CN105116202A - Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes - Google Patents

Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes Download PDF

Info

Publication number
CN105116202A
CN105116202A CN201510408318.8A CN201510408318A CN105116202A CN 105116202 A CN105116202 A CN 105116202A CN 201510408318 A CN201510408318 A CN 201510408318A CN 105116202 A CN105116202 A CN 105116202A
Authority
CN
China
Prior art keywords
amplitude
primitive period
square wave
harmonic
electric signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201510408318.8A
Other languages
Chinese (zh)
Inventor
邵武
郭伟
周伟
张贵鹏
徐宏
李雪梅
穆亚明
白霖
赵静
翟亮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yuxi Power Supply Bureau of Yunnan Power Grid Co Ltd
Original Assignee
Yuxi Power Supply Bureau of Yunnan Power Grid Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yuxi Power Supply Bureau of Yunnan Power Grid Co Ltd filed Critical Yuxi Power Supply Bureau of Yunnan Power Grid Co Ltd
Priority to CN201510408318.8A priority Critical patent/CN105116202A/en
Publication of CN105116202A publication Critical patent/CN105116202A/en
Pending legal-status Critical Current

Links

Abstract

A method of rapidly obtaining an electric signal fundamental wave amplitude and multiple harmonic amplitudes comprises the following steps of detecting the fundamental wave cycles of a tested electric signal; acquiring the tested electric signal of at least one fundamental wave cycle; according to the fundamental wave cycles, generating two sets of mutually orthogonal multiple rectangular waves of 1/X times of fundamental wave cycle, wherein X is a positive integer greater than 1; selecting N sampling signals in at least one fundamental wave cycle to multiply the two sets of orthogonal multiple rectangular waves respectively and summing, wherein N is a positive integer; obtaining the fundamental wave amplitude and the X-th harmonic amplitude respectively according to a first rectangular wave rule and an X-th rectangular wave rule.

Description

A kind of method of quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude
Technical field
The present invention relates to Electric signal processing method, particularly relate to a kind of method of quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude.
Background technology
Current most widely used signal transacting processes electric signal.Usually comprise first-harmonic, harmonic wave and m-Acetyl chlorophosphonazo aliquot in electric signal, these different components have different amplitudes, frequency and initial phase.Different components carries different information, by processing this electric signal, extracting different components, can obtain corresponding information.In recent years, due to the develop rapidly of Power Electronic Technique, the application of various power electronic equipment in electric system, industry, traffic and family is increasingly extensive, and the harm that harmonic wave, m-Acetyl chlorophosphonazo cause is day by day serious.The measurement of harmonic wave, m-Acetyl chlorophosphonazo is the basis of wave form distortion analysis, harmonic source analysis, mains by harmonics Load flow calculation, harmonic compensation and suppression.
Frequency analysis technology is widely used in various fields such as electric energy quality monitoring, electronic product production testing, electric appliances monitoring, is the important technical of carrying out power system monitor, quality inspection, monitoring of tools.
The main method of Measurement of Harmonics in Power System has: based on harmonic detecting, the harmonic detecting based on instantaneous reactive power, the harmonic detecting based on Fourier transform, the harmonic detecting based on neural network, the harmonic detecting based on wavelet transformation of analog bandpass or rejection filter.
Present most widely used harmonic detecting method is the harmonic detecting method based on Fourier transform.In the harmonic detecting of stable state, it is higher that the harmonic detecting method based on Fourier transform has precision, and function is more, easy to use, is easy to the advantages such as realization.
But, high-precision harmonic detecting at present based on Fourier transform scheduling theory all needs complicated computing method to support, and calculated amount is large, and needs high performance hardware, chip support, as DSP at a high speed, cause detection time slow, volume is large, and cost is high, Maintenance Difficulty, the shortcomings such as portability difference, do not need at some the occasion accurately measuring harmonic content, engineer applied does not have practicality.
Summary of the invention
Based on this, the application proposes a kind of method of quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude, the fundamental voltage amplitude of quick calculating current, voltage and multiple harmonic amplitude, and the method calculated amount is little, hardware design only needs single-chip microcomputer just can complete, have speed fast, volume is little, and structure is simple, the feature such as portable, not needing accurately to measure first-harmonic, harmonic amplitude, only needing the place of ordinary surveying first-harmonic and multiple harmonic amplitude, engineering request for utilization can be met.
A method for quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude, it comprises the steps:
Detect the primitive period of tested electric signals;
Gather the tested electric signals of at least one primitive period;
According to the primitive period, generate the mutually orthogonal repeatedly square wave of two groups of 1/X times of primitive periods, wherein X be greater than 1 positive integer;
The N number of sampled signal repeatedly square wave orthogonal with two groups chosen at least one primitive period is multiplied respectively and sues for peace, and wherein N is positive integer;
The amplitude of first-harmonic and X subharmonic is obtained respectively according to a square wave rule and X square wave rule.
Wherein in an embodiment, described in the N number of sampled signal repeatedly square wave orthogonal with two groups chosen at least one primitive period be multiplied respectively in the step of suing for peace, the selected primitive period is a primitive period.
Wherein in an embodiment, in the step of the tested electric signals of described at least one primitive period of collection, the primitive period gathered is a primitive period.
Wherein in an embodiment, the step of the primitive period of described detection tested electric signals detects the primitive period by the method for detection tested electric signals successive zero-crossings.
Wherein in an embodiment, described according to the primitive period, generate in the step of mutually orthogonal repeatedly square wave of two groups of 1/X times of primitive periods, X is 3.
The method of above-mentioned acquisition electric signal fundamental voltage amplitude and multiple harmonic amplitude is compared to traditional half-wave rectification fundamental voltage amplitude acquisition methods, and the method for the application has the following advantages:
(1) first-harmonic and multiple harmonic amplitude can be calculated fast simultaneously.
(2) acquisition methods is simple, be multiplied with measured signal by the repeatedly square wave of generating orthogonal, namely be that the cumulative summation of segmentation is carried out to measured signal, obtain measured signal subsection integral value, simple addition and multiplication several times is only needed to complete computing, computing velocity is fast, and Programming is simple.
(3) two groups of orthogonal three square waves are utilized to modulate, without the need to considering repeatedly the phase equalization problem of square wave and multiple harmonic, first-harmonic.
(4) utilize repeatedly square wave to be multiplied with sampled signal to sue for peace the storage values of pilot process, namely segmentation add up summation obtain measured signal subsection integral value, it is reconfigured, fundamental voltage amplitude can be calculated simultaneously, with only to obtain the multiple harmonic amplitude time substantially the same, save operation time.
(5) because computing is simple, hardware requirement is not high, is easy to single-chip microcomputer realizes, and can effectively reduce device volume and cost.
Accompanying drawing explanation
Fig. 1 is the method flow diagram of acquisition electric signal fundamental voltage amplitude of the present invention and multiple harmonic amplitude;
Fig. 2 is given sinusoidal signal and the square wave schematic diagram with its same frequency;
Fig. 3 is orthogonal square wave schematic diagram corresponding to sinusoidal signal.
Embodiment
Please refer to Fig. 1, better embodiment of the present invention provides a kind of method of quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude.The method of this electric signal fundamental voltage amplitude and multiple harmonic amplitude is based on repeatedly square wave quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude.It comprises the steps:
Step S110, detects the primitive period of tested electric signals.
Step S120, gathers the tested electric signals of at least one primitive period.In order to less calculated amount, the electric signal of a primitive period can be taked when reality uses.
Step S130, according to the primitive period, generates the mutually orthogonal repeatedly square wave of two groups of 1/X times of primitive periods, wherein X be greater than 1 positive integer.
Step S140, the N number of sampled signal repeatedly square wave orthogonal with two groups chosen at least one primitive period is multiplied respectively and sues for peace, and wherein N is positive integer.In order to less calculated amount, the electric signal of a primitive period can be chosen when reality uses.
Step S150, obtains the amplitude of first-harmonic and X subharmonic respectively according to a square wave rule and X square wave rule.
Electric signal is generally sinusoidal signal or cosine signal.For given sinusoidal signal A msin (ω t), its integration in half period to the integration of digital sinusoidal signal in half period when converting digital signal to, being cumulative summation:
wherein t is the sinusoidal signal cycle, N and i is natural number, and sampled point N is larger, and y ' is more close to y.
The given square wave with sinusoidal signal same frequency, as shown in Figure 2, square wave dutycycle is 50%, true amplitude is 1, negative amplitude is-1, be multiplied with measured signal with the square wave of same frequency, namely the sinusoidal signal converting digital signal to sued for peace by square wave rule is cumulative within the whole cycle, obtain measured signal integrated value:
y ′ ′ = 2 π 2 N ( Σ i = 1 N A m s i n ( ωt i ) - Σ i = N + 1 2 N A m s i n ( ωt i ) ) ≈ 4 A m , Wherein t i = i T 2 N , T is the sinusoidal signal cycle, and sampled point N is larger, and y is " more close to 4A m.
According to above-mentioned principle, be multiplied with same frequency square wave with fundamental frequency sine wave, namely the cumulative summation of segmentation carried out to measured signal, try to achieve sinusoidal wave integrated value, thus obtain sinusoidal magnitude A m.When measured signal also contains harmonic wave except first-harmonic, result of calculation contains harmonic amplitude, but harmonic content is less, negligible when not needing accurate Calculation, in this, as fundamental voltage amplitude.
When measured signal contains and mainly contains some multiple harmonics (such as third harmonic), be multiplied with three square waves with measured signal, namely measured signal is added up by three square wave rules within the whole cycle and sue for peace, obtain measured signal integrated value, can in the hope of three in measured signal time and higher hamonic wave amplitude composition, and not containing fundamental voltage amplitude composition, ignore less higher hamonic wave amplitude, namely obtain third harmonic amplitude.
When considering measured signal and square wave phase problem, if measured signal and square wave phase place inconsistent, now be multiplied with measured signal respectively with two groups of orthogonal square waves, namely the cumulative summation of segmentation is carried out to measured signal, obtain measured signal subsection integral value, obtain two groups of results and be designated as M1, M2, then first-harmonic or harmonic amplitude are: M = M 1 2 + M 2 2 .
The method of the acquisition of fundamental voltage amplitude and third harmonic amplitude is introduced below for fundamental voltage amplitude and third harmonic amplitude.Below just illustrate introduction, the art personnel are understandable that this acquisition methods also may be used for the acquisition of other harmonic amplitude, such as 4 subharmonic amplitudes or 5 subharmonic amplitudes.
First primitive period detection can be carried out to tested electric signals when obtaining fundamental voltage amplitude and third harmonic amplitude.The primitive period is detected by detecting tested electric signals successive zero-crossings.Primitive period is for generating two groups of orthogonal three square wave modulation signals.Three square-wave signals refer to that the cycle is the primitive period square wave of 1/3 times.
Carry out sampling to tested electric signals to go forward side by side line number mode convertion.By the primitive period of measured signal, ensure the data at least sampling a primitive period, be located at the N number of point of sampling in the primitive period, measured signal is f (t), then the signal value sequence generated of sampling is f (k), k=1,2 ... N.Wherein, N is positive integer.
According to primitive period T, generate three square waves of two groups of 1/3 times of primitive periods.Two groups of square wave dutycycles are 50%, and true amplitude is 1, and it is orthogonal that negative amplitude is-1, two groups of square waves, phase differential 90 degree.Be designated as Y1 respectively, Y2.Two groups that generated orthogonal three square wave modulation signals as shown in Figure 3.
Herein without the need to considering the phase place consensus of three square waves and measured signal first-harmonic, third harmonic, three the square wave phase places namely generated may be different from measured signal third harmonic phase place, do not affect testing result.
Three times orthogonal with two groups for sampled signal square waves are multiplied respectively and sue for peace, namely the cumulative summation of segmentation is carried out to tested electric signals, obtain measured signal subsection integral value, thus obtain first-harmonic and third harmonic amplitude.Third harmonic amplitude and fundamental voltage amplitude can be obtained respectively in two steps herein.
1) third harmonic amplitude is calculated.
Sampled signal f (k) is multiplied with square wave Y1 sue for peace (i.e. accumulating operation), ask first-harmonic and third harmonic amplitude for convenience of using pilot process calculated value simultaneously, point segment record adds up summing value, obtain measured signal subsection integral value, be designated as A1, A2, A3, A4, A5, A6 respectively, wherein A 2 = - Σ k = N / 6 + 1 N / 3 f ( k ) , A 3 = Σ k = N / 3 + 1 N / 2 f ( k ) , A 4 = - Σ k = N / 2 + 1 2 N / 3 f ( k ) , A 5 = Σ k = 2 N / 3 + 1 5 N / 6 f ( k ) , A 6 = - Σ k = 5 N / 6 + 1 N f ( k )
Sampled signal f (k) is multiplied with square wave Y2 sue for peace (i.e. accumulating operation), ask first-harmonic and third harmonic amplitude for convenience of using pilot process calculated value simultaneously, point segment record adds up summing value, obtain measured signal subsection integral value, be designated as B1, B2, B3, B4, B5, B6 respectively, B7, wherein
B 1 = Σ k = 1 N / 12 f ( k ) , B 2 = - Σ k = N / 12 + 1 N / 4 f ( k ) , B 3 = Σ k = N / 4 + 1 5 N / 12 f ( k ) , B 4 = - Σ k = 5 N / 12 + 1 7 N / 12 f ( k ) , B 5 = Σ k = 7 N / 12 + 1 3 N / 4 f ( k ) , B 6 = - Σ k = 3 N / 4 + 1 11 N / 12 f ( k ) , B 7 = Σ k = 11 N / 12 + 1 N f ( k ) .
Make M 31=A1+A2+A3+A4+A5+A6
M 32=B1+B2+B3+B4+B5+B6+B7。
Then, M 31for sampled signal f (k) to be multiplied with square wave Y1 summed result, be measured signal subsection integral value by three square wave Y1 rule combined result, M 32for sampled signal f (k) to be multiplied with square wave Y1 summed result, be measured signal subsection integral value by three square wave Y2 rule combined result, ignore less higher hamonic wave amplitude composition, third harmonic amplitude is:
M 3 = π 2 N M 31 2 + M 32 2
2) fundamental voltage amplitude is calculated.
Needing is multiplied to sue for peace with measured signal sampled value with two groups of orthogonal square waves obtains measured signal first-harmonic integrated value.Obtain because a square wave can be combined by three square waves, therefore utilize above-mentioned record subsection integral value A, B, fundamental voltage amplitude can be calculated simultaneously.
Make M 11=A1-A2+A3+A4-A5+A6
M 12=B1-B2-B3+B4-B5-B6+B7
Then, result C1, D1 are equivalent to the result that two groups of orthogonal square waves are multiplied with sampled signal, and namely measured signal is by the integrated value of a square wave rule combination, and ignore less harmonic amplitude composition, fundamental voltage amplitude is:
M 1 = π 2 N M 11 2 + M 12 2 .
So just obtain fundamental voltage amplitude and the third harmonic amplitude of tested electric signals.
By obtain above electric signal fundamental voltage amplitude and multiple harmonic amplitude method we can see, the method for the application has the following advantages:
(1) first-harmonic and multiple harmonic amplitude can be calculated fast simultaneously.
(2) acquisition methods is simple, be multiplied with measured signal by the repeatedly square wave of generating orthogonal, namely be that the cumulative summation of segmentation is carried out to measured signal, obtain measured signal subsection integral value, simple addition and multiplication several times is only needed to complete computing, computing velocity is fast, and Programming is simple.
(3) two groups of orthogonal three square waves are utilized to modulate, without the need to considering repeatedly the phase equalization problem of square wave and multiple harmonic, first-harmonic.
(4) utilize repeatedly square wave to be multiplied with sampled signal to sue for peace the storage values of pilot process, namely segmentation add up summation obtain measured signal subsection integral value, it is reconfigured, fundamental voltage amplitude can be calculated simultaneously, with only to obtain the multiple harmonic amplitude time substantially the same, save operation time.
(5) because computing is simple, hardware requirement is not high, is easy to single-chip microcomputer realizes, and can effectively reduce device volume and cost.
The above embodiment only have expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (5)

1. a method for quick obtaining electric signal fundamental voltage amplitude and multiple harmonic amplitude, is characterized in that, comprises the steps:
Detect the primitive period of tested electric signals;
Gather the tested electric signals of at least one primitive period;
According to the primitive period, generate the mutually orthogonal repeatedly square wave of two groups of 1/X times of primitive periods, wherein X be greater than 1 positive integer;
The N number of sampled signal repeatedly square wave orthogonal with two groups chosen at least one primitive period is multiplied respectively and sues for peace, and wherein N is positive integer;
The amplitude of first-harmonic and X subharmonic is obtained respectively according to a square wave rule and X square wave rule.
2. the method for quick obtaining electric signal fundamental voltage amplitude according to claim 1 and multiple harmonic amplitude, it is characterized in that, the described N number of sampled signal chosen at least one primitive period repeatedly square wave orthogonal with two groups is multiplied in the step of suing for peace respectively, and the selected primitive period is a primitive period.
3. the method for quick obtaining electric signal fundamental voltage amplitude according to claim 2 and multiple harmonic amplitude, is characterized in that, in the step of the tested electric signals of described at least one primitive period of collection, the primitive period gathered is a primitive period.
4. the method for quick obtaining electric signal fundamental voltage amplitude according to claim 1 and multiple harmonic amplitude, it is characterized in that, the step of the primitive period of described detection tested electric signals detects the primitive period by the method for detection tested electric signals successive zero-crossings.
5. the method for quick obtaining electric signal fundamental voltage amplitude according to any one of claim 1 to 4 and multiple harmonic amplitude, it is characterized in that, described according to the primitive period, generate in the step of mutually orthogonal repeatedly square wave of two groups of 1/X times of primitive periods, X is 3.
CN201510408318.8A 2015-07-14 2015-07-14 Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes Pending CN105116202A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510408318.8A CN105116202A (en) 2015-07-14 2015-07-14 Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510408318.8A CN105116202A (en) 2015-07-14 2015-07-14 Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes

Publications (1)

Publication Number Publication Date
CN105116202A true CN105116202A (en) 2015-12-02

Family

ID=54664238

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510408318.8A Pending CN105116202A (en) 2015-07-14 2015-07-14 Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes

Country Status (1)

Country Link
CN (1) CN105116202A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114062938A (en) * 2020-07-29 2022-02-18 比亚迪股份有限公司 Method and device for detecting oscillation heating current of power battery and vehicle

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000180484A (en) * 1998-12-18 2000-06-30 Nissin Electric Co Ltd Apparatus for measuring harmonic wave
CN102621382A (en) * 2012-03-22 2012-08-01 清华大学 Method for detecting frequency, phase and amplitude of electric signal in electric power system
CN102998527A (en) * 2012-11-26 2013-03-27 上海电力学院 Pass band type fundamental wave, harmonic wave and direct current component detection method
CN103543331A (en) * 2013-10-24 2014-01-29 佟晓白 Method for calculating harmonics and inter-harmonics of electric signal
CN103983849A (en) * 2014-05-07 2014-08-13 江苏天浩达科技有限公司 Real-time high-accuracy power harmonic analysis method
CN104502675A (en) * 2014-12-29 2015-04-08 广东电网有限责任公司电力科学研究院 Fundamental wave amplitude method and system of power signal
CN104502706A (en) * 2014-12-29 2015-04-08 广东电网有限责任公司电力科学研究院 Harmonic amplitude measurement method and system of power signal

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000180484A (en) * 1998-12-18 2000-06-30 Nissin Electric Co Ltd Apparatus for measuring harmonic wave
CN102621382A (en) * 2012-03-22 2012-08-01 清华大学 Method for detecting frequency, phase and amplitude of electric signal in electric power system
CN102998527A (en) * 2012-11-26 2013-03-27 上海电力学院 Pass band type fundamental wave, harmonic wave and direct current component detection method
CN103543331A (en) * 2013-10-24 2014-01-29 佟晓白 Method for calculating harmonics and inter-harmonics of electric signal
CN103983849A (en) * 2014-05-07 2014-08-13 江苏天浩达科技有限公司 Real-time high-accuracy power harmonic analysis method
CN104502675A (en) * 2014-12-29 2015-04-08 广东电网有限责任公司电力科学研究院 Fundamental wave amplitude method and system of power signal
CN104502706A (en) * 2014-12-29 2015-04-08 广东电网有限责任公司电力科学研究院 Harmonic amplitude measurement method and system of power signal

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
张文博等: "一种基于正交三角级数神经网络的谐波检测方法", 《电力系统及其自动化学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114062938A (en) * 2020-07-29 2022-02-18 比亚迪股份有限公司 Method and device for detecting oscillation heating current of power battery and vehicle
CN114062938B (en) * 2020-07-29 2022-08-09 比亚迪股份有限公司 Method and device for detecting oscillation heating current of power battery and vehicle

Similar Documents

Publication Publication Date Title
CN103869162B (en) Dynamic signal phasor measurement method based on time domain quasi-synchronization
CN101806832B (en) Measuring method for frequencies of low-frequency signals
CN102288821B (en) Measuring method, measuring device, measuring procedure and carrier for phase difference of three-phase circuit
CN101509945B (en) Real-time detection method for positive and negative sequence electricity quantity
CN105319447B (en) A kind of dielectric loss angle tangent method of testing and tester
CN103217578B (en) Based on digital phasemeter and the method thereof of phase differential between PHASE-LOCKED LOOP PLL TECHNIQUE measuring-signal
Dash et al. Dynamic phasor and frequency estimation of time-varying power system signals
CN203287435U (en) A micro electrical network harmonic wave and inter-harmonic wave test apparatus based on an STM32F107VCT6
CN109633262A (en) Three phase harmonic electric energy gauging method, device based on composite window multiline FFT
CN102809687B (en) Digital measurement method for alternating-current frequency
CN105676008A (en) Digital electric field sensor
CN102221639A (en) Positive and negative sequence current real-time detection method
CN104849552A (en) Adaptive-notch-filter-based harmonic wave extraction method
CN106483375B (en) A kind of multi-frequency fractional harmonic wave detection method
CN103383413A (en) Real-time harmonic detection method based on direct weight determination method
CN105116202A (en) Method of rapidly obtaining electric signal fundamental wave amplitude and multiple harmonic amplitudes
CN103364634B (en) Three-phase alternating-current supply frequency measurement method
CN103575981A (en) Method for accurately measuring alternating current frequency
CN103176030A (en) Method for detecting inter-harmonics of power distribution system
CN105911350A (en) Adaptive recursive frequency SVFT harmonic sequence component real-time detection method and system
CN103576120B (en) Third-harmonic component plesiochronous information transfer check and Self-healing Algorithm
CN105842536A (en) Improved ZoomFFT and ApFFT algorithm integrated method for analyzing dense harmonics and inter-harmonics
CN102323481A (en) Measuring apparatus for unstable harmonics and interharmonics
Tiwari et al. Measurement of Instantaneous Power Quality Parameters Using UWPT and Hilbert Transform and Its FPGA Implementation
Jianhua et al. Study on the current detecting method for reactive power and harmonic of the three-phase circuits

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20151202