Experimental method for separating magnetization and loss of tooth part and yoke part of stator slotted iron core

Abstract

The invention discloses an experimental method for separating stator slotted core tooth part yoke part magnetization and loss, which comprises the following steps of: firstly, winding a primary / secondary side winding on a stator yoke part, testing to obtain the loss and magnetization curve of the yoke part according to the basic principle of a transformer, and then stacking two same stator teeth in a tooth-to-tooth manner to obtain the loss and magnetization curve of the yoke part. Primary / secondary side coils are placed at the same position teeth of an upper stator and a lower stator, a magnetization and loss curve of a tooth part is obtained through testing, the magnetization and loss curve of a yoke part and the magnetization curve of the tooth part are input into a finite element, magnetic pressure drop and loss of the yoke part are solved, yoke part related data are removed from the experiment data of the magnetization and loss curve of the tooth part, and the magnetic pressure drop and loss of the yoke part are calculated. According to the stator slotted core tooth part / yoke part magnetization and loss separation experiment method provided by the invention, the magnetization and loss curve of the tooth part can be directly measured, and the deterioration influence of slotting on the tooth part can be quantitatively analyzed.

Description

Technical Field

[0001] The invention relates to the technical field of magnetization and loss testing of a motor stator core, and in particular to an experimental method for separating magnetization and loss of a tooth part and yoke part of a stator slotted core. Background Art

[0002] At present, there are two main experimental methods for testing the magnetization and loss curves of ferromagnetic material strips, unslotted toroidal cores, and toroidal cores of different widths: the Epstein square ring method and the toroidal core test method based on the transformer principle. There is no experimental method to directly test the magnetization and loss performance of the slotted stator core teeth of the motor, and it is impossible to directly qualitatively and quantitatively analyze the deterioration effect of slotting on the teeth.

[0003] The existing Epstein square circle test method can only test the magnetization and loss curves of a single piece of ferromagnetic material strip. However, the strip needs a series of processing before it can be made into a stator core, such as lamination or winding, annealing, paint dipping and curing, slotting, etc. Each processing technology will bring additional deterioration of the magnetic properties of the core and increase in loss. The Epstein square circle method cannot take into account the additional deterioration of the core.

[0004] For the unslotted toroidal core, the core test method is a toroidal core test method based on the transformer principle, which measures the input current and input power of the primary winding, measures the induced voltage of the secondary winding, and obtains the magnetization and loss curves of the unslotted toroidal core. Because the toroidal core needs to be slotted during actual motor processing, this test method cannot consider the additional impact of slotting on the magnetic properties and losses of the core.

[0005] In addition, the annular core is processed into special-shaped parts with different widths to simulate the situation of motor slotting. This test method is an annular core experimental method based on the transformer principle, but the special-shaped parts and experimental test method have limitations. Because the magnetic circuit of the core in its experimental test runs through the equivalent tooth and yoke, it is still impossible to separate the magnetization and loss curves of the equivalent tooth and yoke.

[0006] Therefore, the prior art still needs to be improved and enhanced. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide an experimental method for separating the magnetization and loss of the tooth and yoke of a stator slotted core, and quantitatively analyzing the deterioration effect of slotting on the tooth.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: An experimental method for separating magnetization and loss of a stator slot core tooth / yoke, comprising: Step 1: Wind the primary winding and the secondary winding on the stator yoke respectively, and obtain the loss and magnetization curve of the yoke according to the basic principle of the transformer; Step 2, stack two identical stator teeth together, place primary or secondary coils on the same position teeth of the upper and lower stators, and test to obtain magnetization and loss curves of the teeth with partial yoke magnetic circuit; Step 3. Input the magnetization and loss curve of the yoke and the magnetization curve of the tooth with partial yoke magnetic circuit into the finite element method to calculate the magnetic pressure drop and loss of the yoke. Remove the data related to the partial yoke magnetic circuit from the experimental data of the magnetization and loss curve of the tooth with partial yoke magnetic circuit to obtain the magnetization and loss curve of the tooth.

[0009] Furthermore, in step 1, the primary winding is firstly wound around the stator yoke, the input voltage, current and power of the primary winding are recorded, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit.

[0010] Furthermore, in step 1, the secondary winding is wound around the stator yoke, and the induced voltage on the secondary side is recorded. According to the relationship between the induced voltage, frequency, number of turns, magnetic flux density and cross-sectional area of ​​the magnetic circuit: E = 4.44fN2BS; Where, E is the back EMF on the secondary side, f is the frequency, N2 is the number of turns of the secondary coil, B is the magnetic flux density, and S is the cross-sectional area of ​​the yoke magnetic circuit; The BH magnetization curve of the yoke is obtained by testing. The core loss values ​​of different magnetic flux densities B are obtained by subtracting the copper loss of the primary winding from the input loss of the primary winding, thereby obtaining the BP loss curve of the yoke.

[0011] Furthermore, in step 2, the coil on the primary side is wound around two adjacent teeth of a stator, and the arrangement is the first slot in, the second slot out, the third slot in, the second slot out, and the winding arrangement order of the second stator is the same as that of the first stator. The two stator teeth are stacked together, the windings are placed symmetrically, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit. The magnetic circuit length is the height of 4 teeth and the yoke length of 2 adjacent teeth. The cross-sectional area is the area of ​​a single tooth top surface. The magnetization and loss curves of the teeth with partial yoke magnetic circuit are obtained when two identical stator teeth are stacked on each other.

[0012] Furthermore, in step 3, a finite element method is used to remove the magnetic pressure drop H*L and loss of part of the yoke in the tooth experiment to obtain the magnetization and loss curve of the tooth, and the magnetization and loss curve of the yoke and the magnetization curve of the tooth with a partial yoke magnetic circuit are input into a three-dimensional finite element, and the current of the experimental test is substituted into a finite element model of two stator teeth stacked on each other to obtain the yoke magnetic pressure drop and yoke loss under different excitation conditions, and the tooth magnetization and loss curve with a partial yoke magnetic circuit obtained by post-experimental processing is subtracted from the yoke magnetic pressure drop and yoke loss under different excitation conditions obtained by finite element simulation, and finally the magnetization and loss curves of the tooth under different excitations are obtained.

[0013] The technical solution adopted by the present invention has the following beneficial effects: An experimental method for separating magnetization and loss of the teeth / yoke of a stator slotted core is provided in an embodiment of the present invention. The experimental method can directly measure the magnetization and loss curves of the teeth and quantitatively analyze the deterioration effect of slotting on the teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The yoke magnetization and loss curve test method, where 1 is the stator tooth; 2 is the primary side excitation coil, 3 is the stator yoke, and 4 is the secondary side induced voltage coil; Figure 2 A test method for measuring magnetization and loss curves of a tooth portion (with a partial yoke magnetic circuit) when two stator teeth are stacked on each other, wherein 5 is a primary side excitation coil, 6 is a secondary side induced voltage coil, 7 is a stator tooth portion, and 8 is a stator yoke portion; Figure 3 This is the magnetic flux distribution diagram of the gear experiment; Figure 4 This is a comparison diagram of the magnetization curves of the tooth and yoke strips; Figure 5 This is a comparison diagram of the loss curves of the tooth and yoke; Figure 6 The invention is a method for testing the yoke of a stacked slotted radial stator core, wherein 9 is the stator core, 10 is the primary side excitation coil, and 11 is the secondary side induction voltage coil; Figure 7 The invention discloses a method for testing the teeth of a stacked slotted radial stator core, wherein 9 is the stator core, 10 is the primary side excitation coil, and 11 is the secondary side induction voltage coil. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] An experimental method for separating magnetization and loss of a stator slot core tooth / yoke, comprising: Step 1: Wind the primary winding and the secondary winding on the stator yoke respectively, and according to the basic principle of transformer, test and obtain the loss and magnetization curve of the yoke; Figure 1 As shown, different excitation currents are passed through the primary coil, the current voltage and input power are recorded, and the induced electromotive force is recorded in the secondary winding. According to the transformer principle, the magnetization curve of the yoke is obtained by post-processing. The copper loss is removed from the primary input power to obtain the loss curve of the yoke. In step 1, the primary winding is first wound around the stator yoke, the input voltage, current and power of the primary winding are recorded, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit.

[0017] Furthermore, in step 1, the secondary winding is wound around the stator yoke, and the induced voltage on the secondary side is recorded. According to the relationship between the induced voltage, frequency, number of turns, magnetic flux density and cross-sectional area of ​​the magnetic circuit: E = 4.44fN2BS; Where, E is the back EMF on the secondary side, f is the frequency, N2 is the number of turns of the secondary coil, B is the magnetic flux density, and S is the cross-sectional area of ​​the yoke magnetic circuit; The BH magnetization curve of the yoke is obtained by testing. The core loss values ​​of different magnetic flux densities B are obtained by subtracting the copper loss of the primary winding from the input loss of the primary winding, thereby obtaining the BP loss curve of the yoke.

[0018] Step 2: Figure 6 and Figure 7 As shown, two identical stator teeth are stacked together, and primary or secondary coils are placed on the same position teeth of the upper and lower stators. The magnetization and loss curves of the yoke and the tooth with partial yoke magnetic circuit are obtained respectively; In step 2, the test method can perform a tooth yoke separation test on the wound and stacked slotted stator core. As long as two identical stator teeth are stacked together without any additional air gap, the test requirements can be met.

[0019] In step 2, the primary coil is wound around two adjacent teeth of a stator, and the arrangement is the first slot in, the second slot out, the third slot in, the second slot out. The winding arrangement order of the second stator is the same as that of the first stator. The two stator teeth are stacked together, the windings are placed symmetrically, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit. The magnetic circuit length is the height of 4 teeth and the yoke length of 2 adjacent teeth. The cross-sectional area is the area of ​​a single tooth top surface. The magnetization and loss curves of the teeth with partial yoke magnetic circuit are obtained when two identical stator teeth are stacked on each other.

[0020] Step 3: Input the magnetization and loss curve of the yoke and the magnetization curve of the tooth with a partial yoke magnetic circuit into the finite element method to calculate the magnetic pressure drop and loss of the yoke, remove the data related to the partial yoke magnetic circuit from the experimental data of the magnetization and loss curve of the tooth with a partial yoke magnetic circuit, and obtain the magnetization and loss curve of the tooth; Figure 2 As shown in the figure, when the coils are arranged as shown in the figure, the magnetic field generated by the primary winding is only in the upper and lower four teeth and part of the yoke. The magnetization and loss of the teeth (including part of the yoke magnetic circuit) and the yoke are brought into the finite element, and the magnetic density distribution is shown as follows Figure 3 As shown, it can be seen that the magnetic flux density is mainly distributed on the four teeth wound by the coil and the yoke. Therefore, it is necessary to separate the magnetization and loss effects of the magnetic circuit of the yoke and obtain the magnetization and loss curves of the teeth. The magnetization and loss curves of the teeth and yoke are compared. Figure 4 , as shown in 5.

[0021] Furthermore, in step 3, a finite element method is used to remove the magnetic pressure drop H*L and loss of part of the yoke in the tooth experiment to obtain the magnetization and loss curve of the tooth, and the magnetization and loss curve of the yoke and the magnetization curve of the tooth with a partial yoke magnetic circuit are input into a three-dimensional finite element, and the current of the experimental test is substituted into a finite element model of two stator teeth stacked on each other to obtain the yoke magnetic pressure drop and yoke loss under different excitation conditions, and the tooth magnetization and loss curve with a partial yoke magnetic circuit obtained by post-experimental processing is subtracted from the yoke magnetic pressure drop and yoke loss under different excitation conditions obtained by finite element simulation, and finally the magnetization and loss curves of the tooth under different excitations are obtained.

[0022] like Figure 2 As shown, when the coils are arranged as follows, the magnetic field generated by the primary winding is only in the upper and lower four teeth and part of the yoke. The magnetization and loss of the teeth (including part of the yoke magnetic circuit) and the yoke are brought into the finite element, and the magnetic density distribution is shown as follows Figure 3 As shown, it can be seen that the magnetic flux density is mainly distributed on the four teeth around which the coil is wound and on the yoke. Therefore, it is necessary to separate the magnetization and loss effects of part of the yoke magnetic circuit to obtain the magnetization and loss curves of the teeth.

[0023] In addition, in an embodiment of the present invention, the test method is also applicable to stacked slotted radial stator cores, the yoke test method is applied to the yoke of the radial motor, and the tooth test method is applied to unfolding the radial motor into a stacked linear motor.

[0024] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the schemes disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed in this disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

Claims

1. An experimental method for separating magnetization and loss of the teeth and yoke of a stator slotted core, characterized in that: include: Step 1: Wind the primary winding and the secondary winding on the stator yoke respectively, and obtain the loss and magnetization curve of the yoke according to the basic principle of the transformer; Step 2, stack two identical stator teeth together, place primary or secondary coils on the same position teeth of the upper and lower stators, and test to obtain magnetization and loss curves of the teeth with partial yoke magnetic circuit; Step 3. Input the magnetization and loss curve of the yoke and the magnetization curve of the tooth with partial yoke magnetic circuit into the finite element method to calculate the magnetic pressure drop and loss of the yoke. Remove the data related to the partial yoke magnetic circuit from the experimental data of the magnetization and loss curve of the tooth with partial yoke magnetic circuit to obtain the magnetization and loss curve of the tooth.

2. The experimental method for magnetization and loss of the teeth and yoke of a separated stator slotted core according to claim 1, characterized in that: In step 1, the primary winding is first wound around the stator yoke, the input voltage, current and power of the primary winding are recorded, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit.

3. The experimental method for magnetization and loss of the tooth and yoke of a separated stator slotted core according to claim 1, characterized in that: In step 1, the secondary winding is wound around the stator yoke, and the induced voltage on the secondary side is recorded. According to the relationship between the induced voltage, frequency, number of turns, magnetic flux density and magnetic circuit cross-sectional area: E = 4.44fN2BS; Where, E is the back EMF on the secondary side, f is the frequency, N2 is the number of turns of the secondary coil, B is the magnetic flux density, and S is the cross-sectional area of ​​the yoke magnetic circuit; The BH magnetization curve of the yoke is obtained by testing. The core loss values ​​of different magnetic flux densities B are obtained by subtracting the copper loss of the primary winding from the input loss of the primary winding, thereby obtaining the BP loss curve of the yoke.

4. The experimental method for magnetization and loss of the teeth and yoke of a separated stator slotted core according to claim 1, characterized in that: In step 2, the coil on the primary side is wound around two adjacent teeth of a stator, and the arrangement is the first slot in, the second slot out, the third slot in, the second slot out. The winding arrangement order of the second stator is the same as that of the first stator. The two stator teeth are stacked together, the windings are placed symmetrically, and the magnetic field strength is obtained according to the following formula: H*L=I1*N1; Among them, I1 is the current on the primary side, N1 is the number of turns of the primary side coil, and L is the length of the yoke magnetic circuit. The magnetic circuit length is the height of 4 teeth and the yoke length of 2 adjacent teeth. The cross-sectional area is the area of ​​a single tooth top surface. The magnetization and loss curves of the teeth with partial yoke magnetic circuit are obtained when two identical stator teeth are stacked on each other.

5. The experimental method for magnetization and loss of the teeth and yoke of a separated stator slotted core according to claim 1, characterized in that: In the step 3, the finite element method is used to remove the magnetic pressure drop H*L and loss of part of the yoke in the tooth experiment to obtain the magnetization and loss curve of the tooth, the magnetization and loss curve of the yoke and the magnetization curve of the tooth with a partial yoke magnetic circuit are input into the three-dimensional finite element, the current of the experimental test is substituted into the finite element model of two stator teeth stacked on each other to obtain the yoke magnetic pressure drop and yoke loss under different excitation conditions, the tooth magnetization and loss curve with a partial yoke magnetic circuit obtained by post-experimental processing is subtracted from the yoke magnetic pressure drop and yoke loss under different excitation conditions obtained by finite element simulation, and finally the magnetization and loss curves of the tooth under different excitations are obtained.

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