetic field sensitive element is made of an alloy containing 0.75 to 1.25% by weight of copper, preferably 0.85 to 1.15% by weight of copper, particularly preferably 0.95 to 1.05% by weight of copper. In particular, the alloy of the magnetic field sensitive element contains 1% by weight of copper.

[0117] In particular, the magnetic field sensitive element is made of an alloy containing 2 to 4% by weight of niobium, preferably 2.5 to 3.5% by weight of niobium, particularly preferably 2.8 to 3.2% by weight of niobium. In particular, the alloy of the magnetic field sensitive element contains 3% by weight of niobium.

[0118] In particular, the magnetic field sensitive element consists of an alloy containing 5 to 9% by weight of boron, preferably 6 to 8% by weight of boron, particularly preferably 6.5 to 7.5% by weight of boron. In particular, the alloy of the magnetic field sensitive element has a proportion of boron of 7% by weight.

[0119] In particular, the magnetic field sensitive element is made of an alloy containing 14 to 17% by weight of silicon, preferably 15 to 16% by weight of silicon, particularly preferably 15.4 to 15.6% by weight of silicon. In particular, the alloy of the magnetic field sensitive element has a silicon content of 15.5% by weight.

[0120] It is expressly pointed out that the above values ​​of the alloy composition of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention.

[0121] In particular, the magnetic field sensitive element preferably consists of a nanocrystalline soft magnetic material having a typical grain size in the range of 5 to 30 gm, preferably of a nanocrystalline soft magnetic material having a typical grain size in the range of 7 to 20 gm, more preferably of a nanocrystalline soft magnetic material having a typical grain size in the range of 8 to 15 gm.

[0122] In particular, the magnetic field sensitive element is produced from a strip having a particularly small strip thickness, since, according to Maxwell's equations, in this way eddy current losses in the magnetic sensitive element can be kept low.

[0123] In particular, the magnetic field sensitive element has a band thickness in the range of 5 to 50 gm, preferably in the range of 7.5 to 40 gm, particularly preferably in the range of 10 to 30 gm.

[0124] It should be clearly noted that the above values ​​of the band thickness of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the present invention. In short, the values ​​should provide an indication of the size of the band thickness of the magnetic field sensitive element proposed here.

[0125] In particular, the cross-sectional area of ​​the iron of the magnetic field sensitive element is 0.03 to 0.15 cm 2 Furthermore, the cross-sectional area of ​​the iron of the magnetic field sensitive element is preferably in the range of 0.04 to 0.12 cm 2 Particularly preferably, the cross-sectional area of ​​the iron of the magnetic field sensitive element is in the range of 0.05 to 0.1 cm 2 The range is.

[0126] In particular, the magnetic field sensitive element has a height of 3 to 7 mm, preferably the magnetic field sensitive element has a height of 3.4 to 6.6 mm, particularly preferably the magnetic field sensitive element has a height of 3.8 to 6.2 mm.

[0127] It is expressly pointed out that the above values ​​of the cross-sectional area of ​​the iron and the height of the magnetic field sensitive element should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the size of the cross-sectional area of ​​the iron and the height of the magnetic field sensitive element proposed herein.

[0128] In particular, it is proposed that the sensor determines the residual current according to the operating principle of a Förster probe.

[0129] In particular, the turns of the first main winding are equally spaced around the entire circumference of the magnetic field sensitive element.

[0130] In particular, the first main winding has a number of turns in the range of 25 to 150, preferably in the range of 35 to 135, and particularly preferably in the range of 40 to 130. Furthermore, in particular, the first main winding has a number of turns in the range of 45 to 125, preferably in the range of 50 to 120, and particularly preferably in the range of 60 to 110.

[0131] Advantageously, in order to generate as locally uniform a magnetic flux density as possible in the magnetic field sensitive element when the first main winding is energized, the number of turns of the first main winding proposed here makes it possible to achieve that the magnetic field sensitive element can be wound with as equal a distance as possible between the individual windings.

[0132] It is expressly pointed out that the above values ​​for the number of turns of the first main winding should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention. In simple terms, these values ​​should provide an indication of the magnitude of the number of turns of the first main winding proposed herein.

[0133] In particular, the turns of the test winding are evenly spaced around the entire circumference of the magnetic field sensitive element.

[0134] In particular, the test winding has a number of turns in the range of 3 to 40, preferably in the range of 4 to 35, and particularly preferably in the range of 5 to 30. Furthermore, in particular, the test winding has a number of turns in the range of 6 to 25, preferably in the range of 8 to 22, and particularly preferably in the range of 10 to 18.

[0135] Advantageously, in particular since the test windings can be arranged uniformly over the magnetic field sensitive element with equal spacing between adjacent windings, the number of turns of the test winding proposed here makes it possible to achieve a particularly accurate determination of the magnetic flux density of the magnetic field sensitive element by virtue of the inductive effect this causes in the test winding.

[0136] It is expressly pointed out that the above values ​​for the number of turns of the test windings should not be understood as strict ranges, but rather should be able to be exceeded or exceeded on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the magnitude of the number of turns of the test windings proposed herein.

[0137] The range of the through openings of the magnetic field sensitive elements proposed here, when the shield is ideally designed for function, results in an inner dimension of the through openings of the shield in the range of 18.2 to 30 mm, preferably in the range of 19.5 to 27.5 mm, particularly preferably in the range of 20.5 to 24.2 mm, and particularly preferably in the range of 20.8 mm to 22.2 mm.

[0138] It is expressly pointed out that the above values ​​for the range of the internal dimensions of the through openings of the shield should not be understood as strict ranges, but rather should be able to be exceeded or exceeded on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the size of the respective proposed ranges of the internal dimensions of the through openings of the shield.

[0139] Of course, the range limits set forth for the internal dimensions can be combined with one another in any manner.

[0140] According to a preferred embodiment, the magnetically sensitive element is covered by an insulator, and the insulator is arranged between the magnetically sensitive element and the first main winding and between the magnetically sensitive element and the test winding.

[0141] In this regard, the following terminology is mentioned: By "insulator" is understood an element made of a material with particularly low electrical conductivity and therefore conducting very little current compared to the material surrounding it.

[0142] In particular, the insulator is formed in two parts, so that it can be opened to accommodate the magnetic field sensitive element and then closed again.

[0143] The two-part insulator has a positive and / or a force connection between the two parts of the insulator, which advantageously allows it to reliably surround the magnetic field sensitive element and not unintentionally open and / or release the magnetic field sensitive element again.

[0144] In particular, the insulator preferably has a lower hardness than the material of the winding, so that any friction that may occur between the insulator and the winding advantageously damages the insulator rather than the winding.

[0145] The insulator advantageously allows for regional isolation of the magnetic field sensitive element from the first main winding and the test winding, and possibly the second main winding, thereby reducing possible damage to the windings.

[0146] If the insulator has a low hardness and / or a low modulus of elasticity as the material of the windings of the first main winding and the test winding, and possibly the second main winding, a preload can be set on the windings, which will result in an elastic deformation of the insulator and thus a positive connection between the insulator and the windings, and will better fix the windings relative to one another, thereby advantageously increasing the reliability of the sensor.

[0147] Furthermore, the insulator allows the distance between the winding and the magnetic field sensitive element to be always constant, which advantageously ensures that the physical operational connection between the winding and the magnetic field sensitive element remains constant, and therefore advantageously ensures that the accuracy of the sensor signal determination is permanently maintained.

[0148] Preferably, the sensor has a second main winding, the second main winding surrounding the magnetically sensitive element and / or the insulator with multiple windings.

[0149] In this regard, the following terminology is mentioned: By "second main winding" is understood a main winding that is wound around the magnetic field sensitive element in addition to the first main winding.

[0150] In particular, the second main winding has a winding direction that is different from the winding direction of the first main winding.

[0151] In the specified operation of a sensor according to the first aspect of the invention having a first main winding and no second main winding, an alternating voltage is supplied to the first main winding, so that each time the sign of the supply voltage changes, the current flow in the first main winding reverses sign.

[0152] Alternatively, the first main winding may be supplied with a current source that alternates between opposite current directions. Advantageously, the use of a current source can achieve higher measurement accuracy of the sensor.

[0153] In other words, the first main winding has current flowing in periodically different directions during the designated operation of the sensor.

[0154] The time profile of current flow in the first main winding during a specified sensor operation can have a sinusoidal or rectangular shape, or other oscillatory shape.

[0155] An oscillating current flow in the first main winding is configured to induce a similarly oscillating magnetic flux density in the magnetic field sensitive element.

[0156] The sensor proposed here has two main windings, namely a first main winding and a second main winding.

[0157] Preferably, the number of turns of the second main winding is equal to the number of turns of the first main winding.

[0158] This allows the single main winding to not have to change sign of current flow direction in order for the sensor to operate as specified. Rather, each of the two main windings can be operated in a pulsed manner so that they alternate between having current flow and not having current flow.

[0159] When two main windings are wound around the magnetic field sensitive element in different directions of rotation, the two main windings can be alternately connected to the same voltage or current source, allowing the voltage or current source to have a steady, constant output value, thereby inducing an alternating magnetic flux density in the magnetic field sensitive element. This advantageously allows for a more optimal design of the operating circuit for a specified sensor operation. This reduces the common costs of the sensor and the operating circuit, even if an additional main winding is required.

[0160] In particular, the turns of the second main winding are equally spaced around the entire circumference of the magnetic field sensitive element.

[0161] In particular, the second main winding has a number of turns in the range of 25 to 150, preferably in the range of 35 to 135, and particularly preferably in the range of 40 to 130. Furthermore, in particular, the second main winding has a number of turns in the range of 45 to 125, preferably in the range of 50 to 120, and particularly preferably in the range of 60 to 110.

[0162] Advantageously, the number of turns of the second main winding proposed herein makes it possible to achieve winding around the magnetic field sensitive element with as equal a distance between the individual windings as possible, so that when current is applied to the second main winding, a magnetic flux density that is as locally uniform as possible in the magnetic field sensitive element is generated.

[0163] It is expressly pointed out that the above values ​​for the number of turns of the second main winding should not be understood as strict ranges, but should be able to be exceeded or exceeded on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the magnitude of the number of turns of the second main winding proposed herein.

[0164] According to a particularly expedient embodiment, the sensor comprises a spacer ring, which is arranged between the inner wall of the shield and the first main winding.

[0165] In this regard, the following terminology is mentioned: By "spacer ring" is understood a ring-shaped element arranged to be placed between the inner wall of the shield and the first main winding of the sensor.

[0166] In particular, the spacer ring is configured to reduce or fill the radial gap in the receiving space between the shield inner wall and the main winding.

[0167] In particular, the spacer ring is configured to fill the axial gap between the first shielding part and the second shielding part, so that as soon as the two shielding parts are each placed against the spacer ring, the spacer ring can define the width of the circumferential gap.

[0168] In particular, the spacer ring is made of plastic or another material with a relatively low specific conductivity.

[0169] The spacer ring can advantageously also protect the wires of the main winding and / or test winding during assembly of the sensor. The spacer ring, together with the magnetic field-sensitive element already wound with the main winding or windings and test winding, can be inserted into the first part of the shield, particularly into a designated portion of the shield that overlaps at least partially with another part of the shield on its outer surface. Thus, the magnetic field-sensitive element can be carefully inserted into the first part of the shield under visual supervision, with the magnetic field-sensitive element and, in particular, the windings arranged around the magnetic field-sensitive element being protected from mechanical loads by the spacer ring on the inside. The second part of the shield can then be attached so that the windings are already protected from mechanical loads by the spacer ring and the overlapping first part of the shield. In this way, the spacer ring can advantageously improve the mechanical protection of sensitive components, even when visual access to the sensitive components is not possible during assembly of the second part of the shield.

[0170] Preferably, a spacer ring is proposed here which has an insert inside its base made of a material with a relatively high magnetic permeability, in particular a permeability that substantially corresponds to the magnetic permeability of the shield, in particular the insert being completely surrounded by the base of the spacer ring so that it is insulated by the base, which has a relatively low electrical conductivity.

[0171] This advantageously achieves that the leakage of the magnetic field generated from the magnetic field sensitive element in the circumferentially extending gap during the specified operation of the sensor can be reduced as a result of the high magnetic permeability of the spacer ring, thereby advantageously increasing the measurement accuracy of the sensor and also reducing the energy consumption of the sensor.

[0172] Optionally, the shield has a coating, in particular an electrically insulating coating.

[0173] In this regard, the following terminology is mentioned: By "coating" is understood an adherent layer of amorphous material on the surface of the shield.

[0174] In particular, the coating is designed so that it conducts electrical current particularly poorly, and therefore has a particularly low electrical conductivity.

[0175] In particular, the coating preferably consists of an epoxy resin.

[0176] In particular, the coating is provided on the shield so as to cover at least a partial surface of the outer shield surface that is designated to be located near the printed circuit board.

[0177] Advantageously, in this manner, isolation of the shield relative to the designated circuit board can be achieved, thereby advantageously preventing short circuits between the shield and the designated circuit board.

[0178] According to an expedient embodiment, the shield has a material thickness in the range of 0.25 mm to 0.45 mm, preferably in the range of 0.3 mm to 0.4 mm, particularly preferably in the range of 0.32 mm to 0.38 mm.

[0179] In this regard, the following terminology is mentioned: "Material thickness" or material thickness is understood as the extent of an object in the direction of a surface normal.

[0180] "Eddy currents" are understood to be currents induced in an electrical conductor expanding in a time-varying magnetic field and / or moving in a time-constant but spatially inhomogeneous magnetic field. If the conductor has a finite electrical resistance, it will heat up as a result of the eddy currents. The amount of energy converted into heat is called "eddy current losses."

[0181] It is now proposed to reduce the material thickness of the shielding of the magnetic field sensitive element together with at least one main winding and a test winding around the magnetic field sensitive element.

[0182] The possibility of reducing the material thickness in the region of the shield is based on innovations in the field of shield manufacturing.

[0183] In particular, the shield is deep-drawn or injection-molded.

[0184] This advantageously allows cost savings to be achieved compared to a larger shielding material thickness.

[0185] During the specified operation of the sensor, the magnetic field sensitive element has an oscillating magnetic flux density. Since the shield is also made of a material with good electrical conductivity, the change in magnetic flux density of the magnetic field sensitive element will have an inductive effect on the shield. This inductive effect is undesirable because it will cause eddy current losses.

[0186] Reducing the material thickness of the shield can advantageously reduce eddy current losses that occur during designated operation of the sensor.

[0187] This can advantageously reduce the energy consumption of the sensor and increase the measurement accuracy of the sensor.

[0188] It is expressly pointed out that the above values ​​of the shielding material thickness should not be understood as strict ranges, but rather should be able to be exceeded or exceeded on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the magnitude of the shielding material thickness proposed herein.

[0189] Preferably, the gap extending in the circumferential direction has a gap width in the range of 0.1 mm to 2.0 mm, more preferably in the range of 0.3 mm to 1.7 mm, and particularly preferably in the range of 0.6 mm to 1.3 mm.

[0190] In this regard, the following terminology is mentioned: By "gap width" is meant the width of the gap, in particular the width of the gap extending in the circumferential direction on the inner wall of the shielding body.

[0191] The circumferentially extending gaps in the shield are particularly advantageous because the shield would otherwise also be a winding of a highly electrically conductive material around the magnetic field sensitive element, on which a relatively strong inductive effect would be exerted during the designated operation of the sensor, when the magnetic flux density oscillates in the magnetic field sensitive element, which would increase eddy current losses associated with the shield, which could lead to an increase in the energy consumption of the sensor and a decrease in the measurement accuracy of the sensor.

[0192] However, the circumferential gaps in the sensor shield also result in a reduction of the magnetic field around the magnetic field sensitive element, especially since the magnetic permeability of air within the circumferential gaps is much lower than the magnetic permeability of the shield.

[0193] Therefore, if the width of the circumferential gap is too large, various kinds of physical effects will occur, which in turn will have a negative effect on the energy consumption of the sensor and on the measurement accuracy of the sensor.

[0194] Therefore, a specific range of gap width of the circumferentially extending gap is proposed here, which advantageously makes it possible to achieve an optimum between the measurement accuracy of the sensor's optimal sensitivity when the circumferentially extending gap width is too small and when the circumferentially extending gap width is too large, based on different physical effects.

[0195] Furthermore, it can be achieved that the width of the circumferential gap proposed here allows for an advantageous minimization of the energy consumption for the operation of the sensor.

[0196] It is expressly pointed out that the above values ​​of the gap width of the circumferentially extending gap should not be understood as strict limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the size of the gap width of the circumferentially extending gap proposed herein.

[0197] According to an expedient embodiment, the sensor comprises an electrical connector, which comprises a support plate, a connector neck and a plurality of electrical contacts. the electrical connector has at least two electrical contacts per winding; the electrical contacts are arranged radially outside the outer wall of the shield; the support plate is disposed between the shield outer wall and the first main winding; a connector neck extending through the opening in the outer wall of the shield and connecting the support plate and the electrical contacts to each other; The support plate and the connector neck each have a corresponding cavity configured to receive two electrical wires in operative connection with each winding from the receiving space and pass them from the receiving space through the openings in the shield to the electrical contacts. The cavity has a notch parallel to the outer wall of the shield, through which an electric wire can be inserted into the central region of the cavity.

[0198] In this regard, the following terminology is mentioned: By "electrical connector" is understood an element that is intended to be attached to a sensor and that has at least the necessary number of accessible electrical contacts.

[0199] In particular, the connector makes it possible to electrically connect the electrical and / or electronic components of the sensor with the electrical contacts of the connector, which are relatively easily accessible.

[0200] In particular, the connector preferably allows, at least indirectly, the electrical contacts to be arranged in a fixed position relative to the sensor.

[0201] Overall, the connector therefore particularly and advantageously enables the sensor to be used with a fixed relative positioning between the magnetic field sensitive element and the electrical contacts, and the electronic and / or electrical elements of the sensor can be electrically connected to the electrical contacts already during the manufacture of the sensor.

[0202] Therefore, the sensor can be advantageously connected to the substrate directly by soldering or indirectly via the electrical contacts of the electrical connector by other contact elements, in particular a plug, such that the relative position of the magnetic field sensitive element to the substrate can be fixed by the connection made possible at least indirectly by the electrical connector.

[0203] In particular, electrical connectors have a plastic as a substrate, especially a plastic with a relatively low electrical conductivity.

[0204] In particular, the electrical contacts of the electrical connector are at least partially surrounded by the substrate of the connector, so that there is a force-locking and / or form-locking connection between the substrate and the electrical contacts. Furthermore, in particular, the electrical contacts are arranged spatially separated from one another by the substrate of the electrical connector, so that advantageously there is no direct electrical contact between two electrical contacts, thereby preventing short circuits between individual electrical and / or electronic elements of the sensor.

[0205] By "support plate" is understood an area of ​​the electrical connector which is arranged to provide at least an indirect connection between the magnetic field sensitive element and the electrical connector in a form-locking and / or force-locking manner.

[0206] In particular, the support plate can be accommodated in the accommodation space of the shield, in particular between the shield and the main winding, in particular between the main winding and the outer shield wall of the shield.

[0207] In particular, the support plate is preferably configured to be inserted into the shield together with the magnetic field sensitive element and the winding surrounding the magnetic field sensitive element, thereby advantageously achieving additional protection of the winding from mechanical loads when assembled into the shield by the support plate.

[0208] By "connector neck" is understood the area of ​​the electrical connector which is configured to connect the support plate and the electrical contacts to each other.

[0209] By "electrical contacts" is understood elements of an electrical connector that are configured to make contact between electrical and / or electronic elements of the sensor.

[0210] In particular, the electrical contacts are formed in such a way that they protrude in two directions from the base material of the electrical connector. In that case, it should be borne in mind that contact between the electrical and / or electronic components of the sensor and the electrical contacts can be effected at the protruding ends of the contacts. Furthermore, it should be borne in mind that contact with the operating circuit of the sensor can be effected at different protruding ends of the electrical contacts, in particular by soldering, or by means of a plug connector corresponding to one or more electrical contacts.

[0211] In particular, the electrical contact consists of an alloy containing nickel in the range of 17 to 19% by weight, preferably 17.5 to 18.5% by weight, particularly preferably 18% by weight.

[0212] In particular, the electrical contact consists of an alloy containing 18 to 22% by weight of zinc, preferably 19 to 21% by weight of zinc, particularly preferably 20% by weight of zinc.

[0213] In particular, the electrical contacts are made of an alloy containing 58% by weight or more of copper, preferably 60% by weight or more of copper, and particularly preferably 61% by weight or more of copper.More preferably, the electrical contacts are made of an alloy containing 62% by weight or more of copper, even more preferably 63% by weight or more of copper, and particularly preferably 64% by weight or more of copper.

[0214] The above-described alloy compositions for electrical contacts advantageously allow for very good electrical conductivity, along with a relatively high modulus of elasticity and very good immersion tinning and soldering properties.

[0215] It is expressly pointed out that the above values ​​for the alloy composition of the electrical contacts should not be understood as definite limits, but rather should be able to be exceeded or fallen short on an engineering scale without departing from the described aspects of the invention. In short, these values ​​should provide an indication of the magnitude of the alloy composition of the electrical contacts proposed herein.

[0216] In particular, the electrical contacts have a gold coating, which advantageously makes it possible to improve the electrical conductivity of the electrical contacts.

[0217] By "opening" is meant an area in the shield through which the connector neck of an electrical connector connecting the support plate and the electrical contacts can extend from the receiving space in the shield to an area outside the shield, so that the electrical contacts of the electrical connector can be arranged outside the shield. For this purpose, the shield has an opening that corresponds in particular to the connector neck.

[0218] It should be kept in mind that in the case of a two-part shield, one or both parts of the shield may have a void that forms the opening after joining of the shield parts.

[0219] In particular, the opening is in the region of the outer wall of the shield.

[0220] By "void space" is understood an area in the cross section of the element that is not formed by the substrate of the element and that can therefore be penetrated by other objects without damaging the element.

[0221] In particular, the voids are channels through the substrate of the component.

[0222] Furthermore, in particular, the cavity is formed in the form of a recess in the base material of the part, whereby other objects can be inserted into the cavity through the opening of the recess.

[0223] By "corresponding cavities" in the connector neck and the support plate, it is understood that the cavities extend through both the support plate and the connector neck with a substantially constant contour in the main direction of extension of the cavities.

[0224] By "electric wire" is understood a flexible metal that is thin in the longitudinal direction. In particular, the electric wire has a circular cross section. In particular, the electric wire has a plurality of strands. In particular, the electric wire has a high proportion of copper.

[0225] A "notch" is understood to be a pointed or wedge-shaped cut.

[0226] The sensor according to the first aspect of the invention comprises a plurality of electric and / or electronic components, wherein during a specified operation of the sensor, an electric current is generated in or actively supplied to the electronic and / or electrical components.

[0227] These electrical and / or electronic components of the sensor must be designated and positioned in the receiving space of the shield and must be electrically contacted from outside the shield.

[0228] The simplest form of electrical contact is based on electrical wires connected to the electrical and / or electronic components being passed through the shield and soldered to the outside to a circuit board carrying the operating circuitry of the sensor.

[0229] This solution has many different sources of damage to the wire, and therefore to the sensor as a whole, which can lead to sensor failure. On the one hand, wires, which often have very small conductor cross sections, can easily be destroyed by mechanical loads, especially shear loads in the area of ​​the shield, or tensile loads between the windings and at the connections between the wire and the circuit board. Such tensile loads can occur during assembly of the sensor or even during operation of the sensor, when there is relative movement with the magnetic field-sensitive element and contact between the wire and the circuit board.

[0230] It is now proposed that the wires of the sensor be mechanically and electrically connectable by means of an electrical connector, thereby advantageously increasing the robustness and availability of the sensor.

[0231] The electrical connector proposed herein has a support plate arranged in the receiving space of the shield. A connector neck extends from the support plate as a second region of the electrical connector. The connector neck extends in particular through the shield, in particular in the region of the shield outer wall. A plurality of electrical contacts configured to be in electrical contact with electrical and / or electronic components of the sensor are connected to the connector neck.

[0232] The support plate allows for a force- and / or form-locking connection of the electrical connector with the sensor, in particular with the shield of the sensor.

[0233] The connector neck is configured to accommodate the electric wires and thus protect them from mechanical loads, particularly in the region of the shield, for which the connector neck and the support plate have corresponding cavities into which the electric wires can be inserted and which protect the electric wires from external mechanical loads.

[0234] Additionally, the connector neck fixes the relative position between the magnetic field sensitive element of the sensor and the electrical contact configured to make electrical contact therewith, and electrical wires can be threaded through corresponding cavities in the connector neck and support plate to the electrical contacts where they can be contacted.

[0235] The connector neck and the corresponding cavities of the support plate are finished in the form of troughs that are open transversely to the longitudinal extension of the corresponding cavities, so that the wires can be inserted into the cavities not only longitudinally but also transversely to the longitudinal direction. This design allows for advantages in assembling the sensor, since the wires can be inserted longitudinally and transversely to the longitudinal direction, one after the other and in bundles, which significantly simplifies the routing of the wires in the cavities.

[0236] The corresponding cavities in the connector neck and the support plate have notches extending transversely to the longitudinal axis of the corresponding cavities, with the tips of the notches pointing toward the cavities. The notches allow for easy transverse insertion of individual wires or bundles of wires into the cavities, with each wire passing through the narrowed portion of the notch. The narrowed portion of the notch is designed so that, once the wires are inserted into the cavities, they can only leave the cavities transversely to the longitudinal direction of the cavities with greater effort, thereby remaining in the designated protective area of ​​the cavities. This simplifies the assembly of the wires and ensures that the wires are protected, especially against mechanical loads, even after they are inserted into the cavities.

[0237] According to a second aspect of the present invention, there is provided a protective circuit breaker for interrupting a circuit in the event of a residual current exceeding a limit value occurring in the circuit, the protective circuit breaker comprising a sensor according to the first aspect of the present invention, an operating circuit, an electronic data processing and evaluation unit and a switching device, the sensor is arranged around at least two electrical conductors that form a circuit; - the switching device is set to interrupt the circuit; an operating circuit configured to operate the sensor; an electronic data processing and evaluation unit configured to evaluate the sensor signals of the sensors, The problem is solved by a protective circuit breaker, in which the electronic data processing and evaluation unit is configured to operate the switching device with a current intensity greater than a limit value, in particular an adjustable limit value, so that the switching device interrupts the circuit if a residual current is recognized, in particular if a residual current is recognized in a bi-current sensitive manner.

[0238] In this regard, the following terminology is mentioned: By "protective circuit breaker" is understood a device that is configured to shut down the voltage of a monitored circuit if a defined residual, in particular an adjustable residual current, is exceeded in the circuit monitored by the protective circuit breaker, in this way advantageously reducing the risk of residual currents to people and infrastructure.

[0239] By "operating circuit" is understood a circuit for active or passive operation of the sensor, in particular an operating circuit that is configured to supply a voltage to the first main winding and / or the second main winding of the sensor.

[0240] Furthermore, the operating circuit is designed in particular to tap off the voltage at the test winding of the sensor and transmit it as a signal to a data acquisition and evaluation unit.

[0241] Likewise, the operating circuit is also configured to tap off the voltage at the first main winding and / or the second main winding of the sensor and transfer it as a signal to the data acquisition and evaluation unit.

[0242] In particular, it should be borne in mind that the operating circuit also comprises a power consumption measuring device configured to evaluate the power consumption of the test winding and / or the first main winding and / or the second main winding.

[0243] An "electronic data processing and evaluation unit" is an electronic unit that organizes and processes large amounts of data with the goal of obtaining information about these data or modifying these aspects of the data, where the data are compiled in the form of data sets, processed in a defined manner by a person or machine, and the results are output.

[0244] By "data" is understood in particular measurements, in particular sensor signals, or the values ​​of other physical or chemical measurands or quantities.

[0245] By "switching device" is understood a device that is arranged to shut down the voltage supply of a circuit, in particular a circuit monitored by a circuit breaker.

[0246] By "circuit" is understood an electrical circuit consisting of a diameter of a conductor representing a closed path.

[0247] By "sensor signal" is understood a state quantity provided by a sensor. In particular, the sensor signal is configured such that it can be inferred from the sensor signal due to its physical and / or chemical dependence on the residual current of the circuit monitored by the sensor. In particular, the residual current monitored by the sensor can be calculated directly from the sensor signal. In particular, the sensor signal is a determinable current intensity and / or a determinable voltage.

[0248] "Current intensity" is understood to mean a current that measures the electrical current in the form of a physical quantity, in particular the current in an electrical circuit. In this case, the current intensity is related to a suitably oriented surface, in particular the cross section of an electrical conductor. In this case, the current intensity is the amount of charge that has flowed through the cross section and is related to the observed period.

[0249] In particular, the sensor signal is understood to be the power consumption of the first main winding, which can be converted into a residual current by mathematical rules.

[0250] By "limit value" is understood a defined value of a state quantity, in particular a residual current, which, if exceeded in a circuit monitored by a protective circuit breaker, will cause a switching device to shut down the voltage supply of the monitored circuit at the latest by the protective circuit breaker. In particular, the limit value of the circuit breaker can be adjustable.

[0251] That is, specifically proposed herein is a circuit breaker that utilizes a sensor according to the first aspect of the invention to monitor a circuit.

[0252] Needless to say, the advantages of the sensor for determining residual current according to the first aspect of the invention also extend directly to protective circuit breakers having a protective circuit breaker according to the first aspect of the invention, as described above.

[0253] This advantageously achieves a protective circuit breaker that is particularly sensitive to residual currents, so that the protective circuit breaker can interrupt the circuit even if the residual current in the monitored circuit is very small, and at the same time, it is advantageously achieved that the protective circuit breaker is particularly unlikely to erroneously detect a residual current that would erroneously exceed the limit current when the monitored circuit is switched on.

[0254] It is expressly pointed out that the subject matter of the second aspect may be advantageously combined with the subject matter of the preceding aspects of the invention individually or cumulatively in any combination.

[0255] According to a third aspect of the present invention, the problem is solved by a charging cable for charging an electric vehicle, the charging cable having a sensor according to the first aspect of the present invention and / or a protective circuit breaker according to the second aspect of the present invention.

[0256] In this regard, the following terminology is mentioned: By "charging cable" is understood an electrical connection that is designed to connect an electric vehicle to a power source, in this case the charging cable being designed to charge the traction battery of the electric vehicle, in particular the charging cable having a monitoring device for any residual current that may be present.

[0257] By "electric vehicle" is understood a vehicle that is at least partially driven by an electric motor, in particular an electric vehicle that is not track-bound or at least not permanently track-bound.

[0258] Here, a charging cable for charging a battery of an electric vehicle is proposed, comprising a protective circuit breaker according to the second aspect of the invention and / or a sensor according to the first aspect of the invention.

[0259] Needless to say, the advantages of the sensor for determining a residual current according to the first aspect of the present invention and / or the protective circuit breaker for interrupting the circuit if a residual current occurs in the circuit extend directly to a charging cable for charging an electric vehicle, as described above, which charging cable comprises a sensor according to the first aspect of the present invention and / or a protective circuit breaker according to the second aspect of the present invention.

[0260] It is expressly pointed out that the subject matter of the third aspect may be advantageously combined with the subject matter of the preceding aspects of the invention individually or cumulatively in any combination.

[0261] According to a fourth aspect of the present invention, there is provided a charging station for charging electric vehicles, the charging station comprising a sensor according to the first aspect of the present invention and / or a circuit breaker according to the second aspect of the present invention.

[0262] In this regard, the following terminology is mentioned: By "charging station" or "wall charging station" is understood a charger for charging electric vehicles. In the case of a wall charging station, the charging station is particularly designed to be mounted on a wall. In particular, the charging station is a mobile device that can be installed in various locations. In particular, the charging station or wall charging station provides, in addition to the plug-in connection of a charging cable for connecting the charging station to an electric vehicle and to the power supply network, other functions, in particular a monitoring device for any residual current that may occur.

[0263] Here, a charging station for charging electric vehicles is proposed, comprising a protective circuit breaker according to the second aspect of the invention and / or a sensor according to the first aspect of the invention.

[0264] Needless to say, the advantages of the sensor for determining a residual current according to the first aspect of the invention and / or the protective circuit breaker for interrupting a circuit in the event of a residual current in the circuit exceeding a limit value according to the second aspect extend directly to a charging station for charging electric vehicles, as described above, which charging station comprises a sensor according to the first aspect of the invention and / or a protective switch according to the second aspect of the invention.

[0265] It is expressly pointed out that the subject matter of the fourth aspect can be advantageously combined with the subject matter of the preceding aspects of the invention individually or cumulatively in any combination. Further advantages, details and features of the invention will become apparent from the examples described hereinafter. [Brief explanation of the drawings]

[0266] [Figure 1] FIG. 1 shows a schematic diagram of the arrangement of a sensor according to the invention in a circuit. [Figure 2] FIG. 2 is a diagram showing a schematic diagram of the physical interaction when the circuit is turned on. [Figure 3] FIG. 3 is a diagram showing a schematic diagram of the dynamic course of magnetic flux density over time at an exemplary location in a magnetic field sensitive element when the circuit is turned on. [Figure 4] FIG. 4 is a diagram showing a schematic diagram of the physical relationship between the inner width of the magnetic field sensitive element, the profile of the sensor's tendency to malfunction depending on the width, and the profile of the sensor's minimum measurable residual current depending on the inner width. [Figure 5] FIG. 5 is a schematic cross-sectional view of a sensor according to the present invention. [Figure 6] 6a to 6g are schematic diagrams of an electrical connector. DETAILED DESCRIPTION OF THE INVENTION

[0267] In the following description, the same reference numerals designate the same parts or features, and therefore a description given of a part with reference to a figure also applies to the other figures, thereby avoiding repetition. Furthermore, individual features described in connection with one embodiment can also be used separately in other embodiments.

[0268] The sensor 100, shown schematically in FIG. 1, is disposed around electrical conductors 110, 120 through which specified electrical currents 112, 114 flow in and out of a circuit (not shown) that is monitored by the sensor 100.

[0269] In that case, current 112 flows into the circuit (not shown) monitored by sensor 100 through outer conductor 110 and flows out again through neutral conductor 120 .

[0270] When a voltage source (not shown) in a circuit (not shown) is turned on, a dynamic physical interaction coupling occurs between the magnetic fields 114, 124 generated around the electrical conductors 110, 120 and the regional magnetic flux densities 116, 118 in the magnetic field sensitive element 10, as shown in FIG.

[0271] When a voltage supply (not shown) is turned on, magnetic fields 114, 124 originating from electrical conductors 110, 120 have a varied effect on magnetic field sensitive element 10 in a regionally and temporally limited manner, thereby producing magnetic flux densities 116, 126 in the magnetic field sensitive element 10 in opposite directions for a short period of time.

[0272] It is observed that the temporary and regionally opposite magnetic flux densities 116, 126 in the magnetic field sensitive element 10 result in a dynamic behavior of the magnetic flux density in the form of oscillations of the magnetic flux density 132 during its compensation process in FIG. 3 against time 130 at an exemplary location (not shown) in the magnetic field sensitive element 10.

[0273] This oscillation of the magnetic flux density 132 as a result of turning on a current source (not shown) for the observed circuit (not shown) undergoes a decaying transition and approaches its time limit along asymptotes 132, 134.

[0274] In that case, a brief oscillation of the magnetic flux density 132 leads to a physical interaction (not shown) with the test winding (not shown) and / or the first and / or second main winding, which generates a sensor signal (not shown), which can be interpreted as a residual current (not shown) exceeding a defined limit value (not shown), which can also be described as a switch-on error.

[0275] The relationship between the inner width 12 of the through opening (not shown) of the magnetic field sensitive element 10 shown in Figure 4, the tendency for malfunction 140 of the protective circuit breaker (not shown) for which the sensor 100 is specified and used, and the minimum residual current 150 measurable by the sensor 100 indicates that there is an optimal value 160 for the inner width 12 of the through opening (not shown) of the magnetic field sensitive element 10 at which a good compromise is found between the minimum measurable residual current 150 and the tendency for malfunction 140.

[0276] This optimum 160 is located at the intersection of the profiles 142, 152, as can be seen from the diagram presented here.

[0277] Furthermore, an optimum range 165 for the inner width 12 of the through opening (not shown) of the magnetic field sensitive element 10 has been identified, which is located around the optimum value 160 .

[0278] The sensor 100 of Figure 5 essentially consists of a magnetic field sensitive element 10, an insulator 20 surrounding the magnetic field sensitive element 10, a main winding 30, a test winding (not shown), a spacer ring 40, a shield 50, an electrical connector 60, and a plurality of electrical contacts 70.

[0279] The insulator 20 is formed in two parts, the individual parts (not shown) of the insulator 20 being form-fittingly connected to one another.

[0280] The main winding 30 is connected by electrical wires 75 to electrical contacts 70 carried by the electrical connector 60 .

[0281] The shield 50 is formed in two parts and defines a circumferentially extending gap 55 on the shield inner wall 58 .

[0282] The electrical connector 60 of FIG. 6 essentially consists of a support plate 80, a connector neck 90, and a plurality of electrical contacts 70.

[0283] In figure 6b) a three-dimensional view of the electrical connector 60 is shown.

[0284] In Figure 6a) a front view of the electrical connector 60 is shown, which is seen from the outside relative to the designated sensor.

[0285] Figure 6c) shows a top view of the electrical connector 60. Additionally, the section lines AA and BB are shown.

[0286] In figure 6d) the cross section AA of the electrical connector 60 is shown.

[0287] In figure 6e) cross section BB of electrical connector 60 is shown.

[0288] In Figure 6f) a front view of the electrical connector 60 is shown, the front view being from the inside relative to the designated sensor.

[0289] In figure 6g) a side view of the connector 60 is shown.

[0290] The support plate 80 is configured to be housed in a housing space (not shown) of a shield (not shown).

[0291] The connector neck 90 connects the plurality of electrical contacts 70 with the support plate 80 .

[0292] The connector neck 90 has a cavity 92 configured to receive two electrical wires (not shown) operatively coupled to each winding (not shown) from the receiving space (not shown) and to pass them from the receiving space (not shown) through openings (not shown) in the shield outer wall (not shown) to the electrical contacts (70).

[0293] The cavity 92 further has a notch 94 oriented parallel to the outer wall of the shield (not shown) through which an electrical wire (not shown) can be placed in a central region (not shown) of the cavity 92 .

[0294] The notches 94 allow the wires (not shown) to be inserted individually or in bundles simply transversely into the cavity 92, with the notch 94 having to be passed by each wire (not shown) at its narrow point (not shown). The narrow point (not shown) of the notch 94 ensures that once the wire (not shown) is placed in the cavity 92, it cannot re-exit the cavity 92 transversely to the longitudinal direction (not shown) of the cavity 92 except with great effort, and therefore remains within the designated protective area (not shown) of the cavity 92. [Explanation of symbols]

[0295] 10 Magnetic field sensitive element 12 Inner width 20 Insulators 30 Main Winding 40 Spacer ring 50 Shield 55 Circumferential gap 58 Shielding Inner Wall 60 Electrical Connectors 70 Electrical Contacts 75 Electric wire 80 Support Plate 90 Connector neck 92 void 94 Notch 100 sensors 110 Electrical conductor / outer conductor 112 Current direction 114 Magnetic field 116 Magnetic Flux Density 120 Electrical Conductor / Neutral Conductor 122 Current direction 124 Magnetic field 126 Magnetic Flux Density 130 Time Axis 132 Magnetic Flux Density Oscillations 134 Asymptote 136 Asymptote 140 False trigger tendency 142 False trigger tendency profile 150 Minimum measurable residual current 152 Minimum measurable residual current profile 160 Best Locations 165 Optimal Range

Claims

1. A sensor (100) for determining residual current in a bicurrent-sensitive manner, comprising: - the sensor (100) comprises a magnetic field sensitive element (10), a first main winding (30), a test winding and a shield (50); - the magnetic field sensitive element (10) has a magnetic field sensitive element through-opening, the magnetic field sensitive element through-opening of the magnetic field sensitive element (10) being shaped as an oval in cross section with two axes of symmetry; - the first main winding (30) and the test winding each having a plurality of windings surround the magnetic field sensitive element (10); the shield (50) has an accommodation space configured to accommodate the magnetic field sensitive element (10), the first main winding (30) and the test winding; - the containment space of the shield (50) is radially defined by an outer shield wall and an inner shield wall (58), the shielding inner wall (58) defines a shielding through-opening in the shielding (50), the shielding through-opening in the shielding (50) being shaped as an oval having two axes of symmetry; - the shield (50) has a circumferentially extending gap (55) in the region of the shield inner wall (58), - said sensor (100) is arranged to be placed around at least two electrical conductors (110, 120); a sensor in which the magnetic field sensitive element through-opening of the magnetic field sensitive element (10) has two inner widths along two axes of symmetry with different extensions, the inner width along the axis of symmetry having the greater extension is in the range of 25.2 to 32 mm; The sensor is characterized in that the circumferentially extending gap (55) has a gap width in the range of 0.1 mm to 2.0 mm.

2. 2. The sensor (100) of claim 1, wherein the magnetic field sensitive element (10) is covered by an insulator (20), and the insulator (20) is disposed between the magnetic field sensitive element (10) and the first main winding (30), and between the magnetic field sensitive element (10) and the test winding.

3. The sensor (100) of claim 1 or claim 2, characterized in that the sensor (100) has a second main winding (30), the second main winding (30) surrounding the magnetic field sensitive element (10) and / or the insulator (20) with multiple turns.

4. The sensor (100) according to any one of claims 1 to 3, characterized in that the sensor (100) comprises a spacer ring (40), the spacer ring (40) being disposed between the inner wall of the shield and the first main winding (30).

5. The sensor (100) according to any one of claims 1 to 4, characterized in that the shield (50) has a coating, in particular an electrically insulating coating.

6. The sensor (100) according to any one of claims 1 to 5, characterized in that the shield (50) has a material thickness in the range of 0.25 mm to 0.45 mm.

7. The sensor (100) has an electrical connector (60), the electrical connector (60) having a support plate (80), a connector neck (90), and a plurality of electrical contacts (70); - said electrical connector (60) has at least two electrical contacts (70) for each winding; - said electrical contacts (70) are arranged radially outside said shield outer wall, - the support plate (80) is arranged between the outer wall of the shield and the first main winding (30); - said connector neck (90) extends through an opening in said outer wall of the shield and connects said support plate (80) and said electrical contacts (70) together; - the support plate (80) and the connector neck (90) each have a corresponding cavity (92) configured to receive two electric wires (75) operatively associated with each winding from the receiving space and to pass them from the receiving space through openings in the outer wall of the shield to the electrical contacts (70); A sensor (100) according to any one of claims 1 to 6, characterized in that the cavity (92) has a notch (94) in a direction parallel to the outer wall of the shield, through which the electric wire (75) can be placed in the central region of the cavity (92).

8. A protective circuit breaker for interrupting an electric circuit when a residual current in said circuit exceeds a limit value, said circuit breaker comprising a sensor (100) according to any one of claims 1 to 7, said circuit breaker comprising an operating circuit, an electronic data processing and evaluation unit and a switching device, - said sensor (100) is arranged around at least two electrical conductors (110, 120) forming said electrical circuit; - the switching device is configured to interrupt the electrical circuit; - said operating circuit is configured to operate said sensor (100); - said electronic data processing and evaluation unit is configured to evaluate the sensor signals of said sensor (100), - a protective circuit breaker, wherein the electronic data processing and evaluation unit is configured to operate the switching device with a current intensity greater than a limit value, in particular an adjustable limit value, so that the switching device interrupts the electric circuit if a residual current is recognized, in particular if a residual current is recognized in a bi-current sensitive manner.

9. A charging cable for charging an electric vehicle, the charging cable comprising a sensor (100) according to any one of claims 1 to 7 or a protective circuit breaker according to claim 8.

10. A charging station for charging electric vehicles, the charging station comprising a sensor (100) according to any one of claims 1 to 7 or a protective circuit breaker according to claim 8.

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