Iron loss testing device for evaluating assembling quality of stator iron core

Abstract

The invention relates to the technical field of motors, and discloses an iron loss testing device for evaluating the assembling quality of a stator iron core, which comprises a stator iron core, a stator bracket and an iron core loss tester device. According to the iron core loss tester device, the armature winding which is annularly configured is wound on the yoke part of the rotor iron core, and a rotating magnetic field with any pole number is configured as required by changing the connection mode of the two ends of the annular armature winding, so that various magnetic flux distributions in a motor can be highly and flexibly simulated. The stator iron core is fixedly installed on the stator support, the stator iron core is sleeved on the periphery of the iron core loss tester device through the adjusting support, when the annular armature winding is excited, an air-gap magnetic field similar to that in an alternating current motor can be generated, and the actual iron loss in the motor iron core can be estimated more truly. The device has convenience, accuracy and high efficiency, can be quickly deployed on a production line, evaluates the assembling quality in real time, improves the control level of the assembling quality of the stator core, and reduces the production cost of a motor.

Description

Technical Field

[0001] The invention belongs to the technical field of motors, and in particular relates to an iron loss testing device for evaluating the assembly quality of a stator core. Background Art

[0002] In the field of motor manufacturing, the stator core is one of the key components of the motor, and its performance has an important impact on the overall operating efficiency and reliability of the motor. The assembly process of the stator core directly affects the electromagnetic properties of the core, among which the core loss is an important indicator for evaluating the performance of the core. The increase in core loss not only reduces the efficiency of the motor, but also causes the core to overheat, thus affecting the life and stability of the motor.

[0003] Traditional core loss test methods are often based only on standardized test samples or theoretical models, such as the Epstein square circle data provided by manufacturers. These data usually do not take into account process changes during the manufacturing process and cannot truly reflect the stator core loss after assembly. However, in the actual manufacturing process, the material needs to go through multiple process steps, such as cutting and trimming, layer connection, pressing and fixing processes, etc. These steps will inevitably cause varying degrees of degradation of its magnetic properties. Therefore, how to efficiently and accurately evaluate the assembly quality of the stator core and its iron loss level is an important technical problem in current motor design and production.

[0004] In the prior art, the method for evaluating the iron loss of the stator core mainly relies on the performance test of the whole motor. However, this method has a long test cycle and usually requires the motor to be fully assembled. If the core quality problem is found, it needs to be reworked or remanufactured, resulting in an extended production cycle and increased costs. At the same time, there is a lack of immediate feedback during the assembly process. At present, there is a lack of equipment that can directly evaluate the iron loss of the core after the core is assembled and before the winding is installed, which makes it impossible to detect and correct potential defects in the assembly process in time. To solve the above problems, some studies have attempted to evaluate the iron loss by testing the core alone, such as using a single-phase excitation coil and a power analyzer to measure the iron loss value of the core. However, these methods still have limitations in practical applications. The test device is usually large in size and complicated to operate, which is not conducive to widespread application in production lines. In addition, the magnetic field distribution of the test environment may not accurately simulate the magnetic flux distribution of the core in the actual operation of the motor, resulting in large deviations in the test results.

[0005] Therefore, there is an urgent need to develop a testing device that can quickly and accurately evaluate the iron loss after the core is assembled. The device should be convenient, accurate and efficient, and be able to simulate the magnetic flux distribution of the core during actual operation of the motor. It can be quickly deployed on the production line and perform real-time evaluation of the assembly quality, thereby improving the control level of the stator core assembly quality and reducing the motor production cost. Summary of the invention

[0006] The technical problem to be solved by the present invention is: how to quickly and accurately evaluate the iron loss performance after the motor core is assembled to ensure the assembly quality, and simulate the magnetic flux distribution during actual operation to achieve efficient testing of the stator core loss. In the prior art, the core loss test method generally has the problems of low test efficiency, insufficient accuracy or failure to reflect the actual working conditions, which makes it difficult to meet the needs of rapid deployment and real-time monitoring of the production line.

[0007] The present invention aims to overcome the above-mentioned technical defects and provide a core loss testing device and method which is easy to operate, accurate in results and suitable for production lines, so as to improve the control level of core assembly quality, optimize the overall performance of the motor and reduce production costs.

[0008] The present invention is implemented through the following technical solutions:

[0009] A core loss tester device is designed, characterized in that the core loss tester device is composed of a rotor core, an annular armature winding, a bolt and nut device, and a base. The rotor core is made of an amorphous alloy material with low core loss, and is formed by a number of identical annular amorphous alloy laminations with teeth evenly arranged inside and axially stacked and fastened in the same state. The slit grooves formed by the teeth and the yoke are used to wind the annular armature winding. A number of mounting holes are evenly arranged on the yoke and the base of the rotor core, and the rotor core is fixed to the base by the bolt and nut device;

[0010] Each annular armature winding wound along the yoke in each slit slot has two end connecting wires. By changing the connection method of the connecting wires at both ends of the annular winding in each slit slot, a rotating magnetic field with any number of poles can be configured as needed, which can highly flexibly simulate various magnetic flux distributions in the AC motor.

[0011] Furthermore, an iron loss test device for evaluating the assembly quality of a stator core is designed, wherein the test device comprises a stator bracket, a stator core, and the core loss tester device as described above; the stator bracket is an adjustable bracket, the stator core is fixedly mounted on the stator bracket, and the position of the stator core can be adjusted by adjusting the stator bracket;

[0012] The stator core is sleeved on the outer periphery of the core loss tester device with a certain air gap between the two. The air gap between the stator core and the core loss tester device is adjusted by adjusting the position of the bracket to ensure uniform air gap on all sides. When the annular armature winding of the core loss tester is excited by a voltage source, a rotating magnetic field is generated, which is similar to the air gap magnetic field in the AC motor, so that the actual iron loss in the motor core can be estimated more realistically. The axial length of the stator core is the same as the axial length of the rotor core of the core loss tester, so as to avoid a large amount of end eddy current loss and improve the test accuracy of iron loss.

[0013] The teeth and yokes of the rotor core and the stator core are both wound with a measuring coil with a certain number of turns. The induced electromotive force waveform at each position can be obtained by connecting an oscilloscope, so as to obtain the real-time magnetic flux density change at each position and calculate the core loss under the corresponding magnetic flux density; the core loss is calculated by the difference between the input power and the copper loss of the annular armature winding. The annular armature winding is connected to an oscilloscope and a current probe to obtain the voltage value at both ends of the annular armature winding and the current value flowing through it, so as to calculate the input power; a thermocouple is arranged on the annular armature winding to obtain the actual wire temperature, correct the resistance value at the actual temperature, and calculate the actual copper loss considering the temperature effect with the current value obtained by the current probe, so as to improve the measurement accuracy of the core loss;

[0014] The iron loss testing device tests the total core loss of the motor. The proportion of the actual stator core loss to the total core loss is obtained from the finite element simulation calculation result. The stator core loss, the rotor core loss and the total core loss can be obtained through finite element calculation. The product of the proportion of the stator core loss calculated by the finite element to the total core loss and the experimental total core loss obtained by the iron loss testing device is the actual stator core loss, thereby evaluating the quality and effect of the stator core assembly.

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

[0016] 1. The annular armature winding is wound on the yoke of the rotor core, and various excitation modes are provided by changing the connection method of the annular armature winding terminals to adapt to different pole numbers, phases and pole pitch configurations. This method effectively solves the problem of the need to redistribute the winding when the integrated winding achieves different pole numbers, thereby improving work efficiency. At the same time, the annular armature winding has the advantage of high copper wire utilization, especially in low pole number configurations, where the use of distributed windings requires a larger end winding length. Therefore, the use of annular armature windings in the case of a low pole number effectively improves the utilization of copper.

[0017] 2. The stator core is mounted on the periphery of the core loss tester device. When the annular armature winding is excited, a rotating magnetic field is established, which is similar to the air gap magnetic field in the AC motor, so that the actual iron loss in the motor core can be estimated more realistically. In addition, the iron loss test device of the present invention can quickly and accurately evaluate the iron loss after the stator core is assembled. The device is convenient, accurate and efficient, and can simulate the magnetic flux distribution of the core in the actual operation of the motor. It can be quickly deployed on the production line and the assembly quality can be evaluated in real time, thereby improving the control level of the stator core assembly quality, reducing the motor production cost, and providing a certain reference value for the prediction of the iron loss of the stator core with the same process and size. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 Shown is a schematic diagram of the motor structure of this embodiment;

[0020] Figure 2 Shown is a schematic diagram of the stator core structure and test coil of this embodiment;

[0021] Figure 3 Shown is a schematic diagram of the rotor core structure and the test coil of this embodiment;

[0022] Figure 4 The figure shows a schematic diagram of the structure of the bolt and nut device used in the core loss tester device of this embodiment;

[0023] Figure 5 The figure shows the structure diagram of the core loss tester device of this embodiment;

[0024] Figure 6 FIG. 1 is a schematic structural diagram of an embodiment of an iron loss testing device for evaluating the assembly quality of a stator core according to the present invention;

[0025] Figure 7 The figure shows a schematic diagram of the connection mode of the two ends of the annular armature winding used in the core loss tester device of this embodiment;

[0026] Figure 8 The figure shows the distribution diagram of the magnetic lines of force of the motor of this embodiment;

[0027] Fig. 9 The figure shows the magnetic flux density variation diagram of the stator core tooth portion (curve A) and the rotor core tooth portion (curve B) of this embodiment;

[0028] Fig.10 It is a schematic diagram showing the comparison of the core loss of the amorphous alloy stator core after wire cutting (curve C) and the amorphous alloy stator core after stamping (curve D) in this embodiment;

[0029] Description of the drawings: 1. stator bracket; 2. base; 3. bolt and nut device; 4. stator core; 5. rotor core; 6. annular armature winding; 7. test coil. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be fully described below with reference to the accompanying drawings and specific implementation methods to provide clear and specific guidance and reference for those skilled in the art to implement the relevant technical solutions, but this is not intended to limit the scope of protection of the present application.

[0031] The present invention is directed to a core loss tester device, characterized in that the core loss tester device is composed of a rotor core, an annular armature winding, a bolt and nut device, and a base. The rotor core is made of an amorphous alloy material with low core loss, and is formed by a plurality of identical annular amorphous alloy laminations uniformly provided with teeth inside and fastened axially in the same state. The slit grooves formed by the teeth and the yoke are used to wind the annular armature winding. The yoke and the base of the rotor core are uniformly provided with a plurality of mounting holes, and the rotor core is fixed to the base by the bolt and nut device.

[0032] Each annular armature winding wound along the yoke in each slit slot has two end connecting wires. By changing the connection method of the connecting wires at both ends of the annular winding in each slit slot, a rotating magnetic field with any number of poles can be configured as needed, which can highly flexibly simulate various magnetic flux distributions in the AC motor.

[0033] Furthermore, the present invention is directed to an iron loss test device for evaluating the assembly quality of a stator core, characterized in that the test device comprises a stator bracket, a stator core, and the core loss tester device as described above; the stator bracket is an adjustable bracket, the stator core is fixedly mounted on the stator bracket, and the position of the stator core can be adjusted by adjusting the stator bracket;

[0034] The stator core is sleeved on the outer periphery of the core loss tester device with a certain air gap between the two. The air gap between the stator core and the core loss tester device is adjusted by adjusting the position of the bracket to ensure uniform air gap on all sides, and the air gap is 0.1mm. When the annular armature winding of the core loss tester is excited by a voltage source, a rotating magnetic field is generated, which is similar to the air gap magnetic field in the AC motor, so that the actual iron loss in the motor core can be estimated more realistically. The axial length of the stator core is the same as the axial length of the rotor core of the core loss tester, so as to avoid a large amount of end eddy current loss and improve the test accuracy of iron loss.

[0035] The teeth and yokes of the rotor core and the stator core are both wound with a measuring coil with a certain number of turns. By connecting an oscilloscope, the induced electromotive force waveform at each position can be obtained, thereby obtaining the real-time magnetic flux density change at each position and calculating the core loss under the corresponding magnetic flux density; the core loss is calculated by the difference between the input power and the copper loss of the annular armature winding. The annular armature winding is connected to an oscilloscope and a current probe to obtain the voltage value at both ends of the annular armature winding and the current value flowing through it, thereby calculating the input power; a thermocouple is configured on the annular armature winding to obtain the actual wire temperature, correct the resistance value at the actual temperature, and calculate the actual copper loss considering the temperature effect with the current value obtained by the current probe, thereby improving the measurement accuracy of the core loss.

[0036] Specifically, the rotor core is made of amorphous alloy material. First, the amorphous alloy strip is placed in a mold container, part of the sample is heat treated, and then placed in a vacuum impregnation device for 12 hours. The amorphous alloy strip is pressed according to the required stacking rate and sent to a furnace for drying and curing. Finally, the amorphous laminated block is made into a rotor core according to the required shape and size after wire cutting and pickling. The end wires at both ends of the annular winding are connected and fixed by a terminal connection row device, and one end of the annular winding in each slot is fixedly connected to the terminal connection row device, and the connection method of the other end of all the annular windings is changed to achieve configurations with different pole numbers, phases, and pole pitches.

[0037] The iron loss testing device tests the total core loss of the motor. The proportion of the actual stator core loss to the total core loss is obtained from the finite element simulation calculation result. The stator core loss, the rotor core loss and the total core loss can be obtained through finite element calculation. The product of the proportion of the stator core loss calculated by the finite element to the total core loss and the experimental total core loss obtained by the iron loss testing device is the actual stator core loss, thereby evaluating the quality and effect of the stator core assembly.

[0038] The parameters of the iron loss test device of this embodiment are shown in Table 1.

[0039] Table 1 Structural parameters of the iron loss test device

[0040]

[0041] The motor in this example is modeled and simulated using finite element simulation software. Figure 1 The stator core structure of the motor is shown in Figure 2 As shown in the figure, the stator core has two parts, which are made of amorphous alloy materials through wire cutting and stamping processes respectively, so as to compare the stator core loss after assembly with different manufacturing processes. Figure 3 As shown in the figure, there are 12 slots in total, and a ring-shaped armature winding is wound along the yoke in each slot. At the same time, winding the test coil on the stator core and the rotor core can observe the actual magnetic flux density changes inside the motor in real time. Figure 4 The bolt and nut arrangement shown above secures the rotor core to the base. Figure 5 The core loss tester device shown in the figure. The stator core to be tested is fixed on the stator bracket, and the stator core is evenly placed around the core loss tester device by adjusting the stator bracket to ensure uniform air gap, so as to obtain the following Figure 6 The embodiment shown is an iron loss testing device for evaluating the assembly quality of a stator core.

[0042] Figure 7 The figure is a schematic diagram of the connection mode of the two ends of the annular armature winding of this embodiment. In order to minimize the number of excitation sources, this embodiment selects two-phase power supply excitation. When the annular armature winding is excited by two-phase sinusoidal alternating current, the connection mode of the two ends of the annular armature winding of this embodiment will generate a rotating magnetic field with 6 poles. This magnetic field is similar to the air gap magnetic field in the AC motor, so that the actual iron loss in the motor core can be estimated more realistically. The distribution of the magnetic lines of force of the motor is shown in FIG. Figure 8 shown.

[0043] Fig. 9 The figure is a schematic diagram of the change of the magnetic flux density of the stator core teeth (curve A) and the magnetic flux density of the rotor core teeth (curve B). It can be seen that the effective values ​​of the magnetic flux density of the rotor core teeth and the stator core teeth are basically the same. As the excitation power increases, the magnetic field also increases. The real-time magnetic flux density changes at each position can be obtained, and the core loss under each corresponding magnetic density can be calculated.

[0044] Fig.10The stator core loss comparison chart after different stator cores are assembled is evaluated using an iron loss test device. It can be seen that the core loss of the amorphous alloy stator core (curve C) after wire cutting is lower than the core loss of the amorphous alloy stator core (curve D) after stamping under the same magnetic density. This is because during the manufacturing process, the wire cutting process reduces mechanical stress and edge defects and maintains the original magnetic properties of the amorphous alloy material, thereby significantly reducing the core loss.

[0045] The rotor core is wound with an annular armature winding, and various excitation modes can be provided by changing the connection method at both ends of the winding to achieve different pole number configurations, thereby improving work efficiency. Under low pole number configuration, the utilization rate of copper is significantly improved. At the same time, an air gap magnetic field similar to that in an AC motor can be established, so that the actual iron loss in the motor core can be estimated more realistically. In addition, winding the test coil on the stator core and the rotor core can simulate the flux distribution of the core during the actual operation of the motor. The iron loss test device is convenient and efficient, and can perform real-time evaluation of the assembly quality, thereby improving the control level of the stator core assembly quality and reducing the production cost of the motor.

[0046] Although the present invention is described in conjunction with specific embodiments, it should be understood that the invention can be further modified. This application is intended to cover any modification, use or change made to the present invention in general according to the present invention, including those solutions different from the disclosure herein and such as those solutions that can be applied to the basic features proposed above, such as those falling into the known or customary practices in the technical field to which the present invention belongs.

[0047] Because the present invention can be implemented in several forms without departing from the spirit of the essential features of the present invention, it should be understood that, unless specifically stated, the embodiments described above are not intended to limit the present invention, but should be broadly understood within the spirit and scope of the present invention as defined in the appended claims. The described embodiments should be considered in all respects to be illustrative only and not restrictive.

[0048] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0049] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A core loss tester device, characterized in that: The core loss tester device is composed of a rotor core, an annular armature winding, a bolt and nut device, and a base. The rotor core is made of an amorphous alloy material with low core loss. It is formed by a number of identical annular amorphous alloy laminations with teeth evenly arranged inside and axially stacked and fastened in the same state. The slit grooves formed by the teeth and the yoke are used to wind the annular armature winding. The yoke and the base of the rotor core are evenly provided with a number of mounting holes. The rotor core is fixed to the base by the bolt and nut device. Each annular armature winding wound along the yoke in each slit slot has two end connecting wires. By changing the connection method of the connecting wires at both ends of the annular winding in each slit slot, a rotating magnetic field with any number of poles can be configured as needed, which can highly flexibly simulate various magnetic flux distributions in the AC motor.

2. An iron loss testing device for evaluating the assembly quality of a stator core, characterized in that: The test device comprises a stator bracket, a stator core, and also comprises the core loss tester device as claimed in claim 1; the stator bracket is an adjustable bracket, the stator core is fixedly mounted on the stator bracket, and the position of the stator core can be adjusted by adjusting the stator bracket; The stator core is sleeved on the outer periphery of the core loss tester device with a certain air gap between the two. The air gap between the stator core and the core loss tester device is adjusted by adjusting the position of the bracket to ensure uniform air gap on all sides. When the annular armature winding of the core loss tester is excited by a voltage source, a rotating magnetic field is generated, which is similar to the air gap magnetic field in the AC motor, so that the actual iron loss in the motor core can be estimated more realistically. The axial length of the stator core is the same as the axial length of the rotor core of the core loss tester, so as to avoid a large amount of end eddy current loss and improve the test accuracy of iron loss. The teeth and yokes of the rotor core and the stator core are both wound with a measuring coil with a certain number of turns. The induced electromotive force waveform at each position can be obtained by connecting an oscilloscope, so as to obtain the real-time magnetic flux density change at each position and calculate the core loss under the corresponding magnetic flux density; the core loss is calculated by the difference between the input power and the copper loss of the annular armature winding. The annular armature winding is connected to an oscilloscope and a current probe to obtain the voltage value at both ends of the annular armature winding and the current value flowing through it, so as to calculate the input power; a thermocouple is arranged on the annular armature winding to obtain the actual wire temperature, correct the resistance value at the actual temperature, and calculate the actual copper loss considering the temperature effect with the current value obtained by the current probe, so as to improve the measurement accuracy of the core loss; The iron loss testing device tests the total core loss of the motor. The proportion of the actual stator core loss to the total core loss is obtained from the finite element simulation calculation result. The stator core loss, the rotor core loss and the total core loss can be obtained through finite element calculation. The product of the proportion of the stator core loss calculated by the finite element to the total core loss and the experimental total core loss obtained by the iron loss testing device is the actual stator core loss, thereby evaluating the quality and effect of the stator core assembly.

3. The iron loss testing device for evaluating the assembly quality of a stator core according to claim 2, characterized in that: The air gap between the stator core and the rotor core is less than 0.2mm.

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