Wide range current measurement circuit and wide range current measurement method

Abstract

The present disclosure provides a wide-range current measurement circuit and a wide-range current measurement method. The wide-range current measurement circuit comprises a TMR current sensor array, a range switching circuit and a switch switching circuit. The TMR current sensor array comprises N TMR current sensors, each of which is used to detect the current of a current lead to be measured, and the range of each TMR current sensor is different. The range switching circuit outputs N control signals according to the current measurement values of the N TMR current sensors. The switch switching circuit comprises N switches, and the switch switching circuit controls the conduction and disconnection of the N switches according to the N control signals to control the gating of the N TMR current sensors. The wide-range current measurement circuit provided by the present disclosure can realize fast response and accurate switching of different ranges during wide-range current detection, and can also realize high-precision and high-sensitivity detection of wide-range current.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular to a wide-range current measurement circuit and a wide-range current measurement method. Background Art

[0002] There are usually many types of currents in the power grid system. These currents are of various types and have a wide range of current amplitude distribution. The current amplitude range is as low as uA level and as high as MA level. In order to achieve comprehensive and comprehensive detection of various currents in the power grid system, there are current sensor modules with different principles and functions in the power grid system. Related technologies often use a current sensor that connects a Hall sensor and a magnetoresistive current sensor in series to achieve detection of currents with a large current amplitude distribution span, that is, a wide range. Among them, the Hall sensor can achieve detection of currents in a large range, and the magnetoresistive current sensor can achieve detection of currents in a small range. The current sensor integrates the current measurement results of the Hall sensor and the magnetoresistive current sensor based on the processing circuit to achieve detection of currents in a wide range.

[0003] In the process of implementing the concepts of this disclosure, the inventors discovered at least the following problems in the related art: Current sensors in the related art suffer from poor performance, including low sensitivity, slow response speed, and susceptibility to limitations in current amplitude and frequency ranges. They are also unable to achieve high-precision detection of currents over a wide range. Summary of the Invention

[0004] In view of the above problems, the present disclosure provides a wide-range current measurement circuit and a wide-range current measurement method.

[0005] According to a first aspect of the present disclosure, a wide-range current measurement circuit is provided, comprising a TMR current sensor array, a range switching circuit, and a switch switching circuit. The TMR current sensor array comprises N TMR current sensors, each of which is configured to detect the current of a current conductor to be measured, and each of the N TMR current sensors has a different range. The range switching circuit is configured to output N control signals based on the current measurement values ​​of each of the N TMR current sensors. The switch switching circuit comprises N switches, configured to control the on and off states of the N switches based on the N control signals, thereby controlling the gating of each of the N TMR current sensors, wherein N is a positive integer.

[0006] According to an embodiment of the present disclosure, the measuring range of each of the N TMR current sensors is determined based on the distance between each of the N TMR current sensors and the current conductor to be measured.

[0007] According to an embodiment of the present disclosure, the above-mentioned range switching circuit includes N-1 comparators, wherein the positive input terminal of the i-th comparator is connected to the i-th TMR current sensor, and the negative input terminal of the i-th comparator is used to receive the i-th reference voltage, wherein i is a positive integer and i≤N-1.

[0008] According to an embodiment of the present disclosure, the above-mentioned range switching circuit also includes a decoder, which outputs the above-mentioned N control signals based on the output results of the above-mentioned N-1 comparators. The above-mentioned decoder includes N-1 input terminals and N output terminals. The i-th input terminal of the above-mentioned decoder is connected to the output terminal of the above-mentioned i-th comparator, and the j-th output terminal of the above-mentioned decoder is connected to the j-th switch of the above-mentioned switch switching circuit, wherein j is a positive integer and j≤N.

[0009] According to an embodiment of the present disclosure, the j-th switch of the switch switching circuit is connected to the j-th TMR current sensor of the TMR current sensor array.

[0010] According to an embodiment of the present disclosure, when the outputs of the N-1 comparators of the range switching circuit are all "0", the decoder outputs a first control signal, the first switch of the switch switching circuit is turned on, and the remaining N-1 switches of the switch switching circuit are turned off;

[0011] When the outputs of the first i comparators of the range switching circuit are all "1" and the outputs of the remaining N-1-i comparators of the range switching circuit are all "0", the decoder outputs the i+1th control signal, the i+1th switch of the switch switching circuit is turned on, and the remaining N-1 switches of the switch switching circuit are turned off;

[0012] When the outputs of the above-mentioned N-1 comparators of the above-mentioned range switching circuit are all "1", the above-mentioned decoder outputs the Nth control signal, the Nth switch of the above-mentioned switch switching circuit is turned on, and the remaining N-1 switches of the above-mentioned switch switching circuit are all turned off.

[0013] According to an embodiment of the present disclosure, the wide-range current measurement circuit further includes a programmable gain amplifier circuit, which is connected to the switch switching circuit and is used to amplify the current measurement value according to the respective selections of the N TMR current sensors.

[0014] According to an embodiment of the present disclosure, the programmable gain amplifier circuit includes N amplification switches and N load resistors, and the N amplification switches are used to control the on and off of the N load resistors.

[0015] According to an embodiment of the present disclosure, when the outputs of the N-1 comparators of the range switching circuit are all "0", the decoder outputs a first control signal, the first amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit are all turned off;

[0016] When the outputs of the first i comparators of the range switching circuit are all “1” and the outputs of the remaining N-1-i comparators of the range switching circuit are all “0”, the decoder outputs the i+1th control signal, the i+1th amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 switches of the programmable gain amplifier circuit are turned off;

[0017] When the outputs of the above-mentioned N-1 comparators of the above-mentioned range switching circuit are all "1", the above-mentioned decoder outputs the Nth control signal, the above-mentioned decoder outputs the i+1th control signal, the Nth amplification factor switch of the above-mentioned programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the above-mentioned programmable gain amplifier circuit are all turned off.

[0018] A second aspect of the present disclosure provides a wide-range current measurement method. The wide-range current measurement method includes:

[0019] detecting the current of the current conductor to be measured by using a plurality of TMR current sensors to obtain current measurement values ​​of each of the plurality of TMR current sensors, wherein the plurality of TMR current sensors each have a different measuring range;

[0020] outputting a plurality of control signals based on the current measurement values ​​of the plurality of TMR current sensors through a range switching circuit; and

[0021] The switch switching circuit controls the on and off of the plurality of switches based on the plurality of control signals, so as to control the gating of the plurality of TMR current sensors.

[0022] According to the wide-range current measurement circuit and wide-range current measurement method provided by the present disclosure, the wide-range current measurement circuit includes a TMR current sensor array, a range switching circuit, and a switch switching circuit. The TMR current sensor array includes N TMR current sensors, each of which is used to detect the current of a current conductor to be measured, and each of the N TMR current sensors has a different range. The range switching circuit outputs N control signals based on the current measurement values ​​of each of the N TMR current sensors. The switch switching circuit includes N switches, which control the conduction and disconnection of the N switches based on the N control signals to control the selection of each of the N TMR current sensors.

[0023] The TMR current sensor array expands the current detection range of a single TMR current sensor. The range switching circuit and the switch switching circuit function as a feedforward loop, enabling rapid response and precise switching between different current ranges. Furthermore, the wide-range current measurement circuit provided by the present disclosure is based on the TMR current sensor array, which features high sensitivity, fast response speed, and is not susceptible to current amplitude and frequency range limitations, as well as the range switching circuit and the switch switching circuit. This circuit not only enables wide-range current detection, but also achieves high precision and high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0025] Figure 1 The diagram schematically shows the curve of the resistance value of a single magnetoresistive element changing with the strength of the external magnetic field;

[0026] Figure 2 The structure diagram of the wide-range current measurement circuit provided in accordance with an embodiment of the present disclosure is schematically shown;

[0027] Figure 3 The schematic diagram of the structure of the range switching circuit provided according to the embodiment of the present disclosure is shown schematically;

[0028] Figure 4 A wide-range current measurement circuit provided according to an embodiment of the present disclosure is schematically shown;

[0029] Figure 5 The following schematically shows a structural diagram of a programmable gain amplifier circuit provided according to an embodiment of the present disclosure;

[0030] Figure 6 Another wide-range current measurement circuit provided according to an embodiment of the present disclosure is schematically shown; and

[0031] Figure 7 The flowchart of the wide-range current measurement method provided in accordance with an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0034] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0035] Current is one of the key state variables that must be monitored during power grid operation. Real-time current monitoring enables real-time monitoring of the grid's operating status, the rational allocation of power resources, and transmission line troubleshooting. Therefore, achieving real-time, accurate, and reliable current detection is crucial to the normal operation of the power grid system.

[0036] A wide variety of currents typically exist in power grid systems, including operating currents in distribution systems, stable currents such as line currents in AC and DC transmission lines, currents in short-circuited transmission lines, non-operating currents such as harmonic currents, corona currents, and lightning currents, and leakage currents from electrical equipment such as lightning arresters. These currents are complex and difficult to measure, with a wide range of amplitudes and frequencies. For example, their amplitudes range from low uA to high mA, and their operating frequencies extend from DC to MHz.

[0037] Therefore, to achieve comprehensive and comprehensive detection of all currents in the power grid system, various current sensor modules with different principles and functions exist in the power grid system. Among them, magnetoresistive current sensors based on various magnetoresistive effects, such as giant magnetoresistive effect (GMR) or tunnel magnetoresistive effect (TMR), are commonly used to monitor weak currents with amplitudes in the mA or even uA range due to their high sensitivity, low nonlinearity, and accurate detection of weak magnetic fields.

[0038] The basic working principle of magnetoresistive current sensor is that the resistance value of magnetoresistive element changes linearly with the change of external magnetic field. The resistance value of a single magnetoresistive element changes with the strength of external magnetic field as shown in the following figure: Figure 1As shown in the figure, the horizontal axis represents the magnetic field strength of the external magnetic field, and the vertical axis represents the resistance value of the magnetoresistive element of the magnetoresistive current sensor. Furthermore, since the current flowing through the current conductor to be measured generates a magnetic field that is linearly related to the current, accurate current detection can be achieved by properly arranging the relative position of the magnetoresistive current sensor and the current conductor to be measured.

[0039] Through the working principle of the above magnetoresistive current sensor and Figure 1 The curve showing how the resistance of a single magnetoresistive element changes with the strength of the external magnetic field shows that when the weak magnetic field generated by a weak current is linearly correlated with the resistance of the magnetoresistive element, a single magnetoresistive current sensor can achieve high-sensitivity and high-precision detection of weak currents. However, as the measured current continues to increase, the magnetic field strength generated by the current also increases. When the magnetic field strength increases to a certain range, the curve showing how the resistance of the magnetoresistive element changes with the strength of the external magnetic field enters a nonlinear region or even a saturation region. The nonlinear and saturation regions indicate that, at a higher range of measured currents, the magnetic field strength generated by the measured current experienced by a single magnetoresistive current sensor exceeds its linear operating range, resulting in a nonlinear response in the resistance of the magnetoresistive element. Therefore, a single magnetoresistive current sensor cannot effectively detect currents over a wide range.

[0040] Related technologies often use a current sensor that connects a Hall sensor and a magnetoresistive current sensor in series to detect currents with a large current amplitude distribution span, that is, a wide range. Among them, the Hall sensor is capable of detecting currents in a large range, and the magnetoresistive current sensor is capable of detecting currents in a small range. The current sensor integrates the current measurement results of the Hall sensor and the magnetoresistive current sensor based on a processing circuit to detect currents in a wide range. However, the current sensors in related technologies have poor performance problems such as low sensitivity, slow response speed, and susceptibility to limitations in the current amplitude range and frequency range. Therefore, the current sensors in related technologies cannot achieve high-precision detection of currents in a wide range.

[0041] In order to at least partially solve the technical problems existing in the related art, an embodiment of the present disclosure provides a wide-range current measurement circuit, which can be applied to the field of power electronics technology.

[0042] Figure 2 The schematic diagram shows the structure of a wide-range current measurement circuit provided according to an embodiment of the present disclosure.

[0043] like Figure 2As shown, the wide-range current measurement circuit 100 provided in an embodiment of the present disclosure includes a TMR current sensor array 10, a range switching circuit 20, and a switch switching circuit 30. The TMR current sensor array 10 includes N TMR current sensors 11, each of which is used to detect the current of a current conductor to be measured, and each of the N TMR current sensors 11 has a different range. The range switching circuit 20 is used to output N control signals based on the current measurement values ​​of each of the N TMR current sensors 11. The switch switching circuit 30 includes N switches 31, which are used to control the conduction and disconnection of the N switches 31 based on the N control signals to control the selection of each of the N TMR current sensors 11, where N is a positive integer.

[0044] Compared with the related art, the wide-range current measurement circuit 100 provided by the present disclosure has the following beneficial effects:

[0045] The wide-range current measurement circuit 100 provided herein utilizes a TMR current sensor array 10. Each of the N TMR current sensors 11 has a different measurement range, enabling detection across a wide current range. A range switching circuit 20 outputs N control signals based on the current measurement values ​​of each of the N TMR current sensors 11. A switch switching circuit 30 controls the on and off states of N switches 31 based on the N control signals, thereby controlling the gating of each of the N TMR current sensors 11.

[0046] Thus, the TMR current sensor array 10 provided in the embodiment of the present disclosure broadens the current detection range of a single TMR current sensor. The range switching circuit 20 and the switch switching circuit 30, acting as a feedforward loop, can achieve rapid response and precise switching for detecting different current ranges. Furthermore, the TMR current sensor has advantages such as high measurement sensitivity, fast response speed to current, and being less susceptible to limitations in current amplitude range and frequency range. Therefore, the wide-range current measurement circuit 100 provided in the present disclosure can not only detect currents over a wide range, but also achieve high-precision and high-sensitivity current detection. Furthermore, the wide-range current measurement circuit 100 provided in the present disclosure is compact, facilitating subsequent integrated design with a single-chip microcomputer, and has a wider range of application scenarios, capable of meeting various complex application requirements.

[0047] According to an embodiment of the present disclosure, the measuring range of each of the N TMR current sensors 11 is determined based on the distance between each of the N TMR current sensors 11 and the current conductor to be measured. As a result, the distances between each of the N TMR current sensors 11 and the current conductor to be measured vary, resulting in different spatial orientations of the N TMR current sensors 11 relative to the current conductor to be measured. TMR current sensors closer to the current conductor to be measured have a smaller current measurement range and higher sensitivity, while TMR current sensors farther from the current conductor to be measured have a larger current measurement range and lower sensitivity. Therefore, the TMR current sensor array 10 comprising N TMR current sensors 11 is capable of detecting currents over a wide range.

[0048] Figure 3 The schematic diagram of the structure of the range switching circuit 20 provided according to the embodiment of the present disclosure is shown schematically. Figure 3 As shown, the range switching circuit 20 includes N-1 comparators 21, wherein the positive input of the i-th comparator is connected to the i-th TMR current sensor, and the negative input of the i-th comparator is used to receive the i-th reference voltage, where i is a positive integer and i≤N-1. The i-th reference voltage refers to the saturation field output voltage of the i-th comparator. It should be noted that the N-th TMR current sensor 11 is not connected to the comparator. Therefore, by collecting the output signal of the i-th TMR current sensor and sending it to the i-th comparator, the operating status of the i-th TMR current sensor can be determined, and it can be determined whether the current of the current conductor to be measured exceeds the current detection operating range of the i-th TMR current sensor when the current varies within a wide range.

[0049] like Figure 3 As shown, the range switching circuit 20 may further include a decoder 22, which outputs N control signals based on the output results of the N-1 comparators 21. The decoder 22 includes N-1 input terminals and N output terminals. The i-th input terminal of the decoder 22 is connected to the output terminal of the i-th comparator, and the j-th output terminal of the decoder 22 is connected to the j-th switch of the switching circuit 30, where j is a positive integer and j ≤ N. Thus, the output results of the N-1 comparators 21 are input to the decoder 22, and the N control signals output by the decoder 22 are used to control the conduction and disconnection of the N switches 31 in the switching circuit 30.

[0050] According to an embodiment of the present disclosure, the jth switch of the switching circuit 30 is connected to the jth TMR current sensor of the TMR current sensor array 10. Thus, the N control signals output by the decoder 22 control the on and off switching of the N switches 31 in the switching circuit, thereby controlling the gating of each of the N TMR current sensors 11. This allows the wide-range current measurement circuit 100 provided by the embodiment of the present disclosure to adaptively switch to the appropriate detection range when the current in the current conductor to be measured varies over a wide range.

[0051] Taking N=3 as an example, the implementation of the wide-range current measurement circuit provided by the present disclosure is exemplarily described.

[0052] Figure 4 A wide range current measurement circuit according to an embodiment of the present disclosure is schematically shown. Figure 4 As shown, the TMR current sensor array 10 includes three TMR current sensors, that is, the TMR current sensor array 10 includes a first TMR current sensor 111 , a second TMR current sensor 112 and a third TMR current sensor 113 .

[0053] The first TMR current sensor 111 is located closer to the current conductor to be measured than the second TMR current sensor 112 and the third TMR current sensor 113. The measurement range of the first TMR current sensor 111 can be in the order of μA to mA, corresponding to small-range current detection. The third TMR current sensor 113 is located further away from the current conductor to be measured than the first TMR current sensor 111 and the second TMR current sensor 112. The measurement range of the third TMR current sensor 113 can be in the order of A to kA, corresponding to large-range current detection. The second TMR current sensor 112 is located between the first TMR current sensor 111 and the third TMR current sensor 113. The measurement range of the second TMR current sensor 112 can be in the order of mA to A, corresponding to medium-range current detection.

[0054] The number of comparators can be two, that is, the range switching circuit 20 can include a first comparator 211 and a second comparator 212. The positive input terminal of the first comparator 211 is connected to the first TMR current sensor 111, and the negative input terminal of the first comparator 211 is used to receive the first reference voltage V ref1 The positive input terminal of the second comparator 212 is connected to the second TMR current sensor 112, and the negative input terminal of the second comparator 212 is used to receive the second reference voltage V ref2 The third TMR current sensor 113 is connected neither to the first comparator 211 nor to the second comparator 212 .

[0055] The decoder 22 may output three control signals based on the output results of the first comparator 211 and the second comparator 212. The decoder 22 may include two input terminals and three output terminals, wherein the first input terminal of the decoder 22 is connected to the output terminal of the first comparator 211, and the second input terminal of the decoder 22 is connected to the output terminal of the second comparator 212.

[0056] The switching circuit 30 may include a first switch S1, a second switch S2, and a third switch S3. A first output terminal of the decoder 22 is connected to the first switch S1 in the switching circuit 30, a second output terminal of the decoder 22 is connected to the second switch S2 in the switching circuit 30, and a third output terminal of the decoder 22 is connected to the third switch S3 in the switching circuit 30. The first switch S1 of the switching circuit 30 is connected to the first TMR current sensor 111, the second switch S2 is connected to the second TMR current sensor 112, and the third switch S3 is connected to the third TMR current sensor 113.

[0057] According to an embodiment of the present disclosure, when the outputs of the N-1 comparators 21 of the range switching circuit 20 are all "0", the decoder 22 outputs the first control signal, the first switch S1 of the switch switching circuit 30 is turned on, and the remaining N-1 switches of the switch switching circuit 30 are all turned off. When the outputs of the first i comparators of the range switching circuit 20 are all "1", and the outputs of the remaining N-1-i comparators of the range switching circuit 20 are all "0", the decoder 22 outputs the i+1th control signal, the i+1th switch of the switch switching circuit 30 is turned on, and the remaining N-1 switches of the switch switching circuit 30 are all turned off. When the outputs of the N-1 comparators 21 of the range switching circuit 20 are all "1", the decoder 22 outputs the Nth control signal, the Nth switch 31 of the switch switching circuit 30 is turned on, and the remaining N-1 switches of the switch switching circuit 30 are all turned off.

[0058] Taking N=3 as an example, the implementation of the wide-range current measurement circuit provided by the present disclosure is exemplified. The working state of a wide-range current measurement circuit provided by the embodiment of the present disclosure is shown in Table 1:

[0059] Table 1

[0060] Comparator output result Switch status Wide range current measurement circuit working range "00” <![CDATA[S1 is turned on, S2 and S3 are turned off]]> Small range "10” <![CDATA[S2 is turned on, S1 and S3 are turned off]]> mid-range "11” <![CDATA[S3 is turned on, S1 and S2 are turned off]]> Large range

[0061] As shown in Table 1, when the output of first comparator 211 of range switching circuit 20 is "0" and the output of second comparator 212 is "0," i.e., when the comparator output is "00," the current in the current conductor to be measured is low, and the wide-range current measurement circuit operates within the narrow range. Decoder 22 outputs a first control signal, turning on first switch S1 of switch switching circuit 30 and turning off second switch S2 and third switch S3.

[0062] When the output of first comparator 211 of range switching circuit 20 is "1" and the output of second comparator 212 is "0," i.e., the comparator output is "10," the current in the current conductor to be measured increases to the mid-range range, and the wide-range current measurement circuit operates in the mid-range range. Decoder 22 outputs a second control signal, turning on second switch S2 of switch switching circuit 30 and turning off first switch S1 and third switch S3.

[0063] When the output of first comparator 211 of range switching circuit 20 is "1" and the output of second comparator 212 is "1," i.e., the comparator output is "11," the current in the current conductor to be measured further increases to the wide-range range, and the wide-range current measurement circuit operates within the wide-range range. Decoder 22 outputs a third control signal, turning on third switch S3 of switch switching circuit 30 and turning off first switch S1 and second switch S2.

[0064] Taking N=4 as an example, the embodiment of the wide-range current measurement circuit provided by the present disclosure is exemplified. The TMR current sensor array 10 in the wide-range current measurement circuit 100 may include four TMR current sensors, the range switching circuit 20 may include three comparators, and the switch switching circuit 30 may include four switches.

[0065] When the outputs of the three comparators of the range switching circuit 20 are all "0", that is, when the outputs of the first comparator 211, the second comparator 212 and the third comparator are all "0", the decoder 22 outputs the first control signal, the first switch S1 of the switch switching circuit 30 is turned on, and the second switch S2, the third switch S3 and the fourth switch are all turned off.

[0066] When the output of the first comparator 211 of the range switching circuit 20 is "1" and the outputs of the second comparator 212 and the third comparator are both "0", the decoder 22 outputs a second control signal, the second switch S2 of the switch switching circuit 30 is turned on, and the first switch S1, the third switch S3 and the fourth switch are all turned off.

[0067] When the outputs of the first comparator 211 and the second comparator 212 of the range switching circuit 20 are both "1" and the output of the third comparator is "0", the decoder 22 outputs a third control signal, the third switch S3 of the switch switching circuit 30 is turned on, and the first switch S1, the second switch S2 and the fourth switch are all turned off.

[0068] When the outputs of the three comparators of the range switching circuit 20 are all "1", that is, when the outputs of the first comparator 211, the second comparator 212 and the third comparator are all "1", the decoder 22 outputs the fourth control signal, the fourth switch of the switch switching circuit 30 is turned on, and the first switch S1, the second switch S2 and the third switch S3 are all disconnected.

[0069] Figure 5 Schematically shows a structural diagram of a programmable gain amplifier circuit 40 provided according to an embodiment of the present disclosure. Figure 5 As shown, the wide-range current measurement circuit may include, in addition to the TMR current sensor array 10, the range switching circuit 20, and the switch switching circuit 30, a programmable gain amplifier circuit 40. The programmable gain amplifier circuit 40 is connected to the switch switching circuit 30 and is configured to amplify the current measurement value according to the selection of each of the N TMR current sensors 11.

[0070] According to an embodiment of the present disclosure, a programmable gain amplifier circuit 40 includes N gain switches 41 and N load resistors 42. The N gain switches 41 are used to control the conduction and disconnection of the N load resistors 42. Thus, an appropriate gain is selected based on the output signal of the selected TMR current sensor. This allows the output signal of the wide-range current measurement circuit provided by the embodiment of the present disclosure to maintain a high-precision and high-sensitivity response when the current in the current conductor to be measured is within different measurement ranges.

[0071] According to the embodiment provided by the present disclosure, when the outputs of the N-1 comparators 21 of the range switching circuit 20 are all "0", the decoder 22 outputs the first control signal, the first amplification factor switch SW1 of the programmable gain amplifier circuit 40 is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit 40 are all turned off. When the outputs of the first i comparators of the range switching circuit 20 are all "1" and the outputs of the remaining N-1-i comparators of the range switching circuit 20 are all "0", the decoder 22 outputs the i+1th control signal, the i+1th amplification factor switch of the programmable gain amplifier circuit 40 is turned on, and the remaining N-1 switches of the programmable gain amplifier circuit 40 are all turned off. When the outputs of the N-1 comparators 21 of the range switching circuit 20 are all "1", the decoder 22 outputs the Nth control signal, the decoder 22 outputs the i+1th control signal, the Nth amplification factor switch 41 of the programmable gain amplifier circuit 40 is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit 40 are all turned off.

[0072] Taking N=3 as an example, the implementation of the wide-range current measurement circuit provided by the present disclosure is exemplarily described.

[0073] Figure 6 Another wide-range current measurement circuit provided according to an embodiment of the present disclosure is schematically shown. Figure 6 As shown, the programmable gain amplifier circuit 40 may include a first amplification switch SW1, a second amplification switch SW2, a third amplification switch SW3, a first load resistor R1, a second load resistor R2, a third load resistor R3, a first resistor R a and the second resistor R b .

[0074] When decoder 22 outputs the first control signal, the first amplification factor switch SW1 of programmable gain amplifier circuit 40 is turned on, while the second amplification factor switch SW2 and the third amplification factor switch SW3 are turned off. The first load resistor R1 is turned on, while the second load resistor R2 and the third load resistor R3 are turned off.

[0075] When decoder 22 outputs the second control signal, the second gain switch SW2 of programmable gain amplifier circuit 40 is turned on, while the first and third gain switches SW1 and SW3 are turned off. The first and second load resistors R1 and R2 are turned on, while the third load resistor R3 is turned off.

[0076] When the decoder 22 outputs the third control signal, the third gain switch SW3 of the programmable gain amplifier circuit 40 is turned on, the first gain switch SW1 and the second gain switch SW2 are turned off, and the first load resistor R1, the second load resistor R2, and the third load resistor R3 are all turned on.

[0077] Figure 7 The flowchart of the wide-range current measurement method provided in accordance with an embodiment of the present disclosure is schematically shown. Figure 7 As shown, the wide-range current measurement method 700 of this embodiment includes operations S710 to S730.

[0078] In operation S710 , a current of a current conductor to be measured is detected by a plurality of TMR current sensors to obtain respective current measurement values ​​of the plurality of TMR current sensors, wherein the plurality of TMR current sensors have different measurement ranges.

[0079] In operation S720 , a plurality of control signals are outputted based on the current measurement values ​​of the respective TMR current sensors through the range switching circuit.

[0080] In operation S730 , the switch switching circuit controls the on and off of the plurality of switches based on the plurality of control signals to control the gating of each of the plurality of TMR current sensors.

[0081] It should be noted that, unless it is explicitly stated that there is a sequence of execution between different operations shown in the flowchart in the embodiments of the present disclosure, or there is a sequence of execution between different operations in technical implementation, otherwise, the execution order between multiple operations may not be prioritized, and multiple operations may also be executed simultaneously.

[0082] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways, even if such combinations and / or couplings are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or couplings are intended to fall within the scope of this disclosure.

[0083] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A wide-range current measurement circuit, comprising: A TMR current sensor array, wherein the TMR current sensor array includes N TMR current sensors, and each of the N TMR current sensors is used to detect the current of the current conductor to be measured; When N is 3, the N TMR current sensors include a first TMR current sensor, a second TMR current sensor, and a third TMR current sensor; the first TMR current sensor is closer to the current conductor to be measured than the second TMR current sensor and the third TMR current sensor, and the measuring range of the first TMR current sensor is in the order of μA to mA; the third TMR current sensor is farther away from the current conductor to be measured than the first TMR current sensor and the second TMR current sensor, and the measuring range of the third TMR current sensor is in the order of A to kA; the second TMR current sensor is located between the first TMR current sensor and the third TMR current sensor, and the measuring range of the second TMR current sensor is in the order of mA to A. The measuring range of each of the N TMR current sensors is determined based on the distance between each of the N TMR current sensors and the current conductor to be measured; a range switching circuit, the range switching circuit being configured to output N control signals according to respective current measurement values ​​of the N TMR current sensors; as well as a switch switching circuit, the switch switching circuit comprising N switches, the switch switching circuit being configured to control the on and off states of the N switches according to the N control signals, so as to control the gating of each of the N TMR current sensors, wherein N is a positive integer; a programmable gain amplifier circuit, connected to the switch circuit, for amplifying the current measurement value according to the respective gating of the N TMR current sensors; The programmable gain amplifier circuit includes N amplification switches and N load resistors, and the N amplification switches are used to control the conduction and disconnection of the N load resistors; Wherein, when the outputs of N-1 comparators of the range switching circuit are all "0", the decoder of the range switching circuit outputs a first control signal, the first amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit are all turned off; When the outputs of the first i comparators of the range switching circuit are all “1” and the outputs of the remaining N-1-i comparators of the range switching circuit are all “0”, the decoder outputs the i+1th control signal, the i+1th amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 switches of the programmable gain amplifier circuit are all turned off, where i is a positive integer and i≤N-1; When the outputs of the N-1 comparators of the range switching circuit are all "1", the decoder outputs the Nth control signal, the decoder outputs the i+1th control signal, the Nth amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit are all turned off.

2. The wide-range current measurement circuit according to claim 1, wherein: The range switching circuit includes N-1 comparators; The positive input terminal of the i-th comparator is connected to the i-th TMR current sensor, and the negative input terminal of the i-th comparator is used to receive the i-th reference voltage.

3. The wide-range current measurement circuit according to claim 2, wherein: The range switching circuit also includes a decoder; the decoder outputs the N control signals based on the output results of the N-1 comparators, the decoder includes N-1 input terminals and N output terminals, the i-th input terminal of the decoder is connected to the output terminal of the i-th comparator, and the j-th output terminal of the decoder is connected to the j-th switch of the switch switching circuit, wherein j is a positive integer and j≤N.

4. The wide-range current measurement circuit according to claim 3, wherein: The j-th switch of the switch switching circuit is connected to the j-th TMR current sensor of the TMR current sensor array.

5. The wide-range current measurement circuit according to claim 4, wherein: When the outputs of the N-1 comparators of the range switching circuit are all "0", the decoder outputs a first control signal, the first switch of the switch switching circuit is turned on, and the remaining N-1 switches of the switch switching circuit are turned off; When the outputs of the first i comparators of the range switching circuit are all "1" and the outputs of the remaining N-1-i comparators of the range switching circuit are all "0", the decoder outputs the i+1th control signal, the i+1th switch of the switch switching circuit is turned on, and the remaining N-1 switches of the switch switching circuit are all turned off; When the outputs of the N-1 comparators of the range switching circuit are all "1", the decoder outputs the Nth control signal, the Nth switch of the switch switching circuit is turned on, and the remaining N-1 switches of the switch switching circuit are turned off.

6. A wide-range current measurement method, comprising: detecting the current of the current conductor to be measured by using a plurality of TMR current sensors to obtain current measurement values ​​of each of the plurality of TMR current sensors; In the case where there are N TMR current sensors, and N is 3, the N TMR current sensors include a first TMR current sensor, a second TMR current sensor, and a third TMR current sensor; the first TMR current sensor is closer to the current conductor to be measured than the second TMR current sensor and the third TMR current sensor, and the measuring range of the first TMR current sensor is in the order of μA to mA; the third TMR current sensor is farther away from the current conductor to be measured than the first TMR current sensor and the second TMR current sensor, and the measuring range of the third TMR current sensor is in the order of A to kA; the second TMR current sensor is located between the first TMR current sensor and the third TMR current sensor, and the measuring range of the second TMR current sensor is in the order of mA to A, and the measuring range of each of the N TMR current sensors is determined based on the distance between each of the N TMR current sensors and the current conductor to be measured; outputting a plurality of control signals based on the current measurement values ​​of the respective TMR current sensors through a range switching circuit; as well as Controlling the on and off of the plurality of switches based on the plurality of control signals through a switch switching circuit to control the gating of each of the plurality of TMR current sensors; amplifying the current measurement value by a programmable gain amplifier circuit according to the selection of each of the N TMR current sensors, wherein the programmable gain amplifier circuit includes N amplification switches and N load resistors, and the N load resistors are controlled to be turned on and off by the N amplification switches; Wherein, when the outputs of N-1 comparators of the range switching circuit are all "0", the decoder of the range switching circuit outputs a first control signal, the first amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit are all turned off; When the outputs of the first i comparators of the range switching circuit are all “1” and the outputs of the remaining N-1-i comparators of the range switching circuit are all “0”, the decoder outputs the i+1th control signal, the i+1th amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 switches of the programmable gain amplifier circuit are all turned off, where i is a positive integer and i≤N-1; When the outputs of the N-1 comparators of the range switching circuit are all "1", the decoder outputs the Nth control signal, the decoder outputs the i+1th control signal, the Nth amplification factor switch of the programmable gain amplifier circuit is turned on, and the remaining N-1 amplification factor switches of the programmable gain amplifier circuit are all turned off.

7. The method according to claim 6, wherein: The range switching circuit includes N-1 comparators; The positive input terminal of the i-th comparator is connected to the i-th TMR current sensor, and the negative input terminal of the i-th comparator is used to receive the i-th reference voltage, wherein i is a positive integer and i≤N-1; The range switching circuit further includes a decoder; the decoder outputs N control signals based on the output results of the N-1 comparators, the decoder includes N-1 input terminals and N output terminals, the i-th input terminal of the decoder is connected to the output terminal of the i-th comparator, and the j-th output terminal of the decoder is connected to the j-th switch of the switch switching circuit, wherein j is a positive integer and j≤N; The j-th switch of the switch switching circuit is connected to the j-th TMR current sensor.

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