Current sensor system

Abstract

The present disclosure relates to a current sensor (1600) for measuring a current. In one example, the current sensor comprises a first part (1510) comprising a first measurement coil (1530) and a second part (1520) comprising a second measurement coil (1540). A conductor (1550) is wound multiple times around the first part. The first part and the second part are then positioned relative to each other such that the first measurement coil and the second measurement coil at least partially encircle at least two portions of the conductor.

Description

Related applications

[0001] This application claims the priority benefit of U.S. Patent Application No. 18 / 581219, filed February 19, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to a current sensor for measuring current in a conductor, and more specifically to a system using at least two parts and a conductor. Background Technology

[0003] Current sensors detect and measure the current flowing through a conductor. They are used in many different applications, such as providing accurate current measurements in electricity meters.

[0004] One type of current sensor uses a shunt resistor connected in series with the current-carrying conductor. The voltage drop across the resistor can be measured, and the current flowing through the resistor can be calculated based on its known resistance value. However, at higher currents, the temperature of the shunt resistor may rise, altering its resistance and thus leading to inaccurate current measurements. Furthermore, since the shunt resistor is directly in the path of the measured current, isolation circuitry may be necessary between the shunt resistor and the sensitive measurement and processing electronics.

[0005] Another type of current sensor uses an electromagnetic transducer to detect changes in the magnetic field generated by a current-carrying conductor. These rate-of-change current sensors (sometimes called di / dt current sensors), such as Rogowski coils, do not require any physical connection to the current-carrying conductor and therefore do not require any additional isolation components to isolate them from the conductor.

[0006] Rate-of-change current sensors can be implemented on printed circuit boards (PCBs), for example, by forming coils on two layers of the PCB using metal traces and vias. The metal traces and vias can together form a helical conductor that forms a loop shape to surround an opening in the PCB through which a current-carrying conductor can pass.

[0007] One type of rate-of-change current sensor is the clamp-on sensor. This type of sensor is designed to be mounted onto an in-situ current-carrying conductor, allowing the conductor to be positioned within the central opening of the current sensor. Such clamp-on sensors typically have a sensor coil divided into two parts, with a gap in the coil to allow the current-carrying conductor to pass through this gap into the central opening of the sensor. Typically, the current sensor is designed such that when the conductor has passed through the gap in the sensor and is positioned within the central opening, the two parts of the coil can be closed and clamped together, effectively forming a single coil that surrounds (or encloses) the conductor. In an example of a rate-of-change current sensor implemented on a PCB, each of the two parts of the coil can be formed on a separate PCB, and then these PCBs are closed together around the current-carrying conductor.

[0008] Each part of a clamp sensor is typically electrically connected together passively, for example, via wires and / or connectors, so that the two parts of the coil can electrically form a single coil. The signal from one part is added to the signal from the other part to form a combined signal that represents the rate of change of current carrying the conductor being measured by the coil. Optionally, the current can be determined by integrating the rate of change signal. However, these wires and connectors can introduce asymmetry and irregularities, forming undesirable loops in the effectively combined coil, resulting in poor electromagnetic field suppression, poor electrostatic coupling, and / or crosstalk with adjacent current sensors or other devices. Therefore, the performance of such clamp sensors can be poor. Summary of the Invention

[0009] In a first aspect, a current sensor is provided, comprising: a first portion including a first measuring coil; a second portion including a second measuring coil; and a conductor for carrying a current measured by the current sensor, the conductor being wound multiple times around the first portion, wherein the first portion and the second portion are configured to be positioned relative to each other such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor.

[0010] In a second aspect, a current sensor is provided, comprising: a first portion including: a first measuring coil; a first electronic circuit including a first input terminal coupled to the first measuring coil and a first output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil; a second portion including: a second measuring coil; a second electronic circuit including a second input terminal coupled to the second measuring coil and a second output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil; and a conductor for carrying a current measured by the current sensor, the conductor being wound multiple times around the first portion such that the conductor passes multiple times between the first measuring coil and the second measuring coil.

[0011] In a third aspect, a method for mounting a current sensor is provided, the method comprising: winding a conductor for carrying a current measured by the current sensor around a first portion of the current sensor multiple times, the first portion including a first measuring coil; and positioning a second portion of the current sensor relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor.

[0012] In a fourth aspect, a method for mounting a current sensor is provided, the method comprising: positioning a pre-wound conductor comprising a plurality of turns for carrying a current measured by the current sensor above a first portion of the current sensor, the first portion including a first measuring coil; and positioning a second portion of the current sensor relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor for carrying the current.

[0013] In a fifth aspect, a method for manufacturing a conductor for a current sensor is provided, the method comprising: winding the conductor around a molding die such that the conductor forms a coil comprising a plurality of turns, wherein the molding die is shaped such that the coil is used to fit over a first portion of a current sensor; and removing the conductor from the molding die.

[0014] In a sixth aspect, a component kit for a current sensor is provided, the component kit comprising: a first portion including a first measuring coil; a second portion including a second measuring coil; and a conductor for carrying a current measured by the current sensor, wherein the conductor for carrying the current is wound to form a plurality of turns, and wherein the first portion and the second portion are configured for positioning relative to each other and the conductor such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor. Attached Figure Description

[0015] Various aspects of this disclosure are described by way of example only with reference to the following figures, in which:

[0016] Figure 1 This is a schematic diagram of a known Rogowski coil;

[0017] Figure 2A A first example of a PCB-implemented clamp current sensor is shown;

[0018] Figure 2B It shows from different perspectives Figure 2A Clamp-on current sensor;

[0019] Figure 2C It shows Figure 2A and Figure 2B Alternative implementations of clamp-on current sensors;

[0020] Figure 2D It shows Figure 2A An exemplary schematic circuit diagram of a clamp-on current sensor;

[0021] Figure 3 An exemplary schematic diagram of a system according to one aspect of this disclosure is shown;

[0022] Figure 4 It shows Figure 3 A schematic diagram of an alternative implementation of the system;

[0023] Figure 5 It shows Figure 3 An exemplary schematic circuit diagram of the system;

[0024] Figure 6 Explanation is shown Figure 5 An exemplary schematic circuit diagram detailing an exemplary implementation of the circuit;

[0025] Figure 7 Explanation is shown Figure 5 Exemplary schematic circuit diagrams detailing alternative exemplary implementations of the circuit;

[0026] Figure 8An exemplary embodiment of an electricity meter according to one aspect of this disclosure is shown;

[0027] Figure 9 An exemplary schematic diagram of a system according to another aspect of this disclosure is shown;

[0028] Figure 10 An exemplary schematic diagram of a system according to another aspect of this disclosure is shown;

[0029] Figure 11 An exemplary schematic diagram of a system according to another aspect of this disclosure is shown;

[0030] Figure 12 An exemplary schematic diagram of a system according to another aspect of this disclosure is shown;

[0031] Figure 13a An example of a current sensor implemented on a PCB, comprising a single conductor, is shown.

[0032] Figure 13b An example of a current sensor implemented on a PCB, including three conductors, is shown;

[0033] Figure 14a The first stage of the winding of a current sensor implemented by passing a conductor through a PCB is shown;

[0034] Figure 14b The second stage of the winding of a current sensor implemented by passing a conductor through a PCB is shown;

[0035] Figure 14c The third stage of the winding of a current sensor implemented by a conductor passing through a PCB is shown;

[0036] Figure 14d The fourth stage of the winding of a current sensor implemented by a conductor passing through a PCB is shown;

[0037] Figure 15a An example of a split-type coil or clamp-on current sensor is shown;

[0038] Figure 15b The first part of a split-type coil current sensor is shown;

[0039] Figure 15c The second part of the split-type coil current sensor is shown;

[0040] Figure 16a The first stage of winding a conductor through a split-coil PCB is shown;

[0041] Figure 16b The second stage of the winding of a current sensor implemented by a split-coil PCB is shown;

[0042] Figure 16c The third stage of the winding of a current sensor implemented by passing a conductor through a split-coil PCB is shown;

[0043] Figure 16d The fourth stage of the winding of a current sensor implemented by passing a conductor through a split-coil PCB is shown;

[0044] Figure 16e The image shows two parts of a split-type coil current sensor surrounding a conductor assembly;

[0045] Figure 17a The pre-wound conductor is shown;

[0046] Figure 17b The first stage of positioning a pre-wound conductor above the first part of a split-coil current sensor is shown.

[0047] Figure 17c The second stage, in which a pre-wound conductor is positioned above the second part of a split-coil current sensor, is shown.

[0048] Figure 17d The image shows two parts of a split-type coil current sensor surrounding a pre-wound conductor assembly. Detailed Implementation

[0049] Split-type or clamp-on rate-of-change current sensors allow for mounting the current sensor around a conductor, which may not be possible with non-split-type current sensors, but this approach has several drawbacks. The main drawback is reduced measurement accuracy due to defects / asymmetries in the mounted coil and electromagnetic noise induced in the electrical interconnections between the two parts of the current sensor coil and between the two parts of the current sensor coil and the current measurement circuit, which uses the signal output from the current sensor coil to determine the current measurement. Furthermore, this increases manufacturing and installation costs and complexity because the two parts of the coil need to be electrically connected together, requiring additional components and tighter manufacturing tolerances to ensure that the two parts are electrically connected in an accurate positional relationship and to introduce a minimal amount of additional looping, thus avoiding the pickup of unwanted magnetic fields.

[0050] To address these issues, the inventors have developed a split-type or clamp-on current sensor, wherein each part of the current sensor has active electronic circuitry to process the signal output from that part. For example, if the sensor is divided into two measuring coils, the first measuring coil has a first electronic circuitry that processes the sensor signal output from the first measuring coil before it is sent to the current measuring circuit. The processing may include at least one of the following: signal amplification; analog-to-digital conversion; voltage-to-current conversion.

[0051] The result is that the signal is less susceptible to electromagnetic noise pickup (e.g., stray electromagnetic fields from adjacent unrelated conductors), which should improve the signal-to-noise ratio and integrity of the signal received by the current measurement circuit, thereby improving the accuracy of the current measurement. This can be particularly effective when the first electronic circuit is located close to the first measuring coil, minimizing electromagnetic noise pickup in the conductor between the measuring coil and the electronic circuit. A similar second electronic circuit can be used for the second measuring coil. The outputs of the two electronic circuits can then be combined to effectively form a larger virtual coil for measuring the current in the conductor, wherein the two coils together at least partially wrap around the conductor, each contributing to the measurement of the current in the conductor. The larger virtual coil is formed in such a way that the two coils are not passively connected together to form a single conductive coil (as in the previous design, where the current in the current-carrying conductor is measured by measuring the output of that coil). Instead, the independent signal outputs of the active circuits are combined such that the combined signal substantially corresponds to the signal output by the larger coil formed by the two separate coils.

[0052] Before signals are transmitted to where they will be combined (e.g., at the measurement circuitry), they are amplified by active circuitry, which reduces the input equivalent noise of any electromagnetic noise subsequently picked up in the conductors and connectors carrying the signals. For example, if the gain in the active circuitry is 30, the same interconnect loop will pick up the same electromagnetic noise as in a passive coupling design, but the signal will be amplified 30 times, thus increasing the relative signal-to-noise ratio by 30 times. Analog-to-digital conversion is performed by active circuitry before signals are transmitted to where they will be combined, meaning that when the signals are transmitted, they are in a form that should be virtually immune to electromagnetic pickup. Voltage-to-current conversion is performed by active circuitry before signals are transmitted to where they will be combined (e.g., at the measurement circuitry), meaning that any EMF voltage subsequently picked up in the conductors and connectors carrying the signals should not affect the transmitted current signal on the first order. These are just some examples of active processing that can be performed to reduce sensitivity to noise. Other means of actively processing signals picked up by coils can also be used to reduce sensitivity to noise pickup in the conductors carrying the signals.

[0053] Active processing signals from each coil can be combined at multiple different locations. For example, an active processing signal from one coil can be transmitted via a conductor to the location of the active circuitry of another coil and combined there. Alternatively, active processing signals from two coils can be transmitted separately via corresponding conductors to a third location, such as a processor containing circuitry for receiving and combining signals, upstream of a signal measurement circuit configured to measure the combined signal.

[0054] The combined signals can be achieved through summation, and can be weighted or unweighted (i.e., applying different amounts of gain to the coil signals via appropriate active circuitry, or not applying different amounts of gain). For example, weighting can be applied to at least partially correct for differences in signal strength between each coil and / or processing path. Applying weighting can support intentionally designing the coils differently (e.g., different sizes), or it can be used to correct for inconsistencies that lead to undesirable errors. For example, in the prior art where two coils are passively connected to form a single coil, if the coils should be matched but are actually mismatched, one part of the coil will be more sensitive than the other, meaning that if the position of the current-carrying conductor changes relative to each part of the coil, subsequent errors will occur in the measurement.

[0055] In this disclosure, the combination of active processing signals from each coil can occur in either the analog or digital domain. In the analog domain, the combination can be achieved by combining active processing signals using passive circuitry, such as by using two resistors or by using an amplifier (such as an inverting amplifier with two input resistors and a feedback resistor).

[0056] Alternatively, signal combination can occur in the interconnection between the outputs of two active circuits. For example, if the active circuit of each coil has an amplifier or voltage-to-current converter with output impedance, connecting the outputs of the active circuits together should produce a sum of two active processed signals.

[0057] According to this disclosure, active processing signals from two or more coils (in the analog or digital domain) can be combined. The individual coils need not be identical, and they can have any suitable shape, such as partially circular (e.g., arc-shaped), linear, or any other shape. When active processing signals from the coils are combined, the resulting virtual combined coil covers or surrounds a larger portion of the current-carrying conductor than each individual coil covers or surrounds.

[0058] The location where the combination occurs can be shared by measurements for multiple conductors. For example, there can be a processor that receives signal streams from multiple coils of each conductor in a three-phase system.

[0059] The signal output from each coil represents the di / dt of the current in the current-carrying conductor. To determine the measured value of the current, the signal can be integrated before or after combination. Alternatively, other additional processing can be performed in the active circuit before signal combination, or in other circuits after signal combination, such as high-pass filtering, low-pass filtering, delay, offset compensation, or gain compensation.

[0060] Due to the design in this disclosure, measurement accuracy can be improved not only by allowing weighting and correction to be applied separately to each measuring coil that contributes to the final current measurement, but also by significantly improving sensitivity to electromagnetic noise pickup in the interconnections between measuring coils. Therefore, the effects of defects / asymmetries in the effectively combined coils can be reduced, and the integrity of the sensor signal output from the measuring coils can be improved by practically eliminating electromagnetic noise pickup that typically occurs in the electrical connections between coils. This should further improve the accuracy of current measurement. Furthermore, by reducing or minimizing discontinuities in the coils, the sensor's tolerance to changes in position and / or angle as a current-carrying conductor passes through can be enhanced, as the reduction in discontinuities should keep the sensor gain more consistent. Moreover, reducing the requirements for electrical connections between coils can reduce the complexity and cost of manufacturing and installation.

[0061] Figure 1 This is a schematic diagram of a known Rogowski coil, an example of a rate of change of magnetic field current sensor (sometimes called a dI / dt current sensor). To measure the current I(t) flowing through the current-carrying conductor 100, a measuring coil 102 is arranged such that the current-carrying conductor 100 passes through the measuring coil. The measuring coil 102 is wound in a helical shape such that one turn or loop of the helix encloses a cross-sectional area 104, Å. The current-carrying conductor 100 can be, for example, a busbar.

[0062] When the current I(t) in the current-carrying conductor 100 changes, the magnetic field generated by the current also changes. The positioning of the measuring coil induces a voltage in the measuring coil 102 that is proportional to the rate of change of current dI / dt. Therefore, integrating the output v(t) of the measuring coil yields a value proportional to the current. Each turn or loop of the coil forms a measuring area 104 in a plane perpendicular to the extension direction of the current-carrying conductor.

[0063] Figure 2A and Figure 2BA first example of a PCB-implemented clamp-on current sensor 200 is shown. The current sensor 200 includes a first PCB 210 on which a first measuring coil 220 is formed (e.g., using conductive traces on two layers of the first PCB 210—such as conductive traces on the upper and lower surfaces of the PCB 210—and conductive vias passing through the first PCB 210 and located between the upper and lower surfaces, as will be well understood by those skilled in the art). The current sensor 200 also includes a second PCB 230 on which a second measuring coil 240 is formed (e.g., using conductive traces on two layers of the second PCB 230—such as conductive traces on the upper and lower surfaces of the second PCB 230—and conductive vias passing through the second PCB 230 and located between the upper and lower surfaces, as will be well understood by those skilled in the art). If available, more PCB layers may be used to form the coil, or the layers for the coil may be internal to other layers of the PCB (e.g., sandwiched between other layers).

[0064] Figure 2A The current sensor 200 is shown from a direction perpendicular to or orthogonal to the surfaces of the first PCB 210 and the second PCB 230 (e.g., top view). Figure 2B The current sensor 200 is shown from a direction parallel to the surfaces of the first PCB 210 and the second PCB 230 (e.g., side view).

[0065] Figure 2A and Figure 2B A current sensor 200 in its in-place position is shown, surrounding a current-carrying conductor 250, such as a wire or busbar. A first PCB 210 and a second PCB 230 can be configured to be positioned relative to each other and the current-carrying conductor 250 to surround the conductor, and then clamped in that position (e.g., using clamping mechanisms on the first PCB 210 and the second PCB 230 that engage with each other to hold the first PCB 210 and the second PCB 230 in place). Figure 2A and Figure 2B The relative positions shown, or the use of some external clamping mechanism, such as a frame or housing.

[0066] exist Figure 2B In the example, the first PCB 210 and the second PCB 230 are configured to be positioned relative to each other such that the planes of the two PCBs are substantially aligned.

[0067] Figure 2C Alternative arrangements of the first PCB 210 and the second PCB 220 are shown. Figure 2CThe current sensor 200 is shown (e.g., side view) from a direction parallel to the surfaces of the first PCB 210 and the second PCB 230. This arrangement is consistent with... Figure 2B The arrangements are very similar, except that the first PCB 210 and the second PCB 220 are configured to be positioned relative to each other to surround the current-carrying conductor 250 and partially overlap each other when viewed from above.

[0068] exist Figures 2A to 2C In the example, the first measuring coil 220 and the second measuring coil 240 are configured to be passively electrically connected to each other to form a single combined coil. For example, each measuring coil will have two ends—one at the beginning of the coil and one at the end. The first end of each coil can be passively electrically connected to the first end of the other coil, for example, through a wire or lead. In a specific example, they can be connected to each other using a "spring pin". In this way, the two measuring coils can be electrically formed to form a single coil, such as a single Rogowski coil, that surrounds or encloses the current-carrying conductor 250.

[0069] Figure 2D An exemplary schematic circuit diagram illustrating the connection of a first measuring coil 220 and a second measuring coil 240 together is shown. A first end 222 of the first measuring coil 220 is connected to a first end 242 of the second measuring coil 240 via a conductor (such as a spring pin or wire). Second ends 224 of the first measuring coil 220 and second ends 244 of the second measuring coil 240 can be connected to a current measuring circuit 270. The current measuring circuit 270 is a circuit configured to determine a measured value of the current in the current-carrying conductor 250 based on an analog signal from the first measuring coil 220 (e.g., a signal at the second end 224 of the first measuring coil 220) and an analog signal from the second measuring coil 240 (e.g., a signal at the second end 244 of the second measuring coil 240). In one example, the two analog signals can be combined to form a differential signal, while in another example, the second end of one measuring coil can be grounded or held at a reference voltage, while other analog signals received from the other measuring coil can effectively be single-ended signals. Various components and devices that can form part of the current measuring circuit 270 will be readily understood by those skilled in the art and are therefore not described further herein.

[0070] The inventors have recognized that connecting the first measuring coil 220 and the second measuring coil 240 as described above has many disadvantages. In many cases, such as when using spring-loaded pins, the passive connection between the two coils needs to be aligned very precisely at a specific location. For example, the two sides of the spring-loaded pins need to be precisely positioned on the first PCB 210 and the second PCB 230 so that the first coil 220 and the second coil 240 are in the correct relative position when they are closed. If they are misaligned, this will create an imbalance in the signals output by the two coils, thus affecting the accuracy of the current measurement. Furthermore, the turn pitch of the coils constituting the first measuring coil 220 and the second measuring coil 240 is typically denser than that of the conductive connector 260. For example, the minimum dimensions of PCBs 210 and 230 are typically used to achieve the highest possible density of the first coil 220 and the second coil 240 (e.g., to make the turn pitch between each coil constituting the first coil 220 and the second coil 240 as small as possible). However, the conductive connector 260 typically does not match this turn pitch. As a result, the conductive connector 260 may introduce a certain degree of asymmetry, non-ideal characteristics, and / or irregularities into the coil formed by the first measuring coil 220 and the second measuring coil 240. This may again affect the accuracy of the current measurement.

[0071] In particular, spring-loaded connectors, the most common type of connection, typically increase the height of the coil (e.g., along the z-direction, i.e., perpendicular to the surface plane of the PCB) and / or cause displacement of the coil along the x- and / or y-directions. Other connectors with male and female components can be used, but these tend to increase height and cause inconsistencies between the coil and the desired coil configuration. This increases the overall asymmetry of the coil structure and can also expose the coil to interference (e.g., electromagnetic interference), thus reducing the accuracy of current measurements in the presence of external, unrelated magnetic fields (such as those generated by current in adjacent conductors). Furthermore, spring-loaded connectors (and other types of interconnects) tend to increase the overall complexity of device manufacturing and assembly. Additionally, their positional accuracy can be difficult to control and unpredictable, and their reliability can be poor.

[0072] Furthermore, the connection between the second terminals 224 and 244 of the first and second measuring coils 220 and 240 and the current measuring circuit 270 may be susceptible to interference. For example, due to size (or other) constraints, the current measuring circuit 270 may need to be located relatively far from the first and second measuring coils 220 and 240, possibly on a third PCB (not shown in the figures). This means that relatively long electrical connections are required to connect the second terminals 224 and 244 to the current measuring circuit 270. Such electrical connections are prone to picking up signal noise, such as noise from electromagnetic (EM) interference. Since the signals from the first and second measuring coils 220 and 240 are typically very small (e.g., less than 1 mV rms for a 100 A RMS signal at 50 Hz), this interference can significantly reduce the signal-to-noise ratio (SNR), even if the size of the additional loop associated with the electrical interconnect is only a few millimeters. Even if the current measurement circuit 270 can be positioned on one of the first PCB 210 or the second PCB 230, relatively close to the second end of the first measurement coil 220 or the second measurement coil 240, it is still necessary to establish a connection between the second end of the other measurement coil and the current measurement circuit 270, which may easily pick up signal noise.

[0073] Figure 3 An exemplary schematic diagram of a system 300 according to one aspect of this disclosure is shown, which the inventors developed to address the aforementioned drawbacks. The system includes a first PCB 310 on which a first measuring coil 320 is formed, and a second PCB 340 on which a second measuring coil 350 is formed. (See reference...) Figures 2A to 2D As in the described example, the first measuring coil 320 and the second measuring coil 350 are configured to be positioned relative to each other and the current-carrying conductor 380 to at least partially surround (or enclose) the current-carrying conductor. System 300 can be configured such that when in place around conductor 380, the first PCB 310 and the second PCB 340 are substantially aligned, similar to... Figure 2B Or, such that when viewed from above, the first PCB 310 and the second PCB 340 partially overlap each other, similar to Figure 2C .

[0074] System 300 also includes a first electronic circuit 330, which includes a first input coupled to a first measuring coil 320 and a first output coupled to a measuring circuit 370 (in this example via a combination circuit 390, as explained below). For example, a first end of the first measuring coil 320 may be coupled to the first electronic circuit 330, and a second end of the first measuring coil 320 may be coupled to a reference voltage, such as ground. In this case, the first electronic circuit 330 receives a first sensor signal from the first measuring coil 320 as a single-ended signal. Alternatively, both the first and second ends of the first measuring coil 320 may be coupled to the first electronic circuit 330, for example, where the first measuring coil 320 includes a plurality of coils or turns and a return wire passing through the center of the coil from one end to the other, such that the first and second ends of the first measuring coil 320 terminate close to each other (e.g., this is a well-known characteristic of Rogowski coils). In this case, the first electronic circuit 330 receives a first sensor signal from the first measuring coil 320 as a differential signal. Therefore, it can be seen that the first electronic circuit 330 can be positioned very close to the end of the first measuring coil 320 to which it is coupled. This should minimize any signal interference that may be picked up by the conductor that couples the end of the first measuring coil 320 to the first electronic circuit 330. As a result, even if the signal received by the first electronic circuit 330 may be relatively small (e.g., less than 1 mVrms for a 100 A RMS signal at 50 Hz), it should still have a good signal-to-noise ratio because the noise pickup caused by its interference should be very small or zero.

[0075] System 300 also includes a second electronic circuit 360, which includes a second input coupled to the second measuring coil 350 and a second output for coupling to the measuring circuit 370 (in this example via a combination circuit 390, as explained below). For example, a first end of the second measuring coil 350 may be coupled to the second electronic circuit 360, and a second end of the second measuring coil 350 may be coupled to a reference voltage, such as ground. In this case, the second electronic circuit 360 receives a second sensor signal from the second measuring coil 350 as a single-ended signal. Alternatively, both the first and second ends of the second measuring coil 350 may be coupled to the second electronic circuit 360, for example, where the second measuring coil 350 includes a plurality of coils or turns and a return wire passing through the center of the coil from one end to the other, such that the first and second ends of the second measuring coil 350 terminate close to each other (e.g., this is a well-known characteristic of Rogowski coils). In this case, the second electronic circuit 360 receives a second sensor signal from the second measuring coil 350 as a differential signal. Therefore, it can be seen that the second electronic circuit 360 can be positioned very close to the end of the second measuring coil 350 to which it is coupled. This should minimize any signal interference that may be picked up by the conductor that couples the end of the second measuring coil 350 to the second electronic circuit 360. As a result, even if the signal received by the second electronic circuit 360 may be relatively small (e.g., less than 1 mVrms for a 100 A RMS signal at 50 Hz), it should still have a good signal-to-noise ratio because the noise pickup caused by its interference should be very small or zero.

[0076] The first electronic circuit 330 and the second electronic circuit 360 may each include one or more of the following circuits / devices: one or more amplifiers; analog-to-digital converters (ADCs); voltage-to-current (V-2-I) converters. The first electronic circuit 330 and the second electronic circuit 360 may be referred to as “active” circuits because they include one or more powered devices / circuits, rather than circuits consisting only of passive components / devices such as wires / traces, resistors, and capacitors.

[0077] In one example, the first electronic circuit 330 and the second electronic circuit 360 may each include one or more amplifiers configured to generate amplified versions of the first sensor signal received from the first measuring coil 320 and the second sensor signal received from the second measuring coil 350. Any suitable type of amplifier circuit can be used. In this case, the first electronic circuit 330 generates and outputs a first active processed signal as an amplified version of the first sensor signal, and the second electronic circuit 360 generates and outputs a second active processed signal as an amplified version of the second sensor signal. The combination circuit 390 and / or the current measurement circuit 370 may be located close to one of the first electronic circuit 330 or the second electronic circuit 360 (e.g., mounted on the first PCB 310 or the second PCB 340), or they may be located at a relatively distant location, such as on a third PCB. In any case, noise is likely to be picked up in the electrical connections between the first electronic circuit 330 and the combination circuit 390 and / or the current measurement circuit 370, and in the electrical connections between the second electronic circuit 360 and the combination circuit 390 and / or the current measurement circuit 370. However, since the active processing signals transmitted from the first electronic circuit 330 and the second electronic circuit 360 are amplified versions of the first sensor signal and the second sensor signal, as described above... Figure 2A and Figure 2D Compared to the given example, this should improve the integrity and signal-to-noise ratio of the signal received at measurement circuit 370. This is because the signal is at an amplified level for the same additional loop of interconnects, and therefore the pickup level is reduced relative to the amplified signal level. Therefore, better integrity and signal-to-noise ratio should be achieved regardless of where the combination circuit 390 and / or the current measurement circuit 370 are located, and regardless of the conductive wiring between the different circuits, which should improve the accuracy of the measurements performed by measurement circuit 370. Combination circuit 390 and current measurement circuit 370 can be implemented separately, for example in separate packages or ICs that can be mounted on the same or different PCBs, or they can be implemented together, for example in the same package or IC. Alternatively, the circuits can be combined in the same IC, for example, one coil locally coupled to a first IC including active processing circuitry (e.g., an amplifier) ​​and combination circuit 390, and another coil locally coupled to a second IC including only active processing circuitry (e.g., an amplifier), and then the second IC sends its signal to the first IC via interconnects.

[0078] In another example, the first electronic circuit 330 may include a first ADC to generate a first digital conversion of the first sensor signal, and the second electronic circuit 360 may include a second ADC to generate a second digital conversion of the second sensor signal. Alternatively, the first electronic circuit 330 and the second electronic circuit 360 may each include amplifiers configured to amplify the first sensor signal and the second sensor signal, respectively, wherein the first ADC and the second ADC are configured to convert amplified versions of the first sensor signal and the second sensor signal, respectively. In either case, the first ADC and the second ADC are configured to generate and output a first digital signal and a second digital signal that depend on the first sensor signal and the second sensor signal. Any suitable type of ADC can be used, such as SAR, flash, sigma-delta, etc.

[0079] By communicating the first and second active processed signals as digital signals, the signals should be substantially or completely immune to electromagnetic noise pickup (e.g., as long as the level of electromagnetic interference is not high enough to disrupt the logic levels used to transmit the digital signals). Therefore, a good signal-to-noise ratio should be maintained regardless of where the combination circuit 390 and / or the measurement circuit 370 are located, and regardless of the conductive wiring between the circuits.

[0080] In another example, the first electronic circuit 330 may include a first voltage-to-current converter to generate a first current dependent on the voltage of the first sensor signal, and the second electronic circuit 360 may include a second voltage-to-current converter to generate a second current dependent on the voltage of the second sensor signal. Optionally, the first electronic circuit 330 and the second electronic circuit 360 may include amplifiers to amplify the first and second sensor signals before they are converted by the first and second voltage-to-current converters. Current signals are more resistant to magnetic noise pickup than voltage signals because the electromagnetic effect on the additional interconnect loops generates a voltage that only slightly alters the current due to the output impedance of the current source of the voltage-to-current converter. Therefore, converting the signal to this form before it is output from the first electronic circuit 330 and the second electronic circuit 360 should improve electromagnetic noise immunity. Thus, a good signal-to-noise ratio should be maintained regardless of where the combined circuit 390 and / or the current measurement circuit 370 are located, and regardless of the conductive wiring between the circuits.

[0081] In all these examples, the term "actively processed signal" refers to a signal generated by acting on a sensor signal output from a measuring coil through some form of active electronic circuitry (including, but not limited to, amplification and / or digital conversion and / or voltage-to-current conversion). It should be noted that more than one type of active processing can occur; for example, amplification can occur before an ADC or voltage-to-current converter. Furthermore, the electronic circuitry can optionally perform one or more additional signal processing functions, whether passive or active, such as signal filtering (high-pass and / or low-pass), integration, signal delay, signal offset, gain compensation, etc.

[0082] If the combined signal is an analog signal, the measurement circuit 370 can measure the electrical measurand in the analog domain, or it can digitally convert the combined signal and measure the electrical measurand in the digital domain.

[0083] In summary, it can be seen that in all examples of the first electronic circuit 330 and the second electronic circuit 360, significantly greater positioning flexibility of the measurement circuit 370 is achieved while improving (or at least not sacrificing) the signal-to-noise ratio of the signal received at the measurement circuit 370. Furthermore, the electrical coupling between the first measurement coil 320 and the second measurement coil 350 is eliminated; instead, the coil-based output signals are combined elsewhere by the combination circuit 390. This further reduces signal interference, improves coil symmetry and regularity, and means that components such as spring pins are unnecessary. Therefore, improved positioning flexibility of the current measurement circuit 370 can be achieved, which simplifies the manufacture and / or installation of the system 300 while maintaining or improving the accuracy of current measurement due to the good signal-to-noise ratio and good measurement coil symmetry. Moreover, by reducing or minimizing discontinuities in the coil, the sensor's tolerance to changes in position and / or angle as the current-carrying conductor passes through can be enhanced, as the reduction in discontinuities should keep the sensor gain more consistent.

[0084] Figure 4A schematic diagram of an alternative implementation of system 300 is shown, in which the first electronic circuit 330 and the second electronic circuit 360 are positioned differently relative to the first measuring coil 320 and the second measuring coil 350. The first electronic circuit 330 and the second electronic circuit 360 can be positioned anywhere on the first PCB 310 and the second PCB 340, typically depending on the specific design of the first measuring coil 320 and the second measuring coil 350, for example, to be close to the end (or tip) of the measuring coil to which the electronic circuit is coupled. In this example, coils 320 and 350 can be differential in nature, with a balanced positive coil extending counterclockwise from the electronic circuit and a negative coil extending clockwise from the electronic circuit to produce differential pickup. A potential advantage of this arrangement is that the electronic circuits can be positioned away from each board edge, thus allowing the boards to be adjacent more closely and symmetrically to form dummy coils.

[0085] Figure 5 A schematic circuit diagram of system 300 is shown. In this example, both ends of the first measuring coil 320 are coupled to the first electronic circuit 330, and both ends of the second measuring coil 350 are coupled to the second electronic circuit 360. The measuring coils can be made of multiple parts (e.g., using return wires, as is well known in Rogowski coils). A bias voltage or ground connection can be present in the middle of each coil, such that the signals received at the first electronic circuit 330 and the second electronic circuit 360 are differential with respect to the bias voltage or ground. As a result, the first electronic circuit 330 and the second electronic circuit 360 receive a first sensor signal and a second sensor signal as differential signals. Alternatively, system 300 can be configured such that the first sensor signal and the second sensor signal are single-ended, as previously described. Furthermore, although the outputs of the first and second electronic circuits are shown as single-ended, they can be differential. Similarly, although the output of the combination circuit 390 is shown as single-ended, it can be differential.

[0086] The combination circuit 390 is arranged to combine the first active processing signal and the second active processing signal to generate a combined signal and output the combined signal to the measurement circuit 370, thereby coupling the output of the first electronic circuit 330 to the measurement circuit 370 and coupling the output of the second electronic circuit 360 to the measurement circuit 370. The combined signal may, for example, be the sum or average of the first and second active processing signals, and the combination circuit 390 may include any suitable passive and / or active circuitry configured for this purpose.

[0087] Figure 6An exemplary embodiment of the combinational circuit 390 is shown, which includes an inverting amplifier formed by operational amplifier A and resistors R1, R2, and Rf. As a result, the combined signal output by the combinational circuit 390 is a weighted average of an analog first active processed signal and an analog second active processed signal, wherein the weighting is determined by the relative magnitudes of R1 and R2. It should be understood that any other suitable amplifier circuit can be used, such as an inverting or non-inverting amplifier, or one or more transistors appropriately biased through resistors, etc. In this example, the combinational circuit 390 is an active circuit.

[0088] In this example, Vcm is the common-mode voltage of the first coil 320 and the second coil 350, for example, where one end of each coil (such as the return lead end) is coupled to a reference voltage or ground, such that the analog signals output by the first coil 320 and the second coil 350 are differential with respect to Vcm. In this example, the gain applied to the first active processed signal is determined by the relative magnitudes of R1 and Rf, and the gain applied to the second active processed signal is determined by the relative magnitudes of R2 and Rf. The amplifier output is a weighted average of the two active processed signals, where the weighting is determined by the relative gain applied to each signal.

[0089] Figure 7 Another exemplary embodiment of the combinational circuit 390 is shown, which includes two resistors R3 and R4 formed as a voltage divider. If R3 and R4 are matched (i.e., have the same resistance value), the combined signal is the average of an analog first active processing signal and an analog second active processing signal. Alternatively, R3 and R4 may not be matched, but may have different resistance values, such that the combined signal is effectively a weighted average of the first and second active processing signals. This can be used, for example, to correct an inherent imbalance in the relative design of the first coil 320 and the second coil 350 (e.g., one coil is larger than the other), or to correct an imbalance caused by defects in the manufactured coils 320, 350 and / or electronic circuits 330, 360. For this purpose, one or both resistors may be variable, allowing the weighting to be adjusted during system calibration. In this example, the combinational circuit 390 is a passive circuit.

[0090] In an alternative, if the first electronic circuit 330 and the second electronic circuit 360 have high output impedance (e.g., if they have voltage-to-current converters or high output impedance amplifiers), the combination circuit 390 can simply connect the outputs of the first electronic circuit 330 and the second electronic circuit 360 together to generate a combined signal that is the sum of the first active processing signal and the second active processing signal.

[0091] In another alternative, if both the first and second active processed signals are analog, the combinational circuit 390 may include one or more analog-to-digital converters (ADCs) (e.g., an ADC shared between the first and second active processed signals using a multiplexer, or an ADC for each of the first and second active processed signals) and digital circuitry to combine the two digital signals, for example, by averaging or summing them. Alternatively, if the first and second active processed signals received by the combinational circuit 390 are digital signals, the combinational circuit 390 may include only digital circuitry to combine the two digital signals, for example, by averaging or summing them. In both cases, the combined signals are digital signals, and the combinational circuit 390 is an active circuit.

[0092] The measuring circuit 370 can be configured to measure any one or more electrical quantities that depend on the current in the current-carrying conductor 380. For example, it can be configured to measure any one or more of the following:

[0093] • Use the received combined signal to measure the rate of change of current in current-carrying conductor 380;

[0094] • The amplitude (and optionally polarity) of the current in the current-carrying conductor 380 is measured by integrating the received combined signal.

[0095] • Electrical energy associated with the current in the current-carrying conductor 380, for example by determining the magnitude of the current in the current-carrying conductor 380 and multiplying it by a voltage measurement;

[0096] • Electrical power associated with the current in the current-carrying conductor 380, for example by determining the energy per unit time.

[0097] Therefore, it can be seen that the system 300 of this disclosure can be used as part of an energy meter configured to measure energy consumption for billing purposes.

[0098] Figure 8An exemplary embodiment of an electricity meter 800 is shown. The current-carrying conductor 380 is not part of the electricity meter 800, but rather a conductor carrying the current measured by the electricity meter 800. For example, it could be a live wire supplying power to a residential or industrial building. The measuring circuit 370 is also configured to receive a voltage signal 810 indicating a voltage associated with the current in conductor 380, such that the energy and / or power supplied by the current in conductor 380 can be measured by the measuring circuit 370. In this example, the electricity meter 800 measures the current in only one conductor, but it should be understood that it can be configured to measure the current in more than one conductor, such as in the live and neutral wires supplying power to a residential or industrial building, or in each phase conductor of a multiphase power supply (in which case the signals for each phase can be combined at the same location to generate a combined signal for each phase, or the combined signal for each phase can be generated by separate combining circuits located at different locations). In such examples, a first measuring coil and a second measuring coil can be mounted to each conductor to be measured, and each pair of measuring coils can have an associated combining circuit 390. In this way, the measuring circuit 370 can receive combined signals from each pair of measuring coils, thereby enabling the measurement of the current in each conductor.

[0099] Additional or alternative uses for measuring electrical quantities include, for example, one or more of motor control, condition-based monitoring, fault detection, etc. Therefore, the measurement circuit 370 can be part of a wider system, or other systems can use the measured values ​​output by the measurement circuit 370.

[0100] Those skilled in the art will readily understand that various changes or modifications can be made to various aspects of this disclosure without departing from its scope.

[0101] Figure 9 An exemplary schematic diagram of a system 900 according to an alternative implementation is shown. This example is related to... Figure 3 and Figure 4Those examples are very similar, but do not include a dedicated second electronic circuit 360. Instead, a second measuring coil 350 is coupled to the measuring circuit 970, ideally as close as possible to the coil end of the second measuring coil 350. In this example, the measuring circuit 970 is mounted on a second PCB 340 and effectively includes the second electronic circuit 360, the combination circuit 390, and the measuring circuit 370. It includes circuitry equivalent to the second electronic circuit 360, such that the first sensor signal and the second sensor signal can be processed in an equivalent manner (e.g., converted to digital or current signals) before being combined. As mentioned above, the electrical coupling from the first electronic circuit 330 to the measuring circuit 970 should be largely or completely immune to noise pickup, and by positioning the measuring circuit 970 close to the second measuring coil 350, the signal-to-noise ratio of the second sensor signal should also be good. Furthermore, as explained above, no electrical coupling is required between the first measuring coil 320 and the second measuring coil 350. This further reduces signal interference, improves coil symmetry and regularity, and means that components such as spring pins are unnecessary. Therefore, the measurement accuracy of the electrical measured object should be improved due to the good signal-to-noise ratio and good measuring coil symmetry, while reducing complexity and cost by eliminating the need for an electrical connection between the first measuring coil 320 and the second measuring coil 350. Moreover, by reducing or minimizing discontinuities in the coils, the sensor's tolerance to changes in position and / or angle as a current-carrying conductor passes through can be enhanced, as the reduction in discontinuities should keep the sensor gain more consistent.

[0102] In each of the examples above, the signals from each measuring coil 320 and 350 are combined. As a result, the combined signal effectively represents the signal from a dummy coil corresponding to the combination of the two measuring coils 320 and 350, whereas in reality, the two electrically separated measuring coils each partially wrap around the current-carrying conductor 380. As previously stated, therefore, an electrical connection between the two measuring coils 320 and 350 is unnecessary, which reduces manufacturing and installation costs and complexity, and improves the accuracy of current measurement.

[0103] Furthermore, allowing different weights to be applied to the measurement signals corresponding to each measurement coil can have many benefits. In one example, it can be used to correct for defects in the first measurement coil 320 and the second measurement coil 350. For instance, the manufacturing thickness of the first PCB 310 and the second PCB 340 may differ slightly, which would mean that the coil dimensions of the first measurement coil 320 and the second measurement coil 350 would be different, resulting in different levels of induced signals in the coils. This can be detected during device calibration and can be corrected by changing the relative weights of the two signals combined by the current measurement circuits 370, 970 to measure the current (e.g., changing it to 49:51, or 52:48, etc.). The relative weighting can be adjusted in any one or more of the following ways: adjusting the relative amplifier gain of the first electronic circuit 330 and the second electronic circuit 360; adjusting the digital conversion performed by the first electronic circuit 330 and the second electronic circuit 360 (e.g., by changing the converter reference value or applying a multiplication operation after conversion); and / or by adjusting the voltage-to-current conversion performed by the first electronic circuit 330 and the second electronic circuit 360 (e.g., by changing the current reference value) and / or adjusting the relative weighting of the active processed signal digitally or analogally at the combination circuit 390 before combination.

[0104] A further benefit of the flexibility provided by this method of electrically combining signals is that the dimensions of the first measuring coil 320 and the second measuring coil 350 can be intentionally designed to be different. The first measuring coil 320 is designed to cover or surround a first perimeter, or circumferential portion (or a first arc), of the current-carrying conductor 380, and the second measuring coil 350 is designed to cover or surround a second perimeter, or circumferential portion (or a second arc), of the current-carrying conductor 380. In the example above, the first perimeter portion and the second perimeter portion have equal dimensions (e.g., each covering a 180-degree angle). However, in an alternative, the first circumferential portion and the second circumferential portion can have different dimensions.

[0105] Figure 10An exemplary schematic diagram of a system 1000 according to one aspect of this disclosure is shown, wherein a first perimeter portion and a second perimeter portion have different dimensions. In this example, a first measuring coil 320 and a second measuring coil 350 each partially surround a current-carrying conductor 380. However, the first measuring coil 320 partially surrounds more of the current-carrying conductor 380 than the second measuring coil 350. In other words, the first perimeter, or circumferential portion (or first arc) of the current-carrying conductor 380 adjacent to the first measuring coil 320 is larger than the second perimeter, or circumferential portion (or second arc) of the current-carrying conductor 380 partially surrounded by the second measuring coil 350. In other words, the angle covered by the first measuring coil 320 is larger than the angle covered by the second measuring coil 350. The sensor signals output from the first measuring coil 320 and the second measuring coil 350 can then be appropriately weighted (e.g., 75:25) by the first electronic circuit 330, the second electronic circuit 360, and / or the combined circuit 390. This allows for greater flexibility in the design of the measuring coil, such as enabling the creation of designs suitable for specific spaces, allowing the measuring coil to be mounted around current-carrying conductors 370 that were previously unable to be mounted due to physical space limitations.

[0106] For example, in each of the above examples, the current measurement system is configured such that when the first measuring coil 320 and the second measuring coil 350 are in place relative to the current-carrying conductor 380, they together completely surround or enclose the current-carrying conductor 380 (i.e., around the current-carrying conductor 360 degrees). In non-overlapping PCBs (such as...) Figure 2B In the case shown), the two measuring coils can cover 360 degrees together. In overlapping PCBs (such as...) Figure 2C In the case shown, the two measuring coils can together cover more than 360 degrees. However, in an alternative, they can together only partially wrap around the current-carrying conductor by 380 degrees, for example, covering less than 360 degrees together. For example, they could together cover 300 degrees, or 350 degrees, etc.

[0107] Figure 11 An example system 1100 according to one aspect of this disclosure is shown, wherein two measuring coils are each configured to partially wrap around conductor 380, and together partially but not completely wrap around conductor 380. Furthermore, in this example, each coil is not a loop shape, but is oriented linearly. System 1100 includes a first coil 1120 formed on a first PCB 1110 and a second coil 1150 formed on a second PCB 1140.

[0108] In each of the above examples, the first and second measuring coils are configured such that they each cover or partially surround a corresponding perimeter portion of the current-carrying conductor, and together cover a combined perimeter portion of the current-carrying conductor 380 that is larger than the portion covered by each measuring coil itself. This is true regardless of whether the perimeter portions covered by each measuring coil are the same or different, and regardless of whether the combined perimeter portion completely or only partially surrounds the current-carrying conductor 380.

[0109] Additionally or alternatively, the current measurement system may include more than two measurement coils. For example, it may include three or more measurement coils, each implemented on a corresponding PCB and configured to be positioned relative to each other and the current-carrying conductor 380 to at least partially surround the current-carrying conductor 380. In this case, each measurement coil may have the corresponding electronic circuitry as described above.

[0110] In each example given above, there is a single current sensor coil consisting of two or more separate measuring coils 320 and 350. Alternatively, the current measurement system may include two or more current sensor coils, each consisting of two or more separate measuring coils 320 and 350, implemented on a corresponding PCB. Each measuring coil may have corresponding electronic circuitry (or all but one measuring coil may have corresponding electronic circuitry), and as described above, measuring circuits 370, 570 may use the outputs of these electronic circuits to determine the measured value. Such an example could be one current measuring coil extending with clockwise spiral turns around the current-carrying conductor 380, and another current measuring coil extending with counterclockwise spiral turns around the current-carrying conductor 380.

[0111] For example, Figure 12An embodiment of system 1200 according to one aspect of this disclosure is shown. In this example, four measuring coils are arranged around a current-carrying conductor 380—a first measuring coil on a first PCB 310, a second measuring coil on a second PCB 340, a third measuring coil on a third PCB 1240 (which is essentially a copy of the second measuring coil, but with the coil turns wound in the opposite direction), and a fourth measuring coil on a fourth PCB 1210 (which is essentially a copy of the first measuring coil, but with the coil turns wound in the opposite direction). A third electronic circuit 1260 is essentially a copy of the second electronic circuit 360, and a fourth electronic circuit 1230 is essentially a copy of the first electronic circuit 330. A combination circuit 390 combines the active processing signals from all four electronic circuits to generate a combined signal, or combines the first and second active processing signals to generate a first combined signal, and combines the third and fourth active processing signals (output by the third electronic circuit 1260 and the fourth electronic circuit 1230) to generate a second combined signal. In the latter case, the first combined signal and the second combined signal can then be used by the measurement circuit 370 to measure the electrical measured quantity.

[0112] In each of the examples given above, the measuring coil is implemented on a PCB. However, the principles of this disclosure can be applied to current measuring coils implemented in any other manner.

[0113] Furthermore, in most of the examples described above, the combination circuit 390 and the measurement circuit 370 are separate circuits. However, they can be implemented within the same package or IC, in which case they can be considered as a single circuit. Additionally, in some cases, the function of combining the first active processing signal and the second active processing signal can be performed by the measurement circuit 370, for example, when the first and second active processing signals are digital signals and the measurement circuit 370 combines them as part of its measurement function.

[0114] In the example above, the measuring coils are located within the PCB substrate. Alternatively, they can be formed on or within other types of substrates, or using other types of windings. For example, the windings can be formed in a flexible manner, or implemented using different substrate materials, or made by winding wires around a mechanical structure.

[0115] Implementation of wire-wound conductor

[0116] The preceding disclosures utilized split-type or clamp-on rate-of-change current sensors. As mentioned above, using active processing on each different part of the current sensor can improve the signal-to-noise ratio.

[0117] A typical current sensor can use a conductor to carry current, which passes through an opening or hole in one or more substrates. A measuring coil on the substrate can be positioned such that a voltage proportional to the rate of change of current in the conductor is induced in the measuring coil.

[0118] To increase the system's sensitivity, the conductor can be arranged to pass through the opening or hole two or more times, for example, by winding it around the substrate. However, this can be difficult to manufacture because the conductor must pass through the opening in the substrate multiple times. In practice, with limited conductor flexibility, it may be impossible to pass it through the opening. Furthermore, winding may be difficult to automate, or it may be time-consuming for a person to wind the conductor.

[0119] The inventors have recognized that, for split-type coil current sensors, such as those described above, a conductor can be wrapped or wound around one portion / substrate of the split-type coil current sensor before the second portion / substrate is brought into place relative to the first portion / substrate. When both portions / substrates are subsequently brought into place, the first coil and the second coil formed on the first portion / substrate and the second portion / substrate can substantially surround the wound conductor, such that the same conductor passes through the opening formed by the first portion and the second portion multiple times or between the first portion and the second portion, for example, two, three, four times, etc. In other words, at least two portions or points of the conductor are substantially surrounded or enclosed, while the remaining portions or points of the conductor are used to wrap around the outside of the substrate. Since the substrate / portion is brought into place only after the conductor is wound around the first portion / substrate, it is not necessary for the conductor to pass through the opening. Furthermore, the pre-wound conductor can be looped over the first portion / substrate. After the conductor is positioned above the first portion / substrate, the second portion / substrate can be brought into place such that the two coils substantially surround or enclose the wound conductor at at least two portions or points of the conductor. Using pre-wound conductors means that conductor winding can be performed very efficiently in the factory, and conductors that are very difficult or impossible to wind manually can be used with rigid and / or wire gauges.

[0120] Using wound conductors and split coil current sensors in this way can produce current sensors with increased sensitivity, enabling the measurement of low currents while simplifying sensor manufacturing and installation.

[0121] By using a wound conductor and active signal processing within the same current sensor system, the signal-to-noise ratio (SNR) of the system is significantly improved. Active coupling makes the system less susceptible to electromagnetic noise pickup (e.g., stray electromagnetic fields from adjacent unrelated conductors). This improves the SNR by reducing noise, thereby increasing the integrity of the signal received by the current measurement circuitry and thus improving the accuracy of the current measurement. This can be particularly effective when the first electronic circuitry is located close to the first measuring coil, minimizing electromagnetic noise pickup in the conductor between the measuring coil and the electronic circuitry. Using such active processing can improve the performance of a split coil to a degree that significantly expands its useful applications, including situations where split coils were previously not considered. For example, in cases requiring the measurement of relatively small currents (which are typically where a wound conductor might be used), the disadvantages of split coils would be too great to even consider their use. However, due to the significant performance improvement resulting from the active processing of the split coil, the inventors have recognized that by combining a wound conductor (which increases the amplitude of the measured signal) with a split active signal processing measuring coil, the overall system SNR can be further improved in a very direct manner.

[0122] Figure 13a A current sensor 1300 comprising a single substrate 1310 or PCB is shown. A first measuring coil 1320 is formed on the substrate 1310 (e.g., using conductive traces on two or more layers of the first substrate 1310—such as conductive traces on the upper and lower surfaces of the substrate 1310—and conductive vias through the substrate 1310 between the upper and lower surfaces, as will be well understood by those skilled in the art). A conductor 1330 suitable for carrying the current measured by the current sensor 1300 passes through the first measuring coil 1320. This conductor 1330 may be referred to as the measured conductor or primary conductor because the current sensor 1300 is used to measure the current flowing through the conductor 1330. The substrate 1310 may include an opening 1340 or other opening through which the conductor 1330 can pass. The positioning of the measuring coil 1320 relative to the conductor 1330 causes a voltage in the measuring coil 1320 to be proportional to the rate of change of the current flowing through the conductor 1330, dI / dt.

[0123] The sensitivity of the current sensor 1300 is limited by the number of turns or loops of the measuring coil 1320 and the cross-sectional area of ​​each turn or loop of the measuring coil 1320. However, both the number of turns and the cross-sectional area per turn are limited by manufacturing constraints. For example, the PCB or substrate on which the measuring coil 1320 is implemented may have many constraints, such as minimum distance between conductors, minimum via size requirements, minimum conductor trace width, etc. Therefore, increasing the sensitivity of the current sensor 1300 within the space-constrained area of ​​the PCB is difficult.

[0124] The signal induced in the measuring coil 1320 is proportional to the rate of change of the current flowing through the conductor 1330, dI / dt. Regardless of the magnitude of the current flowing through the conductor 1330, the noise coupled into the sensor can be essentially constant. The noise may be caused by external fields or interfering fields. Therefore, when the current flowing through the conductor 1330 is large, the signal-to-noise ratio (SNR) of the current sensor output may be high, while when the current flowing through the conductor 1330 is small, the SNR is low. Thus, large currents, such as those in the order of 100A, 200A, and 500A, can be easily measured by the current sensor 1300. However, relatively small currents, such as those in the order of 5A, 2A, 1A, and 500mA, may be more difficult to measure accurately because the SNR may be relatively low. This may reduce measurement accuracy or make it difficult or impossible to determine the current based on the output of the current measuring coil 1320. Therefore, a current sensor with improved sensitivity is needed.

[0125] Figure 13b A current sensor 1350 is shown. Many components of the current sensor 1350 are related to... Figure 13a The same reference numerals are used for the same parts as described herein. Three conductors 1330 pass through the measuring coil 1320. These conductors may represent a single conductor 1330 that has passed through the opening 1340 multiple times, such that current flows through the opening multiple times in the same direction. For example, conductor 1330 may be wound around the substrate 1310 multiple times. A voltage proportional to the current in all three conductors 1330 is induced in the measuring coil 1320.

[0126] In other words, if Figure 13a The same current flows through conductor 1330. Figure 13b Each of the three sections of the middle conductor 1330, then Figure 13b The signal induced in the current measuring coil 1320 can be Figure 13a Three times higher. By winding the same conductor multiple times through the opening 1340, the same current can essentially be measured multiple times. This improves the signal-to-noise ratio of the current sensor 1350 compared to the current sensor 1300. Furthermore, due to the larger signal amplitude of the given current in the measured conductor, the input equivalent noise of any subsequent amplification or analog-to-digital conversion is reduced.

[0127] Therefore, the sensitivity of the current sensor 1350 can depend on the number of times the conductor 1330 passes through the opening 1340. Thus, winding a single conductor around the substrate 1310, through the opening 1340, and around one side of the substrate 1310 can produce a current sensor with increased sensitivity. However, winding the conductor 1330 in this manner can lead to many manufacturing difficulties.

[0128] Figure 14a , Figure 14b, Figure 14c and Figure 14d The process of winding conductor 1330 around substrate 1310 and passing it through opening 1340 multiple times is shown in four stages.

[0129] Figure 14a The first stage of the process of winding conductor 1330 around substrate 1350 is shown. Conductor 1330 passes through or through opening 1340 and passes through substrate 1310 from one side to the other.

[0130] Figure 14b The second stage of the process of winding conductor 1330 around substrate 1350 is shown. Conductor 1330 is twisted, bent or deformed so that it passes through opening 1340 and then folded or twisted back on the other side of the substrate.

[0131] Figure 14c The third stage of the process of winding conductor 1330 around substrate 1310 is shown. In the third stage, conductor 1330 is further bent or twisted so that it passes through opening 1340 for the second time. Thus, conductor 1330 passes through opening 1340 twice, so that the current flowing through conductor 1330 will pass through opening 1340 twice in the same direction.

[0132] Figure 14d The fourth stage of the process of winding conductor 1330 around substrate 1310 is shown. Conductor 1330 is again twisted, bent, or deformed. As a result, conductor 1330 forms a coil, in which it passes through opening 1340 twice. As a result, two different portions or points of conductor 1330 are surrounded by coil 1320, such that coil 1320 measures the current twice when current flows through conductor 1330. As a result, this increases the sensitivity of current sensor 1350 by approximately two times.

[0133] However, as Figures 14a to 14d The process of winding the conductor through the opening, as shown, presents numerous manufacturing challenges. Specifically, the conductor 1330 must pass through the opening 1340 multiple times. Winding the conductor 1330 through the opening in this manner requires the conductor 1330 to be continuously released and picked up again on different sides of the substrate. This can significantly increase the manufacturing time of a robotic manufacturing system. It can be a time-consuming and inconvenient process, difficult to automate. Furthermore, where the conductor 1330 has limited flexibility, winding it through the opening may be impossible because the conductor may not be able to bend at an angle capable of passing through the opening 1340. This may limit the thickness, diameter, or wire gauge of the conductor 1330 that can be used, or the type of conductor 1330 that can be used.

[0134] Figure 15aA current sensor 1500 comprising multiple portions or substrates is shown. The current sensor includes a first substrate / portion 1510 on which a first measuring coil 1530 is formed. The current sensor includes a second substrate / portion 1520 on which a second measuring coil 1540 is formed. The measuring coils can be formed as described above in this disclosure, for example, using conductive traces on two layers of the substrate—such as conductive traces on the upper and lower surfaces of the substrate—and conductive vias through the substrate between the upper and lower surfaces, as will be well understood by those skilled in the art. When used as a current sensor, the first substrate 1510 and the second substrate 1520 are positioned relative to each other to substantially surround or enclose a conductor 1550. The conductor 1550 is positioned between the first substrate 1510 and the second substrate 1520, for example in an opening, aperture, or space 1560 formed between the first substrate 1510 and the second substrate 1520.

[0135] The first substrate 1510 can be of any suitable shape and includes a first slot, opening, or hole. The second substrate 1520 can be of any suitable shape and includes a second slot, opening, or hole. When the first substrate 1510 and the second substrate 1520 are positioned adjacent to or near each other, the first slot, opening, or hole of the first substrate 1510 and the second slot, opening, or hole of the second substrate 1520 can form an opening 1560. The opening 1560 is adapted for a conductor 1550 to pass from one side of the substrate to the other, such that the conductor is substantially surrounded by the first substrate 1510 and the second substrate 1520, and more specifically surrounded by the first measuring coil 1530 and the second measuring coil 1540.

[0136] Figure 15b and Figure 15c A first substrate 1510 and a second substrate 1520 are shown in different positions, such that they are separated from each other. The first substrate 1510 and the second substrate 1520 can be separate components and can be manufactured separately. The fact that the first substrate 1510 and the second substrate 1520 of the split-type coil current sensor 1500 can be separated from each other can be utilized to allow for a simpler manufacture of a current sensor with increased sensitivity.

[0137] although Figure 15a The conductor 1550 is shown passing through the current sensor once, but this document discloses a technique that allows the conductor 1550 to pass through the current sensor multiple times directly.

[0138] Figure 16a , Figure 16b , Figure 16c and Figure 16dThe process of winding conductor 1550 around the first portion / substrate 1510 of the split coil is illustrated in four stages, such that the conductor passes through the opening of the coil multiple times when the first and second portions of the coil are closed. During installation, conductor 1550 may be wound around the first portion 1510 of the current sensor. Conductor 1550 may be wound or wrapped around the first portion two or more times.

[0139] Figure 16a The beginning of the process of winding the conductor 1550 around the first substrate 1510 is shown. Figure 16a In the middle, conductor 1550 passes through the first substrate 1510.

[0140] Figure 16b The second stage of the process of winding the conductor 1550 around the first portion / substrate 1510 is shown. The conductor 1550 is twisted, bent, or deformed so that it forms a loop around the first portion / substrate. Since the second portion / substrate 1520 is absent, it is not necessary to pass the conductor through the opening; instead, it can be simply bent or twisted around the substrate 1510.

[0141] Figure 16c The third stage of the process of winding conductor 1550 around the first portion / substrate 1510 is shown. In the third stage, conductor 1330 is further bent or twisted so that it completes one loop around the first portion / substrate 1510.

[0142] Figure 16d The fourth stage of the process of winding the conductor 1550 around the first portion / substrate 1510 is shown. The conductor 1550 is again twisted, bent, or deformed so that it wraps back and passes through the gap in the first portion / substrate 1510 twice, which will form part of the opening when the second portion / substrate 1520 is brought into place.

[0143] like Figure 16e As shown, after the conductor 1550 is wound around the first substrate multiple times, a current sensor 1600 can be formed by combining a first portion / substrate 1510 (with the conductor 1550 wound around it) with a second portion / substrate 1520. The first substrate 1510 and the second substrate 1520 are positioned relative to each other and relative to the conductor 1550 such that the output signals from the first measuring coil 1530 and the second measuring coil 1540 can be used to measure the rate of change of current flowing through the conductor 1550. Winding the conductor in this manner allows the conductor 1550 to be continuously held or clamped during winding. Repeated picking up and releasing of the conductor is not required. Therefore, manufacturing time can be significantly reduced, and the system used to manufacture the winding can be significantly simplified.

[0144] This creates a current sensor in which the conductor 1550 passes through the current sensor 1600 multiple times (i.e., two or more portions of the conductor 1550—four portions in this example—are at least partially surrounded by a combination of the first measuring coil 1530 and the second measuring coil 1540). The more times the conductor 1550 is wound around the first substrate 1510, the higher the sensitivity of the current sensor.

[0145] The first measuring coil 1530 and the second measuring coil 1540 are used to substantially surround or enclose the conductor 1550. For example, the conductor passes between the first substrate 1510 and the second substrate 1520 multiple times. The entire conductor 1550 is not located between the first substrate 1510 and the second substrate 1520; instead, multiple points or portions of the conductor are located between the first substrate 1510 and the second substrate 1520, while the remaining portion of the conductor 1550 is used to wrap around or enclose the first substrate 1510. The first substrate 1510 and the second substrate 1520 are used to substantially surround the conductor 1550 such that at least two portions or points of the conductor 1550 are substantially surrounded by the first measuring coil 1530 and the second measuring coil 1540. The at least two portions or points of the conductor 1550 are not directly adjacent to each other because a portion of the conductor 1550 is located between them, outside the substrates 1510 and 1520.

[0146] By winding the conductor 1550 in this manner, any current flowing through the conductor 1550 flows through the opening 1560 of the current sensor 1600 more than once in a single direction. This achieves an additive combination of induced voltages in the current sensor—effectively measuring the same current multiple times.

[0147] Figures 16a to 16e A conductor 1550 is shown being wound or formed around a first substrate 1510. Alternatively, the conductor 1550 may be wound or formed separately and then positioned above or around the first portion / substrate 1510. During installation, a pre-wound conductor 1550 comprising multiple turns may be positioned above the first portion / substrate 1510 of the current sensor 1500, which includes a first measuring coil 1530. Subsequently, a second substrate 1520 of the current sensor 1500 may be positioned adjacent to the first substrate 1510 such that the first and second portions / substrates substantially surround or encircle at least two portions / points of the conductor 1550.

[0148] Figures 17a to 1 7e shows a current sensor constructed using pre-wound or pre-shaped conductors.

[0149] Figure 17aConductor 1550 is shown. This conductor has been wound to enclose an area. Conductor 1550 can be wound in any suitable manner, such as around any suitable molding die or fixture, such as a molding die having a circular, rectangular, square, or triangular cross-section. The dimensions of the molding die or fixture should be such that the dimensions (such as the width) of the area enclosed by the winding of conductor 1550 are at least the same as the width of the first substrate 1510, and are large enough to allow conductor 1550 to be fitted over or slide onto the first substrate 1510. Conductor 1550 can be wound in the field during installation or in a factory or manufacturing environment. Since conductor 1550 is not wound directly around the first part / substrate 1510, it can be manufactured separately from the first part / second part / substrate 1510 and 1520, or prepared in the field after the first part / second part / substrate 1510 and 1520 have been manufactured.

[0150] Figure 17b The diagram shows a wound conductor 1550 looped over, slid onto, or arranged around the first part / substrate 1510.

[0151] Figure 17c A wound conductor 1550 is shown in its in-place position above the first portion / substrate 1510. The wound conductor 1550 is used to substantially surround or wrap around the first substrate 1510.

[0152] like Figure 17d As shown, after the conductor 1550 is positioned around the first substrate 1510, a current sensor 1700 can be formed by combining the first portion / substrate 1510 (having the conductor 1550 positioned around the first portion / substrate 1510) with the second substrate 1520. The first portion / substrate 1510 and the second portion / substrate 1520 are positioned relative to each other and relative to the conductor 1550, such that the output signal from the first measuring coil 1530 and the output signal from the second measuring coil 1540 can be used to measure the rate of change of current flowing through the conductor 1550.

[0153] Pre-forming the conductor 1550 on a jig or mold can ensure that it is dimensionally correct for the current sensor 1700, and the jig or mold can be shaped to reduce the stress applied to the conductor 1550 during manufacturing.

[0154] although Figure 16e and Figure 17dThe illustrations show current sensors 1600 and 1700 in which the current measuring coil is implemented on a substrate; however, it should be understood that the measuring coil can be implemented in any suitable manner, such as using a toroidal core or a wire-wound measuring coil. In this case, the first substrate 1510 and the second substrate 1520 can be referred to as the first part and the second part of the current sensor. Therefore, this disclosure can be applied to current measuring coils implemented in any manner.

[0155] The first part / substrate 1510, the second part / substrate 1520, and the conductor (whether pre-wound or suitable for winding around the substrate) can be provided in a parts kit for mounting or manufacturing a current sensor. If the conductor is pre-wound, it can be wound around the first part / substrate 1510 in the parts kit, or it can be separate so that it can be looped over the first part / substrate 1510 during mounting.

[0156] Figure 16e and Figure 17d The substrates shown in the current sensors 1600 and 1700 indicate that the first substrate 1510 and the second substrate 1520 have substantially the same size and shape (e.g., each covering a 180-degree angle). However, in an alternative, the first substrate and the second substrate may have different sizes or shapes and cover different angles.

[0157] In other words, the first perimeter or circumferential portion (or the first arc) of the first measuring coil 1530 may be larger than the second perimeter or circumferential portion (or the second arc) around which the second measuring coil 1540 partially surrounds.

[0158] In other words, the angle covered by the first measuring coil 1530 can be greater than the angle covered by the second measuring coil 1540. This allows for greater flexibility in the design of the measuring coils, such as allowing designs to be created to fit a specific space, enabling the measuring coils to be mounted around current-carrying conductors that were previously impossible to mount due to physical space limitations. Since the measuring coils are mounted on the substrate, this can also result in the substrate having different dimensions.

[0159] Furthermore, more than two substrates can be used, with conductors wound around one or more substrates. The substrates can be as described in the reference. Figure 12 Positioning as described. Using more than two substrates can increase sensitivity.

[0160] Each substrate includes a single measuring coil, which, in use, is used to pick up the induced signal caused by the current flowing through the conductor. However, it should be understood that each substrate may include two or more measuring coils.

[0161] The output terminals of the current measuring coils can be coupled to each other, to external measuring circuits, or to active measuring circuits in any suitable manner.

[0162] For example, the first measuring coil 1530 and the second measuring coil 1540 can be passively coupled to each other. The first measuring coil 1530 and the second measuring coil 1540 can be configured to be passively electrically connected to each other to electrically form a single combined coil. For example, each measuring coil can have two ends—one at the beginning of the combined coil and one at the end. The first end of one coil can be passively electrically connected to the first end of the other coil, for example, through a wire or lead. In a specific example, they can be connected to each other using a "spring pin". In this way, the two measuring coils can electrically form a single combined coil, such as a single Rogowski coil, which surrounds or encircles the current-carrying conductor 1550. This allows for simple coil connection. The combined, passively coupled coils can then be coupled to a larger system that includes measurement circuitry comprising any suitable active or passive components, such as buffers, integrators, amplifiers, etc.

[0163] The first measuring coil 1530 and the second measuring coil 1540 can be actively coupled to each other and to a larger system. This can include electronic circuitry on each of the first substrate 1510 and the second substrate 1520, such as reference circuitry. Figures 3 to 12 This can further increase the sensitivity and signal-to-noise ratio of the current sensor 1550, as described in either of the above.

[0164] The term “coupled” as used above includes both direct electrical connections between two components and indirect electrical connections between two components that are electrically connected to each other through one or more intermediate components.

[0165] aspect

[0166] The first set of non-restrictive aspects of this disclosure is set forth in the following numbered clauses.

[0167] 1. A current sensor system for measuring an electrical measurand dependent on a current in a current-carrying conductor, the current sensor system comprising: a first measuring coil; a second measuring coil, wherein the first measuring coil and the second measuring coil are configured to be positioned relative to each other and the current-carrying conductor to at least partially surround the current-carrying conductor; a first electronic circuit including a first input coupled to the first measuring coil and a first output coupled to the measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil and output the first active processing signal from the first output; and a second electronic circuit including a second input coupled to the second measuring coil and a first output coupled to the measuring circuit, the first electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil and output the second active processing signal from the second output, wherein the first active processing signal and the second active processing signal are used to combine to measure an electrical measurand dependent on a current in a current-carrying conductor.

[0168] 2. The current sensor system according to Clause 1, wherein the first electronic circuitry includes a first amplifier configured to generate an amplified version of the first sensor signal, and wherein the second electronic circuitry includes a second amplifier configured to generate an amplified version of the second sensor signal.

[0169] 3. The current sensor system according to Clause 2, wherein the gain of the first amplifier is the same as the gain of the second amplifier.

[0170] 4. The current sensor system according to Clause 2, wherein the gain of the first amplifier is different from the gain of the second amplifier.

[0171] 5. The current sensor system according to any of the preceding clauses, wherein the first electronic circuitry includes a first analog-to-digital converter (ADC) arranged to generate a first digital signal dependent on the first sensor signal, and wherein the second electronic circuitry includes a second analog-to-digital converter (ADC) arranged to generate a second digital signal dependent on the second sensor signal.

[0172] 6. The current sensor system according to any of the preceding clauses, wherein the first electronic circuitry includes a first voltage-to-current converter, wherein the first sensor signal is a voltage signal, and the first voltage-to-current converter is configured to generate a first current signal dependent on the first sensor signal, and wherein the second electronic circuitry includes a second voltage-to-current converter, wherein the second sensor signal is a voltage signal, and the second voltage-to-current converter is configured to generate a second current signal dependent on the second sensor signal.

[0173] 7. The current sensor system according to any of the preceding clauses, the current sensor system further comprising: a combination circuit, the combination circuit being configured to couple the first output terminal of the first electronic circuit to the measurement circuit and to couple the second output terminal of the second electronic circuit to the measurement circuit, wherein the combination circuit is configured to generate a combined signal for output to the measurement circuit by combining the first active processing signal and the second active processing signal.

[0174] 8. The current sensor system according to Clause 7, wherein the combining circuit is a passive circuit configured to passively combine the first active processing signal and the second active processing signal.

[0175] 9. The current sensor system according to Clause 7, wherein the combining circuit is an active circuit configured to actively combine the first active processing signal and the second active processing signal.

[0176] 10. The current sensor system according to Clause 9, wherein the combined circuit includes an amplifier, the amplifier including: an input for receiving the first active processing signal and the second active processing signal; and an output for outputting the first combined signal.

[0177] 11. The current sensor system according to Clause 7, wherein the combining circuitry includes digital circuitry for digitally combining the first active processing signal and the second active processing signal.

[0178] 12. The current sensor system according to any of the preceding clauses, wherein the first measuring coil is formed on a first printed circuit board (PCB), and wherein the second measuring coil is formed on a second PCB.

[0179] 13. The current sensor system according to Clause 12, wherein the first electronic circuit is on the first PCB and the second electronic circuit is on the second PCB.

[0180] 14. The current sensor system according to Clause 12 or Clause 13, wherein the first PCB includes a first clamping mechanism and the second PCB includes a second clamping mechanism, wherein the first clamping mechanism and the second clamping mechanism are configured to engage with each other to hold the first measuring coil and the second measuring coil in place such that they together surround at least a portion of the current-carrying conductor in use.

[0181] 15. The current sensor system according to any of the preceding clauses, further comprising: the measurement circuitry coupled to the first electronic circuitry and the second electronic circuitry, and configured to measure an electrical measurand dependent on the current in the current-carrying conductor based on a combination of the first active processing signal and the second active processing signal.

[0182] 16. A current sensor system according to any of the preceding clauses, wherein the electrical measurement dependent on the current in the current-carrying conductor includes one or more of the following: the rate of change of the current in the current-carrying conductor; the magnitude of the current in the current-carrying conductor; the electrical energy associated with the current in the current-carrying conductor; and the electrical power associated with the current in the current-carrying conductor.

[0183] 17. The current sensor system according to any of the preceding clauses, wherein the first measuring coil is used to cover a first perimeter portion of the current-carrying conductor; and the second measuring coil is used to cover a second perimeter portion of the current-carrying conductor.

[0184] 18. The current sensor system according to Clause 17, wherein the first measuring coil and the second measuring coil are configured such that when they are positioned relative to the current-carrying conductor in use, they together cover a combined perimeter portion of the current-carrying conductor, the combined perimeter portion being larger than each of the first perimeter portion and the second perimeter portion.

[0185] 19. A current sensor system according to Clause 17 or Clause 18, wherein the first perimeter portion and the second perimeter portion have equal dimensions, or the first perimeter portion and the second perimeter portion have different dimensions.

[0186] 20. A measurement system for measuring an electrical measurand that depends on a current in a current-carrying conductor, the measurement system comprising: a combination circuit for coupling to a first measurement coil and a second measurement coil arranged at least partially around the current-carrying conductor, wherein the combination circuit is configured to generate a combination signal by combining: a first active processing signal depending on a first sensor signal output from the first measurement coil; and a second active processing signal depending on a second sensor signal output from the second measurement coil; and a measurement circuit coupled to the combination circuit, wherein the measurement circuit is configured to measure the electrical measurand based on the combination signal.

[0187] 21. An energy meter for measuring electrical energy supplied by a current-carrying conductor, the energy meter comprising: a first measuring coil; a second measuring coil, wherein the first measuring coil and the second measuring coil are configured to be positioned relative to each other and the current-carrying conductor to at least partially surround the current-carrying conductor; a measuring circuit; a first electronic circuit including a first input coupled to the first measuring coil and a first output coupled to the measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil and output the first active processing signal from the first output; and a second electronic circuit including a second input coupled to the second measuring coil and a first output coupled to the measuring circuit, the first electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil and output the second active processing signal from the second output, wherein the measuring circuit is configured to measure the electrical energy based on a combination of the first active processing signal and the second active processing signal.

[0188] 22. The electricity meter according to Clause 21, the electricity meter further comprising a combination circuit arranged to couple the first electronic circuit to the measuring circuit and the second electronic circuit to the measuring circuit, wherein the combination circuit is configured to generate a combined signal for output to the measuring circuit by combining the first active processing signal and the second active processing signal.

[0189] The second set of non-restrictive aspects of this disclosure is set forth in the following numbered clauses.

[0190] 1. A current sensor comprising: a first portion including a first measuring coil; a second portion including a second measuring coil; and a conductor for carrying a current measured by the current sensor, the conductor being wound multiple times around the first portion, wherein the first portion and the second portion are configured to be positioned relative to each other such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor.

[0191] 2. The current sensor according to any of the preceding clauses, wherein: the first portion includes a first electronic circuit, the first electronic circuit including a first input terminal coupled to the first measuring coil and a first output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil and output the first active processing signal from the first output terminal; the second portion includes a second electronic circuit, the second electronic circuit including a second input terminal coupled to the second measuring coil and a second output terminal for coupling to the measuring circuit, the second electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil and output the second active processing signal from the second output terminal, wherein the first active processing signal and the second active processing signal are used to combine to measure an electrical measurand dependent on the current in the current-carrying conductor.

[0192] 3. The current sensor according to Clause 2, wherein the first electronic circuitry includes a first analog-to-digital converter (ADC) arranged to generate a first digital signal dependent on the first sensor signal, and wherein the second electronic circuitry includes a second analog-to-digital converter (ADC) arranged to generate a second digital signal dependent on the second sensor signal.

[0193] 4. The current sensor according to any of the preceding clauses, wherein the first portion and the second portion are configured to be positioned relative to each other such that an opening is formed between the first portion and the second portion.

[0194] 5. The current sensor according to Clause 4, wherein the conductor passes through the opening multiple times.

[0195] 6. The current sensor according to Clause 5, wherein the conductor passes through the opening multiple times, such that the current flowing through the conductor passes through the opening multiple times in a single direction.

[0196] 7. The current sensor according to any of the preceding clauses, wherein the first portion and the second portion are configured to be positioned relative to each other such that the first measuring coil and the second measuring coil together substantially surround at least two non-adjacent portions of the conductor.

[0197] 8. The current sensor according to any of the preceding clauses, wherein when current flows through the conductor, it flows through the at least two portions of the conductor in the same direction.

[0198] 9. The current sensor according to any of the preceding clauses, wherein the first portion and the second portion are positioned relative to each other such that the output signal from the first measuring coil and the output signal from the second measuring coil are used to measure the rate of change of current flowing through the conductor.

[0199] 10. The current sensor according to Clause 9, wherein the output signal from the first measuring coil and the output signal from the second measuring coil depend on the number of portions of the conductor at least partially surrounded by the first measuring coil and the second measuring coil.

[0200] 11. The current sensor according to any of the preceding clauses, wherein the first portion includes a first substrate on which the first measuring coil is formed, and the second portion includes a second substrate on which the second measuring coil is formed.

[0201] 12. The current sensor according to any of the preceding clauses, wherein the first portion of the current sensor is hingedly coupled to the second portion of the current sensor.

[0202] 13. A current sensor comprising: a first portion including: a first measuring coil; a first electronic circuit including a first input terminal coupled to the first measuring coil and a first output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil; a second portion including: a second measuring coil; a second electronic circuit including a second input terminal coupled to the second measuring coil and a second output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil; and a conductor for carrying a current measured by the current sensor, the conductor being wound multiple times around the first portion such that the conductor passes multiple times between the first measuring coil and the second measuring coil.

[0203] 14. The current sensor system according to Clause 13, wherein the first electronic circuitry includes a first amplifier configured to generate an amplified version of the first sensor signal, and wherein the second electronic circuitry includes a second amplifier configured to generate an amplified version of the second sensor signal.

[0204] 15. The current sensor according to Clause 13 or Clause 14, wherein the first electronic circuitry includes a first analog-to-digital converter (ADC) arranged to generate a first digital signal dependent on the first sensor signal, and wherein the second electronic circuitry includes a second analog-to-digital converter (ADC) arranged to generate a second digital signal dependent on the second sensor signal.

[0205] 16. The current sensor according to any one of clauses 13 to 15, the current sensor further comprising a combination circuit for coupling the first output of the first electronic circuit to the measurement circuit and coupling the second output of the second electronic circuit to the measurement circuit, wherein the combination circuit is configured to generate a combined signal for output to the measurement circuit by combining the first active processing signal and the second active processing signal.

[0206] 17. A method of mounting a current sensor, the method comprising: winding a conductor for carrying a current measured by the current sensor around a first portion of the current sensor multiple times, the first portion including a first measuring coil; and positioning a second portion of the current sensor relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor.

[0207] 18. A method of mounting a current sensor, the method comprising: positioning a pre-wound conductor comprising a plurality of turns for carrying a current measured by the current sensor above a first portion of the current sensor, the first portion including a first measuring coil; and positioning a second portion of the current sensor relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor for carrying the current.

[0208] 19. A method of manufacturing a conductor for a current sensor, the method comprising: winding the conductor around a molding die such that the conductor forms a coil comprising a plurality of turns, wherein the molding die is shaped such that the coil is used to fit over a first portion of a current sensor; and removing the conductor from the molding die.

[0209] 20. A component kit for a current sensor, the component kit comprising: a first portion including a first measuring coil; a second portion including a second measuring coil; and a conductor for carrying a current measured by the current sensor, wherein the conductor for carrying the current is wound to form a plurality of turns, and wherein the first portion and the second portion are configured for positioning relative to each other and the conductor such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor.

Claims

1. A current sensor, the current sensor comprising: The first part includes a first measuring coil; The second part includes a second measuring coil; A conductor, which carries the current measured by the current sensor, is wound multiple times around the first portion. The first portion and the second portion are configured to be positioned relative to each other such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor.

2. The current sensor according to any one of the preceding claims, wherein: The first part includes a first electronic circuit, the first electronic circuit including a first input terminal coupled to the first measuring coil and a first output terminal for coupling to a measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil and output the first active processing signal from the first output terminal; The second part includes a second electronic circuit, which includes a second input terminal coupled to the second measuring coil and a second output terminal for coupling to the measuring circuit. The second electronic circuit is configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil and output the second active processing signal from the second output terminal. The first active processing signal and the second active processing signal are used to combine to measure electrical quantities that depend on the current in the current-carrying conductor.

3. The current sensor of claim 2, wherein the first electronic circuitry includes a first analog-to-digital converter (ADC), the first ADC being arranged to generate a first digital signal dependent on the first sensor signal, and The second electronic circuit includes a second analog-to-digital converter (ADC) arranged to generate a second digital signal dependent on the second sensor signal.

4. The current sensor according to any of the preceding claims, wherein the first portion and the second portion are configured to be positioned relative to each other such that an opening is formed between the first portion and the second portion.

5. The current sensor according to claim 4, wherein the conductor passes through the opening multiple times.

6. The current sensor of claim 5, wherein the conductor passes through the opening multiple times, such that the current flowing through the conductor passes through the opening multiple times in a single direction.

7. The current sensor according to any of the preceding claims, wherein the first portion and the second portion are configured to be positioned relative to each other such that the first measuring coil and the second measuring coil together substantially surround at least two non-adjacent portions of the conductor.

8. The current sensor according to any of the preceding claims, wherein when current flows through the conductor, it flows through the at least two portions of the conductor in the same direction.

9. The current sensor according to any of the preceding claims, wherein the first portion and the second portion are positioned relative to each other such that the output signal from the first measuring coil and the output signal from the second measuring coil are used to measure the rate of change of current flowing through the conductor.

10. The current sensor of claim 9, wherein the output signal from the first measuring coil and the output signal from the second measuring coil depend on the number of portions of the conductor at least partially surrounded by the first measuring coil and the second measuring coil.

11. The current sensor according to any of the preceding claims, wherein the first portion includes a first substrate on which the first measuring coil is formed, and the second portion includes a second substrate on which the second measuring coil is formed.

12. The current sensor according to any of the preceding claims, wherein the first portion of the current sensor is hingedly coupled to the second portion of the current sensor.

13. A current sensor, the current sensor comprising: The first part includes: First measuring coil; A first electronic circuit, the first electronic circuit including a first input terminal coupled to the first measuring coil and a first output terminal for coupling to a measuring circuit, the first electronic circuit being configured to generate a first active processing signal based on a first sensor signal received from the first measuring coil; Part Two, Part Two includes: Second measuring coil; A second electronic circuit, the second electronic circuit including a second input terminal coupled to the second measuring coil and a second output terminal for coupling to the measuring circuit, the first electronic circuit being configured to generate a second active processing signal based on a second sensor signal received from the second measuring coil; and A conductor, which carries the current measured by the current sensor, is wound around the first portion multiple times, such that the conductor passes multiple times between the first measuring coil and the second measuring coil.

14. The current sensor system of claim 13, wherein the first electronic circuitry includes a first amplifier configured to generate an amplified version of the first sensor signal, and The second electronic circuit includes a second amplifier configured to generate an amplified version of the second sensor signal.

15. The current sensor of claim 13 or claim 14, wherein the first electronic circuitry includes a first analog-to-digital converter (ADC), the first ADC being arranged to generate a first digital signal dependent on the first sensor signal, and The second electronic circuit includes a second analog-to-digital converter (ADC) arranged to generate a second digital signal dependent on the second sensor signal.

16. The current sensor according to any one of claims 13 to 15, the current sensor further comprising a combination circuit for coupling a first output terminal of the first electronic circuit to the measurement circuit and coupling a second output terminal of the second electronic circuit to the measurement circuit, wherein the combination circuit is configured to generate a combined signal for output to the measurement circuit by combining the first active processing signal and the second active processing signal.

17. A method for installing a current sensor, the method comprising: A conductor for carrying the current measured by the current sensor is wound multiple times around a first portion of the current sensor, the first portion including a first measuring coil; as well as The second portion of the current sensor is positioned relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor.

18. A method for installing a current sensor, the method comprising: A pre-wound conductor comprising multiple turns for carrying the current measured by the current sensor is positioned above a first portion of the current sensor, the first portion including a first measuring coil; as well as The second portion of the current sensor is positioned relative to the first portion of the current sensor such that the first measuring coil and the second measuring coil at least partially surround at least two portions of the conductor for carrying current.

19. A method for manufacturing a conductor for a current sensor, the method comprising: A conductor is wound around a molding die to form a coil comprising multiple turns, wherein the molding die is shaped such that the coil is used to enclose a first portion of an overcurrent sensor; and Remove the conductor from the molding die.

20. A component kit for a current sensor, the component kit comprising: The first part includes a first measuring coil; The second part includes a second measuring coil; A conductor for carrying a current measured by the current sensor, wherein the conductor for carrying the current is wound to form a plurality of turns, and wherein the first portion and the second portion are configured to be positioned relative to each other and the conductor such that the first measuring coil and the second measuring coil together at least partially surround at least two portions of the conductor.

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