CN105022012A - Flicker precision detection method for digital electric energy quality monitoring terminal and system thereof - Google Patents

Abstract

The invention provides a flicker precision detection method for a digital electric energy quality monitoring terminal and a system thereof. The method comprises the steps that standard signals meeting the IEC61850-9-2 requirement are transmitted to the digital electric energy quality monitoring terminal; sampling is performed on the standard signals by the digital electric energy quality monitoring terminal and an MMS message is outputted; minute data of a short-term flicker index are confirmed according to the MMS message; and a short-term flicker measured value of the digital electric energy quality monitoring terminal is confirmed according to the minute data of the short-term flicker index. The IEC standard, detection precision and dynamic flicker detection capacity of the digital electric energy quality monitoring terminal can be identified, and flicker test capability of the electric energy quality terminal used for a digital transformer substation can be conveniently and rapidly assessed.

Description

The flickering accuracy checking method of digital electric power quality monitoring terminal and system

Technical field

The present invention is about the detection technique of the monitoring equipment in safe operation of power system, particularly about the detection technique of the transforming plant energy quality monitoring terminal in safe operation of power system, be a kind of flickering accuracy checking method and system of digital electric power quality monitoring terminal concretely.

Background technology

In recent years, the demand of the digital number formula electric energy quality monitoring terminal of whole nation each province grows with each passing day, but differ due to the level of the manufacturer of digital number formula electric energy quality monitoring terminal, flicker detection algorithm may be there is not according to GB or the problem such as measuring accuracy is inadequate in the digital number formula electric energy quality monitoring terminal of production.

Substantially be completed one by one by manual in laboratory to the detection of the flickering precision of digitizing digital electric power quality monitoring terminal in prior art, and the manual inspection in laboratory can only be spot-check or transfer passage numerical value wherein with computing machine, comprehensively can not check the indices of packet, also can have influence on the true reflection that electric network terminal detects data simultaneously.

At present, domestic also not about the flickering accuracy detection scheme of digital number formula electric energy quality monitoring terminal, IEC flickering standard simply show basic flicker test process flow diagram and general framework, does not provide concrete detection method.

Therefore, how the flickering precision of digital electric energy quality monitoring terminal is detected, promote detection efficiency, ensure the reliability of testing result, improve consistance and accuracy that device tests under complicated quality of power supply environment at the scene, to realize many inspections, fast inspection, excellent inspection be this area technical barrier urgently to be resolved hurrily.

Summary of the invention

In order to solve the technical matters that truly can not reflect electric network terminal detection data that the manual flickering precision detecting digital electric power quality monitoring terminal one by one in prior art causes, the invention provides a kind of flickering accuracy checking method and system of digital electric power quality monitoring terminal, digital electric power quality monitoring terminal can be screened out whether according to IEC standard, accuracy of detection and dynamic flicker detection ability, can assess the flicker test ability of digitizing transforming plant energy quality end easily and quickly.

An object of the present invention is, provides a kind of flickering accuracy checking method of digital electric power quality monitoring terminal, comprising: send to digital electric power quality monitoring terminal and meet IEC61850-9-2 required standard signal; Described digital electric power quality monitoring terminal is sampled to described standard signal, and exports MMS message; According to the minute data of described MMS message determination Short Term Flicker index; The Short Term Flicker measured value of described digital electric power quality monitoring terminal is determined according to the minute data of described Short Term Flicker index.

An object of the present invention is, provide a kind of flickering precision detection system of digital electric power quality monitoring terminal, described system specifically comprises: standard signal dispensing device, meets IEC61850-9-2 required standard signal for sending to digital electric power quality monitoring terminal; Described digital electric power quality monitoring terminal, for sampling to described standard signal, and exports MMS message; Minute data determining device, for the minute data according to described MMS message determination Short Term Flicker index; Short Term Flicker measured value determining device, for determining the Short Term Flicker measured value of described digital electric power quality monitoring terminal according to the minute data of described Short Term Flicker index.

Beneficial effect of the present invention is, provide a kind of flickering accuracy checking method and system of digital electric power quality monitoring terminal, not only solve the technical matters affecting the true reflection of electric network terminal detection data that the manual flickering precision detecting digital electric power quality monitoring terminal one by one in prior art causes, and digital electric power quality monitoring terminal can be screened out whether according to IEC standard, accuracy of detection and dynamic flicker detection ability, can assess the flicker test ability of digitizing transforming plant energy quality end easily and quickly.

For above and other object of the present invention, feature and advantage can be become apparent, preferred embodiment cited below particularly, and coordinate institute's accompanying drawings, be described in detail below.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

The process flow diagram of the embodiment one of the flickering accuracy checking method of a kind of digital electric power quality monitoring terminal that Fig. 1 provides for the embodiment of the present invention;

The process flow diagram of the embodiment two of the flickering accuracy checking method of a kind of digital electric power quality monitoring terminal that Fig. 2 provides for the embodiment of the present invention;

Fig. 3 is the particular flow sheet of the step S203 in Fig. 2;

Fig. 4 is the particular flow sheet of the step S204 in Fig. 2;

The structured flowchart of the embodiment one of the flickering precision detection system of a kind of digital electric power quality monitoring terminal that Fig. 5 provides for the embodiment of the present invention;

The structured flowchart of the embodiment two of the flickering precision detection system of a kind of digital electric power quality monitoring terminal that Fig. 6 provides for the embodiment of the present invention;

The structured flowchart of minute data determining device 300 in the flickering precision detection system of a kind of digital electric power quality monitoring terminal that Fig. 7 provides for the embodiment of the present invention;

The structured flowchart of flicker measurement value determining device 400 in short-term in the flickering precision detection system of a kind of digital electric power quality monitoring terminal that Fig. 8 provides for the embodiment of the present invention;

Fig. 9 is the overhaul flow chart of flicker detection standard IEC 61000-4-15;

When Figure 10 is non-complete matching there is the schematic diagram of interference in adjacent signals;

When Figure 11 is non-complete matching there is not the schematic diagram of interference in adjacent signals;

Figure 12 is the schematic diagram that standard signal exports;

Figure 13 is standard signal instantaneous vermicularizing alloy Distribution value figure (10min);

Figure 14 is standard signal effective value distribution plan (10min).

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

The object of this invention is to provide a kind of flickering accuracy checking method of the digital transformer substation electric energy quality monitoring terminal successively decreased step by step based on the undulate quantity of IEC flickering standard, the dynamic flicker detection ability of digital transformer substation electric energy quality monitoring terminal can be screened out.

First the testing process of flicker detection standard IEC 61000-4-15 is introduced below.Flicker detection standard IEC 61000-4-15 is the modulated wave flickering model based on incandescent lamp & lantern, and its flicker detection flow process as shown in Figure 9.IEC flickering signal general expression based on multiple modulated wave flickering model is:

$u_{\mathrm{AM}}\left(t\right)=A[1+\underset{f}{\mathrm{\Σ}}{m}_f\cos ({\mathrm{\Ω}}_{f}t+{\mathrm{\θ}}_f)]\cos \mathrm{\ωt}$

Wherein, A, ω represent amplitude, the angular frequency of work frequency carrier voltage, m _f, Ω _fand θ _frepresent the amplitude coefficient of each modulated wave voltage, angular frequency and phase place.

Flickering signal exports after square demod-ulation device:

$\begin{array}{c}{u}_{\mathrm{AM}}^2\left(t\right)=\frac{A^2}{2}(1+\frac{1}{2}\underset{f}{\mathrm{\Σ}}{m}_f^2)+A^2\underset{f}{\mathrm{\Σ}}{m}_f\cos ({\mathrm{\Ω}}_{f}t+{\mathrm{\θ}}_f)+\\ A^2\underset{i\≠j}{\mathrm{\Σ}}{m}_{f_i}{m}_{f_i}\cos ({\mathrm{\Ω}}_{f_i}t+{\mathrm{\θ}}_{f_i})\cos ({\mathrm{\Ω}}_{f_j}t+{\mathrm{\θ}}_{f_j})+\\ =\frac{A^2}{4}\underset{f}{\mathrm{\Σ}}{m}_f^2\cos 2({\mathrm{\Ω}}_{f}t+{\mathrm{\θ}}_f)+R(2\mathrm{\ω},{\mathrm{\Ω}}_f)\end{array}$

Wherein, R (2 ω, Ω _f) represent all frequency components relevant to 2 times of power frequencies.

The output signal of square demod-ulation device after 0.05Hz ~ 35Hz bandpass filter, DC component A ²/ 2 and frequency component R (2 ωs, the Ω relevant to 2 times of power frequencies _f) will by filtering.Demodulate cause the modulated wave component of flickering export be:

$v_{3-1}\left(t\right)=A^2\underset{f}{\mathrm{\Σ}}{m}_f\cos ({\mathrm{\Ω}}_{f}t+{\mathrm{\θ}}_f)$

Signal v after 0.05 ~ 35Hz bandpass filter _3-1t () carries out 8.8Hz weighted filtering again.From 8.8Hz weighting filter signal be out:

$v_3\left(t\right)=A^2\underset{f}{\mathrm{\Σ}}{K}_f{R}_f{m}_f\cos ({\mathrm{\Ω}}_{f}t+{\mathrm{\θ}}_f)$

Wherein, K _f, R _ffor visual sense degree coefficient and the waveform factor of corresponding modulated wave frequency.8.8Hz weighting filter output signal v ₃t () is first multiplied by 1/A ²carry out amplitude normalized, then pass through squarer.The direct current signal of squarer extracts by single order smoothing filter.

Therefore, equivalent 8.8Hz sine modulation wave voltage undulating quantity square is:

$d_{8.8\mathrm{hz}}^2=\frac{{(\mathrm{\ΔU}/\sqrt{2})}^2}{{(1/\sqrt{2})}^2}=\underset{f}{\mathrm{\Σ}}{(K_f{R}_f\·2m_f)}^2$

According to IEC standard regulation, frequency is 8.8Hz and a unit flickering causing of the sine modulation ripple that magnitude of a voltage fluctuation is 0.25%, so instantaneous flicker P _insttheory calculate expression formula be:

$P_{\mathrm{inst}}=\frac{d_{8.8\mathrm{Hz}}^2}{{(0.25\%)}^2}=\underset{f}{\mathrm{\Σ}}{(4K_f{R}_f\·100d_f)}^{\text{2}}$

Above formula shows the square proportional of instantaneous flicker value and magnitude of a voltage fluctuation the gain coefficient K value that single order smoothing filter Output rusults is converted to needed for instantaneous flicker value is:

$K=\frac{P_{\mathrm{inst}}}{v_{B4}\left(t\right)}{\left(\frac{2\sqrt{2}}{0.25\%}\right)}^2=1.28\×{10}^6$

IEC standard specifies the statistical treatment to instantaneous flicker value:

1. in observation phase (10min), statistics instantaneous flicker value P _instresult of calculation, classification timing (being greater than 64 grades).

2. the T.T. of instantaneous flicker at different levels is added up respectively, with T _short(10min) percentage represents, calculating probability density function (PDF).

3. statistics is less than or equal to the T.T. of certain grade of instantaneous flicker value, with T _short(10min) percentage represents, calculates Cumulative Distribution Function (CDF).

4. P _0.1, P ₁, P ₃, P ₁₀, P ₅₀for cumulative probability more than 0.1%, 1%, 3%, 10%, the instantaneous flicker value of 50%.P _instt () arranges from small to large, choose the large value of 99.9%, 99%, 97%, 90%, 50% probability.P _instt () discrete series is constant duration, as being less than P _{inst, N}all P _{inst, i}the corresponding time accounts for the N% of whole observation phase, be then not less than P _{inst, N}all P _{inst, i}number also account for P in this time period _{inst, i}the N% of sum, i.e. P _{inst, N}for this period P _instthe large value of (100-N%) probability of sequence.

10min Short Term Flicker Severity (P _st):

$P_{\mathrm{st}}=\sqrt{0.0314P_{0.1}+0.0525P_{1s}+0.0657P_{3s}+0.28P_{10s}+0.08P_{50s}}$

Wherein, P _1s=(P _0.7+ P ₁+ P _1.5)/3, P _3s=(P _2.2+ P ₃+ P ₄)/3,

P _10s＝(P ₆+P ₈+P ₁₀+P ₁₃+P ₁₇)/5，P _50s＝(P ₃₀+P ₅₀+P ₈₀)/3。

More than be IEC61000-4-15 flicker detection flow process.

As shown in Figure 1, as shown in Figure 1, in embodiment one, described method comprises the particular flow sheet of the flickering accuracy checking method of a kind of digital electric power quality monitoring terminal that the present invention proposes:

S101: send to digital electric power quality monitoring terminal and meet IEC61850-9-2 required standard signal.

Standard signal designed by detection scheme of the present invention is considered for most domestic digital electric power quality monitoring terminal, sampling initial time is all sampled from whole minute, but because the signal of digital electric power quality monitoring terminal sampling time and standard source exports program control response time delay that is asynchronous and standard source self, can cause the sampling period can not complete matching with output signal, thus two signals are contained within a sampling period, and it is unavailable finally to cause the less signal of effective value to leak the data of adopting or adopting, as adjacent signals when Figure 10 is non-complete matching exists the schematic diagram of interference, when Figure 11 is non-complete matching there is not the schematic diagram of interference in adjacent signals.

For solving the problem, consider that digital electric power quality monitoring terminal adopts record segment (as 1 minute) maximum, minimum, average to 3 records by 3 seconds square averages, adopt a kind of record segment maximal value filtration method to extract the detection signal wanted, its mathematical expression is

$\left[\begin{array}{ccc}{x}_{1\max }& x_{1\min }& x_{\mathrm{av}}\\ \·& \·& \·\\ \·& \·& \·\\ \·& \·& \·\\ x_{k\max }& x_{k\min }& x_{\mathrm{kav}}\\ \·& \·& \·\\ \·& \·& \·\\ \·& \·& \·\\ x_{n\max }& x_{n\min }& x_{\mathrm{nav}}\end{array}\right]\·\left[\begin{array}{c}1\\ 0\\ 0\end{array}\right]=\left[\begin{array}{c}{x}_{1\max }\\ \·\\ \·\\ \·\\ x_{k\min }\\ \·\\ \·\\ \·\\ x_{\mathrm{nav}}\end{array}\right]$

In above formula, x _1maxx _kmaxx _nmaxn 3 seconds r.m.s. maximal value in representative digit formula electric energy quality monitoring terminal one minutes section, x _1minx _kminx _nminn 3 seconds r.m.s. minimum value in representative digit formula electric energy quality monitoring terminal one minute section, x _avx _kavx _navn 3 seconds root-mean-square average value in representative digit formula electric energy quality monitoring terminal one minute section.

As long as arrange always to appear at the maximum of record segment for the signal detected, the detection sequence constructed thus just can realize the automatic detection of continuous signal.Therefore, the time span of the flickering precision signal of the digital transformer substation electric energy quality monitoring terminal successively decreased step by step based on flickering undulate quantity that detection scheme of the present invention proposes is 20 minutes.Like this, the flicker detection experiment of many groups can be done, not interfere with each other between each group signal.And no matter when monitoring terminal starts sampling, all can be complete collect 10 minutes flickering signals.

Standard signal of the present invention is: the fluctuation size of front 3.5% time period is 0.25%, the sine modulation ripple of 8.8HZ; The undulate quantity of time period of following 7.5% is the sine modulation ripple of 8.8HZ; The undulate quantity of ensuing 60% time period is sine modulation ripple is 9.5HZ; The undulate quantity of last 29% time period is sine modulation wave frequency is 8.8HZ, totally four time periods, 10 minutes, within ensuing 10 minutes, repeats four time periods above again, and the length of standard signal is 20 minutes.

Owing to being detect digital electric power quality monitoring terminal, therefore the form of standard signal should meet IEC61850-9-2 requirement, in a particular embodiment, the relay-protection tester of DRT-802 model can be utilized to realize format conversion.

Figure 12 is the schematic diagram that standard signal exports, and as shown in Figure 12, first, user data, by the exchanges data mouth of DRT-802, enters relay-protection tester inside.According to the routine data model of the user preset, the model analyzing CMOS macro cell conventional model data-interface of DRT-802 inside, the routine data of user is converted to the third data layout that instrument can receive by this interface.Then, data mart modeling is become the data layout meeting IEC61850-9-2 by the third data layout through mapping ruler.Finally, the data set model required according to user, will meet the data layout arrangement of IEC61850-9-2, export the standard signal of IEC61850-9-2.

S102: described digital electric power quality monitoring terminal is sampled to described standard signal, and export MMS (industrial manufacturing standard message) message.Standard signal arrives digital electric power quality monitoring terminal, and after 20 minutes, digital electric power quality monitoring terminal is added up standard after having sampled, and exports after result is put into MMS message.

S103: according to the minute data of described MMS message determination Short Term Flicker index.

S104: the Short Term Flicker measured value determining described digital electric power quality monitoring terminal according to the minute data of described Short Term Flicker index.

The process flow diagram of the embodiment two of the flickering accuracy checking method of a kind of digital electric power quality monitoring terminal that Fig. 2 provides for the embodiment of the present invention, as shown in Figure 2, in embodiment two, the method specifically comprises:

S201: send to digital electric power quality monitoring terminal and meet International Electrotechnical Commission IEC61850-9-2 required standard signal.Standard signal of the present invention is: the fluctuation size of front 3.5% time period is 0.25%, the sine modulation ripple of 8.8HZ; The undulate quantity of time period of following 7.5% is the sine modulation ripple of 8.8HZ; The undulate quantity of ensuing 60% time period is sine modulation ripple is 9.5HZ; The undulate quantity of last 29% time period is sine modulation wave frequency is 8.8HZ, totally four time periods, 10 minutes, within ensuing 10 minutes, repeats four time periods above again, and the length of standard signal is 20 minutes.

S202: described digital electric power quality monitoring terminal is sampled to described standard signal, and exports MMS message.Standard signal arrives digital electric power quality monitoring terminal, and after 20 minutes, digital electric power quality monitoring terminal is added up standard after having sampled, and exports after result is put into MMS message.

S203: according to the minute data of described MMS message determination Short Term Flicker index.Fig. 3 is the particular flow sheet of step S203, and as shown in Figure 3, this step specifically comprises:

S301: the MMS message described in parsing;

S302: the minute data extracting Short Term Flicker index in the MMS message analytically.

As shown in Figure 2, in embodiment two, the method also comprises:

S204: the Short Term Flicker measured value determining described digital electric power quality monitoring terminal according to the minute data of described Short Term Flicker index.Fig. 4 is the particular flow sheet of step S204, and as shown in Figure 4, this step specifically comprises:

S401: to extract in Short Term Flicker theoretical value first non-vanishing value from the minute data of described Short Term Flicker index;

S402: determine the moment that described first non-vanishing value is corresponding to be called for the first moment;

S403: the first described moment is added 10 minutes and obtained for the second moment;

S404: determine the Short Term Flicker measured value that described second moment is corresponding.The Short Term Flicker value that Short Term Flicker theory index inside the MMS message that parsing measured number formula electric energy quality monitoring terminal returns comprises, in the second moment described in utilization, finds corresponding Short Term Flicker measured value.

By IEC61850 client, MMS packet parsing is gone out to the measured value of various index, such as, the indexs such as the frequency returned, tri-phase unbalance factor, voltage, Short Term Flicker.The flickering standard signal that the present invention proposes, finds the measured value under Short Term Flicker index catalogue, and does not need to look for these catalogues of frequency, three-phase imbalance in the message that just should analytically go out.Measured value is not single, because it is made up of the minute data of continuous time, just has the measured value of a flickering every one minute, and monitoring terminal will form a tables of data measured through sampling after a while.Find the measured value of standard signal in this table the inside, determine the first moment and the second moment.Determine the Short Term Flicker measured value that described second moment is corresponding, as long as have found for the second moment, just can find in meter under the catalogue of the Short Term Flicker index of monitoring terminal and the second moment Short Term Flicker measured value one to one, and this value is thought the Short Term Flicker measured value of electric energy quality monitoring terminal to standard signal.The Short Term Flicker measured value of digital electric power quality monitoring terminal and actual P _stNvalue.

As shown in Figure 2, in embodiment two, the method also comprises:

S205: the Short Term Flicker theoretical value obtaining described standard signal.Short Term Flicker theoretical value and standard P st value.

Obtain the theoretical value of described standard detection signature.According to the theory that the present invention introduces, the statistical formula provided according to IEC standard calculates, the Short Term Flicker theoretical value (smoothing processing) of this detection signal:

$\begin{array}{c}{p}_{\mathrm{st}}=\sqrt{0.0314p_{0.1s}+0.0525p_{1s}+0.0657p_{3s}+0.28p_{10s}+0.08p_{50s}}\\ =\sqrt{0.0314\×1+0.0525\×1+0.0657\×0.75+0.28\×0.19444+0.08\×0.094901}\\ =0.4418\end{array}$

Wherein, p _0.1s=1, p _1s=(p _0.7+ p ₁+ p _1.5)/3=p _0.7=p ₁=p _1.5=1

$p_{3s}=(p_{2.2}+p_3+p_4)/3=(1+1+\frac{1}{4})/3=0.75$

$p_{10s}=(p_6+p_8+p_{10}+p_{13}+p_{17})/5=(\frac{1}{4}+\frac{1}{4}+\frac{1}{4}+\frac{1}{9}+\frac{1}{9})/5=0.1944444$

$p_{50s}=(p_{30}+p_{50}+p_{80})/3=(\frac{1}{9}+\frac{1}{9}+\frac{1}{16})=0.0949074$

S206: described Short Term Flicker theoretical value and described Short Term Flicker measured value are compared, obtains comparison result.S207: whether the digital electric power quality monitoring terminal described in judging according to described comparison result meets IEC standard.

According to the actual P that the precision of the flickering Pst value specified in " electric energy quality on-line monitoring device technical manual " (QGDW-10-J393-2009) is digital electric power quality monitoring terminal record _stNthe difference of value and standard P st value is to the number percent of standard P st value, and accuracy computation formula is the precision of flickering Pst value is 5%, and the precision of standard source flickering is q%, and revised error range is $P_{{\mathrm{st}}_N}*(1-q\%)*(1-5\%)\≤P_{\mathrm{st}}\≤P_{{\mathrm{st}}_N}*(1+q\%)*(1+5\%).$ The precision of standard source flickering is 5/100000ths, i.e. the actual P of digital electric power quality monitoring terminal record _stNthe difference of value and standard P st value between-5.00475% to+5.00525%, can think that the flickering monitoring accuracy of digital electric power quality monitoring terminal meets IEC standard to the number percent of standard P st value.As shown in figure 13, effective value distribution plan as shown in figure 14 for the instantaneous vermicularizing alloy Distribution value figure of flicker detection signal.

As above the flickering accuracy checking method of the digital transformer substation electric energy quality monitoring terminal successively decreased step by step based on flickering undulate quantity provided by the invention is, digital electric power quality monitoring terminal can be screened out whether according to IEC standard, accuracy of detection and dynamic flicker detection ability, only need the constantly undulate quantity of change and a detection signal for vibration frequency, just can assess the flicker test ability of digitizing transforming plant energy quality end easily and quickly.

The present invention also proposes a kind of flickering precision detection system of digital electric power quality monitoring terminal, and Fig. 5 is the structured flowchart of the embodiment one of this system, and as shown in Figure 5, in embodiment one, described system comprises:

Standard signal dispensing device 100, meets IEC61850-9-2 required standard signal for sending to digital electric power quality monitoring terminal.

Standard signal designed by detection scheme of the present invention is considered for most domestic digital electric power quality monitoring terminal, sampling initial time is all sampled from whole minute, but because the signal of digital electric power quality monitoring terminal sampling time and standard source exports program control response time delay that is asynchronous and standard source self, can cause the sampling period can not complete matching with output signal, thus two signals are contained within a sampling period, and it is unavailable finally to cause the less signal of effective value to leak the data of adopting or adopting, as adjacent signals when Figure 10 is non-complete matching exists the schematic diagram of interference, when Figure 11 is non-complete matching there is not the schematic diagram of interference in adjacent signals.

For solving the problem, consider that digital electric power quality monitoring terminal adopts record segment (as 1 minute) maximum, minimum, average to 3 records by 3 seconds square averages, adopt a kind of record segment maximal value filtration method to extract the detection signal wanted, its mathematical expression is

$\left[\begin{array}{ccc}{x}_{1\max }& x_{1\min }& x_{\mathrm{av}}\\ \·& \·& \·\\ \·& \·& \·\\ \·& \·& \·\\ x_{k\max }& x_{k\min }& x_{\mathrm{kav}}\\ \·& \·& \·\\ \·& \·& \·\\ \·& \·& \·\\ x_{n\max }& x_{n\min }& x_{\mathrm{nav}}\end{array}\right]\·\left[\begin{array}{c}1\\ 0\\ 0\end{array}\right]=\left[\begin{array}{c}{x}_{1\max }\\ \·\\ \·\\ \·\\ x_{k\min }\\ \·\\ \·\\ \·\\ x_{\mathrm{nav}}\end{array}\right]$

In above formula, x _1maxx _kmaxx _nmaxn 3 seconds r.m.s. maximal value in representative digit formula electric energy quality monitoring terminal one minutes section, x _1minx _kminx _nminn 3 seconds r.m.s. minimum value in representative digit formula electric energy quality monitoring terminal one minute section, x _avx _kavx _navn 3 seconds root-mean-square average value in representative digit formula electric energy quality monitoring terminal one minute section.

As long as arrange always to appear at the maximum of record segment for the signal detected, the detection sequence constructed thus just can realize the automatic detection of continuous signal.Therefore, the time span of the flickering precision signal of the digital transformer substation electric energy quality monitoring terminal successively decreased step by step based on flickering undulate quantity that detection scheme of the present invention proposes is 20 minutes.Like this, the flicker detection experiment of many groups can be done, not interfere with each other between each group signal.And no matter when monitoring terminal starts sampling, all can be complete collect 10 minutes flickering signals.

Standard signal of the present invention is: the fluctuation size of front 3.5% time period is 0.25%, the sine modulation ripple of 8.8HZ; The undulate quantity of time period of following 7.5% is the sine modulation ripple of 8.8HZ; The undulate quantity of ensuing 60% time period is sine modulation ripple is 9.5HZ; The undulate quantity of last 29% time period is sine modulation wave frequency is 8.8HZ, totally four time periods, 10 minutes, within ensuing 10 minutes, repeats four time periods above again, and the length of standard signal is 20 minutes.

Minute data determining device 200, samples to described standard signal for described digital electric power quality monitoring terminal, and exports MMS message.Standard signal arrives digital electric power quality monitoring terminal, and after 20 minutes, digital electric power quality monitoring terminal is added up standard after having sampled, and exports after result is put into MMS message.

Minute data determining device 300, for the minute data according to described MMS message determination Short Term Flicker index.Fig. 7 is the structured flowchart of minute data determining device 300, and as shown in Figure 7, minute data determining device 300 specifically comprises:

Parsing module 301, for resolving described MMS message;

Minute data extraction module 302, for extracting the minute data of Short Term Flicker index in the MMS message after analytically.

As shown in Figure 5, this system also comprises:

Short Term Flicker measured value determining device 400, for determining the Short Term Flicker measured value of described digital electric power quality monitoring terminal according to the minute data of described Short Term Flicker index.Fig. 8 is the structured flowchart of Short Term Flicker measured value determining device 400, and as shown in Figure 8, Short Term Flicker measured value determining device 400 specifically comprises:

Extraction module 401, for extracting in Short Term Flicker measured value first non-vanishing value in the minute data table from described Short Term Flicker index;

First moment determination module 402, for determining the moment that described first non-vanishing value is corresponding, was called for the first moment;

Second moment determination module 403, obtained for the second moment for the first described moment is added 10 minutes;

Short Term Flicker measured value determination module 404, for determining the Short Term Flicker measured value that described second moment is corresponding, the Short Term Flicker value that Short Term Flicker theory index inside the MMS message that parsing measured number formula electric energy quality monitoring terminal returns comprises, in the second moment described in utilization, find corresponding Short Term Flicker measured value.

By IEC61850 client, MMS packet parsing is gone out to the measured value of various index, such as, the indexs such as the frequency returned, tri-phase unbalance factor, voltage, Short Term Flicker.The flickering standard signal that the present invention proposes, finds the measured value under Short Term Flicker index catalogue, and does not need to look for these catalogues of frequency, three-phase imbalance in the message that just should analytically go out.Measured value is not single, because it is made up of the minute data of continuous time, just has the measured value of a flickering every one minute, and monitoring terminal will form a tables of data measured through sampling after a while.Find the measured value of standard signal in this table the inside, determine the first moment and the second moment.Determine the Short Term Flicker measured value that described second moment is corresponding, as long as have found for the second moment, just can find in meter under the catalogue of the Short Term Flicker index of monitoring terminal and the second moment Short Term Flicker measured value one to one, and this value is thought the Short Term Flicker measured value of electric energy quality monitoring terminal to standard signal.The Short Term Flicker measured value of digital electric power quality monitoring terminal and actual P _stNvalue.

The structured flowchart of the embodiment two of the flickering precision detection system of a kind of digital electric power quality monitoring terminal that Fig. 6 provides for the embodiment of the present invention, as shown in Figure 6, in embodiment two, this system specifically comprises:

Short Term Flicker theoretical value acquisition device 500, for obtaining the Short Term Flicker theoretical value of described standard signal, Short Term Flicker theoretical value and standard P st value.

Obtain the theoretical value of described standard detection signature.According to the theory that the present invention introduces, the statistical formula provided according to IEC standard calculates, the Short Term Flicker theoretical value (smoothing processing) of this detection signal:

$\begin{array}{c}{p}_{\mathrm{st}}=\sqrt{0.0314p_{0.1s}+0.0525p_{1s}+0.0657p_{3s}+0.28p_{10s}+0.08p_{50s}}\\ =\sqrt{0.0314\×1+0.0525\×1+0.0657\×0.75+0.28\×0.19444+0.08\×0.094901}\\ =0.4418\end{array}$

Wherein, p _0.1s=1, p _1s=(p _0.7+ p ₁+ p _1.5)/3=p _0.7=p ₁=p _1.5=1

$p_{3s}=(p_{2.2}+p_3+p_4)/3=(1+1+\frac{1}{4})/3=0.75$

$p_{10s}=(p_6+p_8+p_{10}+p_{13}+p_{17})/5=(\frac{1}{4}+\frac{1}{4}+\frac{1}{4}+\frac{1}{9}+\frac{1}{9})/5=0.1944444$

$p_{50s}=(p_{30}+p_{50}+p_{80})/3=(\frac{1}{9}+\frac{1}{9}+\frac{1}{16})=0.0949074$

Comparison device 600, for described Short Term Flicker theoretical value and described Short Term Flicker measured value being compared, obtains comparison result.

Whether judgment means 700, meet IEC standard for the digital electric power quality monitoring terminal described in judging according to described comparison result.

According to the actual P that the precision of the flickering Pst value specified in " electric energy quality on-line monitoring device technical manual " (QGDW-10-J393-2009) is digital electric power quality monitoring terminal record _stNthe difference of value and standard P st value is to the number percent of standard P st value, and accuracy computation formula is the precision of flickering Pst value is 5%, and the precision of standard source flickering is q%, and revised error range is $P_{{\mathrm{st}}_N}*(1-q\%)*(1-5\%)\≤P_{\mathrm{st}}\≤P_{{\mathrm{st}}_N}*(1+q\%)*(1+5\%).$ The precision of standard source flickering is 5/100000ths, i.e. the actual P of digital electric power quality monitoring terminal record _stNthe difference of value and standard P st value between-5.00475% to+5.00525%, can think that the flickering monitoring accuracy of digital electric power quality monitoring terminal meets IEC standard to the number percent of standard P st value.As shown in figure 13, effective value distribution plan as shown in figure 14 for the instantaneous vermicularizing alloy Distribution value figure of flicker detection signal.

As above the flickering precision detection system of a kind of digital electric power quality monitoring terminal provided by the invention is, digital electric power quality monitoring terminal can be screened out whether according to IEC standard, accuracy of detection and dynamic flicker detection ability, only need the constantly undulate quantity of change and a detection signal for vibration frequency, just can assess the flicker test ability of digitizing transforming plant energy quality end easily and quickly.

Below in conjunction with specific embodiment, introduce technical scheme of the present invention in detail.

The critical function of digital electric power quality monitoring terminal can identify exactly accurately, monitor stable state and dynamically flickering, but for some domestic monitoring terminal manufacturing firm, not according to the specification testing process in IEC61000-4-15, but adopt a kind of simple, approximate-mean value statistic law.Instantaneous flicker value P is obtained by filtering link _instafter (n), carry out classification according to IEC standard, but substitution formula obtains Short Term Flicker

So, the flicker detection signal of Technical Design of the present invention, with the measurement result of IEC method and mean value statistic law and relative error as shown in table 1:

Table 1

Can be found out by table 1:

1. mean value statistic law is only 0.32% at stable state flicker test medial error, meets Standard (A level maximum error ± 5%, B level maximum error ± 10%), almost equal with theoretical value.But, the flicker detection signal of Technical Design of the present invention, the dynamic flickering signal that undulate quantity amplitude is successively decreased step by step, because mean value statistic law is by all instantaneous flicker value equalizations, its result is reduced, and error reaches-39.86%;

2. the flicker detection signal of technical side's design of the present invention, can distinguish the whether smoothing process of sense terminals well, the theoretical value (smoothing processing) of A phase test signal is equal with theoretical value (non-smoothing processing).Because the flicker detection signal of the technical program design is respectively in the undulate quantity sudden change of 3.5%, 11%, 71% time period, disturb p ₄, p ₁₃, p ₁₇, p ₈₀value, the error that the theoretical value of non-smoothing processing is occurred is large.

The flicker detection signal of the technical program design, can also screen out and whether utilize virtual value method.So-called virtual value method is exactly by u ²t () deducts reference voltage A ²integration after/2, the component being greater than 2w at integration medium frequency can be ignored, the coefficient of the modulated wave detected its coefficient is no longer constant, but relevant with vibration frequency.The modulated wave detected due to virtual value method also will make the flickering value calculated decay with the increase of vibration frequency with the characteristic that wave characteristic is decayed, therefore, the flicker detection signal that present design proposes, within the time period of 11%---71%, allow vibration frequency raise, change p ₃₀, p ₅₀, last Short Term Flicker theoretical value reduces.

In order to verify the accuracy of technical solution of the present invention further, adopting simulink to build the flickermeter model of IEC61000-4-15 recommendation, and obtaining the error of realistic model, as shown in table 2.

Table 2

As can be seen from Table 2, the flickermeter model that IEC recommends can reasonablely detect and dynamically flickering, occurs that the reason of error may be that the cutoff frequency design of some wave filters in IEC model is improper, makes the state that wave filter does not reach desirable; From the simulation result of effective value, the modulated wave detected due to virtual value method also will make the flickering value calculated decay with the increase of vibration frequency with the characteristic that wave characteristic is decayed, therefore, the flicker detection signal that the present invention program proposes, within the time period of 11%---71%, allow vibration frequency raise, change p ₃₀, p ₅₀, last Short Term Flicker theoretical value reduces, and demonstrates the flicker detection signal correctness of the technical program design.

In order to make the technical program more have extendability, provide the theoretical value of several groups of typical flicker detection signals below, table 3 is the typical five groups of detection signals of technical solution of the present invention:

Table 3

Next, the PQS-883 digital transformer substation electric energy quality monitoring terminal of Nanjing Shining Electric Power Automation Co., Ltd. is selected to test, flicker detection signal setting is as unanimously above-mentioned, and Nanjing bright energy PQS-883 electric energy quality monitoring terminal experimental result is as shown in table 4 below:

Table 4

Time	A phase Short Term Flicker value	B phase Short Term Flicker value	C phase Short Term Flicker value
				2013.12.3115:14:00	0.0000	0.0000	0.0000
2013.12.3115:15:00	0.2138	0.2211	0.1941
				2013.12.3115:16:00	0.4327	0.4331	0.4322
2013.12.3115:17:00	0.4327	0.4331	0.4322
				2013.12.3115:18:00	0.4327	0.4331	0.4322
2013.12.3115:19:00	0.4327	0.4331	0.4322
				2013.12.3115:20:00	0.4327	0.4331	0.4322
2013.12.3115:21:00	0.4327	0.4331	0.4322
				2013.12.3115:22:00	0.4327	0.4331	0.4322
2013.12.3115:2300	0.4327	0.4331	0.4322
				2013.12.3115:24:00	0.4327	0.4331	0.4322
2013.12.3115:25:00	0.4327	0.4331	0.4322
				2013.12.3115:26:00	0.4327	0.4331	0.4322
2013.12.3115:27:00	0.3565	0.2277	0.2265
				2013.12.3115:28:00	0.0000	0.0000	0.0000

It should be noted that, as shown in table 4, experimental result adopts the collection minute data of monitoring terminal, in 15:15 timesharing, the Short Term Flicker value of A phase is 0.5138, mainly because the time of flicker detection signal monitored terminal sampling is not whole minute, in addition, in actual measurement, first monitoring terminal will sample the flickering signal of a complete 10min, and connect the lower inner statistical value that just can provide Short Term Flicker, therefore 15: 15 detection signals have proceeded to the 11 minute, in ensuing 10min, per minute have Short Term Flicker value.From experimental result, the Short Term Flicker value precision of A, B, C phase flickering signal reaches 2%, illustrate that the stable state flicker test precision of Nanjing bright energy PQS-883 device meets the requirement of A level equipment, demonstrating this device is the correctness meeting IEC61000-4-15 standard and this detection signal.

Through experiment, adopt matlab analogue simulation, and use it for the detection of multiple power quality analyzer, the feasibility of result sufficient proof technical solution of the present invention.

In sum, the invention provides a kind of flickering accuracy checking method and system of digital electric power quality monitoring terminal, not only solve the technical matters affecting the true reflection of electric network terminal detection data that the manual flickering precision detecting digital electric power quality monitoring terminal one by one in prior art causes, and digital electric power quality monitoring terminal can be screened out whether according to IEC standard, accuracy of detection and dynamically flicker detection ability, only need the constantly undulate quantity of change and a detection signal for vibration frequency, just can facilitate, rapidly the flicker test ability of digitizing transforming plant energy quality end is assessed.

Beneficial effect of the present invention is:

1. solve the technical matters affecting the true reflection of electric network terminal detection data that the manual flickering precision detecting digital electric power quality monitoring terminal one by one in prior art causes, propose the flickering accuracy checking method of the digital transformer substation electric energy quality monitoring terminal successively decreased step by step based on flickering undulate quantity.

2. the creationary flicker detection signal devising undulate quantity and successively decrease step by step: front 3.5% time period fluctuation size is 0.25%, 8.8HZ sine modulation ripple; Following 7.5% time period undulate quantity is 8.8HZ sine modulation ripple; Ensuing 60% time period undulate quantity becomes sine modulation ripple becomes 8.0HZ; 29% last time period undulate quantity is sine modulation wave frequency reverts to 8.8HZ.Totally four time periods, 10 minutes.Within following 10 minutes, signal repeats four time periods above again, and signal length has 20 minutes altogether.

3. whether the detection signal that technical scheme of the present invention proposes can screen out monitoring terminal according to IEC standard, accuracy of detection and dynamic flicker detection ability.Only need the constantly undulate quantity of change and a detection signal for vibration frequency, just can assess the flicker test ability of digitizing transforming plant energy quality end easily and quickly.

One of ordinary skill in the art will appreciate that all or part of flow process realized in above-described embodiment method, the hardware that can carry out instruction relevant by computer program has come, described program can be stored in general computer read/write memory medium, this program, when performing, can comprise the flow process of the embodiment as above-mentioned each side method.Wherein, described storage medium can be magnetic disc, CD, read-only store-memory body (Read-Only Memory, ROM) or random store-memory body (Random AccessMemory, RAM) etc.

Those skilled in the art can also recognize that the various functions that the embodiment of the present invention is listed are the designing requirements realizing depending on specific application and whole system by hardware or software.Those skilled in the art for often kind of specifically application, can use the function described in the realization of various method, but this realization can should not be understood to the scope exceeding embodiment of the present invention protection.

Apply specific embodiment in the present invention to set forth principle of the present invention and embodiment, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping; Meanwhile, for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (10)

1. a flickering accuracy checking method for digital electric power quality monitoring terminal, is characterized in that, described method specifically comprises:

Send to digital electric power quality monitoring terminal and meet International Electrotechnical Commission IEC61850-9-2 required standard signal;

Described digital electric power quality monitoring terminal is sampled to described standard signal, and exports industrial manufacturing standard message MMS message;

According to the minute data of described MMS message determination Short Term Flicker index;

The Short Term Flicker measured value of described digital electric power quality monitoring terminal is determined according to the minute data of described Short Term Flicker index.

2. method according to claim 1, is characterized in that, described standard signal is: the fluctuation size of front 3.5% time period is 0.25%, the sine modulation ripple of 8.8Hz; The undulate quantity of time period of following 7.5% is the sine modulation ripple of 8.8Hz; The undulate quantity of ensuing 60% time period is sine modulation ripple is 9.5Hz; The undulate quantity of last 29% time period is sine modulation wave frequency is 8.8Hz, totally four time periods, 10 minutes, within ensuing 10 minutes, repeats four time periods above again, and the length of standard signal is 20 minutes.

3. method according to claim 2, is characterized in that, the minute data according to described MMS message determination Short Term Flicker index specifically comprises:

MMS message described in parsing;

The minute data of Short Term Flicker index is extracted in MMS message analytically.

4. method according to claim 3, is characterized in that, determines that the Short Term Flicker measured value of described digital electric power quality monitoring terminal specifically comprises according to the minute data of described Short Term Flicker index:

First non-vanishing value is extracted in Short Term Flicker measured value from the minute data table of described Short Term Flicker index;

Determine the moment that described first non-vanishing value is corresponding to be called for the first moment;

The first described moment is added 10 minutes and obtained for the second moment;

Determine the Short Term Flicker measured value that described second moment is corresponding.

5. the method according to claim 2 or 4, is characterized in that, after the Short Term Flicker measured value determining described digital electric power quality monitoring terminal, described method also comprises:

Obtain the Short Term Flicker theoretical value of described standard signal;

Described Short Term Flicker theoretical value and described Short Term Flicker measured value are compared, obtains comparison result;

Whether the digital electric power quality monitoring terminal described in judging according to described comparison result meets IEC standard.

6. a flickering precision detection system for digital electric power quality monitoring terminal, is characterized in that, described system specifically comprises:

Standard signal dispensing device, meets International Electrotechnical Commission IEC61850-9-2 required standard signal for sending to digital electric power quality monitoring terminal;

Described digital electric power quality monitoring terminal, for sampling to described standard signal, and exports industrial manufacturing standard message MMS message;

Minute data determining device, for the minute data according to described MMS message determination Short Term Flicker index;

Short Term Flicker measured value determining device, for determining the Short Term Flicker measured value of described digital electric power quality monitoring terminal according to the minute data of described Short Term Flicker index.

7. system according to claim 6, is characterized in that, described standard signal is: the fluctuation size of front 3.5% time period is 0.25%, the sine modulation ripple of 8.8Hz; The undulate quantity of time period of following 7.5% is the sine modulation ripple of 8.8Hz; The undulate quantity of ensuing 60% time period is sine modulation ripple is 9.5Hz; The undulate quantity of last 29% time period is sine modulation wave frequency is 8.8Hz, totally four time periods, 10 minutes, within ensuing 10 minutes, repeats four time periods above again, and the length of standard signal is 20 minutes.

8. system according to claim 7, is characterized in that, described minute data determining device specifically comprises:

Parsing module, for resolving described MMS message;

Minute data extraction module, for extracting the minute data of Short Term Flicker index in the MMS message after analytically.

9. system according to claim 8, is characterized in that, described Short Term Flicker measured value determining device specifically comprises:

Extraction module, for extracting in Short Term Flicker measured value first non-vanishing value in the minute data table from described Short Term Flicker index;

First moment determination module, for determining the moment that described first non-vanishing value is corresponding, was called for the first moment;

Second moment determination module, obtained for the second moment for the first described moment is added 10 minutes;

Short Term Flicker measured value determination module, for determining the Short Term Flicker measured value that described second moment is corresponding.

10. the system according to claim 7 or 9, is characterized in that, described system also comprises:

Short Term Flicker theoretical value acquisition device, for obtaining the Short Term Flicker theoretical value of described standard signal;

Comparison device, for described Short Term Flicker theoretical value and described Short Term Flicker measured value being compared, obtains comparison result;

Whether judgment means, meet IEC standard for the digital electric power quality monitoring terminal described in judging according to described comparison result.