阅读说明：本技术 基于磁电效应的磁成像阵列传感器 (Magnetic imaging array sensor based on magnetoelectric effect ) 是由 鲁丽 焦杰 罗豪甦 狄文宁 梁柱 陈瑞 王宇航 于 2020-12-28 设计创作，主要内容包括：一种基于磁电效应的磁成像阵列传感器,包括：中空壳体状的外屏蔽层；位于外屏蔽层的底部的第一机械支撑层；位于第一机械支撑层的上方的第一导电层；设置于第一导电层的上方,包括以阵列形式排列的多个磁电敏感元的磁电敏感元阵列；位于磁电敏感元阵列的上方的第二导电层；位于第二导电层的上方的第二机械支撑层；以及分别与磁电敏感元对应地设置于第二机械支撑层的上方,将多个磁电敏感元输出的电荷信号转变为电压信号的多个前置电路。该基于磁电效应的磁成像阵列传感器能在线无损检测电池的电流密度分布情况,判断电池有否发生故障,并根据电流密度分布图准确定位电池的故障位置,从而提升电池使用的安全性。(A magnetic imaging array sensor based on magnetoelectric effects, comprising: a hollow shell-like outer shield layer; a first mechanical support layer located at the bottom of the outer shield layer; a first conductive layer located over the first mechanical support layer; a magnetoelectric sensing element array which is arranged above the first conducting layer and comprises a plurality of magnetoelectric sensing elements arranged in an array form; the second conducting layer is positioned above the magnetoelectricity sensitive element array; a second mechanical support layer over the second conductive layer; and the front circuits are respectively arranged above the second mechanical supporting layer corresponding to the magnetoelectric sensitive elements and used for converting charge signals output by the magnetoelectric sensitive elements into voltage signals. The magnetic imaging array sensor based on the magnetoelectric effect can perform online nondestructive detection on the current density distribution condition of the battery, judge whether the battery has a fault or not, and accurately position the fault position of the battery according to the current density distribution diagram, so that the use safety of the battery is improved.)

1. A magnetic imaging array sensor based on magnetoelectric effect is characterized in that,

the method comprises the following steps:

a hollow shell-like outer shield layer;

a first mechanical support layer located at the bottom of the outer shield layer;

a first conductive layer located over the first mechanical support layer;

the magnetoelectric sensitive element array is arranged above the first conducting layer and comprises a plurality of magnetoelectric sensitive elements which are arranged in an array form;

the second conducting layer is positioned above the magnetoelectricity sensitive element array;

a second mechanical support layer over the second conductive layer; and

and the front-end circuits are respectively arranged above the second mechanical supporting layer corresponding to the magnetoelectric sensitive elements and convert charge signals output by the magnetoelectric sensitive elements into voltage signals.

2. A magnetic imaging array sensor based on magnetoelectric effect according to claim 1,

the plurality of magnetoelectric sensitive elements are arranged in rows and columns to form a two-dimensional array.

3. A magnetic imaging array sensor based on magnetoelectric effect according to claim 1 or 2,

the magnetoelectric sensitive element comprises a magnetoelectric complex and magnets arranged at two ends of the magnetoelectric complex;

the magnetoelectric complex is formed by compounding two layers of magnetostrictive materials and a layer of piezoelectric material positioned between the two layers of magnetostrictive materials;

the magnetoelectric sensitive element is arranged above the first conducting layer by taking the laminating direction of the magnetostrictive material and the piezoelectric material as the up-down direction.

4. A magnetoelectric effect-based magnetic imaging array sensor according to any one of claims 1 to 3,

the magnetostrictive material is Terfenol-D or Metglas;

the piezoelectric material is PMNT, BaTiO3 or PZT.

5. A magnetic imaging array sensor based on magnetoelectric effect according to claim 1,

a third conductive layer is disposed between the plurality of front end circuits and the second mechanical support layer.

6. A magnetic imaging array sensor based on magnetoelectric effect according to claim 1,

a first flexible conducting layer is arranged between the first conducting layer and the bottom of the magnetoelectric sensitive element array;

and a second flexible conducting layer is arranged between the second conducting layer and the top of the magnetoelectric sensitive element array.

7. A magnetic imaging array sensor based on magnetoelectric effect according to claim 5 or 6,

the second flexible conducting layer is connected with the input end of the front-end circuit through a signal wire with a shielding shell.

8. A magnetoelectric effect-based magnetic imaging array sensor according to any one of claims 1 to 7,

the first to third conductive layers are made of copper or aluminum;

the first flexible conducting layer and the second flexible conducting layer are made of flexible conducting silver adhesive or a flexible circuit board.

9. A magnetic imaging array sensor based on magnetoelectric effect according to claim 1,

a plurality of mechanical support columns for supporting are also disposed between the first mechanical support layer and the second mechanical support layer.

10. A magnetic imaging array sensor based on magnetoelectric effect according to any one of claims 1 to 9,

the first mechanical support layer, the second mechanical support layer and the mechanical support columns are made of synthetic resin or nylon;

the shielding layer is made of aluminum, copper foil or resin with gold coated on the surface.

Technical Field

The invention belongs to the technical field of magnetic imaging, and particularly relates to a magnetic imaging array sensor based on a magnetoelectric effect.

Background

In recent years, in the face of the severe examination of the shortage of fossil energy and the continuous deterioration of global atmospheric environment, countries in the world are vigorously developing green and environment-friendly high and new technology industries such as new energy automobiles. According to the data counted by the Chinese automobile industry Association, in 2018, under the background of the gliding of the traditional automobiles in production and sales, the new energy automobile still keeps a high-speed growth situation, the production and sales amount is respectively 127 ten thousand and 125.6 ten thousand, and the new energy automobile is 59.9 percent and 61.7 percent higher than that of the new energy automobile in the same period in the last year; the total installed electric quantity of the power battery is about 56.98GWH, which is increased by 56 percent on the same scale. However, the frequent battery fire and automobile spontaneous combustion events expose the potential safety hazard of the new energy automobile, and the development of the new energy automobile is hindered.

Related studies have shown that one of the causes of the battery fire accident is that the current density inside the battery is not uniformly distributed spatially, and this condition is exacerbated as the number of charge and discharge times of the battery increases, eventually resulting in local heat accumulation and fire induced by internal short circuit inside the battery. Therefore, it is urgently required to develop a sensor capable of performing nondestructive detection of the current density distribution inside the battery and giving an accurate judgment of the state of the battery.

The current common battery detection method is to theoretically predict the state of the battery through an equivalent circuit model, and then compare the measured values of electrical parameters such as voltage, current and the like with theoretical values to evaluate the health state of the battery. However, the electrical parameter detection is based on the overall lumped parameters or the limited local lumped parameters, so that the local more detailed current density distribution condition of the battery cannot be obtained, and the local fault of the battery cannot be predicted and identified.

Disclosure of Invention

The problems to be solved by the invention are as follows:

in view of the above problems, an object of the present invention is to provide a magnetic imaging array sensor based on magnetoelectric effect, which can determine whether a battery has a fault and the fault location of the battery by high-resolution real-time online nondestructive detection of the current density distribution condition of the battery.

The technical means for solving the problems are as follows:

in order to solve the above problems, the present invention provides a magnetic imaging array sensor based on magnetoelectric effect, comprising: a hollow shell-like outer shield layer; a first mechanical support layer located at the bottom of the outer shield layer; a first conductive layer located over the first mechanical support layer; the magnetoelectric sensitive element array is arranged above the first conducting layer and comprises a plurality of magnetoelectric sensitive elements which are arranged in an array form; the second conducting layer is positioned above the magnetoelectricity sensitive element array; a second mechanical support layer over the second conductive layer; and the front-end circuits are respectively arranged above the second mechanical supporting layer corresponding to the magnetoelectric sensitive elements and used for converting charge signals output by the magnetoelectric sensitive elements into voltage signals.

According to the invention, the magnetic imaging array sensor has stronger anti-interference capability by arranging the outer shielding layer for forming electrostatic shielding and the conductive layer for shielding electromagnetic interference. By means of the magnetoelectric sensitive element array formed by arranging a plurality of magnetoelectric sensitive elements in an array form and the front-end circuit arranged above each magnetoelectric sensitive element, the current density distribution condition in the battery can be detected on line at low cost in a nondestructive mode.

In the present invention, the plurality of magnetoelectric sensing elements may be arranged in rows and columns to form a two-dimensional array.

In the present invention, the magnetoelectric sensitive element may include a magnetoelectric complex and magnets disposed at two ends of the magnetoelectric complex; the magnetoelectric complex is formed by compounding two layers of magnetostrictive materials and a layer of piezoelectric material positioned between the two layers of magnetostrictive materials; the magnetoelectric sensitive element is arranged above the first conducting layer by taking the laminating direction of the magnetostrictive material and the piezoelectric material as the up-down direction. Therefore, the magnetoelectric sensitive element can be positioned between the two conductive layers and can be prevented from electromagnetic interference.

In the invention, the magnetostrictive material can be Terfenol-D or Metglas; the piezoelectric material is PMNT, BaTiO3 or PZT.

In the present invention, a third conductive layer may be disposed between the plurality of front end circuits and the second mechanical support layer. Electromagnetic interference in the environment can be further effectively shielded by arranging the third conductive layer.

In the invention, a first flexible conductive layer is arranged between the first conductive layer and the bottom of the magnetoelectric sensitive element array; and a second flexible conducting layer is arranged between the second conducting layer and the top of the magnetoelectric sensitive element array. The flexible conducting layer can reduce clamping of the magnetoelectricity sensitive element and improve magnetoelectricity response of the magnetoelectricity sensitive element.

In the present invention, the second flexible conductive layer may be connected to an input terminal of the front end circuit through a signal line with a shielding case. The signal line can input the signal sensed by the magnetoelectric sensitive element into a front-end circuit for signal conditioning.

In the present invention, the first to third conductive layers may be made of copper or aluminum; the first flexible conducting layer and the second flexible conducting layer are made of flexible conducting silver adhesive or a flexible circuit board.

In the present invention, a plurality of mechanical support columns for supporting may be further disposed between the first mechanical support layer and the second mechanical support layer.

In the present invention, the material of the first mechanical support layer, the second mechanical support layer, and the mechanical support columns may be synthetic resin or nylon; the shielding layer is made of aluminum, copper foil or resin with gold coated on the surface.

The invention has the following effects:

the invention has simple structure, small volume and high spatial resolution, can perform online nondestructive detection on the current density distribution condition of the battery, judge whether the battery has a fault, and accurately position the fault position of the battery according to the current density distribution diagram, thereby improving the use safety of the battery.

Drawings

FIG. 1 is a schematic diagram of a structure of a magnetic imaging array sensor based on magnetoelectric effects according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a single magnetoelectric sensing element constituting an array of magnetoelectric sensing elements in the magnetic imaging array sensor shown in fig. 1;

fig. 3 is a battery internal current density distribution diagram obtained by converting the detection values of the magnetic imaging array sensor, (a) shows an example of the internal current density distribution of a healthy battery, and (b) shows an example of the internal current density distribution of a failed battery;

description of the symbols:

100. a magnetic imaging array sensor; 10. an outer shield layer; 21. a first mechanical support layer; 22. a second mechanical support layer; 23. a mechanical support column; 31. a first conductive layer; 32. a second conductive layer; 33. a third conductive layer; 40. a magnetoelectric sensitive element; 41. a magnetostrictive material; 42. a piezoelectric material; 43. a magnet; 50. a front-end circuit; 51. a signal line; 61. a first flexible conductive layer; 62. a second flexible conductive layer.

Detailed Description

The present invention is further described below in conjunction with the following embodiments and the accompanying drawings, it being understood that the drawings and the following embodiments are illustrative of the invention only and are not limiting thereof.

Disclosed herein is a magnetic imaging array sensor based on magnetoelectric effect, which can determine the battery fault location and fault cause by high-resolution real-time online nondestructive detection of the current density distribution condition of a battery. Fig. 1 is a schematic structural diagram of a magnetic imaging array sensor (hereinafter referred to as "magnetic imaging array sensor") 100 based on magnetoelectric effect according to an embodiment of the present invention.

The magnetic imaging array sensor 100 includes an outer shield layer 10, a mechanical support layer, a conductive layer, an array of magnetoelectric sensitive elements, and a plurality of front-end circuits 50. More specifically, as shown in fig. 1, the magnetic imaging array sensor 100 includes an outer shielding layer 10, a first mechanical supporting layer 21 disposed at the bottom of the outer shielding layer 10, a first conductive layer 31 disposed above the first mechanical supporting layer 21, a magnetoelectric sensing element array disposed above the first conductive layer 31, a second conductive layer 32 disposed above the magnetoelectric sensing element array, a second mechanical supporting layer 22 disposed above the second conductive layer 32, and a plurality of front circuits disposed above the second mechanical supporting layer 22.

[ outer Shielding layer ]

The outer shield layer 10 is an outer case of the magnetic imaging array sensor 100, and is formed in a hollow substantially flat rectangular parallelepiped shape. The outer shield layer 10 may be made of aluminum, copper foil, or resin coated with gold, and it protects the internal structure of the magnetic imaging array sensor 100 and forms a good electrostatic shield around the magnetic imaging array sensor 100.

[ mechanical support layer ]

The mechanical support layer, as described above, includes the first mechanical support layer 21 and the second mechanical support layer 22, which are mainly used to support the internal structures of the magnetic imaging array sensor 100. Furthermore, the mechanical support layer may further comprise a pair of mechanical support columns 23 arranged to the first mechanical support layer 21 and the second mechanical support layer 22 for forming a support therebetween. More specifically, in the present embodiment, the first mechanical support layer 21 is stacked on the inner bottom surface of the outer shield layer 10, and the second mechanical support layer 22 is disposed over the magnetoelectric sensitive element array described later by the pair of mechanical support columns 23. The first mechanical support layer 21, the second mechanical support layer 22 and the mechanical support columns 23 may be made of synthetic resin, nylon, or other materials with high mechanical strength, good toughness, heat resistance, light weight, no magnetism and insulation, so as to ensure the mechanical stability and reliability of the magnetic imaging array sensor 100.

[ conductive layer ]

The conductive layers, as described above, include a first conductive layer 31 and a second conductive layer 32, which are mainly used for shielding electromagnetic interference in the environment. Specifically, the first conductive layer 31 is stacked on the upper surface of the first mechanical support layer 21, and the second conductive layer 32 is stacked on the lower surface of the second mechanical support layer 22, so that the magnetoelectric sensitive element array, which will be described later, can be covered in the up-down two directions, and is protected from electromagnetic interference in the environment, thereby improving the imaging resolution of the magnetic imaging array sensor 100. In addition, as shown in fig. 1, in the present embodiment, a third conductive layer 33 is further provided on the upper surface of the second mechanical support layer 22, and the provision of the third conductive layer 33 can further protect signals in the front end circuit from electromagnetic interference in the environment. The conductive layers can be made of metal such as copper, aluminum and the like, and are connected with a power supply negative terminal in a front-end circuit through a lead, and electromagnetic interference signals in the environment are finally led into the power supply negative terminal when entering the conductive layers, so that the signals in the front-end circuit are prevented from being influenced.

[ magnetoelectric sensitive element array ]

An array of magnetoelectric sensitive elements is arranged between the first mechanical support layer 21 and the second mechanical support layer 22, more specifically between the first conductive layer 31 and the second conductive layer 32, and is mainly used for detecting the two-dimensional magnetic field distribution in the space above the cell. In the present embodiment, the magnetoelectric sensing element array may be configured by arranging a plurality of magnetoelectric sensing elements 40 in rows and columns to form a two-dimensional array of n × m, but the present invention is not limited thereto, and the number of rows and columns and the entire number of magnetoelectric sensing elements 40 in the magnetoelectric sensing element array may be adjusted according to actual measurement requirements. In the case of a special battery structure, the battery shape may be adjusted, and the battery shape is not necessarily a quadrangle, and may be arranged in another shape or formed in a one-dimensional array.

The magnetoelectric sensitive element 40 is composed of a magnetoelectric composite and magnets provided at both ends of the magnetoelectric composite. Fig. 2 illustrates the structure of a single magneto-electrically sensitive element 40 that forms an array of magneto-electrically sensitive elements. As shown in fig. 2, magneto-electrically sensitive element 40 includes a magneto-electric composite and a pair of magnets 43. The magnetoelectric composite is formed by combining two layers of magnetostrictive materials 41 and a layer of piezoelectric material 42 located between the two layers of magnetostrictive materials 41 by, for example, adhesion or the like. The magnetostrictive material may be, for example, Terfenol-D, Metglas, and the piezoelectric material may be, for example, PMNT, BaTiO3, PZT, or the like. The two magnets 43 are respectively disposed at two ends of the magnetoelectric composite body and are mainly used for providing an optimal bias magnetic field for the giant magnetostrictive material in the magnetoelectric composite body, and the magnets 43 may be permanent magnets, for example. As shown in fig. 1, each magnetoelectric sensitive element 40 is arranged above the first conductive layer 31 with the direction in which the magnetostrictive material 41 and the piezoelectric material 42 are stacked as the vertical direction, and thereby the magnetoelectric sensitive element array is configured. The arrangement mode can enable the magnetoelectric sensitive element to be positioned between the two conductive layers and can prevent electromagnetic interference. In fig. 1, magnets 43 provided on both sides of the magneto-electric sensitive element 40 are omitted.

[ front-end Circuit ]

A plurality of front-end circuits 50 are provided above the second mechanical support layer 22, specifically above the third conductive layer 33, corresponding to each of the magnetoelectric sensing elements 40 in the magnetoelectric sensing element array. The front-end circuit 50 is used for converting the charge signal output by the magnetoelectric sensing element 40 into a voltage signal, and mainly performs functions of impedance matching, signal amplification, null shift suppression, filtering, and the like with the magnetoelectric sensing element 40, and may be, for example, a common amplification circuit having functions of impedance matching, null shift suppression, filtering, and the like.

By leading out a signal wire 51 with a shielding shell from the magnetoelectric composite of the magnetoelectric sensing element 40 as a signal output end and connecting the signal wire with the signal input end of the front-end circuit 50, when the magnetostrictive material 41 senses the magnetic field fluctuation around the battery, the magnetostrictive material generates telescopic deformation, the deformation acts on the piezoelectric material 42, so that electric charges are formed on the upper surface and the lower surface of the piezoelectric material, and the electric charges are collected by the front-end circuit 50 and converted into measurable electric signals (namely voltage signals). In addition to the signal line 51, the front-end circuit is provided with a plurality of other wires such as a signal line for transmitting a signal to a signal processing unit not shown.

[ Flexible conductive layer ]

In addition, a flexible conductive layer is further disposed in the magnetic imaging array sensor 100, and the flexible conductive layer includes a first flexible conductive layer 61 and a second flexible conductive layer 62, which are mainly used for flexibly connecting the conductive layers and the magnetoelectric sensitive element 40. Specifically, as shown in fig. 1, a first flexible conductive layer 61 is disposed between the first conductive layer 31 and the bottom of the magnetoelectric sensing element array, and a second flexible conductive layer 62 is disposed between the top of the magnetoelectric sensing element array and the second conductive layer 32. The flexible conductive layers can be formed by flexible conductive silver adhesive, a flexible circuit board and the like, and mainly play a role in ensuring flexible connection between the conductive layers and the magnetoelectric sensitive element 40, reducing clamping in the up-down direction of the magnetoelectric sensitive element 40 and improving magnetoelectric response of the magnetoelectric sensitive element 40.

The first flexible conductive layers 61 are respectively laid between the upper surface of the first conductive layer 31 and the bottom of each magnetoelectric sensitive element 40 in a manner of extending in the horizontal direction. The second flexible conductive layers 62 are respectively and correspondingly disposed on the top of each magnetoelectric sensing element 40, and are connected to the input end of the corresponding front-end circuit 50 through the signal line 51 with the shielding shell, and the signal line 51 can input the signal sensed by the magnetoelectric sensing element 40 to the front-end circuit 50 for signal conditioning. In the present embodiment, the signal line 51 is inserted through the second conductive layer 32, the second mechanical support layer 22, and the third conductive layer 33 and connected to the input terminal of the front circuit 50, but the present invention is not limited thereto, and the signal line 51 may be connected to the input terminal of the front circuit 50 by bypassing the above layers from the side.

As described above, in the present invention, a mechanical support layer for supporting is provided in the outer shield layer 10, a conductive layer for shielding electromagnetic interference in the environment is laid on the inner surface of the mechanical support layer, a plurality of flexible conductive layers for flexible connection are laid on the inner surfaces of the conductive layers, a magnetoelectric sensitive element array in which a plurality of magnetoelectric sensitive elements 40 are arranged in an array is provided between the flexible conductive layers, and signal lines are led out from the magnetoelectric sensitive elements 40 and connected to a front circuit provided above the magnetoelectric sensitive elements, respectively, whereby a voltage signal corresponding to a battery magnetic field at a position where each magnetoelectric sensitive element 40 is located can be obtained.

The voltage signals can be converted into magnetic field values through a magnetoelectric effect formula, the current density value of the upper surface of the battery can be obtained by differentiating the magnetic field values, the values are arranged according to respective row and column positions, and a current density distribution diagram of the upper surface of the battery can be obtained by drawing according to the size of the adjacent position values (for example, arrows point to positions with large absolute values). Fig. 3 is a battery internal current density distribution diagram obtained by converting the detection value of the magnetic imaging array sensor 100, (a) shows an example of the internal current density distribution of a healthy battery, and (b) shows an example of the internal current density distribution of a failed battery. As shown in fig. 3 (a) and (b), when a fault such as a short circuit occurs at a certain position inside the battery, the magnetic field of the battery changes at the position, so that the magnetostrictive material 41 is strained in the magnetoelectric sensitive element 40 above the position to generate abnormal electric charges in the piezoelectric material 42, the electric charges are processed by the front-end circuit 50 and a signal processing module (not shown) and converted into abnormal magnetic field values, and an abnormal current density region of the upper surface of the battery is obtained after differentiation. When the abnormal current density area appears in the area, the battery can be judged to have a fault, and the fault position of the battery can be judged through human eye recognition or automatic recognition algorithm and the like.

The invention has the characteristics of simple structure, small volume, low cost and capability of being used at normal temperature. And because the outer shielding layer for forming electrostatic shielding and the conductive layer for shielding electromagnetic interference are arranged, the anti-interference performance is stronger. In addition, the flexible conducting layer which flexibly connects the magnetoelectric sensitive element with the conducting layer is arranged, so that the clamping of the magnetoelectric sensitive element can be reduced, the magnetoelectric response of the magnetoelectric sensitive element is improved, and the spatial resolution is improved. According to the invention, the magnetoelectric sensitive element array consisting of a plurality of magnetoelectric sensitive elements and the front-end circuit arranged above the magnetoelectric sensitive element array can provide fine current density distribution in the battery in a real-time online lossless manner, so that the local fault position of the battery can be accurately positioned according to the current density distribution diagram, the battery fault can be found as soon as possible, the fault battery can be replaced, the occurrence of fire accidents can be avoided, and the use safety of the battery can be improved.

The above embodiments are intended to illustrate and not to limit the scope of the invention, which is defined by the claims, but rather by the claims, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.