A continuous iron loss measuring device for electrical steel sheets

Abstract

The present invention relates to a device and method for measuring continuous iron loss of an electrical steel sheet, wherein the device comprises an internal frame, a cylinder, an external frame, an induction coil, an excitation coil, an air magnetic flux compensation coil and a magnetic field coil; the internal frame is supported and controlled by the cylinder and is arranged in the external frame so as to be movable up and down; the induction coil is wound around the center of the external frame and is close to the external frame, the excitation coil is fully wound around the external frame and covers the induction coil; the air magnetic flux compensation coil is wound around the internal frame, the magnetic field coil is closely mounted on the air magnetic flux compensation coil and is located at the center above the internal frame. The present invention can well compensate for the air magnetic flux in the induction coil, so that the magnetic field strength and magnetic flux density in the electrical steel sheet can be accurately measured, thereby accurately measuring the magnetic properties of the electrical steel sheet.

Description

Technical Field

[0001] The invention relates to the field of electrical steel sheet measurement, and in particular to a device for measuring continuous iron loss of electrical steel sheets. Background Art

[0002] Electrical steel sheets are soft magnetic alloys with excellent performance, including silicon steel sheets, Permalloy, amorphous and nanocrystalline materials, and are important magnetic materials that are indispensable in various motors and transformers. The existing international measurement standards for electrical steel sheets are based on closed magnetic circuit methods, such as the Epstein square circle method, the single-piece permeameter method, and the ring sample method, which are not suitable for continuous iron loss measurement on electrical steel sheet production lines. The continuous iron loss measurement wireframe is installed on the production line and must be open magnetic circuit.

[0003] The patent number CN1928581A, "A method, coil and system for online detection of magnetic properties of silicon steel", designs a measuring wire frame, which is composed of a skeleton, a measuring coil and an excitation coil from the inside to the outside. The measuring coil includes a measuring coil for measuring magnetic induction and iron loss and a coil for measuring the magnetic field. The coils are isolated by an insulating layer, and a cavity matching the lateral dimensions of the silicon steel production line is left in the skeleton. In the wire frame structure of this scheme, the magnetic field coil is far away from the electrical steel sheet, and the magnetic field strength inside the electrical steel sheet cannot be accurately measured. The magnetic field coil method requires that the magnetic field coil be close to the surface of the electrical steel sheet to be measured in order to meet the continuous boundary conditions of the tangent component of the magnetic field strength. In addition, there is no air flux compensation coil, and there is a lack of an effective method for air flux compensation.

[0004] The invention patent with the patent number ZL201310745424.6, "A Continuous Iron Loss Measurement Device for Electrical Steel", designs a measurement wireframe, which includes a skeleton, an air flux compensation coil, an induction coil, an excitation coil, a DC magnetic field compensation coil and a loop coil from the inside to the outside, and each coil is isolated by an insulating layer; the opening size of the skeleton needs to allow the electrical steel to pass through the skeleton cavity; the air flux compensation coil is used to offset the magnetic induction intensity generated by the air surrounded by the induction coil; the excitation coil is used to apply a magnetic field to the electrical steel; the DC magnetic field compensation coil is used to apply a DC magnetic field in the opposite direction to the environmental field and dynamically adjustable; the loop coil is used to measure the size of the loop magnetic field. The wireframe structure of the invention can correct the effective magnetic path length, dynamically adjust the error caused by the geomagnetic field and the surrounding DC magnetic field to the silicon steel measurement, and meet the measurement conditions of the Ampere loop current method. This scheme is based on the Ampere loop current method. Once the iron loss of the electrical steel sheet on the production line changes greatly, the effective magnetic path length will also change greatly. This method is not well applicable to continuous iron loss measurement. In addition, the air area surrounded by the air flux compensation coil is much smaller than the air area surrounded by the induction coil, and the magnetic field distribution in the air in the wire frame changes with the performance of the electrical steel sheet, and the air flux cannot be accurately compensated. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a continuous iron loss measuring device for electrical steel sheets, which can well compensate for the air flux in the induction coil, so that the magnetic field strength and flux density in the electrical steel sheets can be accurately measured, thereby accurately measuring the magnetic properties of the electrical steel sheets.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an electrical steel sheet continuous iron loss measuring device, including an electrical steel sheet continuous iron loss measuring wire frame, the electrical steel sheet continuous iron loss measuring wire frame includes an internal frame, a cylinder, an external frame, an induction coil, an excitation coil, an air flux compensation coil and a magnetic field coil; the internal frame is supported and controlled by the cylinder, and is arranged in the external frame so as to be movable up and down; the induction coil is wound around the center position of the external frame and is tightly attached to the external frame, the excitation coil is fully wound around the external frame and covers the induction coil; the air flux compensation coil is wound around the internal frame, the magnetic field coil is tightly installed on the air flux compensation coil, and is located at the center position above the internal frame.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the electrical steel sheet continuous iron loss measurement wireframe is used to measure the continuous iron loss of the electrical steel sheet. During measurement, the electrical steel sheet passes through the external frame along the front and rear directions of the external frame, and the magnetic field coil is close to the lower surface of the electrical steel sheet.

[0009] Furthermore, it also includes a through-beam photoelectric sensor, which is installed in front of the outside of the electrical steel sheet continuous iron loss measurement wire frame, located on the left and right sides below the electrical steel sheet, and electrically connected to the cylinder.

[0010] Furthermore, the internal frame and the external frame are both made of non-magnetic non-metallic materials.

[0011] Furthermore, alternating current and direct current flow through the excitation coil.

[0012] Furthermore, the induction coil, the air flux compensation coil and the magnetic field coil are all located in a uniform area of ​​the wire frame magnetic field generated by the excitation coil.

[0013] Furthermore, the magnetic field coil is specifically a flat hollow coil wound by enameled wire, and the length of the magnetic field coil is equal to the length of the induction coil.

[0014] Furthermore, the length of the air flux compensation coil is equal to the length of the induction coil.

[0015] Furthermore, the hollow area of ​​the magnetic field coil is half of the area surrounded by the induction coil.

[0016] Based on the above-mentioned device for measuring continuous iron loss of an electrical steel sheet, the present invention also provides a method for measuring continuous iron loss of an electrical steel sheet.

[0017] A method for measuring continuous iron loss of an electrical steel sheet comprises the following steps:

[0018] The continuous iron loss measuring wire frame of the electrical steel sheet in the continuous iron loss measuring device for electrical steel sheets as described above is installed transversely on the electrical steel sheet production line, so that the electrical steel sheet to be measured passes through the outer frame along the front and rear directions of the outer frame, and the magnetic field coil is closely attached to the lower surface of the electrical steel sheet;

[0019] AC current and DC current are passed through the excitation coil, wherein the AC current in the excitation coil excites the electrical steel sheet, and the DC current in the coil compensates for the ambient DC magnetic field;

[0020] During normal operation, the magnetic field strength inside the electrical steel sheet is measured by the magnetic field coil that is close to the lower surface of the electrical steel sheet; the air compensation coil compensates the air magnetic flux of the induction coil, and then the magnetic flux density inside the electrical steel sheet is measured by the induction coil;

[0021] When there is a protrusion under the electrical steel sheet, the control cylinder moves to move the magnetic field coil away from the electrical steel sheet. After the protrusion under the electrical steel sheet passes, the control cylinder drives the magnetic field coil to return to normal working state.

[0022] The beneficial effects of the present invention are as follows: in the device and method of the present invention, the electrical steel sheet works under the condition of an open magnetic circuit, the magnetic field coil is close to the surface of the electrical steel sheet, the air magnetic flux compensation coil is close to the magnetic field coil, and the hollow area of ​​the magnetic field coil is half of the area surrounded by the induction coil. According to the symmetric distribution of the air magnetic field between the upper and lower parts of the electrical steel sheet in the wire frame, the air magnetic flux in the induction coil can be well compensated, so that the magnetic field strength and magnetic flux density in the electrical steel sheet can be accurately measured, thereby accurately measuring the magnetic properties of the electrical steel sheet. In addition, the internal skeleton can move up and down according to the external defects of the electrical steel sheet on the production line; during normal operation, the magnetic field coil is close to the lower surface of the electrical steel sheet, and the internal magnetic field strength of the electrical steel sheet can be accurately measured; the air flux compensation coil is wound on the inner skeleton, and the enclosed air area is increased by dozens of times compared to the others wound on the outer skeleton, so the signal strength is also increased by dozens of times, which can better compensate for the air flux of the induction coil, thereby accurately measuring the magnetic flux density inside the electrical steel sheet; once there is a protrusion under the electrical steel sheet, the output of the photoelectric sensor in front of the external skeleton changes, and the cylinder is driven to move, so that the magnetic field coil and the air flux compensation coil are away from the electrical steel sheet, and the normal operation is resumed after the electrical steel sheet with the protrusion below passes through the wire frame. This design not only achieves accurate measurement but also prevents accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A top view of a device for measuring continuous iron loss of electrical steel sheets according to the present invention;

[0024] Figure 2 for Figure 1 AA' section view;

[0025] Figure 3 for Figure 1 BB' cross-sectional view;

[0026] Figure 4 The present invention is a flow chart of a method for measuring continuous iron loss of an electrical steel sheet.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 10. Wireframe for continuous iron loss measurement of electrical steel sheet, 1. Internal frame, 2. Cylinder, 3. External frame, 4. Induction coil, 5. Excitation coil, 6. Air flux compensation coil, 7. Magnetic field coil, 8. Electrical steel sheet, 9. Through-beam photoelectric sensor. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] like Figure 1 , Figure 2 and Figure 3 As shown, an electrical steel sheet continuous iron loss measurement device includes an electrical steel sheet continuous iron loss measurement wireframe 10, which is used to measure the continuous iron loss of an electrical steel sheet 8, and includes an internal skeleton 1, a cylinder 2, an external skeleton 3, an induction coil 4, an excitation coil 5, an air flux compensation coil 6 and a magnetic field coil 7; the internal skeleton 1 is supported and controlled by the cylinder 2, and is arranged in the external skeleton 3 so as to be movable up and down (two cylinders 2 are provided, both of which are located outside the external skeleton 3, and under the support of the two cylinders, the internal skeleton 1 runs through the external skeleton 3); the induction coil 4 is wound around the center position of the external skeleton 3 and is close to the external skeleton 3, the excitation coil 5 is fully wound around the external skeleton 3 and covers the induction coil 4; the air flux compensation coil 6 is wound around the internal skeleton 1, and the magnetic field coil 7 is closely installed on the air flux compensation coil 6 and is located at the center position above the internal skeleton 1.

[0031] During measurement, the electrical steel sheet continuous iron loss measurement wireframe 10 is horizontally installed on the electrical steel sheet production line, the electrical steel sheet 8 passes through the external skeleton 3 along the front and rear directions of the external skeleton 3, and the magnetic field coil 7 is close to the lower surface of the electrical steel sheet 8.

[0032] Preferably, the electrical steel sheet continuous iron loss measuring device further comprises a through-beam photoelectric sensor 9 (one transmitting end and one receiving end), which is installed in front of the outside of the electrical steel sheet continuous iron loss measuring wireframe 10, and is located on the left and right sides below the electrical steel sheet 8, and is electrically connected to the cylinder 2. Specifically, the through-beam photoelectric sensor 9 is installed below the electrical steel sheet 8, about 1 meter in front of the external frame (related to the running speed of the electrical steel sheet and the cylinder action time). When there is a protrusion below the electrical steel sheet 8, the light path of the through-beam photoelectric sensor 9 is blocked, and the through-beam photoelectric sensor 9 drives the cylinder 2 to move downward, so that the magnetic field coil 7 and the air flux compensation coil 6 are away from the electrical steel sheet 8, and then return to their original positions after normal.

[0033] Preferably, the internal skeleton 1 and the external skeleton 3 are both made of non-magnetic non-metallic materials. The internal skeleton 1 and the external skeleton 3 must be strong enough to support the winding of various coils without deformation. The internal skeleton 1 is placed inside the external skeleton 3, and the side gap between the internal skeleton 1 and the external skeleton 3 is as small as possible while ensuring free up and down movement, so that the air flux compensation coil 6 covers more area.

[0034] Preferably, an AC current and a DC current are passed through the excitation coil 5. The AC current in the excitation coil 5 realizes the AC excitation of the electrical steel sheet 8, and the DC current in the excitation coil 5 realizes the compensation function of the environmental DC magnetic field (geomagnetic field); the excitation coil 5 must be flat and uniform to ensure that the magnetic field in the center of the wire frame is uniform. The impedance of the excitation coil 5 is as small as possible, which can reduce the power requirement of the excitation power supply.

[0035] Preferably, the induction coil 4, the air magnetic flux compensation coil 6 and the magnetic field coil 7 are all in the uniform area of ​​the wire frame magnetic field generated by the excitation coil 5. The length of the external skeleton 3 should be long enough (greater than 1000 mm) to ensure the length of the excitation coil 5, thereby ensuring that the induction coil 4, the magnetic field coil 7 and the air magnetic flux compensation coil 6 are in the uniform area of ​​the wire frame magnetic field.

[0036] The induction coil 4 is about 200 mm long and is located in the uniform magnetic field area of ​​the wire frame. The induced voltage is caused by two parts: the air magnetic flux and the internal magnetic flux of the electrical steel sheet 8.

[0037] Preferably, the magnetic field coil 7 is a flat hollow coil wound by enameled wire, and its thickness should be as thin as possible (less than 1 mm), and the length of the magnetic field coil 7 is equal to the length of the induction coil 4. For the convenience of calibration, the length and width of the magnetic field coil 7 generally do not exceed 200 mm, and it is wound by using the thinnest enameled wire (<=0.1 mm), and its turn area is about 1 square meter.

[0038] Preferably, the length of the air flux compensation coil 6 is equal to the length of the induction coil 4. The magnetic flux density inside the electrical steel sheet 8 is obtained only after the induced voltage is compensated by the air flux compensation coil. The air flux compensation coil surrounds as much air area as possible under conditions permitting.

[0039] Preferably, the hollow area of ​​the magnetic field coil 7 is half of the area surrounded by the induction coil 4 .

[0040] In order to accurately measure the magnetic properties of electrical steel sheets, the internal magnetic field strength and magnetic flux density of the electrical steel sheets must be accurately measured. The traditional current method is not well suited for the measurement of continuous iron loss of electrical steel sheets. The present invention adopts a magnetic field coil method, which requires the magnetic field coil to be in close contact with the surface of the electrical steel sheet. According to the continuous boundary condition of the tangent component of the magnetic field intensity, the internal magnetic field strength of the electrical steel sheet can be accurately measured. The induction coil is tightly wrapped around the electrical steel sheet, and the internal magnetic flux density of the electrical steel sheet can also be accurately measured. However, the electrical steel sheet production line does not allow such a design. The production line requires that the internal dimensions of the measuring wire frame be as large as possible to prevent the electrical steel sheet from running off track or contacting the wire frame due to defects, causing wire frame damage and electrical steel sheet breakage and other accidents.

[0041] When the present invention is working normally, the magnetic field coil is close to the lower surface of the electrical steel sheet, and the internal magnetic field strength of the electrical steel sheet can be accurately measured; the air flux compensation coil is wound on the inner frame, and the enclosed air area is increased by dozens of times compared to other coils wound on the outer frame, so the signal strength is also increased by dozens of times, which can better compensate the air flux of the induction coil, thereby accurately measuring the magnetic flux density inside the electrical steel sheet. Once there is a protrusion under the electrical steel sheet, the output of the photoelectric sensor in front of the frame changes, and the cylinder is driven to move, so that the magnetic field coil and the air flux compensation coil are away from the electrical steel sheet, and the electrical steel sheet with the protrusion below passes through the wire frame and resumes normal operation. This design not only achieves accurate measurement but also prevents accidents.

[0042] When the continuous iron loss measuring device for an electrical steel sheet of the present invention is used to measure the continuous line loss of the electrical steel sheet, the electrical steel sheet works under an open magnetic circuit condition, the magnetic field coil is in close contact with the surface of the electrical steel sheet, the air magnetic flux compensation coil is in close contact with the magnetic field coil, and the hollow area of ​​the magnetic field coil is half of the area surrounded by the induction coil. According to the symmetric distribution of the air magnetic field between the upper and lower parts of the electrical steel sheet in the wire frame, the air magnetic flux in the induction coil can be well compensated, so that the magnetic field strength and magnetic flux density in the electrical steel sheet can be accurately measured, thereby accurately measuring the magnetic properties of the electrical steel sheet.

[0043] Based on the above-mentioned device for measuring continuous iron loss of an electrical steel sheet, the present invention also provides a method for measuring continuous iron loss of an electrical steel sheet.

[0044] like Figure 4 As shown, a method for measuring continuous iron loss of an electrical steel sheet comprises the following steps:

[0045] The continuous iron loss measuring wire frame of the electrical steel sheet in the continuous iron loss measuring device for electrical steel sheets as described above is installed transversely on the electrical steel sheet production line, so that the electrical steel sheet to be measured passes through the outer frame along the front and rear directions of the outer frame, and the magnetic field coil is closely attached to the lower surface of the electrical steel sheet;

[0046] AC current and DC current are passed through the excitation coil, wherein the AC current in the excitation coil excites the electrical steel sheet, and the DC current in the excitation coil compensates for the ambient DC magnetic field;

[0047] During normal operation, the magnetic field strength inside the electrical steel sheet is measured by the magnetic field coil that is close to the lower surface of the electrical steel sheet; the air compensation coil compensates the air magnetic flux of the induction coil, and then the magnetic flux density inside the electrical steel sheet is measured by the induction coil;

[0048] When there is a protrusion under the electrical steel sheet, the control cylinder moves to move the magnetic field coil away from the electrical steel sheet. After the protrusion under the electrical steel sheet passes, the control cylinder drives the magnetic field coil to return to normal working state.

[0049] In the method of the present invention, the electrical steel sheet works under the condition of open magnetic circuit, the magnetic field coil is close to the surface of the electrical steel sheet, the air flux compensation coil is close to the magnetic field coil, and the hollow area of ​​the magnetic field coil is half of the area surrounded by the induction coil. According to the symmetric distribution of the air magnetic field between the upper and lower parts of the electrical steel sheet in the wire frame, the air flux in the induction coil can be well compensated, so that the magnetic field strength and magnetic flux density in the electrical steel sheet can be accurately measured, thereby accurately measuring the magnetic properties of the electrical steel sheet. In addition, the internal skeleton can move up and down according to the external defects of the electrical steel sheet on the production line; during normal operation, the magnetic field coil is close to the lower surface of the electrical steel sheet, and the internal magnetic field strength of the electrical steel sheet can be accurately measured; the air flux compensation coil is wound on the inner skeleton, and the enclosed air area is increased by dozens of times compared to the others wound on the outer skeleton, so the signal strength is also increased by dozens of times, which can better compensate for the air flux of the induction coil, thereby accurately measuring the magnetic flux density inside the electrical steel sheet; once there is a protrusion under the electrical steel sheet, the output of the photoelectric sensor in front of the external skeleton changes, and the cylinder is driven to move, so that the magnetic field coil and the air flux compensation coil are away from the electrical steel sheet, and the normal operation is resumed after the electrical steel sheet with the protrusion below passes through the wire frame. This design not only achieves accurate measurement but also prevents accidents.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A continuous iron loss measuring device for electrical steel sheets, characterized in that: The invention comprises an electrical steel sheet continuous iron loss measurement wire frame (10), wherein the electrical steel sheet continuous iron loss measurement wire frame (10) comprises an internal frame (1), a cylinder (2), an external frame (3), an induction coil (4), an excitation coil (5), an air flux compensation coil (6) and a magnetic field coil (7); the internal frame (1) is supported and controlled by the cylinder (2) and is arranged in the external frame (3) so as to be movable upward and downward; the induction coil (4) is wound around the center position of the external frame (3) and is closely attached to the external frame (3); the excitation coil (5) is fully wound around the external frame (3) and covers the induction coil (4); the air flux compensation coil (6) is wound around the internal frame (1); the magnetic field coil (7) is closely attached to the air flux compensation coil (6) and is located at the center position above the internal frame (1); The electrical steel sheet continuous iron loss measurement wireframe (10) is used to measure the continuous iron loss of the electrical steel sheet (8). During the measurement, the electrical steel sheet (8) passes through the external frame (3) along the front and rear directions of the external frame (3), and the magnetic field coil (7) is in close contact with the lower surface of the electrical steel sheet (8); It also includes a through-beam photoelectric sensor (9), which is installed in front of the exterior of the electrical steel sheet continuous iron loss measurement wire frame (10) and is located on the left and right sides below the electrical steel sheet (8), and is electrically connected to the cylinder (2); The internal frame (1) and the external frame (3) are both made of non-magnetic non-metallic materials; The magnetic field coil (7) is specifically a flat hollow coil wound by enameled wire, and the length of the magnetic field coil (7) is equal to the length of the induction coil (4).

2. The continuous iron loss measuring device for electrical steel sheets according to claim 1, characterized in that: Alternating current and direct current flow through the excitation coil (5).

3. The continuous iron loss measuring device for electrical steel sheets according to claim 1, characterized in that: The induction coil (4), the air magnetic flux compensation coil (6) and the magnetic field coil (7) are all located within a uniform area of ​​the wireframe magnetic field generated by the excitation coil (5).

4. The continuous iron loss measuring device for electrical steel sheets according to claim 1, characterized in that: The length of the air flux compensation coil (6) is equal to the length of the induction coil (4).

5. The continuous iron loss measuring device for electrical steel sheets according to claim 1, characterized in that: The hollow area of ​​the magnetic field coil (7) is half of the area enclosed by the induction coil (4).

6. A method for measuring continuous iron loss of electrical steel sheets, characterized in that: The following steps are included: The continuous iron loss measuring wire frame of the electrical steel sheet in the continuous iron loss measuring device of any one of claims 1 to 5 is installed horizontally on the electrical steel sheet production line, so that the electrical steel sheet to be measured passes through the outer frame along the front and rear directions of the outer frame, and the magnetic field coil is closely attached to the lower surface of the electrical steel sheet; AC current and DC current are passed through the excitation coil, wherein the AC current in the excitation coil excites the electrical steel sheet, and the DC current in the excitation coil compensates for the ambient DC magnetic field; During normal operation, the magnetic field strength inside the electrical steel sheet is measured by the magnetic field coil that is close to the lower surface of the electrical steel sheet; the air compensation coil compensates the air magnetic flux of the induction coil, and then the magnetic flux density inside the electrical steel sheet is measured by the induction coil; When there is a protrusion under the electrical steel sheet, the control cylinder moves to move the magnetic field coil away from the electrical steel sheet. After the protrusion under the electrical steel sheet passes, the control cylinder drives the magnetic field coil to return to normal working state.

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