Measuring device for multi-angle oriented silicon steel sheet

Abstract

The invention discloses a measuring device for a multi-angle oriented silicon steel sheet. Belongs to the technical field of motors and comprises a rectangular magnetic ring serving as a main magnetic circuit and a rotatable laminated silicon steel sheet serving as a test sample. The magnetic performance parameters, including magnetic induction intensity, magnetic field intensity, specific total loss, magnetic conductivity and the like, of the oriented silicon steel sheet at different angles are calculated by applying alternating voltage to the primary side winding and combining primary side winding measurement current and secondary side winding measurement induction voltage. Multi-angle measurement is achieved by rotating the sample, the sample does not need to be cut repeatedly, the measurement efficiency is remarkably improved, material loss is reduced, and the method is suitable for rapid and accurate performance evaluation of the motor iron core material.

Description

Technical Field

[0001] This invention belongs to the field of motor technology; specifically, it relates to a measuring device for multi-angle oriented silicon steel sheets. Background Technology

[0002] With the rapid development of electric motors, the market has placed higher demands on the manufacturing of high-efficiency motors. Due to the superior magnetic properties of grain-oriented silicon steel sheets, including low hysteresis loss, low eddy current loss, and high saturation induction intensity, these characteristics make them an ideal choice for manufacturing high-efficiency motors and transformers. However, after the grain-oriented silicon steel sheets are prepared, precise measurements are required to ensure they meet performance requirements. Currently, some traditional measurement methods, such as the Epstein square method, are widely used for the performance measurement of grain-oriented silicon steel sheets, mainly including the measurement of magnetic properties and specific total loss. However, measuring multi-angle grain-oriented silicon steel sheets often requires cutting them from different angles and placing them into the measuring device; this process is time-consuming, labor-intensive, and consumes a great deal of materials. These limitations affect the production efficiency and performance optimization of motors using grain-oriented silicon steel sheets as the core material. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a measuring device that solves the problem of time-consuming and laborious measurement of multi-angle oriented silicon steel sheets, and enables simple and rapid measurement of the performance of oriented silicon steel sheets at different angles.

[0004] Technical solution: The measuring device for multi-angle oriented silicon steel sheets of the present invention includes a rectangular magnetic ring as the main magnetic circuit. The preparation method is as follows: first, the silicon steel sheet mother plate is cut into strips along the rolling direction, and then the strips are stacked to form a rectangular magnetic ring. The bottom side of the rectangular magnetic ring is then cut to form a cylindrical laminated silicon steel sheet.

[0005] Furthermore, in the cutting of the laminated silicon steel sheet, the cutting gap between the rectangular magnetic ring and the laminated silicon steel sheet is controlled to be 1 mm.

[0006] Furthermore, a secondary winding is installed at the cut gap between the rectangular magnetic ring and the laminated silicon steel sheet.

[0007] Furthermore, the secondary winding, i.e., the patch coil, is wound around a cut, laminated silicon steel sheet.

[0008] Furthermore, a primary winding is wound on the other side of the rectangular magnetic ring.

[0009] Furthermore, a power supply and an ammeter are connected to the primary winding, and a voltmeter is connected to the secondary winding.

[0010] Furthermore, the primary winding is made of insulated copper wire, which is uniformly wound around the upper side of the rectangular magnetic ring, with 40 to 80 turns and a length of ≥190mm on the rectangular magnetic ring.

[0011] Furthermore, the effective length of the rectangular magnetic ring is the sum of the circumference of the four corners and the length of the rectangular border.

[0012] Furthermore, the measurement method of the multi-angle oriented silicon steel sheet measuring device is used to measure the induced voltage, and the measurement steps are as follows: Step (1) Rotate the laminated silicon steel sheet to the same orientation as the rectangular magnetic ring, and then measure the material properties in this rolling direction; Step (2) Connect the positive and negative terminals of the power supply to the primary winding of the rectangular magnetic ring, connect the current input terminal of the digital power meter to the primary winding, and connect the voltage input terminal to the secondary winding. Step (3) Select an appropriate magnetic induction intensity with an interval of 0.1; calculate the effective value of the input voltage; The relationship between the power supply input voltage U and the corresponding magnetic induction intensity B is shown in equation (1): (1) In the formula, U This is the effective value of the input voltage. f For the input power frequency, B The magnetic flux density that needs to be measured is... S The cross-sectional area of ​​the sample. N 2 The number of turns of the secondary coil, where S The area is the cross-sectional area of ​​the silicon steel sheet on one side of the sample, i.e., magnetic ring thickness * magnetic ring width * stacking factor, where the stacking factor is 0.85-0.95; the standard Epstein square ring turns are selected from 40 to 80 turns, i.e., to obtain a suitable range of voltage and current. Step (4) The effective value of the magnetic field strength should be calculated from the effective value of the current measured by the effective value ammeter in the circuit. The effective value of the magnetic induction intensity is calculated by equation (2): (2) In the formula, Ĥ N is the effective value of the magnetic field strength, and N1 is the number of turns of the primary coil. Ȋ This represents the peak value of the excitation current. L m The effective magnetic circuit length is defined as the sum of the circumference of the four corners and the length of the rectangular border. Step (5) Calculate the specific total loss: When measuring the loss of laminated silicon steel sheets, calculate the effective mass of the material to obtain the specific total loss of the material; the specific total loss can be calculated by the formula: (3) In the formula, P s This refers to the total loss in the rolling direction. m e The effective mass of the sample magnetic ring is given. P c To measure power with a power meter; Step (6) Measure the magnetic properties of multi-angle stacked oriented silicon steel sheets: After completing the rolling direction measurement, rotate the stacked silicon steel sheets by an angle. Since the overall magnetic path is limited by the stacked silicon steel sheets of the other orientation after rotation, measure the magnetic properties of the material under the other orientation again according to the above steps; plot the BH curve. Step (7) Measure the loss of laminated silicon steel sheets at multiple angles: Since the measured loss is related to the overall effective mass, the loss of laminated silicon steel sheets at more angles is calculated by the following formula: (4) In the formula, P w The total loss of the sample. P c Measure the power of the current power meter. P z The total power measured in the rolling direction. m 1 The effective mass of the rectangular magnetic ring is... m 2 The effective quality of laminated silicon steel sheets.

[0013] Furthermore, in step (2), the positive and negative connection directions should be such that the peak voltage, peak current, and power displayed by the digital power meter are positive.

[0014] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: The measuring device proposed in this invention can quickly and accurately measure the performance of multi-angle oriented silicon steel sheets, and can be used to measure the performance of core materials when designing motors; This invention provides detailed specific example parameters, and its analytical calculation of the axial free mode natural frequency of the rotor verifies the effectiveness of the device by comparing the calculation results with those of the finite element method; This invention provides an effective calculation method for researchers of disc permanent magnet motors to quickly and accurately calculate the rotor natural frequency, laying the foundation for improving the performance of disc permanent magnet motors. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the measuring device in this invention; Figure 2 This is a schematic diagram of the connection circuit of the measuring device in this invention; Figure 3 This is a schematic diagram illustrating the method for calculating the effective magnetic circuit length of the rectangular magnetic ring in this invention; Figure 4 This is the BH curve measured in this invention; Figure 5 This is the BP curve measured in this invention; In the diagram, 1 is a rectangular magnetic ring, 2 is the primary winding, 3 is the secondary winding, and 4 is a laminated silicon steel sheet. Detailed Implementation

[0016] The specific technical solution of the present invention will be further described in detail below with reference to specific examples.

[0017] As shown in the figure in Example 1, the measuring device for multi-angle oriented silicon steel sheets of the present invention specifically involves: when an AC voltage is applied to a rectangular magnetic ring 1, the resulting changing current will form a changing magnetic field. When this magnetic field passes through the silicon steel sheet sample, it will cause magnetization in the silicon steel sheet, thereby generating magnetic flux.

[0018] The response of magnetic flux to the applied magnetic field strength is obtained by measuring the induced voltage on the coil. This device uses two coils with equal turns, continuously wound, sharing the same magnetic circuit. When an alternating voltage is applied to the primary coil, an alternating magnetic field is generated. This alternating magnetic field passes through a magnetic ring made of silicon steel sheet, causing magnetization within the silicon steel sheet. The magnetic flux within the silicon steel sheet is the product of the magnetic field strength H and the permeability μ of the silicon steel sheet. The magnetic flux can be indirectly measured by measuring the induced voltage on the coil. As the alternating voltage changes, the change in the induced voltage in the coil is proportional to the change in magnetic flux. This is because the change in magnetic flux leads to a change in the magnetic flux linkage in the coil, which in turn causes a change in the induced voltage. By measuring the phase difference and amplitude between the induced voltage and the applied voltage on the coil, the relationship between magnetic flux and magnetic field strength can be determined. By measuring the induced voltage under different voltages and frequencies, the magnetic properties parameters of the silicon steel sheet sample, such as permeability, magnetic flux loss, and magnetic saturation, can be obtained.

[0019] This measuring device was designed to test the material properties of multi-angle oriented silicon steel sheets. First, the silicon steel sheet mother plate is cut into strips along the rolling direction, and then the strips are stacked to form a rectangular magnetic ring 1. Then, the lower side of the rectangular magnetic ring 1 is cut to form a cylindrical part 2 (stacked silicon steel sheet 4). The cut rectangular magnetic ring 1 is part 1. The cutting gap between the two needs to be controlled at about 1 mm.

[0020] Copper wire is wound around the upper side of part one (rectangular magnetic ring 1) to form a primary winding 2, which should be evenly distributed over a length of at least 190 mm; part two (laminated silicon steel sheet 4) is placed back into the slot cut into part one (rectangular magnetic ring 1), and a patch coil is embedded in the gap between part one and part two to form a secondary winding 3, which can wrap around part two (laminated silicon steel sheet 4).

[0021] The measurement steps are as follows: An implementation test of the present invention was conducted on a silicon steel sheet measuring device:

[0022] like Figure 1 The rectangular magnetic ring model shown is formed by stacking the tested rolled silicon steel sheets into a rectangular magnetic ring. The specific parameters and sizes are determined by... Figure 1 Given: Step 1: Cut the bottom of the rectangular magnetic ring 1 to cut out the stacked silicon steel sheet 4, with the cutting gap controlled at about 1mm; measure the mass of each of the two parts; ensure proper insulation protection for the magnetic ring to prevent leakage from affecting the results and the safety of the measurement experiment; use about 10m of insulated copper wire to evenly wrap around the top of the rectangular magnetic ring 1 to generate electromagnetic induction in the rectangular magnetic ring. Step 2: Place the patch coil into the groove and embed part 2. The orientation of part 2 is consistent with the orientation in rectangular magnetic ring 1. Try to make the parts fit together to reduce the air gap and make the magnetic circuit connected. Connect the primary winding 2 to the power supply and ammeter, and connect the patch coil to the voltmeter. The required magnetic flux density B should vary depending on the material being measured; the effective value of the input voltage should be calculated according to Equation 1 and then input into the power supply sequentially, and the peak current and effective power value should be recorded; the measured frequencies are 50Hz, 100Hz, 200Hz, 400Hz, 600Hz, 800Hz, and 1000Hz. Step 3: Calculate the magnetic field strength H and the specific total loss using the recorded peak current and effective power values; use the following formula: (5) (6) In the formula, Ĥ This is the effective value of the magnetic field strength, measured in amperes per meter (A / m). N 1 This refers to the number of turns of the primary winding. Ȋ This represents the peak value of the excitation current, measured in amperes (A). L m The effective magnetic circuit length; P s The specific total loss in the rolling direction is expressed in watts per kilogram (W / kg). m e The effective mass of the sample magnetic ring is expressed in kilograms (kg). Pc A power meter measures power, with the unit being watts (W). Step four: After measurement, rotate part two to the desired orientations (15 degrees, 30 degrees, etc.); repeat the experiment. Note that the amount of wear and tear is calculated using the following formula: (7) In the formula, P w The total loss of the sample is expressed in watts per kilogram (W / kg). P c The power is measured by the current power meter, in watts (W). P z Total power measured in the rolling direction, in watts (W). m 1 The effective mass of part one is expressed in kilograms (kg). m 2 The effective mass of part two is expressed in kilograms (kg). After completing the above steps, the BH curve and BP curve of silicon steel can be plotted as follows: Figure 4-5 As shown.

Claims

1. A measuring device for multi-angle oriented silicon steel sheets, characterized in that, The rectangular magnetic ring (1), which serves as the main magnetic circuit, is prepared by first cutting the silicon steel sheet into strips along the rolling direction, and then stacking the strips to form a rectangular magnetic ring (1). The lower side of the rectangular magnetic ring (1) is then cut to form a cylindrical stacked silicon steel sheet (4).

2. The measuring device for multi-angle oriented silicon steel sheets according to claim 1, characterized in that, In cutting the laminated silicon steel sheet (4), the cutting gap between the rectangular magnetic ring (1) and the laminated silicon steel sheet (4) is controlled at 1 mm.

3. The measuring device for multi-angle oriented silicon steel sheets according to claim 2, characterized in that, A secondary winding (3) is installed at the cut gap between the rectangular magnetic ring (1) and the stacked silicon steel sheet (4).

4. The measuring device for multi-angle oriented silicon steel sheets according to claim 3, characterized in that, The secondary winding (3) is a patch coil, which is wound around a cut laminated silicon steel sheet (4).

5. The measuring device for multi-angle oriented silicon steel sheets according to claim 3, characterized in that, A primary winding (2) is wound on the other side of the rectangular magnetic ring (1).

6. The measuring device for multi-angle oriented silicon steel sheets according to claim 5, characterized in that, A power supply and an ammeter are connected to the primary winding (2); a voltmeter is connected to the secondary winding (3).

7. The measuring device for multi-angle oriented silicon steel sheets according to claim 5, characterized in that, The primary winding (2) is an insulated copper wire that is evenly wound on the upper side of the rectangular magnetic ring (1). The number of turns is 40 to 80, and the length of the winding on the rectangular magnetic ring (1) is ≥190mm.

8. The measuring device for multi-angle oriented silicon steel sheets according to claim 1, characterized in that, The effective length of the rectangular magnetic ring (1) is the sum of the circumference of the four corners and the length of the rectangular border.

9. A measurement method for a measuring device for multi-angle oriented silicon steel sheets as described in any one of claims 1-8, used for measuring induced voltage, characterized in that, The measurement steps are as follows: Step (1) Rotate the laminated silicon steel sheet (4) to the same orientation as the rectangular magnetic ring (1), and then measure the properties of the material in this rolling direction; Step (2) Connect the positive and negative terminals of the power supply to the primary winding (2) of the rectangular magnetic ring (1), connect the current input terminal of the digital power meter to the primary winding (2), and connect the voltage input terminal to the secondary winding (3). Step (3) Select an appropriate magnetic induction intensity with an interval of 0.1; calculate the effective value of the input voltage; The relationship between the power supply input voltage U and the corresponding magnetic induction intensity B is shown in equation (1): （1） In the formula, U This is the effective value of the input voltage. f For the input power frequency, B The magnetic flux density that needs to be measured is... S The cross-sectional area of ​​the sample. N 2 The number of turns of the secondary coil, where S The area is the cross-sectional area of ​​the silicon steel sheet on one side of the sample, i.e., magnetic ring thickness * magnetic ring width * stacking factor, where the stacking factor is 0.85-0.95; the standard Epstein square ring turns are selected from 40 to 80 turns, i.e., to obtain a suitable range of voltage and current. Step (4) The effective value of the magnetic field strength is calculated from the effective value of the current measured by the effective value ammeter in the circuit. The effective value of the magnetic induction intensity is calculated by equation (2): （2） In the formula, Ĥ N is the effective value of the magnetic field strength, and N1 is the number of turns of the primary coil. Ȋ This represents the peak value of the excitation current. L m The effective magnetic circuit length is defined as the sum of the circumference of the four corners and the length of the rectangular border. Step (5) Calculate the specific total loss: When measuring the loss of the laminated silicon steel sheet (4), calculate the effective mass of the material to obtain the specific total loss of the material; the specific total loss can be calculated by formula (4): （3） In the formula, P s This refers to the total loss in the rolling direction. m e The effective mass of the sample magnetic ring is given. P c To measure power with a power meter; Step (6) Measure the magnetic properties of stacked oriented silicon steel sheets (4) at different angles: After completing the rolling direction measurement, rotate the stacked silicon steel sheets (4) by an angle. Since the overall magnetic path is restricted by the stacked silicon steel sheets (4) of the other orientation after rotation, measure the magnetic properties of the material under the other orientation again according to the above steps; plot the BH curve. Step (7) Measure the loss of the laminated grain-oriented silicon steel sheet (4) at different angles: Since the measured loss is related to the overall effective mass, the loss of the laminated grain-oriented silicon steel sheet (4) under another orientation is calculated by the following formula: （4） In the formula, P w The total loss of the sample. P c Measure the power of the current power meter. P z The total power measured in the rolling direction. m 1 The effective mass of the rectangular magnetic ring (1) is... m 2 The effective quality of the laminated silicon steel sheets (4).

10. The measurement method of the measuring device for multi-angle oriented silicon steel sheets according to claim 9, characterized in that, In step (2), the positive and negative connection directions should be such that the peak voltage, peak current and power displayed by the digital power meter are positive.

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