WO2020006952A1 - Large-range self-energized current sensing apparatus based on anisotropic magnetoresistive effect - Google Patents

Abstract

A large-range self-energized current sensing apparatus (100) based on an anisotropic magnetoresistive effect, the apparatus comprising: a linear magnetic sensor (110), the linear magnetic sensor (110) being composed of an anisotropic magnetoresistive sensor chip, and an output voltage of the linear magnetic sensor (110) being linear with a measured magnetic field; a resonant magnetic field energy collection apparatus (120) for collecting magnetic field energy based on the principle of electromagnetic induction; and an energy management circuit (130) for providing maximum power chasing, boosting, and buck functions, and providing multiple output levels to realize the collection of power-frequency magnetic field energy in the surrounding space and convert the power-frequency magnetic field energy into electric energy for use by the current sensing apparatus (100), wherein the linear magnetic sensor (110), the resonant magnetic field energy collection apparatus (120), and the energy management circuit (130) are integrally disposed. Real-time monitoring of a current can be realized in a self-energized manner around a transmission line, thereby realizing full-scale and long-term reliable monitoring of a grid current with advantages, such as high integration, low costs, a large range, strong robustness and flexible configurations.

Description

Large-range self-powered current sensing device based on anisotropic magnetoresistance effect

Cross-reference to related applications

This application claims the priority of China Patent Application No. “201810719147.4”, filed on July 03, 2018, with the invention name “Large range self-powered current sensing device based on anisotropic magnetoresistance effect”.

Technical field

The invention belongs to the field of novel sensing technology, and particularly relates to a large-range self-powered current sensing device based on anisotropic magnetoresistance effect.

Background technique

With the rise of the Internet of Things concept and people's increasing attention to related technologies, new high-performance wireless self-powered sensor networks have gradually become a research hotspot. Especially in the field of smart grid research, with the introduction of related technologies such as wireless sensor networks, big data, and machine learning, power dispatching has been greatly developed with the support of more real-time monitoring data. However, in the current smart grid sensor network, there are still many key technical issues that need to be solved urgently, for example, the current measurement problem of the power transmission and distribution network and the wireless smart sensor outdoor energy supply problem.

On-line measurement of the current of the transmission and distribution network is the most direct and effective method for estimating network losses and monitoring line loads. As for the current measurement of transmission and distribution networks, currently it is mainly concentrated in converter stations, substations and other places, and there is no good solution for distributed current monitoring of transmission and distribution lines that are widely distributed up to hundreds of kilometers. This is mainly due to the lack of advanced current sensing technology that is miniature, reliable, cheap, and long-range. Currently in power systems, the mainstream current sensing device is a current transformer. The current transformer has the disadvantages of large volume, difficult installation and configuration, high price and easy damage under inrush current. Current transformers are difficult to hang on the network for a long time under the harsh outdoor conditions, and the power transmitted in the power transmission and distribution network is closely related to national production, and daily power outage maintenance is almost impossible. Based on this situation, researchers have proposed many solutions. Among them, the introduction of magnetoresistive chips has provided effective solutions to this problem. First, the working principle of a current sensor based on a magnetoresistive chip is: by measuring the magnetic field generated around the wire, the current in the wire is obtained by inversion, so the chip can be flexibly configured from a long distance; second, the use of a magnetoresistive chip does not require an iron core, The magnetic ring and multi-turn coil greatly reduce the cost of the sensor; again, compared with other magnetic field measurement chips (Hall elements), the magnetoresistive chip has the advantages of good temperature stability and high sensitivity; finally, because the manufacture of the magnetoresistive chip is based on Micro-processing technology, the integration of current sensors based on magnetoresistive chips can be greatly improved. At present, magnetoresistive chips are mainly used in automobiles, machinery, aerospace and data storage, and have not been widely used in smart grids. Compared with other application scenarios, the transmission and distribution current in the smart grid can reach tens of kA. Therefore, compared with the sensitivity valued by other application scenarios, in the smart grid application scenario, linear range is a more important indicator of the magnetoresistive chip. Large-scale magnetoresistive chips have not been widely developed, and the field is still blank.

Summary of the invention

This application is based on the inventor's knowledge and discovery of the following issues:

Wireless smart sensor outdoor energy supply is a major problem that has long plagued the widespread application of wireless networks. At present, indoor wireless networks mainly rely on power lines to provide energy, but outdoor wireless networks cannot be connected to power. In the power system, there is abundant and stable power frequency magnetic field energy around the transmission line. The power frequency magnetic field energy is the most potential energy source for the sensor network. At present, the most popular outdoor energy supply method for sensor networks is to use current mutual inductor coils for energy supply. However, as mentioned earlier, current mutual inductor coils have many disadvantages, so people are also actively exploring new energy supply methods. The electromagnetic energy-based resonance energy harvesting device proposes a novel and effective solution to this problem. First, the electromagnetic induction-based resonant energy harvesting device has a high degree of integration and can be flexibly configured. Its minimum volume is <1 cm ³ and there is no need to configure a magnetic ring around the wire. Second, the electromagnetic induction-based resonant energy harvesting device is The existence of the electromagnetic coupling effect has the characteristics of high power density in the resonance state; again, the resonant energy harvesting device based on electromagnetic resonance resonates at the power frequency condition and has a very strong immunity to lightning current shocks at kHz; Finally, the frequency response of the resonant energy harvesting device based on electromagnetic induction is non-linear, so this type of device has a wide frequency band and has strong immunity to frequency fluctuations in the power grid. However, the electromagnetic induction-based resonant energy harvesting device has the characteristics of low output voltage. In order to ensure that the output AC power is efficiently converted into DC power, a specially designed energy management circuit is required at the back end.

The present invention aims to solve at least one of the technical problems in the related technology to a certain extent.

For this reason, the object of the present invention is to propose a large-range self-powered current sensing device based on anisotropic magnetoresistance effects. The device has the advantages of high integration, low cost, large range, strong robustness, and flexible configuration. .

In order to achieve the above object, an embodiment of one aspect of the present invention proposes a large-range self-powered current sensing device based on anisotropic magnetoresistance effect, including: a linear magnetic sensor, the linear magnetic sensor is transmitted by anisotropic magnetoresistance It consists of a sensor chip, and the output voltage of the linear magnetic sensor has a linear relationship with the measured magnetic field; a resonant magnetic field energy acquisition device is used to collect magnetic field energy based on the principle of electromagnetic induction; an energy management circuit is used to provide the maximum power chase function Voltage function and step-down function, and provide multiple output levels to collect power frequency magnetic field energy in the surrounding space and convert it into electrical energy for use by current sensing devices, wherein the linear magnetic sensor and the resonant magnetic field energy collection The device is integrated with the energy management circuit.

The large-range self-powered current sensing device based on the anisotropic magnetoresistance effect in the embodiment of the present invention integrates a linear magnetic field sensor, a resonant magnetic field energy acquisition device and an energy management circuit based on the principle of electromagnetic induction, and can self-power around a transmission line. It can realize real-time current monitoring, realize comprehensive and long-term reliable monitoring of grid current, and can adapt to the needs of current sensing devices for new-generation smart grids. It has high integration, low cost, large range, strong robustness, and Flexible configuration and other advantages.

In addition, the large-range self-powered current sensing device based on the anisotropic magnetoresistance effect according to the above embodiments of the present invention may also have the following additional technical features:

Further, in an embodiment of the present invention, the resonant magnetic field energy harvesting device includes: a rotating permanent magnet, the rotating permanent magnet is magnetized in a horizontal direction; a fixed permanent magnet, and an offset generated by the fixed permanent magnet. The magnetic field constrains the rotating permanent magnet to a balanced position along the magnetizing direction of the rotating permanent magnet, wherein the driving magnetic field generated by the AC wire is perpendicular to the rotating magnetization direction and the axial direction of the rotating permanent magnet; The rotating permanent magnet is arranged to drive the rotating permanent magnet to oscillate near the equilibrium position and induce electric energy in the surrounding coil when an alternating current magnetic field generated by a current-carrying wire is in operation.

Further, in an embodiment of the present invention, the energy management circuit includes a voltage doubler rectification circuit and an energy management chip, wherein the energy management chip includes a maximum power chase module, a boost module, and a buck module.

Further, in an embodiment of the present invention, it further includes: a connection interface for connecting a long-term energy storage unit, a short-term energy storage unit, and a system load represented by a sensor chip, wherein the short-term energy storage unit meets The temporary high-power demand of the current sensing device, the long-term energy storage unit meets the power demand of the current sensing device when the surrounding magnetic field energy supply is lost, and the system load is the current sensing device. The main load.

Further, in an embodiment of the present invention, the energy management circuit is further configured to access a low input voltage, and boost and output the low input voltage to make the energy management circuit achieve a maximum Power chase, dynamically load match the resonant magnetic field energy harvesting device, so that the resonant magnetic field energy harvesting device maintains a high power output state.

Further, in an embodiment of the present invention, a range of the anisotropic magnetoresistive sensor chip satisfies a preset condition.

Further, in an embodiment of the present invention, the anisotropic magnetoresistive sensor chip has extremely strong shape anisotropy and exchanges a bias magnetic field.

Further, in one embodiment of the present invention, the measurement of thousands of amperes of current is realized in a limited space with a volume of less than 2 cm ³ .

Additional aspects and advantages of the present invention will be given in part in the following description, part of which will become apparent from the following description, or be learned through the practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

1 is a schematic structural diagram of a large-range self-powered current sensing device based on an anisotropic magnetoresistance effect according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a nonlinear resonance magnetic field energy collection device based on an electromagnetic induction principle according to an embodiment of the present invention; FIG.

3 is a schematic block diagram of an energy management circuit according to an embodiment of the present invention;

4 is a schematic diagram of a magnetoresistive bar in an anisotropic magnetoresistive chip according to an embodiment of the present invention.

Reference sign description:

Large-scale self-powered current sensing device 100 based on anisotropic magnetoresistance effect, linear magnetic sensor 110, resonant magnetic field energy harvesting device 120, energy management circuit 130, rotatable permanent magnet 1, shaft 2, surrounding coil 3, fixed Frame 4, fixed permanent magnet 5, bearing 6, bearing fixture 7, DC bias magnetic field 8, AC magnetic field generated by current-carrying wire 9, voltage doubling rectifier circuit 10, maximum power chase module 11, boost module 12, step-down module 13. Short-term energy storage unit 14, system load 15, long-term energy storage unit 16, aluminum 17, anisotropic magnetoresistive strip 18, current direction 19, magnetization direction 20, angle 21 between magnetization direction and current direction, power frequency magnetic field Energy 22, permanent magnet rotating machine energy 23, electrical energy in the coil 24, long-term energy storage unit 25, other system loads 26, and short-term energy storage unit 27.

detailed description

Hereinafter, embodiments of the present invention will be described in detail. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

The following describes a large-range self-powered current sensing device based on anisotropic magnetoresistance effect according to an embodiment of the present invention with reference to the drawings.

FIG. 1 is a schematic structural diagram of a large-range self-powered current sensing device based on an anisotropic magnetoresistance effect according to an embodiment of the present invention.

As shown in FIG. 1, the large-range self-powered current sensing device 100 based on the anisotropic magnetoresistance effect includes a linear magnetic sensor 110, a resonant magnetic field energy collection device 120, and an energy management circuit 130.

The linear magnetic sensor 110 is composed of an anisotropic magnetoresistive sensor chip, and the output voltage of the linear magnetic sensor has a linear relationship with the measured magnetic field. The resonant magnetic field energy collection device 120 is configured to collect magnetic field energy based on the principle of electromagnetic induction. The energy management circuit 130 is used to provide a maximum power chase function, a boost function, and a buck function, and provide multiple output levels to realize the collection of power frequency magnetic field energy in the surrounding space and conversion into electrical energy for use by the current sensing device. Among them, Linear magnetic sensors, resonant magnetic field energy harvesting devices and energy management circuits are integrated. The device 100 according to the embodiment of the present invention can realize real-time current monitoring in a self-powered manner around a power transmission line, realize comprehensive and long-term reliable monitoring of grid current, and has high integration, low cost, large range, strong robustness, and configuration. Flexibility and other advantages.

It can be understood that the device 100 according to the embodiment of the present invention includes a resonance-type magnetic field energy harvesting device based on the principle of electromagnetic induction, an energy management circuit having a maximum power chasing function, a boosting function, a step-down function, and providing multiple output levels. And large-range magnetic field sensors based on anisotropic magnetoresistance effects. The embodiment of the present invention collects power frequency magnetic field energy in the surrounding space and converts it into electrical energy for use by the current sensing device 100.

Further, in an embodiment of the present invention, the resonant magnetic field energy harvesting device 120 includes: a rotating permanent magnet, a fixed permanent magnet, and a surrounding coil.

Among them, the rotating permanent magnet is magnetized in the horizontal direction. The bias magnetic field generated by the fixed permanent magnet constrains the rotating permanent magnet to an equilibrium position along the magnetizing direction of the rotating permanent magnet, wherein the driving magnetic field generated by the AC wire is perpendicular to the magnetizing direction and axial direction of the rotating permanent magnet. The surrounding coil is arranged around the rotating permanent magnet, so that during operation, the alternating magnetic field generated by the current-carrying wire drives the rotating permanent magnet to swing near the equilibrium position, and induces electric energy in the surrounding coil.

It can be understood that the resonant magnetic field energy harvesting device 120 based on the principle of electromagnetic induction is composed of a rotatable permanent magnet, a fixed permanent magnet, and a surrounding coil. The rotating permanent magnet is magnetized in the horizontal direction (vertical to the axis). The bias magnetic field generated by the fixed permanent magnet constrains the rotating permanent magnet to an equilibrium position along the rotating permanent magnet magnetization direction. The driving magnetic field generated by the AC wire and the rotating permanent magnet are magnetized. The direction and axial direction are perpendicular, and the surrounding coil is arranged around the rotating permanent magnet. During operation, the AC magnetic field generated by the current-carrying wire drives the rotating permanent magnet to swing near the equilibrium position and induces electric energy in the surrounding coil.

Specifically, a structural cross-sectional view of the energy harvesting device 120 is shown in FIG. 2, wherein FIG. 2 (a) is a plan cross-sectional view of the device, and FIG. 2 (b) is a front cross-sectional view of the device, including: a rotatable permanent magnet 1 , Shaft 2, surrounding coil 3, fixed frame 4, fixed permanent magnet 5, bearing 6, bearing fixing member 7.

Among them, the rotatable permanent magnet 1 is magnetized in the x direction, and the shaft 2 passes through the center of the rotatable permanent magnet 1 to form a rotatable part. Both ends of the shaft 2 in the rotatable part are pressed into the inner ring of the bearing 6. The outer ring is fixed on the bearing fixing member 7. The bearing fixing member 7 is fixed in the central through hole of the fixing frame 4 by crimping and bonding. The bearing fixing member 7 can also be processed and formed together with the fixing frame 4. The surrounding coil 3 is wound under the outer step of the fixed frame 4. Two fixed permanent magnets 5 magnetized in the x direction are placed on both sides of the fixed frame 4 along the X axis.

When the energy harvesting device 120 is in operation, the DC bias magnetic field 8 generated by the fixed permanent magnet 5 constrains the magnetization direction of the rotatable permanent magnet along the x-axis. Under the action of the AC magnetic field 9 generated by the current carrying wire, the rotatable permanent magnet 1 Swing around the direction indicated in Figure 2 in the order of ①②③④. The magnetic field lines generated by the rotatable permanent magnet 1 repeatedly cut the surrounding coil 3 when swinging, and output considerable electric power in the surrounding coil 3. Although the electric power far exceeds the electric power generated by other energy harvesting methods, its corresponding voltage is relatively low, and this power is seriously affected by the size of the load. To solve the above problems, an embodiment of the present invention specifically designs an energy management circuit 130. The energy management circuit 130 will be further described below.

Further, in one embodiment of the present invention, the energy management circuit 130 includes a voltage doubler rectifier circuit and an energy management chip, wherein the energy management chip includes a maximum power chase module, a boost module and a buck module.

Further, in an embodiment of the present invention, the energy management circuit 130 is further configured to access a low input voltage, and boost and output the low input voltage to enable the energy management circuit to achieve maximum power chase and dynamically Load matching is performed on the resonant magnetic field energy harvesting device so that the resonant magnetic field energy harvesting device maintains a high power output state.

It can be understood that the energy management circuit 130 can be connected to a low input voltage, and the voltage is boosted and regulated to output. In this process, the energy management circuit 130 can achieve maximum power chase, dynamically load match the energy harvesting device, and help the energy harvesting device maintain a high power output state.

Specifically, as shown in FIG. 3, the energy management circuit 130 includes: a voltage doubler rectification circuit 10, a maximum power chasing module 11, a boost module 12, a step-down module 13, a short-term energy storage unit 14, a system load 15, and a long-term storage Energy unit 16.

The voltage doubling rectifier circuit 10 doubles the input AC voltage and converts it into a DC voltage. The DC voltage is connected to the maximum power chasing module 11. The maximum power chasing module 11 uses a constant current method to find the ideal output power in the current state. The maximum power chase When the module 11 is in operation, the back-end circuit and the voltage doubler rectifier circuit 10 are isolated at intervals. At this time, the energy harvesting device is in an open circuit state. The maximum power chasing module 11 collects the open-circuit DC voltage input at this time, and then restores the back-end. The circuit is normally connected to the voltage doubler rectifier circuit 10, and the input DC voltage is controlled within the range of 70% -90% of the open-circuit DC voltage before the next isolation (the specific ratio is determined according to the curve of the energy harvesting output power with the load), and the voltage is boosted. The module 12 raises the DC voltage adjusted by the maximum power chasing module 11 to an ideal voltage (usually 5V, which can also be adjusted according to the actual situation). In order to meet some other voltage requirements, the step-down module 13 is connected to the boost module After 12, the boosted DC voltage can be reduced to the ideal voltage (usually 3.3V, or according to the actual situation) Whole). Thereafter, the short-term energy storage unit 14, the system load 15, and the long-term energy storage unit 16 are respectively connected after the step-up or step-down module according to their respective voltage requirements.

And in the energy management circuit 130, the system load 15 is mainly an anisotropic magnetoresistive sensor chip. The anisotropic magnetoresistive sensor chip will be further explained below.

Further, in an embodiment of the present invention, the range of the anisotropic magnetoresistive sensor chip satisfies a preset condition.

It can be understood that the linear magnetic sensor 110 is made based on a large-range anisotropic magnetoresistive chip.

Further, in one embodiment of the present invention, the anisotropic magnetoresistive sensor chip has extremely strong shape anisotropy and exchanges a bias magnetic field.

It can be understood that the anisotropic magnetoresistive chip used in the embodiments of the present invention is specially designed to have extremely strong shape anisotropy and exchange bias magnetic fields.

Specifically, as shown in FIG. 4, the magnetoresistive strips of the anisotropic magnetoresistive sensor chip are arranged in a Wheatstone bridge, and the structure of a single magnetoresistive strip is shown in FIG. 3, including: aluminum 17 and anisotropy.磁 磁条 18。 Magnetic resistance strip 18.

Among them, there are two vertical structures (from bottom to top) of the anisotropic magnetoresistive stripe 18: Si / IrMn / NiFe / IrMn / Ta and Si / IrMn / NiFe / Ta. Si is used as the base material, and IrMn provides exchange. Bias magnetic field, NiFe is the main material of anisotropic magnetoresistance effect, Ta provides surface protection. The anisotropic magnetoresistive stripe 18 is specially made into a long shape. For example, the anisotropic magnetoresistive stripe 18 has a length of up to 1600um, a width of 0.5um, and a length-to-width ratio of up to 3200, which results in anisotropic The strong shape anisotropy of the anisotropic magnetoresistive strip 18. The rate of change of magnetic resistance varies with the angle θ _M 21 between the direction of magnetization 20 and the direction of current 19 (where

Is the change rate of magnetic resistance, MR _max is the maximum change rate of magnetic resistance):

According to the above relationship, when θ _M 21 is in the range of 0-90 °, the magnetic resistance change rate changes linearly. Therefore, the strip is made of aluminum 17 material, covered above the anisotropic magnetoresistive strip 18, and guided by the aluminum 17 material. Current direction 19, so that the angle between the initial current direction 19 and the magnetization direction 20 is 45 °, so that the magnetization direction 20 of the anisotropic magnetoresistive strip 18 is under the effect of the external magnetic field 9 and the angle between the horizontal line is ﹣45 ° ~ + 45 The rate of change of magnetoresistance within the range of rotation changes linearly.

Further, in an embodiment of the present invention, the device 100 according to the embodiment of the present invention further includes: a connection interface. Among them, the connection interface is used to connect the long-term energy storage unit, the short-term energy storage unit, and the system load represented by the sensor chip. Among them, the short-term energy storage unit meets the temporary high-power demand of the current sensing device, and the long-term energy storage unit meets The power demand of the current sensing device when the surrounding magnetic field energy supply is lost, the system load is the main load in the current sensing device.

Further, in one embodiment of the present invention, the measurement of thousands of amperes of current is realized in a limited space with a volume of less than 2 cm ³ .

It can be understood that the device 100 according to the embodiment of the present invention can realize the measurement of the kA current on the basis that the volume is less than 2 cm3.

In summary, as shown in FIG. 1, the device 100 according to the present invention is divided into three parts: an energy harvesting device 120, an energy management circuit 130, and an anisotropic magnetoresistive chip. In the energy harvesting device 120, the power-frequency magnetic field energy 22 generated by the power transmission line is first converted into the mechanical energy 23 of the rotatable permanent magnet 1, which is converted into AC as the magnetic field lines generated by the rotatable permanent magnet 1 cut around the coil 3. Electrical energy 24. The AC power 24 output from the energy harvesting device 120 is connected to the energy management circuit 130. After rectification, voltage regulation and voltage stabilization, it can be output to the long-term energy storage unit 25, short-term energy storage unit 27, and anisotropic magnetoresistive chip, respectively. And other system loads 26. Other system loads may include power consumption modules such as communication modules and temperature measurement modules.

Further, the large-range self-powered current sensing device based on the anisotropic magnetoresistance effect has the following advantages:

(1) Small size, high integration, and flexible configuration methods. Unlike traditional current transformers, the device of the embodiment of the present invention does not require an iron core and a magnetic ring, thereby greatly reducing the device volume and allowing flexible configuration away from the wires.

(2) The measuring range is large, and it can measure the conventional large current in the power grid and even the transient impulse current under abnormal conditions.

(3) Each link is specially designed. Considering the abnormal situation in the power grid, it is robust and can withstand transient shocks in the power grid. It is suitable for long-term outdoor operation. On the one hand, the front end uses an anisotropic magnetoresistive sensor chip. Compared with other types of magnetoresistive chips, such chips have the characteristics of simple structure and are not easy to be damaged under impact. On the other hand, the back-end energy harvesting device is a resonant device, which has strong vibration only under power frequency conditions. Characteristics of frequency shock immunity.

(4) The production is simple and the cost is low. The core components are PCB boards, permanent magnets and enameled wires, all of which are ordinary materials.

(5) The energy harvesting device used in the embodiment of the present invention has the characteristics of high power density and large resonance bandwidth, and is not sensitive to power grid frequency fluctuations.

The large-range self-powered current sensing device based on the anisotropic magnetoresistance effect according to the embodiment of the present invention integrates a linear magnetic field sensor, a resonant magnetic field energy acquisition device based on the principle of electromagnetic induction, and an energy management circuit. Real-time current monitoring is realized by self-powered surroundings, realizing comprehensive and long-term reliable monitoring of the grid current, which can adapt to the current generation of smart grid's demand for current sensing devices, and has high integration, low cost, large range, and strong robustness. Flexibility and configuration methods.

In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, for example, two, three, etc., unless it is specifically and specifically defined otherwise.

In the description of this specification, the description with reference to the terms “one embodiment”, “some embodiments”, “examples”, “specific examples”, or “some examples” and the like means specific features described in conjunction with the embodiments or examples , Structures, materials, or features are included in at least one embodiment or example of the invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without any contradiction, those skilled in the art may combine and combine different embodiments or examples and features of the different embodiments or examples described in this specification.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Those skilled in the art can interpret the above within the scope of the present invention. Embodiments are subject to change, modification, substitution, and modification.

Claims (8)

1. A large-range self-powered current sensing device based on anisotropic magnetoresistance, which includes:

   A linear magnetic sensor composed of an anisotropic magnetoresistive sensor chip, and the output voltage of the linear magnetic sensor has a linear relationship with the measured magnetic field;

   Resonant magnetic field energy harvesting device for collecting magnetic field energy based on the principle of electromagnetic induction; and

   Energy management circuit for providing maximum power chase function, boost function and step-down function, and provide multiple output levels to collect power frequency magnetic field energy in the surrounding space and convert it into electrical energy for use by the current sensing device. Among them, The linear magnetic sensor, the resonant magnetic field energy harvesting device, and the energy management circuit are integrated.
2. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1, wherein the resonant magnetic field energy harvesting device comprises:

   A rotating permanent magnet that is magnetized in a horizontal direction;

   A fixed permanent magnet, the bias magnetic field generated by the fixed permanent magnet constrains the rotating permanent magnet to an equilibrium position along the rotating permanent magnet magnetization direction, wherein a driving magnetic field generated by an AC wire and the rotating permanent magnet magnetization direction and Axial are vertical;

   A surrounding coil, the surrounding coil is arranged around the rotating permanent magnet, so that during operation, the alternating magnetic field generated by the current-carrying wire drives the rotating permanent magnet to swing near the equilibrium position, and is induced in the surrounding coil Electrical energy.
3. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1, wherein the energy management circuit comprises:

   The voltage doubler rectification circuit and the energy management chip, wherein the energy management chip includes a maximum power chase module, a boost module and a buck module.
4. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1, further comprising:

   A connection interface for connecting a long-term energy storage unit, a short-term energy storage unit, and a system load represented by a sensor chip, wherein the short-term energy storage unit meets a temporary high-power requirement of the current sensing device, and the long-term The energy storage unit meets the power demand of the current sensing device when it loses the energy supply of the surrounding magnetic field, and the system load is the main load in the current sensing device.
5. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1, wherein the energy management circuit is further configured to access a low input voltage and raise the low input voltage. The voltage is output after voltage stabilization, so that the energy management circuit achieves maximum power chase, and dynamically performs load matching on the resonant magnetic field energy harvesting device, so that the resonant magnetic field energy harvesting device maintains a high power output state.
6. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1, wherein the range of the anisotropic magnetoresistive sensor chip satisfies a preset condition.
7. The large-range self-powered current sensing device based on anisotropic magnetoresistance according to claim 1 or 6, wherein the anisotropic magnetoresistive sensor chip has extremely strong shape anisotropy and exchange bias. Placing a magnetic field.
8. The large-range self-powered current sensing device based on the anisotropic magnetoresistance effect according to any one of claims 1 to 7, characterized in that the volume is less than 2 ^cm3 to realize measurement of thousands of amperes of current.

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