Sine ripple outer rotor single-channel winding type rotary transformer and system

Abstract

The invention discloses a sine ripple outer rotor single-channel winding type rotary transformer and system. The transformer comprises a stator, a rotor, an excitation winding, a sine signal winding and a cosine signal winding. The rotor is sleeved outside the stator; a plurality of stator teeth are arranged on the outer portion of the stator in the circumferential direction, each stator tooth comprises an upper tooth and a lower tooth, the upper teeth and the lower teeth are arranged in the axial direction of the stator, and gaps are formed between the upper teeth and the lower teeth; the sine signal winding and the cosine signal winding are arranged on each stator tooth; the rotor is of a sine ripple structure in the axial direction, and the excitation winding is arranged on the rotor. The transformer has the advantages of being high in measurement precision and small in size.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to a sinusoidal corrugated external rotor single-channel wound rotary transformer and system. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Wound-rotor rotary transformers, used to control micromotors by providing analog signals, require a shaft-angle digital converter system to provide angular position information. The accuracy of the rotary transformer angle measurement system is determined by both the accuracy of the rotary transformer itself and the accuracy of the shaft-angle converter. It boasts advantages such as reliable structure, long lifespan, and strong anti-interference capabilities. Furthermore, it is easy to install, provides rotor position angles even when the motor is stationary, and can operate in various harsh environments including humidity, high temperature, and extreme cold.

[0004] Traditional wound-rotor rotary transformers typically employ a rotor with an excitation winding and a stator with a signal winding. The excitation winding can use a brushed input method or a coupled transformer input method to achieve current input, while the signal winding induces a sinusoidal output signal through the magnetic fields in the rotor and stator, thus achieving angle measurement. Traditional wound-rotor rotary transformers require a sinusoidal distribution of turns in the rotor winding to achieve a sinusoidal change in the air gap magnetic flux between the rotor and stator. It is difficult to achieve a dual-channel magnetic circuit structure. The difficulty lies in the fact that a dual-channel magnetic circuit requires the synthesis of sinusoidal functions of different frequencies. The winding exhibits an asymmetrical distribution across the entire circumference, making the winding process extremely cumbersome. Furthermore, when using traditional sinusoidal winding methods, the number of turns distributed in each rotor slot is an integer. Even if the winding process is successfully implemented, the integer turn distribution can lead to large signal output errors. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a sinusoidal corrugated external rotor single-channel wound rotary transformer and system. The transformer features a sinusoidal variation in the air gap between the rotor and stator, enabling high-precision angle measurement and a small size.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In the first aspect, a sinusoidal rippled external rotor single-channel wound rotary transformer is proposed, comprising: stator, rotor, excitation winding, sinusoidal signal winding and cosine signal winding; The rotor is fitted onto the outside of the stator; Multiple stator teeth are arranged on the outside of the stator along the circumferential direction. Each stator tooth includes an upper tooth and a lower tooth. The upper tooth and the lower tooth are arranged along the axial direction of the stator, and a gap is provided between the upper tooth and the lower tooth. Both the sine wave winding and the cosine wave winding are located on each stator tooth; The rotor has a sinusoidal corrugated structure in the axial direction, and the excitation winding is set on the rotor.

[0007] Furthermore, multiple stator teeth are evenly distributed along the circumference of the stator.

[0008] Furthermore, the rotor thickness is equal to the axial length of the upper teeth.

[0009] Furthermore, the axial length of the upper tooth, the axial length of the lower tooth, and the axial length of the gap between the upper and lower teeth are equal.

[0010] Furthermore, the rotor is aligned with the gaps between the upper and lower teeth.

[0011] Furthermore, both the sine signal winding and the cosine signal winding are wound on the stator teeth in a sinusoidal winding manner, with a phase difference of 90° electrical angle.

[0012] Furthermore, the number of turns of the sine signal winding and the cosine signal winding on each stator tooth is determined based on the amplitude of each signal and the number of stator teeth at the distance from the stator set axis.

[0013] Furthermore, an equal air gap is provided between the stator and the rotor.

[0014] Furthermore, the excitation winding adopts an equal-turn winding method and is set on the rotor.

[0015] Secondly, a sinusoidal corrugated external rotor single-channel wound rotary transformer system is proposed, including the sinusoidal corrugated external rotor single-channel wound rotary transformer proposed in the first aspect.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a sinusoidal corrugated external rotor single-channel wound rotary transformer and system. The transformer has a rotor located outside the stator, with the rotor having a sinusoidal corrugated structure in the axial direction. The excitation winding is located on the rotor, and stator teeth are located outside the stator with a gap in the middle of the stator teeth. Sinusoidal signal windings and cosine signal windings are located on the stator teeth, causing the air gap between the stator and rotor to change sinusoidally. This allows the signal windings to accurately sense sinusoidal signals for output, achieving high-precision angle measurement. Furthermore, the transformer has a small size.

[0017] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0019] Figure 1 This is a schematic diagram of a three-dimensional structure of a sinusoidal corrugated external rotor single-channel wound rotary transformer proposed in an embodiment of the present invention; Figure 2 This is a schematic diagram of a planar structure of a sinusoidal corrugated external rotor single-channel wound rotary transformer proposed in an embodiment of the present invention; Figure 3 This is a schematic diagram of the axial cross section of a sinusoidal corrugated external rotor single-channel wound rotary transformer according to an embodiment of the present invention; Figure 4 This is a diagram showing the turn distribution of the sine and cosine signal windings of a single-channel wound rotary transformer with an external rotor, as proposed in an embodiment of the present invention. Figure 5 This is a top view of the rotor structure proposed in an embodiment of the present invention; Figure 6 This is a front view of the rotor structure proposed in an embodiment of the present invention; Figure 7 This is a planar unfolded schematic diagram of the rotor proposed in an embodiment of the present invention.

[0020] Among them: 1. Rotor, 2. Stator, 3. Air gap, 4. Excitation winding, 5. Sine signal winding, 6. Cosine signal winding, 7. Stator axis, 8. Stator axis, 9. Rotor axis, 10. Rotor axis, 2-1. Upper tooth, 2-2. Stator through slot, 2-3. Lower tooth. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0025] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] Traditional wound-rotor rotary transformers typically employ a rotor with an excitation winding and a stator with a signal winding. The excitation winding can use a brushed input method or a coupled transformer input method to achieve current input, while the signal winding induces a sinusoidal output signal through the magnetic fields in the rotor and stator, thus achieving angle measurement. Traditional wound-rotor rotary transformers require a sinusoidal distribution of turns in the rotor winding to achieve a sinusoidal change in the air gap magnetic flux between the rotor and stator. It is difficult to achieve a dual-channel magnetic circuit structure. The difficulty lies in the fact that a dual-channel magnetic circuit requires the synthesis of sinusoidal functions of different frequencies. The winding exhibits an asymmetrical distribution across the entire circumference, making the winding process extremely cumbersome. Furthermore, when using traditional sinusoidal winding methods, the number of turns distributed in each rotor slot is an integer. Even if the winding process is successfully implemented, the integer turn distribution can lead to large signal output errors.

[0027] To improve the measurement accuracy of wound rotary transformers and achieve high-precision angle measurement, this invention proposes a sinusoidal corrugated external rotor single-channel wound rotary transformer, such as... Figures 1-7 As shown, it includes: stator 2, rotor 1, excitation winding 4, sine signal winding 5 and cosine signal winding 6; The rotor 1 is fitted onto the outside of the stator 2; Multiple stator teeth are arranged on the outside of the stator 2 along the circumferential direction. Each stator tooth includes an upper tooth 2-1 and a lower tooth 2-3. The upper tooth 2-1 and the lower tooth 2-3 are arranged along the axial direction of the stator 2, and a gap is provided between the upper tooth 2-1 and the lower tooth 2-3. Both the sine signal winding 5 and the cosine signal winding 6 are mounted on each stator tooth; The rotor has a sinusoidal corrugated structure in the axial direction, and the excitation winding 4 is set on the rotor 1.

[0028] This invention proposes a sinusoidal corrugated external rotor single-channel wound rotary transformer. By placing the rotor outside the stator, the rotor has a sinusoidal corrugated structure in the axial direction. The excitation winding is placed on the rotor, and stator teeth are set outside the stator with a gap in the middle of the stator teeth. Sinusoidal signal windings and cosine signal windings are set on the stator teeth, so that the air gap between the stator and rotor changes sinusoidally. This allows the signal windings to accurately sense sinusoidal signals for output, achieving high-precision angle measurement. In addition, the transformer can reduce the transformer size and realize a multi-pole structure design, solving the technical problem of large measurement errors in traditional wound rotary transformers.

[0029] like Figure 1 , Figure 2 As shown, rotor 1 is fitted outside stator 2, and equal air gaps 3 are provided between rotor 1 and stator 2.

[0030] The rotor 1 is made of magnetically conductive material and is located on the outside of the stator 2. The rotor 1 has a sinusoidal corrugated structure in the axial direction, such as... Figure 4 As shown.

[0031] Among them, the gap between rotor 1 and upper tooth 2-1 and lower tooth 2-3 is aligned, and the thickness of rotor 1 is equal to the axial length of upper tooth 2-1, with P pairs of peaks and valleys.

[0032] The excitation winding adopts an equal-turn winding method and is set on the rotor.

[0033] like Figure 5 , Figure 6 As shown, the rotor has multiple rotor slots evenly distributed along the rotor circumference. The excitation winding passes through each rotor slot, and the number of turns distributed in each slot is equal. Figure 2 , Figure 7 As shown, with rotor axis 9 (rotor axis 9 is taken as...) Using the rotor axis 10 as a reference, the 360° mechanical angle is divided into 2P parts in a counterclockwise direction, with each part having a mechanical angle of 180° / P. The excitation winding is wound in the forward direction within the first 180° / P mechanical angle, and wound in the reverse direction within the second 180° / P mechanical angle. The winding method for the other 2P-2 parts is similar.

[0034] The rotor slots are an even number not less than 4P, and the number of rotor slots is the same as the number of stator teeth. The positions of multiple rotor slots and multiple stator teeth correspond one-to-one. The stator 2 is made of stacked annular silicon steel sheets and is located inside the rotor 1. The outer surface of the stator 2 has 4NP identical tooth slots evenly distributed along its circumference. Stator teeth are positioned between adjacent slots, resulting in 4NP stator teeth on the outer surface of the stator. An annular stator through-slot 2-2 is formed along the circumference of the stator, dividing each stator tooth into an upper tooth 2-1 and a lower tooth 2-3. A set gap exists between the upper tooth 2-1 and the lower tooth 2-1, ultimately forming 4NP pairs of upper and lower teeth on the outer surface of the stator 2. The axial lengths of the upper teeth, lower teeth, and through-slot are equal. Here, N is a natural number, ranging from 2 to 15. P is the number of pole pairs.

[0035] The sine signal winding 5 and the cosine signal winding 6 are arranged in two layers on 4NP stator teeth, and the number of turns of the two signal windings varies according to a sine law, such as... Figure 3 , Figure 4 As shown. Specifically: Multiple stator teeth are evenly distributed along the circumference of stator 2.

[0036] Both the sine signal winding 5 and the cosine signal winding 6 are wound on the stator teeth in a sinusoidal winding manner, with a phase difference of 90° electrical angle. The number of turns of the sine signal winding 5 and the cosine signal winding 6 on each stator tooth is determined according to the amplitude of each signal and the number of stator teeth at the distance from the stator set axis.

[0037] For the sinusoidal signal winding 5, arbitrarily select a plane passing through the stator axis (stator axis 7 or stator axis 8) and not intersecting with the stator teeth, and divide the 4NP stator teeth into 4P groups in a clockwise direction. Starting from stator axis 7 or stator axis 8, the first group of adjacent N stator teeth is wound counterclockwise, the second group of adjacent N stator teeth is wound clockwise, and the remaining 4P-2 groups of stator teeth are wound in the same way as the first and second groups. The sinusoidal signal winding 5 and the cosine signal winding 6 have unique winding methods, and the winding methods of the sine and cosine signal windings are the same, with a phase difference of 90° electrical degrees.

[0038] The number of turns of the sine and cosine signal windings on each stator tooth is determined based on the amplitude of each signal and the number of stator teeth relative to the stator's set axis. Specifically: For a sinusoidal signal winding, the first i The number of turns on each stator tooth can be expressed as:

[0039] For the cosine signal winding, the first i The number of turns on each stator tooth can be expressed as:

[0040] In the formula, W 1i , W 2i For the first i The number of turns of the sinusoidal signal winding and the number of turns of the cosine signal winding on each stator tooth (W 1i , W 2i The value needs to be rounded down. W 1i , W 2i A negative value indicates reverse winding; Q 1. Q 2 represents the amplitude of the number of turns in the pre-fetched sine signal winding and the amplitude of the number of turns in the pre-fetched cosine signal winding, respectively; i The value range is 0~4NP, and the total number of stator teeth Z S =4NP.

[0041] The air gap magnetic permeability of each stator tooth It is a periodic function of the rotor's electrical angle. Expressed as a Fourier series:

[0042] In the formula, For mechanical rotation angle; Average permeability; for μ Second harmonic permeability amplitude; P This represents the number of rotor pole pairs; This refers to the number of stator teeth.

[0043] The excitation flux under each stator tooth is:

[0044] In the formula, It is a constant component of the magnetic flux; for μ Secondary harmonic flux amplitude.

[0045] Based on the connection method of the sine signal winding and the cosine signal winding, the flux linkage between the sine signal winding and the cosine signal winding can be expressed as:

[0046] Therefore, the output potential of the sinusoidal signal winding and the cosine signal winding can be expressed as:

[0047] In the formula, The amplitude of the induced electromotive force. W 1i , W 2i These are the number of turns of the sine signal winding and the cosine signal winding respectively on a single stator tooth.

[0048] As can be seen from the above formula, the rotor shape has sinusoidal properties, so that the amplitude of the induced electromotive force output by the sinusoidal winding and the cosine winding is a sine or cosine function of the rotor angle.

[0049] Therefore, the sinusoidal corrugated external rotor single-channel wound rotary transformer proposed in this embodiment of the invention can reduce the axial dimension of the rotary transformer through its unique stator and rotor structure, and solve the problem of large rotor magnetic circuit error, thereby improving the accuracy of angle measurement and enabling initial phase measurement for external rotor permanent magnet synchronous motors.

[0050] This invention also proposes a sinusoidal corrugated external rotor single-channel wound rotary transformer system, including a sinusoidal corrugated external rotor single-channel wound rotary transformer proposed in this invention.

[0051] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A sinusoidal corrugated external rotor single-channel wound rotary transformer, characterized in that, include: Stator, rotor, excitation winding, sine signal winding, and cosine signal winding; The rotor is fitted onto the outside of the stator; Multiple stator teeth are arranged on the outside of the stator along the circumferential direction. Each stator tooth includes an upper tooth and a lower tooth. The upper tooth and the lower tooth are arranged along the axial direction of the stator, and a gap is provided between the upper tooth and the lower tooth. Both the sine wave winding and the cosine wave winding are located on each stator tooth; The rotor has a sinusoidal corrugated structure in the axial direction, and the excitation winding is set on the rotor.

2. The sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Multiple stator teeth are evenly distributed along the circumference of the stator.

3. The sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The rotor thickness is equal to the axial length of the upper tooth.

4. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The axial lengths of the upper tooth, the lower tooth, and the gap between the upper and lower teeth are equal.

5. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The rotor is aligned with the gap between the upper and lower teeth.

6. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Both the sine signal winding and the cosine signal winding are wound on the stator teeth in a sinusoidal winding manner, with a phase difference of 90° electrical degrees.

7. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The number of turns of the sine signal winding and the cosine signal winding on each stator tooth is determined according to the amplitude of each signal and the number of stator teeth at the distance from the stator set axis.

8. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, An equal air gap is provided between the stator and the rotor.

9. A sinusoidal corrugated external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The excitation winding adopts an equal-turn winding method and is set on the rotor.

10. A sinusoidal corrugated external rotor single-channel wound rotary transformer system, characterized in that, Including the sinusoidal corrugated external rotor single-channel wound rotary transformer as described in any one of claims 1-9.

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