Current measurement method, current sensor and sensing equipment

Abstract

The invention discloses a current measurement method, a current sensor and sensing equipment, and relates to the technical field of current measurement, and the current sensor comprises a first magnetic resistance sensing unit and a second magnetic resistance sensing unit which are symmetrically arranged. Acquiring a corresponding relation between the output signal of the current sensor and the load current in the wire; 2, acquiring a first output signal of the first magnetic resistance sensing unit and a second output signal of the second magnetic resistance sensing unit according to the current load current in the wire; 3, performing arithmetic mean value operation on the first output signal and the second output signal to obtain a third output signal; and 4, obtaining the current load current of the wire according to the third output signal and the corresponding relation. The corresponding relation between the load current and the third output signal is established and recorded, and the third output signal is calibrated through the corresponding relation, so that automatic compensation is realized, and the detection precision is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of current measurement, and in particular to a current measurement method, a current sensor and a sensing device. Background Art

[0002] An open-loop current sensor is a common current measurement device, mainly used to detect AC or DC current in a conductor. Currently, the open-loop current sensor has a simple structure and directly measures the magnetic field or magnetic flux generated by the current to determine the current in the conductor. However, the open-loop current sensor has low measurement accuracy when measuring current and is easily disturbed by external magnetic fields.

[0003] Therefore, it is necessary to provide a current measurement method, a current sensor and a sensing device to solve the above technical problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a current measurement method, a current sensor and a sensing device, aiming to improve the technical problem of low accuracy of open-loop sensors when detecting current in the prior art.

[0005] To achieve the above object, according to one aspect of the present invention, the present invention provides a current measurement method of a current sensor, wherein the current sensor comprises a first magnetoresistive sensing unit and a second magnetoresistive sensing unit which are symmetrically arranged, and the current measurement method comprises the following steps:

[0006] Acquiring a corresponding relationship between an output signal of the current sensor and a load current in the wire;

[0007] Acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit according to a current load current in the wire;

[0008] Obtain a third output signal by performing arithmetic mean operation on the first output signal and the second output signal;

[0009] The current load current of the wire is obtained according to the third output signal and the corresponding relationship.

[0010] In one embodiment, obtaining the corresponding relationship between the output signal of the current sensor and the load current in the wire comprises the following steps:

[0011] According to different load currents passing through the wire, obtaining different first test signals of the first magnetoresistive sensing unit and different second test signals of the second magnetoresistive sensing unit;

[0012] Acquire a first measurement relationship according to the first test signal and the load current, and acquire a second measurement relationship according to the second test signal and the load current;

[0013] A corresponding relationship between the output signal of the current sensor and the load current is determined according to the first measurement relationship and the second measurement relationship.

[0014] In one embodiment, the first output signal of the first magnetoresistive sensor unit is proportional to the differential signal of the first magnetoresistive sensor unit; the second output signal of the second magnetoresistive sensor unit is proportional to the differential signal of the second magnetoresistive sensor unit.

[0015] In one embodiment, the first output signal is related to the maximum measurable current value and the maximum voltage of the current sensor; the second output signal is related to the maximum measurable current value and the maximum voltage of the current sensor.

[0016] In one embodiment, obtaining the first output signal of the first magnetoresistive sensing unit and the second output signal of the second magnetoresistive sensing unit according to the current load current in the wire comprises the following steps:

[0017] Rotate the current sensor to sequentially obtain output signals of the first magnetoresistance sensing unit at an original position, a 90-degree position, a 180-degree position, and a 270-degree position, and output signals of the second magnetoresistance sensing unit at an original position, a 90-degree position, a 180-degree position, and a 270-degree position;

[0018] Taking the arithmetic mean of the output signals of the first magnetoresistive sensing unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position as the first output signal of the first magnetoresistive sensing unit;

[0019] The arithmetic average of the output signals of the second magnetoresistive sensor unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position is taken as the second output signal of the second magnetoresistive sensor unit.

[0020] According to another aspect of the present invention, the present invention further provides a current sensor, wherein the current sensor applies the current measurement method described above, comprising:

[0021] A magnetic concentrating ring module, wherein the magnetic concentrating ring module is provided with a channel for accommodating the wire and a first open air gap and a second open air gap which are centrally symmetrical;

[0022] A magnetoresistive sensing module, the magnetoresistive sensing module comprising a first magnetoresistive sensing unit and a second magnetoresistive sensing unit, the first magnetoresistive sensing unit being arranged at the first open air gap, and the second magnetoresistive sensing unit being arranged at the second open air gap;

[0023] A signal processing module, the signal processing module includes an acquisition unit and a determination unit; the acquisition unit is used to acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit, and obtain a third output signal of the current sensor by performing an arithmetic average operation on the first output signal and the second output signal; the determination unit is used to acquire a corresponding relationship between the output signal of the current sensor and the load current;

[0024] The determining unit is further configured to determine a current current of the wire according to the third output signal and the corresponding relationship.

[0025] In one embodiment, the acquisition unit is further used to acquire a first measurement relationship between a first test signal of the first magnetoresistive sensing unit and a load current of the conductor, and to acquire a second measurement relationship between a second test signal of the second magnetoresistive sensing unit and a load current of the conductor;

[0026] The determining unit is used to determine a corresponding relationship between the output signal of the current sensor and the load current according to the first measurement relationship and the second measurement relationship.

[0027] In one embodiment, the signal processing module further includes:

[0028] A first ASIC unit, the first ASIC unit is electrically coupled to the first magnetoresistive sensing unit, and is used to obtain a differential signal of the first magnetoresistive sensing unit and calibrate it into the first output signal:

[0029] The second ASIC unit is electrically coupled to the second magnetoresistive sensing unit and is used to obtain the differential signal of the second magnetoresistive sensing unit and calibrate the differential signal into the second output signal.

[0030] In one embodiment, the signal processing module further includes a temperature compensation unit, and the temperature compensation unit is used to compensate for output signals of the first magnetoresistive sensing unit and the second magnetoresistive sensing unit.

[0031] According to another aspect of the present invention, the present invention further provides a sensor device, which applies the above-mentioned current measurement method, or includes the above-mentioned current sensor.

[0032] In the above solution, the current sensor includes a first magnetoresistive sensing unit and a second magnetoresistive sensing unit that are symmetrically arranged, and the current measurement method includes the following steps:

[0033] Obtaining the corresponding relationship between the output signal of the current sensor and the load current in the wire;

[0034] Acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit according to a current load current in the conductor;

[0035] Obtain a third output signal by performing an arithmetic mean operation on the first output signal and the second output signal;

[0036] The current load current of the wire is obtained according to the third output signal and the corresponding relationship.

[0037] Specifically, different load currents first pass through the conductor, and the current sensor outputs different signals. Then, the corresponding relationship between the load current and the output signal of the current sensor is obtained, which is equivalent to establishing a corresponding curve diagram between the load current and the output signal of the current sensor. After the corresponding relationship is obtained, in the actual measurement process, according to the current load current in the conductor, the first magnetoresistance sensing unit obtains a first output signal, and the second magnetoresistance sensing unit obtains a second output signal. Then, the first output signal and the second output signal are calculated by arithmetic mean to obtain a third output signal. According to the third output signal, the corresponding relationship between the output signal of the current sensor and the load current in the conductor that is pre-established is brought into. If the third output signal exists in the database in the corresponding relationship, the load current data of the corresponding relationship will be directly output. If the third output signal does not exist in the database in the corresponding relationship, the database that is closest to the third output signal in the corresponding relationship will be searched, and then the load current data of the corresponding relationship will be directly output. In this way, automatic compensation is achieved, which greatly improves the accuracy of the current detection method. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of a flow chart of a first embodiment of a current measurement method provided by the present invention;

[0040] Figure 2 A schematic diagram of a flow chart of a second embodiment of a current measurement method provided by the present invention;

[0041] Figure 3 This is a flow chart of a third embodiment of the current measurement method provided by the present invention.

[0042] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] An open-loop current sensor is a common current measurement device, mainly used to detect AC or DC current in a conductor. Currently, the open-loop current sensor has a simple structure and directly measures the magnetic field or magnetic flux generated by the current to determine the current in the conductor. However, the open-loop current sensor has low measurement accuracy when measuring current and is easily disturbed by external magnetic fields.

[0047] According to one aspect of the present invention, see Figure 1 , Figure 1 The present invention provides a flow chart of a first embodiment of a current measurement method provided by the present invention. The present invention provides a current measurement method of a current sensor, wherein the current sensor comprises a first magnetoresistive sensing unit and a second magnetoresistive sensing unit which are symmetrically arranged. The current measurement method comprises the following steps:

[0048] S1, obtaining the corresponding relationship between the output signal of the current sensor and the load current in the wire;

[0049] First, different load currents pass through the wire, and the current sensor outputs different signals. Then, the corresponding relationship between the load current and the output signal of the current sensor is obtained, which is equivalent to establishing a corresponding curve graph between the load current and the output signal of the current sensor.

[0050] S2, obtaining a first output signal of the first magnetoresistance sensing unit and a second output signal of the second magnetoresistance sensing unit according to a current load current in the wire;

[0051] According to the current load current in the wire, the first magnetoresistive sensing unit obtains a first output signal, and the second magnetoresistive sensing unit obtains a second output signal.

[0052] S3, obtaining a third output signal by performing arithmetic mean operation on the first output signal and the second output signal;

[0053] The third output signal is obtained by performing arithmetic mean operation on the first output signal and the second output signal. Since the first magnetoresistive sensing unit and the second magnetoresistive sensing unit are symmetrically arranged, the data calculated in this way can improve the accuracy of the measurement structure.

[0054] S4. Obtain the current load current of the wire according to the third output signal and the corresponding relationship.

[0055] According to the third output signal, the correspondence between the output signal of the current sensor and the load current in the wire is pre-established. When the third output signal is consistent with the output signal of the current sensor recorded previously, the corresponding load current data will be directly output. When the third output signal is inconsistent with the output signal of the current sensor recorded previously, the output signal closest to the output signal of the current sensor recorded previously will be found, and then the corresponding load current data will be directly output.

[0056] In this embodiment, different load currents first pass through the conductor, and the current sensor outputs different signals. Then, the corresponding relationship between the load current and the output signal of the current sensor is obtained, which is equivalent to establishing a corresponding curve diagram between the load current and the output signal of the current sensor. After the corresponding relationship is obtained, in the actual measurement process, according to the current load current in the conductor, the first magnetoresistance sensing unit obtains a first output signal, and the second magnetoresistance sensing unit obtains a second output signal. Then, the first output signal and the second output signal are calculated by arithmetic mean to obtain a third output signal. According to the third output signal, the corresponding relationship between the output signal of the current sensor and the load current in the conductor is brought into the pre-established corresponding relationship. If the third output signal exists in the database in the corresponding relationship, the load current data of the corresponding relationship will be directly output. If the third output signal does not exist in the database in the corresponding relationship, the third output signal closest to the database in the corresponding relationship will be found, and then the load current data of the corresponding relationship will be directly output. In this way, automatic compensation is achieved, which greatly improves the accuracy of the current detection method.

[0057] See also Figure 2 , Figure 2 This is a flow chart of a second embodiment of the current measurement method provided by the present invention. In one embodiment, obtaining the corresponding relationship between the output signal of the current sensor and the load current in the wire includes the following steps:

[0058] S11, obtaining different first test signals of the first magnetoresistance sensing unit and different second test signals of the second magnetoresistance sensing unit according to different load currents passing through the wire;

[0059] First, different load currents pass through the wire, and the first magnetoresistance sensor unit outputs different first test signals under different load currents, and the second magnetoresistance sensor unit also outputs different second test signals under different load currents.

[0060] S12, obtaining a first measurement relationship according to the first test signal and the load current, and obtaining a second measurement relationship according to the second test signal and the load current;

[0061] Then, based on these first test signals and the corresponding load currents, a first measurement relationship between the first test signal of the first magnetoresistance sensor unit and the load current is determined, which is equivalent to establishing a corresponding curve graph between the load current and the first test signal of the first magnetoresistance sensor unit, as well as a second measurement relationship between the second test signal of the second magnetoresistance sensor unit and the load current, which is equivalent to establishing a corresponding curve graph between the load current and the second test signal of the second magnetoresistance sensor unit.

[0062] S13. Determine a corresponding relationship between the output signal of the current sensor and the load current according to the first measurement relationship and the second measurement relationship.

[0063] The arithmetic mean values ​​of the first test signal and the second test signal obtained under each load current are calculated, so that the correspondence between the output signal of the current sensor and the load current in the wire is obtained, which is equivalent to establishing a corresponding curve diagram between the load current and the output signal of the current sensor.

[0064] In this embodiment, different load currents are first passed through the conductor, and the first magnetoresistance sensor unit outputs different first test signals under different load currents, and the second magnetoresistance sensor unit also outputs different second test signals under different load currents. Then, based on these first test signals and the corresponding load currents, a first measurement relationship between the first test signal of the first magnetoresistance sensor unit and the load current is determined, which is equivalent to establishing a corresponding curve diagram between the load current and the first test signal of the first magnetoresistance sensor unit, and a corresponding curve diagram between the second test signal and the load current, and a second measurement relationship between the second test signal of the second magnetoresistance sensor unit and the load current is confirmed, which is equivalent to establishing a corresponding curve diagram between the load current and the first test signal of the first magnetoresistance sensor unit. The arithmetic mean value of the first test signal and the second test signal obtained under each load current is calculated, so that the correspondence between the output signal of the current sensor and the load current in the wire is obtained, which is equivalent to establishing a corresponding curve diagram of the load current and the output signal of the current sensor; in this way, in subsequent measurements, according to the current load current in the wire, the first magnetoresistance sensor unit obtains an output signal, and then the first output signal is obtained according to the relationship between the output signal of the first magnetoresistance sensor unit and the load current confirmed above, that is, when this output signal is consistent with the output signal of the first magnetoresistance sensor unit recorded previously, the corresponding first output signal will be directly output, and when this output signal is consistent with the previously recorded When the output signal of the first magnetoresistance sensing unit is inconsistent, the closest output signal will be searched, and then the first output signal corresponding to the output signal will be directly output; the second magnetoresistance sensing unit obtains an output signal, and then the second output signal is obtained according to the aforementioned confirmed relationship between the output signal of the second magnetoresistance sensing unit and the load current, that is, when the output signal is consistent with the previously recorded output signal of the second magnetoresistance sensing unit, the corresponding second output signal will be directly output; when the output signal is inconsistent with the previously recorded output signal of the second magnetoresistance sensing unit, the closest output signal will be searched, and then the second output signal corresponding to the output signal will be directly output; then the first output signal The third output signal is obtained by arithmetic mean calculation of the first output signal and the second output signal, and the third output signal is brought into the pre-established correspondence between the output signal of the current sensor and the load current in the wire. If the third output signal exists in the database in the correspondence, the load current data of the corresponding relationship will be directly output; if the third output signal does not exist in the database in the correspondence, the database closest to the third output signal in the correspondence will be found, and then the load current data of the corresponding relationship will be directly output. Through this method, the accuracy of the first output signal and the second output signal can be compensated, thereby ensuring the accuracy of the third output signal, and further improving the accuracy of current detection.

[0065] In one embodiment, the first output signal of the first magnetoresistance sensing unit is proportional to the differential signal of the first magnetoresistance sensing unit; the second output signal of the second magnetoresistance sensing unit is proportional to the differential signal of the second magnetoresistance sensing unit. Specifically, the differential signal refers to the resistance difference between two adjacent magnetoresistance elements, that is, the resistance difference between the first magnetoresistance sensing unit and the second magnetoresistance sensing unit. By measuring the differential signal instead of the absolute resistance value of a single magnetoresistance element, the influence of common mode noise can be effectively reduced. Common mode noise is noise that affects all magnetoresistance elements at the same time. The first magnetoresistance sensing unit and the second magnetoresistance sensing unit are symmetrically arranged, and the differential signal measurement inside the first magnetoresistance sensing unit and the second magnetoresistance sensing unit is also symmetrical. This layout helps to further offset the interference of the external magnetic field. The external magnetic field has the same effect on the symmetrically arranged first magnetoresistance sensor unit and the second magnetoresistance sensor unit, so these external interferences will be offset each other when calculating the differential signal; there is a linear relationship between the differential signal and the load current, because the differential signal reflects the relative change of the magnetic field change, rather than the change of the absolute value. The first magnetoresistance sensor unit outputs a differential signal under the current load current, the first ASIC unit receives the differential signal and calibrates the differential signal to the first output signal through the previously acquired corresponding relationship, and the second magnetoresistance sensor unit outputs a differential signal under the current load current, the second ASIC unit receives the differential signal and calibrates the differential signal to the second output signal through the previously acquired corresponding relationship; there is usually a better linear relationship between the differential signal and the load current, and this linear relationship makes it easier to establish and calibrate the corresponding relationship between the output signals of the first magnetoresistance sensor unit and the second magnetoresistance sensor unit and the load current, thereby improving the accuracy and consistency of the measurement.

[0066] In one embodiment, the first output signal is related to the maximum measurable current value and the maximum voltage of the current sensor; the second output signal is related to the maximum measurable current value and the maximum voltage of the current sensor. Specifically, the maximum measurable current value and the maximum voltage of the current sensor are the properties of the current sensor itself, that is, they are known when they are manufactured. By associating the first output signal and the second output signal with the maximum measurable current value, it can be ensured that the sensor can accurately measure in a wide current range, which means that the current sensor can measure not only small currents but also large currents, thereby expanding its scope of application; the first output signal and the second output signal are related to the maximum voltage, which can prevent the current sensor from being damaged when its maximum operating voltage is exceeded. By limiting the maximum values ​​of the first output signal and the second output signal, the internal circuit can be protected from overvoltage damage and the service life of the current sensor can be extended; associating the first output signal and the second output signal with the maximum measurable current value and the maximum voltage can help establish a more linear output characteristic. This linear relationship makes it easier to establish and calibrate the correspondence between the output signal and the load current, thereby improving the accuracy and consistency of the measurement.

[0067] See also Figure 3 , Figure 3 The present invention provides a flow chart of a third embodiment of the current measurement method. In one embodiment, obtaining a first output signal of a first magnetoresistive sensing unit and a second output signal of a second magnetoresistive sensing unit according to a current load current in a conductor includes the following steps:

[0068] S21, rotating the current sensor, sequentially acquiring output signals of the first magnetoresistance sensing unit at the original position, 90 degree position, 180 degree position and 270 degree position, and output signals of the second magnetoresistance sensing unit at the original position, 90 degree position, 180 degree position and 270 degree position;

[0069] During detection, the current sensor is placed in the original position for detection. The first magnetoresistance sensor unit and the second magnetoresistance sensor unit both output the first signal. Then the current sensor is rotated 90 degrees, 180 degrees and 270 degrees respectively. At each position, the first magnetoresistance sensor unit and the second magnetoresistance sensor unit both output a signal, and the above signals are recorded.

[0070] S22, taking the arithmetic average of the output signals of the first magnetoresistive sensing unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position as the first output signal of the first magnetoresistive sensing unit;

[0071] The output signals of the first magnetoresistive sensor unit at various positions recorded previously are subjected to an arithmetic average operation, and the obtained value is the first output signal of the first magnetoresistive sensor under the current load current.

[0072] S23, taking the arithmetic mean of the output signals of the second magnetoresistive sensor unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position as the second output signal of the second magnetoresistive sensor unit.

[0073] The output signals of the second magnetoresistive sensor unit at various positions recorded previously are subjected to an arithmetic average operation, and the obtained value is the second output signal of the second magnetoresistive sensor under the current load current.

[0074] In this embodiment, during detection, the current sensor is first placed in the original position for detection, and the first magnetoresistance sensor unit and the second magnetoresistance sensor unit both output the first signal, and then the current sensor is rotated, and the current sensor is rotated 90 degrees, 180 degrees and 270 degrees respectively. At each position, the first magnetoresistance sensor unit and the second magnetoresistance sensor unit both output a signal, and the above-mentioned signals are recorded, and then the output signals of the first magnetoresistance sensor unit and the second magnetoresistance sensor unit at each position are respectively arithmetic averaged, and the two values ​​calculated in this way are the first output signal of the first magnetoresistance sensor unit and the second output signal of the second magnetoresistance sensor unit; detecting the first output signal of the first magnetoresistance sensor unit and the second output signal of the second magnetoresistance sensor unit by such a method can greatly improve the accuracy of the first output signal and the second output signal, so that the third output signal obtained by the first output signal and the second output signal will also be more accurate, which can greatly improve the detection accuracy of the current sensor.

[0075] According to another aspect of the present invention, the present invention further provides a current sensor, which applies the above-mentioned current measurement method, including:

[0076] A magnetic concentrating ring module, wherein the magnetic concentrating ring module is provided with a channel for accommodating the wire and a first open air gap and a second open air gap which are centrally symmetrical;

[0077] A magnetoresistive sensing module, the magnetoresistive sensing module comprising a first magnetoresistive sensing unit and a second magnetoresistive sensing unit, the first magnetoresistive sensing unit being arranged at a first open air gap, and the second magnetoresistive sensing unit being arranged at a second open air gap;

[0078] A signal processing module, the signal processing module includes an acquisition unit and a determination unit; the acquisition unit is used to acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit, and obtain a third output signal of the current sensor by performing an arithmetic average operation on the first output signal and the second output signal; the determination unit is used to acquire a corresponding relationship between the output signal of the current sensor and the load current;

[0079] The determination unit is further configured to determine a current current of the wire according to the third output signal and the corresponding relationship.

[0080] Specifically, different load currents first pass through the conductor, and the current sensor outputs different signals, and the determination unit will obtain the corresponding relationship between the load current and the output signal of the current sensor, which is equivalent to establishing a corresponding curve diagram of the load current and the output signal of the current sensor; after obtaining the corresponding relationship, in the actual measurement process, according to the current load current in the conductor, the first magnetoresistance sensing unit obtains the first output signal, the second magnetoresistance sensing unit obtains the second output signal, the acquisition unit obtains the first output signal and the second output signal, and then the first output signal and the second output signal are calculated by arithmetic mean to obtain the third output signal, and the confirmation unit brings the third output signal into the pre-established corresponding relationship between the output signal of the current sensor and the load current in the conductor. If the third output signal exists in the database in the corresponding relationship, the load current data of the corresponding relationship will be directly output, and if the third output signal does not exist in the database in the corresponding relationship, the database will be searched for the closest third output signal in the corresponding relationship, and then the load current data of the corresponding relationship will be directly output, so that automatic compensation is achieved, and the accuracy of the current detection method is greatly improved.

[0081] In one embodiment, the acquisition unit is further used to acquire a first measurement relationship between a first test signal of the first magnetoresistance sensor unit and a load current of the conductor, and to acquire a second measurement relationship between a second test signal of the second magnetoresistance sensor unit and a load current of the conductor;

[0082] The determination unit is used for determining the corresponding relationship between the output signal of the current sensor and the load current according to the first measurement relationship and the second measurement relationship.

[0083] Specifically, different load currents first pass through the conductor, and the first magnetoresistance sensing unit outputs different first test signals under different load currents, and the second magnetoresistance sensing unit also outputs different second test signals under different load currents. The acquisition unit acquires these first test signals and the corresponding load currents, and the second test signals and the corresponding load currents. Then, the confirmation unit confirms the first measurement relationship between the first test signal of the first magnetoresistance sensing unit and the load current, and the second measurement relationship between the second test signal of the second magnetoresistance sensing unit and the load current, which is equivalent to establishing a corresponding curve diagram between the load current and the first test signal of the first magnetoresistance sensing unit, and equivalent to establishing a corresponding curve diagram between the load current and the second test signal of the second magnetoresistance sensing unit. The arithmetic mean value of the first test signal and the second test signal obtained under each load current is calculated, so that the correspondence between the output signal of the current sensor and the load current in the conductor is obtained, which is equivalent to establishing a corresponding curve diagram between the load current and the output signal of the current sensor. In this way, in subsequent measurements, according to the current load current in the conductor, the first magnetoresistance sensing unit obtains an output signal, and then according to the previous The first output signal is obtained according to the relationship between the output signal of the first magnetoresistance sensor unit and the load current confirmed above, that is, when the output signal is consistent with the output signal of the first magnetoresistance sensor unit recorded before, the corresponding first output signal will be directly output, and when the output signal is inconsistent with the output signal of the first magnetoresistance sensor unit recorded before, the closest output signal will be found, and then the first output signal corresponding to the output signal will be directly output; the second magnetoresistance sensor unit obtains an output signal, and then the second output signal is obtained according to the relationship between the output signal of the second magnetoresistance sensor unit and the load current confirmed above, that is, when the output signal is consistent with the output signal of the second magnetoresistance sensor unit recorded before, the corresponding second output signal will be directly output, and when the output signal is inconsistent with the output signal of the second magnetoresistance sensor unit recorded before, the closest output signal will be found, and then the second output signal corresponding to the output signal will be directly output; through this method, the first output signal and the second output signal can be compensated for accuracy, thereby ensuring the accuracy of the third output signal, and further improving the accuracy of current detection.

[0084] In one embodiment, the signal processing module further includes:

[0085] A first ASIC unit, the first ASIC unit is electrically coupled to the first magnetoresistive sensing unit, and is used to obtain a differential signal of the first magnetoresistive sensing unit and calibrate it into a first output signal:

[0086] The second ASIC unit is electrically coupled to the second magnetoresistive sensing unit and is used to obtain the differential signal of the second magnetoresistive sensing unit and calibrate the differential signal into a second output signal.

[0087] Specifically, there is a linear relationship between the differential signal and the load current, because the differential signal reflects the relative change of the magnetic field rather than the change of the absolute value. The first magnetoresistance sensing unit outputs a differential signal under the current load current, the first ASIC unit receives the differential signal and calibrates the differential signal to a first output signal through the previously acquired correspondence relationship, the second magnetoresistance sensing unit outputs a differential signal under the current load current, the second ASIC unit receives the differential signal and calibrates the differential signal to a second output signal through the previously acquired correspondence relationship; the differential signal and the load current usually have a better linear relationship, and this linear relationship makes it easier to establish and calibrate the correspondence between the output signals of the first magnetoresistance sensing unit and the second magnetoresistance sensing unit and the load current, thereby improving the accuracy and consistency of the measurement.

[0088] In one embodiment, the signal processing module further includes a temperature compensation unit, which is used to compensate the output signals of the first magnetoresistance sensing unit and the second magnetoresistance sensing unit. The output signals of the first magnetoresistance sensing unit and the second magnetoresistance sensing unit will be affected by temperature, thereby affecting the measurement accuracy of the current sensor. By setting the temperature compensation unit, the first magnetoresistance sensing unit and the second magnetoresistance sensing unit perform temperature compensation, which can avoid the influence of temperature on the first magnetoresistance sensing unit and the second magnetoresistance sensing unit as much as possible, thereby ensuring the accuracy of the output signals of the first magnetoresistance sensing unit and the second magnetoresistance sensing unit, and greatly improving the measurement accuracy of the current sensor.

[0089] According to another aspect of the present invention, the present invention further provides a sensor device, which applies the above-mentioned current measurement method, or includes the above-mentioned current sensor. Since the sensor device includes all implementation methods of all embodiments of the above-mentioned current sensor or the above-mentioned current measurement method, it at least has all the beneficial effects brought by all the above-mentioned implementation methods, which will not be repeated here one by one.

[0090] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A current measurement method of a current sensor, characterized in that: The current sensor comprises a first magnetoresistive sensing unit and a second magnetoresistive sensing unit which are symmetrically arranged, and the current measurement method comprises the following steps: Acquiring a corresponding relationship between an output signal of the current sensor and a load current in the wire; Acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit according to a current load current in the wire; Obtain a third output signal by performing arithmetic mean operation on the first output signal and the second output signal; The current load current of the wire is obtained according to the third output signal and the corresponding relationship.

2. The current measurement method according to claim 1, characterized in that: The obtaining of the corresponding relationship between the output signal of the current sensor and the load current in the wire comprises the following steps: According to different load currents passing through the wire, obtaining different first test signals of the first magnetoresistive sensing unit and different second test signals of the second magnetoresistive sensing unit; Acquire a first measurement relationship according to the first test signal and the load current, and acquire a second measurement relationship according to the second test signal and the load current; A corresponding relationship between the output signal of the current sensor and the load current is determined according to the first measurement relationship and the second measurement relationship.

3. The current measurement method according to claim 1, characterized in that: The first output signal of the first magnetoresistance sensing unit is proportional to the differential signal of the first magnetoresistance sensing unit; the second output signal of the second magnetoresistance sensing unit is proportional to the differential signal of the second magnetoresistance sensing unit.

4. The current measurement method according to claim 3, characterized in that: The first output signal is related to the maximum measurable current value and the maximum voltage of the current sensor; the second output signal is related to the maximum measurable current value and the maximum voltage of the current sensor.

5. The current measurement method according to claim 1, characterized in that: The step of obtaining the first output signal of the first magnetoresistive sensing unit and the second output signal of the second magnetoresistive sensing unit according to the current load current in the wire comprises the following steps: Rotate the current sensor to sequentially obtain output signals of the first magnetoresistance sensing unit at an original position, a 90-degree position, a 180-degree position, and a 270-degree position, and output signals of the second magnetoresistance sensing unit at an original position, a 90-degree position, a 180-degree position, and a 270-degree position; Taking the arithmetic mean of the output signals of the first magnetoresistive sensing unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position as the first output signal of the first magnetoresistive sensing unit; The arithmetic average of the output signals of the second magnetoresistive sensor unit at the original position, the 90-degree position, the 180-degree position and the 270-degree position is taken as the second output signal of the second magnetoresistive sensor unit.

6. A current sensor, wherein the current sensor applies the current measurement method according to any one of claims 1 to 5, characterized in that: include: A magnetic concentrating ring module, wherein the magnetic concentrating ring module is provided with a channel for accommodating the wire and a first open air gap and a second open air gap which are centrally symmetrical; A magnetoresistive sensing module, the magnetoresistive sensing module comprising a first magnetoresistive sensing unit and a second magnetoresistive sensing unit, the first magnetoresistive sensing unit being arranged at the first open air gap, and the second magnetoresistive sensing unit being arranged at the second open air gap; A signal processing module, the signal processing module includes an acquisition unit and a determination unit; the acquisition unit is used to acquire a first output signal of the first magnetoresistive sensing unit and a second output signal of the second magnetoresistive sensing unit, and obtain a third output signal of the current sensor by performing an arithmetic average operation on the first output signal and the second output signal; the determination unit is used to acquire a corresponding relationship between the output signal of the current sensor and the load current; The determining unit is further configured to determine a current current of the wire according to the third output signal and the corresponding relationship.

7. The current sensor according to claim 6, characterized in that: The acquisition unit is further used to acquire a first measurement relationship between a first test signal of the first magnetoresistive sensing unit and a load current of the conductor, and to acquire a second measurement relationship between a second test signal of the second magnetoresistive sensing unit and a load current of the conductor; The determining unit is used to determine a corresponding relationship between the output signal of the current sensor and the load current according to the first measurement relationship and the second measurement relationship.

8. The current sensor according to claim 6, characterized in that: The signal processing module also includes: A first ASIC unit, the first ASIC unit is electrically coupled to the first magnetoresistive sensing unit, and is used to obtain a differential signal of the first magnetoresistive sensing unit and calibrate it into the first output signal: The second ASIC unit is electrically coupled to the second magnetoresistive sensing unit and is used to obtain the differential signal of the second magnetoresistive sensing unit and calibrate the differential signal into the second output signal.

9. The current sensor according to claim 6, characterized in that: The signal processing module further includes a temperature compensation unit, and the temperature compensation unit is used to compensate the output signals of the first magnetoresistive sensing unit and the second magnetoresistive sensing unit.

10. A sensing device, characterized in that: The sensing device applies the current measurement method described in any one of claims 1 to 5, or includes the current sensor described in any one of claims 6 to 9.

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