Contactless current measurement using magnetic sensors

Abstract

Embodiments of the present disclosure provide a mechanism for measuring current flowing in one or more wires. The mechanism is based on the use of a pair of magnetic sensors arranged in a housing having an opening for the wires, wherein each magnetic sensor pair can generate a pair of signals indicating a magnetic field in two different directions. The output of the sensor pair can be used to derive a measure of the current flowing through one or more wires. The use of a pair of magnetic sensors that can measure the magnetic field in two different directions can simultaneously measure multiple wires placed in the opening, improve the accuracy of current measurement, while relaxing the requirements for precise placement of wires, reducing the effects of stray magnetic interference, and enabling AC and DC measurements.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 62 / 647,044, filed on March 23, 2018, entitled “Contactless Current Measurement Using Magnetic Sensors,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to measuring electric current, and more particularly to apparatus and methods involving measuring electric current flowing through a conductor line using a magnetic sensor. Background Art

[0004] In many applications, such as residential, industrial, and automotive applications, the measurement of current through a conductor performed in a non-contact manner (e.g., without making contact with or breaking contact with the wire) is useful for diagnostic, operational, and protection purposes. Electronic clamp meters and other current measuring devices that use magnetic sensors (e.g., Hall effect sensors) can be used for this purpose. However, current measurement using magnetic sensors presents various challenges. One challenge is achieving accurate measurements without precisely controlling the position of the wire relative to the current measuring device. In addition, accurately measuring the current flowing through a wire can be challenging when there are other current-carrying wires nearby because the current flowing through such wires can interfere with the desired current measurement. Other challenges include making current measurements through multiple wires simultaneously, the ability to perform alternating current (AC) measurements and direct current (DC) measurements, and the ability to provide a current measuring device that is not too large for use in a compact space.

[0005] It would be desirable to develop techniques for contactless current measurement using magnetic sensors that could ameliorate one or more of these challenges. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] To provide a more complete understanding of the present disclosure and its features and advantages, reference is made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, and wherein:

[0007] Figure 1 A block diagram illustrating an example current measurement system according to some embodiments of the present disclosure is provided;

[0008] Figure 2 A block diagram illustrating an example device for measuring current in one or more electrical wires according to some embodiments of the present disclosure is provided;

[0009] Figures 3 to 8 Different examples of arrangements of sensor pairs within an exemplary apparatus for measuring current in one or more electrical wires according to various embodiments of the present disclosure are provided;

[0010] Fig. 9 A flowchart of an example method of operating an apparatus for measuring current through at least one conductor according to some embodiments of the present disclosure is presented;

[0011] Fig.10 A flow chart of an example process for determining a current flowing through at least one conductor according to some embodiments of the present disclosure is presented;

[0012] Figures 11 to 13 shows an exemplary outline along which one or more sensor pairs may be placed, exemplary wires within the outline, and exemplary sensor pairs according to some embodiments of the present disclosure;

[0013] Fig.14A and Fig. 14B providing an example of an arrangement of a first set of sensors and a second set of sensors on different sides of a housing of a current measuring device according to some embodiments of the present disclosure;

[0014] Fig.15 shows an example of a Levenberg-Marquardt operation that may be used with a current measurement process according to some embodiments of the present disclosure; and

[0015] Fig.16 A flow chart of an example process for determining a current through at least one conductive line according to yet another embodiment of the present disclosure is presented. DETAILED DESCRIPTION

[0016] Overview

[0017] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for all of the desirable attributes disclosed herein.The details of one or more implementations of the subject matter described in this specification are set forth in the following description and the drawings.

[0018] Embodiments of the present disclosure provide mechanisms for evaluating current that may flow in one or more wires. In particular, embodiments disclosed herein use magnetic sensors, such as AMR sensors, arranged in a housing of a current measuring device in a specific configuration for contactless measurement of current in one or more wires. An exemplary housing may include an opening for receiving one or more wires to be measured, and the magnetic sensor is located around the opening. During the measurement process, the opening may surround or enclose at least a portion of one or more wires, such as passing a metal wire through the opening. The measurement output of the magnetic sensor can be combined using a nonlinear solution calculation to evaluate the current that may flow through each of the one or more wires. As used herein, "evaluating current" refers to, for example, determining or estimating one or more metrics related to the current, such as the current magnitude, the direction of current flow, and the position (in the opening) of the current-carrying wire being measured for each of the one or more wires provided in the opening.

[0019] The embodiments disclosed herein are particularly advantageous for evaluating current in multi-core cables, such as those used in residential and industrial applications. In a multi-core cable, there may be three conductors: hot, neutral, and ground, and the embodiments disclosed herein allow for the evaluation of current in one or more of these conductors. One of the most commonly used multi-core cables is called a Wire that can be heat resistant, fire resistant, easy to install, and relatively inexpensive. Romex is a common type of wire currently used in single-family residential applications and has been in widespread use over the past 40 years. However, it should be understood that the present disclosure is not specific to Romex wire and can be used to measure other types of multi-core cables. In general, the present disclosure is not limited to 3-wire multi-core cables, and the embodiments disclosed herein can be used to evaluate current in a single wire or a multi-core cable, or simply to evaluate wires that can include two wires, four wires, or any other number of wires.

[0020] In some embodiments, the mechanism disclosed herein uses a pair of magnetic sensors within a housing having an opening for wires, wherein each magnetic sensor pair is capable of generating a pair of signals indicating a magnetic field in two different directions (a first signal in the pair of signals may indicate a magnetic field in a first direction, and a second signal in the pair of signals may indicate a magnetic field in a second direction different from the first direction). A hardware processor that communicates with the magnetic sensor pair may be configured to use the output of the sensor pair to derive one or more measurements related to a current that may flow through one or more wires, such as the magnitude of the current, the direction of the current, or the position of the wire within the opening. Some embodiments are described here using an example in which the first and second directions are perpendicular to each other. However, these descriptions apply to embodiments in which the first direction and the second direction may have any other relationship other than perpendicular to each other, as long as the processor has information about the relationship so that the processor can implement appropriate compensation.

[0021] In some embodiments, the first directions (and second directions, since the second directions have some known relationship to the first directions) of different magnetic sensor pairs are oriented in the same manner relative to some common reference point. However, if this is not the case, the processor can be configured to compensate for differences in the orientations of different magnetic sensor pairs relative to each other and relative to the common reference point. Using magnetic sensor pairs that can measure magnetic fields in two directions, for example, in two directions that are substantially perpendicular to each other, can achieve one or more of the following advantages: allowing currents in multiple wires placed in an opening to be measured simultaneously, reducing the sensitivity of current measurement to the placement of wires in the opening (i.e., improving the accuracy of current measurement while relaxing the requirements for precise control of wire placement), reducing the effects of stray magnetic field interference (such as the earth's magnetic field or the magnetic field of other current-carrying wires near the current measurement device), expanding the measurement range, and enabling AC and DC measurements.

[0022] One aspect of the present disclosure provides a device for measuring a current flowing through at least one wire. The device may include: a housing having an opening for accommodating at least one wire; and a plurality of magnetic sensor pairs and a hardware processor. The plurality of magnetic sensor pairs may be arranged, for example, in the housing (i.e., arranged on the housing or at least partially arranged in the housing), for example, around the housing opening. Each magnetic sensor pair may be configured to generate a signal when at least one wire extends through the opening (e.g., when at least a portion of the wire is located in the opening), the signal including a first signal (e.g., a first voltage or a first current) indicating a magnetic field in a first direction, and a second signal (e.g., a second voltage or a first current) indicating a magnetic field in a second direction. The hardware processor may be configured to derive a measure of a current (a current that may flow) in at least one wire based on signals generated by at least two or more of the plurality of magnetic sensor pairs.

[0023] Other aspects of the present disclosure provide methods for operating such an apparatus and methods for determining a current in at least one conductor.

[0024] As will be appreciated by those skilled in the art, various aspects of the present disclosure, in particular various aspects of current measurement using magnetic sensor pairs proposed herein, may be embodied in various ways, for example, as a method, system, computer program product, or computer-readable storage medium. Thus, aspects of the present disclosure may take the form of a fully hardware embodiment, a fully software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which are generally referred to herein as "circuits," "modules," or "systems." The functions described in the present disclosure may be implemented as algorithms executed by one or more hardware processing units (e.g., one or more microprocessors) of one or more computers. In various embodiments, different steps and portions of steps of each method described herein may be performed by different processing units. In addition, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer-readable media, preferably non-transitory, on which computer-readable program code is embodied (e.g., stored). In various embodiments, such a computer program may be downloaded (updated) to existing devices and systems (e.g., to existing magnetic sensors and / or their controllers, etc.), or stored when these devices and systems are manufactured.

[0025] The following detailed description gives various descriptions of certain embodiments. However, the innovations described herein may be embodied in a variety of different ways, for example, as defined and covered by the claims or selected examples. In the following description, reference is made to the accompanying drawings in which similar reference numerals may indicate identical or functionally similar elements. It will be understood that the elements shown in the drawings are not necessarily drawn to scale. In addition, it will be understood that some embodiments may include more elements than shown in the figures and / or a subset of the elements shown in the figures. In addition, some embodiments may combine any suitable combination of features from two or more of the accompanying drawings.

[0026] Other features and advantages of the disclosure will be apparent from the following description and from the claims.

[0027] Example Current Measurement System / Device

[0028] The current-carrying wire generates a magnetic field in a plane orthogonal to the direction of current flow. The measured value of the magnetic field can be used to infer the magnitude of the current flowing in the wire. For example, a Hall effect sensor can be used to measure the magnetic field using the Lorentz effect, while an anisotropic magnetoresistive (AMR) sensor can measure the magnetic field based on a resistivity change proportional to the perpendicular magnetic field. By using magnetic sensors such as Hall effect sensors and / or AMR sensors, according to various aspects of the present disclosure, certain challenges related to measuring the current through the wire can be overcome. For example, the embodiments described herein can overcome challenges related to magnetic field interference from nearby current-carrying wires. As another example, the embodiments described herein can overcome challenges related to the non-fixed position of the current-carrying wire. Since the magnetic field strength should decrease inversely proportional to the distance from the current-carrying wire, the distance from the wire will have a significant impact on the use of magnetic sensors to infer the current flowing through the wire. In addition, using certain magnetic sensors, such as Hall effect and / or AMR sensors, the device disclosed herein can generate outputs that can be used to accurately perform AC and DC measurements.

[0029] Embodiments disclosed herein propose a current measuring device that can enable the current in multiple conductors placed in an opening to be measured simultaneously. For example, embodiments disclosed herein can implement current measurement of a multi-core cable. In certain embodiments, such a multi-core cable may include a hot wire (which includes a current path flowing out of a current source), a neutral wire (which includes a return path including current), and a bare copper wire (which is a grounding wire connected to the earth). The hot conductor and the neutral conductor typically have opposite current flows, which may cause the magnetic field generated by the two current flows to be offset to at least the first order. Typically, the currents in the hot conductor and the neutral conductor are of the same magnitude. Some residual magnetic field strengths may vary with the spacing between the hot wire and the neutral wire. Since the spacing is unknown and can vary, it may be challenging to use conventional current sensing methods and is generally not feasible. Therefore, there is currently no existing non-contact current sensing solution for multi-core cables.

[0030] In addition, embodiments of the present invention disclose a current measuring device that can expand the measurement area while reducing stray field interference. Therefore, the current of the wire can be measured without accurately positioning the wire and without impact or influence from stray field interference. Advantageously, in some embodiments, by expanding the measurement area of ​​the current measuring device, the wire that cannot be located within a specific point or axis with certainty can be accurately measured during the current measurement process.

[0031] Figure 1 A block diagram is provided that illustrates an example current measurement system 100 according to some embodiments of the present disclosure. Figure 1As shown, the current measurement system 100 may include a current measurement device 102, which may be a mobile current measurement device having a current measurement unit 104. The current measurement unit 104 may include a magnetic sensor pair 106 and a processor 108, such as a hardware processor. The current measurement device 102 may further include a memory 110 and a power supply 112. In some embodiments, the current measurement system 100 may also include one or more of an output device 114, an input device 116, and a network adapter 118.

[0032] The magnetic sensor pair 106 may be a magnetic sensor pair configured to sense a total magnetic field in their vicinity, wherein at least a portion of the magnetic field may be attributed to current flowing through one or more wires placed in a target measurement region of the current measurement unit 104 .

[0033] A magnetic sensor (e.g., an AMR sensor) can sense the strength of a magnetic field in a given direction relative to its internal magnetization. As used herein, the term "magnetic sensor pair" refers to a pair of individual magnetic sensors (e.g., a pair of AMR sensors) that can sense magnetic field strength in two different directions, or to a single magnetic sensor pair (e.g., a single multi-axis AMR sensor) that can sense magnetic field strength in two different directions. The embodiments of the magnetic sensor pair 106 disclosed herein are not limited to AMR sensors, and other types of sensors may be used, including but not limited to giant magnetoresistance (GMR) sensors, tunnel magnetoresistance (TMR) sensors, giant magnetoresistance (CMR) sensors, and extraordinary magnetoresistance (EMR) sensors. In some embodiments, the magnetic sensor pair 106 may include any magnetoresistive (xMR) sensor having a resistance that changes in response to a magnetic field. In some embodiments, the magnetic sensor pair 106 may include a magneto-optical sensor or a superconductor current sensor.

[0034] Each sensor pair 106 can sense magnetic fields in two different directions, thereby generating a pair of signals indicating magnetic fields in different directions: the first signal in the signal pair represents the magnetic field in the first direction, and the second signal in the signal pair indicates the magnetic field in the second direction. For example, in some embodiments, the second direction can be perpendicular to the first direction. As described above, in order to sense magnetic fields in two different directions, each sensor pair 106 may include two separate magnetic sensors (i.e., two separate magnetic sensor circuits), each sensor performing magnetic field measurements in different directions, or a multi-axis sensor pair (i.e., a single magnetic sensor circuit) capable of measuring magnetic fields along multiple axes (i.e., in two (or more) different directions). In the following, the terms "sensor" and "sensor circuit" may be used interchangeably.

[0035] The sensor pair 106 can be positioned in the housing of the current measurement unit 104, particularly around an opening in the housing, which can be considered to define a target measurement area, which will be described in more detail below. In some embodiments shown in the accompanying drawings, the plurality of sensor pairs 106 can include eight sensor pairs. However, the present disclosure is not limited thereto, and in various embodiments, more or fewer sensor pairs 106 can be included in the current measurement device 102. For example, some embodiments may include 4 sensor pairs 106 or 12 sensor pairs 106, as well as other numbers of sensor pairs. The sensor pair 106 can be positioned around the target measurement area, with a distance of multiple distances relative to the center of the target measurement area or a common reference point within the target measurement area, and with multiple orientations relative to a common reference point of the target measurement area, as described in detail below. In addition, in an embodiment where the magnetic sensor pair includes a separate magnetic sensor, such separate sensors can be positioned separately from each other in the housing. For example, some or all magnetic sensors configured to detect a magnetic field in a first direction may be disposed on one side / side of the housing (such sensors may be referred to as "first sensors"), and some or all magnetic sensors configured to detect a magnetic field in a second direction may be disposed on the other side / face of the housing (such sensors may be referred to as "second sensors"). In another example, the first and second sensors may be disposed around the opening in a staggered manner, i.e., one or more first sensors are followed by one or more second sensors, followed by one or more first sensors, and so on, with a certain gap / distance separating the two sensors. For example, such staggered sensors may be disposed around the opening in a circular manner.

[0036] In some embodiments, at least some of the magnetic sensors in the magnetic sensor pairs 106 may include a group of sensors configured as a Wheatstone bridge. For example, each magnetic sensor in the magnetic sensor pairs 106 may include a group of sensors, for example, 4 sensors, configured as a Wheatstone bridge. Configuring these sensors in a Wheatstone bridge creates a magnetic field sensor system whose output voltage is proportional to the magnetic field strength in a given direction. In some embodiments, at least some of the magnetic sensors in the magnetic sensor pairs 106 may include a group of sensors configured as a half-Wheatstone bridge.

[0037] The sensor pair 106 can output voltages proportional to the field strength in two different directions at the location of the sensors. These measured voltages can be provided to the analog front end (in Figure 1 In some embodiments, the signal received from the sensor is conditioned so that the signal can be provided to subsequent circuits, such as an analog-to-digital converter (ADC) (in Figure 1In some embodiments, the conditioned signal may be provided to a multiplexed ADC, which may provide a digital signal corresponding to the field strength in each of the respective directions to a processor 108 (eg, a microcontroller).

[0038] In some embodiments, the processor 108 may execute software or algorithms to perform the activities discussed in this specification, particularly activities related to current measurement using the magnetic sensor pair 106. The processor 108 may be configured to communicatively couple the current measurement unit 104 or the current measurement device 102 to other system elements via one or more interconnects or buses. Such a processor may include any combination of hardware, software, or firmware that provides programmable logic, including but not limited to a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic array (PLA), an application specific integrated circuit (ASIC), or a virtual machine processor. The processor 108 may be communicatively coupled to the memory 110, for example in a direct memory access (DMA) configuration, so that the processor 108 can read from or write to the memory 110. The memory 110 may include any suitable volatile or non-volatile storage technology, including double data rate (DDR) random access memory (RAM), synchronous RAM (SRAM), dynamic RAM (DRAM), flash memory, read-only memory (ROM), optical media, virtual storage area, magnetic or tape storage, or any other suitable technology. Unless otherwise specified, any storage element discussed herein should be interpreted as being included within the broad term "memory". Information measured, processed, tracked, or sent to or from sensor pair 106, processor 108, memory 110, output device 114, or input device 116 can be provided in any database, register, control list, cache, or storage structure, all of which can be referenced in any suitable time frame. Any such storage option can be included in the broad term "memory" used herein. Similarly, any potential processing element, module, and machine described herein should be interpreted as being included within the broad term "processor". Figure 1 Each of the elements shown in FIG. 1 , such as sensor pair 106 and processor 108 , may also include a suitable interface for receiving, transmitting, and / or otherwise communicating data or information in a network environment.

[0039] In certain example embodiments, the mechanisms for contactless current measurement using multiple magnetic sensor pairs as outlined herein may be implemented by logic encoded in one or more tangible media, which may include non-transitory media, such as embedded logic provided in an ASIC, DSP instructions, software (which may include object code and source code) to be executed by a processor or other similar machine. In these cases, some are storage elements, such as Figure 1 The memory 110 shown may store data or information used for the operations described herein. This includes storage elements capable of storing software, logic, code, or processor instructions that are executed to perform the activities described herein. The processor may execute any type of instructions associated with the data or information to implement the operations detailed herein. In one example, the processor, such as Figure 1 The processor 108 shown in the figure can transform an element or item (e.g., data) from one state or thing to another state or thing. In another example, the activities outlined herein can be implemented with fixed logic or programmable logic (e.g., software / computer instructions executed by a processor), and the elements identified herein can be some type of programmable processor, programmable digital logic (e.g., FPGA, DSP, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)), or ASIC including digital logic, software, code, electronic instructions, or any suitable combination thereof.

[0040] The memory 110 may include one or more physical storage devices, such as local memory and one or more mass storage devices. Local memory may refer to random access memory or other non-persistent storage devices that are typically used during the actual execution of program code. The mass storage device may be implemented as a hard drive or other persistent data storage device. The memory 110 may also include one or more cache memories that provide temporary storage of at least some program code in order to reduce the number of times the program code must be retrieved from the mass storage device during execution.

[0041] The power supply 112 can provide Figure 1 In some embodiments, the power source 112 may include one or more battery cells.

[0042] Figure 1Input / output (I / O) devices, depicted as input devices 116 and output devices 114 in the figure, may optionally be included in or coupled to the current measurement device 102. Examples of input devices may include, but are not limited to, keyboards, pointing devices (e.g., mice), etc. Input device 116 may be configured to receive user input, such as when the current measurement starts, what information will be output as a result, and in what format. Examples of output devices may include, but are not limited to, monitors or displays, speakers, etc. In some embodiments, output device 114 may be any type of screen display, such as a plasma display, a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an electroluminescent (EL) display, or any other indicator, such as a dial, a barometer, or an LED. Output device 114 may be configured to show the results of current measurements performed according to the disclosure herein. For example, output device 114 may be configured to provide a graphical user interface and display a graphical representation of the current measured in each wire in the target measurement area, and optionally, the relative position of the measured wires (e.g., relative position relative to each other or relative to a common reference point). In some implementations, the system can include a driver (not shown) for the output device 114. Input and / or output devices can be coupled to the current measurement device 102 or to the current measurement unit 104 directly or through an intervening I / O controller.

[0043] In one embodiment, the input and output devices may be implemented as a combined input / output device (in Figure 1 116 and output device 114). An example of such a combined device is a touch-sensitive display, sometimes referred to as a "touch screen display" or simply a "touch screen." In such an embodiment, input to the device can be provided by movement of a physical object, such as a stylus or a user's finger, on or near the touch screen display.

[0044] A network adapter 118 may also optionally be included in or coupled to the current measurement device 102 to enable it to be coupled to other systems, computer systems, remote network devices, and / or remote storage devices through an intervening private or public network. The network adapter 118 may include: a data receiver for receiving data transmitted to the current measurement device 102 by the system, device, and / or network; and a data transmitter for transmitting data from the current measurement device 102 to the system, device, and / or network. Modems, cable modems, and Ethernet cards are examples of different types of network adapters that can be used with the current measurement device 102.

[0045] In some embodiments, some or all of the memory 110, power supply 112, output device 114, input device 116, and network adapter 118 may reside in the same integrated unit as the sensor pair 106 and processor 108. In other embodiments, one or more of these components / devices may reside in a separate unit from the current measurement unit 104.

[0046] Sensor arrangement example

[0047] Figure 2 A block diagram is provided showing an example device 200 for measuring current in one or more wires according to some embodiments of the present disclosure. The current measurement device 200 may be included as part of the current measurement system 100. For example, the device 200 may include or be included in the current measurement unit 104 of the current measurement system 100. The device 200 may include a plurality of sensor pairs, Figure 2 In the example, the example position (multiple point position) is shown as eight sensor pairs s0, s1, s2, s3, s4, s5, s6 and s7, each sensor pair represents Figure 1 106. In the following, N sensor pairs s0-s N-1 (e.g., eight sensor pairs s0-s7 for the example shown in the figure) will be referred to as sensor pairs 106, where N is an integer equal to or greater than 1, although they may not be labeled with reference numeral 106 in the figure, but only shown as s0, s1, etc., in order to clearly distinguish the individual sensor pairs. Figure 2 (and other figures) show eight sensor pairs, i.e., N=8, but it should be understood that the device 200 (and the sensors of other figures) can include any different number (two or more) of sensor pairs 106. For example, the device 200 can include 4, 6, 10, or 12 sensor pairs, as well as other numbers.

[0048] like Figure 2 As shown, the sensor pair 106 may be disposed within a housing structure (or simply, housing) 202 including an opening 204 having a center 206. The opening 204 is configured to receive one or more current carrying wires on which current measurements are to be performed. Figure 2 The opening 204 is shown as a substantially circular opening, but in other embodiments, the opening 204 may have any other suitable shape, such as an ellipse or a quadrilateral (eg, a rectangle or a diamond). Figure 2204, but the present disclosure is not limited thereto. For example, the housing 202 may form a fork or "V" or "U" shape. In addition, the housing 202 may be capable of opening and closing to enable one or more wires to be inserted into or moved into a target measurement area defined by an opening of the housing structure. For example, line 208 may represent the confluence of two separate arms of the housing 202, such as with a clamp, which may be adjusted to form a gap through which one or more wires may be placed in the opening 204. In another example, line 208 may represent an entry point in the housing 202 for inserting one or more wires into the target measurement area of ​​the opening 204. When the wire is located in the opening 204, the opening 204 and / or the target measurement area may be orthogonal to the length of the one or more wires being tested. Figure 2 An illustration of a conductor 210 to be measured is provided, the conductor being disposed within a target measurement region of opening 204 .

[0049] The opening 204 may define a target measurement area, i.e., an area in which current measurements of the current flowing through the wire may be performed. In some embodiments, the target measurement area may be substantially the same as the opening 204, but may be different in other embodiments. For example, the target measurement area within the opening 204 may vary in size based on the position of the sensor pair 206 relative to the housing 202 and the opening 204. In addition, in some embodiments, a compromise may occur between the size of the target measurement area and / or the amount of stray field interference with the measurement of the current flowing through the wire located within the target measurement area. For example, in some embodiments, the shape of the target measurement area may be substantially circular and may have a radius of 1-5 centimeters (cm), including all values ​​and ranges therein, for example, a radius of 1-2 centimeters. In some other embodiments, the radius of the target measurement area may be less than or less than the radius of the opening 204, or may have a different shape. For example, the shape of the target measurement area within the opening 204 may be an ellipse, an ellipse, or a quadrilateral. In some such cases, housing 202 may form an elliptical area or some other shaped area that is capable of accepting one or more wires or at least partially surrounding the wires to be measured. In contrast to some conventional current measurement devices, the one or more wires measured using device 200 do not need to be positioned at precise X and / or Y coordinate locations to accurately measure the current flowing through the wires, but rather, may be located anywhere within the target measurement area of ​​opening 204.

[0050] Figure 2An embodiment is shown in which sensor pairs 106 are placed at the perimeter of opening 204 along the contour of opening 204. However, in other embodiments, sensor pairs 106 may be disposed at any other location within housing 202 that is suitable for measuring a magnetic field as described herein.

[0051] Figure 2 The device 200 shown is an illustrative example and is not necessarily drawn to scale. Thus, although each sensor pair is shown as being substantially equidistant from the edge of the opening 204 (i.e., shown as being at the edge of the opening 204), in other embodiments, at least some of the sensor pairs may be at a different distance from the edge of the opening 204 than at least some of the other sensor pairs. Distributing the sensor pairs 106 at substantially the same distance from each other along the contour of the opening 204 may result in more uniform measurements.

[0052] like Figure 2 As shown, some sensor pairs s106 may be oriented differently than at least some other sensor pairs 106 . Figure 2 The illustrated illustrations 212 and 214 provide schematic diagrams of two example sensor pairs 106 (i.e., sensor pairs s0 and s2), respectively. As illustrated for these sensor pairs, each sensor pair can be configured to sense a magnetic field in a first direction, as indicated by a dashed arrow, and to sense a magnetic field in a second direction, as indicated by a solid arrow. Magnetic field sensing in two different directions is also illustrated in the illustrations 212 and 214 by showing a light gray first sensor 216 and a dark gray second sensor 218, which indicates that each sensor pair may include a pair of individual sensors 216, 218 that are perpendicularly aligned to each other and configured to measure magnetic fields in the first and second directions described herein. In other embodiments, although a pair of sensors 216, 218 may be shown in this figure and other figures, each sensor pair s may include a single multi-axis sensor that is configured to measure the dashed and solid arrows next to a given sensor pair as shown to measure magnetic fields in the first and second directions. As a result of sensing the magnetic field in the first direction and the second direction, each sensor pair s is configured to generate a first signal (e.g., a first voltage or a first current) indicating the magnetic field in the first direction, and generate a second signal (e.g., a second voltage or a first current) indicating the magnetic field in the second direction. The data processing system of the current measurement system 100, for example, Figure 1 The processor 108 shown in can then be configured to derive a measure of current (potentially flowing) in each conductor of one or more wires placed within the opening 204 based on the first and second signals generated by at least some (e.g., at least two or more) of the plurality of sensor pairs 106.

[0053] The arrangement of the sensor pairs s106 described herein is characterized in that, for each sensor pair 106, the first direction may be substantially perpendicular to the second direction. Figure 2 , where for the two sensor pairs shown with insets 212 and 214 (this also applies to all other sensor pairs of device 200), the first direction (dashed arrows, light gray sensor 216) is substantially perpendicular to the second direction (solid arrows, dark gray sensor 218).

[0054] In addition to the first and second directions being substantially perpendicular for all sensor pairs 106 , how different sensor pairs are oriented relative to each other may vary according to different embodiments of the present disclosure.

[0055] In some embodiments, all sensor pairs 106 may be arranged relative to a common reference point such that for each sensor pair 106, the first direction is substantially perpendicular to a line connecting a sensor reference point (e.g., a magnetic core) of the magnetic sensor pair and the common reference point, and the second direction is substantially parallel to the line. Figure 2 This particular example is shown in Figure 2 The other descriptions provided are equally applicable to embodiments where this is not the case), where the common reference point is assumed to be the center 206 of the circular opening 204, and the first direction (dashed arrow, light gray sensor 216) is substantially perpendicular to a line connecting the sensor reference point 220 (possibly at the intersection of the schematic illustrations of the light gray sensor 216 and the dark gray sensor 218 of each sensor pair), and the second direction (solid arrow, dark gray sensor 218) is substantially parallel to the line for the two sensor pairs shown in illustrations 212 and 214 (and also applies to all other sensor pairs of device 200).

[0056] In other embodiments, at least some of the sensor pairs 106 may adopt an orientation different from that described above, i.e., at least some of the sensor pairs 106 may be arranged differently from this orientation (rotated by a certain angle) relative to the common reference point. In such embodiments, as long as the processor 108 has information about the orientations of the different sensor pairs, and in particular about whether their first directions deviate from being perpendicular to the straight line connecting the sensor reference point and the common reference point and the amount of deviation in the perpendicular direction, or whether their second directions deviate from being parallel to the reference line and the amount of deviation from the second direction (in some embodiments, the processor 108 may only have information about the deviation of one of the first direction or the second direction, because the other is perpendicular), the processor 108 may be configured to calculate and apply compensation for the deviation when deriving a measure of the current flowing through one or more wires in the target measurement area. Since in some embodiments, the orientation of the sensor pairs is likely to be known at design time and set in the final current measurement device, such information may be accessible to the processor 108 by, for example, pre-programmed examples in the memory 110, or by compensation built into the algorithm executed by the processor 108 to derive the magnitude of the current. In other embodiments, the sensor pair 106 may be movable in a direction such that their orientation may change from time to time. In such embodiments, information about their orientation may be accessed by the processor 108 by being provided via the input device 116 or in any other suitable manner.

[0057] Furthermore, in some embodiments, the sensor pairs 106 may be arranged such that the relationship between the first direction (dashed arrows, light gray sensor 216) and the second direction (solid arrows, dark gray sensor 218) may be the same for all sensor pairs. That is, four different examples of such a relationship are possible, as described below.

[0058] In a first example, the “relationship” that maintains the arrangement of each sensor pair 106 may be that the second direction (solid arrow, dark grey sensor 218) points to a common reference point (for Figure 2 In the example shown, the common reference point is the center 206) and the first direction (dashed arrow, light gray sensor 216) is the result of rotating the second direction 90 degrees clockwise. This example can be seen in illustrations 212 and 214 for Figure 2 The example of the device 200 shown (although relative to Figure 2 The other descriptions provided are also applicable to embodiments that are not the case. Figure 3 The sensor arrangement 300 shown in illustrative figures illustrates this example (wherein the first and second measurement directions are indicated for each sensor pair, providing a clear illustration of this example relationship).

[0059] In the second example, for Figure 4 The sensor arrangement 400 shown in FIG. 4 (wherein first and second measurement directions are indicated for each sensor pair) illustrates that the “relationship” maintaining the arrangement of each sensor pair 106 can be such that the second direction (solid arrow, dark gray sensor 218) points to a relative common reference point of the sensor pair, and the first direction (dashed arrow, light gray sensor 216) is the result of rotating the second direction 90 degrees clockwise.

[0060] In the third example, for Figure 5 The sensor arrangement 500 shown in FIG. 1 shows (wherein a first and a second measurement direction are indicated for each sensor pair) that the “relationship” maintaining the arrangement of each sensor pair 106 can be that the second direction (solid arrow, dark gray sensor 218) points to a common reference point relative to the arranged sensor pair, and the first direction (dashed arrow, light gray sensor 216) is the result of rotating the second direction 90 degrees counterclockwise.

[0061] Finally, in a fourth example, not specifically shown in any of the figures, a "relationship" that maintains the arrangement of each sensor pair 106 can be such that the second direction (solid arrow, dark gray sensor 218) points to a common reference point of the sensor pairs relative to their arrangement and the first direction (dashed arrow, light gray sensor 216) is the result of rotating the second direction 90 degrees counterclockwise.

[0062] In other embodiments, at least some of the sensor pairs 106 may adopt different orientations than those described above - that is, the relationship between the first direction and the second direction may be different for different sensor pairs 106. For example, the relationship between the first direction and the second direction of the first sensor pair may be according to the first example of the above four examples (i.e., the second direction points to a common reference point relative to the sensor pair, and the first direction is the result of rotating the second direction 90 degrees clockwise), while the relationship between the first direction and the second direction of the second sensor pair may be according to the second example of the above four examples (i.e., the second direction points to a common reference point relative to which the sensor pair is arranged, and the first direction is the result of rotating the second direction 90 degrees clockwise). In general, the first direction and the second direction of any sensor pair 106 may be in any of the above relationships independently of each other (i.e., some of them may have different relationships and others may have the same relationship). In such an embodiment, as long as the processor 108 has information about the relationship between the first direction and the second direction of each sensor pair whose measurements are used to estimate the measurement of the current in one or more wires, in particular, information about whether one of the first direction or the second direction is clockwise or counterclockwise relative to the other direction, the processor 108 can be configured to calculate and apply compensation for differences in the relationship between the first direction and the second direction of different sensor pairs when deriving a measurement of the current flowing through one or more wires in the target measurement area. Since in some embodiments, the orientation of the first direction and the second direction of different sensor pairs is likely to be known at design time and can be set in the final current measurement device, such information can be accessible to the processor 108 through, for example, pre-programmed examples in the memory 110, or through compensation built into the algorithm executed by the processor 108 to derive the magnitude of the current. In other embodiments, the sensor pairs 106 can be adjustable / reconfigurable because the relationship between their first direction and the second direction can be changed at any time. In such an embodiment, the information about the relationship between their first direction and the second direction can be accessed by the processor 108 by being provided via the input device 116 or in any other suitable manner.

[0063] In even other embodiments, the processor 108 can be configured to apply two compensations when deriving current in one or more conductors, i.e., at least some of the sensor pairs 106 can be arranged differently (rotated by a certain angle) from the same direction relative to a common reference point, as described above, and at least some of the sensor pairs 106 (some of which can but do not necessarily have to be the same as the sensor pair 06 rotated by a certain angle from the same direction relative to the common reference point) can be arranged such that the relationship between the first direction and the second direction can be different for different sensors in these sensor pairs.

[0064] Considerations regarding the placement of the sensor pairs 106, in particular regarding the orientation of the different sensor pairs 106 relative to each other and regarding the relationship between the first and second measurement directions of the respective sensor pairs 106, are discussed in detail below. Figure 3-8 The differences will be explained more clearly in , which shows different, some more general and some specific examples of the above principles.

[0065] Different examples of sensor pair arrangements

[0066] Figures 3 to 8 Different examples of arrangements of sensor pairs 106 within an exemplary apparatus for measuring current in one or more electrical wires according to various embodiments of the present disclosure are provided. Figures 3 to 8 Each of the present invention provides different examples of placement and orientation of sensor pairs 106 within respective current measurement devices and orientation of first and second directions within different sensor pairs 106, such as Figure 2 As shown, for example, sensor pairs s0, s1, s2, s3, s4, s5, s6, and s7 are shown. Unless otherwise specified, the description provided above with reference to device 200 is applicable to Figure 3-8 Each of the above references will not be repeated for the sake of brevity. Therefore, only the differences will be described. Figure 2 The symbols described can be applied to Figure 3-8 In particular, something like Figure 2 ,for Figure 3-8 For each sensor pair 106 shown in , the dashed arrows (or / and light gray rectangles) schematically illustrate a “first direction” of measurements described herein (i.e., the direction may be substantially perpendicular to the direction of a line connecting the sensor reference point (e.g., the magnetic core) of a given magnetic sensor pair and a common reference point common to all sensor pairs), while the solid arrows (or / and dark gray rectangles) schematically illustrate measurements referred to herein as a “second direction” (i.e., the direction may be substantially parallel to the direction of a line connecting the sensor reference point (e.g., the magnetic core) of a given magnetic sensor pair and a common reference point common to all sensor pairs).

[0067] Figure 3 Provides Figure 2 The illustration shown is substantially the same as the illustration shown, except that now also explicitly shows a contour 324 (circular in this example) along which the sensor pair 106 described herein may be moved relative to the Figure 3 The contour line 324 is an imaginary or hypothetical closed contour line along which the sensor pair 106 is positioned and which, according to various embodiments of the present disclosure, may but need not coincide with the edge of an opening for receiving a wire to be tested. Such an opening is Figure 3Shown therein is opening 304 (shown in phantom), which may be similar to opening 204 described above. Figure 3 The opening 304 and the contour 324 are shown as being different but circular, but in some other embodiments, the shapes of the opening 304 and the contour 324 may be different, and in other embodiments, the opening 304 and the contour 324 may also coincide. The contour 324 and the opening 304 together define a target measurement area in which magnetic measurements of the current in one or more wires are to be made. As an example, Figure 3 Two example current carrying wires are shown placed within the target measurement area or opening 304 of the device 300 - a first wire is shown as having a larger cross-section and labeled (I0, z0) to indicate that it carries current I0 and the wire is placed at position z0 within the opening 304, and a second wire is shown as another wire with a smaller cross-section, labeled (I1, z1), indicating that it carries current I1 and the wire is placed at position z1 within the opening 304.

[0068] Figure 3 1 shows an embodiment in which each sensor pair 106 is arranged in the same manner relative to the common reference point 330, i.e., arranged such that for each sensor pair 106, a first direction (dashed arrow, light grey sensor) along which the sensor pair 106 measures the magnetic field to generate a first signal is substantially perpendicular to a line (dashed arrow, light grey sensor) connecting the sensor reference point (e.g., magnetic core) of the magnetic sensor pair and the common reference point 330. Figure 3 The dashed lines in FIG. 3 represent dashed lines between each sensor pair 106 and the common reference point 330. Similarly, for Figure 3 For each sensor pair 106 shown in FIG, a second direction (solid arrows, dark grey sensors) along which the sensor pair 106 measures the magnetic field to generate a second signal is substantially parallel to the line (this is a result of the second direction being perpendicular to the first direction). Figure 3 For all sensor pairs shown in the embodiments, the relationship between the first direction and the second direction is the same. That is, Figure 3 Each sensor pair 106 shown in FIG. 1 is oriented such that the second direction (solid arrows, dark gray sensors) points away from the common reference point 330, the sensor pairs 106 are arranged along the outline 324 relative to the common reference point 330, and the first direction (dashed arrows, light gray sensors) is the direction obtained by rotating the second direction 90 degrees clockwise. In other embodiments, the relationship between the first direction and the second direction of different sensor pairs 106 may be similar to Figure 3 The examples shown vary; in general, it could be any one of the four examples of this relationship described above.

[0069] Figure 4 Shown with Figure 3The embodiment shown is similar to the embodiment shown in which the sensor pair 106 is arranged along the circular contour 404, except that now the common reference point 430 to which the sensor pair 106 is directed is not at the center of the circular contour, which causes the sensors 106 to no longer appear to be Figure 3 Similar to the embodiment of Figure 3 ,for Figure 4 In the illustrated device 400, the contour 424 is an imaginary or hypothetical closed contour along which the sensor pair 106 is placed and which, according to various embodiments of the present disclosure, may but need not coincide with the edge of an opening for receiving a wire to be measured, as shown. Figure 4 The opening shown is opening 404 (shown in phantom), which may be similar to opening 204, as described above. The discussion regarding opening 304 and profile 324 is applicable to opening 404 and profile 424 and, therefore, is not repeated here for the sake of brevity. Figure 4 Also shown are two example current carrying wires (I0, z0) and (I1, z1) placed within the target measurement area or opening 404 of the device 400, showing Figure 3 The examples shown in and described above.

[0070] Even though the common reference point 430 is no longer located at the center of the example circular outline 424, Figure 4 The embodiment also shows that each sensor pair 106 can still be arranged relative to the common reference point 430, so that for each sensor pair 106, the first direction (dashed arrow, light gray sensor) along which the sensor pair 106 measures the magnetic field to generate the first signal can be substantially perpendicular to the line connecting the sensor reference point (e.g., magnetic core) of the magnetic sensor pair and the common reference point 430 ( Figure 4 The dashed lines in FIG. 4 represent dashed lines between each sensor pair 106 and the common reference point 430. Similarly, for Figure 4 Each sensor pair 106 shown in , the second direction (solid arrows, dark grey sensors) along which the sensor pair 106 independently measures the magnetic field to generate the second signal can be substantially parallel to the line (again, a result of the second direction being perpendicular to the first direction). In addition, Figure 4 The illustrated embodiment also shows that Figure 4 For all sensor pairs shown, the relationship between the first direction and the second direction is the same. That is, Figure 4Each sensor pair 106 shown in FIG. 1 is oriented such that the second direction (solid arrow, dark gray sensor) points to the common reference point 430, the sensor pairs 106 are arranged along the outline 424 relative to the common reference point 430, and the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction (i.e., the second example of the above four example relationships) 90 degrees clockwise. In other embodiments, the relationship between the first direction and the second direction of different sensor pairs 106 can be the same as Figure 4 The examples shown vary; in general, it could be any one of the four examples of this relationship described above.

[0071] Figure 4 Provides a Figure 3 Illustration of a more general case, where the common reference point relative to which the various sensor pairs 106 are oriented is any arbitrary point within the opening for receiving the wire. Figure 5 Provides a Figure 4 A more general illustration of the situation, because in Figure 5 In FIG. 5 , the contour 524 along which the sensor pair 106 is located is not circular, but rather has an arbitrary reference shape, and the sensor pair 106 may be arranged in the reference contour 530 relative to the reference point 530. In order not to confuse the figure, Figure 5 The following figures do not specifically illustrate the outline of the opening in the housing of the current measuring device for accommodating one or more wires, however, the considerations provided above regarding the opening and its relationship to the target measurement area and the location of the sensor pair 106 apply to the Figure 5 and each of the subsequent figures. In addition, in order not to confuse the drawings, Figure 5 and subsequent figures do not specifically show the current carrying lines.

[0072] Even though the common reference point 530 is no longer at the center of the example contour 524 and the example contour 524 is no longer a circular contour but a contour of an arbitrary shape, Figure 5 The embodiment of FIG. 5 shows that each sensor pair 106 can still be arranged relative to the common reference point 530 so that for each sensor pair 106, the first direction (dashed arrow, light gray sensor) along which the sensor pair 106 measures the magnetic field to generate the first signal can be substantially perpendicular to a line connecting the sensor reference point (e.g., magnetic core) of the magnetic sensor pair and the common reference point 530 (at Figure 5 5. The dashed line between each sensor pair 106 and the common reference point 530 is shown as a dashed line in FIG. 5. Similarly, Figure 5 For each sensor pair 106 shown in , the second direction (solid arrows, dark grey sensors) along which the sensor pair 106 independently measures the magnetic field to generate the second signal can be substantially parallel to the line (again, this is a result of the second direction being perpendicular to the first direction). In addition, Figure 5The illustrated embodiment also shows that Figure 5 For all sensor pairs shown, the relationship between the first direction and the second direction is the same. That is, Figure 5 Each sensor pair 106 is shown oriented such that the second direction (solid arrow, dark gray sensor) points away from the common reference point 430 relative to which the sensor pairs are arranged along the outline 424, and the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction 90 degrees counterclockwise (i.e., the third example of the above four example relationships). In other embodiments, the relationship between the first direction and the second direction of different sensor pairs 106 can be different. Figure 5 The example shown in is different; in general, it could be any one of the four examples of this relationship described above.

[0073] Figure 6 Provides a Figure 5 As a more general illustration, not only can the contour 624 be any contour, and the common reference point 630 to which each sensor pair 106 is directed can be any point within the opening for receiving the wires, but, Figure 6 The embodiment further illustrates that each sensor pair 106 can be rotated at any angle relative to their arrangement relative to the common reference point 630. For ease of illustration, assume that what was previously referred to as the "first direction" (dashed arrow, light gray sensor), that is, a direction substantially perpendicular to a line connecting the sensor reference point (e.g., magnetic core) of the magnetic sensor pair and the common reference point 630 (at Figure 6 The direction (indicated by the dashed line in FIG. 1 ) between each sensor pair 106 and the common reference point 630 is the “theoretical first direction”. Similarly, since the second direction is perpendicular to the first direction, it is assumed that the second direction previously referred to as the “second direction” (solid arrow, dark gray sensor), that is, substantially parallel to the line connecting the sensor reference point (e.g., magnetic core) of the magnetic sensor pair and the common reference point 630 (i.e., at Figure 6 The direction (shown as a dashed line between each sensor pair 106 and the common reference point 630) is the "theoretical second direction". Figure 6 As shown, in some embodiments, some sensor pairs may be arranged such that their "first directions" (dashed arrows, light grey sensors) are at a non-zero angle α relative to the theoretical first direction. i (where i is an integer between 0 and N, representing a specific sensor pair s i ), or, in other words (since the first and second directions are perpendicular to each other), some sensor pairs can be arranged so that their "second directions" (solid arrows, dark grey sensors) make a non-zero angle α with respect to the theoretical second direction. i . Figure 6An example is shown in which the sensor pairs s3 and s4 are arranged at angles α3 and α4, respectively. In other embodiments, the sensor pairs s3 and s4 may be arranged at any arbitrary angle α3 and α4, respectively. i Arrange any other sensor pairs i .

[0074] It should be noted that the Figure 6 The angle α shown in i An example is provided of how to define the rotation of different sensor pairs 106 relative to the theoretical first and second directions. It is clear from the basic geometry that in various embodiments, the rotation angle can be defined differently, for example, as 360°-α i or 90°-α i As long as the processor 108 has an indication angle α i With information about the first and second orientations (however the rotation angles are defined), for each sensor pair 106, the processor 108 can calculate how the sensor pair measurements need to be compensated for their deviations from the theoretical first and second orientations, and apply this compensation to derive the current measurements.

[0075] and Figure 5 similar, Figure 6 The illustrated embodiment shows that Figure 6 For all sensor pairs shown, the relationship between the first direction and the second direction is the same. That is, Figure 6 Each sensor pair 106 is shown oriented such that the second direction (solid arrow, dark gray sensor) points away from the common reference point 630, relative to which the sensor pairs 106 are arranged along the outline 624, and the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction 90 degrees counterclockwise (i.e., the third example of the four example relationships described above). In other embodiments, the relationship between the first direction and the second direction of different sensor pairs 106 can be different. Figure 6 The example shown in is different; in general, it could be any one of the four examples of this relationship described above.

[0076] Figure 7 Provides a Figure 5 Further illustrating the more general case, not only is the contour an arbitrary contour, but the common reference point targeted by each sensor pair 106 is an arbitrary point within the opening for receiving the wire, and Figure 7 The embodiment also shows that the relationship between the first direction and the second direction in each sensor pair 106 can be different. In particular, Figure 7It is illustrated that the relationship between the first direction (dashed arrow, light gray sensor) and the second direction (solid arrow, dark gray sensor) is the same for some sensor pairs (i.e., sensor pairs s1, s2, s4, s5, s6, and s7), but is different for some other sensor pairs (i.e., sensor pair s0 and s3). Figure 7 The example shows that the orientation of each sensor pair s1, s2, s4, s5, s6 and s7 should make the second direction (solid arrow, dark gray sensor) point away from the common reference point 730, the sensor pairs 106 are arranged along the outline 724 relative to the common reference point, the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction 90 degrees counterclockwise (i.e., the third example of the above four example relationships), the orientation of the sensor pair s0 should make the second direction (solid arrow, dark gray sensor) point to the common reference point 730, the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction (i.e., the fourth example of the above four example relationships) counterclockwise by 90 degrees, the orientation of the sensor pair s3 should make the second direction (solid arrow, dark gray sensor) point away from the common reference point 730, and the first direction (dashed arrow, light gray sensor) is the direction obtained by rotating the second direction (i.e., the first example of the above four example relationships) clockwise by 90 degrees.

[0077] As long as the processor 108 has information indicating the relationship between the first direction and the second direction for each sensor pair 106, the processor 108 can calculate how the sensor pair measurements need to be compensated for their deviations from all having the same relationship, and derive current measurements that employ such compensation.

[0078] Similar to Figure 5 , Figure 7 The embodiment shows that each sensor pair 106 can still be arranged relative to the common reference point 730, so that for each sensor pair 106, the first direction (dashed arrow, light gray sensor) along which the sensor pair 106 measures the magnetic field to generate the first signal can be substantially perpendicular to the line connecting the sensor reference point (e.g., the magnetic core) of the magnetic sensor pair and the common reference point 730, while the second direction (solid arrow, dark gray sensor) along which the sensor pair 106 independently measures the magnetic field to generate the second signal can be substantially parallel to the line (again, this is a result of the second direction being perpendicular to the first direction).

[0079] Figure 8 Provides a diagram of the most general case compared to the other diagrams, similar to Figure 7 , Figure 8 The embodiment of FIG. 1 illustrates that not only is the contour 824 any arbitrary contour, and the common reference point 830 to which each sensor pair 106 is directed is an arbitrary point in the opening for receiving the wire, but also Figure 8The embodiment of FIG. 1 shows that the relationship between the first direction and the second direction can be different in each sensor pair 106. To illustrate this point, Figure 8 The embodiment shows that Figure 7 The relationship between the first direction and the second direction is shown in the example of , that is, each sensor pair s1, s2, s4, s5, s6 and s7 has a first direction and a second direction according to the third relationship, the sensor pair s0 has a first direction and a second direction according to the fourth relationship, and the sensor pair s3 has a first direction and a second direction according to the first relationship. Moreover, similar to Figure 6 , Figure 8 The embodiment also shows that each sensor pair 106 can be rotated at any angle relative to their arrangement relative to the common reference point 830. To illustrate this point, Figure 8 The embodiment shows that Figure 6 The example of different rotations of different sensor pairs shown in FIG. 1 , i.e., the example of sensor pairs s3 and s4 being arranged at angles α3 and α4, respectively. Thus, Figure 8 Can be seen as Figure 6 and Figure 7 Therefore, for Figure 6 and Figure 7 Each of the discussions provided applies to Figure 8 , and will not be repeated here for the sake of brevity.

[0080] As long as the processor 108 has an indication angle α i information (defining the rotation angle in any manner) and information indicating the relationship between the first direction and the second direction for each sensor pair 106, for each sensor pair 106, the processor 108 can calculate the deviation of the sensor pair measurements from the theoretical first direction and the second direction and how their deviations from all directions having the same relationship are compensated, and apply this compensation to derive the current measurement value.

[0081] Despite Figure 2-8 , but in still other embodiments of these figures, the first direction and the second direction of the magnetic field that each sensor pair 106 can measure do not have to be perpendicular to each other. In such embodiments, as long as the processor 108 has information indicating the angle between the first direction and the second direction of each sensor pair 106, the processor 108 can calculate how the sensor pair measurements need to be compensated for their deviations from the first direction and the second direction that are perpendicular to each other, and apply the compensation to derive the current measurement value.

[0082] In addition, despite the Figures 2 to 8Descriptions of various positions and orientations of sensor pairs 106 are provided, showing each sensor pair 106 implemented as a single unit, but these descriptions are equally applicable to the individual magnetic sensors of each sensor pair 106, which are implemented separately and separated from each other by a certain distance, for example, separately on different sides of the shell or in the above-mentioned staggered manner, and separated from each other by a certain distance.

[0083] Example Current Measurement Methods and Procedures

[0084] Fig. 9 A flow chart of an exemplary method 900 of operating a device for measuring current through at least one conductor according to some embodiments of the present disclosure is presented. The method 900 can be implemented using any current measurement system that can measure the amount of current flowing through one or more wires. The method 900 can be implemented in whole or in part using, for example, a mobile current measurement device 102, a current measurement unit 104, one or more processors 108, a sensor pair 106, etc.

[0085] Method 900 may begin at block 902, where one or more wires are placed / enclosed within an opening of current measurement device 102 and within a target measurement zone of current measurement device 102, thereby beginning to measure the current in the wire. In some embodiments, current measurement device 102 may be permanent or fixed to a component that enables continuous or intermittent monitoring of the current in the wire or device, in which embodiments, block 902 need not be repeated for each current measurement. In some such embodiments, process 900 may be performed intermittently or continuously. Block 902 may include enclosing the wire within an opening in a housing of current measurement device 102 such that the wire extends through the opening (i.e., at least a portion of the wire is located within the opening). The wire may be placed substantially perpendicular to the plane of the opening.

[0086] At block 904, multiple magnetic sensor pairs 106 of the current measurement device 102 can be used, while enclosing the wires within the openings, to generate signals indicative of magnetic fields in different directions. In particular, the sensor pairs 106 can be placed in the current measurement device 102 according to any of the above embodiments and oriented between them to generate two signals, respectively: a first signal (e.g., a first voltage or a first current) indicative of a magnetic field in a first direction; and a second signal (e.g., a second voltage or a first current) indicative of a magnetic field in a second direction.

[0087] At box 906, when the wire is enclosed in the opening, the processor of the current measuring device can be used to receive and process the signals generated by the plurality of magnetic sensor pairs. Specifically, the processor 108 can receive the first signal and the second signal generated by at least two or more sensor pairs of all sensor pairs 106, and derive the measure of the current in the wire based on these signals. In various embodiments, the first and second signals of one or more sensor pairs 106 can be subjected to further processing before deriving the measure of the current, such as to filter noise, etc. In box 906, the processor 108 can be configured to calculate and apply compensation as described above, such as compensating for some sensor pairs that deviate from the theoretical first direction and the second direction and / or compensating for some sensor pairs that do not all have the same relationship between their first direction and the second direction.

[0088] Fig.10 A flow chart of an example method 1000 for determining a current through at least one wire according to some embodiments of the present disclosure is presented. The method 1000 can be implemented by any current measurement system that can measure the amount of current flowing through one or more wires. The method 1000 can be implemented in whole or in part using, for example, a mobile current measurement device 102, a current measurement unit 104, one or more processors 108, a sensor pair 106, etc. The method 1000 can be performed in response to a wire being placed in an opening of the current measurement device 102, being placed in a target measurement area of ​​the current measurement device 102, a command from a user, or any other trigger that may initiate a wire current measurement. In some embodiments, the current measurement device 102 can be permanent or fixed to a component that can continuously or intermittently monitor the current in the wire or device. In some such embodiments, the method 1000 can be performed intermittently or continuously. Although many different systems can perform part or all of the method 1000, in order to simplify the discussion, the method 1000 will be described for a specific system.

[0089] Method 1000 begins at block 1002, where a processor, such as processor 108, receives first and second signals from each of at least two magnetic sensor pairs 106 as described herein. The first signal and the second signal can measure a magnetic field in two different directions, namely a first direction and a second direction perpendicular to each other, which can be generated by at least one wire located in an opening of the current measuring device 102. For example, the wire can be a motor control wire, a wire on or connected to a printed circuit board (PCB), or any other type of current-carrying wire. According to Oster's law, a magnetic field can be formed due to current flowing in the wire. Different sensor pairs can generate different first signals and second signals corresponding to different measurements of the magnetic field based at least in part on the distance of the wire from different sensor pairs. In addition, in some cases, stray magnetic field interference may cause two sensor pairs to obtain different measurement results. For a given sensor pair, the measured values ​​of the first signal and the second signal may be different due to different measurement directions.

[0090] At block 1004, the processor 108 may use the sensor measurements to calculate a constant A related to an integral around a contour (e.g., contour 824 or other contours shown) around which the sensor pair 106 is arranged. In particular, the processor 108 may calculate a plurality of contour integrals from which the constant A may be derived.

[0091] For the example where two current lines are within the opening (as shown in some figures), at block 1004, four equations may be used to determine a constant A, which is then used to find the two currents within the opening. For example, the following steps may be followed:

[0092]

[0093]

[0094]

[0095]

[0096] If three wires are placed in the opening, the calculation of block 1004 will require additional equations, in which case the processor 108 will calculate two more constants A (which, along with the four constants above, will result in a total of six equations):

[0097]

[0098]

[0099] This can be further extended to embodiments where more wires are placed within the opening of the current measurement device 102, all of which are within the scope of the present disclosure.

[0100] In each of these equations, as a process for calculating the constant A, the processor 108 calculates integrals around the contour along which the sensor pairs are arranged. These integrals are approximated as finite discrete sums using discrete measurements M(z) received from the sensors and indicating magnetic fields in different directions. In some embodiments, the processor 108 may also use intermediate sensor values ​​obtained by some form of interpolation. In order to calculate the contour integral, the processor 108 needs to determine the value of the integral function around the integral contour. The processor 108 has information about z (where z is the integral variable on the contour) because they are the actual points of the contour. The processor 108 also has information about R(z) because it is the distance from each point z of the contour to a common reference point (in various embodiments, R(z) values ​​can be calculated and pre-stored in a table stored in the memory 110 and accessible by the processor 108, or the processor 108 can be configured to calculate those as part of the algorithm, such as calculating those on the fly). The processor 108 has information about the magnetic field M(z) because it is measured by multiple magnetic sensor pairs 106 located on the contour. More precisely, the processor 108 does not have to have information about M(z) at all points of the profile, but only at a finite number of (i.e., discrete) points where the sensor pair is located. The processor 108 can then use these specific points to approximate the continuous integral with a discrete sum. In some embodiments, the processor 108 can be configured to create / generate more discrete M(z) values ​​by interpolating between existing values ​​(i.e., by interpolating between values ​​at which the sensor pair 106 obtains measurements).

[0101] The path around the fixture (i.e., the path containing all sensor pairs) is integrated. Each value M(z) can be expressed as M(z)=V1(z)+iV1′(z), where V1 is the measurement by a given sensor pair at position z along the first direction (i.e., dashed arrow, light gray; e.g. Figure 2 216 ), and V1′ is a second direction given by the sensor pair at position z (i.e., a solid arrow, dark gray; e.g. Figure 2 R(z) is the distance from the position z where a given sensor pair is placed to a common reference point (e.g., Figure 3 The distance from point 330) shown in FIG.

[0102] Once the processor 108 has calculated A (i.e., the constant A is now known), then in block 1006, the processor 108 may solve a system of equations with two unknowns for each wire within the fixture opening, where the two unknowns are the current value I and the current position z. For example, for Figure 3 and Figure 4 In the example of two wires shown, the two unknowns for the first wire are I0, z0, and the two unknowns for the second wire are I1, z1. Therefore, there will be 2K unknowns for K wires in the opening, and 2K equations will be required, where K is an integer equal to or greater than 1. Continuing with the above example of K=2, this means that there are two wires in the opening, which are four equations to be processed by the processor 108, which will be solved in box 1008 to determine the four unknowns I0, z0, I1, z1 as follows:

[0103] I0+I1=A0

[0104] z0I0+z1I1=A1

[0105]

[0106]

[0107] With three wires extending into the opening (ie, K=3), the equation solved by processor 108 at block 1006 becomes:

[0108] I0+I1+I2=A0

[0109] z0I0+z1I1+z2I2=A1

[0110]

[0111]

[0112]

[0113]

[0114] Therefore, in the case of 3 wires, 6 equations and 6 unknowns (i.e., unknowns I0, z0, I1, z1, I2, z2) can be provided.

[0115] This can be further extended to embodiments in which more wires are placed within the opening of the current measurement device 102, all of which are within the scope of the present disclosure. That is, similar equations can be written for the general case of any number of K-wires, and the solution to the equation (implemented in the processor 108) for the general case of K-wires can be given by:

[0116] make

[0117]

[0118] Among them, as above, Then z0, z1, ..., z K-1 It may be the polynomial p(z)=z K -p1z K-1 -p2z K-2 -...-p K .The root.

[0119] In this manner, measurements along the first and second directions as described herein may be used to calculate a measure of the current (ie, I0, etc.) and the position of the wire within the opening of the current measurement device 102 (ie, z0, etc.).

[0120] Although not in Fig.10 Specific examples are shown in FIG. 1 , but in some embodiments, method 1000 may further include processor 108 calculating and applying appropriate compensation to account for possible changes in the orientation of the sensor pairs and differences in the relationship between the first and second measurement directions, as described herein.

[0121] Example Mathematical Derivation

[0122] Some mathematical derivations will now be explained that may help explain the context of the algorithm implemented by processor 108 to determine the current and position for each wire within the opening of current measurement device 102 .

[0123] Fig.11 An outline 1124 is shown, which is an example of the above outline, within which are placed conductors I0, z0 (i.e., the unknown to be found by processor 108 is the current in the conductor, or any suitable measure of the current, I0 and the position of conductor z0), and an example sensor pair. The above considerations regarding the outline, its relationship to the opening of current measurement device 102, the considerations regarding the sensor pair, etc. apply to Fig.11 (as well as Fig.12 and 13 ) and therefore are not described here for the sake of brevity.

[0124] The two measurements (i.e., the measurement in the first direction and the measurement in the second direction, as described herein) of a single sensor pair located at a distance r1 from the wire, for example a single wire with current I0, are given by,

[0125]

[0126] It may be noted that the above equation may lack a proportionality constant - a combination of the magnetic constant and the sensor's ratio of magnetic measurement units. This constant is known, and the processor 108 may be configured to use this constant as a final scaler to convert the result to whatever current measurement units are being used (A, mA, etc.).

[0127] Fig.12 Provides in complex planes Fig.11 .

[0128] From the basic geometric figures,

[0129] so

[0130] (1)

[0131] Now consider the general case of a pair of sensors located at a common point z on our circle of radius R, and let z0 be the location of the current I0. Let M(z,z0,I0)=V(z,z0,I0)1+iV1′(z,z0,I0) be the magnetic contribution of I0.

[0132] like Fig.13 As shown, Rotation Fig.12 Placing z in R is equivalent to This rotation preserves the relative position of the current flow to the magnetic sensor, so the measurement does not change. Therefore, using equation (1),

[0133] (2)

[0134] Now, suppose we have a magnetic source inside contour 1124 and other magnetic sources outside contour 1124, each contributing to the total measurement with equation (2):

[0135]

[0136] Here z0 is inside the contour 1124, while the other currents are outside the contour.

[0137] Then, according to the Cauchy residual theorem,

[0138] (3)

[0139] With integral around the circle.

[0140] Furthermore, if the first two current positions z0 and z1 are inside the circle, then

[0141]

[0142] (4)

[0143]

[0144]

[0145] We therefore have four equations in four unknowns (this can also be extended to more currents within the contour):

[0146] I0+I1=A0

[0147] (5) z0I0+z1I1=A1

[0148]

[0149]

[0150] Where A0, A1, A2, and A3 are constants calculated from sensor measurements around the contour. These are easy for the processor 108 to solve explicitly (in other embodiments, the processor 108 can also apply various iterative solutions). The next paragraph describes an example derivation of the explicit solutions given previously for the two current cases.

[0151] According to equation (5),

[0152] (z1-z0)I1=A1-z0A0

[0153] z1(z1-z0)I1=A2-z0A1

[0154]

[0155] therefore,

[0156] z1(A1-z0A0)=A2-z0A1

[0157] z1(A2-z0A1)=A3-z0A2

[0158] Due to the symmetry of z0 and z1 in equation (5), they can be exchanged:

[0159] z0(A1-z1A0)=A2-z1A1

[0160] z0(A2-z1A1)=A3-z1A2

[0161] Adding these pairs of benefits

[0162] A1(z0+z1)-2A0z0z1=2A2-A1(z0+z1)

[0163] A2(z0+z1)-2A1z0z1=2A3-A2(z0+z1),

[0164] Right now

[0165] A1(z0+z1)-A0z0z1=A2

[0166] A2(z0+z1)-A1z0z1=A3

[0167] Now, let p1 = z0 + z1 and p2 = -z0z1. Then

[0168]

[0169] z0 and z1 are quadratic polynomials z 2 - Two roots of p1z-p2.

[0170] The above integral implies an infinite number of sensor pairs 106. In practical implementations, the integral is approximated by a finite sum, which implies a finite number of sensors. The number of sensors can be further reduced by interpolating between the sensors.

[0171] The two circular planes of the sensor have a common center and are at a slight angle to each other, allowing currents that are not perpendicular to the plane of the fixture to be resolved as well.

[0172] Recall equation (3) and insert The following content can be obtained:

[0173]

[0174] Because I0 is real

[0175]

[0176] Therefore, in some embodiments, only a single magnetic sensor measurement along a direction tangential to the contour may be required to determine a single current within the fixture and eliminate all currents outside the fixture. However, to solve for multiple currents inside the contour using the method of equation (4), measurements along orthogonal directions are also required for each sensor pair at each point.

[0177] although Figures 11 to 13 The closed contour 1124 is shown as a circle, and the common reference point 1130 is the center of the circle, but as mentioned above, this need not always be the case. Figure 5As shown), an arbitrary point can be chosen inside the contour as the "coordinate center" for calculation purposes. Now, orthogonal pairs of sensor measurement directions are positioned on the contour so that for each sensor pair, one measurement direction is perpendicular to the line connecting the center point of the sensor pair with the chosen common reference point, and the other measurement direction is perpendicular to it. Then, equation (2) still holds, except that R (which is the distance from the sensor to the origin) is now a function of z:

[0178] (6)

[0179] Therefore, the contribution of all currents is (7)

[0181]

[0182] M(z) may not be meromorphic because R(z) may not be meromorphic, however M(z)R(z) is clearly meromorphic, so the same math applies to single or multiple currents in the clamp. For example, equation (3) becomes

[0183] (8)

[0184] Formula (4) becomes

[0185]

[0186] (9)

[0187]

[0188]

[0189] In various embodiments, R(z) may be pre-computed as a table value for each sensor pair and therefore need not be calculated in real time.

[0190] The implementation of the integral formula (4) in a practical application will now be described.

[0191] To this end, return to Figure 5 The example of will be illustrative, which shows a general contour 524 with a general coordinate center 530, where eight pairs of sensors are located at a discrete set of points on the contour. By the definition of the contour integral, the contour can first be parameterized. If the contour is convex, such as Figure 5 As shown in the example of , it can be parameterized as a function of z (i.e. the angle with the real axis):

[0192]

[0193] Then, the first integral of equation (4) becomes

[0194]

[0195] Now we can approximate this integral using eight discrete points measured by the sensor pair, as Figure 5 As shown:

[0196]

[0197] This is simply a weighted sum of eight complex magnetic measurements, where, in some embodiments, the weights can be pre-computed and stored in a small table, such as in memory 110. Similarly, the equation in (4) can be transformed into:

[0198]

[0199] (10)

[0200]

[0201]

[0202] In the more general case, the contour is a circle of radius R, the coordinate center is the center of the circle, and R(z) = R is a constant so its derivative is zero, so equation (5) becomes

[0203]

[0204] (11)

[0205]

[0206]

[0207] The above derivation is shown by way of example only. In practice, more than eight sensor pairs 106 are likely to be required to obtain current measurements with sufficient accuracy (although the processor 108 may be configured to create more sensor pair measurements by interpolating between adjacent sensor pairs).

[0208] Other Examples of Sensor Arrangements and Methods

[0209] As previously mentioned, embodiments disclosed herein may use magnetic sensors, such as AMR sensors, to measure current in one or more conductors in a multi-core cable. Although not limited thereto, assuming that the multi-core cable is a grounded 3-wire cable, and assuming that the ground wire does not carry current, a total of eight variables may need to be determined. In the case where current is also measured in the ground wire, for example due to cable damage, there may be more than eight variables.

[0210] The eight variables include the x, y position of each conductor (e.g., each hot conductor and neutral conductor), the current flowing through each conductor, and the background magnetic field in the x and y directions. The background magnetic field may be caused by the earth's magnetic field and / or the magnetic field from the wires near the current measuring device. In order to determine the values ​​of these eight variables, it is desirable to develop a configuration that places magnetic sensors in a defined manner to produce the best magnetic field solution. One such non-limiting configuration is to place eight magnetic sensors in a circular manner, each of which senses the magnetic field strength in the X direction. These sensors can be placed on a PCB board. Similarly, another eight magnetic sensors can be placed in exactly the same position as the first eight sensors, but at the bottom of the printed circuit board (PCB) and can be oriented to measure the magnetic field strength in the Y direction. At the same time, a pair of such magnetic sensors at each position on the opposite side of the PCB is an example of one of the magnetic sensor pairs 106 described above. This configuration generates 16 data points at eight x, y positions (i.e., eight magnetic sensor pairs 106) where the magnetic field strength can be measured. In some embodiments of one or more such magnetic sensor pairs 106, the location of the sensor used to measure the x-component of the magnetic field and the location of the sensor used to measure the y-component of the magnetic field may be different from each other.

[0211] Fig.14A and Fig. 14B 2 shows an exemplary placement of sensors within an exemplary device for measuring current according to some embodiments. Fig.14A As shown in , the first group of eight sensor circuits can be positioned on one side of the PCB of the current measurement device (e.g., the current measurement device 200 or any other device that can be included as part of the current measurement system 100, such as the current measurement unit 104 of the current measurement system 100), for example but not necessarily on the top side 1400A. The first group of eight sensor circuits can be oriented to measure the magnetic field in the x-direction, respectively. Similarly, as Fig. 14B As shown, the second set of eight sensor circuits can be located on the opposite side of the PCB of the current measuring device, such as but not necessarily the bottom side 1400B. The sensor circuits in the second set of eight sensor circuits can each be oriented to measure the magnetic field in the y direction. Fig.14A and 14B As shown, two example sensor circuits (one in each figure) are enclosed by a dotted line, and another dotted line connects the two sensor circuits, then the sensor circuit on one side 1400A (i.e., the sensor circuit in the first group of sensor circuits) and the corresponding sensor circuit on the other side 1400B (i.e., the sensor circuit in the second group of sensor circuits) together constitute an example of the magnetic sensor pair 106 as described above. Therefore, unless otherwise specified, the description provided above applies to Fig.14A and Fig. 14BArrangement shown.

[0212] In some embodiments, the second set of eight sensor circuits can be orthogonal to the first set of eight sensor circuits. Although as described above, in some embodiments, the first set of sensor circuits and the second set of sensor circuits can be positioned non-orthogonally to each other, positioning the sensor circuits non-orthogonally can increase the complexity of measuring the magnetic field. Fig.14A and Fig. 14B As shown, when the wire is located within the target measurement area of ​​the housing of the current measuring device, the sensor circuit can measure the field strength in the x direction of the coordinate plane and the y direction of the coordinate plane. The wire can extend in the z direction, which points outward from the drawing toward the viewer of the drawing.

[0213] In some embodiments, such as Fig.14A and Fig. 14B As shown, the first set of sensor circuits and the second set of sensor circuits can be located at substantially the same location on the PCB, but on opposite sides. However, in some embodiments, the first set of sensor circuits and the second set of sensor circuits can be located at different locations on the same or different sides of the housing of the PCB. In some embodiments, each sensor circuit can include multiple sensors, such as 4 sensors in a Wheatstone bridge configuration. Therefore, for Fig.14A and 14B For example, there may be 32 sensors on each side of the PCB to measure the x and y components of the magnetic field generated by one or more wires and / or the background field.

[0214] In certain embodiments disclosed herein, the sensor circuit may be symmetrically positioned on the housing / PCB or symmetrically positioned around the target measurement area. In other embodiments, the sensor circuit may be located in various locations to improve or maximize the accuracy of the sensor measurement.

[0215] Sixteen magnetic field measurements may be obtained from the two sets of eight sensor circuits. Each of the sixteen magnetic field measurements may be a non-linear function of the eight variables mentioned previously, e.g., two conductors carrying current, such as a two-wire cable or a three-wire cable with a ground wire (e.g., the x,y position of each conductor with current, the current in each of the two conductors, and the background magnetic field in the x and y directions). Each of the sixteen magnetic sensors in the eight magnetic sensor pairs 106 may be used with an analog front end and ADC to send the field measurements to the processor (block 1402). Fig.14A and 14BThe analog front end, ADC and processor shown in the figure), such as processor 108, processes the measurements as described herein. The ADC can sample the sensor output at a relatively fast rate to provide a continuous data stream from each sensor or sensor circuit. In some embodiments, the processor 108 can use a nonlinear least squares solution technique to extract the values ​​of eight variables from the sixteen magnetic field strength measurements. In addition, in some embodiments, the processor 108 can use a successive approximation method to minimize the error between the sixteen measured field strengths and a set of predicted field strengths predicted based on the predicted x, y position of each conductor, the predicted current of each conductor and the background field. The existence of a local minimum of the error can be based on the fact that the measured values ​​originate from two opposite currents in a multi-core cable or any multiple conductors.

[0216] In some embodiments, processor 108 can use many nonlinear least squares fitting operations to obtain solutions and determine the values ​​of variables. A main indicator may be to use the least time step to achieve the minimum error and converge quickly. One method that processor 108 can be used to obtain a solution is the steepest descent method, which has very good performance in the first few iteration steps, but its final stability may be linear and slow. Another method that processor 108 can use is Newton's method, which is very good in the final stage of the iterative process when the predicted value is close to the solution. Another possible method is to make processor 108 use a mixed operation, which can first use the steepest descent method and then use Newton's method when approaching the final settlement. The challenge of this mixed operation is to develop a robust conversion operation, and the conversion operation will not be too complicated. In other embodiments, processor 108 can use a version of the Dog Leg method of Levenberg-Marquardt method and Powell, or a version of the damped Gauss-Newton method to solve the nonlinear least squares problem. These methods are generally considered to be the best methods for solving the nonlinear least squares fitting problem with the fastest convergence time in such applications.

[0217] Fig.15 Examples of Levenberg-Marquardt operations are presented that can be used with the present measurement process (e.g., method 1600 described below or methods 900 or 1000 described above) for the processor 108 to solve for one or more variables in determining the current in one or more conductors. Combining these nonlinear solvers with contactless current sensing based on magnetic sensor pairs provides a solution for multi-conductor current sensing, for which there are no adequate solutions today.

[0218] Fig.16A flow chart of an example current measurement process 1600 for determining the current flowing through at least one conductor according to yet another embodiment of the present disclosure is shown. The method 1600 can be implemented by any current measurement system that can measure the amount of current flowing through one or more conductors. The method 1600 can be implemented in whole or in part using, for example, a mobile current measurement device 102, a current measurement unit 104, one or more processors 108, a sensor pair 106, etc. The process 1600 can be performed in response to placing a conductor in an opening of the current measurement device 102, being positioned within a target measurement area of ​​the current measurement device 102, a command from a user, or any other trigger that may initiate a wire current measurement. In some embodiments, the current measurement device 102 can be permanent or fixed to a component that can continuously or intermittently monitor the current in a wire or device. In some such embodiments, the method 1600 can be performed intermittently or continuously. Although many different systems can perform part or all of the method 1600, in order to simplify the discussion, the method 1600 will be described for a specific system.

[0219] Method 1600 may begin at block 1602, where, for example, processor 108 determines a projected position of a first wire, a second wire, and a background field. In some embodiments, the first wire and the second wire may be part of a multi-core cable. In other words, in some cases, the first wire may be a hot wire and the second wire may be a In some embodiments, the initial projected position of the first wire and the second wire may be the center of the target measurement area of ​​the current measurement device. In some embodiments, the initial projected position of the first wire and the second wire may be, on average, the center of the target measurement area. Since there are multiple wires, in some cases, both wires may not be located at the center of the target measurement area. Therefore, each of the first wire and the second wire may be offset equally but in opposite directions from the center of the target measurement area so that the average or summed position of the two wires is at the center of the target measurement area.

[0220] At block 1604, the processor 108 may assign a positive current value to the first wire and a negative current value of the same magnitude to the second wire, or vice versa. For example, the current assigned to the first wire may be one ampere (1A) and the current assigned to the second wire may be a negative ampere (-1A).

[0221] At block 1606, the processor 108 measures the magnetic field strength at a set of magnetoresistive sensors using the sensor pairs 106 (e.g., the processor 108 may control the measurement process performed by the sensor pairs 106 and receive the measurement results). In some embodiments, each sensor pair 106 may be used to determine the x, y magnetic field strength at a particular location.

[0222] In box 1608, the processor 108 can calculate the expected magnetic field strength at each sensor based on the projected position of the first wire, the second wire and the background field. In addition, box 1608 can include the processor 108 calculating the expected magnetic field strength based on the current value assigned at box 1604 for the current flowing through the first wire and the second wire. Since the assumed current and position are assigned to each wire, the expected magnetic field strength to be measured by each sensor can be determined. If the assumed current and position of each wire match the actual current and position of each wire, the calculated or expected magnetic field strength should match the measured magnetic field strength determined in box 1606. The difference between the measured and expected magnetic field strength of each sensor can be determined as an error value. In some embodiments, the processor 108 can calculate a separate error value for the magnetic field strength measured at each magnetic sensor. In other embodiments, the processor 108 can determine a total error value or an error value reflecting the total error of the magnetic field strength, for example, by finding a difference between the calculated expected magnetic field strength and the measured magnetic field strength of a group of resistive sensors.

[0223] At decision block 1610, the processor 108 may determine whether the error value between the measured magnetic field strength and the expected magnetic field strength is less than a threshold value. The threshold value may be set by a user or a manufacturer of the current measuring device. In some embodiments, decision block 1610 may include the processor 108 determining whether the error value is at a minimum value or a minimum value. Because the current allocated to the wire as part of block 1604 may not match the actual current in the wire, an error that satisfies the threshold value may not be obtained. However, by determining the point where the error is minimized, the processor 108 may determine the location of the wire within the target measurement area (e.g., the location of a multi-core cable). After determining the location within the target measurement area, the processor 108 may determine the current flowing through the first wire and the second wire based at least in part on the magnetic field strength measured at the determined location. In some embodiments, determining whether the error value is less than the threshold value includes the processor 108 determining the root mean square sum of the errors measured between the output of the sensor and the expected output of the sensor. It can then be determined that the root mean square sum is less than or satisfies the threshold value.

[0224] If the processor 108 determines at decision block 1610 that the error value is not less than the threshold or does not satisfy the threshold, the method 1600 may proceed to block 1612. At block 1612, the processor 108 may adjust the projection position of one or more of the first wire, the second wire, and / or the background field. In some embodiments, the process may then return to block 1606 (e.g., Fig.161606), where the magnetic field strength at each of the set of magnetoresistive sensors is again measured. At box 1608, the processor 108 may recalculate the expected magnetic field strength based on the updated projected position of one or more of the first wire, the second wire, and the background field. Advantageously, in some embodiments, by repeating the process associated with box 1606, movement of the current measuring device during operation (e.g., due to shaking or other movement of the operator's hand) may be taken into account during the measurement process, which may determine the current in one or more wires. Alternatively, in some embodiments, method 1600 may proceed from box 1612 to box 1608, i.e., skipping performing the measurement again (at box 1612). Fig.16 1608 ). In some such embodiments, measured magnetic field strengths previously obtained during execution of method 1600 may be used during execution of decision block 1610 .

[0225] If the processor 108 determines at decision block 1610 that the error value is less than the threshold or does meet the threshold, the method 1600 may proceed to block 1614. At block 1614, the processor 108 may determine the current values ​​of the first and second wires based at least in part on the positions of the first and second wires and the measured magnetic field strength of the set of magnetic sensors 106. In some embodiments, determining the current values ​​of the first and second wires may include repeating a modified version of the method 1600 of the first and second wires within a target measurement area using the known positions determined in an embodiment of the method 1600 while varying the current values ​​applied to the first and second wires. After determining the current value that provides the minimum error, the current value may be displayed or communicated to the user on a display using any type of output device (e.g., output device 114) of the current measurement device 102.

[0226] The description of method 1600 may be extended to any other number of wires and any arrangement of magnetic sensor pairs 106 , all of which are within the scope of the present disclosure.

[0227] Select Examples

[0228] Example 1 provides a device for measuring the current flowing through at least one wire. The device may include a housing having an opening for accommodating the at least one wire. When the wire is located in the opening, the opening may correspond to a target measurement area for measuring the current flowing through one or more wires, such as in a multi-core cable. The device may also include a plurality of magnetic sensor pairs and a hardware processor. The plurality of magnetic sensor pairs may be arranged in the housing (i.e., arranged on the housing or at least partially arranged in the housing), for example, around the opening of the housing. One or more wires may extend in the z direction (when located in the opening), and the plurality of magnetic sensor pairs may be located in one or more xy planes of a three-dimensional coordinate system. Each magnetic sensor pair may be configured to generate a signal when at least one wire extends through the opening (e.g., when at least a portion of the wire is located in the opening), the signal comprising a first signal indicating a magnetic field in a first direction (e.g., a first voltage or a first current) and a second signal indicating a magnetic field in a second direction (e.g., a second voltage or a first current). The hardware processor may be configured to derive a measure of current (current that may flow) in the at least one electrical wire based on signals generated by at least two or more of the plurality of magnetic sensor pairs.

[0229] Example 2 provides the apparatus according to Example 1, wherein for all pairs of magnetic sensors, the first direction is substantially perpendicular to the second direction.

[0230] Example 3 provides a device according to Example 1 or 2, wherein each of the plurality of magnetic sensor pairs is arranged relative to a common reference point so that, for each magnetic sensor pair, the first direction is substantially perpendicular to a line connecting a sensor reference point (e.g., a magnetic core) of the magnetic sensor pair and the common reference point, and the second direction is substantially parallel to the line.

[0231] Example 4 provides an apparatus according to any of the preceding examples, wherein the relationship between the first direction and the second direction is the same for all plurality of magnetic sensor pairs.

[0232] Example 5 provides an apparatus according to Example 4, wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees clockwise.

[0233] Example 6 provides an apparatus according to Example 4, wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees counterclockwise.

[0234] Example 7 provides an apparatus according to Example 4, wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees clockwise.

[0235] Example 8 provides an apparatus according to Example 4, wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees counterclockwise.

[0236] Example 9 provides a device according to Example 1, wherein at least two or more magnetic sensor pairs (i.e., sensor pair signals of which are used to derive a measure of the current in at least one wire) include a first magnetic sensor and a second magnetic sensor. The two magnetic sensors can be arranged relative to a common reference point, so that: for the first magnetic sensor, a first direction of the first magnetic sensor is at a first angle relative to a line connecting a sensor reference point (e.g., a magnetic center) of the first magnetic sensor and the common reference point, a second direction of the first magnetic sensor is substantially perpendicular to the first direction of the first magnetic sensor, and is at a second angle relative to a line connecting the sensor reference point of the first magnetic sensor and the common reference point; for the second magnetic sensor, the first direction of the second magnetic sensor is at a third angle relative to a line connecting a sensor reference point (e.g., a magnetic center) of the second magnetic sensor and the common reference point, a second direction of the second magnetic sensor is substantially perpendicular to the first direction of the second magnetic sensor, and is at a fourth angle relative to a line connecting the sensor reference point of the second magnetic sensor and the common reference point.

[0237] Example 10 provides a device according to Example 9, wherein when the first angle is not equal to the third angle and is not equal to the fourth angle, the hardware processor is configured to compensate for a difference between the first angle and the third angle or compensate for a difference between the first angle and the fourth angle based on signals generated by the first magnetic sensor and the second magnetic sensor before or when deriving a measurement of the current in the at least one wire.

[0238] Example 11 provides a device according to Example 9, wherein when neither the first angle nor the second angle is equal to zero, the hardware processor is configured to compensate for a deviation of a first direction or a second direction of the first magnetic sensor from a line parallel to a sensor reference point connecting the first magnetic sensor and the common reference point before or when deriving a measurement of the current in the at least one wire based on a signal generated by the first magnetic sensor.

[0239] Example 12 provides a device according to Example 11, wherein when the third angle and the fourth angle are both not equal to zero, the hardware processor is configured to compensate for a deviation of the first direction or the second direction of the second magnetic sensor from a line parallel to a sensor reference point connecting the second magnetic sensor and the common reference point before or when deriving a measurement of the current in the at least one wire based on the signal generated by the second magnetic sensor.

[0240] Example 13 provides an apparatus according to any of the preceding examples, wherein the plurality of magnetic sensor pairs are arranged substantially evenly along the imaginary or hypothetical closed contour.

[0241] Example 14 provides a device according to Example 13, wherein the closed contour is substantially circular, elliptical or quadrilateral.

[0242] Example 15 provides the apparatus of any of Examples 1-14, wherein each of one or more of the plurality of magnetic sensor pairs includes a first sensor and a second sensor, the first sensor configured to generate a first signal, and the second sensor configured to generate a second signal.

[0243] Example 16 provides a device according to Example 15, wherein the shell has a first side and an opposing second side, the first magnetic sensor of each of one or more of the plurality of magnetic sensor pairs is disposed on the first side of the shell, and the second magnetic sensor of each of one or more of the plurality of magnetic sensor pairs is disposed on the second side of the shell.

[0244] Example 17 provides an apparatus according to Example 15, wherein for each of one or more of the plurality of magnetic sensor pairs, the first magnetic sensor is separated from the second magnetic sensor by a gap (i.e., the first and second magnetic sensors of each magnetic sensor pair are arranged at a certain distance within the housing).

[0245] Example 18 provides the apparatus of Example 15, wherein first magnetic sensors of the plurality of magnetic sensor pairs are interleaved with second magnetic sensors of the plurality of magnetic sensor pairs.

[0246] Example 19 provides an apparatus according to any of Examples 1-14, wherein each of one or more of the plurality of magnetic sensor pairs comprises a multi-axis sensor.

[0247] Example 20 provides an apparatus according to any of Examples 1-19, wherein the plurality of magnetic sensor pairs comprises Hall effect sensors.

[0248] Example 21 provides an apparatus according to any of Examples 1-19, wherein the plurality of magnetic sensor pairs comprises anisotropic magnetoresistive sensors (AMR).

[0249] Example 22 provides the apparatus of any of Examples 1-19, wherein the plurality of magnetic sensor pairs comprises giant magnetoresistive sensors (GMR).

[0250] Example 23 provides an apparatus according to any of Examples 1-19, wherein the plurality of magnetic sensor pairs comprises tunnel magnetoresistive sensors (TMR).

[0251] Example 24 provides an apparatus according to any of Examples 1-19, wherein the plurality of magnetic sensor pairs comprises magneto-optical sensors.

[0252] Example 25 provides an apparatus according to any of Examples 1-19, wherein the plurality of magnetic sensor pairs includes superconductor current sensors.

[0253] Example 26 provides a device according to any of the preceding examples, wherein the at least one wire is a first wire, each of the plurality of magnetic sensor pairs is configured to generate a signal when both the first wire and the second wire extend through the opening, and the hardware processor is further configured to derive a measure of current in the second wire based on the signals generated by at least two or more of the plurality of magnetic sensor pairs.

[0254] Example 27 provides the apparatus according to Example 26, further comprising a display unit configured to display a graphical representation of the current measurement in the second electrical wire and the current measurement in the first electrical wire derived by the data processing system.

[0255] Example 28 provides a device according to Example 27, wherein the display unit is further configured to display the relative positions of the first wire and the second wire (ie, positions relative to each other or relative to some common reference point).

[0256] Example 29 provides a device according to any of the preceding examples, further comprising an output device configured to display a graphical representation of a measure of current in at least one electrical wire derived by the hardware processor.

[0257] In a further example, the device may include a processor configured to assign a projected position of a first wire and a second wire of one or more conductors (e.g., a multi-core cable) within a target measurement area; calculate expected magnetic field strengths of the first wire and the second wire in the x-direction and the y-direction based at least in part on the projected positions of the first wire and the second wire relative to the first group of sensor circuits and the second group of sensor circuits; use each of the first group of sensor circuits and the second group of sensor circuits described herein to measure (or control a magnetic sensor pair to measure) the magnetic field strength in the x-direction and the y-direction; determine an error value based on the difference between the expected magnetic field strength in the x-direction and the y-direction and the measured magnetic field strength in the x-direction and the y-direction; sequentially adjust the projected positions of the first wire and the second wire until the error value satisfies an error threshold; when the error value satisfies the error threshold and the magnetic field strengths measured in the x-direction and the y-direction, determine the current flowing through the first wire and the second wire based at least in part on the projected positions of the first wire and the second wire.

[0258] In certain other examples, each sensor circuit in the first group of sensor circuits and each sensor circuit in the second group of sensor circuits may include four magnetic sensors configured in a Wheatstone bridge. Alternatively, each sensor circuit in the first group of sensor circuits and each sensor circuit in the second group of sensor circuits may include two magnetic sensors configured in a half-Wheatstone bridge. Each sensor circuit in the first group of sensor circuits and each sensor circuit in the second group of sensor circuits may include one or more AMR sensors. In certain examples, the processor may be further configured to determine the error value by determining the root mean square of the error between the expected magnetic field strength and the measured magnetic field strength relative to each of the first group of sensor circuits and the second group of sensor circuits. In addition, in certain examples, the processor may be further configured to determine whether the error value meets the error threshold by determining whether the root mean square of the error meets the error threshold.

[0259] Example 30 provides a method for operating a device for measuring current flowing through at least one wire. The method may include enclosing the wire in an opening of a housing of the device so that the wire extends through the opening (i.e., at least a portion of the wire is located in the opening), wherein the opening is used to accommodate one or more wires, and the housing includes a plurality of magnetic sensor pairs arranged therein or thereon (e.g., arranged around the opening of the housing); when the wire is enclosed in the opening, using a hardware processor of the device to receive signals generated by the plurality of magnetic sensor pairs, wherein the signals generated by each of the plurality of magnetic sensor pairs include a first signal indicating a magnetic field in a first direction (e.g., a first voltage or a first current), and a second signal indicating a magnetic field in a second direction (e.g., a second voltage or a first current); using the hardware processor to derive a measure of the current in the wire based on the signals generated by at least two or more of the plurality of magnetic sensor pairs.

[0260] Example 31 provides a method according to Example 30, wherein the wire is a first wire, and wherein the method is also used to determine a current in a second wire, the method further comprising: using the opening to enclose a second conductor so that the second wire extends through the opening (for example, at least a portion of the second wire is located within the opening); while both the first wire and the second wire are surrounded by the opening, using the hardware processor to receive signals generated by the multiple magnetic sensor pairs; and using the hardware processor to derive a measure of the current in the second wire based on the signals generated by at least two or more of the multiple magnetic sensor pairs.

[0261] In other examples, the method according to any one of claims 30-31 may further include features for operating a device according to any one of the preceding examples, such as any one of examples 1-29.

[0262] Example 32 provides a method for determining current in a wire, the method comprising arranging a plurality of magnetic sensor pairs in a housing having an opening for accommodating one or more wires to generate a signal when the wire extends through the opening (e.g., when at least a portion of the wire is located within the opening), the signal from each of the plurality of magnetic sensor pairs comprising a first signal (e.g., a first voltage or a first current) indicating a magnetic field in a first direction and a second signal (e.g., a second voltage or a first current) indicating a magnetic field in a second direction; and deriving a measure of the current in the wire based on the signals generated by at least two or more of the plurality of magnetic sensor pairs using the hardware processor.

[0263] Example 33 provides a method for determining a current in a wire, the method comprising receiving signals generated by a plurality of magnetic sensor pairs arranged in a housing having an opening for accommodating one or more wires, wherein the signals are generated when the wires extend through the opening (e.g., when at least a portion of the wires are located within the opening), and wherein the signals from each of the plurality of magnetic sensor pairs include a first signal (e.g., a first voltage or a first current) indicating a magnetic field in a first direction, and a second signal (e.g., a second voltage or a first current) indicating a magnetic field along a second direction; and deriving a measure of the current in the wire based on the signals generated by at least two or more of the plurality of magnetic sensor pairs.

[0264] In further examples, the method according to any of claims 32-33 may further comprise determining a characteristic of a current in a device according to any of the preceding examples, for example, any of Examples 1-29.

[0265] Example 34 provides a device for measuring current flowing through a multi-core cable, the device comprising: a housing including an opening configured to accommodate the multi-core cable; a first magnetic sensor arranged around the opening and configured to measure magnetic field strength in a first direction; a second magnetic sensor arranged around the opening and configured to measure magnetic field strength in a second direction; and a hardware processor configured to determine the current flowing through a single conductor of the multi-core cable based on outputs of the first magnetic sensor and the second magnetic sensor.

[0266] Example 35 provides an apparatus according to Example 34, wherein the processor is further configured to determine a current flowing through a second individual conductor of the multi-core cable based on outputs from the first magnetic sensor and the second magnetic sensor.

[0267] Example 36 provides an apparatus according to Example 34, wherein the first magnetic sensor comprises an anisotropic magnetoresistive sensor.

[0268] Example 37 provides a device according to Example 34, wherein the processor is configured to determine the current flowing through the single wire based on a non-linear operation for calculating the current flowing through the single wire.

[0269] Example 38 provides an apparatus according to Example 34, wherein the processor is configured to determine the current flowing through the single conductor based at least in part on a least squares fitting operation.

[0270] Example 39 provides an apparatus according to Example 34, further comprising an analog front end and an analog-to-digital converter in a signal path between the magnetic sensor of the first magnetic sensor and the processor.

[0271] Example 40 provides an apparatus according to Example 34, wherein the first direction is substantially orthogonal to the second direction.

[0272] Example 41 provides a device according to Example 34, wherein the first magnetic sensor and the second magnetic sensor are disposed within the housing.

[0273] Example 42 provides a device according to Example 34, wherein the first magnetic sensor includes four magnetic sensors.

[0274] Example 43 provides an apparatus according to Example 42, wherein the four magnetic sensors are arranged in a Wheatstone bridge configuration.

[0275] Example 44 provides a device according to Example 34, wherein the processor is configured to determine a current flowing through a single conductor based at least in part on a determination of one or more magnetic field strengths measured by at least some of the first magnetic sensors and the second magnetic sensors, and a determination of a position of the single conductor within a target measurement area.

[0276] Example 45 provides a method for measuring current flowing through a multi-core cable, the method comprising: determining the projected position of a first wire and a second wire of the multi-core cable within a target measurement area; assigning a first expected current value to the first wire, and assigning a second expected current value to the second wire; measuring the magnetic field strength of the magnetic field generated by a first current flowing through the first wire and a second current flowing through the second wire, wherein the magnetic field strength is measured using a set of magnetic sensors arranged around the target measurement area; determining an expected magnetic field strength based at least in part on the projected position of the first wire and the projected position of the second wire; determining an error value based at least in part on the measured magnetic field strength and the expected magnetic field strength; when it is determined that the error value does not meet an error threshold, adjusting the projected position of the first wire; and when it is determined that the error value does meet the error threshold, determining the current value of the first current flowing through the first wire based at least in part on the projected position of the first wire and the magnetic field strength.

[0277] Example 46 provides a method according to Example 45, wherein the multi-core cable includes at least two wires, such as at least three wires.

[0278] Example 47 provides the method according to Example 45, wherein the first predicted current value and the second predicted current value have the same magnitude but opposite phases.

[0279] Example 48 provides a method according to Example 45, wherein the magnetic field is a combination of a first magnetic field generated by a first current flowing through the first wire and / or a second magnetic field generated by a second current flowing through the second wire.

[0280] Example 49 provides the method according to Example 45, further comprising adjusting a projected position of the second electric wire when it is determined that the error value does not satisfy an error threshold.

[0281] Example 50 provides a method according to Example 45, further comprising, when it is determined that the error value does satisfy the error threshold, determining a second current value of a second current flowing through the second wire based at least in part on the projected position of the second wire and the magnetic field strength.

[0282] Example 51 provides a method according to Example 45, wherein the group of magnetic sensors includes a first magnetic sensor and a second magnetic sensor, and wherein the first magnetic sensor is configured to measure the magnetic field strength in a first direction, and the second magnetic sensor is configured to measure the magnetic field strength in a second direction.

[0283] Example 52 provides the method of Example 45, wherein determining a projected position of a first wire and a second wire of the multi-core cable comprises assigning a first default position to the first wire and assigning a second default position to the second wire.

[0284] Example 53 provides the method according to Example 45, further comprising performing a least squares fitting operation to determine a projected position of the first wire at a point where the error value satisfies an error threshold.

[0285] Other implementation notes, variations, and applications

[0286] The principles and advantages discussed herein can be used in any device to measure current flowing through one or more wires. In addition, the embodiments disclosed herein can be used to increase the area or area in which the wire can be located during the measurement of the current flowing through the wire, so that the current in the wire that is awkwardly positioned or blocked by other components can be measured. Further, the embodiments disclosed herein improve the accuracy of current measurement and / or reduce the impact of stray field interference on the current measurement in the wire. The embodiments discussed herein can be implemented to measure current in various systems, including systems related to residential electrical systems, electric vehicles, solar energy, power storage, or other systems where it may be desirable to measure current in one or more wires (e.g., multi-core cables) in a non-contact manner.

[0287] It should be understood that not all objects or advantages may be achieved according to any particular embodiment described herein. Thus, for example, those skilled in the art will recognize that certain embodiments may be configured to operate in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as taught or suggested herein.

[0288] In an example embodiment, the circuits of any number of the accompanying drawings can be implemented on a board of an associated electronic device. The board can be a general circuit board that can accommodate various components of the internal electronic system of the electronic device and can also provide connectors for other peripheral devices. More specifically, the board can provide an electrical connection through which other components of the system can communicate electrically. Any suitable processor (including a digital signal processor, a microprocessor, a supporting chipset, etc.), a computer-readable non-transient storage element, etc. can be appropriately coupled to the board according to specific configuration requirements, processing requirements, computer design, etc. Other components (such as external memory, additional sensors, controllers for audio / video display, and peripherals) can be connected to the board as plug-in cards via cables or integrated into the board. In various embodiments, the functions described herein can be implemented in a simulated form as software or firmware running in one or more configurable (e.g., programmable) elements arranged in a structure that supports these functions. Software or firmware providing simulation can be provided on a non-transient computer-readable storage medium including instructions that allow the processor to perform those functions.

[0289] In another example embodiment, the circuit of the figure can be implemented as a stand-alone module (e.g., a device having associated components and circuits configured to perform a specific application or function), or as a plug-in module into dedicated hardware of an electronic device. Note that specific embodiments of the present disclosure can be easily included in part or in whole in a system-on-chip (SOC) package. SOC represents an IC that integrates the components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed signal, and often radio frequency functions: all of which can be provided on a single chip substrate. Other embodiments may include a multi-chip module (MCM), in which multiple separate ICs are located within a single electronic package and are configured to interact closely with each other through the electronic package. In various other embodiments, the digital filter can be implemented in one or more silicon cores in an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and other semiconductor chips.

[0290] It must also be noted that all specifications, dimensions, and relationships (e.g., number of processors, logical operations, etc.) outlined herein are provided for purposes of example and instruction only. Such information may vary greatly without departing from the spirit of the present disclosure or the scope of the appended claims. These specifications apply only to one non-limiting example, and therefore, they should be interpreted as such. In the foregoing description, example embodiments have been described with reference to a specific arrangement of components. Various modifications and changes may be made to these embodiments without departing from the scope of the appended claims. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

[0291] Note that, with the numerous examples provided herein, interactions can be described in terms of two, three, four or more electronic components. However, this is done only for the purpose of clarity and example. It should be understood that the system can be combined in any suitable manner. Along similar design alternatives, any components, modules and elements shown in the drawings can be combined in various possible configurations, all of which are clearly within the broad scope of this specification. In some cases, it may be easier to describe one or more functions of a given set of processes with reference only to a limited number of electrical components. It should be understood that the drawings and the circuits they teach are easily expandable and can accommodate a large number of components, as well as more complex / complex arrangements and configurations. Therefore, the examples provided should not limit the scope or inhibit the broad teaching of electronic circuits that may potentially be applied to countless other architectures.

[0292] Note that in this specification, references to various features (e.g., elements, structures, modules, components, steps, operations, characteristics, etc.) included in “one embodiment,” “example embodiment,” “embodiment,” “another embodiment,” “some embodiments,” “various embodiments,” “other embodiments,” “alternative embodiments,” etc.) are intended to indicate that any such features are included in one or more embodiments of the present disclosure, but may or may not be combined in the same embodiment.

[0293] It is also important to note that the functions associated with contactless current measurement using magnetic sensors (such as those summarized in one or more processes shown in the figures) illustrate only some of the possible functions that can be performed by or in the current measurement system shown in the figures. Some of these operations may be deleted or removed where appropriate, or the operations may be significantly modified or changed without departing from the scope of the present disclosure. In addition, the timing of these operations may be greatly changed. The above-mentioned operational flows are provided for the purpose of example and discussion. The embodiments described herein provide great flexibility in that any suitable arrangement, timing, configuration, and timing mechanism may be provided without departing from the teachings of the present disclosure.

[0294] Numerous other changes, substitutions, variations, alterations, and modifications may be ascertained by those skilled in the art, and it is intended that the present disclosure encompass all such changes, substitutions, alterations, alterations, and modifications that fall within the scope of the appended claims. Note that all optional features of the above-described apparatus may also be implemented with respect to the methods or processes described herein, and that the details in the examples may be used anywhere in one or more embodiments.

Claims

1. A device for measuring a current flowing through at least one electric wire, the device comprising: a housing including an opening for receiving the at least one wire; A plurality of magnetic sensor pairs arranged along the contour within the housing, each magnetic sensor pair being configured to generate a signal when at least one wire carrying a current extends through the opening, the signal comprising: a first signal indicative of a magnetic field in a first direction, and a second signal indicative of a magnetic field in a second direction; and Hardware processor, configured as: calculating a plurality of constants related to integrals around the contour, wherein the constants are calculated based on signals generated by two or more of the plurality of magnetic sensor pairs; and A measure of the current in the at least one electrical wire is derived based on the constant. The apparatus of claim 1 , wherein the first direction is perpendicular to the second direction.

3. The apparatus of claim 1 , wherein each of the plurality of magnetic sensor pairs is arranged relative to a common reference point such that for each magnetic sensor pair: The first direction is perpendicular to a line connecting a sensor reference point of the magnetic sensor pair and the common reference point, and The second direction is parallel to the line. 4 . The apparatus of claim 3 , wherein the relationship between the first direction and the second direction is the same for all of the plurality of magnetic sensor pairs. 5 . The apparatus of claim 4 , wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees clockwise.

6. The apparatus of claim 4, wherein the relationship between the first direction and the second direction is such that the second direction points away from the common reference point, and the first direction is the second direction rotated 90 degrees counterclockwise.

7. The apparatus of claim 4, wherein the relationship between the first direction and the second direction is such that the second direction points to the common reference point, and the first direction is the second direction rotated 90 degrees clockwise.

8. The apparatus of claim 4, wherein the relationship between the first direction and the second direction is such that the second direction points to the common reference point, and the first direction is the second direction rotated 90 degrees counterclockwise.

9. The apparatus of claim 1 , wherein the two or more magnetic sensor pairs include a first magnetic sensor pair and a second magnetic sensor pair, both arranged relative to a common reference point such that: For the first magnetic sensor pair, the first direction is at a first angle relative to a line connecting a sensor reference point of the first magnetic sensor pair and the common reference point, and the second direction is perpendicular to the first direction and at a second angle relative to a line connecting a sensor reference point of the first magnetic sensor pair and the common reference point, and For the second magnetic sensor pair, the first direction is at a third angle relative to a line connecting a sensor reference point of the second magnetic sensor pair and the common reference point, and the second direction is perpendicular to the first direction and at a fourth angle relative to a line connecting a sensor reference point of the second magnetic sensor pair and the common reference point.

10. The apparatus according to claim 9, wherein: When the first angle is not equal to the third angle and is not equal to the fourth angle, the hardware processor is configured to compensate for a difference between the first angle and the third angle or compensate for a difference between the first angle and the fourth angle before or when deriving a measurement of the current in the at least one wire.

11. The apparatus of claim 9, wherein: When neither the first angle nor the second angle is equal to zero, the hardware processor is configured to compensate for a deviation of the first direction or the second direction of the first magnetic sensor pair from a line parallel to a line connecting a sensor reference point of the first magnetic sensor pair and the common reference point before or while deriving a measurement of the current in the at least one wire.

12. The apparatus of claim 11, wherein: When neither the third angle nor the fourth angle is equal to zero, the hardware processor is configured to compensate for a deviation of the first direction or the second direction of the second magnetic sensor pair from a line parallel to a sensor reference point of the second magnetic sensor pair and the common reference point before or when deriving a measurement of the current in the at least one wire.

13. The device of claim 1, wherein each magnetic sensor pair of one or more magnetic sensor pairs of the plurality of magnetic sensor pairs comprises a first magnetic sensor and a second magnetic sensor, the first magnetic sensor being configured to generate a first signal and the second magnetic sensor being configured to generate a second signal.

14. The apparatus of claim 13, wherein: The housing has a first surface and an opposite second surface, A first magnetic sensor of each magnetic sensor pair of one or more of the plurality of magnetic sensor pairs is disposed on a first face of the housing, and The second magnetic sensor of each magnetic sensor pair of one or more of the plurality of magnetic sensor pairs is disposed on the second face of the housing.

15. The apparatus of claim 1, wherein each magnetic sensor pair in one or more of the plurality of magnetic sensor pairs comprises a multi-axis magnetic sensor.

16. The apparatus of claim 1, wherein: The at least one electric wire is a first electric wire, each magnetic sensor pair of the plurality of magnetic sensor pairs is configured to generate a signal when both the first wire and the second wire extend through the opening, and at least one of the first wire and the second wire carries a current; The hardware processor is further configured to derive a measure of current in the second electrical wire based on a constant. 17 . The apparatus of claim 1 , wherein when the at least one wire comprises K wires, the plurality of constants comprises 2K constants, wherein K is an integer equal to or greater than 1.

18. The apparatus of claim 17, wherein: arranging a plurality of magnetic sensor pairs along the contour relative to a common reference point, The 2K constants are constants A0 to A 2K-1 ,and Based on the contour integral ∮z n-1 M(z)R(z)dz calculates the constant A among the 2K constants n , in: n is an integer between 0 and 2K-1, z is the integration variable over the profile, M(z) is a magnetic field based on signals generated by two or more of the plurality of magnetic sensor pairs, and R(z) is the distance from point z on the contour to the common reference point.

19. The apparatus of claim 16, wherein the hardware processor is further configured to determine, based on the constant, at least one of: the position of the first wire within the opening, and The second electrical wire is positioned within the opening.

20. The device of claim 16, wherein the device further comprises a display unit configured to display a graphical representation of at least one of: a measure of the current in the second wire, and A measure of the current in the first electrical wire.

21. A method of operating a device to measure current flowing through an electric wire, the method comprising: enclosing the wire within an opening of a housing of the device such that the wire extends through the opening, wherein the opening is for receiving one or more wires and the housing includes a plurality of magnetic sensor pairs arranged along a contour in or on the housing; When the wire is enclosed in the opening and carrying current, receiving signals generated by the plurality of magnetic sensor pairs using a hardware processor of the device, wherein the signals generated by each magnetic sensor pair of the plurality of magnetic sensor pairs include a first signal indicative of a magnetic field in a first direction, and a second signal indicative of a magnetic field in a second direction; and Use the hardware processor to: calculating a plurality of constants related to integrals around the contour, wherein the constants are calculated based on signals generated by two or more of the plurality of magnetic sensor pairs, and A measure of the current in the electrical wire is derived based on the constant.

22. A method of determining a current in an electric wire, the method comprising: Arrange a plurality of magnetic sensor pairs along a contour in a housing having an opening for receiving one or more wires to generate a signal when the wires extend through the opening and carry a current, the signal from each magnetic sensor pair comprising: a first signal indicative of a magnetic field in a first direction, and a second signal indicative of a magnetic field in a second direction; and Use the hardware processor to: calculating a plurality of constants related to integrals around the contour, wherein the constants are calculated based on signals generated by two or more of the plurality of magnetic sensor pairs, and A measure of the current in the electrical wire is derived based on the constant.

23. A device for measuring current flowing through a multi-core cable, the device comprising: a housing including an opening configured to receive a multi-core cable; a first magnetic sensor arranged around the opening along a contour and configured to measure a magnetic field strength in a first direction; a second magnetic sensor arranged around the opening along the contour and configured to measure the magnetic field strength in a second direction; and The processor is configured as: calculating a plurality of constants related to integrals around the contour, wherein the constants are calculated based on outputs of the first magnetic sensor and the second magnetic sensor, and A current in at least one conductor of the multi-core cable is determined based on the constant.

24. The apparatus of claim 23, wherein the first direction is substantially orthogonal to the second direction.

25. The apparatus of claim 23, wherein the first magnetic sensor comprises four magnetic sensors, and wherein the four magnetic sensors are arranged in a Wheatstone bridge configuration.

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