Current Sensor with Diagnostic Feature

Abstract

An approach to improving the performance of a current sensor is provided herein. In some embodiments, the device may include a current sensor connected to a busbar, the current sensor includes a coil, the current flowing through the busbar generates a first magnetic field detectable by the current sensor, the coil is operable to generate a second magnetic field, and by orienting the coil, the current sensor receives a portion of the second magnetic field superimposed on the first magnetic field.

Description

Technology Field

[0001] The present disclosure generally relates to the field of circuit protection devices, and in particular to a current sensor having diagnostic characteristics for in-situ feedback. Background Technology

[0002] Current sensors are frequently used in overcurrent protection devices, including short-circuit protection devices. These devices serve as safety elements in critical applications such as electric vehicles (EVs). Current sensors are often factory-calibrated or compensated. However, prior art approaches lack effective in-situ solutions to periodically verify that the current sensor is still in operation and calibrated.

[0003] The present disclosure is provided to relate to these defects and other defects of the prior art. means of solving the problem

[0004] The summary is provided to introduce a selection of concepts in a simplified form, and the concepts are further explained in the detailed description. The summary is not intended to identify the main or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0005] In one approach according to the present disclosure, the apparatus may include a current sensor coupled to a busbar, the current sensor includes a coil, the current flowing through the busbar generates a first magnetic field detectable by the current sensor, the coil is operable to generate a second magnetic field, and by orienting the coil, the current sensor receives a portion of the second magnetic field superimposed on the first magnetic field. Brief explanation of the drawing

[0007] The attached drawings illustrate exemplary approaches of disclosed embodiments devised to date for the practical application of the principle, which are as follows. FIG. 1 illustrates a current sensor assembly according to an embodiment of the present invention; FIG. 2 illustrates a circuit diagram of a current sensor according to an embodiment of the present invention; FIGS. 3 and 4 illustrate the current and magnetic field of a current sensor as a function of time according to an embodiment of the present invention; and FIGS. 5 and 6 illustrate a diagnostic flowchart according to an embodiment of the present invention. The drawings are not necessarily scaled. The drawings are merely representations and are not intended to indicate specific parameters of the disclosure. The drawings are intended to depict typical embodiments of the disclosure and should therefore not be considered as limiting the scope. In the drawings, the same number indicates the same component. Furthermore, in some of the drawings, certain elements may be omitted or unscaled for illustrative clarity. Moreover, some reference numerals may be omitted in certain drawings for clarity. Specific details for implementing the invention

[0008] Sensors, devices, and methods according to the present disclosure will now be described more fully below with reference to the accompanying drawings. Sensors, devices, and methods may be implemented in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure may be thorough and complete and sufficiently convey the scope of systems and methods to those skilled in the art.

[0009] As described herein, embodiments of the present disclosure provide field verification that the current sensor maintains functionality and calibration. Sensor status (e.g., working / not working) and loss of calibration may be reported to a higher-level control system capable of taking appropriate action.

[0010] FIG. 1 illustrates a current sensor assembly (100) (hereinafter "assembly") according to an embodiment of the present invention. Although not limited to, the assembly (100) may be used with a Hall or TMR sensor (not shown). The assembly (100) may include a current sensor (102) coupled to a busbar (104), and the current sensor (102) is a magnetic field ( Bdiag) It includes a coil (108) operable to generate. The busbar (104) may be made of copper or other electrically conductive material. In an alternative embodiment, the current sensor (102) may be coupled to a PCB, the main conductor of the assembly (100) may be a PCB trace, and the diagnostic coil may be constructed by traces on multiple layers of the PCB.

[0011] During use, current flowing through the busbar (104) Isense)It generates a magnetic field (Bsense) detected by a current sensor (102). A value representing the magnetic field can be transmitted to a controller (105) capable of operating with the current sensor (102). By properly orienting the coil (108), the current sensor (102) Bsense It will receive a portion of this magnetic field superimposed on the magnetic field. As illustrated, the coil (108) generally receives the current flowing through the busbar (104). Isense) It can be oriented orthogonally / perpendicularly to the direction of.

[0012] As shown in FIG. 2, the current sensor (102) together with the controller (105) Receive the sum of Bsense + Bdiag, This is converted to the voltage Vsense + Vdiag. In some embodiments, the discriminator (DIS) (112) is Vsense Remove and retain only Viag. By giving a specific invariant position of the coil (108) for the current sensor (102) and setting an appropriate threshold level (VREF), it is possible to determine whether the current sensor (102) is operating properly by comparison.

[0013] FIG. 3 shows the relationship between the current (I) and the magnetic field (B) over time. More specifically, the current ( Idiag) can be a pulsed current for a specific period of time. In this case, Vsense Since the time is determined by referring to Idiag, DIS can separate Vdiag from Vsense. Diagnostics can be performed without sense current (e.g., vehicle parking, part of an initialization sequence) or with sense current (e.g., vehicle driving).

[0014] In Fig. 4, current ( Idiag) can be a periodic current with a specific frequency (i.e., a sinusoidal wave). In this case, VsenseSince the frequency is determined by referencing Idiag, DIS can separate Vdiag from Vsense. Diagnosis can be performed without a sense current (e.g., parked vehicle, part of an initialization sequence) or with a sense current (e.g., vehicle driving).

[0015] FIGS. 5 and 6 show that when the relative position of the diagnostic coil, referenced by the current sensor, is fixed, the diagnosis can be executed at the end of the manufacturing process ("Init(EoLine)"). Vsense_ref and Isense_ref are recorded. Whenever the diagnosis is executed in normal mode, the calibration status can be verified by comparing Vsense with the recorded value (e.g., after applying some modifications based on other factors such as Isense, T).

[0016] For convenience and clarity, this specification uses terms such as "top," "bottom," "upper," "lower," "vertical," "horizontal," "lateral," and "longitudinal" to describe the relative arrangement and orientation of components and parts shown in the drawings. These terms will include specifically mentioned words, derivatives of the words, and words of similar meaning.

[0017] As used herein, an element or action referred to in the singular and followed by the words "a" or "an" should be understood to include plural elements or steps unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the invention are not intended to be limiting. Additional embodiments may also incorporate the mentioned features.

[0018] Furthermore, the terms “substantial” or “substantially,” as well as “approximately” or “approximately,” may be used interchangeably in some embodiments and may be described using any relative measurements acceptable to a person skilled in the art. For example, these terms may serve as a comparison to a reference parameter to indicate a deviation that may provide the intended function. Without limitation, the deviation from the reference parameter may be an amount, for example, less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, etc.

[0019] Although specific embodiments of the present disclosure are described herein, the present disclosure is not limited thereto, because the present disclosure is as broad as the art allows, and the specification can be read likewise. Therefore, the foregoing description should not be interpreted restrictively. Instead, the foregoing description is merely an example of specific embodiments. Those skilled in the art may conceive other modifications within the scope and spirit of the appended claims.

Claims

Claim 1 A device comprising a current sensor connected to a busbar, wherein the current sensor comprises a coil, wherein the coil extends spirally about an axis, the axis being parallel to a plane defined by the upper surface of the busbar, and a current flowing through the busbar generates a first magnetic field detectable by the current sensor, wherein the coil is operable to generate a second magnetic field, and wherein the current sensor receives a portion of the second magnetic field superimposed on the first magnetic field by orienting the coil such that the axis of the coil is perpendicular to the direction of the current flowing through the busbar. Claim 2 delete Claim 3 In claim 1, the controller further comprises a controller capable of operating with the current sensor, wherein the controller receives the sum of the first magnetic field and the second magnetic field, and the sum of the first and second magnetic fields is a voltage Vsense + Vdiag Convert to, and the discriminator removes Vsense and keeps only Vdiag, the device. Claim 4 In paragraph 3, the device is further operable such that the controller determines whether the sensor is operating properly by comparing Vdiag to a selected voltage threshold level. Claim 5 A current sensing device comprising a busbar and a current sensor coupled to the busbar, wherein the current sensor comprises a coil, wherein the coil extends spirally about an axis, and the axis is parallel to a plane defined by the upper surface of the busbar, and a current flowing through the busbar generates a first magnetic field detectable by the current sensor, and the coil is operable to generate a second magnetic field, and by orienting the coil such that the axis of the coil is perpendicular to the direction of the current flowing through the busbar, the current sensor receives a portion of the second magnetic field superimposed on the first magnetic field.

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