A magnetic reluctance resolver and a rotor profile design method thereof

Abstract

The application relates to the technical field of reluctance rotary transformers, in particular to a reluctance rotary transformer and a rotor profile design method thereof, which comprises a stator and a rotor, eight stator teeth with the same parameters are arranged on the inner wall of the stator; a stator tooth winding is further arranged on the stator, the profile vector radius of the rotor is r(ptheta), r(ptheta)=r1+lambda-l(ptheta), wherein r1 is the base circle radius of the salient pole rotor, lambda is the distance from the inner surface of the stator tooth pole shoe to the base circle of the rotor, l(ptheta) is the air gap length between the inner surface of the stator tooth pole shoe and the rotor; wherein p is the pole pair number of the rotor, theta is the mechanical rotation angle of the rotor, A is the inner surface area of the stator tooth pole shoe, mu0 is the air permeability, I m is the coil excitation current, N is the excitation winding number, phi m is the average magnetic flux, and delta is the amplitude modulation coefficient. In the case that the shape of the stator is determined, the rotor profile is designed through air gap change, so that the harmonic content of the output signal of the reluctance rotary transformer can be well reduced.

Description

Technical Field

[0001] This invention relates to the field of reluctance rotary transformer technology, and more particularly to a reluctance rotary transformer and its rotor profile design method. Background Technology

[0002] With the development of industrial equipment such as electric vehicles and high-precision machine tools, the accuracy requirements for drive systems are also increasing, especially for sensors used to detect rotor position in motor servo systems.

[0003] A reluctance rotary transformer is essentially a controllable motor. Its output signal and rotor position satisfy a certain functional relationship. After decoupling the output voltage, the rotor position information can be obtained, which is equivalent to a sensor used to detect the rotor position. Reluctance rotary transformers can provide higher precision rotor position information. Because of their small size, simple structure, and adaptability to various harsh working environments, reluctance rotary transformers are suitable for use in various complex working conditions.

[0004] The rotor of a reluctance rotary transformer employs a salient-pole structure. Its principle lies in utilizing the salient-pole effect to cause the mutual inductance between the excitation winding and the output winding to change with the rotor's position, thereby causing the output winding to output a signal in the form of a sine and cosine function containing rotor position information. In previous rotor profile designs, sine coefficients were typically used for optimization, without considering air gap variations in the rotor profile design.

[0005] In current research on reluctance rotary transformers, reducing the harmonic content of the output signal and increasing its sinusoidal intensity are major challenges. Currently, increasing the number of teeth is a common method to reduce harmonic content, but this introduces significant difficulties into the installation process. Summary of the Invention

[0006] The purpose of this invention is to provide a reluctance rotary transformer and its rotor profile design method to solve the problems of reducing the harmonic content of the output signal of the rotary transformer and the installation process problems caused by the large number of teeth in the existing technology.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A reluctance rotary transformer includes a stator and a rotor. The stator has eight identical stator teeth on its inner wall: tooth one, tooth two, tooth three, tooth four, tooth five, tooth six, tooth seven, and tooth eight. The central angle formed by the center lines of tooth one and tooth two, and tooth three and tooth four, is 1.5π / p. The center lines of tooth one and tooth five are collinear, as are the center lines of tooth two and tooth six, tooth three and tooth seven, and tooth four and tooth eight. The stator also has stator tooth windings. The rotor's profile radius vector is r(pθ), r(pθ) = r1 + λ - l(pθ), where r1 is the base circle radius of the salient pole rotor, λ is the distance from the inner surface of the stator tooth pole shoe to the rotor base circle, and l(pθ) is the length of the air gap between the inner surface of the stator tooth pole shoe and the rotor. Where p is the number of rotor pole pairs, θ is the rotor mechanical rotation angle, A is the inner surface area of ​​the stator pole shoe, μ0 is the air permeability, and I m The current is the magnetizing current of the coil, N is the number of turns in the magnetizing winding, and φ is the magnetizing current. m denoted as the average magnetic flux and Δ as the amplitude modulation coefficient.

[0009] Furthermore, the rotor profile is drawn from the rotor's profile radius vector.

[0010] Furthermore, the rotor profile is salient-pole shaped, and the number of salient poles is the same as the number of pole pairs.

[0011] Furthermore, the length of the air gap between the inner surface of the stator pole shoe and the rotor changes with the rotor angle, and the amount of change follows the trend of a secant function curve; the sum of the lengths of the two air gap segments between the inner surfaces of the two stator pole shoes and the rotor at different positions under the same magnetic flux circuit also follows the trend of a secant function curve.

[0012] Furthermore, the stator is made of stacked silicon steel sheets.

[0013] Furthermore, the stator tooth winding is an equal-turn winding, which includes an excitation winding and a signal output winding. The excitation winding is wound on the inner layer of the stator tooth, and the signal output winding is wound on the outer layer of the stator tooth. The signal output winding includes a sine signal output winding and a cosine signal output winding.

[0014] Furthermore, the excitation winding is wound in the forward direction on teeth one, two, five, and six, and in the reverse direction on teeth three, four, seven, and eight; the sine signal output winding is wound in the forward direction on teeth one, two, and six, and in the reverse direction on tooth five; the cosine signal output winding is wound in the reverse direction on teeth three, seven, and eight, and in the forward direction on tooth four.

[0015] Furthermore, the rotor pole pair number p = 9.

[0016] Furthermore, the output waveforms of the sine signal output winding and the cosine signal output winding always maintain a phase difference of 90° electrical angle.

[0017] A method for designing the rotor profile of a reluctance rotary transformer, wherein the rotor profile radius is r(pθ), and the rotor profile is designed using the formula r(pθ)=r1+λ-l(pθ), where r1 is the base circle radius of the salient pole rotor, λ is the distance from the inner surface of the stator pole shoe to the base circle of the rotor, and l(pθ) is the length of the air gap between the inner surface of the stator pole shoe and the rotor. Where p is the number of rotor pole pairs, θ is the rotor mechanical rotation angle, A is the inner surface area of ​​the stator pole shoe, μ0 is the air permeability, and I m The current is the magnetizing current of the coil, N is the number of turns in the magnetizing winding, and φ is the magnetizing current. m denoted as the average magnetic flux and Δ as the amplitude modulation coefficient.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] Compared with conventional rotor profiles, the rotor profile in this invention improves the output accuracy of the reluctance rotary transformer and significantly reduces the harmonic content. At the same time, it eliminates the need to increase the number of teeth to reduce the harmonic content, thus reducing the difficulty of the installation process. Attached Figure Description

[0020] Figure 1 This is a structural view of the present invention;

[0021] Figure 2 This is a schematic diagram of the stator dimensions in Embodiment 2 of the present invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Example 1

[0024] See Figure 1 As shown, a reluctance rotary transformer is characterized by comprising: a stator and a rotor. The inner wall of the stator is provided with eight stator teeth with identical parameters: tooth one, tooth two, tooth three, tooth four, tooth five, tooth six, tooth seven, and tooth eight. The central angle formed by the center lines of tooth one and tooth two, and tooth three and tooth four, is 1.5π / p. The center lines of tooth one and tooth five are collinear, as are the center lines of tooth two and tooth six, tooth three and tooth seven, and tooth four and tooth eight. The stator is also provided with stator tooth windings. The rotor's profile radius vector is r(pθ), r(pθ) = r1 + λ - l(pθ), where r1 is the base circle radius of the salient pole rotor, λ is the distance from the inner surface of the stator tooth pole shoe to the rotor base circle, and l(pθ) is the length of the air gap between the inner surface of the stator tooth pole shoe and the rotor. Where p is the number of rotor pole pairs, θ is the rotor mechanical rotation angle, A is the inner surface area of ​​the stator pole shoe, μ0 is the air permeability, and I m The current is the magnetizing current of the coil, N is the number of turns in the magnetizing winding, and φ is the magnetizing current. m Δ is the average magnetic flux and Δ is the amplitude modulation coefficient.

[0025] The rotor profile is drawn from the rotor profile radius vector; the rotor profile is salient pole shaped, the number of rotor salient poles is the same as the number of rotor pole pairs, and the number of rotor pole pairs p = 9.

[0026] The length of the air gap between the inner surface of the stator pole shoe and the rotor changes with the rotor angle, and the change follows a secant function curve. The sum of the lengths of the two air gap segments between the inner surfaces of the stator pole shoes and the rotor at different positions in the same magnetic flux circuit also follows a secant function curve. Since the air gap changes with a secant curve, the magnetic flux changes with a sine curve. The stator is made of stacked silicon steel sheets.

[0027] The stator tooth winding is an equal-turn winding, which includes an excitation winding and a signal output winding. The excitation winding is wound in the inner layer of the stator tooth, and the signal output winding is wound in the outer layer of the stator tooth. The signal output winding includes a sine signal output winding and a cosine signal output winding.

[0028] The excitation winding is wound in the forward direction on teeth 1, 2, 5 and 6, and in the reverse direction on teeth 3, 4, 7 and 8; the sine signal output winding is wound in the forward direction on teeth 1, 2 and 6, and in the reverse direction on tooth 5; the cosine signal output winding is wound in the reverse direction on teeth 3, 7 and 8, and in the forward direction on tooth 4.

[0029] The output waveforms of the sine signal output winding and the cosine signal output winding always maintain a phase difference of 90° electrical angle.

[0030] A rotor profile design method for a reluctance rotary transformer, wherein the rotor profile radius vector is r(pθ), and the rotor profile is designed using the formula r(pθ)=r1+λ-l(pθ), where r1 is the base circle radius of the salient pole rotor, λ is the distance from the inner surface of the stator pole shoe to the rotor base circle, and l(pθ) is the air gap length between the inner surface of the stator pole shoe and the rotor. Where p is the number of rotor pole pairs, θ is the rotor mechanical rotation angle, A is the inner surface area of ​​the stator pole shoe, μ0 is the air permeability, and I m The current is the magnetizing current of the coil, N is the number of turns in the magnetizing winding, and φ is the magnetizing current. m denoted as the average magnetic flux and Δ as the amplitude modulation coefficient.

[0031] Example 2

[0032] See Figures 1-2 As shown, In the formula, Δ is taken as 0.5 to determine the rotor profile. Below is a comparison table of harmonic proportions between simulation experiments and existing technologies:

[0033]

[0034] The table above shows that, given a fixed stator shape, this invention can effectively reduce the harmonic content of the output signal of a reluctance rotary transformer by designing the rotor profile through changes in the air gap. At the same time, it eliminates the need to increase the number of stator teeth, thus reducing the difficulty of the installation process.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A reluctance rotary transformer, characterized in that, include: The stator and rotor, wherein the inner wall of the stator is provided with eight stator teeth with identical parameters: tooth one, tooth two, tooth three, tooth four, tooth five, tooth six, tooth seven, and tooth eight, wherein the central angle formed by the center line of tooth one and the center line of tooth two, and the central angle formed by the center line of tooth three and the center line of tooth four are all... Tooth 1 and tooth 5 have collinear center lines, tooth 2 and tooth 6 have collinear center lines, tooth 3 and tooth 7 have collinear center lines, and tooth 4 and tooth 8 have collinear center lines; the stator is also provided with stator tooth windings, and the rotor's profile radius vector is... , ,in, Let be the base circle radius of the salient pole rotor. This is the distance from the inner surface of the stator pole shoe to the rotor base circle. This is the length of the air gap between the inner surface of the stator pole shoe and the rotor. ,in, The number of rotor pole pairs, For the rotor mechanical rotation angle, This represents the inner surface area of ​​the stator tooth pole shoe. air permeability, The excitation current of the coil, This refers to the number of turns in the excitation winding. The average magnetic flux, This is the amplitude modulation factor; The rotor profile is salient-pole shaped, and the number of salient poles of the rotor is the same as the number of pole pairs of the rotor. The length of the air gap between the inner surface of the stator tooth pole shoe and the rotor changes with the rotor rotation angle, and the amount of change follows the trend of a secant function curve. The sum of the lengths of the two air gaps between the inner surfaces of the stator tooth pole shoes and the rotor at different positions under the same magnetic flux circuit also follows the trend of a secant function curve.

2. A reluctance rotary transformer according to claim 1, characterized in that: The rotor profile is drawn from the rotor profile vector.

3. A reluctance rotary transformer according to claim 2, characterized in that: The rotor profile is salient-pole shaped, and the number of salient poles is the same as the number of pole pairs.

4. A reluctance rotary transformer according to claim 1, characterized in that: The length of the air gap between the inner surface of the stator pole shoe and the rotor changes with the rotor angle, and the change shows a trend of secant function curve; the change of the sum of the lengths of the two air gap segments between the inner surfaces of the two stator pole shoes and the rotor at different positions under the same magnetic flux circuit also shows a trend of secant function curve.

5. A reluctance rotary transformer according to claim 1, characterized in that: The stator is made of stacked silicon steel sheets.

6. A reluctance rotary transformer according to claim 1, characterized in that: The stator tooth winding is an equal-turn winding, which includes an excitation winding and a signal output winding. The excitation winding is wound in the inner layer of the stator, and the signal output winding is wound in the outer layer of the stator. The signal output winding includes a sine signal output winding and a cosine signal output winding.

7. A reluctance rotary transformer according to claim 6, characterized in that: The excitation winding is wound in the forward direction on teeth 1, 2, 5 and 6, and in the reverse direction on teeth 3, 4, 7 and 8; the sine signal output winding is wound in the forward direction on teeth 1, 2 and 6, and in the reverse direction on tooth 5; the cosine signal output winding is wound in the reverse direction on teeth 3, 7 and 8, and in the forward direction on tooth 4.

8. A reluctance rotary transformer according to claim 7, characterized in that: The output waveforms of the sine signal output winding and the cosine signal output winding always maintain a phase difference of 90° electrical angle.

9. A rotor profile design method for a reluctance rotary transformer as described in claim 1, characterized in that: The rotor's profile radius vector is Using formula Design the rotor profile, where, Let be the base circle radius of the salient pole rotor. This is the distance from the inner surface of the stator pole shoe to the rotor base circle. This is the length of the air gap between the inner surface of the stator pole shoe and the rotor. ,in, The number of rotor pole pairs, For the rotor mechanical rotation angle, This represents the inner surface area of ​​the stator tooth pole shoe. air permeability, The excitation current of the coil, This refers to the number of turns in the excitation winding. The average magnetic flux. This is the amplitude modulation coefficient.

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