CN104467186A - Full network fault recording data parameter-free accurate synchronizing method - Google Patents

Abstract

The present invention relates to a parameter-free and accurate synchronization method for fault wave recording data of the whole network, which comprises the following steps: (1) acquiring wave recording data of each wave recorder through a wave recording data acquisition module, and storing the acquired wave recording data in a data center Middle; (2) Obtain the clock status of each oscilloscope through the acquisition module of the oscilloscope clock state, and obtain the time deviation Td of each oscilloscope; (3) Automatically correlate the wave recording data through the module for multiple recording data performing association; (4) synchronizing the multiple associated wave recording data obtained by the wave recording data automatic association module through the wave recording data automatic synchronization module. The method makes full use of wave recording data from multiple wave recorders, does not need system parameters, and realizes automatic and precise synchronization of associated wave recording data. At the same time, the method is realized in the networked system of the wave recorder, and the operation is simple and convenient, so that the dispatcher can grasp the fault situation more timely, accurately and intuitively.

Description

A No-parameter Accurate Synchronization Method of Fault Recording Data in the Whole Network

technical field

The invention belongs to the technical field of power grid fault monitoring, and relates to a method for synchronizing fault recording data, in particular to a parameter-free and precise synchronization method for fault recording data of the entire network.

Background technique

With the increase of unattended substations, the channel of distributed fault recording data remote transmission and the solution of the protocol problem, the distributed fault recorder (recorder) is interconnected through the data network and the fault recording data (recording data ) to the control center has been implemented in many regional power grids. The wave recorder networking system solves the problem that the traditional wave record data needs to be retrieved from the substation, and the accident analysis is relatively lagging. It consists of the master station system located in the control center, the wave recorder located in the substation and the information transmission system. The main station system is connected to the wave recorders of multiple substations through the dispatch data network, and is responsible for collecting the operation and fault information of the primary and secondary equipment connected to each wave recorder.

When a fault occurs, due to the large fault disturbance, multiple wave recorders in multiple substations near the fault occurrence point will start to record waves and send them to the master station system at the same time. Multiple wave recording data files. Utilizing these recorded wave data can not only carry out comprehensive analysis on faults, but also carry out other applications. For example, the measurement and calculation of transmission line parameters, grid fault diagnosis, accurate fault location and protection characteristic analysis, etc. The first step in using these wave recording data is to correlate these data files from each wave recorder according to the time when the fault occurred, and eliminate the irrelevant wave recording data before and after the fault occurred. As one of the most important fault information, the clock can accurately reflect the time when the fault occurs and the time when the fault ends. At present, although substations above 220kV are equipped with a unified time service system, some equipment using pulse time synchronization methods, due to the poor reliability of pulse signals, their clocks often make mistakes, and it is currently impossible for multiple substation wave recorders to achieve accurate time synchronization. Fully guaranteed. Therefore, when performing fault analysis, for simple faults, the staff can analyze the fault waveforms of multiple substations in the main station, and manually correlate according to the change of characteristic electrical quantities and the action of the protective circuit breaker. However, for some complex faults that occur in a short period of time, each substation may record multiple wave recording data in a short period of time, and it is difficult to judge the correlation of multiple wave recording data without an accurate clock. Therefore, in order to accurately analyze faults, multiple recording data collected by multiple recorders are required to perform effective automatic correlation and data synchronization according to each fault.

In the data synchronization method, for the data of different substations, the out-of-synchronization time can be accurately calculated theoretically by using the voltage and current data before the fault and the parameters of the tie line between the two substations. However, in practical applications, on the one hand, because the precise parameters of the transmission line are difficult to obtain, even the measured values vary, which introduces a large error to the data synchronization. On the other hand, the oscilloscope cannot be equivalent to the relay protection equipment in terms of management, and its parameters are less dependable.

Therefore, finding a data synchronization method that is more accurate and does not depend on system parameters is an important step in the practical application of wave recording data synchronization in multiple substations, and it is also urgently needed in current grid fault monitoring.

Contents of the invention

The present invention aims to overcome the deficiencies of the prior art, and provides a parameter-free and accurate synchronization method for fault recording data of the entire network. Automatic and precise synchronization of associated recording data.

In order to achieve the above object, the present invention provides the following technical solutions: a method for accurately synchronizing fault recording data of a whole network without parameters, which includes the following steps: (1) obtaining the recording data of each recording device through the recording data acquisition module, And the wave recording data that obtains is stored in the data center; (2) obtain the clock state of each wave recorder by the wave recorder clock state acquisition module, and obtain the time deviation T _d of each wave recorder; (3) pass The wave recording data automatic association module correlates a plurality of wave recording data; (4) the wave recording data automatic synchronization module synchronizes the multiple associated wave recording data obtained by the wave recording data automatic association module.

Further, wherein, the step (3) specifically includes: a. The data center obtains the time deviation T _d , and corrects the time of the wave recording data of each wave recorder based on the time deviation T _d ; b. After the correction, check whether there is any fault time associated with other wave recording data, and assign its fault number to this wave recording data; if there is no wave recording data associated with its time, it is considered that this wave recording data reflects one time If there is a new fault, set a new fault number for it.

Further, wherein, the step (4) specifically includes: a, retrieving the recorded wave data in the data center according to the fault number, and synchronizing different recorded wave data of the same line; One cycle is analyzed, if the fault occurs outside the tie line area of the two substations, the non-recorded data synchronization method is used to automatically align the data, and the out-of-synchronization time is recorded; c. If the fault occurs on one of the double-circuit tie lines of the two substations, Then judge whether the other circuit is faulty, if there is no fault, then complete the synchronization through the wave recording data of another circuit; d, if the line is a single circuit, then according to the calculated synchronization time of the wave recording data of other substations, find the detour The tie line channel is used to calculate the synchronization time to achieve synchronization; e. If the line is a single-circuit line and there is no detour tie line channel, the data before the failure of the non-fault line is used to approximate synchronization.

Further, wherein, the synchronization method in a in the step (4) is: at first, according to the configuration of the substation oscilloscope, extract the common signal of each oscilloscope data; secondly, utilize the full-cycle Fourier transform to extract the fault The angle difference between the front and rear public signal sine waves is used to calculate the out-of-sync time of each oscilloscope; finally, according to the out-of-sync time, the rest of the non-common signal data are synchronized.

The method for associating and synchronizing wave recording data in multiple substations of the present invention first detects the clock deviation of the wave recorders in the networked system of wave recorders in which the clock deviations of the wave recorders are relatively large, and on this basis, realizes multiple wave recording Automatic correlation of data. It makes full use of the wave recording data from multiple wave recorders, does not require system parameters, and realizes automatic and precise synchronization of the associated wave recording data. This method is realized in the networked system of the wave recorder, which is simple and convenient to operate, enables dispatchers to grasp the fault situation more timely, accurately and intuitively, and provides deeper data support for the application of power grid fault analysis on this basis.

Description of drawings

Fig. 1 is a flow chart of the method for accurately synchronizing fault recording data of the whole network without parameters according to the present invention.

Figure 2 is a schematic diagram of a typical oscilloscope networking system.

Fig. 3 is a schematic diagram of the principle and process of the time deviation detection of the oscilloscope.

Fig. 4 is a schematic diagram of a local power grid topology.

Figure 5 is the lumped parameter model of the transmission line.

Fig. 6 is a flow chart of recording data association and synchronization.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, and the contents of the specific embodiments are not intended to limit the scope of protection of the present invention.

Fig. 1 shows a flow chart of the method for accurately synchronizing fault recording data of the whole network without parameters according to the present invention. As shown in Fig. 1, the parameter-free accurate synchronization method of fault recording data in the whole network of the present invention first obtains the recording data of each recording device through the recording data acquisition module, and stores the obtained recording data in the data center. Specifically, the master station of the oscilloscope networking system acquires the oscilloscope data of each oscilloscope through the acquisition module, and the data center is responsible for storing the data and providing it to the engineer station.

Secondly, the clock status of each oscilloscope is obtained through the acquisition module of the oscilloscope clock state, and the time deviation Td of each oscilloscope is obtained. Specifically, the master station of the oscilloscope networking system adopts a periodic inspection method to obtain the clock status of each oscilloscope, and obtains the time deviation T _d of the oscilloscope. In a short period of time, it is considered that this time deviation is not changing. The clock status acquisition module of the oscilloscope is responsible for inquiring and calculating the clock status of the oscilloscope, and storing it in the data center. Meanwhile, the engineer station can query the clock status of the entire network at any time.

Taking the typical wave recorder networking system shown in Figure 2 as an example, if a fault occurs at point F between substation _1T1 and substation _2T2 , both substations will record the fault data, and the wave recorder dispatch data network will send the wave record data The first step of synchronizing the wave recording data _of the two substations is to carry out the automatic association of the wave recording data of the two substations.

After a fault occurs in the power grid, the wave recording data includes fault analog data, switching value action signal and fault occurrence time. Due to the error of time synchronization, the time in the wave recording data is inaccurate, but the time of the wave recording master station is synchronized by a unified clock, and the time is accurate. The clocks of each oscilloscope and oscilloscope recording master station may have deviations of various sizes, reaching hours or even days.

Compared with each wave recorder, the clock of the wave recording master station is unique, and the key to automatic association of wave recording data is to detect the deviation between the time of each wave recorder and the clock of the wave recording master station. As shown in Figure 2, two adjacent substations communicate with the wave recording master station through the dispatching data network, and the wave recording master station can be used to detect the time of the wave recorders distributed in each substation.

According to the above analysis, the time deviation between the wave recorders is different and irregular, but the clock of the wave recorder master station is accurate and unique. If the time deviation of each wave recorder relative to the wave recording master station can be obtained in real time, the time deviation can be used to calibrate the fault occurrence time in the wave recording data after a fault occurs, so as to realize the time correlation of each wave recording data.

The principle and process of obtaining the time deviation T _d of each wave recorder by the wave recording master station are shown in Figure 3. Among them, (1) the acquisition module of the wave recording master station sends a request clock message to the wave recorder at time T _A1 . (2) The oscilloscope receives the request clock message at _TB1 time, and sends a response message to the master station at _TB2 time after △t _B response time. (3) The acquisition module of the wave recording master station receives the response message sent by the wave recorder, and calculates the time deviation T _d . The calculation method is as follows:

Among them, the transmission delay is: $\mathrm{\Δt}=\frac{\mathrm{\Δ}{t}_A-\mathrm{\Δ}{t}_B}{2}---\left(1\right)$

Then, the time offset is: $T_d=T_{B1}-T_{A1}-\mathrm{\Δt}=T_{B1}-T_{A1}-\frac{\mathrm{\Δ}{t}_A-\mathrm{\Δ}{t}_B}{2}---\left(2\right)$

Since the response speed of the oscilloscope is very fast, generally at the microsecond level, we can ignore △t _B , let T _B1 = T _B2 = T _B , and substitute it into the above formula to get: (3)

The time deviation of each oscilloscope can be obtained in real time through periodic inspection at the main wave recording station. Assuming that the main wave recording station detects a failure at time T, query the time of the wave recorder in substation 1 of the inspection period at time T The deviation is T _1d , and the fault occurrence time recorded by the oscilloscope is T ₁ , then after correction, the fault time collected by the oscilloscope of substation 1 is:

T _1F =T ₁ -T _1d (4)

Similarly, after a fault occurs, time correction can be performed on the wave recording data sent by the wave recorder in substation 2. After time correction, the wave recording data can be correlated by comparing the fault time of the data collected by each wave recorder. That is, if the failure times of the oscillographic data are the same, they are related oscillographic data. Affected by the length of the inspection cycle and the response time of the oscilloscope, this time deviation is at the millisecond level, but it is not completely accurate. It is impossible to use this time correction result to accurately synchronize the oscilloscope data. Therefore, the next step is to find a method for synchronizing wave recording data.

As shown in Figure 4, assuming that the fault occurs on the line L1, the multiple recorders at both ends of the line L1 and its adjacent substations (Station 1, Station 2, Station 3, etc.) will start to record waves, and record waves The data files are sent to the fault recording master station. According to the aforementioned method, the fault recording master station correlates the recording data from multiple recorders according to the current fault. Afterwards, the fault recording master station reads out each data file according to the COMTRADE format and reads out the data recorded by each recording channel of each recording data. Wave data can be synchronized with an error of one cycle within one cycle before and after the fault occurs. Next, what needs to be done is precise synchronization of the data. According to the difference of the substation where the wave recorder is located, the wave recording data is divided into data from different wave recorders in the same substation and data from different wave recorders in the same substation. Therefore, data synchronization occurs in two steps. The first step is to synchronize data from different oscilloscopes in the same substation, and the second step is to synchronize data from different oscilloscopes in different substations.

1. Synchronization of wave recording data in the same substation

At present, for substations with different voltage levels or substations with many outgoing line intervals, multiple oscilloscopes are actually equipped to complete the monitoring of multiple intervals and multiple devices. The main primary equipment of the substation can be divided into three categories: busbar, line and main transformer. For line intervals connected to different oscilloscopes, the bus voltage collected by each interval is its common signal. If there is a separate main transformer recorder, the voltage on each side of the main transformer and the bus voltage on each side are also public signals. If there is a separate bus wave recorder, the current of each bus outlet interval and the current of the line interval are also common signals. Data synchronization between different oscilloscopes can be realized by using these common signals. The synchronization method and steps are as follows: (1) Extract the common signal of each recorder data according to the configuration of the recorder in the substation. (2) Use the full-cycle Fourier transform to extract the angle difference between the common signal sine waves before and after the fault, and calculate the out-of-sync time of each oscilloscope. (3) Synchronize the remaining non-common signal data according to the out-of-synchronization time.

2. Wave recording data synchronization between different substations

It can be seen from Figure 4 that when a fault occurs, the associated data files transmitted to the wave recording master station include not only the electrical quantity data on both sides of the line L1, but also the electrical quantities at both ends of the line L2, line L3, and line L4. data. Since the data from the same substation has already been synchronized, the out-of-sync time of the data at both ends of the line L1 is the same as the out-of-sync time of the data at both ends of the line L2. By calculating the asynchronous time of line L2, the wave recording data of station 1 can be synchronized with the wave recording data of station 2. If the fault occurs on the single-circuit line L3, the out-of-synchronization time t ₁₂ of the recorded wave data of station 2 and station 1 can be obtained by using the electrical quantities at both ends of the line L1, and then the station 1 and station 3 can be obtained by using the electrical quantities at both ends of the line L4 The out-of-synchronization time t ₁₃ of the wave recording data, then the out-of-synchronization time t ₂₃ of the wave recording data between the station 2 and the station 3 =t ₁₂ -t ₁₃ . Therefore, when a single-circuit line is faulty, if the two ends of the line can have the recorder data of the detour connected line, the asynchronous time of the recorded wave data at both ends of the faulty line can be obtained through the non-faulty line. For the wave recording data of a very small number of single-circuit lines or connecting lines without detours, the out-of-synchronization time can be approximated by using the data of the fault line itself. Therefore, the synchronization algorithm is divided into two types, one is the method of using the non-fault line data to synchronize the wave recording data, which is called the non-fault line data synchronization method, and the other is the method of using the fault line data to synchronize the wave recording data. It is called the fault line data synchronization method.

Non-fault Line Data Synchronization Method

For the non-fault line lumped parameter model shown in Fig. 5, set the column vector of voltage and current on side m as: U _m = [U _ma U _mb U _mc ] ^T , I _m = [I _ma I _mb I _mc ] ^T , side N The column vector of voltage and current is: U _n ＝[U _na U _nb U _nc ] ^T , In _＝ [I _na I _nb I _nc ] ^T , where U _ma represents the voltage of phase a on side m; U _mb represents the voltage on side m b-phase voltage; U _mc represents the c-phase voltage on the m side; I _ma represents the a-phase current on the m side; I _mb represents the b-phase current on the m side; I _mc represents the c-phase current on the m side; T represents the transposition of the vector .

Let Y be the admittance matrix of the transmission line to the ground. From Figure 5, for the power frequency, if the asynchronous angle on both sides of the line is δ, then:

$\frac{\mathrm{<span\; class="notranslate">\; Y</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; *</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Transpose the column vectors on both sides of formula (5) into row vectors, because Y is a symmetric matrix, then:

${<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; Y</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Assuming that the column vectors of voltage and current on side m and n after the fault are: U _mf , I _mf , U _nf , _Inf , since the line is a non-fault line, formula (5) is also valid, and we can get:

$\frac{\mathrm{<span\; class="notranslate">\; Y</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

Multiplying both sides of formula (7) by (U _m +U _n *e ^jδ ) ^T , we can get:

$\begin{array}{c}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; Y</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

Substituting formula (6) into formula (8), we get:

$\begin{array}{c}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; nf</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; mf</span>}}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

The two roots of e ^jδ can be obtained by solving the one-dimensional quadratic equation. Because |e ^jδ |=1, remove the false root, and then the out-of-synchronization angle δ can be obtained. For power frequency, out-of-synchronization time Where f is the power frequency. Wherein, e ^jδ in the above formulas is Euler's formula.

It can be seen from the above derivation that the solution of out-of-sync time is an accurate result independent of line parameters, fault type and fault point.

Fault Line Data Synchronization Method

For faulty lines, formula (7) is no longer valid, and the asynchronous time of the wave recording data at both ends of the line cannot be accurately obtained from formula (9), but formula (5) is still valid. In practical engineering applications, the three phase-to-ground admittance parameters of the transmission line are considered to be equal, and the mutual admittance is ignored, then the matrix Y is a diagonal matrix and the diagonal elements are all equal. Taking phase a as an example, formula (5) can be simplified as

$\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; na</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; ma</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ma</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; na</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

Since the conductance to ground is very small compared to the capacitive reactance to ground, and the conductance to ground is neglected, the real part of a relative to ground admittance Y _a is zero, that is:

$\mathrm{<span\; class="notranslate">\; Re</span>}<span\; class="notranslate">\; [</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; na</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; ma</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ma</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; na</span>}}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j\&delta;</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

Among them, R _e represents the real part of the complex number, and the overline represents the conjugate of the complex number.

Equation (11) can be reduced to a simple trigonometric function:

f(δ)=acosδ+bsinδ+c=0 (12)

Among them, a, b, c are the algebraic combination of the real and imaginary parts of phase a voltage and current complex numbers U _ma , U _na , I _ma , _and Ina. Solve formula (12) to get the out-of-synchronization angle, so as to realize data synchronization.

In actual implementation, the recording master station of the networked system of recorders obtains the recording data of each recorder through the acquisition module, and the data center is responsible for storing the data and providing it to the engineer station. In order to realize the association and synchronization automation of wave recording data in multiple substations, three modules are built in the fault analysis system: the clock state acquisition module of the wave recorder, the automatic association module of the wave recording data, and the automatic synchronization module of the wave recording data.

Among them, the clock status of each recorder is obtained by periodic inspection in the wave recording master station, and the time deviation T _d of the wave recorder is obtained. In a short time, this time deviation is considered to be constant. The acquisition module is responsible for inquiring and calculating the clock status of the oscilloscope, and storing it in the data center. At the same time, the engineer station can query the clock status of the entire network at any time.

The specific implementation process of the wave recording association module is shown in Figure 6. The acquisition system will regularly collect the wave recording data of the wave recorder and save them by date and device. It is defined that each recording data has a fault number (FaultNum), and if multiple faults have the same fault number (FaultNum), it is considered that they reflect the same fault and are related. After the power grid fails, the master station acquisition will obtain the wave recording data of multiple wave recorders at the first time, process them and store them in the database. The processing process is as follows: (1) The data center obtains the real-time time deviation Td to record wave data The time of the data is corrected. (2) After the correction, check whether there is any fault time associated with other fault data, and assign its fault number to this fault if there is any; if there is no fault data associated with its time, it is considered that this fault data reflects a new fault, Set a new fault number for it.

After the engineer station sends the recording association request, it will read the database according to the fault number, store the faults associated with each other together, and store the fault number and fault occurrence time at the same time.

The wave recording data automatic synchronization module is implemented in the analysis library of the data center, and the analysis object is multiple associated fault data obtained by the fault wave recording automatic association module. The synchronization process is as follows: (1) Retrieve the wave recording data according to the fault number, and match the different wave recording data in the same line. (2) Take one cycle before and after the fault for analysis. If the fault occurs outside the connecting line area of the two substations, use the non-recorded data synchronization method to automatically align the data and record the time of non-synchronization. (3) If the fault occurs on one of the double-circuit connecting lines of the two substations, it is judged whether the other circuit is faulty, and if there is no fault, the synchronization is completed through the wave recording data of the other circuit. (4) If the line is a single-circuit line, according to the synchronization time of other substation wave recording data calculated by the calculation method (2) and (3), search for the circuitous connection line channel, and calculate the synchronization time to achieve synchronization. (5) If the line is a single-circuit line and there is no detour connection line channel, the pre-fault data of the non-fault line is used to approximate synchronization.

The method for associating and synchronizing wave recording data in multiple substations of the present invention first detects the clock deviation of the wave recorders in the networked system of wave recorders in which the clock deviations of the wave recorders are relatively large, and on this basis, realizes multiple wave recording Automatic correlation of data. Make full use of the wave recording data from multiple wave recorders, no system parameters are required, and the automatic and precise synchronization of the associated wave recording data is realized. This method is realized in the networked system of the wave recorder, which is simple and convenient to operate, enables dispatchers to grasp the fault situation more timely, accurately and intuitively, and provides deeper data support for the application of power grid fault analysis on this basis.

The content of specific embodiments is described for the convenience of those skilled in the art to understand and use the present invention, and does not constitute a limitation to the protection content of the present invention. Those skilled in the art can make appropriate modifications to the present invention after reading the content of the present invention. The protection content of the present invention shall be determined by the content of the claims. Without departing from the essence and protection scope of the claims, various modifications, changes and replacements to the present invention are within the protection scope of the present invention.

Claims (4)

1. the whole network fault recorder data printenv precise synchronization method, it comprises the following steps:

(1) obtained the recorder data of each oscillograph by recorder data acquisition module, and the recorder data of acquisition is stored in data center;

(2) obtained the clock status of each oscillograph by oscillograph clock status acquisition module, and obtain the time deviation Td of each oscillograph;

(3) by recorder data auto-associating module, multiple recorder data is associated;

(4) by recorder data automatic synchronization module, multiple recorder datas be associated that described recorder data auto-associating module draws are carried out synchronously.

2. the whole network fault recorder data printenv precise synchronization method as claimed in claim 1, wherein, described step (3) is specially: a, described data center obtain described time deviation T _d, and based on described time deviation T _dthe time of the recorder data of each oscillograph is revised; B, revise after inquiry whether have associate with it the fault time of other recorder datas, have just by its fault assignment to this recorder data; If not with the recorder data of its association in time, then what think that this recorder data reflect is once new fault, establishes new fault number to it.

3. the whole network fault recorder data printenv precise synchronization method as claimed in claim 2, wherein, described step (4) is specially: a, by the recorder data in the described data center of fault number retrieval, carried out by the different recorder datas that there is same line synchronously; B, get fault occur before and after each cycle analyze, if fault occurs in outside two interconnection districts of transformer station, then with non-recorder data Synchronos method automatically synchronizing data, and record the asynchronous time; If c fault occurs on one of two transformer station's double back interconnections, then judging another loop line whether fault, as there is no fault, then completing synchronously by another loop line recorder data; If d circuit is single loop line, then according to the lock in time of the recorder data of other transformer stations calculated, searches roundabout interconnection passage, carry out calculating lock in time, realize synchronous; If e circuit is single loop line, and there is no roundabout interconnection passage, then use data near-synchronous before non-fault line fault.

4. the whole network fault recorder data printenv precise synchronization method as claimed in claim 3, wherein, the synchronous method in a in described step (4) is: first, according to the configuration of transformer station's oscillograph, extracts the common signal of each oscillograph data; Secondly, utilize the angular difference between common signal sine wave before and after whole wave Fourier transform extraction fault, calculate the asynchronous time of each oscillograph; Finally, according to the asynchronous time, by synchronous for all the other not common signal datas.