CN114705913B - Harmonic analysis method of rotary transformer - Google Patents
Harmonic analysis method of rotary transformer Download PDFInfo
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- CN114705913B CN114705913B CN202210380528.0A CN202210380528A CN114705913B CN 114705913 B CN114705913 B CN 114705913B CN 202210380528 A CN202210380528 A CN 202210380528A CN 114705913 B CN114705913 B CN 114705913B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/16—Spectrum analysis; Fourier analysis
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The invention discloses a harmonic analysis method of a rotary transformer, which is characterized in that sampling is carried out between continuous even number rising edges or continuous even number falling edges of zero crossing indication signals, sampling signals are obtained through curve fitting, fundamental wave signal components are subtracted, new total harmonic signals are obtained, and finally Fourier FFT transformation is carried out, so that all harmonic signal components in a frequency domain are obtained. The method can avoid the problems of spectrum aliasing, leakage and the like in the harmonic analysis process, so that the higher harmonic signal component is decomposed more thoroughly and accurately, and the accuracy of harmonic analysis is improved.
Description
Technical Field
The invention relates to the field of rotary transformers, in particular to a harmonic analysis method of a rotary transformer.
Background
The sine-cosine resolver is used as a high-precision angle sensor, and outputs a voltage signal in a sine-cosine relation with the rotor angle, and is often used as a motor angle resolving element or a position sensor. Because the working rotation speed of the motor is high, the corresponding armature winding inductance is lower and the electric frequency is higher. In order to control a low inductance, high electrical frequency motor, the power tubes in the motor controller need to operate at a higher switching frequency. The increase of the switching frequency and the increase of the switching speed of the power tube can cause the increase of electromagnetic interference of the outward radiation of the armature winding of the motor, and a large amount of higher harmonics are generated in the output signal of the rotary transformer, so that the output signal generates a certain degree of waveform distortion.
The existing harmonic analysis means mainly comprise a Fourier FFT method, a wavelet analysis method, an empirical mode decomposition method and the like. First, it is known from the nyquist theorem that ideal integer periodic frequency sampling is often used in extracting harmonic components. However, it is difficult to achieve integer period sampling of the signal during actual signal acquisition. Sampling of non-integer periods may lead to problems of aliasing, leakage, etc. of the spectrum during harmonic analysis, resulting in inaccuracy of subsequent harmonic analysis. Secondly, because the higher harmonic component is far smaller than the fundamental component of the rotary transformer, the higher harmonic component is submerged in the fundamental component, so that the higher harmonic component is not thoroughly and accurately decomposed, and the follow-up harmonic analysis is inaccurate.
Disclosure of Invention
In view of the above problems, the present invention has been made to provide a harmonic analysis method for a resolver, which samples the resolver for an integer period to obtain a sampled signal of the resolver, subtracts a fundamental component, and then decomposes a higher harmonic component, thereby improving the accuracy of harmonic analysis.
The invention provides a harmonic analysis method of a rotary transformer, which comprises the following steps:
step S1, a zero-crossing comparison module is constructed, and an output signal of a rotary transformer is compared with a reference zero value to generate a zero-crossing indication signal;
step S2, triggering an ADC conversion module to sample an output signal of the rotary transformer between continuous even number of rising edges or continuous even number of falling edges of the zero-crossing indication signal, and obtaining a sampling signal X (t) through curve fitting;
s3, carrying out Fourier FFT (fast Fourier transform) on the sampling signal X (t) to obtain N signal components corresponding to N frequencies in a frequency domain, wherein N is more than or equal to 2;
step S4, obtaining the signal component with the largest amplitude in the N signal components as a fundamental wave signal component X of the output signal of the rotary transformer fun (t)；
Step S5, subtracting the fundamental wave signal component from the sampling signal X (t) to obtain a new total harmonic signal X har (t)；
Step S6, for the new total harmonic signal X har (t) re-performing a fourier FFT transformation to obtain individual harmonic signal components in the frequency domain.
Further, the harmonic analysis method further includes:
step S7, according to the fundamental wave signal component X fun (t) and the respective harmonic signal components to obtain a harmonic total distortion rate THD.
Further, the harmonic total distortion ratio THD is:
wherein k is harmonic order, X eff1 X is the effective value of the fundamental wave signal component effk Is the k-th harmonic signal component effective value.
Further, the output signal of the rotary transformer is a sine signal or a cosine signal.
Further, the step S2 further includes:
and triggering the ADC conversion module to sample the output signal of the rotary transformer between two continuous rising edges or two continuous falling edges of the zero crossing indication signal.
Further, the curve fitting adopts a least square method or a cubic spline interpolation method.
Further, X har (t)＝X(t)-X fun (t)。
Further, the rotary transformer is a sine-cosine rotary transformer.
The beneficial technical effects of the invention are as follows:
(1) According to the harmonic analysis method of the rotary transformer, provided by the invention, the continuous even number of rising edges or the continuous even number of falling edges of the zero-crossing indication signal are utilized to sample the rotary transformer in an integer period to obtain the sampling signal of the rotary transformer, so that the problems of spectrum aliasing, leakage and the like in the harmonic analysis process can be avoided, and the accuracy of subsequent harmonic analysis is improved.
(2) According to the harmonic analysis method of the rotary transformer, provided by the invention, the harmonic component is decomposed after the fundamental component is subtracted by the sampling signal, so that the influence of the fundamental component is avoided, the subsequent harmonic component is decomposed more thoroughly and accurately, and the accuracy of harmonic analysis is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for harmonic analysis of a resolver according to the present invention;
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
The invention provides a harmonic analysis method of a rotary transformer, which is used for sampling the rotary transformer in integer period to obtain a sampling signal of the rotary transformer, subtracting a fundamental component and then decomposing a higher harmonic component, thereby improving the accuracy of harmonic analysis.
The invention will be described in further detail with reference to the accompanying drawings and specific examples.
Fig. 1 is a flowchart of a harmonic analysis method of a resolver according to the present invention. The invention is applicable to any type of resolver, in particular a sine-cosine resolver. The method can be performed by a harmonic analysis device of a rotary transformer, which can be implemented in software and/or hardware, and comprises the following steps:
step S1, a zero-crossing comparison module is constructed, and an output signal of the rotary transformer is compared with a reference zero value to generate a zero-crossing indication signal.
In this embodiment of the present application, the output signal of the resolver is a sine signal or a cosine signal, and the zero-crossing comparison module is used to compare the sine signal or the cosine signal with a reference zero value, so as to generate a zero-crossing indication signal with a high-low level change.
And S2, triggering an ADC conversion module to sample the output signal of the rotary transformer between the continuous even number of rising edges or the continuous even number of falling edges of the zero-crossing indication signal, and obtaining a sampling signal X (t) through curve fitting.
Specifically, in this embodiment of the present application, the ADC conversion module may be triggered to sample the output signal of the resolver between two consecutive rising edges or two consecutive falling edges of the zero-crossing indication signal.
Because the zero-crossing indication signal is a rectangular wave with high and low level change, the time between two continuous rising edges or two continuous falling edges of the zero-crossing indication signal is the period of the output signal of the rotary transformer. Therefore, the period of the sampling signal strictly corresponds to the integer multiple period of the output signal of the rotary transformer, the problems of spectrum aliasing, leakage and the like in the harmonic analysis process can be avoided, and the accuracy of the subsequent harmonic analysis is improved.
Further, in order to improve accuracy of harmonic analysis, the present application may further trigger the ADC conversion module to sample the output signal of the resolver between consecutive even rising edges or consecutive even falling edges of the zero-crossing indication signal, where even rising edges or even falling edges refer to rising edges or falling edges greater than two.
In this embodiment of the present application, the curve fitting may employ least squares or cubic spline interpolation.
And S3, carrying out Fourier FFT (fast Fourier transform) on the sampling signal X (t) to obtain N signal components corresponding to N frequencies in a frequency domain, wherein N is more than or equal to 2.
Step S4, obtaining the signal component with the largest amplitude in the N signal components as a fundamental wave signal component X of the output signal of the rotary transformer fun (t)。
Step S5, subtracting from the sampling signal X (t)Fundamental wave signal component, obtain new total harmonic signal X har (t)。
Wherein X is har (t)＝X(t)-X fun (t)。
In the method, the harmonic component is far smaller than the fundamental component of the rotary transformer, and the harmonic component is not thoroughly and accurately decomposed, so that the fundamental signal component is subtracted by using the sampling signal X (t), the influence of the fundamental signal component is avoided, and the subsequent harmonic signal component is thoroughly and accurately decomposed.
Step S6, for the new total harmonic signal X har (t) re-performing a fourier FFT transformation to obtain individual harmonic signal components in the frequency domain.
Step S7, according to the fundamental wave signal component X fun (t) and the respective harmonic signal components to obtain a harmonic total distortion rate THD.
In this application, the definition of the harmonic total distortion rate THD is the total harmonic content of the signal expressed as a percentage of the fundamental signal. The total harmonic content of the signal reflects the distortion characteristics of the waveform, and the formula is defined as follows:
wherein k is harmonic order, X eff1 X is the effective value of the fundamental wave signal component effk Is the k-th harmonic signal component effective value.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a product or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such product or system. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a commodity or system comprising such elements.
While the foregoing description illustrates and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as limited to other embodiments, and is capable of numerous other combinations, modifications and environments and is capable of changes or modifications within the scope of the inventive concept as described herein, either as a result of the foregoing teachings or as a result of the knowledge or technology in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the invention are intended to be within the scope of the appended claims.
Claims (1)
1. A method of harmonic analysis of a resolver, comprising:
step S1, a zero-crossing comparison module is constructed, and an output signal of a rotary transformer is compared with a reference zero value to generate a zero-crossing indication signal;
step S2, triggering an ADC conversion module to sample an output signal of the rotary transformer between continuous even number of rising edges or continuous even number of falling edges of the zero-crossing indication signal, avoiding spectrum aliasing and leakage in the harmonic analysis process, and obtaining a sampling signal X (t) through curve fitting; the curve fitting adopts a least square method or a cubic spline interpolation method;
s3, carrying out Fourier FFT (fast Fourier transform) on the sampling signal X (t) to obtain N signal components corresponding to N frequencies in a frequency domain, wherein N is more than or equal to 2;
step S4, obtaining the signal component with the largest amplitude in the N signal components as a fundamental wave signal component X of the output signal of the rotary transformer fun (t)；
Step S5, subtracting the fundamental wave signal component from the sampling signal X (t) to obtain a new total harmonic signal X har (t), i.e. X har (t)＝X(t)-X fun (t)；
Step S6, for the new total harmonic signal X har (t) re-performing a fourier FFT to obtain each harmonic signal component in the frequency domain;
step S7, according to the fundamental wave signal component X fun (t) obtaining a harmonic total distortion rate THD with each harmonic signal component;
the harmonic total distortion rate THD is as follows:
wherein k is harmonic order, X eff1 X is the effective value of the fundamental wave signal component effk Is the effective value of k harmonic signal components;
according to the harmonic analysis method, the fundamental wave signal component is subtracted from the sampling signal to decompose the harmonic signal component, so that the harmonic signal component is prevented from being submerged in the fundamental wave signal component, the harmonic signal component is decomposed more thoroughly and accurately, and the accuracy of harmonic analysis is improved;
the step S2 further includes: triggering an ADC conversion module to sample an output signal of the rotary transformer between two continuous rising edges or two continuous falling edges of the zero-crossing indication signal;
the output signal of the rotary transformer is a sine signal or a cosine signal, and the rotary transformer is a sine-cosine rotary transformer.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5487016A (en) * | 1994-11-04 | 1996-01-23 | Eaton Corporation | Apparatus for generating a signal representative of total harmonic distortion in waveforms of an A/C electrical system |
| CN101447672A (en) * | 2008-09-22 | 2009-06-03 | 陈甲标 | Novel full frequency spectrum electrical active filter |
| CN102253282A (en) * | 2011-06-10 | 2011-11-23 | 中国矿业大学 | Method for obtaining continuous frequency spectrum interpolation power harmonic parameter of Nuttall window function |
| CN102565523A (en) * | 2012-01-12 | 2012-07-11 | 上海理工大学 | Current harmonic detection system and working method |
| CN103592513A (en) * | 2013-11-20 | 2014-02-19 | 北京富根智能电表有限公司 | Power signal harmonic analysis method and device |
| CN105445546A (en) * | 2015-12-31 | 2016-03-30 | 杭州海兴电力科技股份有限公司 | Fiber access type electric energy meter with function of harmonic detection |
| CN109061302A (en) * | 2018-08-30 | 2018-12-21 | 内蒙古工业大学 | A kind of wind power generator incorporated in power network group harmonic measure system converted based on EEMD and Hilbert |
| CN109725200A (en) * | 2019-01-25 | 2019-05-07 | 江苏大学 | A kind of adaptive frequency analysis system and its analysis method |
| CN110719043A (en) * | 2019-11-21 | 2020-01-21 | 深圳国能电气有限公司 | Inverter harmonic compensation method and control device thereof |
| CN113030570A (en) * | 2021-03-22 | 2021-06-25 | 宁夏隆基宁光仪表股份有限公司 | Harmonic electric energy detection method and adaptive filter |
-
2022
- 2022-04-12 CN CN202210380528.0A patent/CN114705913B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5487016A (en) * | 1994-11-04 | 1996-01-23 | Eaton Corporation | Apparatus for generating a signal representative of total harmonic distortion in waveforms of an A/C electrical system |
| CN101447672A (en) * | 2008-09-22 | 2009-06-03 | 陈甲标 | Novel full frequency spectrum electrical active filter |
| CN102253282A (en) * | 2011-06-10 | 2011-11-23 | 中国矿业大学 | Method for obtaining continuous frequency spectrum interpolation power harmonic parameter of Nuttall window function |
| CN102565523A (en) * | 2012-01-12 | 2012-07-11 | 上海理工大学 | Current harmonic detection system and working method |
| CN103592513A (en) * | 2013-11-20 | 2014-02-19 | 北京富根智能电表有限公司 | Power signal harmonic analysis method and device |
| CN105445546A (en) * | 2015-12-31 | 2016-03-30 | 杭州海兴电力科技股份有限公司 | Fiber access type electric energy meter with function of harmonic detection |
| CN109061302A (en) * | 2018-08-30 | 2018-12-21 | 内蒙古工业大学 | A kind of wind power generator incorporated in power network group harmonic measure system converted based on EEMD and Hilbert |
| CN109725200A (en) * | 2019-01-25 | 2019-05-07 | 江苏大学 | A kind of adaptive frequency analysis system and its analysis method |
| CN110719043A (en) * | 2019-11-21 | 2020-01-21 | 深圳国能电气有限公司 | Inverter harmonic compensation method and control device thereof |
| CN113030570A (en) * | 2021-03-22 | 2021-06-25 | 宁夏隆基宁光仪表股份有限公司 | Harmonic electric energy detection method and adaptive filter |
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