Annular outer rotor single-channel winding type rotary transformer and system
By adopting an annular outer rotor structure and a sinusoidal corrugated surface design in a wound rotary transformer, and combining the setting of sinusoidal signal windings and cosine signal windings, the problems of large integer turn error and large size of traditional wound rotary transformers are solved, and high-precision angle measurement and miniaturized design are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-13
AI Technical Summary
Traditional wound rotary transformers suffer from problems such as large integer turn errors, difficulty in achieving high-precision angle measurement, complex structure, and high cost.
It adopts an annular outer rotor structure, with a sinusoidal corrugated surface on the inner side of the rotor. A sinusoidal air gap is formed between the stator and the rotor. The sinusoidal signal winding and cosine signal winding are set on the stator, and the excitation winding is set on the rotor. The winding method of equal turns is adopted. The sinusoidal signal winding and cosine signal winding are 90° electrical angle apart on the stator teeth to reduce the error caused by integer turn distribution.
It achieves high-precision angle measurement, reduces transformer size, solves the problem of large measurement error in traditional wound rotary transformers, and is suitable for multi-pole structure design.
Smart Images
Figure CN121662579A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of transformer technology, and in particular to a toroidal 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 resolvers, used to control micromotors by providing analog signals, require a shaft-angle digital converter (SDC) to convert these analog signals into digital signals and provide angular position information. The accuracy of the resolver's angle measurement system is determined by both the resolver's own accuracy and the SDC's accuracy. Although wound-rotor resolvers are more complex in structure than reluctance resolvers, their accuracy is unmatched, and their production cost is also much lower. Therefore, brushless wound-rotor resolvers hold an irreplaceable position as an angle measuring element. They offer advantages such as reliable structure, long lifespan, and strong anti-interference capabilities. They are also easy to install, provide rotor position angles even when the motor is stationary, and can operate in various harsh environments, including humid, high-temperature, and extremely cold conditions.
[0004] Traditional wound-rotor rotary transformers have one set of primary windings in the rotor and two sets of secondary windings in the stator, which is not conducive to the use of a dual-channel structure. Even a single-channel structure is limited by integer turn errors. This type of rotary transformer requires the sinusoidal distribution of the number of turns in the rotor windings to achieve a sinusoidal change in the air gap magnetic flux between the stator and rotor. It is difficult to achieve a dual-channel magnetic circuit structure. The difficulty lies in the fact that the dual-channel magnetic circuit requires the synthesis of sinusoidal functions of different frequencies. The windings exhibit an asymmetrical distribution pattern over the entire circumference, making the winding process very cumbersome. Furthermore, when using the traditional sinusoidal winding method, the number of turns in each slot of the rotor is an integer number of turns. Even if the winding is achieved through a cumbersome process, the integer turn distribution will still lead to large signal output errors. Summary of the Invention
[0005] To address the aforementioned problems, this invention proposes a toroidal external rotor single-channel wound rotary transformer and system. The transformer has a sinusoidally varying air gap between its stator and rotor, enabling high-precision angle measurement, and the transformer is also relatively small in size.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: In the first aspect, a toroidal external rotor single-channel wound rotary transformer is proposed, comprising: a stator, a rotor, an excitation winding, a sine signal winding, and a cosine signal winding; The rotor is fitted onto the outside of the stator; The inner side of the rotor is a sinusoidal corrugated surface, and an air gap with the stator is formed with a sinusoidal variation between the sinusoidal corrugated surface and the stator; Both the sine signal winding and the cosine signal winding are located on the stator, while the excitation winding is located on the rotor.
[0007] Furthermore, multiple radial salient pole structures are provided on the inner side of the rotor. The radial salient pole structures are sinusoidal structures, which makes the inner side of the rotor form a sinusoidal corrugated surface.
[0008] Furthermore, the excitation winding is arranged on the rotor using an equal-turn winding method.
[0009] Furthermore, the rotor is provided with multiple rotor slots, and the excitation windings are distributed in each rotor slot.
[0010] Furthermore, the winding directions of the excitation windings in adjacent rotor slots are opposite.
[0011] Furthermore, multiple stator teeth are arranged on the outside of the stator along the circumferential direction, and both the sine signal winding and the cosine signal winding are arranged on each stator tooth.
[0012] 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.
[0013] Furthermore, the number of turns of the sine signal winding and the cosine signal winding on each stator tooth is determined according to the number of stator teeth on the stator axis based on the amplitude and distance of each signal.
[0014] Furthermore, the stator is made of stacked annular silicon steel sheets.
[0015] Secondly, a toroidal external rotor single-channel wound rotary transformer system is proposed, including the toroidal 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 toroidal external rotor single-channel wound rotary transformer and system. The transformer features a rotor positioned outside the stator, with the inner side of the rotor configured as a sinusoidal corrugated surface. An air gap with a sinusoidal variation is formed between the sinusoidal corrugated surface and the stator. Sinusoidal and cosine signal windings are located on the stator, while the excitation winding is located on the rotor. This allows the signal windings to accurately sense and output sinusoidal signals, achieving high-precision angle measurement. This invention presents a novel transformer structure that, while achieving high-precision angle measurement, also boasts 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 the structure of a single-channel wound rotary transformer with an annular external rotor according to an embodiment of the present invention; Figure 2 This is a diagram showing the turn distribution of the sine and cosine signal windings of a toroidal external rotor single-channel wound rotary transformer according to an embodiment of the present invention. Figure 3 This is a diagram showing the number of turns in the excitation winding.
[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. 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 have one set of primary windings in the rotor and two sets of secondary windings in the stator, which is not conducive to the use of a dual-channel structure. Even a single-channel structure is limited by integer turn errors. This type of rotary transformer requires the sinusoidal distribution of the number of turns in the rotor windings to achieve a sinusoidal change in the air gap magnetic flux between the stator and rotor. It is difficult to achieve a dual-channel magnetic circuit structure. The difficulty lies in the fact that the dual-channel magnetic circuit requires the synthesis of sinusoidal functions of different frequencies. The windings exhibit an asymmetrical distribution pattern over the entire circumference, making the winding process very cumbersome. Furthermore, when using the traditional sinusoidal winding method, the number of turns in each slot of the rotor is an integer number of turns. Even if the winding is achieved through a cumbersome process, the integer turn distribution will still 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 single-channel wound rotary transformer with an annular external rotor, such as... Figures 1-3 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; The inner side of rotor 1 is a sinusoidal corrugated surface, and an air gap with sinusoidal variation is formed between the sinusoidal corrugated surface and stator 2. The sine signal winding 5 and the cosine signal winding 6 are both placed on the stator 2, and the excitation winding 4 is placed on the rotor 1.
[0028] This invention proposes a toroidal external rotor single-channel wound rotary transformer. By placing the rotor outside the stator and setting the inner side of the rotor as a sinusoidal corrugated surface, a sinusoidally varying air gap is formed between the sinusoidal corrugated surface and the stator. Sinusoidal signal windings and cosine signal windings are set on the stator, and the excitation winding is set on the rotor. This allows the signal windings to accurately sense sinusoidal signals for output, achieving high-precision angle measurement. In addition, the transformer can reduce its 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 As shown, rotor 1 is fitted outside stator 2, and an air gap 3 with a sinusoidal variation is provided between rotor 1 and stator 2.
[0030] Multiple stator teeth are arranged circumferentially on the outside of stator 2. The sine signal winding 5 and the cosine signal winding 6 are both located on each stator tooth. Specifically: The stator 2 is made of stacked annular silicon steel sheets and is located inside the rotor 1. The outer surface of the stator has 4NP slots along the axial direction. The value of N ranges from 2 to 15. Stator teeth are arranged between adjacent slots, so the stator also has 4NP teeth. The sine signal winding 5 and the cosine signal winding 6 are arranged in two layers on the 4NP stator teeth, and the number of turns of the two signal windings varies according to a sine law, such as... Figure 2 As shown.
[0031] Multiple stator teeth are evenly distributed along the circumference of stator 2.
[0032] 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 number of stator teeth on the stator axis based on the amplitude and distance of each signal.
[0033] 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 winding method of the other 4P-2 groups of stator teeth is the same as that of the first and second groups of stator teeth.
[0034] The number of turns of the sine and cosine signal windings on each stator tooth is determined by the number of stator teeth along the stator axis based on the amplitude and distance of each signal. Specifically: For a sinusoidal signal winding, the first i The number of turns on each stator tooth can be expressed as:
[0035] For the cosine signal winding, the first i The number of turns on each stator tooth can be expressed as:
[0036] 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.
[0037] Rotor 1 is made of magnetically conductive material and is located on the outside of stator 2, such as Figure 1 As shown, multiple radial salient pole structures are provided on the inner side of rotor 1. The radial salient pole structures are sinusoidal structures, which makes the inner side of rotor 1 form a sinusoidal corrugated surface.
[0038] In this embodiment of the invention, the radial salient pole structure arranged inside the rotor 1 is a multi-pole sinusoidal structure designed using a magnetic field optimization function. P is the number of pole pairs of the rotor, and the excitation winding 4 is arranged on the rotor using an equal-turn winding method. Specifically, the rotor is provided with multiple rotor slots, and the excitation windings are distributed in each rotor slot; and the winding directions of the excitation windings 4 in adjacent rotor slots are opposite.
[0039] like Figure 1 As shown, with rotor axis 9 or rotor axis 10 (rotor axis is taken as...) Using the position 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 in the reverse direction within the second 180° / P mechanical angle. The winding method for the remaining 2P-2 parts follows the same pattern. The rotor has an even number of slots, not less than 4P.
[0040] 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:
[0041] In the formula For mechanical rotation angle; Average permeability; The amplitude of the μ-th harmonic permeability; P is the number of rotor pole pairs; This refers to the number of stator teeth.
[0042] The excitation flux under each stator tooth is:
[0043] In the formula, It is a constant component of the magnetic flux; It represents the amplitude of the μth harmonic magnetic flux.
[0044] Depending on the connection method between the sine and cosine windings, the magnetic flux linkage between the sine and cosine windings... and It can be represented as:
[0045] Therefore, the output potential of the sine winding and the cosine winding e s and e c It can be represented as:
[0046] In the formula, The amplitude of the induced electromotive force. and These are the number of turns of the sine signal winding and the cosine signal winding respectively on a single stator tooth.
[0047] As can be seen from the above formula, the rotor shape has a sinusoidal property, 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.
[0048] Therefore, the annular 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 rotor structure, and solve the problem of large rotor magnetic circuit error, thereby improving the accuracy of angle measurement. It can be used for initial phase measurement of external rotor permanent magnet synchronous motors.
[0049] This invention also proposes a toroidal external rotor single-channel wound rotary transformer system, including a toroidal external rotor single-channel wound rotary transformer proposed in this invention.
[0050] 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 toroidal 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; The inner side of the rotor is a sinusoidal corrugated surface, and an air gap with the stator is formed with a sinusoidal variation between the sinusoidal corrugated surface and the stator; Both the sine signal winding and the cosine signal winding are located on the stator, while the excitation winding is located on the rotor.
2. The toroidal external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Multiple radial salient pole structures are arranged on the inner side of the rotor. The radial salient pole structures are sinusoidal structures, which makes the inner side of the rotor form a sinusoidal corrugated surface.
3. The toroidal external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The excitation winding is installed on the rotor using an equal-turn winding method.
4. A toroidal external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The rotor has multiple rotor slots, and the excitation windings are distributed in each rotor slot.
5. A single-channel wound rotary transformer with an annular external rotor as described in claim 4, characterized in that, The winding directions of the excitation windings in adjacent rotor slots are opposite.
6. A toroidal external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Multiple stator teeth are arranged on the outside of the stator along the circumferential direction, and both the sine signal winding and the cosine signal winding are arranged on each stator tooth.
7. A toroidal 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.
8. A toroidal 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 number of stator teeth on the stator axis based on the amplitude and distance of each signal.
9. A toroidal external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The stator is made of stacked annular silicon steel sheets.
10. A single-channel wound-rotor rotary transformer system with an annular external rotor, characterized in that, Including the toroidal external rotor single-channel wound rotary transformer as described in any one of claims 1-9.