CN1018296B - Power system harmonic surveying method and instrument - Google Patents
Power system harmonic surveying method and instrumentInfo
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- CN1018296B CN1018296B CN 89105302 CN89105302A CN1018296B CN 1018296 B CN1018296 B CN 1018296B CN 89105302 CN89105302 CN 89105302 CN 89105302 A CN89105302 A CN 89105302A CN 1018296 B CN1018296 B CN 1018296B
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Abstract
The present invention belongs to a power system harmonic measuring method and a measuring and analyzing apparatus. A method of continuously providing harmonic analysis results at equal interval is utilized to measure the characteristics of time domain and frequency domain of system harmonics and quantitative statistical parameters, and harmonic current and harmonic voltage of a system are unitedly treated and analyzed to calculate a harmonic electric structure and a harmonic parameter in the system to be measured. Collected voltage and current signals are identified to eliminate interfere from the inner part and the outer part of the system. The present invention can monitor and measure system harmonics in real time on line by continuously displaying dynamic analysis results of the harmonics at equal intervals.
Description
The invention belongs to power system harmonizing wave measuring method and surveying instrument.It is applicable to the electric system and the electrical equipment of 50,60 hertz of power frequencies, below is referred to as system; Harmonic wave is meant harmonic current, harmonic voltage and harmonic impedance, below is referred to as harmonic wave.
Mostly power system harmonizing wave measuring method so far and instrument are one of random sampling or several cycles, provide the spectrum analysis result of sampled point.It is applicable to the measurement (do not change in time or seldom change) of the harmonic wave with steady character.And the harmonic wave in most cases of electric system all has complicated variation in time domain and frequency domain, and existing this measuring method and measuring instrument can not be measured the time-domain frequency-domain characteristic of harmonic wave; Individual other instrument has the harmonic wave that takes place in the measuring process of providing peaked.A kind of employing harmonic filter circuit is also arranged, the harmonic measure instrument of continuous output harmonic wave analog quantity, but its measuring accuracy is very poor, can not satisfy as accurate instrument and analyze needs.
So far power system measuring method and instrument, the harmonic current for the treatment of examining system, voltage are not carried out Measurement and analysis as system harmonics in the unified amount of time domain frequency domain, but respectively, arc on the spot provides the spectrum analysis of the electric current and the voltage of sampled point, also have to provide multiplying each other or the phase division result of sampled point harmonic voltage, current value.
Power system harmonizing wave measuring method so far and instrument, what provide is the analysis result of the full signal of sampled point, it does not distinguish the undesired signal that contains in the signal.
The goal of the invention of this power system measuring method and measuring instrument is that measuring at time-domain and frequency-domain all has the time-domain frequency-domain characteristic of the complicated Harmonious Waves in Power Systems that changes and the quantitative statistical parameter of harmonic wave; The present invention also aims to get rid of measure and disturb, improve measuring accuracy; The present invention also aims to treating examining system,, comprehensively obtain the harmonic wave electrical structure and the harmonic parameters of system harmonic current, voltage unified amount as the harmonic wave system as harmonic series unified test component analysis unified on the time-domain and frequency-domain.The present invention also aims to the harmonic wave of electric system is monitored in real time, make the operation of electric system and filter safety economy ground thereof.
Summary of the invention (one): a kind of method of measuring the time-domain frequency-domain characteristic of electric system and electrical equipment harmonic wave:
A kind of employing continuous recording system voltage and current value, equally spaced the Fourier series analysis continuously, equally spaced provide the measuring method of analysis result continuously, it can measure the harmonic wave time-domain frequency-domain characteristic of system and quantitative statistical parameter, can get rid of to measure and disturb, can make Measurement and analysis electric system to be measured.
One of the inventive method content is: existing method is a random sampling, provides the analysis result of sampled point, and the present invention adopts and equally spaced takes a sample continuously, analyzes, and equally spaced provides analysis result continuously.Thereby it can show and draw the time-domain frequency-domain characteristic curve of harmonic wave.This curve is formed curve display by equally spaced point and is printed.A kind of method that realizes equally spaced providing the frequency analysis result continuously and draw the system harmonics time-domain frequency-domain characteristic is: (a) through the electric current and the magnitude of voltage of continuous recording system, change data volume into, the application microcomputer is equally spaced sampled continuously and is carried out the Fourier series operational analysis.Be optionally equally spaced interval time, and the unit of interval time is point or second, and equally spaced minimum interval is a point, be sampled as 128 continuous samplings as one-period, doing to analyze for the first time is 1 to 128 point, and it is 2 to 129 points that the point in interval is done to analyze for the second time, and the rest may be inferred by analogy.Largest interval is not stipulated.(b) utilize graphic printer that equally spaced continuous frequency analysis result is transformed into time domain, draw the time curve of harmonic wave.That is to say, an axes of coordinates (X-axis) of graphic printer is represented time shaft, the stepping rate of time shaft is consistent with microcomputer analysis speed once, represented time interval of stepping is consistent with equally spaced interval time, the position of cursor is in direct ratio on the walking amplitude of another of graphic printer spool (Y-axis) and the display, and the analysis numerical value on the cursor tracking display, thereby Y-axis is corresponding to the amplitude of frequency analysis.(c) utilize display to show the time-domain frequency-domain characteristic of frequency analysis: allow the transverse axis of display as time shaft, the vertical pivot of display is shown the harmonic wave performance analysis result who equally spaced provides continuously corresponding to the amplitude of frequency analysis on high definition screen (CRT).
Two of the content of the inventive method is: existent method just provides the harmonic parameters of sampled point, the present invention then carries out mathematical statistics to the data that equally spaced provide certain time period among the ground frequency analysis result continuously, provides the statistical parameter of the harmonic wave in this time period.The length of time period determines as required.The long measure of time period is second.A kind of method of carrying out mathematical statistics is that the data that uniformly-spaced provide continuously in this time period are sent into microcomputer, use the conventional statistical method and the statistical content of microcomputer, count the statistical parameter of harmonic wave, for example: the harmonic wave maximal value, minimum value, mean value, the effective value that take place in this time period reach the duration, interval time, impact number of times of specific data etc.
Three of the content of the inventive method: it except keep existing measuring method the electric current for the treatment of examining system and voltage respectively (not being uniformly) measure and analysis provides the result, the inventive method is also treating that examining system is used as " black box " of the unification of unknown internal feature on the science and treats, promptly the input quantity of the harmonic current of the system of inflow as system, the output quantity of the harmonic voltage that causes in system by this ripple electric current as this system, carry out dynamically frequency analysis uniformly, provide the harmonic wave electrical structure and the multinomial harmonic parameters of internal system to be measured.A kind of dynamically harmonic analysis method of unification is with the method for asking the transport function computing, equally spaced to measure the harmonic wave electrical structure and the harmonic parameters of internal system continuously; A kind ofly be, equally spaced show the dynamic operation result to input quantity, output quantity continuously on computer display, the transverse axis of display screen provides the time-domain frequency-domain characteristic of system harmonics as time shaft, frequency axis.
Four of the content of the inventive method: existing method and instrument are samplings at random, and sample content and it are reflected that harmonic wave essence and interference can not distinguish.The inventive method is to differentiate electric current and the voltage signal gathered, identifies from the interference inside and outside the measuring system, to improve measuring accuracy.The concrete practice is from the time-domain and frequency-domain feature that equally spaced provides continuously, to get rid of the error that occurs in the interior interference of measuring system and calculate; Utilize the relevant and coherent relationships of information, identify interference from the measuring system outside.The harmonic current utilization that this method also is injected into system to the electrical equipment that harmonic current takes place is carried out harmonic measure and analysis as harmonic current source to system, utilizes the method for this discriminating measuring error to improve precision and the reliability of measuring.
Summary of the invention (two): a kind of measuring instrument of measuring electric system and electrical equipment harmonic wave.
The described method of application invention content () can design and manufacture the instrument of multiple measuring system harmonic wave.Measuring instrument for example, by the CPU microprocessor, storer, current/voltage is signal acquiring system independently, the microcomputer power system harmonic measurement instrument that analog to digital converter and corresponding software thereof constitute, it is equipped with small-sized printer, use for printing the frequency analysis result, instrument internal except have with the roughly the same general-purpose computations analysis component of current harmonic measuring instrument, special circuit and auxiliary device by the inventive method requirement also are housed, comprising graphic printer, high definition screen (CRT), statistical circuit, white noise signal generator and new control button etc.
The feature of measuring instrument one of is to be: current input terminal of harmonic measuring instrument links to each other with the harmonic current of the system of inflow, voltage input end links to each other with the harmonic voltage of system, equally spaced analyze the relation of input and output continuously, obtain internal system harmonic wave electrical structure and harmonic parameters, for example: utilize the transport function computing of being equipped with in the machine, pay upright leaf arithmetic unit and corresponding software fast, equally spaced analyze the relation of input and output continuously, just can measure the dynamic harmonic impedance of internal system, and make relevant and coherent computing.
Two of the feature of measuring instrument is: the Control Software of utilizing interior microcomputer of machine and increase, make the printing of graphic printer and the computing synchronous operation of the interior microcomputer of machine, frequency analysis result continuously equally spaced is transformed into time domain, measure the time-domain frequency-domain characteristic of system harmonics, provide the time curve of system harmonics.More particularly, be under the control of synchronizing signal, make the stepping rate of time base (X-axis) of graphic printer consistent with Microcomputer Calculation analysis speed once, and the interval time of the stepping of time shaft is consistent with selected equally spaced interval time, the drafting amplitude of another of graphic printer spool (Y-axis) and the position of the cursor on the display are in direct ratio, and numerical value is analyzed in cursor tracking, thereby Y-axis is corresponding to the frequency analysis amplitude.
The high definition screen (CRT) that uses measuring instrument to be equipped with, the transverse axis of display screen is decided to be overtone order (frequency) or time, Y-axis is the harmonic wave operation result, equally spaced the harmonic impedance of display system (dividing the relevant, relevant of other mould value, real part, imaginary part, phase place and information that shows harmonic impedance) continuously.
Utilization shows continuously equally spaced that on display screen operation result can be used as the monitor use of system harmonics real-time online, for example: the operation result of the output of display system and the transport function of input can be used as the monitor use to the harmonic impedance of system dynamics.
Three of the feature of this measuring instrument is: with the statistical circuit that is equipped with in the instrument harmonic wave time domain specification is added up, provided the statistical parameter of the harmonic wave in certain period.As: conventional statistical circuit is housed in the machine, and, counts the harmonic parameters multiple commonly used that takes place in certain the fixed time section that equally spaced provides continuously among the frequency analysis result with conventional statistical method.
The white noise signal generator also is housed in this measuring instrument, is used to measure the static characteristics of Harmonious Waves in Power Systems filter.
In addition, this measuring instrument also has new control button: transport function calculation keys, transport function computing options button (mould value, real part, imaginary part, phase place), coherent computing key, related operation key etc.
It also can carry out record with soft, hdd recorder and magnetic tape station.
The advantage of the inventive method and measuring instrument is; It can measure the time-domain frequency-domain characteristic and the statistics of system harmonics, by the measurement qualitatively of the randomness of existing method and measuring instrument, bring up to quantitative accurately measurement, its another advantage is a simple and feasible, various circuit blocks all have finished product, the parts and the circuit that do not have specific (special) requirements to make.
Description of drawings:
Accompanying drawing 1: be the electric current of method of the present invention and instrument, the connection of voltage terminal.Wherein: (a) conventional by method; Electric current, voltage are carried out frequency analysis respectively individually; (b) be newly-increased connection: promptly the input of electric current,, analyze uniformly, for example the output of voltage as system as system; In order to time domain specification of the dynamic harmonic impedance of obtaining system etc.
Accompanying drawing 2: the block scheme of measuring instrument of the present invention.Wherein, 1-graphic printer-computing machine synchro control PD; The computing of 2-microcomputer, pair upright leaf computing, transport function arithmetic section FF; 3-input signal acquisition system RC; 4-white noise signal generator CC; 5-graphic printer PR; 6-display SC; 7-statistical circuit TF.
Embodiment:
The peripherals of instrument is compared with existing universal electric power system harmonics measuring instrument, and increasing has High Resolution Display (CRT), graphic printer PR[Fig. 2 (5)] be respectively applied for demonstration, print and measure and analysis result.
The internal circuit of instrument, except that the universal circuit that still uses existing universal electric power system harmonics analyser, circuit that increases newly and control, main is that the graphic printing, the display that increase are used, and computing and control section still use existing microcomputer or calculating control system, and press to connect shown in the accompanying drawing 2 and assemble.
Calculate and graphic printing synchro control PD[Fig. 2 (1)]: still use original microcomputer to increase Control Software, the time shaft of control graphic printer and amplitude axle and COMPUTER CALCULATION are synchronous, the speed in each step of graphic printer time shaft (X-axis), consistent and synchronous operation of the time that once spends with Computer Analysis; Amplitude axle (Y-axis) amplitude of graphic printer and the cursor position of display screen are in direct ratio, and promptly amplitude is corresponding to the amplitude of frequency analysis.Connect the output of printer and microcomputer according to the international standard wiring.The selection of equally spaced interval time is realized by software.
Display SC[Fig. 2 (6)]: owing to be to be used for equally spaced showing continuously the output result, consist of curve by point, should select High Resolution Display (CRT), display is by system controlled by computer, use international standard interface, the connection of transverse axis of display (X-axis) and vertical pivot (Y-axis) is similar to the circuit of general purpose oscialloscope, and promptly its transverse axis is as time shaft or frequency axis, and vertical pivot is exported as result calculated.Display is established for multiple use at this, be used for the time-domain frequency-domain characteristic of display system harmonic wave, the harmonic parameters and the electrical structure of internal system, for example, show frequency spectrum, waveform, Lissajous-like pattern, three-dimensional plot, harmonic impedance-overtone order figure, coefficient of coherence-overtone order figure, real part of impedance, imaginary part, planimetric map etc.
Transport function computing and Fourier analysis circuit FF[Fig. 2 (2)]: this is made up of control of microcomputer software and general arithmetic unit, the content of computing is handled identical with method with information analysis commonly used, line when doing the transport function computing, be that electric current is linked to each other with its input end, voltage is connected with its output terminal, as accompanying drawing 1(b) shown in, ask transport function to provide dynamic relationship between input and output, as mould value, real part, imaginary part and the phase place etc. of harmonic impedance.
Statistical circuit TF[Fig. 2 (7)]: be general statistical circuit, the data of time-domain and frequency-domain curve are carried out conventional statistical computation, provide the quantitative statistics of harmonic wave, as harmonic wave maximal value, minimum value, mean value, the effective value that takes place in: the fixed time section, reach duration of specifying numerical value, interval time, impact number of times etc.The length of time period can decide as required.
Input signal acquisition system RC[Fig. 2 (3)]: comprise that passage switches, range switches, circuit such as sampling maintenance, analog to digital conversion constitute, and are universal circuit.
White noise signal generator CC[Fig. 2 (4)]: be to pack into individually in the machine, when the quiescent point of debugging filter, use.Sine wave, triangular signal generator based and lead-out terminal are housed in addition.
The new control button of instrument; Transport function calculation keys, transport function computing options button (mould value, real part, imaginary part, phase place), relevant operation key, related operation key etc.
All there is inner microcomputer co-ordination at each above position, and each emic switching usually is to be finished by the software of microcomputer, and show, function such as printing has switch to switch.
Can carry out record with soft, hdd recorder or magnetic tape recorder.
The harmonic wave performance analysis result that utilization equally spaced shows on display continuously, the on-line real time monitoring device that can be used as system harmonics uses.As: a kind of usage is the operation result of the output that equally spaced shows continuously with the transport function of input, as the monitor use to the harmonic impedance of system dynamics.
Claims (2)
1, a kind of power system harmonizing wave measuring method:
1.1 adopt the electric current and the magnitude of voltage of continuous recording system, change data volume into, use microcomputer and equally spaced carry out the Fourier series operational analysis harmonic wave continuously,
1.2, provide the spectrum analysis result of the voltage and current of sampling by sampling, also provide the merchant and the phase place of the harmonic voltage and the harmonic current of sampling, provide the harmonic wave maximal value that takes place in the measuring process,
1.3 system power and the voltage surveyed are sampled at synchronization, but carry out frequency analysis separately respectively,
1.4 can adopt soft, hdd recorder or magnetic tape recorder to carry out record,
It is characterized in that:
1.5 equally spaced provide the frequency analysis result continuously, measure the time-domain frequency-domain characteristic of system harmonics,
1.5.1 utilize graphic printer that equally spaced continuous frequency analysis result is transformed into time domain, draw the time curve of harmonic wave, an axes of coordinates of graphic printer is a time shaft, the stepping rate of time shaft is consistent with microcomputer analysis speed once, stepping is consistent with equally spaced interval time represented interval time, the position of cursor is in direct ratio on the walking amplitude of another of graphic printer spool and the display, and the analysis numerical value on the cursor tracking display
1.5.2 be that optionally equally spaced minimum interval is a point equally spaced interval time,
1.6 the data of certain time period among the frequency analysis result that above-mentioned (1.5) bar is equally spaced provided are continuously carried out mathematical statistics, provide the statistical parameter of harmonic wave,
1.6.1 use the conventional statistical method and the statistical content of microcomputer, count the harmonic parameters that takes place in this time period, the length of time period determines as required,
1.7 " black box " of the system of harmonic wave to be measured as the unification of scientific unknown internal feature, promptly the input quantity of the harmonic current of the system of inflow as system, the output quantity of the harmonic voltage that causes in system by this harmonic current as this system, the dynamic frequency analysis of output quantity, input quantity being unified by the method for (1.5) bar, provide the harmonic wave electrical structure and the harmonic parameters of internal system to be measured
1.7.1 equally spaced measure the harmonic wave electrical structure and the harmonic parameters of internal system continuously with the method for asking the transport function computing,
1.7.2 uniformly-spaced show continuously the dynamic operation result to the input quantity output quantity on computer display, the transverse axis of display screen provides the time-domain frequency-domain characteristic of system harmonics as time shaft or frequency axis,
1.8 differentiate to measuring electric current and the voltage signal gathered, identify from the interference inside and outside the measuring system, with the raising measuring accuracy,
1.8.1 from the time-domain and frequency-domain feature of the harmonic wave that uniformly-spaced provides continuously, get rid of the interference that occurs in the measuring system and calculate and go up the error that takes place,
1.8.2 utilize the relevant and coherent relationships of information, identify interference from the measuring system outside,
1.8.3 the harmonic current utilization that the electrical equipment that harmonic current takes place is injected into system is carried out harmonic measure and analysis as harmonic current source to system, utilizes the method for this discriminating measuring error to improve precision and the reliability of measuring.
2, the power system harmonic measurement instrument that manufactures and designs according to the described method of claim 1:
2.1 by CPU microprocessor, storer and the current/voltage computerized measurement instrument that constitutes of signal acquiring system, analog to digital converter and corresponding software thereof independently,
2.2 the small-sized printer of printing sampling ripple frequency analysis result is housed,
2.3 voltage input end and current input terminal are arranged, voltage, electric current are measured and the circuit of spectrum analysis respectively,
2.4 be useful on soft, the hdd recorder or the magnetic tape recorder of record,
It is characterized in that:
2.5 the current input terminal that links to each other with the harmonic current of the system of inflow, the voltage input end that links to each other with the harmonic voltage of system are arranged, the relation of equally spaced analyzing continuously between its input quantity and output quantity, the circuit of obtaining internal system harmonic wave electrical structure and harmonic parameters are arranged
2.5.1 can be equally spaced continuous analysis input and output relation is housed in the machine, measures the dynamic harmonic impedance of internal system and does the transport function computing of relevant and coherent computing, pay upright leaf arithmetic unit and corresponding software fast,
2.6 have the microcomputer in the printing that makes graphic printer and the machine computing synchronous operation, equally spaced continuous frequency analysis result be transformed into time domain, measure system harmonics time-domain frequency-domain characteristic, provide the synchro control of the time curve of system harmonics,
2.6.1 graphic printer is arranged, its axes of coordinates is a time shaft, the stepping rate of time shaft is consistent with Microcomputer Calculation analysis speed once, the stepping of time shaft is consistent with selected equally spaced interval time represented interval time, in the graphic printer on the drafting amplitude of an axle and the display position of cursor in direct ratio, and numerical value is analyzed in cursor tracking
2.6.2 high definition screen is housed, and its transverse axis is decided to be overtone order or time, the harmonic impedance of the system that its vertical pivot is the harmonic wave operation result, equally spaced show continuously,
2.7 the statistical circuit of the harmonic wave time domain specification being added up, provided the harmonic wave statistical parameter is housed,
2.7.1 the statistical circuit with the routine of the harmonic parameters that takes place in conventional statistical method, equally spaced certain the fixed time section that provides continuously of statistics is housed in the machine,
2.8 new control button is arranged: transport function calculation keys, transport function computing options button, coherent computing key, related operation key,
2.9 the white noise signal generator of the static characteristics that is used to measure the Harmonious Waves in Power Systems filter is housed in the instrument,
2.10 utilize the harmonic wave performance analysis result who on display, equally spaced shows continuously, as the on-line real time monitoring device use of system harmonics,
2.10.1 equally spaced demonstrate the transport function operation result of the output and the input of system continuously, use as monitor to the system dynamics harmonic impedance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 89105302 CN1018296B (en) | 1989-05-30 | 1989-05-30 | Power system harmonic surveying method and instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 89105302 CN1018296B (en) | 1989-05-30 | 1989-05-30 | Power system harmonic surveying method and instrument |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1046982A CN1046982A (en) | 1990-11-14 |
| CN1018296B true CN1018296B (en) | 1992-09-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 89105302 Expired CN1018296B (en) | 1989-05-30 | 1989-05-30 | Power system harmonic surveying method and instrument |
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| CN (1) | CN1018296B (en) |
Cited By (1)
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| CN101900761B (en) * | 2009-11-05 | 2012-08-22 | 中国航天科技集团公司第五研究院第五一四研究所 | High-accuracy non-integer-period sampled harmonic analysis and measurement method |
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| CN105429304B (en) * | 2015-12-31 | 2018-05-25 | 国家电网公司 | The method being monitored to the harmonic source of power grid |
| CN105974196B (en) * | 2016-06-14 | 2018-08-17 | 吉林大学 | A kind of high-precision power grid harmonic measure system and method |
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-
1989
- 1989-05-30 CN CN 89105302 patent/CN1018296B/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101441231B (en) * | 2008-09-27 | 2010-06-23 | 武汉大学 | Harmonic electric energy metering error analytical apparatus |
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| Publication number | Publication date |
|---|---|
| CN1046982A (en) | 1990-11-14 |
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