Method, sensor device and current measuring system for measuring current flowing in conductor

Abstract

To provide a method, a sensor device and a current measuring system for determining a current flowing in a conductor.SOLUTION: A method includes the steps of: providing a plurality of magnetic sensor elements sensitive to a magnetic field (B) generated by a current to sensor positions relative to a predetermined reference point, respectively; outputting a sensor signal indicating characteristics of the magnetic field at each sensor position; receiving the sensor signal by a processing circuit; mapping the received sensor signal to an output value indicating a current; and outputting the output value. The step of mapping includes the use of multipole development of the magnetic field generated by the current, and the multipole development includes the predetermined number of predetermined multipole components and respectively related predetermined multipole coefficients.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The embodiments and aspects generally relate to the field of current sensors. More particularly, some embodiments and aspects relate to methods and sensor devices for determining the current flowing in a conductor. Some embodiments and aspects also relate to current measurement systems.

Background Art

[0002] Sensor devices (or sensor devices) for estimating the current flowing in a conductor are generally known in the art. The current flowing in a conductor generates a magnetic field. The current in the conductor can be determined by a magnetic sensor placed nearby sensing the associated magnetic field generated by the current. Current measurement is based on the principle of Maxwell's equations, which states that the magnitude of the magnetic field generated by the flow of current in a conductor is inversely proportional to the distance from the center of the conductor to the measurement point and proportional to the current flowing in the conductor. For example, U.S. Patent Application Publication No. 2017 / 0184635 (A1) describes a sensing device for characterizing the current passing through a conductor that includes a plurality of magnetic sensors.

Summary of the Invention

Problems to be Solved by the Invention

[0003] A fundamental problem with such sensor devices and systems is their long-term stability. An initially sufficiently accurate calibration of the sensor device or system changes over time, for example, due to mechanical displacement or misalignment of the components relative to each other, or due to drift of the electronic sensor characteristics.

[0004] Furthermore, such a sensor device may respond to an external magnetic field, for example, a magnetic field generated by another / adjacent current-carrying conductor (i.e., crosstalk), a stray magnetic field of another / adjacent magnetic component (or, magnetic component), the Earth's magnetic field, etc. Without countermeasures, these additional field components cannot be distinguished from the useful field, and as a result, the external magnetic field limits the accuracy of the sensor device or system.

[0005] Therefore, there is a need for a method, a sensor device, and a current measurement system for determining the current flowing in a conductor, distinguished by improved performance, which is evaluated, inter alia, with respect to operational robustness, numerical accuracy, long-term stability, application flexibility, and ease of production / implementation and cost-quality.

[0006] In particular, one objective is to provide a method, a sensor device, and a current measurement system for determining the current flowing in a conductor, which guarantees high operational robustness and long-term stability, for example, low sensitivity to interference caused by external magnetic fields not related to the current flow in the conductor such as those described above (e.g., stray magnetic fields, crosstalk, etc.), as well as low sensitivity to displacement or misalignment of components relative to each other, while providing accurate and reliable measurement results. Compatibility with different use cases and requirements of the method, device, and measurement system is also improved, for example, by not requiring shielding or a magnetic core, reducing the complexity and cost of manufacturing and implementation.

Means for Solving the Problem

[0007] Embodiments, implementations, and aspects are defined by the independent claims. The dependent claims define advantageous implementations.

[0008] Note that the individual features recited in the following description can be combined with each other in technically meaningful ways (and across different categories, e.g., apparatus and methods), and can show further embodiments. The descriptions of various examples, embodiments, and aspects are further characterized and specified, particularly in relation to the figures.

[0009] Furthermore, when used herein to combine a first and a second feature, the term "and / or" or the expression "at least one of" or "one or more of" should be understood to disclose a first embodiment having only the first feature, a second embodiment having only the second feature, and a third embodiment having both the first feature and the second feature. It should be understood that when three or more features are recited, any combination thereof should also be construed as a disclosed embodiment.

[0010] Furthermore, the terms "about", "substantially", or "approximately" indicate an acceptable range considered normal by those skilled in the art. In particular, the above terms should be understood to encompass an acceptable range of the recited amount up to ±20%, preferably up to ±10%.

[0011] Specific examples, embodiments, and aspects are often described with reference to specific drawings, but the claimed subject matter is limited only by the claims.

[0012] The terms "first", "second", etc. in this specification and the claims are used to distinguish similar elements and are not necessarily used to describe an order in any way, whether in time, space, ranking, or any other way. It should be understood that such terms are interchangeable under appropriate circumstances and that the embodiments described herein can operate in other orders than those described or illustrated herein.

[0013] Furthermore, terms such as above, below, front, back, leading, trailing, down, up, etc. in this specification and the claims are used for the purpose of explanation to refer to the orientation of the illustrated drawings and are not necessarily for describing absolute positions. Since the components of the embodiments can be arranged in several different orientations, the directional terms are used for illustrative purposes only and are never intended to be limiting, unless otherwise indicated. Therefore, the terms used as such are interchangeable under appropriate circumstances, and it should be understood that the embodiments described herein are capable of operating in other orientations than those described or illustrated herein.

[0014] It should be noted that the term "comprising" used in the claims should not be construed as being limited to the elements listed thereafter. It does not exclude other elements or steps. Therefore, it should be construed as identifying the presence of the recited features, integers, steps, or components, but not precluding the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the scope of the expression "a device comprising features A and B" should not be limited to a device consisting only of features A and B. It means that the device may have additional elements or features of the device that are A and B.

[0015] Throughout this specification, references to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, although they may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, as will be apparent to those skilled in the art from this disclosure.

[0016] Similarly, in the description of the exemplary embodiments, it should be understood that for the purpose of simplifying the disclosure and assisting the understanding of one or more of the various aspects of the invention, various features may be grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the following claims represent, inventive elements do not necessarily exist in all the features of a single embodiment previously disclosed. Thus, the claims following the mode for carrying out the invention are clearly incorporated into the mode for carrying out the invention, and each claim stands on its own as a separate embodiment.

[0017] Furthermore, some of the embodiments described herein include some embodiments that are included in other embodiments but do not include other features, while combinations of features of different embodiments are within the scope of the present disclosure and are meant to form different embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0018] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0019] According to one example, a method for determining the current flowing through a conductor (e.g., a cable, a bus bar, etc.) is - At each sensor position with respect to a predetermined reference point (also referred to herein as the "origin of the multipole expansion"), providing a plurality of magnetic sensor elements (e.g., Hall elements, circular Hall elements, lateral (or horizontal) Hall elements, vertical Hall elements, magnetoresistive (MR) elements, AMR elements, XMR elements, GMR elements, TMR elements, etc.) that are sensitive to (or sensitive to) the magnetic field generated by the current. - Outputting, by the magnetic sensor elements, sensor signals indicating the characteristics of the magnetic field at each sensor position, e.g., the magnetic field components directed in a specific direction. - Receiving, by a processing circuit (e.g., but not limited to, an electronic processor, a microcontroller, a microprocessor, a digital signal processor, etc.), the sensor signals from the magnetic sensor elements or circuits (e.g., a Wheatstone bridge including the sensor elements). - Mapping, by the processing circuit, the received sensor signals to an output value indicating the current flowing through the conductor. - Outputting the output value, for example, as the measured current. The step of mapping includes using a multipole expansion of the magnetic field generated by the current with respect to the predetermined reference point, and the multipole expansion includes a predetermined number of predetermined multipole components and their respective associated predetermined multipole coefficients. These coefficients can be stored in the non-volatile memory (e.g., flash) of the sensor device.

[0020] The plurality of sensor elements may be mounted on one or more printed circuit boards (PCBs), e.g., on a single PCB.

[0021] The position of the reference point can be a predetermined position in the cross-sectional area (or cross-sectional area) of the conductor.

[0022] Some aspects are based on the idea of not only measuring the magnetic field generated by a current flowing through a conductor at a spatial point, but also determining the intensity of the spatial harmonics or spatial pattern of the magnetic field generated by the current. The spatial harmonics / patterns are the mathematical equivalent of a magnetic multipole expansion. The intensity of the spatial harmonics / patterns of the magnetic field generated by the current flowing through the conductor is a characteristic of the conductor shape that does not change over time. Thus, methods for determining the current in a conductor according to some examples are insensitive to (at least local) variations in the actual sensor position with respect to the conductor. In some examples, a spatial (solid, fixed, non-time-varying) pattern is used so as to be independent of small relative movements between the sensor element (or the printed circuit board on which the sensor element is mounted) and the conductor. This applies to both direct current (DC) and alternating current (AC) currents flowing through the conductor. Even in the latter case where AC currents of different frequencies create slightly different spatial patterns (e.g., due to the skin effect), i.e., the multipole expansion exhibits frequency dependence, this frequency dependence is not time-dependent in the sense that it does not degrade over time.

[0023] Similarly, the method is also robust to interference by external fields not related to the flow of current in the conductor, such as stray magnetic fields, crosstalk. These characteristics enable an accurate determination of the current in the conductor. Thus, some embodiments make it possible to omit the magnetic core and / or shield (i.e., facilitate coreless and shieldless sensor devices) without sacrificing accuracy, which results in cost savings and increased bandwidth since ferromagnetic core materials generally limit the bandwidth to a few tens of kHz, e.g., 200 kHz, 100 kHz, 50 kHz, or even lower, e.g., 30 kHz, 20 kHz, 10 kHz.

[0024] It should be emphasized that the sensor signals together provide the required intensity of the spatial harmonics / patterns of the magnetic multipole expansion.

[0025] The method can include, for example, an additional step of arranging the sensor element in a predetermined manner with respect to the conductor by arranging a printed circuit board (PCB) including the sensor element in a predetermined manner with respect to the conductor. The sensor elements have a relative position and orientation fixed to each other (since they are mounted on the PCB). After arranging the PCB in a predetermined manner with respect to the conductor, each sensor element also has a predetermined position and orientation with respect to the conductor.

[0026] In some embodiments, the method includes an additional step of providing a conductor.

[0027] A method for determining the current flowing in a conductor as described above (e.g., a cable, a bus bar, etc.) can alternatively be specified according to an embodiment including the following steps: - Providing a plurality of magnetic sensor elements (e.g., Hall elements, circular Hall elements, lateral Hall elements, longitudinal Hall elements, magnetoresistive (MR) elements, AMR elements, XMR elements, GMR elements, TMR elements, etc.) sensitive to the magnetic field generated by the current at each sensor position with respect to a predetermined reference point (also referred to herein as the origin of the multipole expansion); - Outputting, by the magnetic sensor element, a sensor signal indicating a characteristic of the magnetic field at each sensor position, e.g., a field component of the magnetic field directed in a specific direction; - Receiving, by a processing circuit (e.g., but not limited to, an electronic processor, a microcontroller, a microprocessor, a digital signal processor, etc.), the sensor signal from the magnetic sensor element or circuit (e.g., a Wheatstone bridge including the sensor element); - Mapping, by the processing circuit, the received sensor signal to an output value indicating the current flowing in the conductor; - Outputting the output value, for example, as the measured current, The mapping step includes position compensation such that the mapped output value is substantially invariant to changes in the relative position between the sensor element and the conductor.

[0028] Generally, the sensor element can be configured to detect a predetermined or arbitrary field component of the magnetic field, i.e., the Bx, By, and / or Bz field components with respect to three spatial directions x, y, and z.

[0029] Additionally or alternatively, signals from at least some of the sensor elements can be combined to detect the magnetic field gradient of the magnetic field in an arbitrary spatial direction such as x, y, and / or z (e.g., addition, subtraction, linear combination, etc.).

[0030] Note that in either case, sensor elements that measure the same information, i.e., have the same sensor position and measure the same spatial field component of the magnetic field, do not contribute to the total number of sensor elements.

[0031] On the other hand, when the sensor elements measure magnetic fields in different spatial directions, a single package sensor (e.g., one SMD package, etc.) that measures magnetic fields in different spatial directions at the same location can be counted as multiple sensor elements. For example, a bidirectional sensor package (also called a "2D magnetic sensor") at one physical sensor position should be interpreted as two sensor elements.

[0032] The method can include an additional step of arranging the sensor elements in a predetermined manner with respect to the conductor, for example, by arranging a printed circuit board (PCB) including the sensor elements in a predetermined manner with respect to the conductor. The sensor elements have a relative position and orientation fixed to each other (because they are mounted on the PCB). After arranging the PCB in a predetermined manner with respect to the conductor, each sensor element also has a predetermined position and orientation with respect to the conductor.

[0033] In some embodiments, the method includes an additional step of providing a conductor.

[0034] In some embodiments, all or some of the sensor elements can detect a magnetic field oriented in the same spatial direction, i.e., detect the same field component of the magnetic field or the magnetic field gradient.

[0035] In other embodiments, at least some or all of the sensor elements may be configured to detect magnetic fields in different spatial directions, i.e., detect different field components or field gradients of the magnetic field, or their signals may be combined (e.g., added, subtracted, linearly combined, etc.). Providing sensor elements that are sensitive to different spatial directions delivers more information in order to compensate for the lifetime spatial position variations between the sensor elements and the conductor and to suppress external magnetic field interference.

[0036] Preferably, these sensitivity directions span an angle of 90°.

[0037] In one embodiment, some sensor elements are configured to sense the magnetic field component in a first direction (e.g., X), typically denoted as Bx, some sensor elements are configured to sense the magnetic field component in a second direction (e.g., Y) perpendicular to the first direction (X), typically denoted as By, and optionally, some sensor elements are configured to sense the magnetic field component in a third direction (e.g., Z) perpendicular to the first direction (X) and perpendicular to the second direction (Y), typically denoted as Bz.

[0038] In yet another preferred embodiment, the sensor positions are determined such that the spatial distance between at least two of the sensor elements is greater than the maximum operating spatial position variation of the relative position between the sensor elements and the conductor over the lifetime desired to be compensated. In this way, it is ensured that the sensor elements can measure the associated field variations due to the spatial position variations.

[0039] In a particular embodiment, the conductor has a rectangular cross-section with length L and width W, and at least two sensor elements are separated by a distance greater than the smaller of L and W.

[0040] In certain embodiments, the conductor has a diameter D or a maximum diagonal D, and at least two sensor elements are spaced apart by a distance greater than D.

[0041] In yet another advantageous embodiment, the sensor positions are determined such that they are in highly symmetric positions, for example, within a symmetry plane / mirror plane, which provides less signal variation over the lifetime (due to the vanishing gradients to be compensated there) than the positional variations to be compensated (or, less than / under). Alternatively, some of the sensor positions can be selected to be symmetric points / mirror points (or, mirror image points) with respect to the symmetry plane / mirror plane such that the sum or difference of the corresponding signals essentially compensates for the spatial variations to first order, providing a more robust system.

[0042] Furthermore, the magnetic sensor elements are configured such that the signal difference measured along the same spatial direction must be significantly larger than the typical noise amplitude of the sensor elements for which the signal difference is used.

[0043] For the following explanations, boldface represents a vector or a matrix depending on the context (in this translation submission document, the characters within <> can represent a vector or a matrix depending on the context).

[0044] Generally, the magnetic field generated by the current in the conductor (In this specification, also called the induced field as a synonym) is the number M at a predetermined sensor position of the sensor element within the region of interest, that is, m of the multipole <m α > can be described as a superposition.

[0045] Free space (that is, the induced field in TIFF2025097283000002.tif6170) The multipole expansion is TIFF2025097283000003.tif18169, where <x>is the position vector, M m is the multipole component <m α > of a predetermined number, B i ( <x>) is the i-th vector component of the induced field distribution, c α ∈ R are the multipole coefficients associated with each multipole component, TIFF2025097283000004.tif7169 shows the distribution of the i-th vector component of the α-th multipole. The allowable multipole components satisfy TIFF2025097283000005.tif11169 and follow Maxwell's equations TIFF2025097283000006.tif6169.

[0046] The coefficient C α may be determined by simulation or by measurement.

[0047] According to a further advantageous embodiment, the multipole coefficient C α consists of the system matrix of the number of multipole components evaluated at the sensor position <m>and the vector on the right side formed by the received sensor signal The solution vector of the linear system given by the equation TIFF2025097283000007.tif6169 <c>determined as such, when the number of magnetic sensor elements in the linear system of equations is equal to the number of multipole components, the system matrix <m>By the inverse matrix (or inverse) of, when the number of magnetic sensor elements is greater than the number of multipole components, by the least squares normal equation, and when the number of magnetic sensor elements is less than the number of multipole components, by selecting the minimal norm solution, that is, the system matrix <m>It is solved by using the pseudo-inverse matrix (or pseudo-inverse).

[0048] In other words, the multipole coefficient is a vector determined by minimizing the square of the norm TIFF2025097283000008.tif6169 <c>is an element, where the system matrix <m>is composed of the number of multipole components evaluated at the sensor position, and the vector is formed by the received sensor signals, where, when the number of sensor elements is less than the number of multipole components, the minimum value is the solution vector <c>Minimum norm Found with additional side conditions (or additional edge conditions) of TIFF2025097283000009.tif6169 (or the minimum norm of the solution vector Found with the additional side conditions of TIFF2025097283000010.tif6169).

[0049] In some embodiments, the multipole coefficient C α Is determined during the calibration phase of an electrical assembly comprising a conductor and a magnetic sensor element, where a sensor signal is received by a processing circuit while a predetermined calibration current is applied to the conductor. The multipole coefficient may be stored in a non-volatile memory (e.g., flash) mounted on a PCB or embedded in a sensor device.

[0050] In further embodiments, the multipole coefficient is purely determined by calculations based on the geometric relationship of the sensor position with respect to the conductor, for example by using finite element (FE) simulations. The purely pre-calculated multipole coefficient can function as a starting point before the calibration phase where the multipole coefficient is more accurately determined, depending on the actual manufacturing tolerances of the current sensor device or current measurement system, for example.

[0051] The magnetic field of the conductor is linear with respect to the current flowing through the conductor. This can be reflected in the multipole expansion by the following equation: TIFF2025097283000011.tif18169 where TIFF2025097283000012.tif7169 is the predetermined calibration current I applied to the conductor during the calibration phase of the magnetic sensor element cal Of the expansion coefficients, and γ = I meas / I cal Is the linear coefficient (also referred to herein as the relative current amplitude) that provides the multipole coefficient of the current I meas To be determined in the conductor after the calibration phase, i.e., during the intended measurement phase.

[0052] Given sensor position d j for a given number N s of sensor elements (which are partially identical when different spatial field directions are measured at the same sensor position, i.e., for some n ≠ m, TIFF2025097283000013.tif7169), if the current in the conductor is I cal is equal to the case TIFF2025097283000014.tif19169 is characterized by.

[0053] In the calibration phase, the sensor elements are positioned in a predetermined manner with respect to the conductor (e.g., by arranging the PCB containing the sensor elements in a predetermined way with respect to the conductor), and for j = 1,..., N s the sensor signals for TIFF2025097283000015.tif8169 are measured by the sensor elements for a predetermined fixed calibration current I cal with respect to. To calibrate the sensor elements, Equation (1) becomes TIFF2025097283000016.tif20169, which is solved for those of c α with respect to.

[0054] Preferably, the above solutions are then stored in the non - volatile memory (e.g., flash) of the sensor device or connected to the processing circuit from where they can be retrieved (or, preferably, the above solutions are then stored in the non - volatile memory (e.g., flash) of the sensor device or connected to the processing circuit from where they can be retrieved).

[0055] The number N of sensor signals s is greater than the number M of multipole components m this provides a linear least - squares (LS) fitting problem. Since the sensor positions <d j > are predefined by the actual design, the system matrix TIFF2025097283000017.tif8169 is assumed to be known. The solution to this problem is given by the LS normal equations. The matrix defined by TIFF2025097283000018.tif8169 Using this, the following is obtained: TIFF2025097283000019.tif20169

[0056] If the number of sensor signals is less than the number of multipole coefficients of unknown multiplicity, i.e., N s <M m The same equation applies also in the case of. This solution is the minimum norm within the infinite set of solutions for the system of undetermined linear equations characterized by TIFF2025097283000020.tif9169. The corresponding matrix A αj is the pseudo-inverse matrix of matrix M jα . It is reasonable to assume that this solution is the correct one from a physical point of view. Furthermore, it is desirable to use as many sensor signals as there are independent multipole components.

[0057] According to a further advantageous embodiment, the mapping step further includes predicting the sensor signal as a predicted sensor signal from the previous output value using a linear combination of multipole components evaluated at each sensor position and weighted with the respective associated multipole coefficients, and correcting the output value according to the difference between the predicted sensor signal and the received sensor signal.

[0058] The above prediction is based on a given measurement model that describes the physical system (or physical system) on which the current is determined. Using the given multipole coefficients TIFF2025097283000021.tif7169 known from the calibration phase, for example, the measurement model is obtained from Equations 1 and 2, and the sensor signal for the unknown current I meas =γ·I cal can be predicted as follows: TIFF2025097283000022.tif18169

[0059] The experiment showed that the Kalman filter approach provides a well - suited scheme for performing signal processing to determine the current in a conductor. The Kalman filter depends on a state vector (also called the output value herein) that includes state variables that completely define the state of the underlying physical system, a set - up of a set of dynamic models that describe the temporal variation of the state variables forming the state vector, and a measurement model that connects the (raw) sensor signal to the system state.

[0060] In the above - mentioned case, the only state variable is γ, which completely defines the physical system so as to derive all relevant physical properties.

[0061] In yet another embodiment, the mapping step further includes determining the actual translational and / or actual rotational displacement of the sensor position relative to the sensor position in the calibration stage.

[0062] In addition to the current to be determined, if there is an unknown translation between the actual sensor position and the sensor position in the calibration stage, the measurement model given above can be extended to account for the translational displacement as follows: TIFF2025097283000023.tif19169

[0063] This is because the multipole coefficients are the linear scaling coefficient γ and possibly the translation vector <t>This is to represent the magnetic field of a conductor that does not change except for this. Equation (4) provides the basis for a robust determination of the current in a conductor under (small / local) spatial distortion.

[0064] When the relative position of the sensor element and the conductor includes rotational displacement, the measurement model can be generalized as follows: TIFF2025097283000024.tif18169 Here, <R(θ)> corresponds to the rotation matrix along the longitudinal axis of the conductor by the angle θ, and it is required to include θ as an additional state variable.

[0065] The magnetic sensor element may be mounted on a common rigid body (e.g., a printed circuit board, PCB) such that all translational and / or rotational movements of the sensor element relative to the conductor are substantially the same for all sensor elements.

[0066] Note that the update rate of the actual displacement of the sensor position and the update rate for determining the current in the conductor may be different as further explained below. Alternatively, both update rates may be the same.

[0067] As an example, the most basic state vector in the above case of the translational displacement of the sensor element relative to the conductor is (γ,t x ,t y ) T given by. When these state variables are known, the system is completely defined and all relevant characteristics of the underlying physical system can be derived. Further below, some variations of this system state are introduced, which lead to a more performant approach.

[0068] The simplest dynamic model for the state vector in this case assumes that all state variables are stationary but are subject to the following white noise: TIFF2025097283000025.tif20169 Here, the vector η=(η γ ,η tx ,η ty ) T represents a random variable of white noise with a vanishing mean, and its covariance is given by: TIFF2025097283000026.tif25169

[0069] the so-called process variance σ γ etc. correspond to empirically unknown temporal variations of the state variables that are not modeled.

[0070] The measurement model is given by Equation (4), i.e., TIFF2025097283000027.tif19169, where the random variable ν for white noise with respect to sensor element j j is added to account for measurement noise (also zero mean and characterized by variance σ Sj ). This model is a multipole TIFF2025097283000028.tif6169 with a translation vector <t>may depend non-linearly on (see the multipole components <m 5 > given further below), and since they are further multiplied by γ, they are generally non-linear. This approach may correspond to an extended Kalman filter.

[0071] For this purpose, an estimator-corrector-scheme may be provided to update the state vector based on new evidence, i.e., the newly measured and received sensor signal s j The covariance cov(η) enables an accurate attribution of signal changes to the most likely cause when it is not deterministically given due to measurement noise. If the system only undergoes slow spatial position changes (e.g., over its lifetime), the change in the conductor current (i.e., the state variable γ) is translational <t>Much more likely as a cause of (raw) sensor signal fluctuations compared to the changes of

[0072] On the other hand, a system subject to vibrations may undergo position changes on a similar or even faster time scale compared to the current variables. In this case, for example, TIFF2025097283000029.tif6169 etc. may be characterized by a much larger value of process variance.

[0073] Therefore, different update rates may be appropriate for translational and / or rotational displacements and for the determination of the current in the conductor and are considered in various embodiments.

[0074] According to a further advantageous embodiment, the reference point is preferably determined to be within the plane of symmetry of the conductor (or actually a small part of the conductor). Such a plane of symmetry may be a mirror plane such as a plane containing the longitudinal axis of a long straight conductor. The conductor may be, for example, a relatively long straight busbar having a rectangular cross-section, but even if the busbar is short or curved, the reference point is preferably selected with respect to the shape of the cross-section in a plane perpendicular to the direction of the local current flow.

[0075] Alternatively or additionally, the reference point may be determined to be on the axis of inversion symmetry of the conductor or at its inversion point.

[0076] In both cases described above, it is possible to reduce the number of multipole components that must be considered in the multipole expansion to determine the current in the conductor. This is because the corresponding associated multipole coefficients of these multipole components become zero, so that the magnetic field generated by the current cannot contribute to a specific spatial direction at this plane of symmetry or symmetry point. Therefore, choosing the reference point to be at a point or plane of high symmetry advantageously reduces the computational effort for the processing circuit, which for example allows the use of less powerful hardware.

[0077] Furthermore, by using the symmetry of the conductor, the spatial dimensions to be considered for the multipole expansion can also be reduced. For example, since the field of interest is rendered to be 2D by the symmetry of the conductor (e.g., a long straight conductor such as a bus bar), it may be sufficient to consider the multipole expansion only for two spatial dimensions (2D) instead of three spatial dimensions (3D). This further reduces the computational effort for the processing circuit.

[0078] Additionally or alternatively, the reference point or origin of the multipole expansion can be selected to be at a short distance from the sensor position of the sensor element. Placing the sensor element close to the reference point leads to a multipole expansion that converges rapidly. Thus, the contribution of the higher-order multipole components vanishes rapidly and need not be considered to obtain accurate and robust results.

[0079] In some embodiments, it has been found that accurate and robust results can be obtained when the multipole expansion is up to second order in the spatial coordinates, i.e., including zero order, first order, and second order.

[0080] As an example, in a 2D situation, the number M of multipole components up to second order m = 6 (when given as the vector of the induction field in a plane perpendicular to the longitudinal axis of the conductor, e.g., a bus bar) is TIFF2025097283000030.tif27169, where x1 represents the first spatial direction in the plane (also referred to herein as the x - direction), and x2 represents the second spatial direction in the plane (also referred to herein as the y - direction). The third spatial direction, i.e., x3 or the z - direction, need not be considered when the conductor extends straight along its longitudinal axis and has a uniform cross - section.

[0081] In addition to the selection of the number of expansion orders to be considered, the origin (i.e., the reference point) of the multipole expansion can also be advantageously selected. For example, this point can be selected to be at the geometric center (i.e., the centroid) of the sensor element. This ensures a short distance from the sensor element to the reference point. And the values entering the coordinate variables (i.e., x, y, z, namely x1, x2, and x3 respectively) become small, that is, the relative contributions rapidly become small for higher-order multipole components.

[0082] The number of multipole components described above corresponds to a situation where the magnetic field at the origin of the multipole expansion shows no symmetry. If symmetry exists, for example, if there is a mirror plane due to the symmetry of the conductor shape, the number of multipole components is reduced. As an example, when the conductor has a flat and elongated shape, there is no y-direction field component of the magnetic field at the intermediate plane (i.e., the symmetry plane) along the longitudinal axis of the conductor. This corresponds to the disappearance of the multipole coefficient c2 of TIFF2025097283000031.tif11169 when the origin is selected at the intermediate plane. TIFF2025097283000031.tif11169 corresponds to the disappearance of the multipole coefficient c2.

[0083] In some embodiments, the determined current is direct current (DC).

[0084] In other embodiments, the determined current is alternating current (AC), and the mapping step further includes a step of determining the instantaneous phase of the alternating current.

[0085] In this case, the dynamic model of the current variable γ may be extended to describe an AC current, and this state variable is no longer constant and corresponds to harmonic fluctuations. I meas (t)=γsin(φ)·I cal Using the parametrization of the AC current to be determined, given by, the dynamic prediction model is improved as follows (see Equation 5): TIFF2025097283000032.tif30169 Here, ω represents the angular frequency of the determined AC current, and φ represents its instantaneous phase.

[0086] According to a further embodiment, two or more conductors are provided, and determining the current includes determining the individual currents flowing in each of the conductors, and for each of the conductors, a separate multipole expansion is used.

[0087] The determination of three-phase alternating current can also be carried out using the principles disclosed herein. For each of the three phases, a set of sensor signals TIFF2025097283000033.tif8169 (X ∈ U, V, W) is measured. For the B-field generated by the three conductors, a separate multipole expansion is performed. Instead of the scalar variable γ, the three-phase relative current amplitude vector γ = (γ U , γ V , γ W ) T is introduced to describe the three-phase relative current amplitudes.

[0088] When the phases interfere with each other, i.e., when the system exhibits crosstalk, the corresponding measurement model must include, for example, the influence of phase U on phase V. Since the different phases are separated by a much larger distance compared to the sensor positions of the sensor elements per phase, this crosstalk will include only the lowest-order multipoles (e.g., up to linear in the spatial coordinates) in order to reduce the workload in signal processing.

[0089] The dynamic model of the three-phase current can incorporate specific correlations inherent in this case. In this way, the measured signals are fully utilized (or leveraged) against the prior knowledge of the three-phase characteristics, thereby improving the measurement accuracy.

[0090] In a particular embodiment, a single PCB is attached at a predetermined position with respect to three conductors (e.g., three bus bars), the single PCB includes two groups of sensor elements, and each group of sensor elements is arranged in the space between two conductors (e.g., as shown in FIG. 14). Each group may include, for example, at least two or at least three magnetic sensor elements. In this case, only a single translational and rotational vector is applicable to all of the magnetic sensors.

[0091] In a variant, two PCBs are attached at a predetermined position with respect to three conductors (e.g., three bus bars), each of the PCBs includes a group of sensor elements, and each group of sensor elements is located in the space between two conductors. Each group may include, for example, at least two or at least three magnetic sensor elements. In this case, a first translational and rotational vector is applicable to the magnetic sensors of the first PCB, and a second translational and rotational vector is applicable to the magnetic sensors of the second PCB.

[0092] Depending on the mechanical structure of the conductor arrangement, the number of mechanical degrees of freedom (i.e., translational vectors, rotation angles) can be increased to separately address the relative position changes of each conductor. This is certainly necessary if they do not behave as a rigid body assembly.

[0093] All sensor signals can be determined uniformly in time (i.e., simultaneously) to provide simultaneous state variable updates. This results in complex matrix operations taking into account all cross-correlations. However, it is also possible to perform state variable updates stepwise according to the measurements, not uniformly or simultaneously, i.e., sensor element after sensor element.

[0094] In particular, for three-phase AC current, a hybrid approach seems to be particularly advantageous, i.e., one of the sensor signals of the individual sensor elements of each phase is received simultaneously and the three-phase relative current amplitudes are updated. However, the remaining state variables that describe the spatial position are only updated when all sensor signals are newly received. In this way, the computational effort is minimized and at the same time the fluctuations of the relative current amplitudes are minimized.

[0095] According to a further advantageous embodiment, the signals from the various sensor elements can be combined to correspond to the magnetic field gradient at each sensor position with respect to a predetermined spatial direction. From the gradient, even more accurate information about the position change of the actual sensor position (i.e., translation and / or rotation) can be derived.

[0096] In yet another embodiment, the number of magnetic sensor elements is greater than or equal to the number of multipole components.

[0097] Generally, the minimum number N of sensor signals required to determine the current in a conductor s is equal to the maximum value of the number of degrees of freedom of the system given by the number N of current phases p and the number N of mechanical rigid body motions r i.e., TIFF2025097283000034.tif7169.

[0098] For best accuracy, the number M of multipole components involved m should also be considered. It is possible to perform calibration for M m >N s using the pseudo-inverse matrix approach described herein, but the calibration accuracy is improved for M m ≦N s i.e., TIFF2025097283000035.tif8169.

[0099] Some examples are shown below.

[0100] <Example 1> For a long, straight conductor (e.g., a bus bar or a cable), the B-field components to be considered are only those in a plane perpendicular to the conductor. The number M of the maximum first-order multipole components m = 4 (i.e., TIFF2025097283000036.tif6169), a single current phase (N p = 1), and two translational degrees of freedom (N r = 2) regarding the relative displacement of the sensor position of the sensor element with respect to the conductor, then Ns ≧ 3 can be seen.

[0101] <Example 2> By placing the origin (i.e., the reference point) of the multipole expansion within the symmetry plane of the conductor, for example, in the case of a strip bus bar, the origin can be determined to be within the middle plane of the bus bar cross-section, TIFF2025097283000037.tif8169 or TIFF2025097283000038.tif6169 does not contribute to the magnetic field due to symmetry. And M m = 3, N p = 1 and N r = 2, and , N s ≧ 3 holds, where this number of sensor signals enables a complete characterization of the multipole coefficients during calibration.

[0102] <Example 3> The system described in Example 1, but having an additional rotational degree of freedom in addition to the two translational degrees of freedom, i.e., for a system with N r = 3, Ns ≧ 4 holds.

[0103] However, in this case, the origin of the multipole expansion is not determined to be within the symmetry plane of the conductor, and thus the necessary information cannot be provided by the sensor element in the first place.

[0104] <Example 4> Here too, selecting an appropriate starting point for the multipole expansion reduces the number of excited multipole components, for example, to M m = 4, and Ns ≥ 4 according to, N r = 3 degrees of freedom of the rigid body (including rotation here) and a single current phase N p = 1 will enable a system.

[0105] According to a further aspect, a current sensor device for determining the current flowing in a conductor (e.g., a cable, a bus bar, etc.) is - a plurality of magnetic sensor elements (e.g., analog or digital sensor elements such as Hall elements) sensitive to the magnetic field generated by the current, each of the magnetic sensor elements being arranged at a respective sensor position with respect to a predetermined reference point (also referred to herein as the starting point of the multipole expansion), and configured to output a sensor signal indicating the field component of the magnetic field at each respective sensor position; the magnetic sensor elements and - a processing circuit (e.g., but not limited to, an electronic processor, a microcontroller, a microprocessor, a digital signal processor, etc.) configured to receive the sensor signals from the magnetic sensor elements, wherein the processing circuit is configured to map the received sensor signals to an output value indicating the current flowing in the conductor and output the output value, and the mapping includes using a multipole expansion of the magnetic field generated by the current with respect to the predetermined reference point, the multipole expansion including a predetermined number of predetermined multipole components and respective associated predetermined multipole coefficients.

[0106] Regarding the effects and advantages of the features of the sensor device disclosed herein, it should be noted that the whole of it is referred to the corresponding similar features of the method, as well as the effects and advantages thereof disclosed herein. Therefore, the features of the method should be regarded as applicable features for the definition of the embodiments of the sensor device unless otherwise explicitly stated, and vice versa. Therefore, in order to simplify this specification and better understand the principle, the description of such similar features, their effects and advantages can be omitted, but such omissions should not be construed as limitations.

[0107] A sensor device for determining the current flowing through a conductor (such as a cable, a bus bar, etc.) as described above may alternatively - a plurality of magnetic sensor elements (such as Hall elements, circular Hall elements, lateral Hall elements, longitudinal Hall elements, magnetoresistive (MR) elements, AMR elements, XMR elements, GMR elements, TMR elements, etc.) sensitive to the magnetic field generated by the current, each of the magnetic sensor elements being arranged at a respective sensor position with respect to a predetermined reference point (also referred to herein as the origin of the multipole expansion), and configured to output a sensor signal indicating the characteristics (such as field components) of the magnetic field at each respective sensor position, the magnetic sensor elements; - a processing circuit (such as, but not limited to, an electronic processor, a microcontroller, a microprocessor, a digital signal processor, etc.) configured to receive a sensor signal from the magnetic sensor elements, and wherein the processing circuit is configured to map the received sensor signal to an output value indicating the current flowing through the conductor and output the output value, and the mapping includes position compensation such that the mapped output value is invariant to changes in the relative position between the magnetic sensor elements and the conductor, is specified according to an aspect.

[0108] In an advantageous embodiment, the magnetic sensor elements are mounted on a common rigid body. In this way, the translational and / or rotational movements (i.e., positional displacements) of the sensor elements relative to the conductor are substantially the same for all sensor elements, reducing the computational effort for the processing circuit.

[0109] In some embodiments, a first subset of the sensor elements is mounted on a first rigid body, e.g., a first PCB, and a second subset of the sensor elements is mounted on a second rigid body.

[0110] In some embodiments, signals from one or more of the magnetic sensor elements are combined (e.g., added, subtracted, linearly combined, etc.) and output the gradient of the magnetic field as the field component at each sensor position for a given spatial direction.

[0111] In yet another embodiment, the number of magnetic sensor elements is greater than or equal to the number of multipole components.

[0112] According to yet a further aspect, a current measurement system comprises at least one conductor and a current sensor device according to any of the embodiments disclosed herein for determining a current flowing in the at least one conductor.

[0113] Here too, it should be noted that with respect to the effects and advantages of the above features of the measurement system, the corresponding similar features of the methods and sensor devices disclosed herein are all referred to. Thus, the features of the methods and sensor devices are considered applicable features for defining embodiments of the measurement system, and vice versa, unless otherwise explicitly stated. Therefore, for the sake of brevity of this specification and better understanding of the principles, the description of such similar features, their effects and advantages can be omitted, but such omissions are not to be construed as limitations.

[0114] In some embodiments, the magnetic sensor elements are arranged in a plane oriented perpendicular or parallel to the longitudinal axis of the conductor.

[0115] In a further embodiment, a reference point (also referred to herein as the origin of the multipole expansion) is determined to be in a plane containing the longitudinal axis of the conductor.

[0116] In yet another advantageous embodiment, the magnetic sensor element is arranged along a virtual sensing line around the conductor, the angle range including from 20 to 45 degrees, more preferably from 20 to 90 degrees, and even more preferably up to 180 degrees.

[0117] In some embodiments, the magnetic sensor element is arranged on a PCB oriented perpendicular to the direction of the current flowing through the conductor, and the angle formed between a first leg defined by one of the sensor positions and the geometric center of the cross-section and a second leg defined by another sensor position and the geometric center is at least 20°, or at least 30°, or at least 45°, or at least 60°, or at least 90°, or at least 120°, or at least 150°.

[0118] In yet another embodiment, the magnetic sensor element is arranged along a virtual sensing line around the conductor that extends over an angle range exceeding 180 degrees.

[0119] In yet another advantageous embodiment, the current measurement system comprises two or more conductors, for example three conductors, and the step of determining the current includes determining the individual currents flowing in each of the conductors, and for each of the conductors, a separate multipole expansion is used.

[0120] Further advantageous embodiments are defined in the drawings and the following description.

Brief Description of the Drawings

[0121] These and other features and advantages will become apparent from the following description of non-limiting embodiments, with reference to the drawings.

[0122] The drawings are only schematic, i.e., the sizes of some elements may be exaggerated for the purpose of explanation and may not be drawn to scale. The absolute and relative dimensions do not necessarily correspond to the actual reduction for implementing various embodiments and examples.

[0123] In the figures, schematically: < / t> < / t> < / t>

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0124] In the various figures, equivalent elements with respect to their functions are generally given the same reference number / symbol, usually such that those elements are described only once. DETAILED DESCRIPTION OF THE INVENTION

[0125] When referring to a "conductor" in this specification, an electrically conductive body is meant.

[0126] As used herein, a "magnetic field gradient oriented in a certain direction" means a magnetic field gradient along a direction not specified of a magnetic field component oriented in the specified direction, or a magnetic field gradient along the specified direction of a magnetic field component oriented in a direction not specified.

[0127] As used herein, a "plane of symmetry of a conductor" means the plane of symmetry of the cross-section of the conductor in a plane perpendicular to the direction of the current flow, unless it is clear from the context that something else is meant.

[0128] Next, various embodiments will be described with reference to the drawings.

[0129] Figure 1 schematically shows a cross-sectional view of a conductor 11 (e.g., a long flat bus bar) carrying a current I to be determined according to an exemplary embodiment of the present invention. The method according to the illustrated embodiment is meas - at respective sensor positions <d > with respect to a predetermined reference point (not shown), the magnetic field generated by the current I j meas responsive to a number N s magnetic sensor element HE j (only one of which is shown in FIG. 1) and providing - magnetic sensor element HE j by, at each sensor position <d j >>, the magnetic field the field component, e.g., B x and / or B y and / or B z outputting a sensor signal <s j >; - receiving, by processing circuit 12, a sensor signal <s j from magnetic sensor element HE j >; - mapping, by processing circuit 12 (e.g., an electronic processor, a microcontroller, a microprocessor, a digital signal processor, etc.), the received sensor signal <s j > to an output value representing a current I meas flowing through conductor 11; mapping to TIFF2025097283000039.tif6169; - outputting an output value TIFF2025097283000040.tif6169; and the mapping step is, with respect to the predetermined reference point, the magnetic field meas generated by the current I including using a multipole expansion, the multipole expansion including a predetermined number M m of predetermined multipole components <m α > and respective associated predetermined multipole coefficients c α .

[0130] In some embodiments, the method further includes the additional step of providing a conductor 11.

[0131] As represented by the equation of FIG. 1, the magnetic field is the region of interest 13, i.e., the sensor element HE j M in the area where m Multipole of <m α > is a superposition of the multipole coefficients c α is the magnetic sensor element HE j During the calibration phase, a predetermined calibration current I cal is applied to the conductor 11, and the sensor signal j > is received.

[0132] Sensor element HE j is the magnetic field Any field component, i.e., B x , B y or B z (where the latter is perpendicular to the drawing plane of FIG. 1) can be configured to be detected. In practice, any two spatial field components that do not point in the same direction can be selected as the field components to be detected. It does not necessarily have to be along the coordinate system x, y, z shown in the figure and does not necessarily have to be perpendicular to each other.

[0133] In addition, or alternatively, signals from at least some of the sensor elements HE j in a magnetic field in any spatial direction x, y, or z (where the latter is perpendicular to the drawing plane of FIG. 1) To detect the magnetic field gradient, they can be combined (e.g., addition, subtraction, linear combination, etc.).

[0134] In FIG. 1, the output value is the current I to be determined meas The relative current amplitude γ of, and the translational vector representing the translational displacement between the actual sensor position <d j > and the sensor position during the calibration phase <t>an output vector including is shown as TIFF2025097283000041.tif6169. In this example, the current I to be determined meas is direct current, but is not necessarily limited to this.

[0135] FIG. 2 schematically shows a perspective view of an exemplary embodiment of a sensor device 10 and a current measuring device 30 for determining the current I meas flowing through the conductor 11. This current sensor device 10 includes magnetic sensor elements HE1, HE2, HE3, HE4, HE5, and HE6 that are sensitive to the magnetic field B (see FIG. 1) generated by the current I meas In this embodiment, the number of sensor elements HE1, HE2, HE3, HE4, HE5, and HE6 is six. However, it should be understood that the number shown in FIG. 2 is merely an example, and more or fewer sensor elements HE j may be used in the sensor device.

[0136] In the exemplary sensor device 10 shown in FIG. 2, two sensor elements, namely, HE1 and HE2, HE3 and HE4, HE5 and HE6 are each disposed at substantially the same position <d j >, but they are in two different spatial directions, here for example, in the x and y directions for the magnetic field is detected, but is not necessarily limited to only the x and y directions. As an alternative to the x or y direction, or in addition to the x and y directions, a magnetic field in the z direction It is also possible to detect. Each pair of sensor elements may be packaged, for example, in a single package sensor element such as one SMD package.

[0137] The sensor device 10 further includes a processing circuit 12 configured to receive a sensor signal <s j > from the magnetic sensor elements HE1-HE6. In this sensor device 10, the processing circuit 12 and the sensor elements HE1-HE6 are mounted on a common rigid body, for example, a common printed circuit board (PCB), but are not necessarily limited to this. All of the processing circuit 12 and the sensor elements HE1-HE6 may be mounted on separate bodies (for example, PCBs), or only the processing circuit 12 may be mounted separately from the sensor elements HE1-HE6, and the sensor elements may be mounted together on a common rigid body (for example, a PCB).

[0138] Although not shown, the PCB may further include a non-volatile memory (for example, flash). The non-volatile memory may be embedded in the sensor device or in the processing circuit, or may be a separate component mounted on the PCB, but is communicatively connected to the processing circuit 12.

[0139] In FIG. 2, it is shown that the sensor elements HE1-HE6 are arranged in a plane perpendicular to the longitudinal axis 14 of the conductor 11, corresponding to the cross section of the conductor 11.

[0140] The reference point (not shown), that is, the origin of the multipole expansion, may be determined to be in a plane including the longitudinal axis 14 of the conductor 11 (see FIG. 5), but is not necessarily limited thereto. Generally, the reference point can be selected to be at any spatial position.

[0141] FIG. 3 schematically shows a perspective view of a further exemplary embodiment of a current measurement system 31 using a sensor device 10' similar to that of FIG. 2. The main differences between the measuring device 31 shown in FIG. 3 and the measuring device 30 shown in FIG. 2 are the orientation of the PCB and the position and orientation of the sensor elements HE1-HE6. As can be seen in FIG. 3, the sensor elements HE1-HE6 are arranged in a plane parallel to the longitudinal axis 14 of the conductor 11. As in the example of the current measurement system 30 shown in FIG. 2, in this current measurement system 31, pairs of two sensor elements, namely HE1 and HE2, HE3 and HE4, HE5 and HE6, are magnetic fields in two different spatial directions, for example, the x and y directions is detected. Also, as an alternative to the x or y direction, or in addition to the x and y directions, a magnetic field in the z direction It is also possible to detect. Each pair of sensor elements may be packaged, for example, in a single package sensor element such as one SMD package. Each SMD package may also be called a 2D magnetic pixel.

[0142] Figure 4 schematically shows a cross-sectional view of yet another exemplary embodiment of a current measurement system 32 that uses a sensor device 15 to determine the currents I U meas , I V meas , and I W meas flowing through three conductors 11. In this example, the currents I U meas , I V meas , and I W meas are three-phase alternating current (AC). For each of the conductors 11, a separate individual multipole expansion is used.

[0143] In the example shown in Figure 4, the sensor device 15 includes three sensor elements HE1, HE2, HE3 arranged between the leftmost and the middle conductors 11, and HE4, HE5, HE6 arranged between the middle and the rightmost conductors 11. The sensor elements HE1, HE2, HE3 mainly see the superimposed magnetic field generated by I U meas and I V meas , while the sensor elements HE4, HE5, HE6 mainly see the superimposed magnetic field generated by I V meas and I W meas . To determine the current I V meas , all the signals HE1 to HE6 are used for calculating the output value so that the sensor elements see the magnetic field of I U meas + I V meas and / or I V meas + I W meas .

[0144] The sensor elements HE1, HE2, HE3, HE4, HE5, and HE6, and the processing circuit 12 are arranged in a plane perpendicular to the longitudinal axis of the conductor 11, and the longitudinal axis extends parallel to the z direction in the embodiment shown in FIG. 4. Each of the sensor elements HE1-HE6 is sensitive to a magnetic field in one or more different spatial directions, e.g., the x, y, and / or z directions may be configured to detect.

[0145] FIG. 5 schematically shows a functional diagram of an exemplary embodiment of the sensor device 16. The current I flowing in the conductor 11 meas The sensor device 16 for determining meas the magnetic field generated by the current I responsive to a number N s magnetic sensor element HE j (Of these, HE1 and HE2 are shown in FIG. 5 and there may be more but are not shown), each of the magnetic sensor elements including HE1 and HE2 has a respective sensor position <d j > with respect to a predetermined reference point (not shown but selected to be within the mirror plane 17 including the longitudinal axis of the conductor 11 in this example), for example <d1>and <d2>is arranged at each sensor position <d j > of the magnetic field The sensor signal s indicating the field components, for example Bx and / or By, and / or Bz j (t), that is, s1(t)...s r (t) are each configured to output. In practice, any two spatial field components not in the same direction can be selected as the detected field components. It does not necessarily have to be along the coordinate system x, y, z shown in the figure, and they do not necessarily have to be perpendicular to each other. The sensor device 16 further includes a processing circuit 12 configured to receive the sensor signal s j (t) from the magnetic sensor element HE j (t).

[0146] As shown in FIG. 5, the processing circuit 12 maps the received sensor signal s j (t) to an output value indicating the current I meas flowing through the conductor 11 TIFF2025097283000042.tif6169, and is configured to output its output value TIFF2025097283000043.tif6169. This mapping is based on a predetermined reference point, for the magnetic field meas generated by the current I including using a multipole expansion, which multipole expansion includes a predetermined number M m of predetermined multipole components <m α > and respective associated predetermined multipole coefficients c α .

[0147] The sensor device 16, as described below, uses a Kalman filter approach to generate an output value j (TIFF2025097283000044.tif6169) from the (raw) sensor signal s (t).

[0148] The sensor device 16 comprises a system state corrector 18 configured to determine the actual output value, i.e., the system state, (TIFF2025097283000045.tif6169) of the physical system in a given state update cycle k. The state update cycle k corresponds to a time instant t k such that t k = kT where T is the sampling period. As shown in FIG. 5, in this embodiment, the system state vector (TIFF2025097283000046.tif6169) is the relative current amplitude γ and the translation vector <t>including. Other information, for example, the angular frequency ω and its instantaneous phase φ when determining the AC current as described above, are included in the system state vector can be included in TIFF2025097283000047.tif6169.

[0149] Furthermore, the sensor device 16 shown in FIG. 5 also includes the previous system state in the previous state update cycle k-1 from TIFF2025097283000048.tif6169, and is configured to determine the predicted system state of the physical system in a given prediction cycle k TIFF2025097283000049.tif6169, and includes a system state predictor 19. As shown in FIG. 5, the previous system state from the previous state update cycle k-1 TIFF2025097283000050.tif6169 is provided by the delay unit 20. In a simple implementation, this delay unit can be a memory unit (such as a RAM, register of a μP or μC, etc.) that stores at least one system state TIFF2025097283000051.tif6169 output by the system state corrector 18, and as a result, it can be used as the previous system state TIFF2025097283000052.tif6169 in subsequent state update cycles.

[0150] Furthermore, the sensor device 16 uses a measurement model of the physical system, such as the model described in Equation 7, for example, to obtain the predicted sensor signal in a given prediction cycle k from the predicted system state TIFF2025097283000053.tif6169 TIFF2025097283000054.tif7169, and includes a sensor signal predictor 21 configured to determine it.

[0151] Furthermore, the system state corrector 18 of the sensor device 16 in FIG. 5 corrects the sensor signal s in a given prediction cycle k j The received sensor signal obtained from (t) TIFF2025097283000055.tif6169 and the received sensor signal s j,k The corresponding predicted sensor signal for each of TIFF2025097283000056.tif7169, according to the difference between the predicted sensor signal and the predicted sensor signal, the Kalman filter operation is applied to the predicted system state TIFF2025097283000057.tif6169, by applying the Kalman filter operation to the predicted system state, the actual system state at a given state update cycle k Is configured to be determined

[0152] In this embodiment of the sensor device 16 of FIG. 5, the acquired sensor signal s j,k Is always simultaneously included in the sensor signals s from all the sensor elements HE j That is, each of the acquired sensor signals s j (t) is always simultaneously included, that is, each of the acquired sensor signals s j (t) is related to the same given time instant t at a given prediction cycle k k (also called uniform or simultaneous sampling in this specification). For this purpose, a multi-channel analog-to-digital converter ADC is provided. Each channel of the multi-channel ADC is connected to one of each of the sensor elements HE j To facilitate the simultaneous acquisition of all the sensor signals s j (t). After A / D conversion, the multi-channel ADC outputs the digital representation of the sensor signal s j,k As the acquired sensor signal s j (t)

[0153] In an alternative embodiment (not shown), the sensor device may comprise non-uniform or non-simultaneous sampling of the sensor signal s j (t), in which case the N j For the sensor signal s s The individual channels are multiplexed and discretized in a single-channel ADC to sequentially acquire the signal TIFF2025097283000058.tif8169. The N s Sensor signals s j,k Each of them is used in turn in the prediction and correction step sequences related as described above in the case of the simultaneous sampling approach.

[0154] Although various examples, embodiments, and aspects have been illustrated and described in detail in the drawings and the foregoing description, such illustrations and descriptions should be regarded as exemplary or illustrative and not restrictive.

[0155] Other modifications will be apparent to those skilled in the art from reading this disclosure. Such modifications may include other features that are already known in the art and may be used instead of, or in addition to, the features already described herein.

[0156] Variations to the disclosed embodiments can be understood and achieved by those skilled in the art from a study of the drawings, this disclosure, and the appended claims. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used advantageously.

[0157] Any reference signs in the claims should not be construed as limiting its scope.

Description of the Reference Signs

[0158] 10 Sensor device 11 Conductor 12 Processing circuit 13 Region of interest 14 Longitudinal axis 15 Sensor device 16 Sensor device 17 Symmetry / mirror 18 System state corrector 19 System state predictor 20 Delay unit 21 Sensor signal predictor 30 Current measurement system 31 Current measurement system 32 Current measurement system ADC Analog-to-Digital Converter Magnetic field <d j > Position vector of sensor element j HE j Sensor element I meas Measured current k State update cycle N s Number of sensor elements PCB circuit board TIFF2025097283000059.tif7169 Vector of predicted sensor signals s j (t) Continuous-time sensor signal s j,k Discrete-time sensor signal <t>Translation vector Output value of TIFF2025097283000060.tif6169 Predicted output value of TIFF2025097283000061.tif6169 Previous output value of TIFF2025097283000062.tif6169 Phase 1 of U three-phase AC current Phase 2 of V three-phase AC current Phase 3 of W three-phase AC current First spatial direction x Second spatial direction y Third spatial direction z Relative current amplitude γ Rotation angle θ AC current phase φ AC current angular frequency ω< / t> < / t> < / t> ​ ​​< / c> < / m> < / c> < / m> < / m> < / c> < / m> < / x> < / x>

Claims

1. The current (I meas ), the method comprising: - the respective sensor position (d ｊ ), the current (I meas ) sensitive to a magnetic field (B) generated by a plurality of (N ｓ ) magnetic sensor element (HE ｊ ) providing -Magnetic sensor element (HE ｊ ) to determine the respective sensor positions (d ｊ ) in the magnetic field (B), e.g., field components (B ｘ , B ｙ , B ｚ ) indicating the sensor signal (s ｊ (t) - the magnetic sensor element (HE ｊ ) from the sensor signal (s ｊ receiving by a processing circuit (12) - said processing circuit (12) processes said received sensor signal (s ｊ (t)) flowing through the conductor (11) meas ) output value ( ) - the output value ( ), The mapping step may include determining the current (I meas ), the multipole expansion comprising a predetermined number (M ｍ ) of a given multipole component (m α ) and the associated predetermined multipole coefficients (c α ).

2. The multipole coefficients (c α ) is the sensor position (d ｊ ) evaluated at ｍ ) of the multipole components (m α ) and the received sensor signal (s ｊ (t)) and the right-hand side vector formed by The linear system of equations is determined as a solution vector <c> of the magnetic sensor element (HE ｊ ) of the number (N ｓ ) is the multipole component (m α ) of the number (M ｍ ), the magnetic sensor element (HE ｊ ) of the number (N ｓ ) is the multipole component (m α ) the number (M ｍ ), by the least squares normal equation, and ｊ ) of the number (N ｓ ) is the multipole component (m α ) the number (M ｍ 2. The method of claim 1, wherein if n is less than n, then the solution is solved by selecting the minimum norm solution.

3. The mapping step includes: ｊ ) and each associated multipole coefficient (c α ) weighted by the multipole components (m α ) to find the previous output value ( ) to the predicted sensor signal ( ) as the sensor signal (s ｊ，ｋ ) and predicting the predicted sensor signal ( ) and the received sensor signal (s ｊ ) according to the difference between the output value ( 3. The method of claim 1, further comprising the step of correcting

4. The mapping step may be performed by mapping the sensor positions (d ｊ ) with respect to the sensor position (d ｊ 4. The method of claim 1, further comprising determining an actual translational (t) and / or actual rotational (θ) displacement of the first and second vertices of the first and second vertices of the second and third ...

5. The method according to any one of claims 1 to 4, wherein the reference point is determined to lie in a plane of symmetry (17) of the electrical conductor (11).

6. The sensor position (d ｊ ) is the sensor element (HE ｊ The spatial distance between at least two of the sensor elements (HE ｊ The method according to any one of claims 1 to 5, wherein the maximum operational spatial position change of the relative position between the conductor (11) and the conductor (12) is determined to be greater than the maximum operational spatial position change of the conductor (12).

7. The sensor position (d ｊ 7. The method according to claim 1, wherein the conductor (11) is determined to be located on a plane of symmetry (17) or at a point of symmetry with respect to the plane of symmetry (17) of the conductor (11).

8. The method according to any one of claims 1 to 7, wherein the multipole expansion includes up to second order values.

9. Two or more conductors (11) are provided, and determining the current comprises determining an individual current (I Ｕ meas , I Ｖ meas , I Ｗ meas 9. The method according to claim 1, further comprising determining a multipole expansion for each of the conductors (11), the multipole expansion being determined by a step of:

10. The current (I meas A current sensor device (10, 15, 16) for determining - the current (I meas ) are generated by a magnetic field (B) generated by a plurality of (N ｓ ) magnetic sensor element (HE ｊ ), wherein the magnetic sensor element (HE ｊ ) are determined by the respective sensor position (d ｊ ), and each of the sensor positions (d ｊ The field component (B) of the magnetic field (B) ｘ , B ｙ , B ｚ ) indicating the sensor signal (s ｊ (t)) the magnetic sensor element; - the magnetic sensor element (HE ｊ ) from the sensor signal (s ｊ (t)) a processing circuit (12) configured to receive the The processing circuit (12) processes the received sensor signal (s ｊ (t)) flowing through the conductor (11) meas ) output value ( ), and the output value ( ), and the mapping is configured to output the current (I meas ), the multipole expansion comprising a predetermined number (M ｍ ) of a given multipole component (m α ) and the associated predetermined multipole coefficients (c α ).

11. The magnetic sensor element (HE ｊ 11. The current sensor device of claim 10, wherein the first, second, third and fourth inputs are mounted on a common rigid body (PCB).

12. The magnetic sensor element (HE ｊ ) is a function of the respective sensor position (d ｊ ) in the field component (B ｘ , B ｙ , B ｚ 12. The current sensor device according to claim 10 or 11, configured to output the gradient of the magnetic field (B) as a gradient of the magnetic field (B) and a gradient of the magnetic field (B) as a gradient of the magnetic field (B), respectively.

13. At least one conductor (11) and a current (I) flowing through the at least one conductor (11). meas A current measurement system (30, 31, 32) comprising a current sensor device (10, 15, 16) according to any one of claims 8 to 10 for determining the current.

14. 14. The current measurement system according to claim 13, wherein the reference point is determined to be in a plane (17) containing the longitudinal axis (14) of the electrical conductor (11).

15. and determining the current includes determining an individual current (I) flowing through each of the conductors (11). Ｕ meas , I Ｖ meas , I Ｗ meas 15. The current measurement system according to claim 13 or 14, comprising determining a multipole expansion for each of the conductors (11), wherein a separate multipole expansion is used.

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