Method for testing medium loss of motor considering open-slot effect of stator and rotor and axial flow

Abstract

The motor medium loss testing method considers the slotting effect of the stator and the axial flow. S1. manufacturing an experimental motor and a testing model; S2. testing the no-load loss of the experimental motor and obtaining the no-load input power; S3. testing the motor input power of the experimental motor under the load of the testing model and obtaining the mechanical loss; S4. testing the no-load input power of the experimental motor under the working condition without axial flow; S5. testing the load input power of the experimental motor under the load of different types of testing models; S6. analyzing the influence of the slotting effect on the medium friction loss; S7. testing the no-load input power of the experimental motor under the working condition with axial flow; S8. testing the load input power of the experimental motor under the load of different types of testing models under the working condition with axial flow; S9. analyzing the influence of the axial flow on the motor medium friction loss. The motor medium friction loss change caused by the slotting area can be directly measured, and the accuracy of the motor design is improved.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a method for testing motor dielectric losses that takes into account the stator and rotor trenching effect and axial flow. Background Technology

[0002] For motors filled with a medium, such as open-structure water-immersed motors, the medium generates frictional losses during operation. Current methods for testing this frictional loss in motors typically involve creating a test model with the stator and rotor without grooves, while maintaining the same dimensions as the experimental motor. Losses are measured at the same speed under both assembled and unassembled conditions; the difference between the two measurements represents the frictional loss at that speed. However, this conventional method neglects the effect of grooves on the stator and rotor, making it impossible to determine the frictional loss caused by this effect. Furthermore, it ignores the changes in frictional loss due to axial flow. Because there is currently no precise analytical method for calculating frictional losses that considers both the groove effect and axial flow, the design of grooves in motor design lacks a basis, resulting in low accuracy in calculating frictional losses. When calculating total motor losses, the high uncertainty in the impact of the groove effect and axial flow on overall motor performance leads to uncertainty in the calculated motor temperature field. Therefore, conventional frictional loss testing methods introduce uncertainty into motor design, making it difficult to provide sufficient experimental data for accurate motor design. Summary of the Invention

[0003] To address the problem that conventional dielectric loss testing methods have inherent uncertainties and cannot provide sufficient experimental data to support accurate motor design, this invention provides a method for testing the dielectric friction loss of motors that considers stator and rotor trenching effects and axial flow.

[0004] The technical solution adopted in this invention is:

[0005] A test method for motor dielectric loss considering stator-rotor trenching effect and axial flow includes the following steps:

[0006] S1. Manufacturing experimental motors and test models;

[0007] S2. Test the no-load loss of the experimental motor and obtain the no-load input power;

[0008] S3. Test the input power of the experimental motor when it is under the load of the test model, and calculate the mechanical loss;

[0009] S4. Place the experimental motor in a container filled with the medium and test the no-load input power of the experimental motor under the condition of no axial flow.

[0010] S5. Test the load input power of the experimental motor when it is carrying different types of test model loads;

[0011] S6. Analyze the impact of trenching effect on media friction loss;

[0012] S7. Place the experimental motor in a container filled with the medium, and test the no-load input power of the experimental motor under the condition of axial flow.

[0013] S8. Connect the experimental motor and the test model and place them in a container filled with medium. Under the condition of axial flow, test the load input power of the experimental motor when it is carrying different types of test model loads.

[0014] S9. Analyze the impact of axial flow on the frictional loss of the motor medium.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The medium friction loss test method considering the trenching effect proposed in this invention can directly measure the change in medium friction loss caused by the trench area, thereby improving the accuracy of motor design.

[0017] 2. The test method for medium friction loss considering axial flow proposed in this invention can directly measure the medium friction loss generated in the annular region and the loss change caused by the trenching effect under the condition of axial flow, thereby improving the accuracy of motor temperature field calculation.

[0018] 3. This invention improves the accuracy of calculating the friction loss of the medium, avoiding material waste or excessive temperature rise caused by unreasonable motor design due to inaccurate loss calculation. Attached Figure Description

[0019] Figure 1 This is the test model type of the present invention;

[0020] Figure 2 This invention relates to the experimental motor installation method;

[0021] Figure 3 This is a flowchart of the dielectric friction loss test of the present invention; Detailed Implementation

[0022] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0023] The core idea of ​​this invention is to analyze the influence of stator and rotor grooves and axial flow on the friction loss of the medium based on no-load and load experiments under different working conditions and at the same speed.

[0024] This invention provides a method for testing the dielectric loss of a motor that considers the stator and rotor trenching effect and axial flow, comprising the following steps:

[0025] A. Fabricating experimental motors and test models:

[0026] S1. Manufacturing experimental motors and test models;

[0027] The test model serves as the load for the experimental motor, and its difference from the experimental motor lies in the stator and rotor structures.

[0028] The test models are divided into four categories: neither stator nor rotor is grooved; both stator and rotor are grooved; stator is grooved and rotor is not grooved; and stator is not grooved and rotor is grooved. Figure 1 As shown. Figure 1 (a) Grooves are cut on both the stator and rotor. Figure 1 (b) No grooves are cut for either the stator or the rotor. Figure 1 (c) Grooving is done on the stator, but not on the rotor. Figure 1 (d) Stator without grooves, rotor with grooves;

[0029] The test model is a solid steel structure, which does not generate copper or iron loss.

[0030] B. Experimental testing procedures:

[0031] S2. Test the no-load loss of the experimental motor and obtain the no-load input power;

[0032] The no-load loss of the experimental motor is tested in air through an unloaded experiment. The input power of the experimental motor can be obtained by measuring the terminal voltage and winding current of the motor windings. The no-load input power P0 in air is equal to the iron loss p generated by the experimental motor during operation. Fe Copper consumption p 0Cu Mechanical loss p mec The sum, as shown in equation (1), indicates that copper loss can be obtained by measuring the winding current and winding resistance.

[0033] P0 = p Fe +p 0Cu +p mec (1)

[0034] S3. Test the input power of the experimental motor when it is under the load of the test model, and calculate the mechanical loss;

[0035] In air, at the same rotational speed, the input power of the experimental motor under the load of the test model was tested. Since the experimental motor and the test model are identical in mechanical structure except for the stator and rotor, it can be assumed that the mechanical losses of the experimental motor and different types of test models are the same. The input power P1 of the experimental motor under load is equal to the iron loss p generated by the operation of the experimental motor. Fe Copper consumption p1Cu Mechanical loss p mec Mechanical loss p under test model load mec The sum is shown in equation (2). Considering the small load and the small influence of the magnetic field, the iron loss under load can be considered to be the same as the iron loss under no-load conditions.

[0036] P1=(p Fe +p 1Cu +p mec )+p mec (2)

[0037] Based on the test results of the no-load input power P0 and the load input power P1 in the air, the mechanical loss p can be calculated. mec As shown in equation (3).

[0038] p mec =P1-P0-p 1Cu +p 0Cu (3)

[0039] S4. Place the experimental motor in a container filled with the medium, and test the no-load input power P of the experimental motor under conditions of no axial flow. 0JZ ,

[0040] No-load input power P without axial flow 0JZ Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 0CuJZ Mechanical loss p mec and the friction loss of the medium p JZ The sum is shown in equation (4).

[0041] P 0JZ =p Fe +p 0CuJZ +p mec +p JZ (4)

[0042] S5. Test the load input power of the experimental motor when it is carrying different types of test model loads;

[0043] Connect the experimental motor and the test model and place them in a container filled with a medium, such as... Figure 2 As shown, under the condition of 0 m / s axial flow (i.e., no axial flow), the input power of the experimental motor under different types of test model loads was measured; the load input power P under no axial flow condition was also measured. 1JZ Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 1CuJZ Mechanical loss p mec and the friction loss of the medium p JZ Mechanical loss p under test model loadmec and the friction loss of the medium p xx The sum is shown in equation (5). The dielectric friction loss p xx For the purpose of not specifically referring to the frictional loss of the medium in the test model type, when p xx For p gb At this time, the test model is characterized by a grooved stator and an ungrooved rotor; when p xx For p bg When p represents a test model with a non-grooved stator and a grooved rotor; xx For p gg The time indicates a test model with a stator groove and a rotor groove under load; when p xx For p bb The time indicates a test model with no grooves on the stator and no grooves on the rotor;

[0044] P 1JZ =(p Fe +p 1CuJZ +p mec +p JZ )+(p mec +p xx (5)

[0045] S6. Based on equations (1) to (5), the medium friction loss under the following conditions with no axial flow is obtained by loss separation: neither stator nor rotor is grooved, both stator and rotor are grooved, stator is grooved and rotor is not grooved, and stator is not grooved and rotor is grooved. The influence of the grooving effect on the medium friction loss is analyzed.

[0046] Based on the no-load input power P in the medium 0JZ and load input power P 1JZ The test results can be used to obtain the test model loss P in a medium without axial flow. mx As shown in equation (6).

[0047] P MX =P 1JZ -P 0JZ -p 1CuJZ +p 0CuJZ =p mec +p xx (6)

[0048] Based on the test model loss P in a non-axially flowing medium MX and mechanical loss p mec The calculation results can be used to determine the medium friction loss p when there is no axial flow. xx As shown in equation (7).

[0049] p xx =P MX -pmec (7)

[0050] Based on the frictional loss p of the medium without axial flow xx The effect of trenching on media friction loss under the condition of no axial flow can be obtained, as shown in equation (8).

[0051]

[0052] S7. Place the experimental motor in a container filled with a medium, and test the no-load input power P of the experimental motor under axial flow conditions. 0JZ1 ;

[0053] No-load input power P in the presence of axial flow 0JZ1 Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 0CuJZ1 Mechanical loss p mec and the friction loss of the medium p JZ1 The sum is shown in equation (9).

[0054] P 0JZ1 =p Fe +p 0CuJZ1 +p mec +p JZ1 (9).

[0055] S8. Connect the experimental motor and the test model and place them in a container filled with the medium, such as... Figure 2 As shown, under the condition of axial flow, the load input power of the experimental motor under different types of test model loads was tested.

[0056] Load input power P in the presence of axial flow 1JZ1 Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 1CuJZ1 Mechanical loss p mec and the friction loss of the medium p JZ1 Mechanical loss p under test model load mec and the friction loss of the medium p xx1 The sum is shown in equation (10).

[0057] P 1JZ1 =(p Fe +p 1CuJZ1 +p mec +p JZ )+(p xx1 +p mec (10).

[0058] S9. Based on equations (1), (2), (9), and (10), the medium friction loss under the following conditions with axial flow is obtained by loss separation: neither stator nor rotor is grooved, both stator and rotor are grooved, stator is grooved and rotor is not grooved, and stator is not grooved and rotor is grooved. The influence of axial flow on the medium friction loss of the motor is analyzed, providing experimental data support for the design of motor grooves.

[0059] Based on the no-load input power P when axial flow exists 0JZ1 and load input power P 1JZ1 The test results show the loss P of the test model when axial flow is present. mx1 As shown in equation (11).

[0060] P MX1 =P 1JZ1 -P 0JZ1 -p 1CuJZ1 +p 0CuJZ1 =p mec +p xx1 (11)

[0061] Based on the test model loss P when axial flow exists MX1 and mechanical loss p mec The calculation results can be used to determine the medium friction loss p when there is axial flow. xx1 As shown in equation (12).

[0062] p xx1 =P MX1 -p mec (12)

[0063] Based on the frictional loss p of the medium when there is axial flow xx1 Frictional loss p of the medium without axial flow xx The effect of axial flow on the friction loss of the medium can be obtained, as shown in equation (13).

[0064]

[0065] C. Data Analysis:

[0066] The results of the measurements, considering the effects of stator and rotor trenching and axial flow on the frictional loss of the motor medium, provide experimental data support for motor design.

[0067] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method for testing the dielectric loss of a motor considering the stator-rotor trenching effect and axial flow, characterized in that: Includes the following steps: S1. Manufacturing experimental motors and test models; The test model in S1 serves as the load for the experimental motor. The test models are divided into four categories: neither the stator nor the rotor is grooved, both the stator and the rotor are grooved, the stator is grooved and the rotor is not grooved, and the stator is not grooved and the rotor is grooved. S2. Test the no-load loss of the experimental motor and obtain the no-load input power; S3. Test the input power of the experimental motor when it is under the load of the test model, and calculate the mechanical loss; S4. Place the experimental motor in a container filled with the medium and test the no-load input power of the experimental motor under the condition of no axial flow. S5. Test the load input power of the experimental motor when it is carrying different types of test model loads; The calculation method for the load input power in S5 is as follows: The experimental motor and the test model were connected and placed in a container filled with a medium. Under the condition of no axial flow, the load input power of the experimental motor was tested when it was loaded with different types of test model loads. Load input power P without axial flow 1JZ Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 1CuJZ Mechanical loss p mec and the friction loss of the medium p JZ Mechanical loss p under test model load mec and the friction loss of the medium p xx The sum of the dielectric friction loss p xx For the purpose of not specifically referring to the frictional loss of the medium in the test model type, when p xx For p gb At this time, the test model is characterized by a grooved stator and an ungrooved rotor; when p xx For p bg When p represents a test model with a non-grooved stator and a grooved rotor; xx For p gg The time indicates a test model with a stator groove and a rotor groove under load; when p xx For p bb The time indicates a test model with no grooves on the stator and no grooves on the rotor; (5)； S6. Analyze the impact of trenching effect on media friction loss; By loss separation, the medium friction loss was obtained under the following conditions: no axial flow, no grooves for both stator and rotor, grooves for both stator and rotor, grooves for stator and no grooves for rotor, and no grooves for stator and grooves for rotor. The influence of the grooving effect on the medium friction loss was analyzed. The specific process is as follows: Based on the no-load input power P in the medium 0JZ and load input power P 1JZ The test results yielded the test model loss P in a medium without axial flow. mx , (6) Based on the test model loss P in a non-axially flowing medium MX and mechanical loss p mec The calculation results can be used to determine the medium friction loss p when there is no axial flow. xx , (7) Based on the frictional loss p of the medium without axial flow xx This allows us to determine the effect of the trenching effect on the frictional loss of the medium under conditions without axial flow. (8)； S7. Place the experimental motor in a container filled with the medium, and test the no-load input power of the experimental motor under the condition of axial flow. S8. Connect the experimental motor and the test model and place them in a container filled with medium. Under the condition of axial flow, test the load input power of the experimental motor when it is carrying different types of test model loads. S9. Analyze the effect of axial flow on the frictional loss of the motor medium. By separating the losses, we obtained the medium friction losses under the following conditions: no grooves in both the stator and rotor, grooves in both the stator and rotor, grooves in the stator and no grooves in the rotor, and no grooves in the stator and grooves in the rotor. We analyzed the influence of axial flow on the medium friction loss of the motor and provided experimental data support for the design of motor grooves. The specific process is as follows: Based on the no-load input power P when axial flow exists 0JZ1 and load input power P 1JZ1 The test results show the loss P of the test model when axial flow is present. mx1 , (11) Based on the test model loss P when axial flow exists MX1 and mechanical loss p mec The calculation results can be used to determine the medium friction loss p when there is axial flow. xx1 , (12) Based on the frictional loss p of the medium when there is axial flow xx1 Frictional loss p of the medium without axial flow xx The effect of axial flow on the frictional loss of the medium can be determined. (13)。 2. The method for testing the dielectric loss of a motor considering the stator and rotor trenching effect and axial flow according to claim 1, characterized in that: The specific method for testing the no-load loss of the experimental motor and obtaining the no-load input power in S2 is as follows: The no-load loss of the experimental motor was tested in air under no-load conditions. The input power of the experimental motor was obtained by measuring the terminal voltage and winding current of the motor windings. The no-load input power P0 in air is equal to the iron loss p generated by the experimental motor during operation. Fe Copper consumption p 0Cu Mechanical loss p mec The sum of copper losses is obtained by measuring the winding current and winding resistance. (1)。 3. The method for testing motor dielectric loss considering stator and rotor trenching effect and axial flow according to claim 2, characterized in that: The calculation method for the motor input power and mechanical loss in S3 is as follows: Under load, the input power P1 of the experimental motor is equal to the iron loss p generated by the experimental motor during operation. Fe Copper consumption p 1Cu Mechanical loss p mec Mechanical loss p under test model load mec The sum of (2)； Based on the test results of the no-load input power P0 and the load input power P1 in the air, the mechanical loss p can be calculated. mec , (3)。 4. The method for testing motor dielectric loss considering stator and rotor trenching effect and axial flow according to claim 3, characterized in that: The calculation method for the no-load input power in S4 is as follows: No-load input power P without axial flow 0JZ Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 0CuJZ Mechanical loss p mec and the friction loss of the medium p JZ The sum of (4)。 5. The method for testing motor dielectric loss considering stator and rotor trenching effect and axial flow according to claim 4, characterized in that: The calculation method for the no-load input power in S7 is as follows: No-load input power P in the presence of axial flow 0JZ1 Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 0CuJZ1 Mechanical loss p mec and the friction loss of the medium p JZ1 The sum of (9)。 6. The method for testing the dielectric loss of a motor considering the stator and rotor trenching effect and axial flow according to claim 5, characterized in that: The method for calculating the load input power in S8 is as follows: Load input power P in the presence of axial flow 1JZ1 Equal to the iron loss p generated by the experimental motor operation Fe Copper consumption p 1CuJZ1 Mechanical loss p mec and the friction loss of the medium p JZ1 Mechanical loss p under test model load mec and the friction loss of the medium p xx1 The sum of (10)。

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