CN113946959A - Voltage sag data segment extraction method - Google Patents
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Abstract
A voltage sag data segment extraction method comprises the following steps: processing the wave recording data segment by using S transformation, and acquiring the number n of mutation points and mutation moments according to the content of the high-frequency components at different moments; for asymmetric faults, extracting a voltage sag data segment by combining mutation time, wherein beta is beta at the voltage sag starting time of the wave recording data segmentStarting point< epsilon, beta at the end of the voltage sag of said recording data sectionPowder< ε; and for symmetrical faults, extracting a sag data segment by combining with the sudden change time, wherein at the voltage sag starting time of the wave recording data segment, the voltage effective value of each previous period is larger than that of the next period, and at the voltage sag finishing time of the wave recording data segment, the voltage effective value of each previous period is smaller than that of the next period. It can not only effectively distinguish different voltage dipsAnd the sag data segments of different sag events can be extracted under the condition of wave recording, so that a data basis is provided for the more in-depth study of voltage sag.
Description
Technical Field
The invention relates to the technical field of voltage sag fault processing, in particular to a voltage sag data segment extraction method.
Background
With the rapid development of modern industry in China and the great change of the electrical load structure of an industrial park, more and more accidents are caused by the problem of power quality, and voltage sag is paid much attention as one of the most main problems in the problem of power quality. In order to monitor voltage sags in sensitive load concentration areas such as industrial parks, more and more monitoring terminals are deployed.
The existing wave recording condition dividing method only distinguishes normal wave recording data and special wave recording data, and does not subdivide the special wave recording data, so that the engineering applicability of the method is not strong. The sag data segment is an original data segment which can represent a single sag event in a sag waveform, namely data between the start point and the stop point of the single sag. The existing extraction method of the sag data segment can only extract normal wave recording data, and for special wave recording data, part of documents directly regard the special wave recording data as 'bad data', so that data waste is caused.
Disclosure of Invention
Through investigating and analyzing the wave recording principle of voltage sag monitoring terminals at home and abroad and the actual wave recording of a plurality of provincial level power quality monitoring systems, the inventor finds that: a plurality of complete or incomplete pause data segments may exist in a pause event recording file, and missing parts in the incomplete data segments cannot exist between the beginning and the end of recording; and there is little single or two phase data loss.
Based on the above research, the present invention aims to provide a method for extracting voltage sag data segments, so as to improve the accuracy of voltage sag data segment extraction.
The technical scheme of the invention is as follows:
a voltage sag data segment extraction method comprises the following steps:
processing the wave recording data segment by using S transformation, and acquiring the number n of mutation points and mutation moments according to the content of the high-frequency components at different moments;
for asymmetric faults, unbalance is measured
In the formula of UA、UB、UCRepresenting the effective value, U, of the three-phase voltageavgThe average value of the three-phase voltage effective values is represented;
if beta is larger than or equal to epsilon and epsilon is an unbalance threshold, temporarily dropping the wave recording data segment;
extracting a voltage sag data segment by combining the mutation time, wherein beta is the initial time of the voltage sag of the wave recording data segmentStarting point< epsilon, beta at the end of the voltage sag of said recording data sectionPowder＜ε；
For the symmetrical fault, the voltage effective value of the previous period of each phase is greater than the voltage effective value of the next period, or the voltage effective value of the previous period of each phase is less than the voltage effective value of the next period, and the wave recording data segment is temporarily dropped;
and extracting a sag data segment by combining with the sudden change time, wherein at the voltage sag starting time of the wave recording data segment, the voltage effective value of each previous period is larger than that of the next period, and at the voltage sag finishing time of the wave recording data segment, the voltage effective value of each previous period is smaller than that of the next period.
Preferably, if the recording data segment includes a voltage sag event, the recording data segment is set to include a voltage sag eventThe number of events is m, and the effective value of the previous period of the first catastrophe point of each phase is Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 1, Ufpa>Ufla，Ufpb>UflbAnd U isfpc>UflcOr n is 1, betafp<Epsilon and betafl>If m is equal to 1, intercepting data between the catastrophe point moment and the wave recording termination moment as an incomplete sag data segment; if n is 1, Ufpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr n is 1, betafp>Epsilon and betafl<And e, if m is equal to 1, intercepting data between the wave recording starting moment and the catastrophe point moment as an incomplete sag data segment.
Preferably, if the wave recording data segment contains voltage sag events, the number of the voltage sag events contained in the wave recording data segment is m, and effective values of a period before a first catastrophe point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpOne cycle after the first mutation point is not usedDegree of equilibrium betaflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2, Ufpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr n is 2, betafp<ε，βfl>ε，βlp>Epsilon and betall<If the m is equal to 1, intercepting data between the mutation points as a complete sag data segment; if n is 2, satisfy Ufpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr satisfy betafp>ε，βfl<ε，βlp<Epsilon and betall>And epsilon, if m is 2, respectively intercepting data between the wave recording starting time and the first catastrophe point and data between the last catastrophe point and the wave recording ending time as incomplete sag data segments.
Preferably, if the wave recording data segment contains voltage sag events, the number of the voltage sag events contained in the wave recording data segment is m, and effective values of a period before a first catastrophe point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2 xk-1 and k is more than or equal to 2, then m is k + 1; if U isfpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr βfp>Epsilon and betafl<E, intercepting data between the wave recording start time and the first catastrophe point as an incomplete sag data segment, and sequentially intercepting data between n-2 × j and n-2 × j +1 (j-1, …, k) as an complete sag data segment; if U islpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr βlp<Epsilon and betall>And e, sequentially intercepting data between n and j and n and 2 × j (j and 1, …, k) as a complete pause data segment, and intercepting data between the last mutation point and the wave recording end time as an incomplete pause data segment.
Preferably, if the wave recording data segment contains voltage sag events, the number of the voltage sag events contained in the wave recording data segment is m, and effective values of a period before a first catastrophe point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2 xk, k is 2 or more, Ufpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr n is 2 xk, k is 2, betafp>ε，βfl<ε，βlp<Epsilon and betall>E, if m is k +1, respectively intercepting data between the wave recording starting time and the first mutation point and data between the last mutation point and the wave recording ending timeSequentially intercepting data between n-2 xj and n-2 xj +1 (j-1, …, k-1) as a complete sag data segment; if n is 2 xk, k is 2 or more, Ufpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr n is 2 xk, k is 2, betafp<ε，βfl>ε，βlp>Epsilon and betall<And e, then m is k, and sequentially intercepting data between n and j and n and 2 × j (j is 1, …, k) as a complete pause data segment.
The invention has the beneficial effects that:
1. the invention utilizes S transformation to detect the number of mutation points and mutation time, then judges the wave recording condition through the relation of three-phase unbalance and effective values of a period before and after the mutation points, and can extract the sag data section by combining the mutation time detected by the S transformation. The method can effectively distinguish different voltage sag wave recording conditions, extract sag data sections of different sag events and provide a data basis for deeper research of sag. Meanwhile, the method eliminates the interference of normal waveforms, reduces the calculated amount for the sag deep research and improves the accuracy.
Drawings
Fig. 1 is a schematic diagram of extracting sag data segments for different recording situations.
Detailed Description
The present invention is described below in terms of embodiments in conjunction with the accompanying drawings to assist those skilled in the art in understanding and implementing the present invention. Unless otherwise indicated, the following embodiments and technical terms therein should not be understood to depart from the background of the technical knowledge in the technical field.
The method for judging the wave recording condition based on the S transformation detects the number of the mutation points and the mutation time, and judges the wave recording condition by utilizing the three-phase unbalance degree and the effective value relation of a period before and after the mutation points. Aiming at asymmetric faults, the deviation degree of three-phase voltage effective values is expressed by utilizing the unbalance degree beta, the calculation formula is shown as (2), the epsilon represents an unbalance degree threshold value, the threshold value coefficient can be determined according to national standards, and the relation between the beta and the epsilon is compared, so that whether the sag occurs or not can be obtained. If beta < epsilon, the data segment is not temporarily dropped, otherwise, the data segment is temporarily dropped. For symmetry faults, whether sag occurs or not can be known by using the effective value relation of a period before and after each phase catastrophe point. If the effective value of the previous period of each phase is larger than the effective value of the next period, namely the period after the mutation point of the data segment contains sag; otherwise, the period before the mutation point of the data segment comprises sag. And (4) knowing the wave recording condition according to the fact that the complete sag data segment is normal-sag-normal, and extracting the sag data segment by combining the mutation moment.
In the above formula UA、UB、UCRepresenting the effective value, U, of the three-phase voltageavgAnd represents the average value of the effective values of the three-phase voltage.
The specific implementation process is as follows:
(1) and (5) detecting a change point. Because the voltage sag waveform has a mutation point, the S transformation is suitable for analyzing a non-stationary signal with mutation property, and has the advantages of intuition and the like in the aspect of feature extraction result display. This patent application S transform is as the main algorithm of feature extraction, and the implementation process: firstly, an S-mode matrix is formed by utilizing S transformation, then high-frequency components in the S-mode matrix are extracted, and the number of mutation points and mutation moments are obtained according to the contents of the high-frequency components at different moments.
The S transformation has the basic principle:
discrete S transformation of signal h (t) to (k 0, 1, 2, L N-1, n 0, 1, 2, L N-1):
in the above formula, T is a time interval, T is a total time, and N is the number of sampling points.
If n is 0
The result of the S change is a two-dimensional matrix, and the result is obtained by taking the modulus value of each element of the matrix:
the row vector of the S-mode matrix represents the amplitude content of the discrete signal at different moments on a certain frequency, and the column vector of the S-mode matrix represents the content of the discrete signal at different frequencies at a certain moment.
Note: the S-transform has a parameter n in the basic principle different from the number of discontinuities n.
(2) Dividing the wave recording condition and extracting the sag data segment. At present, the wave recording situations of the voltage sag event can be divided into 7 types, wherein the normal wave recording situation is 1 type, the special wave recording situation is 6 types, and the sag data segment extraction is described by taking fig. 1 as an example:
in fig. 1, since the number of mutation points of each phase is the same, assuming that the number of mutation points of phase a detected by S transformation is n, the number of sag events to be determined is m (m)>0) The effective value of the previous period of the first catastrophe point of each phase is Ufpa、Ufpb、UfpcThe effective value of the next cycle period is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、Ulpc(ii) a The effective value of the latter cycle is Ulla、Ullb、Ullc. The unbalance degree beta is calculated by the formula (2)fp、βfl、βlp、βll。
If n is 1, recording incomplete data is obtained, and m is 1. On the basis that n is 1, if Ufpa>Ufla，Ufpb>UflbAnd U isfpc>UflcOr βfp<Epsilon and betafl>Epsilon, the recording data only contains the beginning section of the sag, as shown in fig. 1(a), the data between the time of the discontinuity point and the termination of the recording is intercepted as the data section of the sag, as shown in fig. 1(a)A red dotted line portion; if U isfpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr βfp>Epsilon and betafl<ε, the recording data contains only the dip end segment, as shown in FIG. 1 (b). And intercepting data between the wave recording starting moment and the catastrophe point moment as a dip data segment as a red dotted line part in the figure 1 (b).
If n is 2, satisfy Ufpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr satisfy betafp<ε，βfl>ε，βlp>Epsilon and betall<And epsilon, namely, the normal recording data, wherein m is 1 as shown in fig. 1 (c). And intercepting data between the mutation points as a dip data segment, as shown in a black dotted line part in fig. 1 (c). If n is 2, satisfy Ufpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr satisfy betafp>ε，βfl<ε，βlp<Epsilon and betall>Epsilon is a plurality of dip events contained in the recording data, and the first and last dip events are not completely recorded, wherein m is 2. And respectively intercepting data between the wave recording starting moment and the first catastrophe point and data between the last catastrophe point and the wave recording ending moment as a sag data segment of the incomplete wave recording.
If n is 2 xk-1 (k is more than or equal to 2), the multiple dip events are included in the recording data, and one dip event does not completely record, in which case m is k + 1. On the basis of n ═ 2 xk-1, if Ufpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr βfp>Epsilon and betafl<ε, the first sag event contains only the end segment, as shown in FIG. 1 (d). Intercepting the recording start time to the first mutation point as an incomplete sag data segment, as shown in fig. 1(d), sequentially intercepting n-2 × j and n-2 × j +1 (j)1, …, k) as a dip data segment of a complete dip event, as shown in fig. 1(d) in black dashed lines; if U islpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr βlp<Epsilon and betall>Epsilon, the last sag event only contains a sag start segment, as shown in fig. 1(e), sequentially intercepting data between n ═ j and n ═ 2 × j (j ═ 1, …, k) as a sag data segment of the complete sag event, as shown in the black dotted line portion in fig. 1 (e); and intercepting data between the last mutation point and the wave recording end time as an incomplete pause data segment, as shown in a red dotted line part in fig. 1 (e).
If n is 2 xk (k ≧ 2), U is satisfiedfpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr satisfy betafp>ε，βfl<ε，βlp<Epsilon and betall>Epsilon is a plurality of dip events contained in the recording data, and none of the first and last dip events is completely recorded, where m is k +1, as shown in fig. 1 (f). Respectively intercepting data between the beginning time of recording and the first mutation point and data between the last mutation point and the end time of recording as a sag data segment of incomplete recording, such as a red dotted line part in fig. 1 (f); sequentially intercepting data between n-2 × j and n-2 × j +1 (j-1, …, k-1) as a sag data segment of a complete sag event, as shown in fig. 1(f) by a black dashed line.
If n is 2 xk (k ≧ 2), U is satisfiedfpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr satisfy betafp<ε，βfl>ε，βlp>Epsilon and betall<Epsilon, i.e. the recorded wave data contains multiple dip events and all are completely recorded, when m is k, as shown in fig. 1 (g). Sequentially intercepting data between n-j and n-2 × j (j-1, …, k) as a pause data segment of a complete pause event, as shown in fig. 1(g) blackAnd dotted line portion.
The invention is described in detail above with reference to the figures and examples. It should be understood that in practice the description of all possible embodiments is not exhaustive and that the inventive concepts are described herein as far as possible by way of illustration. Without departing from the inventive concept of the present invention and without any creative work, a person skilled in the art should, in all of the embodiments, make optional combinations of technical features and experimental changes of specific parameters, or make a routine replacement of the disclosed technical means by using the prior art in the technical field to form specific embodiments, which belong to the content implicitly disclosed by the present invention.
Claims (5)
1. A voltage sag data segment extraction method is characterized by comprising the following steps:
processing the wave recording data segment by using S transformation, and acquiring the number n of mutation points and mutation moments according to the content of the high-frequency components at different moments;
for asymmetric faults, unbalance is measured
In the formula of UA、UB、UCRepresenting the effective value, U, of the three-phase voltageavgThe average value of the three-phase voltage effective values is represented;
if beta is larger than or equal to epsilon and epsilon is an unbalance threshold, temporarily dropping the wave recording data segment;
extracting a voltage sag data segment by combining the mutation time, wherein beta is the initial time of the voltage sag of the wave recording data segmentStarting point< epsilon, beta at the end of the voltage sag of said recording data sectionPowder＜ε；
For the symmetrical fault, the voltage effective value of the previous period of each phase is greater than the voltage effective value of the next period, or the voltage effective value of the previous period of each phase is less than the voltage effective value of the next period, and the wave recording data segment is temporarily dropped;
and extracting a sag data segment by combining with the sudden change time, wherein at the voltage sag starting time of the wave recording data segment, the voltage effective value of each previous period is larger than that of the next period, and at the voltage sag finishing time of the wave recording data segment, the voltage effective value of each previous period is smaller than that of the next period.
2. The method according to claim 1, wherein if the recording data segment contains voltage sag events, the recording data segment is defined to contain m number of voltage sag events, and the effective values of the period before the first mutation point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 1, Ufpa>Ufla，Ufpb>UflbAnd U isfpc>UflcOr n is 1, betafp<Epsilon and betafl>If m is equal to 1, intercepting data between the catastrophe point moment and the wave recording termination moment as an incomplete sag data segment; if n is 1, Ufpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr n is 1, betafp>Epsilon and betafl<And e, if m is equal to 1, intercepting data between the wave recording starting moment and the catastrophe point moment as an incomplete sag data segment.
3. The voltage sag data segment extraction of claim 1The method is characterized in that if the wave recording data section contains voltage sag events, the number of the voltage sag events contained in the wave recording data section is set to be m, and effective values of a period before a first catastrophe point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2, Ufpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr n is 2, betafp<ε，βfl>ε，βlp>Epsilon and betall<If the m is equal to 1, intercepting data between the mutation points as a complete sag data segment; if n is 2, satisfy Ufpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr satisfy betafp>ε，βfl<ε，βlp<Epsilon and betall>And epsilon, if m is 2, respectively intercepting data between the wave recording starting time and the first catastrophe point and data between the last catastrophe point and the wave recording ending time as incomplete sag data segments.
4. The method of claim 1, wherein if the recording data segment includes a voltage sag event, the recording data segment is configured to include a voltageThe number of sag events is m, and the effective value of the previous period of the first catastrophe point of each phase is Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2 xk-1 and k is more than or equal to 2, then m is k + 1; if U isfpa<Ufla，Ufpb<UflbAnd U isfpc<UflcOr βfp>Epsilon and betafl<E, intercepting data between the wave recording start time and the first catastrophe point as an incomplete sag data segment, and sequentially intercepting data between n-2 × j and n-2 × j +1 (j-1, …, k) as an complete sag data segment; if U islpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr βlp<Epsilon and betall>And e, sequentially intercepting data between n and j and n and 2 × j (j and 1, …, k) as a complete pause data segment, and intercepting data between the last mutation point and the wave recording end time as an incomplete pause data segment.
5. The method according to claim 1, wherein if the recording data segment contains voltage sag events, the recording data segment is defined to contain m number of voltage sag events, and the effective values of the period before the first mutation point of each phase are respectively Ufpa、Ufpb、UfpcThe effective value of the first catastrophe point of each phase and the cycle period of each phase is Ufla、Uflb、Uflc(ii) a Effective value U of period before last catastrophe point of each phaselpa、Ulpb、UlpcThe effective value of a cycle period after the last catastrophe point of each phase is Ulla、Ullb、Ullc(ii) a Respectively calculating the unbalance degree beta of the previous period of the first mutation point by using the formula (1)fpA cycle period imbalance beta after the first discontinuityflThe unbalance beta of the previous period of the last mutation pointlpA cycle period imbalance beta after the last discontinuityll(ii) a If n is 2 xk, k is 2 or more, Ufpa<Ufla，Ufpb<Uflb，Ufpc<Uflc，Ulpa>Ulla，Ulpb>UllbAnd U islpc>UllcOr n is 2 xk, k is 2, betafp>ε，βfl<ε，βlp<Epsilon and betall>Respectively intercepting data between the wave recording starting time and the first catastrophe point and data between the last catastrophe point and the wave recording ending time as an incomplete sag data segment, and sequentially intercepting data between n-2 xj and n-2 xj +1 (j-1, …, k-1) as an complete sag data segment; if n is 2 xk, k is 2 or more, Ufpa>Ufla，Ufpb>Uflb，Ufpc>Uflc，Ulpa<Ulla，Ulpb<UllbAnd U islpc<UllcOr n is 2 xk, k is 2, betafp<ε，βfl>ε，βlp>Epsilon and betall<And e, then m is k, and sequentially intercepting data between n and j and n and 2 × j (j is 1, …, k) as a complete pause data segment.
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