A method for analyzing the amplitude of output voltage signal of rotary transformer

Abstract

The present invention discloses a method for analyzing the amplitude of a rotary transformer. This method determines whether the rotary transformer is in an unstable or stable state by taking the average voltage value of the rotary transformer's output voltage signal. The method then obtains a standard output voltage signal corresponding to the state, accurately extracting the amplitude of the rotary transformer's output voltage signal for subsequent amplitude error analysis. This method can avoid amplitude error analysis errors caused by signal interference and distortion when the rotary transformer is in an unstable state.

Description

Technical Field

[0001] The present invention relates to the field of rotary transformers, and in particular to an output voltage signal analysis method for rotary transformers. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) are increasingly used in a variety of modern high-performance applications due to their simple and reliable structure, maintenance-free operation, high efficiency, and excellent control performance. In most applications, PMSMs employ a rotor field-oriented vector control strategy, often requiring a resolver to provide absolute rotor position. A resolver is an electromagnetic sensor consisting of a stator winding and a rotor winding. The stator winding serves as the resolver's primary, while the rotor winding serves as the resolver's secondary. The induced voltage is generated through electromagnetic coupling.

[0003] During operation, the resolver outputs a weak analog signal. However, when a permanent magnet synchronous motor starts, stops, or experiences sudden load changes, it generates large current surges and strong magnetic fields. This puts the resolver in an unstable state, and the output signals of its sine and cosine windings are easily interfered with by the surrounding magnetic field, causing severe distortion and distortion of the output voltage signal. This can lead to various errors in subsequent resolver analysis, particularly serious errors in amplitude error analysis. Therefore, it is necessary to find a method for analyzing the amplitude of the resolver's output voltage signal to accurately determine the resolver's output voltage signal and avoid amplitude error analysis errors caused by signal interference and distortion when the resolver is unstable. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide an amplitude analysis method for a rotary transformer, which can accurately obtain the output voltage signal amplitude of the rotary transformer and avoid amplitude error analysis errors caused by signal interference and distortion when the rotary transformer is in an unstable state.

[0005] The present invention provides a method for analyzing the amplitude of a rotary transformer, comprising:

[0006] Step S1: At the preset time T s Within the preset time T, the voltage average value of the output voltage signal of the rotary transformer is obtained to determine whether the rotary transformer is in an unstable state; wherein the preset time T s Set to a half voltage period of the output voltage signal of the rotary transformer;

[0007] Step S2, when it is determined that the rotary transformer is in a stable state, obtaining the output voltage standard signal of the rotary transformer, and proceeding to step S4; when it is determined that the rotary transformer is in an unstable state, proceeding to step S3;

[0008] Step S3, when it is determined that the rotary transformer is in an unstable state, remove harmonic interference, obtain the output voltage standard signal of the rotary transformer, and proceed to step S4;

[0009] Step S4: extracting the amplitude of the output voltage standard signal of the rotary transformer.

[0010] Furthermore, the step S1 includes:

[0011] Step S11: at the preset time T s sampling the output voltage signal of the rotary transformer to obtain an output voltage sampling signal, and acquiring the voltage average value of the output voltage signal of the rotary transformer;

[0012] Step S12, judging whether the resolver is in an unstable state according to the voltage average value of the output voltage signal of the resolver;

[0013] Step S13: When it is determined that the resolver is in an unstable state for N consecutive times, it is finally determined that the resolver is in an unstable state at this time; otherwise, it is determined that the resolver is in a stable state at this time.

[0014] Furthermore, the step S11 includes: calculating a voltage average value of the output voltage signal of the resolver between two zero-crossing points of the output voltage sampling signal.

[0015] Furthermore, the judgment basis of step S12 is:

[0016]

[0017] Among them, U avg (k) represents the average voltage of the kth half voltage cycle of the output voltage sampling signal, U avg (k-1) represents the average voltage of the k-1th half voltage cycle of the output voltage sampling signal, U th Indicates the allowable voltage unbalance value.

[0018] Furthermore, N≥3.

[0019] Furthermore, the step of obtaining the output voltage standard signal of the rotary transformer in step S2 specifically includes: directly using the output voltage sampling signal as the output voltage standard signal of the rotary transformer.

[0020] Furthermore, the step S3 of obtaining the output voltage standard signal of the rotary transformer specifically includes: performing fast Fourier decomposition on the output voltage sampling signal to obtain the fundamental component of the output voltage sampling signal as the output voltage standard signal of the rotary transformer.

[0021] Furthermore, the amplitude analysis method further includes:

[0022] Step S5: performing amplitude error analysis based on the extracted amplitude of the output voltage standard signal.

[0023] Furthermore, the rotary transformer is a sine-cosine rotary transformer.

[0024] The beneficial technical effects of the present invention are:

[0025] The present invention discloses a method for analyzing the amplitude of a rotary transformer. The method determines whether the rotary transformer is in an unstable state or a stable state by taking the voltage average value of the output voltage signal of the rotary transformer, obtains the output voltage standard signal in the corresponding state, accurately extracts the output voltage signal amplitude of the rotary transformer, and avoids amplitude error analysis errors caused by signal interference and distortion when the rotary transformer is in an unstable state. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, 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 any creative work.

[0027] Figure 1 A flowchart of a method for analyzing the amplitude of a rotary transformer provided by the present invention;

[0028] Figure 2 This is a flow chart for determining the unstable state of the rotary transformer provided by the present invention. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] The present invention provides an amplitude analysis method for a rotary transformer, which can accurately obtain the output voltage signal amplitude of the rotary transformer and avoid amplitude error analysis errors caused by signal interference and distortion when the rotary transformer is in an unstable state.

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 The following is a flow chart of a method for analyzing the amplitude of a rotary transformer provided by the present invention. The present invention is applicable to any type of rotary transformer, particularly a sine-cosine rotary transformer. The method can be performed by an amplitude analysis device for a rotary transformer, which can be implemented in software and / or hardware. The amplitude analysis method specifically includes the following steps:

[0033] Step S1: At the preset time T s The average voltage of the output voltage signal of the rotary transformer is obtained to determine whether the rotary transformer is in an unstable state, wherein the preset time T s Set to half the voltage period of the resolver's output voltage signal.

[0034] When a permanent magnet synchronous motor starts, stops, or experiences sudden load changes, it generates large current surges and strong magnetic fields, putting the resolver in an unstable state. The output voltage signals of its sine and cosine windings are easily disturbed by the surrounding magnetic field, causing severe distortion and distortion of the sine and cosine output voltage signals. This, in turn, can cause a significant imbalance in the average values ​​of the sine and cosine output voltage signals within a half-voltage cycle. Therefore, in this application, the average value of the output voltage signal within a half-voltage cycle is used to determine whether the resolver is in an unstable state.

[0035] Specifically, when the resolver begins operation, its sine winding and cosine winding generate a sine output voltage signal and a cosine output voltage signal. A voltage sampling device samples the sine output voltage signal and the cosine output voltage signal to obtain corresponding output voltage sampling signals. Between two zero-crossing points of the output voltage sampling signals, an average voltage of the resolver's output voltage signal is calculated.

[0036] Whether the rotary transformer is in an unstable state is determined based on the following:

[0037]

[0038] Among them, U avg (k) represents the average voltage of the kth half voltage cycle of the output voltage sampling signal, U avg (k-1) represents the average voltage of the k-1th half voltage cycle of the output voltage sampling signal, U th Indicates the allowable voltage unbalance value.

[0039] Furthermore, the present invention finally determines that the rotary transformer is in an unstable state only after it is determined N times in a row that the rotary transformer is in an unstable state, thereby improving the reliability of determining whether the rotary transformer is in an unstable state, wherein N≥3.

[0040] In one embodiment of the present application, Figure 2 As shown, at the preset time T s The voltage average value of the output voltage signal of the resolver is obtained to determine whether the resolver is in an unstable state, which specifically includes the following steps:

[0041] Step S11: At the preset time T s The output voltage signal of the rotary transformer is sampled to obtain an output voltage sampling signal, and the voltage average value of the output voltage signal of the rotary transformer is obtained, wherein the preset time T s Set to half the voltage period of the resolver's output voltage signal.

[0042] Step S12: judging whether the resolver is in an unstable state according to the voltage average value of the output voltage signal of the resolver.

[0043] Step S13: When the resolver is determined to be in an unstable state for N consecutive times, it is finally determined that the resolver is in an unstable state at this time, where N≥3; otherwise, it is determined that the resolver is in a stable state at this time.

[0044] Step S2: When it is determined that the rotary transformer is in a stable state, the output voltage standard signal of the rotary transformer is obtained; when it is determined that the rotary transformer is in an unstable state, the process proceeds to step S3.

[0045] Acquiring the output voltage standard signal of the resolver specifically includes: directly using the output voltage sampling signal as the output voltage standard signal of the resolver.

[0046] When the resolver is in a stable state, the output voltage signal of the resolver is not interfered with or distorted, so the amplitude of the output voltage sampling signal can be directly extracted at this time.

[0047] Step S3: When it is determined that the rotary transformer is in an unstable state, harmonic interference is removed and a standard output voltage signal of the rotary transformer is obtained.

[0048] Acquiring the output voltage standard signal of the rotary transformer specifically includes: performing fast Fourier decomposition on the output voltage sampling signal to obtain the fundamental component of the output voltage sampling signal as the output voltage standard signal of the rotary transformer.

[0049] When the resolver is in an unstable state, the sine output voltage signal and cosine output voltage signal of the resolver will be interfered with and distorted. Therefore, it is necessary to perform fast Fourier decomposition on the sine output voltage sampling signal or the cosine output voltage sampling signal to remove the harmonic influence and retain only the fundamental signal for amplitude extraction.

[0050] Step S4: extracting the amplitude of the output voltage standard signal of the rotary transformer.

[0051] Furthermore, this application also includes:

[0052] Step S5: performing amplitude error analysis based on the extracted output voltage standard signal amplitude.

[0053] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0054] The foregoing description shows and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the inventive concept described herein by the teachings above or by techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be within the scope of the appended claims.

Claims

1. A method for analyzing the amplitude of a rotary transformer, characterized in that: include: Step S1: At a preset time T s Within the preset time T, the voltage average value of the output voltage signal of the rotary transformer is obtained to determine whether the rotary transformer is in an unstable state; wherein the preset time T s Set to a half voltage period of the output voltage signal of the rotary transformer; Step S2, when it is determined that the rotary transformer is in a stable state, obtaining the output voltage standard signal of the rotary transformer, and proceeding to step S4; when it is determined that the rotary transformer is in an unstable state, proceeding to step S3; Step S3, when it is determined that the rotary transformer is in an unstable state, remove harmonic interference, obtain the output voltage standard signal of the rotary transformer, and proceed to step S4; Step S4, extracting the amplitude of the output voltage standard signal of the rotary transformer; The step S1 comprises: Step S11: at the preset time T s sampling the output voltage signal of the rotary transformer to obtain an output voltage sampling signal, and acquiring the voltage average value of the output voltage signal of the rotary transformer; Step S12, judging whether the resolver is in an unstable state according to the voltage average value of the output voltage signal of the resolver; Step S13: When it is determined that the resolver is in an unstable state for N consecutive times, it is finally determined that the resolver is in an unstable state at this time; otherwise, it is determined that the resolver is in a stable state at this time.

2. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: The step S11 includes: calculating the voltage average value of the output voltage signal of the rotary transformer between two zero-crossing points of the output voltage sampling signal.

3. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: The judgment basis of step S12 is: ； Among them, U avg (k) represents the average voltage of the kth half voltage cycle of the output voltage sampling signal, U avg (k-1) represents the average voltage of the k-1th half voltage cycle of the output voltage sampling signal, U th Indicates the allowable voltage unbalance value.

4. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: N≥3。 5. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: The step S2 of obtaining the output voltage standard signal of the rotary transformer specifically includes: directly using the output voltage sampling signal as the output voltage standard signal of the rotary transformer.

6. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: Acquiring the output voltage standard signal of the rotary transformer in step S3 specifically includes: performing fast Fourier decomposition on the output voltage sampling signal to obtain the fundamental component of the output voltage sampling signal as the output voltage standard signal of the rotary transformer.

7. The method for analyzing the amplitude of a rotary transformer according to claim 1, wherein: The amplitude analysis method further includes: Step S5: performing amplitude error analysis based on the extracted amplitude of the output voltage standard signal.

8. The amplitude analysis method of a rotary transformer according to claim 1, characterized in that: The rotary transformer is a sine-cosine rotary transformer.

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