Fluxgate current sensor

Abstract

Embodiments of the present disclosure provide techniques for an improved fluxgate current sensor. A fluxgate signal corresponding to the primary current may be received. The fluxgate signal may include at least two stationary periods. Each stationary period may define a plurality of candidate computational windows. An operating condition classification may be generated based on the signal feature set by applying the signal feature set to a classification model. The operating condition may be one of an AC operating condition or a DC operating condition. A computing window may be selected based on the operating condition classification. The plurality of computing windows may include a first computing window and a second computing window. A predicted current value of the primary current may be generated by applying a sampled current value within a selected calculation window for each of the at least two stationary periods to a prediction model.

Description

Technical Field

[0001] This disclosure relates to current sensors, and more specifically to fluxgate current sensor measurements. Some example embodiments are directed to fluxgate current sensors operating under AC conditions. Background Technology

[0002] The applicant has identified numerous technical challenges and difficulties associated with current sensor measurements. Through applied effort, ingenuity, and innovation, the applicant has addressed many of these identified problems by developing embodiments of this disclosure, which are described in detail below. Summary of the Invention

[0003] The various embodiments described herein relate to current sensors, and more specifically to fluxgate current sensor measurements. Some example embodiments relate to fluxgate current sensors operating in alternating current (AC) mode.

[0004] According to one aspect of this disclosure, a method for measuring current using a fluxgate sensor is provided. In some embodiments, the method includes: receiving a fluxgate signal corresponding to a primary current by a controller, wherein the fluxgate signal includes at least two plateau periods, and each plateau period defines a plurality of candidate computation windows; generating an operating condition classification based on the signal feature set by the controller by applying the signal feature set to a classification model, wherein the operating condition classification is one of (i) an AC operating condition indicating an AC primary current or (ii) a DC operating condition indicating a DC primary current; selecting a computation window from the plurality of computation windows by the controller based on the operating condition classification, wherein the plurality of computation windows includes a first computation window and a second computation window; and generating a predicted current value of the primary current by the controller by applying sampled current values ​​within the selected computation window of each of the at least two plateau periods to a prediction model, wherein generating the predicted current value includes generating an average of the sampled current values.

[0005] In some embodiments, fluxgate signals are received from the fluxgate excitation and sampling module.

[0006] In some embodiments, the method further includes generating a signal feature set based on the fluxgate signal by performing analysis on the fluxgate signal.

[0007] In some embodiments, the signal feature set includes (i) peak signal data, (ii) signal variance data, and (iii) periodic data.

[0008] In some embodiments, generating an operating condition classification includes determining: (i) whether the peak signal data meets a peak threshold, (ii) whether the variance data meets a variance threshold, and (iii) whether the periodic data meets a period threshold.

[0009] In some embodiments, generating an operating condition classification further includes generating an operating condition classification as a DC operating condition classification in response to determining that (i) peak signal data fails to meet a peak threshold and (ii) variance data fails to meet a variance threshold.

[0010] In some embodiments, generating an operating condition classification further includes generating an operating condition classification as an AC operating condition classification in response to determining (i) that the peak signal data meets a peak threshold or (ii) that the variance data meets a variance threshold.

[0011] In some embodiments, the classification model is a rule-based model that includes multiple rules, wherein generating an operational condition classification includes comparing a set of signal features with one or more thresholds.

[0012] In some embodiments, selecting a computation window from a plurality of computation windows based on operating condition classification includes selecting a first computation window in response to DC operating condition classification, wherein the first computation window has a length less than the length of each of at least two stationary periods.

[0013] In some embodiments, selecting a computation window from multiple computation windows based on operating condition classification includes selecting a second computation window in response to AC operating condition classification. Attached Figure Description

[0014] The description of the illustrative embodiments can be read in conjunction with the accompanying drawings. It will be appreciated that, for simplicity and clarity of explanation, the elements shown in the drawings are not necessarily drawn to scale unless otherwise described. For example, the dimensions of some elements may be exaggerated relative to others unless otherwise described. Embodiments incorporating the teachings of this disclosure are shown and described with respect to the accompanying drawings presented herein, wherein:

[0015] Figure 1 A block diagram of an example fluxgate current sensor according to at least one embodiment of the present disclosure is provided.

[0016] Figure 2 An example fluxgate signal waveform of the primary current according to at least one example embodiment of the present disclosure is provided.

[0017] Figure 3 Example fluxgate signal waveform comparison diagrams are provided according to at least one example embodiment of the present disclosure.

[0018] Figure 4 A flowchart is provided depicting the operation of an example method for measuring current using a fluxgate current sensor according to at least one embodiment of the present disclosure.

[0019] Figure 5Example fluxgate signals with different frequencies are provided according to at least one example embodiment of the present disclosure. Detailed Implementation

[0020] Some embodiments of this disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, of these embodiments. In fact, these disclosures may be embodied in many different forms and should not be construed as limiting to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The same numerals always refer to the same elements.

[0021] Terms such as “calculate,” “determine,” “generate,” and / or similar words are used interchangeably herein to refer to the creation, modification, or identification of data. Furthermore, the terms “based on,” “partially based on,” “at least based on,” “in accordance with,” and / or similar words are used interchangeably in an opening manner herein, such that they do not indicate that the data is based solely on or only on one or more of the referenced elements, unless so indicated. The same number always refers to the same element.

[0022] As used herein, terms such as “front,” “rear,” “top,” etc., in the examples provided below are for explanatory purposes to describe the relative positions of certain parts or portions of parts. Furthermore, as will be apparent to those skilled in the art based on this disclosure, the terms “substantially” and “approximately” indicate that the referenced element or related description is accurate within applicable engineering tolerances.

[0023] As used herein, the term “comprising” means including but not limited to, and should be interpreted in the manner in which it is typically used in the patent context. The use of broader terms such as including, comprising, and having should be understood to support narrower terms such as consisting of, substantially consisting of, and substantially consisting of.

[0024] The phrases “in one embodiment”, “according to one embodiment”, etc., generally mean that a particular feature, structure or characteristic following the phrase may be included in at least one embodiment of this disclosure, and may be included in more than one embodiment of this disclosure (importantly, such phrases do not necessarily refer to the same embodiment).

[0025] The terms “example” or “exemplary” are used herein to mean “served as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as advantageous or preferred over other implementations.

[0026] If the specification states that a component or feature "may," "can," "possibly," "should," "will," "preferably," "possibly," "usually," "optionally," "for example," "often," or "maybe" (or other such language) be included or have that characteristic, then the particular component or feature does not need to be included or have that characteristic. Such components or features may be optionally included in some embodiments, or they may be excluded.

[0027] As used herein, unless otherwise indicated, the term “or” is used in the sense of substitution and connection between two. The terms “illustrative” and “example” are used as examples without an indication of quality level. Terms such as “calculate,” “determine,” “generate,” and / or similar words are used interchangeably herein to refer to the creation, modification, or identification of data. Furthermore, the terms “based on,” “partially based on,” “at least based on,” “in accordance with,” and / or similar words are used interchangeably in an opening manner herein such that they do not indicate that they are based solely on or only on one or more of the referenced elements unless so indicated. The same number always refers to the same element.

[0028] Fluxgate is a current sensing technology that can be used in a variety of current measurement applications, including current measurement in electric vehicles (EVs) and energy storage systems (ESS). Fluxgate current sensors can be used to measure direct current (DC) and / or alternating current (AC). For example, many applications may involve measuring both DC primary current and AC primary current. For instance, many electric vehicles include DC primary currents such as those for DC charging and discharging, as well as AC primary currents such as those for PTC, charging AC harmonics, etc. Such complex applications may require battery pack current sensors (e.g., in electric vehicles or other devices / systems) to accurately measure not only DC but also accurately detect AC primary current. Therefore, there is a need for robust current sensing capable of accurately measuring both DC and AC primary currents.

[0029] Figure 1 This is a block diagram of an example fluxgate current sensor 100 according to at least one embodiment of the present disclosure. Figure 1 As shown, the fluxgate current sensor 100 includes: a magnetic core 104, a coil 106, a fluxgate oscillation circuit 108, a sampling resistor 110, an amplifier 112, an analog-to-digital converter (ADC) 114, and a controller 116. In some embodiments, the fluxgate oscillation circuit 108, the sampling resistor 110, the amplifier 112, and / or the ADC 114 may collectively define the fluxgate excitation and sampling module of the fluxgate current sensor 100. For example, the fluxgate excitation and sampling module of the fluxgate current sensor 100 may include the fluxgate oscillation circuit 108, the sampling resistor 110, the amplifier 112, and / or the ADC 114.

[0030] The magnetic core 104 can be circular, such as an example circular toroid. A coil 106 is wound around the magnetic core 104 and includes two ends 122 connected to a fluxgate oscillator circuit 108. The fluxgate oscillator circuit 108 is also connected to a sampling resistor 110. At this point, the coil 106 is connected to the sampling resistor 110. In some embodiments, and as... Figure 1 As shown, coil 106 is connected in series with a sampling resistor. For example, sampling resistor 110 may be a low-resistance resistor connected in series with fluxgate oscillator circuit 108. Fluxgate oscillator circuit 108 circulates coil 106 (e.g., forward and backward) to create an excitation signal on coil 106, thereby generating an excitation current, such as a periodic signal, in coil 106.

[0031] In some embodiments, the fluxgate oscillator circuit 108 includes an H-bridge circuit configured to generate a periodic excitation signal. The characteristics of the excitation signal (e.g., the oscillation period and plateau amplitude of the excitation signal) may be affected by the voltage from the power supply 118 (e.g., the drive voltage), the magnitude of the primary current 124, and / or the inductance of the coil 106.

[0032] In various embodiments, an excitation signal on coil 106 (e.g., corresponding to an excitation current on coil 106) is sampled, and the sampled excitation signal is processed (e.g., signal processing) to measure the current value of primary current 124. In various embodiments, sampling and processing the excitation signal includes sampling and processing the voltage signal 120 of sampling resistor 110. For example, the voltage signal 120 of sampling resistor 110 may correspond to the excitation signal. As described above, in some embodiments, sampling resistor 110 is connected in series with sampling resistor 110, so that the current flowing through sampling resistor 110 is the same as the current flowing through coil 106. In this respect, in some embodiments, fluxgate current sensor 100 detects the voltage signal 120 of sampling resistor 110 (e.g., based on the characteristics of easily saturated inductance) and processes the voltage signal 120 to determine the current value of primary current 124. The sampled signal may be referred to herein as a fluxgate signal.

[0033] In various embodiments, amplifier 112 is configured to amplify the voltage signal 120 of sampling resistor 110. For example, processing the excitation signal may include amplifier 112 receiving the voltage signal 120 and outputting the amplified voltage signal 120 (which may be interchangeably referred to herein as a fluxgate signal) to controller 116. As shown, in Figure 1In this configuration, amplifier 112 can output an amplified voltage signal 120 to controller 116 via ADC 114. In some embodiments, controller 116 is configured to calculate the current value of primary current 124 (e.g., the current to be measured). In some embodiments, controller 116 is a microcontroller.

[0034] In some embodiments, controller 116 includes a processor, memory, input / output circuitry, and / or communication circuitry to perform and implement one or more operations described herein with respect to fluxgate current sensor 100. For example, controller 116 may include a set of circuitry that may include a processor, memory, input / output circuitry, and / or communication circuitry. For example, controller 116 may include a processor configured to process the signal output by ADC 114, including calculating the current value of primary current 124. In some embodiments, memory is configured to store software and / or firmware configured to provide instructions, such as computer instructions or computer code, in conjunction with the processor and other circuitry to process the signal output by ADC 114, including calculating the current value of primary current 124. In some embodiments, controller 116 may use communication circuitry to communicate with other devices. As an example, communication circuitry includes one or more communication components that enable communication between fluxgate current sensor 100 (e.g., its controller 116) and other devices. As a non-limiting example, one or more communication components may include a Controller Area Network (CAN) bus, which enables communication between the fluxgate current sensor 100 (e.g., its controller 116) and other devices. The controller 116 may, for example, include a CAN bus (e.g., including CAN low and / or CAN high) to enable communication with other devices.

[0035] In some embodiments, the term "circuit" includes hardware, and in some embodiments includes software for configuring the hardware. For example, in some embodiments, a circuit includes processing circuitry, storage media, a network interface, input / output devices, etc. Alternatively or additionally, in some embodiments, other elements of the controller 116 provide or supplement the functionality of a particular set of circuitry. For example, in some embodiments, the processor provides processing functionality to any set of circuitry, the memory provides storage functionality to any set of circuitry, the communication circuitry provides network interface functionality to any set of circuitry, and so on.

[0036] In some embodiments, controller 116 may be embodied as one or more complex programmable logic devices (CPLDs), microprocessors, multi-core processors, coprocessor entities, application-specific instruction set processors (ASIPs), and / or microcontrollers. In some embodiments, controller 116 may be embodied as integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), hardware accelerators, digital circuits, etc.

[0037] In some embodiments, the fluxgate current sensor 100 and / or a portion thereof may be embodied by one or more systems and / or devices.

[0038] Figure 2 An example fluxgate signal waveform 200 for the current to be measured according to at least one example embodiment of this disclosure is provided. Specifically, Figure 2 An example acquisition period of a fluxgate signal (e.g., reflecting the excitation current on coil 106) generated by fluxgate oscillator circuit 108 is provided. The fluxgate signal waveform 200 (e.g., the acquisition period of the fluxgate signal) may include (multiple) saturation-desaturation regions (e.g., at least one saturation and desaturation region) and (multiple) plateau periods. As shown, in Figure 2 In some embodiments, the fluxgate signal waveform 200 includes at least three saturation-desaturation regions 204A-C (e.g., unstable regions) and at least two stable periods 210A, 210B. For example, the acquisition period of the fluxgate signal represented in the fluxgate signal waveform may include a first saturation-desaturation region 204A, a second saturation-desaturation region 204B, and a third saturation-desaturation region 204C. Additionally, the fluxgate signal waveform 200 (e.g., the acquisition period of the fluxgate signal represented therein) may include a first stable period 210A and a second stable period 210B. In some examples, the amplitude of the first stable period 210A and / or the second stable period 210B may be varied.

[0039] In some embodiments, a plateau period (e.g., plateau periods 210A, 210B) is a region between two consecutive saturation-desaturation regions (e.g., between 204A and 204B, and between 204B and 204C). The plateau period may have a predetermined length. In some embodiments, the length of the plateau period may reflect a substantially stable region within the acquisition period of the fluxgate signal.

[0040] Figure 3 Example fluxgate signal waveform comparison diagram 300 is provided according to at least one example embodiment of the present disclosure. Specifically, Figure 3Example fluxgate signal waveform 300A for DC current type and example fluxgate signal waveform 300B for AC current type are shown. Such fluxgate signal waveform 300A may be referred to herein as DC fluxgate signal waveform 300A. Fluxgate signal waveform 300A represents the acquisition period of a first fluxgate signal corresponding to DC current, and fluxgate signal waveform 300B represents the acquisition period of a second fluxgate signal corresponding to AC current. Such fluxgate signal waveform 300B may be referred to herein as AC fluxgate signal waveform 300B.

[0041] In some embodiments, the steady-state period defines multiple computation windows (e.g., multiple candidate computation windows). In some embodiments, the multiple computation windows include a first computation window, such as a first computation window 330A and a second computation window 330B. In some embodiments, and as in... Figure 3 As shown, the first calculation window 330A has a length shorter than the length of the stationary period, and the second calculation window 330B has a length substantially the same as the length of the stationary period. In this respect, the first calculation window 330A has a shorter length relative to the length of the second calculation window.

[0042] In some embodiments, the controller 116 is configured to determine operating conditions associated with the fluxgate current sensor 100 and to select a calculation window from a plurality of calculation windows based on the operating conditions. In some embodiments, the operating conditions refer to the type of primary current signal of the current being measured (e.g., DC primary current or AC primary current). For example, a DC operating condition may indicate a DC primary current signal, and an AC operating condition may indicate an AC primary current signal.

[0043] In some embodiments, controller 116 is configured to select a first calculation window in response to determining that the signal is an interference signal. In some embodiments, controller 116 is configured to select a first calculation window in response to determining that the operating conditions are DC operating conditions, and to select a second calculation window in response to determining that the operating conditions are AC operating conditions. For example, during the steady periods 210A and 210B of the DC fluxgate signal waveform 300A, the fluxgate signal (e.g., its sampled value) can be minimized so that when the primary current signal is a DC primary current, the length of the calculation window has little significant impact on the calculated current value. For example, during the steady periods 210A and 210B of the DC fluxgate signal waveform 300A, interference signals can couple into the saturation-desaturation regions 204A-C (e.g., indicating unstable regions). Furthermore, for DC operating conditions with a short calculation window, interference immunity can be improved without affecting the accuracy of the calculated current value (e.g., the calculated value of the primary current).

[0044] On the other hand, during the stable periods 210A and 210B of the AC fluxgate signal waveform 300B, the fluxgate signal may change significantly, causing the calculation window to have a significant impact on the calculated current value. For example, excluding region 320 from the calculation window during the stable period may lead to inaccurate calculated current values. For instance, the average value of the signal in region 320 will not be included in the calculated current value, therefore, signal changes in region 320 will not be reflected in the calculated current value, and the accuracy of the calculated current value will be affected.

[0045] In some embodiments, the controller 116 uses a classification model and determines the classification of operating conditions based on a set of signal features. In some embodiments, the classification model is a rule-based model. For example, in some embodiments, the classification model includes a set of rules. Each rule may include one or more rule conditions defined at least in part by one or more characteristics of the fluxgate signal during a stationary period (and / or a relevant plateau period) and a corresponding threshold.

[0046] In some embodiments, the controller 116 generates a signal feature set by performing analysis on the fluxgate signal. In some embodiments, performing analysis on the fluxgate signal includes extracting data from the fluxgate signal and analyzing and / or processing the extracted data. In some embodiments, the fluxgate signal and / or the extracted data can be applied to one or more analysis models to generate the signal feature set. In some embodiments, the analysis model may include one or more mathematical models.

[0047] In some embodiments, the signal feature set includes peak signal data, signal variance data, and period data. In some embodiments, the peak signal data includes peak values ​​during a first and / or second stationary period (e.g., peak value P1 in the first stationary period 210A and / or peak value P2 in the second stationary period 210B). In some embodiments, the signal variance data includes variance values ​​during the first and / or second stationary periods (e.g., variance V1 in the first stationary period 210A and / or variance V2 in the second stationary period 210B). In some embodiments, the period data includes the number of periods during the first and / or second stationary periods (e.g., the number of signal periods in the first stationary period 210A and / or the number of signal periods C2 in the second stationary period 210B).

[0048] For example, the peak value of the DC fluxgate signal in the steady-state periods 210A and 210B may be smaller than the peak value of the AC fluxgate signal in the steady-state periods 210A and 210B, and conversely, the peak value of the AC fluxgate signal in the steady-state periods 210A and 210B may be larger than the peak value of the DC fluxgate signal in the steady-state periods 210A and 210B. Furthermore, the variance (e.g., a measure of change) of the DC fluxgate signal in the steady-state periods 210A and 210B may be smaller than the peak value of the AC fluxgate signal in the steady-state periods 210A and 210B, and conversely, the variance of the AC fluxgate signal in the steady-state periods 210A and 210B may be larger than the variance of the DC fluxgate signal in the steady-state periods 210A and 210B. Additionally, the amplitude of the AC fluxgate signal (e.g., the AC sampled signal) may vary periodically, and the number of cycles per unit length plateau period may correspond to the signal period on the primary side.

[0049] In some embodiments, one or more rule conditions include a first condition that evaluates the peak values ​​(P1, P2) of each of the first stationary period 210A and the second stationary period 210B against a threshold P to determine whether the corresponding peak value is greater than the threshold P. In some embodiments, one or more rule conditions include a second condition that evaluates the variance values ​​(V1, V2) of each of the first stationary period 210A and the second stationary period 210B against a threshold V to determine whether the variance is greater than the threshold V. In some embodiments, one or more rule conditions include a third condition that evaluates the periodic data (C1, C2) of each of the first stationary period 210A and the stationary period 210B against a threshold C to determine whether the periodic data is greater than the threshold C.

[0050] In some embodiments, controller 116 (e.g., using a classification model) is configured to determine that the fluxgate signal is an interference signal in response to determining that at least two of the rule conditions are met. For example, the fluxgate signal may be asymmetric when at least two of the rule conditions indicating an interference signal are met. In some embodiments, controller 116 (e.g., using a classification model) is configured to determine that the fluxgate signal is a stable signal in response to determining that none of the rule conditions are met.

[0051] In some embodiments, the controller 116 (e.g., using a classification model) is configured to generate a DC operation classification (e.g., classifying the operation condition as a DC operation condition) in response to determining that each of the first and second conditions is not met. For example, in response to determining that the peak value during a stationary period (e.g., the first and / or the second stationary period) is less than a corresponding peak value threshold and the variance during a stationary period (e.g., the first and / or the second stationary period) is less than a corresponding variance threshold, the controller may determine that the operation condition is a DC operation condition (e.g., indicating a DC primary signal). In some embodiments, the controller 116 may be configured to first determine whether the fluxgate signal is stable before generating a DC operation classification.

[0052] In some embodiments, controller 116 (e.g., using a classification model) is configured to generate an AC operating condition classification (e.g., classifying the operating condition as an AC operating condition) in response to determining that at least one of a first condition or a second condition is met. For example, controller 116 may determine that the operating condition is an AC operating condition (e.g., indicating an AC primary signal) in response to determining that a peak value during a plateau period (e.g., a first and / or a second plateau period) is greater than a corresponding peak threshold or that a variance during a plateau period (e.g., a first and / or a second plateau period) is greater than a corresponding variance threshold.

[0053] In some embodiments, to avoid unexpected fluctuations that may affect the classification of operating conditions, a predetermined minimum number of sampling times is accumulated during the switching between DC and AC operating conditions. For example... Figure 5 As shown, for example, multiple signals 504A-E at different frequencies can be used.

[0054] In some embodiments, controller 116 is configured to calculate the value of the primary current by performing the operation in Equation 1 below:

[0055]

[0056] Equation 1

[0057] In equation 1, I p It can represent the calculated current value of the primary current; ∑Plateau1 can represent the average current value within the selected calculation window of the first stable period of 210A; ∑Plateau1 can represent the sum of the sampled current values ​​within the selected calculation window of the first stable period; Count Plateau1 It can represent the size of the calculation window during the plateau period associated with the first stable period; ∑Plateau2 can represent the average current value in the selected calculation window of the second stable period 210B; ∑Plateau2 can represent the sum of the sampled current values ​​in the selected calculation window of the first stable period; and Count Plateau2 It can represent the size of the calculation window during the plateau period associated with the second stationary period.

[0058] In some embodiments, controller 116 is configured to calculate Count by performing the operations in Equation 2 below. Plateau1 And calculate Count by performing the operations in Equation 3 below. Plateau2 .

[0059] Count Plateau1 =Ratio * Plateau1Length

[0060] Equation 2

[0061] Count Plateau2 =Ratio * Plateau2Length

[0062] Equation 3

[0063] In equations 2 and 3 above, Count Plateau1 and Count Plateau2 Each can represent a calculation window for the plateau period associated with the first plateau period and a calculation window for the plateau period associated with the second plateau period, respectively. In some embodiments, the ratios in Equations 2 and 3 above are constants for the DC primary current. In some embodiments, the controller 116 is configured to calculate the ratios of the AC primary current in Equations 2 and 3 by performing the operations in Equation 4 below.

[0064]

[0065] Equation 4

[0066] Where a can represent gain; b can represent offset; C1 can represent the number of cycles per unit length of plateau period of the signal period associated with the first stable period and corresponding to the primary current; and C2 can represent the number of cycles per unit length of plateau period of the signal period associated with the second stable period and corresponding to the primary current. For example, the stable period under AC operating conditions (e.g., under AC signal) can be dynamically adjusted using the signal period of the primary current.

[0067] Figure 4 The illustration shows a flowchart depicting the operation of an example method for measuring current using a fluxgate current sensor according to at least one embodiment. Specifically, Figure 4 An example method 400 for an improved fluxgate current sensor under AC operating conditions is depicted. In some embodiments, method 400 is performed by one or more specially configured computing devices, such as means embodying the fluxgate current sensor, either alone or in communication with one or more other components, devices, systems, etc. In some embodiments, the means includes a fluxgate current sensor 100. In some embodiments, the means communicates with one or more external devices, systems, devices, etc., to perform one or more of the depicted and described operations.

[0068] Although example method 400 depicts a specific sequence of operations, the order may be changed without departing from the scope of this disclosure. For example, some of the depicted operations may be performed in parallel or in a different order without substantially affecting the functionality of method 400. In other examples, different components of the example device or system implementing method 400 may perform their functions substantially simultaneously or in a specific order.

[0069] According to some examples, method 400 includes receiving a fluxgate signal at block 402. For example, controller 116 may receive the fluxgate signal from the fluxgate excitation and sampling module of fluxgate current sensor 100. The fluxgate excitation and sampling module may include a fluxgate oscillator circuit (e.g., an H-bridge, etc.), a sampling resistor, an amplifier, and / or an ADC. The fluxgate signal may correspond to a primary current and may include at least two stable periods. Each of the at least two stable periods may define multiple candidate calculation windows. In some embodiments, the calculation window refers to a portion of the fluxgate signal that includes the sampled signal (e.g., representing the sampled current).

[0070] According to some examples, method 400 includes generating a signal feature set at block 404. For example, controller 116 can generate a signal feature set based on a fluxgate signal by performing analysis on the fluxgate signal. In some embodiments, performing analysis on the fluxgate signal includes extracting data from the fluxgate signal and analyzing and / or processing the extracted data. In some embodiments, the fluxgate signal and / or the extracted data can be applied to one or more analysis models to generate the signal feature set. In some embodiments, the analysis model may include one or more mathematical models.

[0071] In some embodiments, the signal feature set includes peak signal data, signal variance data, and period data. In some embodiments, the peak signal data includes peak values ​​of the first and second stable periods (e.g., peak value P1 in the first stable period and / or peak value P2 in the second stable period). In some embodiments, the signal variance data includes variance values ​​of the first and second stable periods (e.g., variance V1 in the first stable period and / or variance V2 in the second stable period). In some embodiments, the period data includes the number of periods of the first and second stable periods (e.g., the number of signal periods in the first stable period and / or the number of signal periods C2 in the second stable period).

[0072] According to some examples, method 400 includes generating an operating condition classification at block 404. For example, controller 116 can generate an operating condition classification based on a signal feature set by applying the signal feature set to a classification model. In some embodiments, the operating condition is one of an AC operating condition indicating an AC primary current or a DC operating condition indicating a DC primary current. In some embodiments, the classification model is a rule-based model that includes multiple rules. In some embodiments, generating the operating condition classification includes comparing the signal feature set with one or more thresholds.

[0073] In some embodiments, generating an operating condition classification includes determining whether: (i) peak signal data meets a peak threshold, (ii) variance data meets a variance threshold, and / or (iii) periodic data meets a period threshold. In some embodiments, generating an operating condition classification includes generating an operating condition classification as a DC operating condition classification in response to determining that (i) peak data fails to meet a peak threshold and (ii) variance data fails to meet a variance threshold. In some embodiments, generating an operating condition classification includes generating an operating condition classification as an AC operating condition classification in response to determining that (i) peak data meets a peak threshold or (ii) variance data meets a variance threshold.

[0074] In some embodiments, when the peak value during a steady period (e.g., a first and / or a second steady period) is less than the corresponding peak value threshold, the peak signal data fails to meet the peak value threshold. In some embodiments, when the variance during a steady period (e.g., a first and / or a second steady period) is less than the corresponding variance value threshold, the variance data fails to meet the variance value threshold.

[0075] In some embodiments, the peak signal data satisfies the peak threshold when the peak value during a steady period (e.g., the first and / or the second steady period) is greater than the corresponding peak threshold. In some embodiments, the variance data satisfies the variance threshold when the variance during a steady period (e.g., the first and / or the second steady period) is greater than the corresponding variance threshold.

[0076] According to some examples, method 400 includes selecting a computation window at box 406. For example, controller 116 may select a computation window from multiple computation windows based on operating condition classification. For example, the computation window may change dynamically according to different operating conditions. In some embodiments, the multiple computation windows include a first computation window and a second computation window. In some embodiments, selecting a computation window from multiple computation windows based on operating condition classification includes selecting a first computation window in response to a DC operating condition classification. In some embodiments, selecting a computation window from multiple computation windows based on operating condition classification includes selecting a second computation window in response to an AC operating condition classification. In some embodiments, the first computation window has a length smaller than the length of the second computation window. In some embodiments, the first computation window has a length smaller than the length of each of at least two steady-state periods.

[0077] According to some examples, method 400 includes generating a predicted current value for the primary current at block 408. For example, controller 116 can generate the predicted current value for the primary current by applying sampled current values ​​within a selected calculation window for each of at least two steady-state periods to a prediction model. In some embodiments, generating the predicted current value includes generating an average of the sampled current values. For example, controller 116 can perform the operation shown in Equation 1 above. In some embodiments, the prediction model can define the operation in Equation 1.

[0078] in conclusion

[0079] Benefiting from the teachings presented in the foregoing description and associated drawings, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other embodiments of the present disclosure set forth herein. Therefore, it is to be understood that the embodiments are not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Furthermore, while the foregoing description and associated drawings have described exemplary embodiments in the context of certain example combinations of elements and / or functions, it should be appreciated that alternative embodiments may provide different combinations of elements and / or functions without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated, as may be set forth in some of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

[0080] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any disclosure or potentially claimed matter, but rather as descriptions of features specific to particular embodiments of a particular disclosure. Certain features described herein in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, while features may be described above as functioning in certain combinations, and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and the claimed combination may be for sub-combinations or variations thereof.

[0081] Similarly, although operations are described in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed in the specific order shown or in a sequential order, or requiring the execution of all shown operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single product or packaged into multiple products.

[0082] Therefore, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0083] Furthermore, while this detailed description has set forth some embodiments of the present disclosure, the appended claims may cover other embodiments of the present disclosure that differ from the described embodiments, based on various modifications and improvements. Moreover, within the appended claims, unless the specific terms “means for…” or “steps for…” are used within a given claim, the claims are not intended to be interpreted according to 35 U.S.SC §112, paragraph (f).

Claims

1. A method for measuring current using a fluxgate current sensor, the method comprising: The controller receives a fluxgate signal corresponding to the primary current, wherein the fluxgate signal includes at least two stationary periods, and each stationary period defines multiple candidate calculation windows; The controller generates an operating condition classification based on the signal feature set by applying the signal feature set to a classification model, wherein the operating condition classification is one of (i) an AC operating condition indicating AC primary current or (ii) a DC operating condition indicating DC primary current. The controller selects a calculation window from multiple calculation windows based on the classification of the operating conditions, wherein the multiple calculation windows include a first calculation window and a second calculation window; and The controller generates a predicted current value for the primary current by applying the sampled current value within a selected calculation window for each of the at least two stable time periods to the prediction model, wherein generating the predicted current value includes generating an average of the sampled current values.

2. The method according to claim 1, wherein, Receive fluxgate signals from the fluxgate excitation and sampling module.

3. The method according to claim 1 further includes generating a signal feature set based on the fluxgate signal by performing analysis on the fluxgate signal.

4. The method according to claim 3, wherein the signal feature set includes (i) peak signal data, (ii) signal variance data, and (iii) periodic data.

5. The method of claim 4, wherein generating the operating condition classification includes determining: (i) whether the peak signal data satisfies a peak threshold; (ii) whether the variance data satisfies a variance threshold; and (iii) whether the periodic data satisfies a periodic threshold.

6. The method of claim 5, wherein generating the operating condition classification further comprises generating the operating condition classification as a DC operating condition classification in response to determining (i) that the peak signal data fails to meet the peak threshold and (ii) that the variance data fails to meet the variance threshold.

7. The method of claim 5, wherein generating the operating condition classification further comprises generating the operating condition classification as an AC operating condition classification in response to determining (i) that the peak signal data satisfies the peak threshold or (ii) that the variance data satisfies the variance threshold.

8. The method of claim 1, wherein the classification model is a rule-based model comprising multiple rules, wherein generating the operational condition classification comprises comparing the signal feature set with one or more thresholds.

9. The method of claim 1, wherein selecting the computation window from the plurality of computation windows based on the operating condition classification includes selecting the first computation window in response to the DC operating condition classification, wherein the first computation window has a length less than the length of each of the at least two stationary periods.

10. The method of claim 1, wherein selecting a calculation window from a plurality of calculation windows based on operating condition classification includes selecting a second calculation window in response to AC operating condition classification.

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