CN1462886A - Digital method for measuring real effective value of AC electric auqntity - Google Patents
Digital method for measuring real effective value of AC electric auqntity Download PDFInfo
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Abstract
A digital method for measuring the true effective value of AC parameter features that the calculation module, A/D filter and prefilter are used to acquire the data needed by said measuring, and three invented equations are used to calculate said true effective value of each cycle.
Description
Technical field
The invention belongs to the ac electric quantity measuring technical field, be specifically related to a kind of ac electric real effective digital measuring method.It is particularly useful for the measurement of power frequency ac voltage in the electric system, alternating current.
Background technology
Digital measuring method is meant that using A/D converter (analog/digital converter) is digital signal with tested analog signal conversion, by digital signal is carried out the measuring method that calculation process obtains measurement result; Ac electric can be alternating voltage, alternating current etc.
Utilizing the effective value of the ac electric of Digital Measuring Technique offset of sinusoidal form accurately to measure tool has very important significance.Effective value is meant the root mean square value of ac electric in one-period by its definition, is with equation expression
X in the formula (t) is an ac electric; X
EffEffective value for correspondence; T is the time; T is the cycle of ac electric; Sqr () represents the root of making even.(1) effective value that provides of formula has comprised the effective value of first-harmonic and harmonic wave, is both common contributions.In electric system, thisly be called as real effective with the effective value that the harmonic wave mutual group becomes by first-harmonic, be also sometimes referred to as the root mean square value.
For digital measuring system, (1) formula becomes X
Eff=sqr ((x
m 2(T
s) T
s+ x
m 2(2T
s) T
s+ x
m 2(3T
s) T
s+ ...+x
m 2(NT
s) T
s)/NT
s)
=sqr ((x
m 2(1)+x
m 2(2)+x
m 2(3)+...+x
m 2(N)) T in (2) formula/N)
sBe the sampling period of measuring system; X (kT
s) and x (k) be that ac electric is at kT
sSampled value constantly (k=1,2 ..., N); N is sampling number or the sampling number in the ac electric one-period.(2) value that provides of formula also is a real effective.
There are three kinds of digital measuring methods to measure the effective value of ac electric at present: peak value measurement method, measurement of average value method and calculating mensuration.Peak value measurement method and mean value mensuration at first measure the peak value or the mean value of pure sinusoid ac electric, utilize the definite relation between peak value or mean value and the effective value to calculate effective value then.The common drawback of these two kinds of methods is that they can only be used to not have the pure sinusoid signal occasion of harmonic wave, having under the situation of harmonic wave, the relation of the relation of peak value and effective value and mean value and effective value all is difficult to determine, can produce very big measuring error, so the value that they record is not that real effective (is seen " China Power encyclopedia ", China Electric Power Publishing House, the 2nd edition, calendar year 2001, Beijing, 217 pages, 323 pages).Different with top two kinds of methods, calculate mensuration and can be used for the occasion that harmonic wave exists.This method utilization (2) formula is calculated, and therefore can record real effective.But for guaranteeing the correctness of (2) formula result of calculation, work hours the word measuring system except that must satisfying general condition such as Shannon sampling rule grade, also must satisfy integer-period sampled condition
NT
s=T, (n is integer or rational fraction) (3) are must equal the integral multiple in sampling period or rational fraction the cycle of ac electric doubly.As not satisfying integer-period sampled condition, the value of trying to achieve with (2) formula does not just meet the definition of the real effective that (1) formula provides, and (sees Hu Guangshu thereby produce measuring error, " digital signal processing ", publishing house of Tsing-Hua University, the 1st edition, 1997, Beijing, 93 pages to 94 pages).Therefore using when calculating mensuration and measuring effective value, measurement must be divided into for two steps and carry out.At first measure the period T of current cycle, (3) formula of utilization is calculated sampling period T
s, with this sampling period the effective value of next cycle is measured calculating then.Such metering system can produce following problem: the first, and the integer-period sampled hardware that needs to adopt as phaselocked loop, and additional corresponding software is realized.This makes system bulk increase, and it is complicated that structure becomes; The second, in the real work cycle of the cycle of current cycle and next cycle not necessarily identical, therefore the effective value of the next cycle that goes out according to the computation of Period of current cycle is inaccurate.Considering to calculate needs the time, some mini-system even could use this period T will wait until again next cycle the time
sSampling, time delay just reaches two cycle period like this, and this can further strengthen measuring error; The 3rd, be subjected to the restriction of word length and computer operation frequency, in fact integer-period sampled condition is difficult to reach fully, and the accuracy of measuring system is affected.This is especially obvious in the less measuring system of being made up of microprocessor.
Summary of the invention
The purpose of this patent is to provide a kind of new ac electric real effective digital measuring method, this method had both kept the calculating mensuration and can be used for having this advantage of harmonic wave occasion, removed simultaneously integer-period sampled this restrictive condition of traditional calculations mensuration requirement again, integer-period sampled above-mentioned three shortcomings of bringing have been eliminated, and can achieve simplified, measuring accuracy improves.
A kind of ac electric real effective digital measuring method of the present invention is provided with array storage unit down at data-carrier store: A unit: last data of depositing a last cycle; B unit: the last sampled data of depositing current cycle; C unit: the current sampled data of depositing current cycle; D unit: the sampling number of depositing current cycle; E unit: deposit accumulated value; ζ unit: deposit (5) formula result of calculation; η unit: deposit (6) formula result of calculation; With the high frequency clutter elimination in the tested AC signal, send into A/D converter; Its measuring process is: (1), startup A/D converter are sampled to the 1st cycle, and the sampled value that obtains for the first time is x
1(1), makes B
=x
1(1); (2), by constant sampling period T
sStart A/D converter, continue the sampling of the 1st cycle is obtained sampling
Value x
1(2); (3), make C=x
1(2), judge x
1(2) whether be positive signal or zero-signal, if not, make B=x
1(2),
Enter step 4.; If then further judge x
1(1) whether be negative signal, if not, B=then
x
1(2), enter step 4., if enter step 5.; (4), repeating step 2. with step 3., continue tested AC signal sampling is obtained sampled value successively
x
1(3), x
1(4), x
1(5), (5), make A=x
1(N
1), B=x
2(1), D=1 utilizes formula (5) formula to calculate ζ
2, make ζ=ζ
2, E=x
2 2(1) ζ
2, establish j=2; (6), enter j cycle, A=x at this moment
J-1(N
J-1), B=x
j(1), C=x
j(1), D=1, E=x
j 2(1)
ζ
j, (7), continuation are by constant sampling period T
sStart A/D converter,, get hits the sampling of j cycle
According to x
j(2); (8), make C=x
j(2), computing module is judged x
j(2) whether be positive signal or zero-signal, if not, order
E=(E)+x
j 2(2), D=(D)+1, B=x
j(2), arrive step (9) afterwards; If then advance one
Step is judged the x in the B unit
j(1) whether is negative signal, if not, then makes E=(E)+x
j 2(2),
D=(D)+1, B=x
j(2), arrive step (9) afterwards, if enter step (10); (9), repeating step (7) and step (8), successively subsequent sampling data x
j(3), x
j(4) ..., whenever adopt
A data x
j(k), k=3,4 ..., make C=x
jAnd judge x (k),
j(k) whether be positive signal or
Zero-signal, if not, E=(E)+x then
j 2(k), D=(D)+1, B=x
j(k), arrive the step afterwards
Suddenly 8.; If then further judge the x in the B unit
j(k-1) whether be negative signal, if not,
Then make E=(E)+x
j 2(k), D=(D)+1, B=x
j(k), get back to step (9) afterwards, if,
Enter step (10); (10) Ci Shi sampled value is x
J+1And B=x (1),
j(N
j), calculate η according to (6) formula
j, and make η=
η
j, obtain the real effective of j cycle according to (4) formula again; (11), make A=x
j(N
j), B=x
J+1(1), D=1 calculates ζ according to (5) formula
J+1, make ζ
=ζ
J+1, E=x
J+1 2(1) ζ
J+1(12), make j=j+1, repeating step (7) is to step (11), successively to the cycle of the postorder meter of sampling
Calculate, until the real effective that obtains required each cycle;
X wherein
Eff=(x
m 2(1) ζ
mT
s+ x
m 2(2) T
s+ x
m 2(3) T
s+ ...+x
m 2(N
m) T
s/ (N
m-1) T
s+ (ζ
m+ η
m) T
s)
＝(x
m 2(1)ζ
m+x
m 2(2)+x
m 2(3)+...+x
m 2(N
m))/(N
m-1+ζ
m+η
m)，
(m＝2，3，4，…)??????????????????????(4)ζ
m＝x
m(1)/(x
m(1)+|x
m-1(N
m-1)|)????????????????????????????(5)η
m＝|x
m(N
m)|/(x
m+1(1)+|x
m(N
m)|)??????????????????????????(6)。
This method has following characteristics: 1, this method can be measured the real effective of ac electric, and no matter whether it has harmonic wave to exist; 2, calculate effective value because of this method adopts (4) formula, computation process does not need to use the frequency or the cycle of tested ac electric, so this method is not subjected to the restriction of integer-period sampled condition (3) formula, has eliminated the integer-period sampled shortcoming of bringing.This makes whole simplified, and volume reduces, and measuring accuracy improves; 3, because of this method is not a first survey cycle post-sampling, but Direct Sampling calculating, so can draw its effective value at each cycle in the past, can not surpass a cycle time delay.So can continuously export each real effective of past cycle just with this method; Have good tracing property and real-time; 4, adopt this method can when measuring real effective, attach the frequency values of measuring AC signal.
The method of the invention is mainly used in the measurement of power frequency ac voltage in the electric system, alternating current real effective.Because measurement mechanism of the present invention is simple in structure, therefore be particularly suitable for adopting the occasion of the small-sized or miniature digital measuring device of embedded or chip microprocessor.
Description of drawings
Fig. 1 is a kind of system architecture synoptic diagram that adopts the inventive method.
Embodiment
Below the present invention is further detailed explanation.
System is with constant sampling period T
sSampling, and no matter whether it satisfies the integer-period sampled condition that (3) formula provides.If current cycle be the m cycle (m=2,3,4 ...), during this cycle in, adopt altogether N
mIndividual value x
m(1), x
m(2) ..., x
m(N
m), x wherein
m(1) 〉=0, x
m(N
m)＜0.And last sampled value of a last cycle (m-1 cycle) is x
M-1(N
M-1), first sampled value of next cycle (m+1 cycle) is x
M+1(1), be X then corresponding to the real effective computing formula of current cycle
Eff=(x
m 2(1) ζ
mT
s+ x
m 2(2) T
s+ x
m 2(3) T
s+ ...+x
m 2(N
m) T
s/ (N
m-1) T
s+ (ζ
m+ η
m) T
s)=(x
m 2(1) ζ
m+ x
m 2(2)+x
m 2(3)+...+x
m 2(N
m))/(N
m-1+ ζ
m+ η
m),
(m=2,3,4 ...) (4) ζ wherein
m=x
m(1)/(x
m(1)+| x
M-1(N
M-1) |) (5) η
m=| x
m(N
m) |/(x
M+1(1)+| x
m(N
m) |) (6) and N
M-1It is the sampling number of m-1 cycle.
About ζ
m, η
mThe source can be explained as follows.Character according to tg (x) or sin (x) when x=0, has
tg(x)＝x???????????????????????????(7)
Sin (x)=x (8) departs from zero point as x, and (7) (8) two formulas are no longer strict to be set up, and calculating shows that at this moment the deviation of Chan Shenging is relevant with the size of x.Concrete deviation is: as x during respectively less than 0.2rad, 0.1rad, 0.05rad, the relative error of x and sin (x) or tg (x) is respectively less than 0.7%, 0.2%, 0.05%.Therefore (7) (8) two formulas are still set up in the error allowed band, so sinusoidal curve can be regarded straight line as.M cycle by the negative positive zero crossing place that becomes, replace sinusoidal curve with straight line after, we have ζ
m/ η
M-1=x
m(1)/| x
M-1(N
M-1) |, again because ζ
m+ η
M-1=1 simultaneous solution gets ζ
m=x
m(1)/(x
m(1)+| x
M-1(N
M-1) |) (9) η
M-1=| x
M-1(N
M-1) |/(x
m(1)+| x
M-1(N
M-1) |) (10) in like manner, become positive zero crossing at the next one by negative, promptly m+1 cycle by the positive zero crossing of negative change place, ζ is arranged
M-1=x
M+1(1)/(x
M+1(1)+| x
m(N
m) |) (11) η
m=| x
m(N
m) |/(x
M+1(1)+| x
m(N
m) |) sampling number of each cycle may difference, i.e. N here in (12) attention
M-1Need not be equal to N
m
From (4) (5) (6) formula as seen, the effective value of current cycle (m cycle) and last sampled value x of a last cycle (m-1 cycle)
M-1(N
M-1) relevant.First sampled value x after now measuring system being started
1(1) residing cycle called after the 1st cycle (being m=1).Do not work as yet because of measuring system when a last cycle (the 0th cycle), can't obtain the desired x of (5) formula
0(N
0) value and result of calculation ζ
1Value is so the effective value of the 1st cycle can't obtain.Therefore the measurement of effective value must be since the 2nd cycle (being m=2), and the continuous coverage of cycle is gone down one by one then.The reason that the m scope that formula that Here it is (4) provides begins from m=2.
1 is computing module among the figure, and 2 is A/D converter, and 3 is anti aliasing low pass or bandpass filter.Comprise microprocessor, program storage and data-carrier store in the computing module 1, the real effective calculation procedure that will use when program storage is deposited work, sampling routine and A/D converter 2 control programs.Data-carrier store contains array storage unit down: A unit: last data of depositing a cycle; B unit: the last sampled data of depositing current cycle; C unit: the current sampled data of depositing current cycle; D unit: the sampling number of depositing current cycle; E unit: deposit accumulated value; ζ unit: deposit (5) formula result of calculation; η unit: deposit (6) formula result of calculation.
Measuring process is described in detail as follows:
1, measuring system starts, cycle called after the 1st cycle that this moment is corresponding.
2, tested AC signal enters A/D converter 2 behind anti aliasing low pass or bandpass filter 3 elimination high frequency clutters, and the type of anti aliasing low pass or bandpass filter 3 and parameter are decided according to the operation instruction and the concrete measuring task of A/D converter.
3, computing module startup A/D converter is sampled to the 1st cycle, and the sampled value that obtains for the first time is x
1(1), with x
1(1) depositing the B unit in (is B=x
1(1)).
4, computing module is by constant sampling period T
sStart A/D converter, continue the sampling of the 1st cycle is obtained sampled value x
1(2).
5, computing module is with x
1(2) depositing the C unit in (is C=x
1(2)), judge x
1(2) whether be positive signal or zero-signal, if not, B=x then
1(2), arrive step 6 afterwards; If then further judge the x in the B unit
1(1) whether be negative signal, if not, B=x then
1(2), to step 6, if then explanation to the end of the 1st cycle, enters step 7 this moment.
6, repeating step 4 and step 5 continue tested AC signal sampling is obtained sampled value x successively
1(3), x
1(4), x
1(5) ..., to each sampled value deterministic process of repeating step 5 all.
7, according to the judged result of step 5, the sampled value of this moment has been first sampled value of next cycle (the 2nd cycle), and promptly the data that obtain this moment have been x in fact
2(1), and the sampled value of the last time of depositing in the B unit is actually last sampled value of the 1st cycle, i.e. x
1(N
1).
8, with x
1(N
1) to deposit the A unit in (be A=x
1(N
1)), B=x
2(1), numeral 1 deposits D unit (being D=1) in.Value x according to the A unit
1(N
1), the value x of B unit
2(1) and (5) formula calculate ζ
2, and with ζ
2Depositing the ζ unit in (is ζ=ζ
2).With x
2(1) the value ζ of squared back and ζ unit
2Multiply each other, with product x
2 2(1) ζ
2Depositing the E unit in (is E=x
2 2(1) ζ
2).
9, at this moment entered the 2nd cycle.The data that each memory cell is put are as follows, A unit: x
1(N
1), B unit: x
2(1), C unit: x
2(1), the D unit: 1, E unit: x
2 2(1) ζ
2
10, computing module continues by constant sampling period T
sStart A/D converter,, get sampled data x the sampling of the 2nd cycle
2(2).
11, C=x
2(2), computing module is judged x
2(2) whether be positive signal or zero-signal, if not, then with x
2(2) in squared back and the E unit original several additions to deposit the E unit more again in (be E=(E)+x
2 2(2)), the number in the D unit is added 1 (being D=(D)+1), B=x
2(2), arrive step 12 afterwards; If then further judge the x in the B unit
2(1) whether be negative signal, if not, E=(E)+x then
2 2(2), D=(D)+1, B=x
2(2), arrive step 12 afterwards, if then explanation to the end of the 2nd cycle, enters step 14 this moment.
12, continue the sampling deterministic process of repeating step 10 and step 11, that is, computing module continues by constant sampling period T
sStart A/D converter,, get subsequent sampling data x successively tested AC signal sampling
2(3), x
2(4) ..., whenever adopt data, all want the decision operation of execution in step 13.Now suppose just to obtain data x through sampling
2(k), will enter step 13 below.The data that this moment, each memory cell was put are as follows, A unit: x
1(N
1), B unit: x
2(k-1), C unit: x
2(k-1), D unit: k-1, E unit: x
2 2(1) ζ
2+x
2 2(2)+x
2 2(3)+…+x
2 2(k-1)。
13, C=x
2(k), computing module is judged x
2(k) whether be positive signal or zero-signal, if not, E=(E)+x then
2 2(k), D=(D)+1, B=x
2(k), arrive step 12 afterwards; If then further judge the x in the B unit
2(k-1) whether be negative signal, if not, E=(E)+x then
2 2(k), D=(D)+1, B=x
2(k), get back to step 12 afterwards, if then explanation to the end of the 2nd cycle, enters step 14 this moment.
14, according to the judged result of step 13, the sampled value of this moment has been first sampled value of next cycle (the 3rd cycle), and promptly the data that obtain this moment have been x in fact
3(1), and the sampled value of the last time of depositing in the B unit is actually last sampled value of the 2nd cycle, i.e. x
2(N
2), so according to (6) formula, by x
3(1) and x
2(N
2) calculate η
2, and with η
2Depositing the η unit in (is η=η
2), then according to the value x of E unit
2 2(1) ζ
2+ x
2 2(2)+x
2 2(3)+... + x
2 2(N
2), the value η of η unit
2, the ζ unit value ζ
2, the D unit value N
2And (4) formula is obtained the real effective of the 2nd cycle.
15, A=x
2(N
2), B=x
3(1), D=1 is according to the value x of A unit
2(N
2), the value x of B unit
3(1) and (5) formula calculate ζ
3, ζ=ζ
3, E=x
3 2(1) ζ
3
16, at this moment entered the 3rd cycle.The data that each memory cell is put are as follows, A unit: x
2(N
2), B unit: x
3(1), C unit: x
3(1), the D unit: 1, E unit: x
3 2(1) ζ
3
17, repeating step 10 to step 16 successively to the 3rd cycle, the 4th cycle, the 5th cycle ... Deng the calculating of sampling one by one, just can obtain the real effective of each cycle continuously.
The measuring relative errors of this method is relevant, also relevant with size, the frequency of harmonic wave in the tested AC signal with the sampling number N in the cycle.Calculating shows that when the sampling number N in the cycle was 8,16,32,64,128, corresponding measuring relative errors was respectively 0.92%, 0.12%, 0.02%, 0.002%, 0.0003%.Can prove that N is big more, measuring relative errors is just more little.For electric system, N=128 is enough to satisfy the accuracy requirement that most occasions are measured effective value, and N=128 is a condition that satisfies easily.On the other hand, strict calculating also shows to have relation as shown in the table (establishing N=128 here) between ratio R, the overtone order h of humorous wave amplitude and fundamental voltage amplitude and the measuring relative errors:
Ratio R, the overtone order h of humorous wave amplitude of table 1 and fundamental voltage amplitude and the relation between the measuring relative errors
As seen from Table 1, in indicating scope, the measuring error of this method is all very little, and much smaller than the desired effective value measuring error of most occasions (being generally 0.1% to 0.01%), R that is indicated and the scope of h also meet the actual conditions of the most occasions of electric system.
| 9 subharmonic | ????≤0.1 | ????9 | ????0.001％ |
| 10 subharmonic | ????≤0.1 | ????10 | ????0.001％ |
| 11 subharmonic | ????≤0.1 | ????11 | ????0.001％ |
| 12 subharmonic | ????≤0.08 | ????12 | ????0.001％ |
| 13 subharmonic | ????≤0.1 | ????13 | ????0.001％ |
| 14 subharmonic | ????≤0.07 | ????14 | ????0.001％ |
| 15 subharmonic | ????≤0.09 | ????15 | ????0.001％ |
| 16 subharmonic | ????≤0.06 | ????16 | ????0.001％ |
| 17 subharmonic | ????≤0.08 | ????17 | ????0.001％ |
| 32 subharmonic | ????≤0.03 | ????32 | ????0.001％ |
Embodiment:
Design an electric parameters transducer, so that actual alternating voltage is measured and its effective value is sent to host computer.Require the transmitter device volume little, can export the effective value of each cycle, measuring accuracy 0.2%.Current series is invented described method design transmitter.Computing module 1 is made up of chips such as 16 chip microprocessors, program storage, data-carrier store and auxiliary circuit, and A/D converter 2 is made up of 12 A/D chips and peripheral circuit.Sample frequency equals 6400Hz, and for the power frequency ac voltage of 50Hz, it is 156 microseconds that the sampling number of a cycle equals 128, two time intervals between the sampled point like this, is enough to allow chip microprocessor finish required calculation task.Anti aliasing low-pass filter 3 equals 2000Hz by cutoff frequency and designs.The whole device of computing module 1 control makes it work by formula (4)-(6) given mode.Actual measurement shows that the device of design meets the demands.Here, the in fact main error of error in measure, and the quantization error of A/D converter 2 generations from used components and parts.
Be applicable to that hardware system of the present invention has a lot, has just enumerated a kind of simple structure above.
Claims (1)
1, a kind of ac electric real effective digital measuring method is provided with array storage unit down at data-carrier store: A unit: last data of depositing a last cycle; B unit: the last sampled data of depositing current cycle; C unit: the current sampled data of depositing current cycle; D unit: the sampling number of depositing current cycle; E unit: deposit accumulated value; ζ unit: deposit (5) formula result of calculation; η unit: deposit (6) formula result of calculation; With the high frequency clutter elimination in the tested AC signal, send into A/D converter; Its measuring process is: (1), startup A/D converter are sampled to the 1st cycle, and the sampled value that obtains for the first time is x
1(1), makes B=x
1(1); (2), by constant sampling period T
sStart A/D converter, continue the sampling of the 1st cycle is obtained sampled value x
1(2); (3), make C=x
1(2), judge x
1(2) whether be positive signal or zero-signal, if not, make B=x
1(2), enter step 4.; If then further judge x
1(1) whether be negative signal, if not, B=x then
1(2), enter step 4., if enter step 5.; (4), repeating step 2. with step 3., continue tested AC signal sampling is obtained sampled value x successively
1(3), x
1(4), x
1(5), (5), make A=x
1(N
1), B=x
2(1), D=1 utilizes formula (5) formula to calculate ζ
2, make ζ=ζ
2, E=x
2 2(1) ζ
2, establish j=2; (6), enter j cycle, A=x at this moment
J-1(N
J-1), B=x
j(1), C=x
j(1), D=1, E=x
j 2(1) ζ
j, (7), continuation are by constant sampling period T
sStart A/D converter,, get sampled data x the sampling of j cycle
j(2); (8), make C=x
j(2), computing module is judged x
j(2) whether be positive signal or zero-signal, if not, make E=(E)+x
j 2(2), D=(D)+1, B=x
j(2), arrive step (9) afterwards; If then further judge the x in the B unit
j(1) whether is negative signal, if not, then makes E=(E)+x
j 2(2), D=(D)+1, B=x
j(2), arrive step (9) afterwards, if enter step (10); (9), repeating step (7) and step (8), successively subsequent sampling data x
j(3), x
j(4) ..., whenever adopt a data x
j(k), k=3,4 ..., make C=x
jAnd judge x (k),
j(k) whether be positive signal or zero-signal, if not, E=(E)+x then
j 2(k), D=(D)+1, B=x
j(k), arrive step afterwards 8.; If then further judge the x in the B unit
j(k-1) whether be negative signal, if not, then make E=(E)+x
j 2(k), D=(D)+1, B=x
j(k), get back to step (9) afterwards, if enter step (10); (10) Ci Shi sampled value is x
J+1And B=x (1),
j(N
j), calculate η according to (6) formula
j, and make η=η
j, obtain the real effective of j cycle according to (4) formula again; (11), make A=x
j(N
j), B=x
J+1(1), D=1 calculates ζ according to (5) formula
J+1, make ζ=ζ
3j+1, E=x
J+1 2(1) ζ
J+1(12), make j=j+1, repeating step (7) is to step (11), successively to the calculating of sampling of the cycle of postorder, until the real effective that obtains required each cycle; X wherein
Eff=(x
m 2(1) ζ
m+ x
m 2(2)+x
m 2(3)+...+x
m 2(N
m))/(N
m-1+ ζ
m+ η
m),
(m＝2，3，4，…)?????????????????????(4)ζ
m＝x
m(1)/(x
m(1)+|x
m-1(N
m-1)|)????????????????????????????(5)η
m＝|x
m(N
m)|/(x
m+1(1)+|x
m(N
m)|)?????????????????????????(6)。
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100454026C (en) * | 2005-07-28 | 2009-01-21 | 泰州苏源集团科电有限公司 | Cycle sampling method in quality of power supply in electrical network |
| CN102539892A (en) * | 2012-01-16 | 2012-07-04 | 南京磐能电力科技股份有限公司 | Method for obtaining true effective values of AC (alternating current) signals |
| CN104502673A (en) * | 2014-11-13 | 2015-04-08 | 浙江涵普电力科技有限公司 | AC-DC general current true RMS transmitter |
| CN104833844A (en) * | 2015-05-11 | 2015-08-12 | 上海市计量测试技术研究院 | Alternating-current effective value sampling measurement method |
| CN105353197A (en) * | 2015-07-17 | 2016-02-24 | 深圳市科润宝实业有限公司 | Method and device of measurement of alternating current True Root Mean Square (TRMS) |
| CN105954579A (en) * | 2016-04-29 | 2016-09-21 | 广州市隆星电子科技有限公司 | Alternating-current electric quantity rapid measurement and system protection method |
| CN111198293A (en) * | 2020-01-10 | 2020-05-26 | 北京航天测控技术有限公司 | Method for measuring effective value of alternating current signal |
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2003
- 2003-06-13 CN CN 03128151 patent/CN1208625C/en not_active Expired - Fee Related
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100454026C (en) * | 2005-07-28 | 2009-01-21 | 泰州苏源集团科电有限公司 | Cycle sampling method in quality of power supply in electrical network |
| CN102539892A (en) * | 2012-01-16 | 2012-07-04 | 南京磐能电力科技股份有限公司 | Method for obtaining true effective values of AC (alternating current) signals |
| CN102539892B (en) * | 2012-01-16 | 2014-04-02 | 南京磐能电力科技股份有限公司 | Method for obtaining true effective values of AC (alternating current) signals |
| CN104502673A (en) * | 2014-11-13 | 2015-04-08 | 浙江涵普电力科技有限公司 | AC-DC general current true RMS transmitter |
| CN104502673B (en) * | 2014-11-13 | 2017-07-14 | 浙江涵普电力科技有限公司 | The current true virtual value transmitter of AC/DC universal |
| CN104833844A (en) * | 2015-05-11 | 2015-08-12 | 上海市计量测试技术研究院 | Alternating-current effective value sampling measurement method |
| CN104833844B (en) * | 2015-05-11 | 2017-09-05 | 上海市计量测试技术研究院 | A kind of method of sampled measurements AC value |
| CN105353197A (en) * | 2015-07-17 | 2016-02-24 | 深圳市科润宝实业有限公司 | Method and device of measurement of alternating current True Root Mean Square (TRMS) |
| CN105954579A (en) * | 2016-04-29 | 2016-09-21 | 广州市隆星电子科技有限公司 | Alternating-current electric quantity rapid measurement and system protection method |
| CN105954579B (en) * | 2016-04-29 | 2019-05-17 | 广州市隆星电子科技有限公司 | A kind of ac electric rapid survey and system protection method |
| CN111198293A (en) * | 2020-01-10 | 2020-05-26 | 北京航天测控技术有限公司 | Method for measuring effective value of alternating current signal |
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